Pathogens

11 pages, 1257 KiB

Open AccessFeature PaperArticle

PrPSc with Seeding Activity Extensively Overlaps with Proteinase-Resistant PrPSc Rather than Infectious PrPSc

by Yoshifumi Iwamaru, Yuichi Matsuura and Kohtaro Miyazawa

Pathogens 2020, 9(3), 241; https://doi.org/10.3390/pathogens9030241 - 24 Mar 2020

Cited by 3 | Viewed by 3775

The disease-associated prion protein (PrPSc) has the ability to seed the conformational conversion of normal prion proteins into the amyloid fibril form. This prion seeding activity can be measured using an in vitro amplification assay termed real-time quaking-induced conversion (RT-QuIC). There is a [...] Read more.

The disease-associated prion protein (PrPSc) has the ability to seed the conformational conversion of normal prion proteins into the amyloid fibril form. This prion seeding activity can be measured using an in vitro amplification assay termed real-time quaking-induced conversion (RT-QuIC). There is a strong correlation between RT-QuIC positivity and prion infection; however, the relationship between seeding activity and infectivity remains elusive. In this study, we used endpoint dilution RT-QuIC on the brain homogenates from wild-type mice with mouse-adopted bovine spongiform encephalopathy (mBSE) at defined intervals during the incubation period and evaluated the temporal relationship among prion seeding dose, levels of proteinase-resistant PrPSc (PrPres), and infectious titer. We found that the infectious titer reached a plateau by 100 days postinfection, whereas seeding dose and PrPres levels were continuously elevated. Our calculation showed that the doubling time (dt) for seeding dose from 40 to 100 days postinoculation was closer to the dt for PrPres levels than to the dt for prion titer. Although an uncoupling of seeding doses and PrPres levels was observed at end-stage disease in this model, our findings suggest that there is substantial but not complete overlap between PrPSc with seeding activity and PrPres rather than infectious PrPSc. Full article

(This article belongs to the Special Issue Prions and Prion-Like Transmissible Protein Pathogens)

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12 pages, 2796 KiB

Open AccessEditor’s ChoiceArticle

Evolutionary Trajectory for the Emergence of Novel Coronavirus SARS-CoV-2

by Saif ur Rehman, Laiba Shafique, Awais Ihsan and Qingyou Liu

Pathogens 2020, 9(3), 240; https://doi.org/10.3390/pathogens9030240 - 23 Mar 2020

Cited by 149 | Viewed by 26373

Abstract

Over the last two decades, the world experienced three outbreaks of coronaviruses with elevated morbidity rates. Currently, the global community is facing emerging virus SARS-CoV-2 belonging to Betacoronavirus, which appears to be more transmissible but less deadly than SARS-CoV. The current study [...] Read more.

Over the last two decades, the world experienced three outbreaks of coronaviruses with elevated morbidity rates. Currently, the global community is facing emerging virus SARS-CoV-2 belonging to Betacoronavirus, which appears to be more transmissible but less deadly than SARS-CoV. The current study aimed to track the evolutionary ancestors and different evolutionary strategies that were genetically adapted by SARS-CoV-2. Our whole-genome analysis revealed that SARS-CoV-2 was the descendant of Bat SARS/SARS-like CoVs and bats served as a natural reservoir. SARS-CoV-2 used mutations and recombination as crucial strategies in different genomic regions including the envelop, membrane, nucleocapsid, and spike glycoproteins to become a novel infectious agent. We confirmed that mutations in different genomic regions of SARS-CoV-2 have specific influence on virus reproductive adaptability, allowing for genotype adjustment and adaptations in rapidly changing environments. Moreover, for the first time we identified nine putative recombination patterns in SARS-CoV-2, which encompass spike glycoprotein, RdRp, helicase and ORF3a. Six recombination regions were spotted in the S gene and are undoubtedly important for evolutionary survival, meanwhile this permitted the virus to modify superficial antigenicity to find a way from immune reconnaissance in animals and adapt to a human host. With these combined natural selected strategies, SARS-CoV-2 emerged as a novel virus in human society. Full article

(This article belongs to the Section Animal Pathogens)

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18 pages, 13008 KiB

Open AccessArticle

Human Papillomavirus E6/E7 Expression in Preeclampsia-Affected Placentae

by Ashley L. Reily-Bell, Amanda Fisher, Bryony Harrison, Sara Bowie, Sankalita Ray, Mary Hawkes, Lyn M. Wise, Ryuji Fukuzawa, Erin C. Macaulay, Celia J. Devenish, Noelyn A. Hung and Tania L. Slatter

Pathogens 2020, 9(3), 239; https://doi.org/10.3390/pathogens9030239 - 23 Mar 2020

Cited by 1 | Viewed by 3283

Abstract

Whether HPV is causative of pregnancy complications is uncertain. E6 and E7 affect functions underling preeclampsia (PET) in cultured trophoblasts, but whether E6 and E7 is produced in the placenta is uncertain. Here, we investigated whether E6/E7 was expressed in the [...] Read more.

Whether HPV is causative of pregnancy complications is uncertain. E6 and E7 affect functions underling preeclampsia (PET) in cultured trophoblasts, but whether E6 and E7 is produced in the placenta is uncertain. Here, we investigated whether E6/E7 was expressed in the placentae from pregnancies with PET, other pregnancy complications (fetal growth restriction (FGR) and diabetes mellitus), and uncomplicated pregnancies. Placental tissues collected from two geographical locations were subjected to RNAscope analyses of high- and low- risk E6/E7, and individual HPV types identified using an HPV array. High-risk E6/E7 expression was increased in both PET cohorts, (81% and 86% of patients positive for high-risk HPV DNA compared to 13% of control patients). Various HPV types were identified. Although HPV 18 was the most frequent in all cohorts, the majority of individuals had multiple HPV types (55% of the PET compared to 25% of the control cohort). Further evidence that E6 and E7 is present early when placental pathology underlying preeclampsia is established, is provided with the finding of high-risk E6/E7 in the first-trimester placenta anchoring trophoblast. In conclusion, E6/E7 expression and multiple HPV types were frequent in placentae from preeclampsia-complicated pregnancies. Full article

(This article belongs to the Section Human Pathogens)

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15 pages, 2564 KiB

Open AccessArticle

Molecular Typing, Antibiogram and PCR-RFLP Based Detection of Aeromonas hydrophila Complex Isolated from Oreochromis niloticus

by Abdelazeem M. Algammal, Mohamed Fathi Mohamed, Basma A. Tawfiek, Wael N. Hozzein, Waleed M. El Kazzaz and Mahmoud Mabrok

Pathogens 2020, 9(3), 238; https://doi.org/10.3390/pathogens9030238 - 22 Mar 2020

Cited by 68 | Viewed by 6267

Abstract

Motile Aeromonas septicemia is a common bacterial disease that affects Oreochromis niloticus and causes tremendous economic losses globally. In order to investigate the prevalence, molecular typing, antibiogram and the biodiversity of Aeromonas hydrophila complex, a total of 250 tilapia (Oreochromis niloticus) [...] Read more.

Motile Aeromonas septicemia is a common bacterial disease that affects Oreochromis niloticus and causes tremendous economic losses globally. In order to investigate the prevalence, molecular typing, antibiogram and the biodiversity of Aeromonas hydrophila complex, a total of 250 tilapia (Oreochromis niloticus) were collected randomly from 10 private tilapia farms (25 fish/farm) at El-Sharkia Governorate, Egypt. The collected fish were subjected to clinical and bacteriological examinations. The majority of infected fish displayed ulcerative necrosis, exophthalmia, and internal signs of hemorrhagic septicemia. The prevalence of A. hydrophia complex was 13.2%, where the liver was the most predominant affected organ (54.1%). Polymerase chain reaction (PCR) was used to verify the identification of A. hydrophila complex using one set of primers targeting gyrB as well as the detection of virulent genes (aerA, alt, and ahp). All isolates were positive for the gyrB-conserved gene and harbored aerA and alt virulence genes. However, none of those isolates were positive for the ahp gene. The antimicrobial sensitivity was carried out, where the recovered strains were completely sensitive to ciprofloxacin and highly resistant to amoxicillin. All retrieved strains showed the same phenotypic characteristics and were identical based on the restriction fragment length polymorphism (RFLP). Experimentally challenged fish presented a high mortality rate (76.67%) and showed typical signs as in naturally infected ones. In conclusion, the synergism of phenotypic and genotypic characterization is a valuable epidemiological tool for the diagnosis of A. hydrophila complex. RFLP is a fundamental tool for monitoring the biodiversity among all retrieved strains of A. hydrophia. Full article

(This article belongs to the Special Issue Animal Parasitic Diseases)

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11 pages, 3111 KiB

Open AccessArticle

Analysis of the Clinical Course of Experimental Infection with Highly Pathogenic African Swine Fever Strain, Isolated from an Outbreak in Poland. Aspects Related to the Disease Suspicion at the Farm Level

by Marek Walczak, Jacek Żmudzki, Natalia Mazur-Panasiuk, Małgorzata Juszkiewicz and Grzegorz Woźniakowski

Pathogens 2020, 9(3), 237; https://doi.org/10.3390/pathogens9030237 - 22 Mar 2020

Cited by 26 | Viewed by 4595

Abstract

This paper was aimed to characterize clinical signs and pathomorphological lesions in twenty-two pigs, infected intranasally by different doses of African swine fever virus (Pol18_28298_O111), isolated during the outbreak in a pig farm that occurred in Eastern Poland throughout 2018. This article also [...] Read more.

This paper was aimed to characterize clinical signs and pathomorphological lesions in twenty-two pigs, infected intranasally by different doses of African swine fever virus (Pol18_28298_O111), isolated during the outbreak in a pig farm that occurred in Eastern Poland throughout 2018. This article also attempts to indicate risk, related to virus load and shedding, and present possible difficulties with proper disease recognition at the farm level. The results revealed that even a very low dose (5 HAU) may initiate the infection. Various forms of the disease (acute, subacute, and chronic), mainly with prodromal clinical signs like fever, apathy, and reduced feed intake were observed. The most frequently observed lesions (82%) were: hyperemia and enlargement of lymph nodes and splenomegaly. The minimal incubation period was estimated at five days post-infection (dpi). Mortality ranged from 80–100%. Two pigs survived the infection. Some viremic animals presented delayed fever. In some cases, the fever was not detectable. Shortly after viremia, the virus was secreted ion the urine, feces, and saliva. The highest levels of virus were found in the internal organs and blood; however in the case of one pig (chronic form), viral DNA was not detected in the spleen, liver, bone marrow, and brain. Veterinary diagnosis may be difficult, and the final results should always be based on laboratory investigations. Full article

(This article belongs to the Special Issue African Swine Fever Virus Infection)

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17 pages, 1920 KiB

Open AccessEditor’s ChoiceArticle

Impact of Environmental Conditions and Agronomic Practices on the Prevalence of Fusarium Species Associated with Ear- and Stalk Rot in Maize

by Annette Pfordt, Lucia Ramos Romero, Simon Schiwek, Petr Karlovsky and Andreas von Tiedemann

Pathogens 2020, 9(3), 236; https://doi.org/10.3390/pathogens9030236 - 21 Mar 2020

Cited by 52 | Viewed by 5864

Abstract

Fusarium species are common pathogens on maize and reduce the product quality through contamination with mycotoxins thus jeopardizing safety of both animal feed and human food products. Monitoring of Fusarium infected maize ears and stalks was conducted in Germany to determine the range [...] Read more.

Fusarium species are common pathogens on maize and reduce the product quality through contamination with mycotoxins thus jeopardizing safety of both animal feed and human food products. Monitoring of Fusarium infected maize ears and stalks was conducted in Germany to determine the range of Fusarium species present in the field and to assess the impact of tillage, crop rotation, and weather conditions on the frequency of Fusarium species. From 2016 till 2018, a total of 387 infected ears and 190 stalk segments from 58 locations in Germany were collected. For each sample location, site-specific agronomic data on tillage and previous crops as well as meteorological data on precipitation, air temperature, and relative humidity during the vegetation period were recorded. The most frequent Fusarium species detected in maize ears were Fusarium graminearum, F. verticillioides and F. temperatum, whereas, F. graminearum, F. equiseti, F. culmorum, and F. temperatum were the species prevailing on maize stalks. Differences in the local species composition were found to be primarily associated with weather variations between the years and the microclimate at the different locations. The results indicate that mean temperature and precipitation in July, during flowering, has the strongest impact on the local range of Fusarium spp. on ears, whereas the incidence of Fusarium species on stalks is mostly affected by weather conditions during September. Ploughing significantly reduced the infection with F. graminearum and F. temperatum, while crop rotation exerted only minor effects. Full article

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12 pages, 747 KiB

Open AccessArticle

Response of Human Neutrophil Granulocytes to the Hyphae of the Emerging Fungal Pathogen Curvularia lunata

by Eszter Judit Tóth, Mónika Varga, Miklós Takó, Mónika Homa, Olivér Jáger, Edit Hermesz, Hajnalka Orvos, Gábor Nagy, Csaba Vágvölgyi and Tamás Papp

Pathogens 2020, 9(3), 235; https://doi.org/10.3390/pathogens9030235 - 21 Mar 2020

Cited by 9 | Viewed by 3127

Abstract

Curvularia lunata is an ascomycete filamentous fungus causing local and invasive phaeohyphomycoses in both immunocompromised and immunocompetent patients. Neutrophils are crucial participants of the first line host defense against fungal infections. They migrate to the infected site and eliminate the infectious agents by [...] Read more.

Curvularia lunata is an ascomycete filamentous fungus causing local and invasive phaeohyphomycoses in both immunocompromised and immunocompetent patients. Neutrophils are crucial participants of the first line host defense against fungal infections. They migrate to the infected site and eliminate the infectious agents by various mechanisms including phagocytoses, oxidative damage, or formation of neutrophil extracellular trap (NET). Neutropenia may be a risk factor for phaeohyphomycoses, and restoration of the neutrophil function can improve the outcome of the infection. In the present study, interaction of primary human neutrophil granulocytes with the hyphae C. lunata was examined and compared to that with the well characterized filamentous fungal pathogen Aspergillus fumigatus. Neutrophils could recognize the serum opsonized hyphae of C. lunata and attach to them. Myeloperoxidase release was also activated by a soluble factor present in the culture supernatant of the fungus. Induction of the oxidative burst was found to depend on serum opsonization of the hyphae. Although extracellular hydrogen peroxide production was induced, the fungus efficiently blocked the oxidative burst by acidifying the reaction environment. This blockage also affected the NET forming ability of the neutrophils. Full article

(This article belongs to the Section Human Pathogens)

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21 pages, 2582 KiB

Open AccessEditor’s ChoiceReview

The Bradyzoite: A Key Developmental Stage for the Persistence and Pathogenesis of Toxoplasmosis

by Aude Cerutti, Nicolas Blanchard and Sébastien Besteiro

Pathogens 2020, 9(3), 234; https://doi.org/10.3390/pathogens9030234 - 21 Mar 2020

Cited by 50 | Viewed by 13232

Abstract

Toxoplasma gondii is a ubiquitous parasitic protist found in a wide variety of hosts, including a large proportion of the human population. Beyond an acute phase which is generally self-limited in immunocompetent individuals, the ability of the parasite to persist as a dormant [...] Read more.

Toxoplasma gondii is a ubiquitous parasitic protist found in a wide variety of hosts, including a large proportion of the human population. Beyond an acute phase which is generally self-limited in immunocompetent individuals, the ability of the parasite to persist as a dormant stage, called bradyzoite, is an important aspect of toxoplasmosis. Not only is this stage not eliminated by current treatments, but it can also reactivate in immunocompromised hosts, leading to a potentially fatal outcome. Yet, despite its critical role in the pathology, the bradyzoite stage is relatively understudied. One main explanation is that it is a considerably challenging model, which essentially has to be derived from in vivo sources. However, recent progress on genetic manipulation and in vitro differentiation models now offers interesting perspectives for tackling key biological questions related to this particularly important developmental stage. Full article

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10 pages, 1130 KiB

Open AccessEditor’s ChoiceArticle

Characterization of the Humoral Immune Response to Porcine Epidemic Diarrhea Virus Infection under Experimental and Field Conditions Using an AlphaLISA Platform

by Kay Kimpston-Burkgren, Juan Carlos Mora-Díaz, Philippe Roby, Jordan Bjustrom-Kraft, Rodger Main, Roger Bosse and Luis Gabriel Giménez-Lirola

Pathogens 2020, 9(3), 233; https://doi.org/10.3390/pathogens9030233 - 21 Mar 2020

Cited by 7 | Viewed by 3495

Abstract

Coronavirus infections are a continuous threat raised time and again. With the recent emergence of novel virulent strains, these viruses can have a large impact on human and animal health. Porcine epidemic diarrhea (PED) is considered to be a reemerging pig disease caused [...] Read more.

Coronavirus infections are a continuous threat raised time and again. With the recent emergence of novel virulent strains, these viruses can have a large impact on human and animal health. Porcine epidemic diarrhea (PED) is considered to be a reemerging pig disease caused by the enteropathogenic alphacoronavirus PED virus (PEDV). In the absence of effective vaccines, infection prevention and control through diagnostic testing and quarantine are critical. Early detection and differential diagnosis of PEDV infections increase the chance of successful control of the disease. Therefore, there is a continuous need for development of reduced assay-step protocols, no-wash, high-throughput immunoassays. This study described the characterization of the humoral immune response against PEDV under experimental and field conditions using a rapid, sensitive, luminescent proximity homogenous assay (AlphaLISA). PEDV IgG and IgA antibodies were developed toward the beginning of the second week of infection. PEDV IgG antibodies were detected for at least 16 weeks post-exposure. Remarkably, the serum IgA levels remained high and relatively stable throughout the study, lasting longer than the serum IgG response. Overall, AlphaLISA allows the detection and characterization of pathogen-specific antibodies with new speed, sensitivity, and simplicity of use. Particularly, the bridge assay constitutes a rapid diagnostic that substantially improves upon the “time to result” metric of currently available immunoassays. Full article

(This article belongs to the Special Issue Immune Response to Porcine Epidemic Diarrhea Virus)

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16 pages, 2748 KiB

Open AccessArticle

Genomic Features of Cladobotryum dendroides, Which Causes Cobweb Disease in Edible Mushrooms, and Identification of Genes Related to Pathogenicity and Mycoparasitism

by Rong Xu, Xiaochen Liu, Bing Peng, Peibin Liu, Zhuang Li, Yueting Dai and Shijun Xiao

Pathogens 2020, 9(3), 232; https://doi.org/10.3390/pathogens9030232 - 20 Mar 2020

Cited by 15 | Viewed by 3980

Abstract

Cladobotryum dendroides, which causes cobweb disease in edible mushrooms, is one of the major fungal pathogens. Our previous studies focused on the genetic and morphological characterization of this fungus, as well as its pathogenicity and the identification of appropriate fungicides. However, little [...] Read more.

Cladobotryum dendroides, which causes cobweb disease in edible mushrooms, is one of the major fungal pathogens. Our previous studies focused on the genetic and morphological characterization of this fungus, as well as its pathogenicity and the identification of appropriate fungicides. However, little is known about the genome characters, pathogenic genes, and molecular pathogenic mechanisms of C. dendroides. Herein, we reported a high-quality de novo genomic sequence of C. dendroides and compared it with closely-related fungi. The assembled C. dendroides genome was 36.69 Mb, consisting of eight contigs, with an N50 of 4.76 Mb. This genome was similar in size to that of C. protrusum, and shared highly conserved syntenic blocks and a few inversions with C. protrusum. Phylogenetic analysis revealed that, within the Hypocreaceae, Cladobotryum was closer to Mycogone than to Trichoderma, which is consistent with phenotypic evidence. A significant number of the predicted expanded gene families were strongly associated with pathogenicity, virulence, and adaptation. Our findings will be instrumental for the understanding of fungi–fungi interactions, and for exploring efficient management strategies to control cobweb disease. Full article

(This article belongs to the Special Issue Genomics, Molecular, Genetics, and Diversity of Plant Disease Resistance)

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14 pages, 3323 KiB

Open AccessEditor’s ChoiceReview

SARS-CoV-2 and Coronavirus Disease 2019: What We Know So Far

by Firas A. Rabi, Mazhar S. Al Zoubi, Ghena A. Kasasbeh, Dunia M. Salameh and Amjad D. Al-Nasser

Pathogens 2020, 9(3), 231; https://doi.org/10.3390/pathogens9030231 - 20 Mar 2020

Cited by 479 | Viewed by 141656

Abstract

In December 2019, a cluster of fatal pneumonia cases presented in Wuhan, China. They were caused by a previously unknown coronavirus. All patients had been associated with the Wuhan Wholefood market, where seafood and live animals are sold. The virus spread rapidly and [...] Read more.

In December 2019, a cluster of fatal pneumonia cases presented in Wuhan, China. They were caused by a previously unknown coronavirus. All patients had been associated with the Wuhan Wholefood market, where seafood and live animals are sold. The virus spread rapidly and public health authorities in China initiated a containment effort. However, by that time, travelers had carried the virus to many countries, sparking memories of the previous coronavirus epidemics, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), and causing widespread media attention and panic. Based on clinical criteria and available serological and molecular information, the new disease was called coronavirus disease of 2019 (COVID-19), and the novel coronavirus was called SARS Coronavirus-2 (SARS-CoV-2), emphasizing its close relationship to the 2002 SARS virus (SARS-CoV). The scientific community raced to uncover the origin of the virus, understand the pathogenesis of the disease, develop treatment options, define the risk factors, and work on vaccine development. Here we present a summary of current knowledge regarding the novel coronavirus and the disease it causes. Full article

(This article belongs to the Collection SARS-CoV Infections)

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19 pages, 4968 KiB

Open AccessArticle

Host-Parasite Interaction between Parasitic Cymothoid Ceratothoa oestroides and Its Host, Farmed European Sea Bass (Dicentrarchus labrax)

by Ivona Mladineo, Jerko Hrabar, Olja Vidjak, Ivana Bočina, Slavica Čolak, Pantelis Katharios, Maria Chiara Cascarano, Kleoniki Keklikoglou, Donatella Volpatti and Paola Beraldo

Pathogens 2020, 9(3), 230; https://doi.org/10.3390/pathogens9030230 - 20 Mar 2020

Cited by 13 | Viewed by 5183

Abstract

Parasitic isopod Ceratothoa oestroides (Cymothoidea, Isopoda) is a common and generalist buccal cavity-dweller in marine fish, recognised for its detrimental effect in fingerling and juvenile farmed European sea bass (Dicentrarchus labrax). Although distributed throughout the Mediterranean, the isopod provokes acute outbreaks [...] Read more.

Parasitic isopod Ceratothoa oestroides (Cymothoidea, Isopoda) is a common and generalist buccal cavity-dweller in marine fish, recognised for its detrimental effect in fingerling and juvenile farmed European sea bass (Dicentrarchus labrax). Although distributed throughout the Mediterranean, the isopod provokes acute outbreaks mainly limited to particular endemic areas in Croatia (Adriatic Sea) and Greece (Aegean Sea). While numerous studies have previously evidenced its gross effect on farmed fish (i.e. decreased condition index, slower growth rate, lethargy and mortality), details on the host-parasite interaction are still lacking. Therefore, using a multimethodological approach, we closely examined the structure and appearance of isopod body parts acting in the attachment and feeding (stereomicroscopy, scanning and transmission electron microscopy), and the extent of host tissues damage (histology, immunohistochemistry, micro-computational tomography) induced by parasitation. Interestingly, while hematophagous nature of the parasite has been previously postulated we found no unambiguous data to support this; we observed host tissues fragmentation and extensive hyperplasia at the parasitation site, and no structures indicative of heme detoxifying mechanisms in the parasite gut, or other traces of a blood meal. The bacterial biofilm covering C. oestroides mouthparts and pereopods suggests that the isopod may play a role in conveying secondary pathogens to the infected host, or alternatively, it serves the parasite in normal interaction with its environment. Full article

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18 pages, 1970 KiB

Open AccessArticle

Etiology and Symptoms of Maize Leaf Spot Caused by Bipolaris spp. in Sichuan, China

by Xiaofang Sun, Xiaobo Qi, Wei Wang, Xuan Liu, Henan Zhao, Cuiping Wu, Xiaoli Chang, Min Zhang, Huabao Chen and Guoshu Gong

Pathogens 2020, 9(3), 229; https://doi.org/10.3390/pathogens9030229 - 20 Mar 2020

Cited by 28 | Viewed by 9346

Abstract

Many species of the genus Bipolaris are important plant pathogens and often cause leaf spot, root rot, and seedling blight in an extremely wide range of hosts around the world. In recent years, maize leaf spot caused by Bipolaris species has frequently occurred [...] Read more.

Many species of the genus Bipolaris are important plant pathogens and often cause leaf spot, root rot, and seedling blight in an extremely wide range of hosts around the world. In recent years, maize leaf spot caused by Bipolaris species has frequently occurred with complex symptoms and is becoming increasingly serious in Sichuan Province of China. To investigate the population diversity of Bipolaris spp. and their corresponding symptoms in maize, 747 samples of maize leaf spot were collected from 132 sampling sites in 19 administrative districts of Sichuan Province from 2011 to 2018. Based on morphological characteristics, pathogenicity testing, and phylogenetic analysis of the rDNA internal transcribed spacer (ITS) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes, a total of 1186 Bipolaris isolates were identified as B. maydis, B. zeicola, B. cynodontis, B. oryzae, B. setariae, and B. saccharicola, among which B. maydis and B. zeicola were the dominant pathogenic species, accounting for 57.34% and 42.07% of the isolates, respectively. We found that B. zeicola isolates were mainly distributed in high altitude and cool mountainous areas, while B. maydis was more widely distributed in Sichuan Province. The typical symptoms caused by the Bipolaris species were clearly distinct in maize. The typical symptoms caused by B. maydis were elongated strip lesions, or fusiform, elliptical lesions, and those caused by B. zeicola were narrow linear lesions. Herein, B. saccharicola was first reported on maize and caused subrotund lesions. This study provides useful information for disease diagnosis and management for Bipolaris leaf spot in maize. Full article

(This article belongs to the Section Plant Pathogens)

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7 pages, 636 KiB

Open AccessBrief Report

Commensal Neisseria Are Shared between Sexual Partners: Implications for Gonococcal and Meningococcal Antimicrobial Resistance

by Christophe Van Dijck, Jolein G. E. Laumen, Sheeba S. Manoharan-Basil and Chris Kenyon

Pathogens 2020, 9(3), 228; https://doi.org/10.3390/pathogens9030228 - 19 Mar 2020

Cited by 6 | Viewed by 2677

Abstract

Antimicrobial resistance in pathogenic Neisseria parallels reduced antimicrobial susceptibility in commensal Neisseria in certain populations, like men who have sex with men (MSM). Although this reduced susceptibility can be a consequence of frequent antimicrobial exposure at the individual level, we hypothesized that commensal [...] Read more.

Antimicrobial resistance in pathogenic Neisseria parallels reduced antimicrobial susceptibility in commensal Neisseria in certain populations, like men who have sex with men (MSM). Although this reduced susceptibility can be a consequence of frequent antimicrobial exposure at the individual level, we hypothesized that commensal Neisseria are transmitted between sexual partners. We used data from a 2014 microbiome study in which saliva and tongue swabs were taken from 21 couples (42 individuals). Samples were analyzed using 16S rRNA gene sequencing. We compared intimate partners with unrelated individuals and found that the oral Neisseria communities of intimate partners were more similar than those of unrelated individuals (average Morisita–Horn dissimilarity index for saliva samples: 0.54 versus 0.71, respectively (p = 0.005); and for tongue swabs: 0.42 versus 0.63, respectively (p = 0.006)). This similarity presumably results from transmission of oral Neisseria through intimate kissing. This finding suggests that intensive gonorrhea screening in MSM may, via increased antimicrobial exposure, promote, rather than prevent, the emergence and spread of antimicrobial resistance in Neisseria. Non-antibiotic strategies such as vaccines and oral antiseptics could prove more sustainable options to reduce gonococcal prevalence. Full article

(This article belongs to the Special Issue Neisseria gonorrhoeae Infections)

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20 pages, 2856 KiB

Open AccessEditor’s ChoiceArticle

Compost Amendments Based on Vinegar Residue Promote Tomato Growth and Suppress Bacterial Wilt Caused by Ralstonia Solanacearum

by Mingming He, Mohammad Shah Jahan, Yu Wang, Jin Sun, Sheng Shu and Shirong Guo

Pathogens 2020, 9(3), 227; https://doi.org/10.3390/pathogens9030227 - 19 Mar 2020

Cited by 23 | Viewed by 4694

Abstract

Tomato bacterial wilt caused by Ralstonia solanacearum (RS) is one of the most devastating soil-borne diseases, and compost is to be considered as a resource-saving and environment-friendly measure to control the disease. Herein, a pot experiment was implemented to explore the effects of [...] Read more.

Tomato bacterial wilt caused by Ralstonia solanacearum (RS) is one of the most devastating soil-borne diseases, and compost is to be considered as a resource-saving and environment-friendly measure to control the disease. Herein, a pot experiment was implemented to explore the effects of vinegar residue matrix amendments on the growth performances of tomato seedlings and to examine the suppression ability against bacterial wilt under vinegar residue substrate (VRS), and peat substrate (Peat) with RS inoculation. The results revealed that VRS effectively suppressed the disease incidence of bacterial wilt, increased the number of bacteria and actinomycetes, decreased fungi populations, promoted soil microbial populations and microbial activities, enhanced the growths of tomato seedlings, and modulated defense mechanism. In addition, VRS efficiently inhibited the oxidative damage in RS inoculated leaves via the regulation of excess reactive oxide species (O₂^•− and H₂O₂) production, lessening of malondialdehyde (MDA) content, and causing less membrane injury; resulting in enhancements of antioxidants enzymes activities accompanying with modulating their encoding gene expression. The transcription levels of NPR1, PIN2, PR1b, ACO1, EDS1, PR1B, MAPK3, PIN2, and RRS1 were also modulated with the pathogens inoculated in tomato leaves both in VRS and Peat treatments, which indicated that systemic-acquired resistance possesses cross-talk between salicylic acid, jasmonic acid, and the ethylene-dependent signaling pathway. Besides, the RS inoculation significantly inhibited the growth of tomato seedlings, and all growth indices of plants grown in VRS were considerably higher than those produced in Peat. Taken together, VRS represents a new strategy to control tomato bacterial wilt through boosting the soil microbial populations and microbial activities. Furthermore, VRS promotes the plant immune response to provide a better growth environment for plants surviving in disease conditions. Full article

(This article belongs to the Special Issue Control of Plant Pathogenic Bacteria with the Lowest Environmental Impact)

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17 pages, 600 KiB

Open AccessReview

Recent Advances in Diagnostic Approaches for Epstein–Barr Virus

by Mai Abdel Haleem Abusalah, Siew Hua Gan, Mohammad A. I. Al-Hatamleh, Ahmad Adebayo Irekeola, Rafidah Hanim Shueb and Chan Yean Yean

Pathogens 2020, 9(3), 226; https://doi.org/10.3390/pathogens9030226 - 18 Mar 2020

Cited by 62 | Viewed by 14357

Abstract

Epstein–Barr virus (EBV) is the causative agent of many diseases including infectious mononucleosis (IM), and it is associated with different subtypes of lymphoma, sarcoma and carcinoma such as Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, nasopharyngeal carcinoma, and gastric carcinoma. With the advent of improved laboratory [...] Read more.

Epstein–Barr virus (EBV) is the causative agent of many diseases including infectious mononucleosis (IM), and it is associated with different subtypes of lymphoma, sarcoma and carcinoma such as Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, nasopharyngeal carcinoma, and gastric carcinoma. With the advent of improved laboratory tests for EBV, a timelier and accurate diagnosis could be made to aid better prognosis and effective treatment. For histopathological lesions, the in situ hybridization (ISH) of EBV-encoded RNA (EBER) in biopsy tissues remains the gold standard for detecting EBV. Methods such as the heterophile antibody test, immunofluorescence assays, enzyme immunoassays, Western blot, and polymerase chain reaction (PCR) are also employed in the detection of EBV in different types of samples. The determination of EBV viral load using PCR, however, is gaining more prominence in the diagnosis of EBV-associated diseases. Given the challenge of false positive/negative results that are sometimes experienced during the detection of EBV, variability in results from different laboratories, and the impact of factors such as sample type and the immunological status of patients from whom samples are collected, the need to critically examine these present methods is invaluable. This review thus presents current advances in the detection of EBV, detailing the advantages and disadvantages of the various techniques. In addition, fundamental virological concepts are highlighted to enhance the greater understanding, the proper application, and the interpretation of EBV tests. Full article

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9 pages, 1228 KiB

Open AccessReview

Complex Cell Type-Specific Roles of Autophagy in Liver Fibrosis and Cirrhosis

by Tzu-Min Hung, Chih-Chiang Hsiao, Chih-Wen Lin and Po-Huang Lee

Pathogens 2020, 9(3), 225; https://doi.org/10.3390/pathogens9030225 - 18 Mar 2020

Cited by 13 | Viewed by 9491

Abstract

The lysosomal degradation pathway, or autophagy, plays a fundamental role in cellular, tissue, and organismal homeostasis. A correlation between dysregulated autophagy and liver fibrosis (including end-stage disease, cirrhosis) is well-established. However, both the up and downregulation of autophagy have been implicated in fibrogenesis. [...] Read more.

The lysosomal degradation pathway, or autophagy, plays a fundamental role in cellular, tissue, and organismal homeostasis. A correlation between dysregulated autophagy and liver fibrosis (including end-stage disease, cirrhosis) is well-established. However, both the up and downregulation of autophagy have been implicated in fibrogenesis. For example, the inhibition of autophagy in hepatocytes and macrophages can enhance liver fibrosis, whereas autophagic activity in hepatic stellate cells and reactive ductular cells is permissive towards fibrogenesis. In this review, the contributions of specific cell types to liver fibrosis as well as the mechanisms underlying the effects of autophagy are summarized. In view of the functional effects of multiple cell types on the complex process of hepatic fibrogenesis, integrated approaches that consider the role of autophagy in each liver cell type should be a focus of future research. Full article

(This article belongs to the Section Immunological Responses and Immune Defense Mechanisms)

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10 pages, 588 KiB

Open AccessArticle

High Human Papillomavirus DNA loads in Inflammatory Middle Ear Diseases

by Nicola Malagutti, John Charles Rotondo, Luca Cerritelli, Claudio Melchiorri, Monica De Mattei, Rita Selvatici, Lucia Oton-Gonzalez, Francesco Stomeo, Manuela Mazzoli, Michela Borin, Beatrice Mores, Andrea Ciorba, Mauro Tognon, Stefano Pelucchi and Fernanda Martini

Pathogens 2020, 9(3), 224; https://doi.org/10.3390/pathogens9030224 - 18 Mar 2020

Cited by 25 | Viewed by 4617

Abstract

Background. Previous studies reported human papillomaviruses (HPVs) in middle ear tumors, whereas these viruses have been poorly investigated in chronic inflammatory middle ear diseases. We investigated HPVs in non-tumor middle ear diseases, including chronic otitis media (COM). Methods. COM specimens (n [...] Read more.

Background. Previous studies reported human papillomaviruses (HPVs) in middle ear tumors, whereas these viruses have been poorly investigated in chronic inflammatory middle ear diseases. We investigated HPVs in non-tumor middle ear diseases, including chronic otitis media (COM). Methods. COM specimens (n = 52), including chronic suppurative otitis media (CSOM) (n =38) and cholesteatoma (COMC) (n = 14), as well as normal middle ear (NME) specimens (n = 56) were analyzed. HPV sequences and DNA loads were analyzed by quantitative-PCR. HPV genotyping was performed by direct sequencing. Results. HPV DNA was detected in 23% (12/52) of COM and in 30.4% (17/56) of NME (p > 0.05). Specifically, HPV DNA sequences were found in 26.3% (10/38) of CSOM and in 14.3% (2/14) of COMC (p > 0.05). Interestingly, the HPV DNA load was higher in COMC (mean 7.47 copy/cell) than in CSOM (mean 1.02 copy/cell) and NME (mean 1.18 copy/cell) (P = 0.03 and P = 0.017 versus CSOM and NME, respectively). HPV16 and HPV18 were the main genotypes detected in COMC, CSOM and NME. Conclusions. These data suggest that HPV may infect the middle ear mucosa, whereas HPV-positive COMCs are associated with higher viral DNA loads as compared to NME. Full article

(This article belongs to the Section Human Pathogens)

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19 pages, 660 KiB

Open AccessReview

Molecular Diagnostics and Pathogenesis of Fungal Pathogens on Bast Fiber Crops

by Yi Cheng, Xiaoyu Tang, Chunsheng Gao, Zhimin Li, Jia Chen, Litao Guo, Tuhong Wang and Jianping Xu

Pathogens 2020, 9(3), 223; https://doi.org/10.3390/pathogens9030223 - 18 Mar 2020

Cited by 15 | Viewed by 4145

Abstract

Bast fibers and products derived from them are undergoing a resurgence in demand in the global market. However, fungal diseases have become an important factor limiting their yield and quality, causing devastating consequences for the production of bast fiber crops in many parts [...] Read more.

Bast fibers and products derived from them are undergoing a resurgence in demand in the global market. However, fungal diseases have become an important factor limiting their yield and quality, causing devastating consequences for the production of bast fiber crops in many parts of the world. Thus, there is a high demand for effective control and prevention strategies against fungal pathogens. Having rapid, specific, sensitive, and cost-effective tests that can be used for early and accurate diagnosis of disease agents is an essential step of such strategies. The objective of this study was to review the current status of research on molecular diagnosis of fungal pathogens on bast fiber crops. Our search of PubMed identified nearly 20 genera of fungal pathogens on bast fiber crops, among which the five most common genera were Colletotrichum, Pythium, Verticillium, Fusarium, and Golovinomyces. The gene regions that have been used for molecular identifications of these fungi include internal transcribed spacer (ITS), translation elongation factor 1-α (EF-1α), ß-tubulin, calmodulin (CAL), histone subunit 3 (H3), glyceraldehydes-3-phosphate dehydrogenase (GAPDH), etc. We summarize the molecular assays that have been used to identify these fungi and discuss potential areas of future development for fast, specific, and accurate diagnosis of fungal pathogens on bast fiber crops. Full article

(This article belongs to the Section Plant Pathogens)

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8 pages, 2076 KiB

Open AccessCase Report

Carp Edema Virus and Cyprinid Herpesvirus-3 Coinfection is Associated with Mass Mortality of Koi (Cyprinus carpio haematopterus) in the Republic of Korea

by Sang Wha Kim, Sib Sankar Giri, Sang Guen Kim, Jun Kwon, Woo Taek Oh and Se Chang Park

Pathogens 2020, 9(3), 222; https://doi.org/10.3390/pathogens9030222 - 17 Mar 2020

Cited by 13 | Viewed by 3706

Abstract

As koi and common carp gain importance in the Korean fish industry, the need for better diagnosis, prevention, and treatment of associated diseases has increased. In June 2019, the first known case of mass mortality involving cyprinid herpesvirus-3 (CyHV-3) and the second involving [...] Read more.

As koi and common carp gain importance in the Korean fish industry, the need for better diagnosis, prevention, and treatment of associated diseases has increased. In June 2019, the first known case of mass mortality involving cyprinid herpesvirus-3 (CyHV-3) and the second involving carp edema virus (CEV) occurred in a koi farm in Jeolla-do, Korea. Notably, the CEV exhibited a closer phylogenetic relationship with certain CEV strains originating from Poland, Germany, and India than with strains originating from China or Japan. Epidemiological studies and detailed surveillance and control for CEV and CyHV-3 are needed along with quarantine inspections. Full article

(This article belongs to the Special Issue Viral Diseases of Fish)

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14 pages, 4814 KiB

Open AccessEditor’s ChoiceArticle

Free to Circulate: An Update on the Epidemiological Dynamics of Porcine Circovirus 2 (PCV-2) in Italy Reveals the Role of Local Spreading, Wild Populations, and Foreign Countries

by Giovanni Franzo, Susanna Tinello, Laura Grassi, Claudia Maria Tucciarone, Matteo Legnardi, Mattia Cecchinato, Giorgia Dotto, Alessandra Mondin, Marco Martini, Daniela Pasotto, Maria Luisa Menandro and Michele Drigo

Pathogens 2020, 9(3), 221; https://doi.org/10.3390/pathogens9030221 - 17 Mar 2020

Cited by 19 | Viewed by 3140

Abstract

Porcine circovirus 2 (PCV-2) is one of the most impactful and widespread pathogens of the modern swine industry. Unlike other DNA viruses, PCV-2 is featured by a remarkable genetic variability, which has led to the emergence and recognition of different genotypes, some of [...] Read more.

Porcine circovirus 2 (PCV-2) is one of the most impactful and widespread pathogens of the modern swine industry. Unlike other DNA viruses, PCV-2 is featured by a remarkable genetic variability, which has led to the emergence and recognition of different genotypes, some of which (PCV-2a, 2b, and 2d) have alternated over time. Currently, PCV-2d is considered the most prevalent genotype, and some evidence of differential virulence and vaccine efficacy have been reported. Despite the potential practical relevance, the data on PCV-2 epidemiology in Italy are quite outdated and do not quantify the actual circulation of this genotype in Italy. In the present study, 82 complete ORF2 sequences were obtained from domestic pigs and wild boars sampled in Northern Italy in the period 2013–2018 and merged with those previously obtained from Italy and other countries. A combination of phylogenetic, haplotype network, and phylodynamic analyses were used to genotype the collected strains and evaluate the temporal trend and the spatial and host spread dynamics. A rising number of PCV-2d detections was observed in domestic pigs, particularly since 2013, reaching a detection frequency comparable to PCV-2b. A similar picture was observed in wild boars, although a lower sequence number was available. Overall, the present study demonstrates the extreme complexity of PCV-2 molecular epidemiology in Italy, the significant spread across different regions, the recurrent introduction from foreign countries, and the frequent occurrence of recombination events. Although a higher viral flux occurred from domestic to wild populations than vice versa, wild boars seem to maintain PCV-2 infection and spread it over relatively long distances. Full article

(This article belongs to the Special Issue Porcine Circovirus Infections)

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2 pages, 170 KiB

Open AccessEditorial

Influenza Virus and Vaccination

by Aitor Nogales and Marta L. DeDiego

Pathogens 2020, 9(3), 220; https://doi.org/10.3390/pathogens9030220 - 17 Mar 2020

Cited by 5 | Viewed by 2539

Abstract

Influenza virus infections represent a serious public health problem causing contagious respiratory disease and substantial morbidity and mortality in humans, resulting in a considerable economic burden worldwide. Notably, the number of deaths due to influenza exceeds that of any other known pathogen. Moreover, [...] Read more.

Influenza virus infections represent a serious public health problem causing contagious respiratory disease and substantial morbidity and mortality in humans, resulting in a considerable economic burden worldwide. Notably, the number of deaths due to influenza exceeds that of any other known pathogen. Moreover, influenza infections can differ in their intensity, from mild respiratory disease to pneumonia, which can lead to death. Articles in this Special Issue have addressed different aspects of influenza in human health, and the advances in influenza research leading to the development of better therapeutics and vaccination strategies, with a special focus on the study of factors associated with innate or adaptive immune responses to influenza vaccination and/or infection. Full article

(This article belongs to the Special Issue Influenza Virus and Vaccination)

11 pages, 1668 KiB

Open AccessArticle

Combined Amoebicidal Effect of Atorvastatin and Commercial Eye Drops against Acanthamoeba castellanii Neff: In Vitro Assay Based on Mixture Design

by Ines Sifaoui, Eulalia Capote Yanes, María Reyes-Batlle, Rubén L. Rodríguez-Expósito, José E. Piñero and Jacob Lorenzo-Morales

Pathogens 2020, 9(3), 219; https://doi.org/10.3390/pathogens9030219 - 17 Mar 2020

Cited by 6 | Viewed by 2349

Abstract

The establishment of an effective therapeutic agent against Acanthamoeba keratitis (AK), remains until present, an issue to be solved due to the existence of a cyst stage in the life cycle of Acanthamoeba. Moreover, the effectiveness of the current standard therapeutic agents [...] Read more.

The establishment of an effective therapeutic agent against Acanthamoeba keratitis (AK), remains until present, an issue to be solved due to the existence of a cyst stage in the life cycle of Acanthamoeba. Moreover, the effectiveness of the current standard therapeutic agents varies depending on the tested Acanthamoeba strains and its resistance pattern. In the present study, two 10-point augmented simplex-centroid designs were used to formulate a three-component mixture system using water, atorvastatin, and Diclofenaco-lepori or Optiben. The amoebicidal effects and in vitro-induced toxicity in a eukaryotic cell line were determined for all experiments. The optimal mixture to inhibit the parasite without inducing toxicity was established in the first plan as 30% Optiben, 63.5% atorvastatin, and 3.1% water. As for the second experimental design, the optimal mixture to inhibit Acanthamoeba with lower toxicity effect was composed of 17.6% Diclofenaco-lepori and 82.4% atorvastatin. Full article

(This article belongs to the Special Issue Selected Papers from the International Meeting on the Biology and Pathogenicity of Free-Living Amoebae (FLAM2019))

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11 pages, 738 KiB

Open AccessReview

Intelligent Mechanisms of Macrophage Apoptosis Subversion by Mycobacterium

by Abualgasim Elgaili Abdalla, Hasan Ejaz, Mahjoob Osman Mahjoob, Ayman Ali Mohammed Alameen, Khalid Omer Abdalla Abosalif, Mohammed Yagoub Mohammed Elamir and Mohammed Alsadig Mousa

Pathogens 2020, 9(3), 218; https://doi.org/10.3390/pathogens9030218 - 16 Mar 2020

Cited by 12 | Viewed by 5566

Abstract

Macrophages are one of the first innate defense barriers and play an indispensable role in communication between innate and adaptive immune responses, leading to restricted Mycobacterium tuberculosis (Mtb) infection. The macrophages can undergo programmed cell death (apoptosis), which is a crucial [...] Read more.

Macrophages are one of the first innate defense barriers and play an indispensable role in communication between innate and adaptive immune responses, leading to restricted Mycobacterium tuberculosis (Mtb) infection. The macrophages can undergo programmed cell death (apoptosis), which is a crucial step to limit the intracellular growth of bacilli by liberating them into extracellular milieu in the form of apoptotic bodies. These bodies can be taken up by the macrophages for the further degradation of bacilli or by the dendritic cells, thereby leading to the activation of T lymphocytes. However, Mtb has the ability to interplay with complex signaling networks to subvert macrophage apoptosis. Here, we describe the intelligent strategies of Mtb inhibition of macrophages apoptosis. This review provides a platform for the future study of unrevealed Mtb anti-apoptotic mechanisms and the design of therapeutic interventions. Full article

(This article belongs to the Special Issue Mycobacterium tuberculosis Pathogenesis, Infection Prevention and Treatment)

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17 pages, 3243 KiB

Open AccessArticle

Description of Virulent Factors and Horizontal Gene Transfers of Keratitis-Associated Amoeba Acanthamoeba Triangularis by Genome Analysis

by Issam Hasni, Julien Andréani, Philippe Colson and Bernard La Scola

Pathogens 2020, 9(3), 217; https://doi.org/10.3390/pathogens9030217 - 16 Mar 2020

Cited by 15 | Viewed by 3350

Abstract

Acanthamoeba triangularis strain SH 621 is a free-living amoeba belonging to Acanthamoeba ribo-genotype T4. This ubiquitous protist is among the free-living amoebas responsible for Acanthamoeba keratitis, a severe infection of human cornea. Genome sequencing and genomic comparison were carried out to explore the [...] Read more.

Acanthamoeba triangularis strain SH 621 is a free-living amoeba belonging to Acanthamoeba ribo-genotype T4. This ubiquitous protist is among the free-living amoebas responsible for Acanthamoeba keratitis, a severe infection of human cornea. Genome sequencing and genomic comparison were carried out to explore the biological functions and to better understand the virulence mechanism related to the pathogenicity of Acanthamoeba keratitis. The genome assembly harbored a length of 66.43 Mb encompassing 13,849 scaffolds. The analysis of predicted proteins reported the presence of 37,062 ORFs. A complete annotation revealed 33,168 and 16,605 genes that matched with NCBI non-redundant protein sequence (nr) and Cluster of Orthologous Group of proteins (COG) databases, respectively. The Kyoto Encyclopedia of Genes and Genomes Pathway (KEGG) annotation reported a great number of genes related to carbohydrate, amino acid and lipid metabolic pathways. The pangenome performed with 8 available amoeba genomes belonging to genus Acanthamoeba revealed a core genome containing 843 clusters of orthologous genes with a ratio core genome/pangenome of less than 0.02. We detected 48 genes related to virulent factors of Acanthamoeba keratitis. Best hit analyses in nr database identified 99 homologous genes shared with amoeba-resisting microorganisms. This study allows the deciphering the genome of a free-living amoeba with medical interest and provides genomic data to better understand virulence-related Acanthamoeba keratitis. Full article

(This article belongs to the Special Issue Selected Papers from the International Meeting on the Biology and Pathogenicity of Free-Living Amoebae (FLAM2019))

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18 pages, 323 KiB

Open AccessEditor’s ChoiceReview

Immunotherapy against Prion Disease

by Yue Ma and Jiyan Ma

Pathogens 2020, 9(3), 216; https://doi.org/10.3390/pathogens9030216 - 14 Mar 2020

Cited by 16 | Viewed by 5151

Abstract

The term “prion disease” encompasses a group of neurodegenerative diseases affecting both humans and animals. Currently, there is no effective therapy and all forms of prion disease are invariably fatal. Because of (a) the outbreak of bovine spongiform encephalopathy in cattle and variant [...] Read more.

The term “prion disease” encompasses a group of neurodegenerative diseases affecting both humans and animals. Currently, there is no effective therapy and all forms of prion disease are invariably fatal. Because of (a) the outbreak of bovine spongiform encephalopathy in cattle and variant Creutzfeldt–Jakob disease in humans; (b) the heated debate about the prion hypothesis; and (c) the availability of a natural prion disease in rodents, the understanding of the pathogenic process in prion disease is much more advanced compared to that of other neurodegenerative disorders, which inspired many attempts to develop therapeutic strategies against these fatal diseases. In this review, we focus on immunotherapy against prion disease. We explain our rationale for immunotherapy as a plausible therapeutic choice, review previous trials using either active or passive immunization, and discuss potential strategies for overcoming the hurdles in developing a successful immunotherapy. We propose that immunotherapy is a plausible and practical therapeutic strategy and advocate more studies in this area to develop effective measures to control and treat these devastating disorders. Full article

(This article belongs to the Special Issue Prions and Prion-Like Transmissible Protein Pathogens)

13 pages, 3359 KiB

Open AccessArticle

Isolation, Characterization, and Application of a Bacteriophage Infecting the Fish Pathogen Aeromonas hydrophila

by Muhammad Akmal, Aryan Rahimi-Midani, Muhammad Hafeez-ur-Rehman, Ali Hussain and Tae-Jin Choi

Pathogens 2020, 9(3), 215; https://doi.org/10.3390/pathogens9030215 - 13 Mar 2020

Cited by 54 | Viewed by 6452

Abstract

Bacteriophages are increasingly being used as biological control agents against pathogenic bacteria. In the present study, we isolate and characterize bacteriophage Akh-2 from Geoje Island, South Korea, to evaluate its utility in controlling motile Aeromonas septicemia. Akh-2 lysed four of the seven Aeromonas [...] Read more.

Bacteriophages are increasingly being used as biological control agents against pathogenic bacteria. In the present study, we isolate and characterize bacteriophage Akh-2 from Geoje Island, South Korea, to evaluate its utility in controlling motile Aeromonas septicemia. Akh-2 lysed four of the seven Aeromonas hydrophila strains tested. Transmission electron microscopy analysis showed that Akh-2 belongs to the Siphoviridae family, with head and tail sizes of 50 ± 5 and 170 ± 5 nm, respectively. One-step growth curve analysis revealed that the phage has a latent period of 50 ± 5 min and a burst size of 139 ± 5 plaque-forming units per infected cell. The phage appeared stable in a pH range of 6–8 and a temperature range of −80 to 46 °C. Based on next-generation sequencing analysis, its genome is 114,901 bp in size, with a 44.22% G + C content and 254 open reading frames. During an artificial induction of the disease, loach (Misgurnus anguillicaudatus) treated with Akh-2 showed an increased survival rate and time compared with the non-treated control. Our results suggest that Akh-2 is a potential biological agent for the treatment of Aeromonas infections in fish. Full article

(This article belongs to the Special Issue Phage Therapy in Aquaculture: Current Developments and Future Challenges)

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24 pages, 4228 KiB

Open AccessEditor’s ChoiceArticle

Viromes of Ten Alfalfa Plants in Australia Reveal Diverse Known Viruses and a Novel RNA Virus

by Samira Samarfard, Alistair R. McTaggart, Murray Sharman, Nicolás E. Bejerman and Ralf G. Dietzgen

Pathogens 2020, 9(3), 214; https://doi.org/10.3390/pathogens9030214 - 13 Mar 2020

Cited by 17 | Viewed by 4752

Abstract

Alfalfa plants in the field can display a range of virus-like symptoms, especially when grown over many years for seed production. Most known alfalfa viruses have RNA genomes, some of which can be detected using diagnostic assays, but many viruses of alfalfa are [...] Read more.

Alfalfa plants in the field can display a range of virus-like symptoms, especially when grown over many years for seed production. Most known alfalfa viruses have RNA genomes, some of which can be detected using diagnostic assays, but many viruses of alfalfa are not well characterized. This study aims to identify the RNA and DNA virus complexes associated with alfalfa plants in Australia. To maximize the detection of RNA viruses, we purified double-stranded RNA (dsRNA) for high throughput sequencing and characterized the viromes of ten alfalfa samples that showed diverse virus-like symptoms. Using Illumina sequencing of tagged cDNA libraries from immune-captured dsRNA, we identified sequences of the single-stranded RNA viruses, alfalfa mosaic virus (AMV), bean leafroll virus, a new emaravirus tentatively named alfalfa ringspot-associated virus, and persistent dsRNA viruses belonging to the families Amalgaviridae and Partitiviridae. Furthermore, rolling circle amplification and restriction enzyme digestion revealed the complete genome of chickpea chlorosis Australia virus, a mastrevirus (family Geminiviridae) previously reported only from chickpea and French bean that was 97% identical to the chickpea isolate. The sequence data also enabled the assembly of the first complete genome (RNAs 1–3) of an Australian AMV isolate from alfalfa. Full article

(This article belongs to the Section Plant Pathogens)

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17 pages, 3981 KiB

Open AccessArticle

Biological Control of Tomato Gray Mold Caused by Botrytis Cinerea with the Entomopathogenic Fungus Metarhizium Anisopliae

by Most.Sinthia Sarven, Qiuyan Hao, Junbo Deng, Fang Yang, Gaofeng Wang, Yannong Xiao and Xueqiong Xiao

Pathogens 2020, 9(3), 213; https://doi.org/10.3390/pathogens9030213 - 13 Mar 2020

Cited by 31 | Viewed by 7056

Abstract

Gray mold disease caused by Botrytis cinerea is a devastating disease that leads to serious financial loss. In this study, the entomopathogenic fungus Metarhizium anisopliae that acts against the gray mold pathogen B. cinerea was evaluated. M. anisopliae produced a significant inhibition zone [...] Read more.

Gray mold disease caused by Botrytis cinerea is a devastating disease that leads to serious financial loss. In this study, the entomopathogenic fungus Metarhizium anisopliae that acts against the gray mold pathogen B. cinerea was evaluated. M. anisopliae produced a significant inhibition zone in front of the B. cinerea colony in the dual culture test. In addition, volatile organic compounds generated by M. anisopliae were shown to have an inhibitory effect on B. cinerea mycelia growth and reduced 41% of gray mold severity of postharvest tomatoes. The 10% concentration of the culture filtrate of M. anisopliae inhibited 88.62% of colony radial growth as well as 63.85% of sclerotia germination and all conidia germination of B. cinerea. Furthermore, the culture filtrate of M. anisopliae retained its inhibitory effect against the radial growth of B. cinerea even after heating for 15 min at 100 °C. Feasible mechanisms of M. anisopliae involved in the control of B. cinerea were explored, and it was demonstrated that the plasma membrane of B. cinerea conidia was damaged by the product of metabolism of M. anisopliae. In addition, after treating with culture filtrate of M. anisopliae, the B. cinerea phenotype was shown to be abnormal, and cell organelles of B. cinerea mycelia were damaged significantly. A significant control efficacy of M. anisopliae against tomato gray mold was detected on both the detached leaf assay (84.24%) as well as the whole plant (72.38%). In addition, a 78% reduction in tomato fruit mold was detected at a 10% treated concentration of M. anisopliae. These findings suggest that M. anisopliae possesses potential as a biocontrol agent against tomato gray mold in the greenhouse and during the postharvest stage. Full article

(This article belongs to the Section Plant Pathogens)

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11 pages, 1650 KiB

Open AccessArticle

Distribution and Nucleotide Diversity of Yr15 in Wild Emmer Populations and Chinese Wheat Germplasm

by Yu He, Lihua Feng, Yun Jiang, Lianquan Zhang, Jun Yan, Gang Zhao, Jirui Wang, Guoyue Chen, Bihua Wu, Dengcai Liu, Lin Huang and Tzion Fahima

Pathogens 2020, 9(3), 212; https://doi.org/10.3390/pathogens9030212 - 13 Mar 2020

Cited by 15 | Viewed by 2965

Abstract

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating fungal disease of wheat. The wild emmer gene, Yr15 (Wtk1), which confers a strong broad-spectrum resistance to Pst isolates, is composed of kinase and pseudokinase domains. [...] Read more.

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating fungal disease of wheat. The wild emmer gene, Yr15 (Wtk1), which confers a strong broad-spectrum resistance to Pst isolates, is composed of kinase and pseudokinase domains. The analysis of 361 wild emmer accessions from a wide range of natural habitats confirms that functional Wtk1 is distributed mainly along a narrow axis from Mt. Carmel to Mt. Hermon regions, in the northern part of Israel, where environmental conditions are favorable to the onset of stripe rust. An analysis of full-length Wtk1 DNA sequences from 49 wild emmer accessions identified three haplotypes and extremely low nucleotide diversity (π = 0.00002). The sequence diversity of Wtk1 is 9.5 times lower than that of broad-spectrum partial resistance gene Yr36 (π = 0.00019), and both are in sharp contrast to the high level of nucleotide diversity previously reported for race-specific resistance genes (e.g., Lr10 and Pm3). However, the nonfunctional wtk1 sequences possess high level of nucleotide diversity (π = 0.07). These results may reflect the different resistance mechanisms and the different evolutionary processes that shaped these resistance genes. Yr15 was absent in 189 Chinese wheat landraces and was present in only 1.02% of the 583 tested modern Chinese wheat cultivars. These results corroborate our previous results showing that Yr15 was absent in 94% of a worldwide collection of 513 wheat cultivars, therefore indicating the importance of Yr15 in wheat stripe rust resistance breeding programs in China and elsewhere around the globe. Full article

(This article belongs to the Special Issue Genomics, Molecular, Genetics, and Diversity of Plant Disease Resistance)

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