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Pathogens, Volume 9, Issue 8 (August 2020) – 74 articles

Cover Story (view full-size image): Tomato spotted wilt virus (TSWV) is a thrips-transmitted virus that causes substantial economic loss to many crops. To understand TSWV epidemiology in processing tomato fields, thrips population densities and TSWV incidences were monitored in transplant greenhouses and hundreds of fields in California’s Central Valley. Transplants were not a source of TSWV, whereas thrips and TSWV inoculum sources included winter bridge crops and weeds and varied in importance depending on the production region. The results were used to model TSWV epidemiology and to develop an integrated pest management (IPM) strategy for TSWV. Our IPM program focuses on strategic field placement, planting TSWV-free transplants, planting resistant varieties, monitoring for thrips and targeting early generations for management, roguing infected plants, sanitation, and strategic cropping to avoid overlapping with bridge crops. [...] Read more.
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16 pages, 2594 KiB  
Article
Continuous Reassortment of Clade 2.3.4.4 H5N6 Highly Pathogenetic Avian Influenza Viruses Demonstrating High Risk to Public Health
by Huanan Li, Qian Li, Bo Li, Yang Guo, Jinchao Xing, Qiang Xu, Lele Liu, Jiahao Zhang, Wenbao Qi, Weixin Jia and Ming Liao
Pathogens 2020, 9(8), 670; https://doi.org/10.3390/pathogens9080670 - 18 Aug 2020
Cited by 14 | Viewed by 3162
Abstract
Since it firstly emerged in China in 2013, clade 2.3.4.4 H5N6 highly pathogenic avian influenza viruses (HPAIVs) has rapidly replaced predominant H5N1 to become the dominant H5 subtype in China, especially in ducks. Not only endemic in China, it also crossed the geographical [...] Read more.
Since it firstly emerged in China in 2013, clade 2.3.4.4 H5N6 highly pathogenic avian influenza viruses (HPAIVs) has rapidly replaced predominant H5N1 to become the dominant H5 subtype in China, especially in ducks. Not only endemic in China, it also crossed the geographical barrier and emerged in South Korea, Japan, and Europe. Here, we analyzed the genetic properties of the clade 2.3.4.4 H5N6 HPAIVs with full genome sequences available online together with our own isolates. Phylogenetic analysis showed that clade 2.3.4.4 H5N6 HPAIVs continuously reassorted with local H5, H6, and H7N9/H9N2. Species analysis reveals that aquatic poultry and migratory birds became the dominant hosts of H5N6. Adaption to aquatic poultry might help clade 2.3.4.4 H5N6 better adapt to migratory birds, thus enabling it to become endemic in China. Besides, migratory birds might help clade 2.3.4.4 H5N6 transmit all over the world. Clade 2.3.4.4 H5N6 HPAIVs also showed a preference for α2,6-SA receptors when compared to other avian origin influenza viruses. Experiments in vitro and in vivo revealed that clade 2.3.4.4 H5N6 HPAIVs exhibited high replication efficiency in both avian and mammal cells, and it also showed high pathogenicity in both mice and chickens, demonstrating high risk to public health. Considering all the factors together, adaption to aquatic poultry and migratory birds helps clade 2.3.4.4 H5N6 overcome the geographical isolation, and it has potential to be the next influenza pandemic in the world, making it worthy of our attention. Full article
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15 pages, 2394 KiB  
Article
The Circulation of Type F Clostridium perfringens among Humans, Sewage, and Ruditapes philippinarum (Asari Clams)
by Keita Yanagimoto, Kosei Uematsu, Takaya Yamagami and Eiji Haramoto
Pathogens 2020, 9(8), 669; https://doi.org/10.3390/pathogens9080669 - 18 Aug 2020
Cited by 9 | Viewed by 3443
Abstract
Clostridium perfringens is an important pathogen that is responsible for gastroenteritis; the causative agent for the symptoms is C. perfringens enterotoxin (CPE), which is mainly produced by type F C. perfringens. Since shellfishes may gather C. perfringens in the water environment, [...] Read more.
Clostridium perfringens is an important pathogen that is responsible for gastroenteritis; the causative agent for the symptoms is C. perfringens enterotoxin (CPE), which is mainly produced by type F C. perfringens. Since shellfishes may gather C. perfringens in the water environment, this study estimated the potential circulation of type F C. perfringens among humans, sewage, and Ruditapes philippinarum (asari clams) as a result of sewage pollution. A comparison of the characteristics among the isolates from 86 sewage influents, 36 effluents, 76 asari clams, and 37 humans was conducted. Serotyping, cpe genotyping, and toxin genotyping showed that C. perfringens with a plasmid IS1151 sequence downstream of cpe was predominant among sewage influents, effluents, humans, and asari clams. Multilocus sequence typing suggested that some isolates from a human, sewage influents, effluents, and asari clams were linked to each other. These results demonstrated that asari clams are the necessary infection sources of C. perfringens responsible for carriers and foodborne diseases, and that these pathogens from humans infected by asari clams can pollute the water environment. It is useful to assess bacteria such as C. perfringens isolates from sewage to estimate the trend of those from the community. Full article
(This article belongs to the Section Waterborne/Foodborne/Airborne Pathogens)
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14 pages, 900 KiB  
Article
Effect of Serotype and Strain Diversity on Dengue Virus Replication in Australian Mosquito Vectors
by O’mezie Ekwudu, Louise Marquart, Lachlan Webb, Kym S. Lowry, Gregor J. Devine, Leon E. Hugo and Francesca D. Frentiu
Pathogens 2020, 9(8), 668; https://doi.org/10.3390/pathogens9080668 - 18 Aug 2020
Cited by 8 | Viewed by 3322
Abstract
Dengue virus (DENV) is the most important mosquito-borne viral pathogen of humans, comprising four serotypes (DENV-1 to -4) with a myriad of genotypes and strains. The kinetics of DENV replication within the mosquito following ingestion of a blood meal influence the pathogen’s ability [...] Read more.
Dengue virus (DENV) is the most important mosquito-borne viral pathogen of humans, comprising four serotypes (DENV-1 to -4) with a myriad of genotypes and strains. The kinetics of DENV replication within the mosquito following ingestion of a blood meal influence the pathogen’s ability to reach the salivary glands and thus the transmission potential. The influence of DENV serotype and strain diversity on virus kinetics in the two main vector species, Aedes aegypti and Ae. albopictus, has been poorly characterized. We tested whether DENV replication kinetics vary systematically among serotypes and strains, using Australian strains of the two vectors. Mosquitoes were blood fed with two strains per serotype, and sampled at 3, 6, 10 and 14-days post-exposure. Virus infection in mosquito bodies, and dissemination of virus to legs and wings, was detected using qRT-PCR. For both vectors, we found significant differences among serotypes in proportions of mosquitoes infected, with higher numbers for DENV-1 and -2 versus other serotypes. Consistent with this, we observed that DENV-1 and -2 generally replicated to higher RNA levels than other serotypes, particularly at earlier time points. There were no significant differences in either speed of infection or dissemination between the mosquito species. Our results suggest that DENV diversity may have important epidemiological consequences by influencing virus kinetics in mosquito vectors. Full article
(This article belongs to the Section Animal Pathogens)
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21 pages, 409 KiB  
Review
Water as a Source of Antimicrobial Resistance and Healthcare-Associated Infections
by Claire Hayward, Kirstin E. Ross, Melissa H. Brown and Harriet Whiley
Pathogens 2020, 9(8), 667; https://doi.org/10.3390/pathogens9080667 - 18 Aug 2020
Cited by 20 | Viewed by 4621
Abstract
Healthcare-associated infections (HAIs) are one of the most common patient complications, affecting 7% of patients in developed countries each year. The rise of antimicrobial resistant (AMR) bacteria has been identified as one of the biggest global health challenges, resulting in an estimated 23,000 [...] Read more.
Healthcare-associated infections (HAIs) are one of the most common patient complications, affecting 7% of patients in developed countries each year. The rise of antimicrobial resistant (AMR) bacteria has been identified as one of the biggest global health challenges, resulting in an estimated 23,000 deaths in the US annually. Environmental reservoirs for AMR bacteria such as bed rails, light switches and doorknobs have been identified in the past and addressed with infection prevention guidelines. However, water and water-related devices are often overlooked as potential sources of HAI outbreaks. This systematic review examines the role of water and water-related devices in the transmission of AMR bacteria responsible for HAIs, discussing common waterborne devices, pathogens, and surveillance strategies. AMR strains of previously described waterborne pathogens including Pseudomonas aeruginosa, Mycobacterium spp., and Legionella spp. were commonly isolated. However, methicillin-resistant Staphylococcus aureus and carbapenem-resistant Enterobacteriaceae that are not typically associated with water were also isolated. Biofilms were identified as a hot spot for the dissemination of genes responsible for survival functions. A limitation identified was a lack of consistency between environmental screening scope, isolation methodology, and antimicrobial resistance characterization. Broad universal environmental surveillance guidelines must be developed and adopted to monitor AMR pathogens, allowing prediction of future threats before waterborne infection outbreaks occur. Full article
(This article belongs to the Section Waterborne/Foodborne/Airborne Pathogens)
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14 pages, 933 KiB  
Article
Cystatin C and α-1-Microglobulin Predict Severe Acute Kidney Injury in Patients with Hemorrhagic Fever with Renal Syndrome
by Magnus Hansson, Rasmus Gustafsson, Chloé Jacquet, Nedia Chebaane, Simon Satchell, Therese Thunberg, Clas Ahlm and Anne-Marie Fors Connolly
Pathogens 2020, 9(8), 666; https://doi.org/10.3390/pathogens9080666 - 18 Aug 2020
Cited by 15 | Viewed by 3313
Abstract
Puumala orthohantavirus causes hemorrhagic fever with renal syndrome (HFRS) characterized by acute kidney injury (AKI), an abrupt decrease in renal function. Creatinine is routinely used to detect and quantify AKI; however, early AKI may not be reflected in increased creatinine levels. Therefore, kidney [...] Read more.
Puumala orthohantavirus causes hemorrhagic fever with renal syndrome (HFRS) characterized by acute kidney injury (AKI), an abrupt decrease in renal function. Creatinine is routinely used to detect and quantify AKI; however, early AKI may not be reflected in increased creatinine levels. Therefore, kidney injury markers that can predict AKI are needed. The potential of the kidney injury markers urea, cystatin C, α1-microglobulin (A1M) and neutrophil gelatinase-associated lipocalin (NGAL) to detect early AKI during HFRS was studied by quantifying the levels of these markers in consecutively obtained plasma (P) and urine samples (U) for 44 HFRS patients. P-cystatin C and U-A1M levels were significantly increased during early HFRS compared to follow-up. In a receiver operating characteristic (ROC) curve analysis, P-cystatin C, U-A1M and P-urea predicted severe AKI with area under the curve 0.72, 0.73 and 0.71, respectively, whereas the traditional kidney injury biomarkers creatinine and U-albumin did not predict AKI. Nearly half of the HFRS patients (41%) fulfilled the criteria for shrunken pore syndrome, which was associated with the level of inflammation as measured by P-CRP. P-cystatin C and U-A1M are more sensitive and earlier markers compared to creatinine in predicting kidney injury during HFRS. Full article
(This article belongs to the Special Issue Hemorrhagic Fever Viruses)
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15 pages, 1034 KiB  
Article
Molecular Epidemiology Reveals Low Genetic Diversity among Cryptococcus neoformans Isolates from People Living with HIV in Lima, Peru, during the Pre-HAART Era
by Nathalie van de Wiele, Edgar Neyra, Carolina Firacative, Felix Gilgado, Carolina Serena, Beatriz Bustamante and Wieland Meyer
Pathogens 2020, 9(8), 665; https://doi.org/10.3390/pathogens9080665 - 18 Aug 2020
Cited by 7 | Viewed by 2892
Abstract
Cryptococcosis, a mycosis presenting mostly as meningoencephalitis, affecting predominantly human immunodeficiency virus (HIV)-infected people, is mainly caused by Cryptococcus neoformans. The genetic variation of 48 C. neoformans isolates, recovered from 20 HIV-positive people in Lima, Peru, during the pre-highly active antiretroviral therapy [...] Read more.
Cryptococcosis, a mycosis presenting mostly as meningoencephalitis, affecting predominantly human immunodeficiency virus (HIV)-infected people, is mainly caused by Cryptococcus neoformans. The genetic variation of 48 C. neoformans isolates, recovered from 20 HIV-positive people in Lima, Peru, during the pre-highly active antiretroviral therapy (HAART) era, was studied retrospectively. The mating type of the isolates was determined by PCR, and the serotype by agglutination and CAP59-restriction fragment length polymorphism (RFLP). Genetic diversity was assessed by URA5-RFLP, PCR-fingerprinting, amplified fragment length polymorphism (AFLP), and multilocus sequence typing (MLST). All isolates were mating type alpha, with 39 molecular type VNI, seven VNII, corresponding to C. neoformans var. grubii serotype A, and two VNIII AD hybrids. Overall, the cryptococcal population from HIV-positive people in Lima shows a low degree of genetic diversity. In most patients with persistent cryptococcal infection, the same genotype was recovered during the follow-up. In four patients with relapse and one with therapy failure, different genotypes were found in isolates from the re-infection and from the isolate recovered at the end of the treatment. In one patient, two genotypes were found in the first cryptococcosis episode. This study contributes data from Peru to the ongoing worldwide population genetic analysis of Cryptococcus. Full article
(This article belongs to the Section Human Pathogens)
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13 pages, 1419 KiB  
Review
Pathogens Manipulating Tick Behavior—Through a Glass, Darkly
by Giovanni Benelli
Pathogens 2020, 9(8), 664; https://doi.org/10.3390/pathogens9080664 - 17 Aug 2020
Cited by 43 | Viewed by 11491
Abstract
Pathogens can manipulate the phenotypic traits of their hosts and vectors, maximizing their own fitness. Among the phenotypic traits that can be modified, manipulating vector behavior represents one of the most fascinating facets. How pathogens infection affects behavioral traits of key insect vectors [...] Read more.
Pathogens can manipulate the phenotypic traits of their hosts and vectors, maximizing their own fitness. Among the phenotypic traits that can be modified, manipulating vector behavior represents one of the most fascinating facets. How pathogens infection affects behavioral traits of key insect vectors has been extensively investigated. Major examples include Plasmodium, Leishmania and Trypanosoma spp. manipulating the behavior of mosquitoes, sand flies and kissing bugs, respectively. However, research on how pathogens can modify tick behavior is patchy. This review focuses on current knowledge about the behavioral changes triggered by Anaplasma, Borrelia, Babesia, Bartonella, Rickettsia and tick-borne encephalitis virus (TBEV) infection in tick vectors, analyzing their potential adaptive significance. As a general trend, being infected by Borrelia and TBEV boosts tick mobility (both questing and walking activity). Borrelia and Anaplasma infection magnifies Ixodes desiccation resistance, triggering physiological changes (Borrelia: higher fat reserves; Anaplasma: synthesis of heat shock proteins). Anaplasma infection also improves cold resistance in infected ticks through synthesis of an antifreeze glycoprotein. Being infected by Anaplasma, Borrelia and Babesia leads to increased tick survival. Borrelia, Babesia and Bartonella infection facilitates blood engorgement. In the last section, current challenges for future studies are outlined. Full article
(This article belongs to the Special Issue Animal Parasitic Diseases)
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22 pages, 1268 KiB  
Article
Molecular Characterisation of a Rare Reassortant Porcine-Like G5P[6] Rotavirus Strain Detected in an Unvaccinated Child in Kasama, Zambia
by Wairimu M. Maringa, Peter N. Mwangi, Julia Simwaka, Evans M. Mpabalwani, Jason M. Mwenda, Ina Peenze, Mathew D. Esona, M. Jeffrey Mphahlele, Mapaseka L. Seheri and Martin M. Nyaga
Pathogens 2020, 9(8), 663; https://doi.org/10.3390/pathogens9080663 - 17 Aug 2020
Cited by 15 | Viewed by 3964
Abstract
A human-porcine reassortant strain, RVA/Human-wt/ZMB/UFS-NGS-MRC-DPRU4723/2014/G5P[6], was identified in a sample collected in 2014 from an unvaccinated 12 month old male hospitalised for gastroenteritis in Zambia. We sequenced and characterised the complete genome of this strain which presented the constellation: G5-P[6]-I1-R1-C1-M1-A8-N1-T1-E1-H1. The genotype A8 [...] Read more.
A human-porcine reassortant strain, RVA/Human-wt/ZMB/UFS-NGS-MRC-DPRU4723/2014/G5P[6], was identified in a sample collected in 2014 from an unvaccinated 12 month old male hospitalised for gastroenteritis in Zambia. We sequenced and characterised the complete genome of this strain which presented the constellation: G5-P[6]-I1-R1-C1-M1-A8-N1-T1-E1-H1. The genotype A8 is often observed in porcine strains. Phylogenetic analyses showed that VP6, VP7, NSP2, NSP4, and NSP5 genes were closely related to cognate gene sequences of porcine strains (e.g., RVA/Pig-wt/CHN/DZ-2/2013/G5P[X] for VP7) from the NCBI database, while VP1, VP3, VP4, and NSP3 were closely related to porcine-like human strains (e.g., RVA/Human-wt/CHN/E931/2008/G4P[6] for VP1, and VP3). On the other hand, the origin of the VP2 was not clear from our analyses, as it was not only close to both porcine (e.g., RVA/Pig-tc/CHN/SWU-1C/2018/G9P[13]) and porcine-like human strains (e.g., RVA/Human-wt/LKA/R1207/2009/G4P[6]) but also to three human strains (e.g., RVA/Human-wt/USA/1476/1974/G1P[8]). The VP7 gene was located in lineage II that comprised only porcine strains, which suggests the occurrence of independent porcine-to-human reassortment events. The study strain may have collectively been derived through interspecies transmission, or through reassortment event(s) involving strains of porcine and porcine-like human origin. The results of this study underline the importance of whole-genome characterisation of rotavirus strains and provide insights into interspecies transmissions from porcine to humans. Full article
(This article belongs to the Special Issue Rotaviruses and Rotavirus Vaccines)
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23 pages, 10018 KiB  
Article
Comparative Pathology of Domestic Pigs and Wild Boar Infected with the Moderately Virulent African Swine Fever Virus Strain “Estonia 2014”
by Julia Sehl, Jutta Pikalo, Alexander Schäfer, Kati Franzke, Katrin Pannhorst, Ahmed Elnagar, Ulrike Blohm, Sandra Blome and Angele Breithaupt
Pathogens 2020, 9(8), 662; https://doi.org/10.3390/pathogens9080662 - 16 Aug 2020
Cited by 29 | Viewed by 4037
Abstract
Endemically infected European wild boar are considered a major reservoir of African swine fever virus in Europe. While high lethality was observed in the majority of field cases, strains of moderate virulence occurred in the Baltic States. One of these, “Estonia 2014”, led [...] Read more.
Endemically infected European wild boar are considered a major reservoir of African swine fever virus in Europe. While high lethality was observed in the majority of field cases, strains of moderate virulence occurred in the Baltic States. One of these, “Estonia 2014”, led to a higher number of clinically healthy, antibody-positive animals in the hunting bag of North-Eastern Estonia. Experimental characterization showed high virulence in wild boar but moderate virulence in domestic pigs. Putative pathogenic differences between wild boar and domestic pigs are unresolved and comparative pathological studies are limited. We here report on a kinetic experiment in both subspecies. Three animals each were euthanized at 4, 7, and 10 days post infection (dpi). Clinical data confirmed higher virulence in wild boar although macroscopy and viral genome load in blood and tissues were comparable in both subspecies. The percentage of viral antigen positive myeloid cells tested by flow cytometry did not differ significantly in most tissues. Only immunohistochemistry revealed consistently higher viral antigen loads in wild boar tissues in particular 7 dpi, whereas domestic pigs already eliminated the virus. The moderate virulence in domestic pigs could be explained by a more effective viral clearance. Full article
(This article belongs to the Special Issue African Swine Fever Virus Infection)
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21 pages, 1606 KiB  
Review
Trypanosomatid Infections among Vertebrates of Chile: A Systematic Review
by Juana P. Correa, Antonella Bacigalupo, Esteban Yefi-Quinteros, Gemma Rojo, Aldo Solari, Pedro E. Cattan and Carezza Botto-Mahan
Pathogens 2020, 9(8), 661; https://doi.org/10.3390/pathogens9080661 - 16 Aug 2020
Cited by 17 | Viewed by 4087
Abstract
We present a review on the natural infection by trypanosomatids of nonhuman vertebrates in Chile, aiming to synthesize and update the knowledge on the diversity of trypanosomatids infecting native and alien vertebrate species. To this end, we conducted a systematic review of literature [...] Read more.
We present a review on the natural infection by trypanosomatids of nonhuman vertebrates in Chile, aiming to synthesize and update the knowledge on the diversity of trypanosomatids infecting native and alien vertebrate species. To this end, we conducted a systematic review of literature records published from 1900 to April 2020 on four databases, focusing on the 21 genera of trypanosomatids and Chile. The methods and findings of our review have been based on the preferred reporting items for systematic reviews and meta-analysis (prisma) checklist. We found 29,756 records but only 71 presented relevant information for this review. Overall, there are only two reported trypanosomatid genera infecting vertebrate species in Chile, the genera Trypanosoma and Leishmania. The former is mostly represented by Trypanosoma cruzi (90% of the total records) and to a much lesser extent by Trypanosoma avium, Trypanosoma humboldti, Trypanosoma lewisi, and a couple of unidentified trypanosomatids. A total of 25 mammals have been reported as being infected by T. cruzi, including 14 native and 11 alien species from Orders Artiodactyla, Carnivora, Chiroptera, Didelphimorphia, Lagomorpha, Perissodactyla, and Rodentia. Extensive screening studies using new analytical tools are necessary to grasp the whole potential diversity of trypanosomatid species infecting vertebrates in Chile. Full article
(This article belongs to the Special Issue Trypanosomatid Infections Among Wild Fauna)
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14 pages, 3856 KiB  
Article
Epidemiological Trends of Five Common Diarrhea-Associated Enteric Viruses Pre- and Post-Rotavirus Vaccine Introduction in Coastal Kenya
by Arnold W. Lambisia, Sylvia Onchaga, Nickson Murunga, Clement S. Lewa, Steven Ger Nyanjom and Charles N. Agoti
Pathogens 2020, 9(8), 660; https://doi.org/10.3390/pathogens9080660 - 15 Aug 2020
Cited by 15 | Viewed by 3683
Abstract
Using real-time RT-PCR, we screened stool samples from children aged <5 years presenting with diarrhea and admitted to Kilifi County Hospital, coastal Kenya, pre- (2003 and 2013) and post-rotavirus vaccine introduction (2016 and 2019) for five viruses, namely rotavirus group A (RVA), norovirus [...] Read more.
Using real-time RT-PCR, we screened stool samples from children aged <5 years presenting with diarrhea and admitted to Kilifi County Hospital, coastal Kenya, pre- (2003 and 2013) and post-rotavirus vaccine introduction (2016 and 2019) for five viruses, namely rotavirus group A (RVA), norovirus GII, adenovirus, astrovirus and sapovirus. Of the 984 samples analyzed, at least one virus was detected in 401 (40.8%) patients. Post rotavirus vaccine introduction, the prevalence of RVA decreased (23.3% vs. 13.8%, p < 0.001) while that of norovirus GII increased (6.6% vs. 10.9%, p = 0.023). The prevalence of adenovirus, astrovirus and sapovirus remained statistically unchanged between the two periods: 9.9% vs. 14.2%, 2.4% vs. 3.2 %, 4.6% vs. 2.6%, (p = 0.053, 0.585 and 0.133), respectively. The median age of diarrhea cases was higher post vaccine introduction (12.5 months, interquartile range (IQR): 7.9–21 vs. 11.2 months pre-introduction, IQR: 6.8–16.5, p < 0.001). In this setting, RVA and adenovirus cases peaked in the dry months while norovirus GII and sapovirus peaked in the rainy season. Astrovirus did not display clear seasonality. In conclusion, following rotavirus vaccine introduction, we found a significant reduction in the prevalence of RVA in coastal Kenya but an increase in norovirus GII prevalence in hospitalized children. Full article
(This article belongs to the Special Issue Rotaviruses and Rotavirus Vaccines)
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20 pages, 1719 KiB  
Article
BLIGHTSIM: A New Potato Late Blight Model Simulating the Response of Phytophthora infestans to Diurnal Temperature and Humidity Fluctuations in Relation to Climate Change
by Hossein A. Narouei-Khandan, Shankar K. Shakya, Karen A. Garrett, Erica M. Goss, Nicholas S. Dufault, Jorge L. Andrade-Piedra, Senthold Asseng, Daniel Wallach and Ariena H.C van Bruggen
Pathogens 2020, 9(8), 659; https://doi.org/10.3390/pathogens9080659 - 15 Aug 2020
Cited by 15 | Viewed by 5111
Abstract
Temperature response curves under diurnal oscillating temperatures differ from those under constant conditions for all stages of the Phytophthora infestans infection cycle on potatoes. We developed a mechanistic model (BLIGHTSIM) with an hourly time step to simulate late blight under fluctuating environmental conditions [...] Read more.
Temperature response curves under diurnal oscillating temperatures differ from those under constant conditions for all stages of the Phytophthora infestans infection cycle on potatoes. We developed a mechanistic model (BLIGHTSIM) with an hourly time step to simulate late blight under fluctuating environmental conditions and predict late blight epidemics in potato fields. BLIGHTSIM is a modified susceptible (S), latent (L), infectious (I) and removed (R) compartmental model with hourly temperature and relative humidity as driving variables. The model was calibrated with growth chamber data covering one infection cycle and validated with field data from Ecuador. The model provided a good fit to all data sets evaluated. There was a significant interaction between average temperature and amplitude in their effects on the area under the disease progress curve (AUDPC) as predicted from growth chamber data on a single infection cycle. BLIGHTSIM can be incorporated in a potato growth model to study effects of diurnal temperature range on late blight impact under climate change scenarios. Full article
(This article belongs to the Section Plant Pathogens)
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17 pages, 653 KiB  
Review
Recent Advances in the Diagnosis of Classical Swine Fever and Future Perspectives
by Lihua Wang, Rachel Madera, Yuzhen Li, David Scott McVey, Barbara S. Drolet and Jishu Shi
Pathogens 2020, 9(8), 658; https://doi.org/10.3390/pathogens9080658 - 15 Aug 2020
Cited by 19 | Viewed by 5303
Abstract
Classical swine fever (CSF) is a highly contagious viral disease of pigs, including wild boar. It is regarded as one of the major problems in the pig industry as it is still endemic in many regions of the world and has the potential [...] Read more.
Classical swine fever (CSF) is a highly contagious viral disease of pigs, including wild boar. It is regarded as one of the major problems in the pig industry as it is still endemic in many regions of the world and has the potential to cause devastating epidemics, particularly in countries free of the disease. Rapid and reliable diagnosis is of utmost importance in the control of CSF. Since clinical presentations of CSF are highly variable and may be confused with other viral diseases in pigs, laboratory diagnosis is indispensable for an unambiguous diagnosis. On an international level, well-established diagnostic tests of CSF such as virus isolation, fluorescent antibody test (FAT), antigen capture antibody enzyme-linked immunosorbent assay (ELISA), reverse-transcription polymerase chain reaction (RT-PCR), virus neutralization test (VNT), and antibody ELISA have been described in detail in the OIE Terrestrial Manual. However, improved CSF diagnostic methods or alternatives based on modern technologies have been developed in recent years. This review thus presents recent advances in the diagnosis of CSF and future perspectives. Full article
(This article belongs to the Special Issue Classical Swine Fever)
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7 pages, 197 KiB  
Article
Growth Temperature, Trehalose, and Susceptibility to Heat in Mycobacterium avium
by Simonne Guenette, Myra D. Williams and Joseph O. Falkinham III
Pathogens 2020, 9(8), 657; https://doi.org/10.3390/pathogens9080657 - 15 Aug 2020
Cited by 9 | Viewed by 2274
Abstract
Mycobacterium avium is capable of an adaptive, reversible response to high-temperature survival depending on its growth temperature. Trehalose concentrations of M. avium cells grown at 42 °C were significantly higher compared to those of cells grown at 25 °C. Further, the survival of [...] Read more.
Mycobacterium avium is capable of an adaptive, reversible response to high-temperature survival depending on its growth temperature. Trehalose concentrations of M. avium cells grown at 42 °C were significantly higher compared to those of cells grown at 25 °C. Further, the survival of cells of M. avium grown at 42 °C and exposed to 65 °C were significantly higher than the survival of cells grown at 25 °C. This adaptive response to growth temperature may play a role in the persistence of M. avium in premise plumbing. Full article
5 pages, 219 KiB  
Case Report
Salmonella Hessarek Gastroenteritis with Bacteremia: A Case Report and Literature Review
by Pierangelo Chinello, Guido Granata, Vincenzo Galati, Fabrizio Taglietti, Simone Topino, Emanuela Caraffa, Carolina Venditti, Nazario Bevilacqua, Lucilla Sbardella, Stefano Bilei and Nicola Petrosillo
Pathogens 2020, 9(8), 656; https://doi.org/10.3390/pathogens9080656 - 15 Aug 2020
Cited by 2 | Viewed by 2473
Abstract
Salmonella enterica subspecies enterica serotype Hessarek (Salmonella Hessarek) is considered a serovar with high host specificity and is an uncommon cause of disease in humans; no cases of S. Hessarek bacteremia have been reported in humans to date. On 16 July 2019, [...] Read more.
Salmonella enterica subspecies enterica serotype Hessarek (Salmonella Hessarek) is considered a serovar with high host specificity and is an uncommon cause of disease in humans; no cases of S. Hessarek bacteremia have been reported in humans to date. On 16 July 2019, a young male presented abdominal pain, vomit, diarrhea, and fever up to 41 °C, a few hours after a kebab meal containing goat meat; he went to the Emergency Room, where a Film Array® GI Panel (BioFire, Biomerieux Company, Marcy-L´Étoile, France) was performed on his feces and results were positive for Salmonella. The culture of the feces was negative, but the blood culture was positive for Salmonella spp., which was identified as Salmonella Hessarek by seroagglutination assays. The patient was treated with ceftriaxone 2 g intravenously qd for 8 days; he was discharged in good general conditions, and ciprofloxacin 500 mg per os bid for 7 more days was prescribed, after exclusion of endocarditis and of clinical signs of complicated bacteremia. This case of Salmonella Hessarek gastroenteritis with bacteremia is probably the first case of bloodstream human infection due to this agent ever described. Further studies are needed to ascertain the global burden of S. Hessarek disease in humans. Full article
12 pages, 4179 KiB  
Article
Coordinated In Vitro Release of Granulysin, Perforin and IFN-γ in TB and HIV/TB Co-Infection Associated with Clinical Outcomes before and after Anti-TB Treatment
by Nada Pitabut, Panadda Dhepakson, Shinsaku Sakurada, Naoto Keicho and Srisin Khusmith
Pathogens 2020, 9(8), 655; https://doi.org/10.3390/pathogens9080655 - 14 Aug 2020
Cited by 4 | Viewed by 3037
Abstract
Granule-associated killing molecules released from cytotoxic T lymphocytes participate as a crucial step in immunity against tuberculosis (TB), but the role of coordinated production remains controversial. Coordinated release of effector molecules in vitro after stimulating peripheral blood mononuclear cells (PBMCs) of active TB [...] Read more.
Granule-associated killing molecules released from cytotoxic T lymphocytes participate as a crucial step in immunity against tuberculosis (TB), but the role of coordinated production remains controversial. Coordinated release of effector molecules in vitro after stimulating peripheral blood mononuclear cells (PBMCs) of active TB or HIV/TB coinfection patients with PPD, purified protein derivative of tuberculin and avirulent Mtb, H37Ra, an attenuated strain were investigated in association with clinical outcomes. Perforin, granzyme-B, granulysin and IFN-γ were measured using ELISA. Before anti-TB treatment, PBMCs of TB stimulated with PPD or H37Ra released higher perforin, granzyme-B, and granulysin levels than in HIV/TB and released significantly higher IFN-γ (p = 0.045, p = 0.022). Granulysin positively correlated with perforin in TB (p = 0.042, r = 0.385), HIV/TB coinfection (p = 0.003, r = 0.941) after PPD stimulation, and after H37Ra stimulation in TB (p = 0.005, r = 0.549), but negatively correlated with granzyme B in TB (p = 0.042, r = −0.386), HIV/TB coinfection (p = 0.042, r = 0.754) were noted. After anti-TB treatment, increased levels of perforin, granulysin and IFN-γ in TB or HIV/TB upon PPD or H37Ra stimulation, and decreased granzyme-B levels after PPD (p = 0.003) or H37Ra (p = 0.028) stimulation in TB were observed. These results suggest that granulysin may act synergistic with perforin and IFN-γ in TB, indicating its crucial function in host immunity to tuberculosis. Future studies with larger numbers of patients ought to be conducted in the future. Full article
(This article belongs to the Section Immunological Responses and Immune Defense Mechanisms)
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12 pages, 265 KiB  
Article
Biofilm Formation Ability and Presence of Adhesion Genes among Coagulase-Negative and Coagulase-Positive Staphylococci Isolates from Raw Cow’s Milk
by Joanna Gajewska and Wioleta Chajęcka-Wierzchowska
Pathogens 2020, 9(8), 654; https://doi.org/10.3390/pathogens9080654 - 14 Aug 2020
Cited by 28 | Viewed by 4185
Abstract
The capacity for biofilm formation is one of the crucial factors of staphylococcal virulence. The occurrence of biofilm-forming staphylococci in raw milk may result in disturbances in technological processes in dairy factories as well as the contamination of finished food products. Therefore, this [...] Read more.
The capacity for biofilm formation is one of the crucial factors of staphylococcal virulence. The occurrence of biofilm-forming staphylococci in raw milk may result in disturbances in technological processes in dairy factories as well as the contamination of finished food products. Therefore, this study aimed to determine the prevalence and characteristics of staphylococcal biofilm formation in raw milk samples and to explore the genetic background associated with biofilm formation in those isolates. The material subjected to testing included 30 cow’s milk samples acquired from farms in the central part of Poland. A total of 54 staphylococcal strains were isolated from the samples, of which 42 were classified as coagulase-negative (CoNS) staphylococci belonging to the following species: S. haemolyticus, S. simulans, S. warneri, S. chromogenes, S. hominis, S. sciuri, S. capitis, S. xylosus and S. saprophyticus, while 12 were classified as S. aureus. The study examined the isolates’ capacity for biofilm formation and the staphylococcal capacity for slime production and determined the presence of genetic determinants responsible for biofilm formation, i.e., the icaA, icaD, bap and eno and, additionally, among coagulase-negative staphylococci, i.e., the aap, bhp, fbe, embP and atlE. Each tested isolate exhibited the capacity for biofilm formation, of which most of them (79.6%) were capable of forming a strong biofilm, while 5.6% formed a moderate biofilm, and 14.8% a weak biofilm. A capacity for slime production was demonstrated in 51.9% isolates. Most of the tested staphylococcal strains (90.7%) had at least one of the tested genes. Nearly half (47.6%) of the CoNS had the eno gene, while for S. aureus, the eno gene was demonstrated in 58.3% isolates. The frequency of the bap gene occurrence was 23.8% and 25% in CoNS strains and S. aureus, respectively. The fbe gene was demonstrated in only three CoNS isolates. The presence of the icaA was only demonstrated in CoNS strains (24.1%), while the icaD was found in both CoNS strains (21.4%) and S. aureus (100%). Among the CoNS, the presence of the embP (16.7%), aap (28.6%) and atlE (23.8%) was demonstrated as well. The obtained study results indicate that bacteria of the Staphylococcus spp. genus have a strong potential to form a biofilm, which may pose a hazard to consumer health. Full article
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9 pages, 9962 KiB  
Article
Oral Ingestion of Synthetically Generated Recombinant Prion Is Sufficient to Cause Prion Disease in Wild-Type Mice
by Chenhua Pan, Junwei Yang, Xiangyi Zhang, Ying Chen, Shunxiong Wei, Guohua Yu, Yi-Hsuan Pan, Jiyan Ma and Chonggang Yuan
Pathogens 2020, 9(8), 653; https://doi.org/10.3390/pathogens9080653 - 13 Aug 2020
Cited by 7 | Viewed by 2616
Abstract
Prion disease is a group of transmissible neurodegenerative disorders affecting humans and animals. The prion hypothesis postulates that PrPSc, the pathogenic conformer of host-encoded prion protein (PrP), is the unconventional proteinaceous infectious agent called prion. Supporting this hypothesis, highly infectious prion [...] Read more.
Prion disease is a group of transmissible neurodegenerative disorders affecting humans and animals. The prion hypothesis postulates that PrPSc, the pathogenic conformer of host-encoded prion protein (PrP), is the unconventional proteinaceous infectious agent called prion. Supporting this hypothesis, highly infectious prion has been generated in vitro with recombinant PrP plus defined non-protein cofactors and the synthetically generated prion (recPrPSc) is capable of causing prion disease in wild-type mice through intracerebral (i.c.) or intraperitoneal (i.p.) inoculation. Given that many of the naturally occurring prion diseases are acquired through oral route, demonstrating the capability of recPrPSc to cause prion disease via oral transmission is important, but has never been proven. Here we showed for the first time that oral ingestion of recPrPSc is sufficient to cause prion disease in wild-type mice, which was supported by the development of fatal neurodegeneration in exposed mice, biochemical and histopathological analyses of diseased brains, and second round transmission. Our results demonstrate the oral transmissibility of recPrPSc and provide the missing evidence to support that the in vitro generated recPrPSc recapitulates all the important properties of naturally occurring prions. Full article
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15 pages, 2115 KiB  
Article
Comparison of Coxiella burnetii Excretion between Sheep and Goats Naturally Infected with One Cattle-Associated Genotype
by Benjamin Bauer, Louise Prüfer, Mathias Walter, Isabel Ganter, Dimitrios Frangoulidis, Martin Runge and Martin Ganter
Pathogens 2020, 9(8), 652; https://doi.org/10.3390/pathogens9080652 - 13 Aug 2020
Cited by 18 | Viewed by 3203
Abstract
The main reservoir of Coxiella (C.) burnetii are ruminants. They shed the pathogen through birth products, vaginal mucus, faeces and milk. A direct comparison of C. burnetii excretions between naturally infected sheep and goats was performed on the same farm to investigate species-specific [...] Read more.
The main reservoir of Coxiella (C.) burnetii are ruminants. They shed the pathogen through birth products, vaginal mucus, faeces and milk. A direct comparison of C. burnetii excretions between naturally infected sheep and goats was performed on the same farm to investigate species-specific differences. The animals were vaccinated with an inactivated C. burnetii phase I vaccine at the beginning of the study period for public health reasons. Vaginal and rectal swabs along with milk specimens were taken monthly during the lambing period and once again at the next lambing season. To estimate the environmental contamination of the animals’ housings, nasal swabs from every animal were taken simultaneously. Moreover, dust samples from the windowsills and straw beddings were collected. All samples were examined by qPCR targeting the IS1111 gene and the MLVA/VNTR typing method was performed. Whole genome sequencing was applied to determine the number of IS1111 copies followed by a calculation of C. burnetii genome equivalents of each sample. The cattle-associated genotype C7 was detected containing 29 IS1111 copies. Overall, goats seem to shed more C. burnetii through vaginal mucus and in particular shed more and for longer via the rectal route than sheep. This is supported by the larger quantities of C. burnetii DNA detected in caprine nasal swabs and environmental samples compared to the ovine ones. Transmission of C. burnetii from cattle to small ruminants must also be considered. Full article
(This article belongs to the Special Issue Q Fever)
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11 pages, 1643 KiB  
Review
Microbial Contamination of Dental Unit Waterlines and Potential Risk of Infection: A Narrative Review
by Anna Maria Spagnolo, Marina Sartini and Maria Luisa Cristina
Pathogens 2020, 9(8), 651; https://doi.org/10.3390/pathogens9080651 - 13 Aug 2020
Cited by 24 | Viewed by 3909
Abstract
Several studies have revealed that dental unit waterlines (DUWLs) are often contaminated by large numbers of various micro-organisms (bacteria, fungi, protozoa, viruses). Microbial contamination in DUWLs may originate from the mains water piped into the dental unit, the suck-back of patients’ saliva into [...] Read more.
Several studies have revealed that dental unit waterlines (DUWLs) are often contaminated by large numbers of various micro-organisms (bacteria, fungi, protozoa, viruses). Microbial contamination in DUWLs may originate from the mains water piped into the dental unit, the suck-back of patients’ saliva into the line due to the lack of adequate valves, and contamination from bottled water systems. Some of the main determinants of microbial contamination in DUWLs are: a very small lumen size (0.5–2 mm) of the tubing used, high surface-to-volume ratio (6:1), low throughput and the materials of which the tubing is made, water stagnation outside of working hours. The environmental conditions present inside the conduits of the dental unit may facilitate the proliferation of micro-organisms and the consequent formation of biofilm on the interior surface of the pipes of DUWLs. During the use of handpieces, particularly high-speed rotating instruments, a spray is thrown up in the form of aerosols or spatters containing biological material (saliva, blood and dental plaque) and micro-organisms. This means that the health of both dental staff and patients could be at risk of infection. The risk of cross-infections in dental settings can be tackled by implementing combined interventions to prevent the contamination of DUWLs. Full article
(This article belongs to the Special Issue Healthcare-Associated Infections)
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15 pages, 5501 KiB  
Article
The CMV-Specific CD8+ T Cell Response Is Dominated by Supra-Public Clonotypes with High Generation Probabilities
by Kilian Schober, Pim Fuchs, Jonas Mir, Monika Hammel, Lorenzo Fanchi, Michael Flossdorf and Dirk H. Busch
Pathogens 2020, 9(8), 650; https://doi.org/10.3390/pathogens9080650 - 13 Aug 2020
Cited by 2 | Viewed by 3258
Abstract
Evolutionary processes govern the selection of T cell clonotypes that are optimally suited to mediate efficient antigen-specific immune responses against pathogens and tumors. While the theoretical diversity of T cell receptor (TCR) sequences is vast, the antigen-specific TCR repertoire is restricted by its [...] Read more.
Evolutionary processes govern the selection of T cell clonotypes that are optimally suited to mediate efficient antigen-specific immune responses against pathogens and tumors. While the theoretical diversity of T cell receptor (TCR) sequences is vast, the antigen-specific TCR repertoire is restricted by its peptide epitope and the presenting major histocompatibility complex (pMHC). It remains unclear how many TCR sequences are recruited into an antigen-specific T cell response, both within and across different organisms, and which factors shape both of these distributions. Infection of mice with ovalbumin-expressing cytomegalovirus (IE2-OVA-mCMV) represents a well-studied model system to investigate T cell responses given their size and longevity. Here we investigated > 180,000 H2kb/SIINFEKL-recognizing TCR CDR3α or CDR3β sequences from 25 individual mice spanning seven different time points during acute infection and memory inflation. In-depth repertoire analysis revealed that from a pool of highly diverse, but overall limited sequences, T cell responses were dominated by public clonotypes, partly with unexpectedly extreme degrees of sharedness between individual mice (“supra-public clonotypes”). Public clonotypes were found exclusively in a fraction of TCRs with a high generation probability. Generation probability and degree of sharedness select for highly functional TCRs, possibly mediated through elevating intraindividual precursor frequencies of clonotypes. Full article
(This article belongs to the Special Issue Cytomegalovirus (CMV) Infection and Latency)
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18 pages, 4623 KiB  
Article
Identification and Morphological Characterization of Biofilms Formed by Strains Causing Infection in Orthopedic Implants
by Débora C. Coraça-Huber, Lisa Kreidl, Stephan Steixner, Maximilian Hinz, Dietmar Dammerer and Manfred Fille
Pathogens 2020, 9(8), 649; https://doi.org/10.3390/pathogens9080649 - 12 Aug 2020
Cited by 13 | Viewed by 3397
Abstract
Objectives: For a better understanding of the mechanisms involved in biofilm formation, we performed a broad identification and characterization of the strains affecting implants by evaluating the morphology of biofilms formed in vitro in correlation with tests of the strains’ antibiotic susceptibility in [...] Read more.
Objectives: For a better understanding of the mechanisms involved in biofilm formation, we performed a broad identification and characterization of the strains affecting implants by evaluating the morphology of biofilms formed in vitro in correlation with tests of the strains’ antibiotic susceptibility in planktonic form. The ability of the strains to form biofilms in vitro was evaluated by means of colony forming units counting, metabolic activity tests of biofilm cells, and scanning electron microscopy. Methods: A total of 140 strains were isolated from patients with orthopedic implant-related infections during the period of 2015 to 2018. The identification of the isolates was carried out through microbiological cultures and confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiotic susceptibility rates of the isolates were accessed according to EUCAST (European Committee on Antimicrobial Susceptibility Testing). The ability of all isolates to form biofilms in vitro was evaluated by counting the colony forming units, by measuring the metabolic activity of biofilm cells, and by analyzing the morphology of the formed biofilms using scanning electron microscopy. Results: From all the isolates, 41.84% (62 strains) were Staphylococcus epidermidis and 15.60% (22 strains) were Staphylococcus aureus. A significant difference in the capacity of biofilm formation was observed among the isolates. When correlating the biofilm forming capacity of the isolates to their antibiotic susceptibility rates, we observed that not all strains that were classified as resistant were biofilm producers in vitro. In other words, bacteria that are not good biofilm formers can show increased tolerance to multiple antibiotic substances. Conclusion: From 2015 until 2018, Staphylococcus epidermidis was the strain that caused most of the orthopedic implant-related infections in our hospital. Not all strains causing infection in orthopedic implants are able to form biofilms under in vitro conditions. Differences were observed in the number of cells and morphology of the biofilms. In addition, antibiotic resistance is not directly related to the capacity of the strains to form biofilms in vitro. Further studies should consider the use of in vitro culture conditions that better reproduce the joint environment and the growth of biofilms in humans. Full article
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8 pages, 437 KiB  
Article
No-Touch Automated Room Disinfection after Autopsies of Exhumed Corpses
by Patryk Tarka, Aleksandra Borowska-Solonynko, Małgorzata Brzozowska, Aneta Nitsch-Osuch, Krzysztof Kanecki, Robert Kuthan and Barbara Garczewska
Pathogens 2020, 9(8), 648; https://doi.org/10.3390/pathogens9080648 - 12 Aug 2020
Cited by 3 | Viewed by 2435
Abstract
Autopsies of exhumed bodies pose a risk of infections with environmental bacteria or fungi, which may be life-threatening. Thus, it is important to use effective methods of disinfection in forensic pathology facilities. In this study, we investigated the effectiveness of no-touch automated disinfection [...] Read more.
Autopsies of exhumed bodies pose a risk of infections with environmental bacteria or fungi, which may be life-threatening. Thus, it is important to use effective methods of disinfection in forensic pathology facilities. In this study, we investigated the effectiveness of no-touch automated disinfection (NTD) system after autopsies of exhumed bodies. Directly after 11 autopsies of exhumed bodies, we used an NTD system based on a peroxone vapor to disinfect the air and surfaces. We measured microbial burden in the air and on surfaces before and after NTD. The NTD system reduced the mean bacterial burden in the air from 171 colony forming units (CFU)/m3 to 3CFU/m3. The mean fungal burden in the air decreased from 221 CFU/m3 to 9CFU/m3. The mean all-surface microbial burden was 79 CFU/100 cm2 after all autopsies, and it decreased to 2 CFU/100 cm2 after NTD. In conclusion, the peroxone-based NTD system was effective for decontamination of the air and surfaces in a dissecting room after autopsies of exhumed bodies. Full article
(This article belongs to the Section Human Pathogens)
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3 pages, 194 KiB  
Editorial
Neisseria gonorrhoeae Infections
by Beatriz Suay-García and María-Teresa Pérez-Gracia
Pathogens 2020, 9(8), 647; https://doi.org/10.3390/pathogens9080647 - 12 Aug 2020
Cited by 1 | Viewed by 3336
Abstract
Gonorrhea is a sexually transmitted disease with a high morbidity burden. Despite having guidelines for its treatment, the incidence of the disease follows an increasing trend worldwide. This is mainly due to the appearance of antibiotic-resistant strains, inefficient diagnostic methods and poor sexual [...] Read more.
Gonorrhea is a sexually transmitted disease with a high morbidity burden. Despite having guidelines for its treatment, the incidence of the disease follows an increasing trend worldwide. This is mainly due to the appearance of antibiotic-resistant strains, inefficient diagnostic methods and poor sexual education. Without an effective vaccine available, the key priorities for the control of the disease include sexual education, contact notification, epidemiological surveillance, diagnosis and effective antibiotic treatment. This Special Issue focuses on some of these important issues such as the molecular mechanisms of the disease, diagnostic tests and different treatment strategies to combat gonorrhea. Full article
(This article belongs to the Special Issue Neisseria gonorrhoeae Infections)
13 pages, 1792 KiB  
Communication
Effect of Ethanol Extracts of Propolis (EEPs) against Staphylococcal Biofilm—Microscopic Studies
by Katarzyna Grecka, Zirui Ray Xiong, Hanyu Chen, Karolina Pełka, Randy W. Worobo and Piotr Szweda
Pathogens 2020, 9(8), 646; https://doi.org/10.3390/pathogens9080646 - 11 Aug 2020
Cited by 12 | Viewed by 3608
Abstract
Staphylococci growing in the form of biofilm exhibit high resistance to a plethora of antibiotics. The aim of the study was to assess the influence of ethanolic extract of propolis (EEPs) on S. epidermidis ATCC 35984 biofilm using fluorescent microscopy. Propidium iodide (PI) [...] Read more.
Staphylococci growing in the form of biofilm exhibit high resistance to a plethora of antibiotics. The aim of the study was to assess the influence of ethanolic extract of propolis (EEPs) on S. epidermidis ATCC 35984 biofilm using fluorescent microscopy. Propidium iodide (PI) and SYTO 9 were used for differentiation of live and dead cells, and calcofluor white was used to stain the extracellular matrix, the self-produced extracellular polymeric substances (EPS). The outcomes of the research confirm the promising potential of EEPs for eradication of staphylococcal biofilm. However, its activity cannot be classified as fully satisfactory, either in terms of the effectiveness of elimination of bacterial cells or disturbing the EPS structure. A two or even four times higher concentration of EEPs compared to MIC (Minimum Inhibitory Concentration) against planktonic cells (128 µg/mL) was necessary for effective (estimated for 90%) elimination of living cells from the biofilm structure. Unfortunately, even at that concentration of EEPs, the extracellular matrix was only partially disturbed and effectively protected the residual population of living cells of S. epidermidis ATCC 35984. In our opinion, a combination of EEPs with agents disrupting components of EPS, e.g., proteases, lysines, or enzymes degrading extracellular DNA or PIA (polysaccharide intercellular adhesin). Full article
(This article belongs to the Section Human Pathogens)
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14 pages, 1757 KiB  
Article
Human Bocavirus in Brazil: Molecular Epidemiology, Viral Load and Co-Infections
by Fábio Correia Malta, Rafael Brandão Varella, Maria Angelica Arpon Marandino Guimarães, Marize Pereira Miagostovich and Tulio Machado Fumian
Pathogens 2020, 9(8), 645; https://doi.org/10.3390/pathogens9080645 - 10 Aug 2020
Cited by 11 | Viewed by 2805
Abstract
Human bocavirus (HBoV) is an emerging virus and has been detected worldwide, especially in pediatric patients with respiratory and gastrointestinal infection. In this study, we describe HBoV prevalence, genotypes circulation and DNA shedding, in stool samples from children up to two years of [...] Read more.
Human bocavirus (HBoV) is an emerging virus and has been detected worldwide, especially in pediatric patients with respiratory and gastrointestinal infection. In this study, we describe HBoV prevalence, genotypes circulation and DNA shedding, in stool samples from children up to two years of age in Brazil. During 2016 and 2017, 886 acute gastroenteritis (AGE) stool samples from ten Brazilian states were analyzed by TaqMan®-based qPCR, to detect and quantify HBoV. Positive samples were genotyped by sequencing the VP1/2 overlap region, followed by phylogenetic analysis and co-infections were accessed by screening other gastroenteric viruses. HBoV was detected in 12.4% (n = 110) of samples, with viral load ranging from 1.6 × 102 to 1.2 × 109 genome copies per gram of stool. From these, co-infections were found in 79.1%, and a statistically lower HBoV viral load was found compared to viral loads of rotavirus, norovirus and adenovirus in double infected patients (p < 0.05). No significant differences were found between HBoV viral load in single or co-infections, age groups or genotypes. Phylogenetic analysis identified the circulation of HBoV-1 in 38%, HBoV-2 in 40% and HBoV-3 in 22%. Continuous HBoV monitoring is needed to clarify its role in diarrhea disease, especially in the absence of classic gastroenteric viruses. Full article
(This article belongs to the Section Human Pathogens)
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21 pages, 3464 KiB  
Article
Analyses of the Root-Knot Nematode (Meloidogyne graminicola) Transcriptome during Host Infection Highlight Specific Gene Expression Profiling in Resistant Rice Plants
by Anne-Sophie Petitot, Alexis Dereeper, Corinne Da Silva, Julie Guy and Diana Fernandez
Pathogens 2020, 9(8), 644; https://doi.org/10.3390/pathogens9080644 - 08 Aug 2020
Cited by 16 | Viewed by 4008
Abstract
The plant-parasitic nematode Meloidogyne graminicola causes considerable damages to rice (Oryza sativa) culture. Resistance to M. graminicola in the related species Oryza glaberrima reduces root penetration by juveniles and stops further nematode development. M. graminicola genes expressed during O. sativa infection [...] Read more.
The plant-parasitic nematode Meloidogyne graminicola causes considerable damages to rice (Oryza sativa) culture. Resistance to M. graminicola in the related species Oryza glaberrima reduces root penetration by juveniles and stops further nematode development. M. graminicola genes expressed during O. sativa infection were previously characterized but no information is available about the molecular dialogue established with a resistant plant. We compared the M. graminicola transcriptomes of stage-two juveniles (J2s) before and during infection of susceptible or resistant rice. Among 36,121 M. graminicola genes surveyed, 367 were differentially expressed during infection of resistant or susceptible plants. Genes encoding cell wall-degrading enzymes, peptidases and neuropeptides were expressed for a longer time in resistant plants compared to susceptible plants. Conversely, genes related to nematode development were not activated in the resistant host. The majority of M. graminicola effector genes had similar expression patterns, whatever the host genotype. However, two venom allergen-like protein (VAP)-encoding genes were specifically induced in resistant plants and Mg-VAP1 silencing in J2s reduced their ability to colonize roots. This study highlighted that M. graminicola adapts its gene expression to the host susceptibility. Further investigation is required to assess the role of Mg-VAPs in the rice–nematode interaction. Full article
(This article belongs to the Section Plant Pathogens)
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22 pages, 1732 KiB  
Article
Antimicrobial Resistance and Biofilm Formation Capacity of Salmonella enterica Serovar Enteritidis Strains Isolated from Poultry and Humans in Poland
by Katarzyna Ćwiek, Kamila Korzekwa, Aleksandra Tabiś, Jacek Bania, Gabriela Bugla-Płoskońska and Alina Wieliczko
Pathogens 2020, 9(8), 643; https://doi.org/10.3390/pathogens9080643 - 07 Aug 2020
Cited by 21 | Viewed by 3407
Abstract
Salmonella enterica ser. Enteritidis (S. enterica ser. Enteritidis) is the most frequently detected serovar in human salmonellosis, and its ability to produce a biofilm and the risk of transmission from animals and food of animal origin to humans are significant. The main [...] Read more.
Salmonella enterica ser. Enteritidis (S. enterica ser. Enteritidis) is the most frequently detected serovar in human salmonellosis, and its ability to produce a biofilm and the risk of transmission from animals and food of animal origin to humans are significant. The main aim of the present work was to compare S. enterica ser. Enteritidis strains isolated from poultry and human feces in terms of resistance profiles, prevalence of selected resistance genes, and their potential for biofilm formation, by assessing their biofilm growth intensity, the prevalence and expression of selected genes associated with this phenomenon, and the correlation between increased antimicrobial resistance and biofilm formation ability of the two tested groups of S. enterica ser. Enteritidis. This study showed a difference in antimicrobial resistance (minimal inhibitory concentration value) between S. enterica ser. Enteritidis groups; however, the majority of multidrug-resistant (MDR) strains were isolated from poultry (environmental samples from chicken broilers, turkey broilers, and laying hens). Differences in the prevalence of resistance genes were observed; the most common gene among poultry strains was floR, and that among strains from humans was blaTEM. S. enterica ser. Enteritidis strains isolated from poultry under the tested incubation conditions exhibited better biofilm growth than strains isolated from humans. A higher level of gene expression associated with the production of cellulose was only detected in the S48 strain isolated from poultry. On the other hand, increased expression of genes associated with quorum sensing was observed in two strains isolated from poultry farms and one strain isolated from human feces. Full article
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13 pages, 1992 KiB  
Article
Development and Validation of a New TaqMan Real-Time PCR for Detection of ‘Candidatus Phytoplasma pruni’
by Zala Kogej, Marina Dermastia and Nataša Mehle
Pathogens 2020, 9(8), 642; https://doi.org/10.3390/pathogens9080642 - 07 Aug 2020
Cited by 10 | Viewed by 3784
Abstract
Phytoplasmas of the 16SrIII group are wide spread, and have a broad plant host range. Among these, ‘Candidatus phytoplasma pruni’ (‘Ca. P. pruni’; phytoplasmas of 16SrIII subgroup A) can cause serious diseases in Prunus species and ‘Ca. P. pruni’-related strains [...] Read more.
Phytoplasmas of the 16SrIII group are wide spread, and have a broad plant host range. Among these, ‘Candidatus phytoplasma pruni’ (‘Ca. P. pruni’; phytoplasmas of 16SrIII subgroup A) can cause serious diseases in Prunus species and ‘Ca. P. pruni’-related strains can infect other plant species, including grapevines. In this study, a new real-time PCR detection system was developed for ‘Ca. P. pruni’ using TaqMan chemistry. This test was designed to detect ‘Ca. P. pruni’, by amplifying the species-specific secY gene. In addition, a test to amplify the group-specific 16S rRNA gene region was also developed. The performances of both tests were evaluated. The test that amplifies the secY gene provided reliable and quick detection of ‘Ca. P. pruni’. Using the newly developed and validated test, ‘Ca. P. pruni’ was not found in any of the 434 field samples collected from different plants species grown in different regions of Slovenia. Full article
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24 pages, 432 KiB  
Review
Preclinical Models of Nontuberculous Mycobacteria Infection for Early Drug Discovery and Vaccine Research
by Elisa Rampacci, Valentina Stefanetti, Fabrizio Passamonti and Marcela Henao-Tamayo
Pathogens 2020, 9(8), 641; https://doi.org/10.3390/pathogens9080641 - 06 Aug 2020
Cited by 14 | Viewed by 4136
Abstract
Nontuberculous mycobacteria (NTM) represent an increasingly prevalent etiology of soft tissue infections in animals and humans. NTM are widely distributed in the environment and while, for the most part, they behave as saprophytic organisms, in certain situations, they can be pathogenic, so much [...] Read more.
Nontuberculous mycobacteria (NTM) represent an increasingly prevalent etiology of soft tissue infections in animals and humans. NTM are widely distributed in the environment and while, for the most part, they behave as saprophytic organisms, in certain situations, they can be pathogenic, so much so that the incidence of NTM infections has surpassed that of Mycobacterium tuberculosis in developed countries. As a result, a growing body of the literature has focused attention on the critical role that drug susceptibility tests and infection models play in the design of appropriate therapeutic strategies against NTM diseases. This paper is an overview of the in vitro and in vivo models of NTM infection employed in the preclinical phase for early drug discovery and vaccine development. It summarizes alternative methods, not fully explored, for the characterization of anti-mycobacterial compounds. Full article
(This article belongs to the Section Vaccines and Therapeutic Developments)
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