Intestinal Protozoa: Strategies to Understand and Control

A special issue of Microorganisms (ISSN 2076-2607). This special issue belongs to the section "Parasitology".

Deadline for manuscript submissions: closed (30 September 2022) | Viewed by 13326

Special Issue Editors

Institut Pasteur of Lille, Center for Infection and Immunity of Lille, UMR CNRS 8204, INSERM U1019, University of Lille, University Hospital of Lille, 1 rue du Professeur Calmette, 59019, Lille, France
Interests: intestinal protozoa; parasitic diseases; Cryptosporidium; Blastocystis; epidemiology; transmission; zoonosis; molecular biology; omics; host-parasites interactions
Special Issues, Collections and Topics in MDPI journals
Institut Pasteur of Lille, Center for Infection and Immunity of Lille, UMR CNRS 8204, INSERM U1019, University of Lille, University Hospital of Lille, 1 rue du Professeur Calmette, 59019, Lille, France
Interests: intestinal protozoa; parasitic diseases; Cryptosporidium; Blastocystis; epidemiology; transmission; zoonosis; molecular biology; omics; host-parasites interactions
Special Issues, Collections and Topics in MDPI journals
Center for Infection and Immunity of Lille, Institut Pasteur of Lille, UMR CNRS 9017, INSERM U1019, University of Lille, University Hospital of Lille, Lille, France
Interests: intestinal protozoa; parasitic diseases; Cryptosporidium; Blastocystis; epidemiology; transmission; zoonosis; molecular biology; omics; host-parasites interactions; microbiota; genomics

Special Issue Information

Dear Colleagues,

Intestinal protozoa including Giardia, Entamoeba, Cryptosporidium, Blastocystis, and others are known to affect several hundred million people per year. Most of them represent a leading cause of morbidity, malnutrition, and mortality worldwide and are responsible for gastrointestinal infections, which, in the case of some of them, can be serious and even fatal, in particular in children and immunocompromised patients. The major mode of transmission of these microorganisms is the fecal-oral route, mainly through the consumption of contaminated water and food. Their prevalence in the human population is thus related to the fecal peril, and consequently, developing countries are the most concerned by these parasites. Lately, this peril has also increased in developed countries being enhanced by the dynamics of the global population mobility due to the international travels and migratory flows. Strikingly, despite their potential major impact on public health, these parasites remain poorly studied and generally neglected by health authorities, even though some of them have been included by the World Health Organization (WHO) in the list of waterborne parasites. In addition, few or no drug treatments are effective against these parasites.

For this Special Issue, we invite you to submit contributions on any aspects of intestinal protozoa including molecular epidemiology and genetic diversity, comparative genomics, transmission (anthroponotic, zoonotic, or in link with environmental sources), life cycle, host-parasite interactions, and their impact on digestive microbiota, the identification of virulence factors, the development of innovative research models and drug design. This Special Issue will therefore cover research topics ranging from the cell to the population and combining laboratory research and field studies. All of the reported data will expand our knowledge of the biology and physiopathology of these enteric parasites and have probable effects on their management in terms of our understanding of the risks and the development of preventive measures and control strategies. In this Special Issue, original research articles and reviews are welcome.

Dr. Eric Viscogliosi
Dr. Gabriela Certad
Dr. Magali Chabé
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Microorganisms is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Keywords: intestinal protozoa
  • epidemiology
  • genetic diversity
  • transmission
  • zoonosis
  • life cycle
  • host–parasite interactions
  • microbiota
  • OMICs
  • drug design

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

12 pages, 2102 KiB  
Article
Prevalence, Subtype Distribution and Zoonotic Significance of Blastocystis sp. Isolates from Poultry, Cattle and Pets in Northern Egypt
Microorganisms 2022, 10(11), 2259; https://doi.org/10.3390/microorganisms10112259 - 14 Nov 2022
Cited by 6 | Viewed by 1688
Abstract
Blastocystis sp. is a widespread enteric protozoan that frequently infects human and animal groups. Despite its burden and zoonotic potential worldwide, epidemiological investigations remain limited in animal groups that come in contact with humans. Therefore, the largest survey ever conducted in North Africa [...] Read more.
Blastocystis sp. is a widespread enteric protozoan that frequently infects human and animal groups. Despite its burden and zoonotic potential worldwide, epidemiological investigations remain limited in animal groups that come in contact with humans. Therefore, the largest survey ever conducted in North Africa was performed in Egypt with the aim to investigate the prevalence and subtype (ST) distribution of Blastocystis sp. in animals. For this purpose, a total of 889 fecal specimens were collected from chickens (217), cattle (373), dogs (144) and cats (155) from six governorates of northern Egypt. These specimens were then screened for the presence of Blastocystis sp. using a quantitative real-time PCR, followed by subtyping the isolates. The overall prevalence of Blastocystis sp. reached 9.2% (82/889), with the highest infection rates reported in chickens (17.0%) and domestic cattle (11.0%), highlighting an active circulation of the parasite in both animal groups. In contrast, the low prevalence in cats (2.6%) and the absence of the parasite in dogs suggested that pets are not natural hosts of Blastocystis sp. ST10 and ST14 were largely predominant in cattle, confirming that both STs represented cattle-adapted STs. The report of one ST3 and one ST4 isolate in this animal group could be explained by an accidental zoonosis from humans to animals. All but one of the subtyped isolates in poultry belonged to ST7, which was considered as an avian ST. The presence of a remaining isolate of ST14 likely reflected a transient infection from contact between birds and cattle feces. The same environmental contamination was also likely the source of the ST14 infection in three of the four positive cats, with the remaining animals infected by ST3 as the result of human-to-animal transmission. These occurrences and subtyping data, combined with those previously collected in the Egyptian population, implies that poultry could play a significant role as reservoir for zoonotic transmission, which would not be the case for cattle and pets. Full article
(This article belongs to the Special Issue Intestinal Protozoa: Strategies to Understand and Control)
Show Figures

Figure 1

22 pages, 3430 KiB  
Article
Comparative Surfaceome Analysis of Clonal Histomonas meleagridis Strains with Different Pathogenicity Reveals Strain-Dependent Profiles
Microorganisms 2022, 10(10), 1884; https://doi.org/10.3390/microorganisms10101884 - 21 Sep 2022
Cited by 1 | Viewed by 1989
Abstract
Histomonas meleagridis, a poultry-specific intestinal protozoan parasite, is histomonosis’s etiological agent. Since treatment or prophylaxis options are no longer available in various countries, histomonosis can lead to significant production losses in chickens and mortality in turkeys. The surfaceome of microbial pathogens is a [...] Read more.
Histomonas meleagridis, a poultry-specific intestinal protozoan parasite, is histomonosis’s etiological agent. Since treatment or prophylaxis options are no longer available in various countries, histomonosis can lead to significant production losses in chickens and mortality in turkeys. The surfaceome of microbial pathogens is a crucial component of host–pathogen interactions. Recent proteome and exoproteome studies on H. meleagridis produced molecular data associated with virulence and in vitro attenuation, yet the information on proteins exposed on the cell surface is currently unknown. Thus, in the present study, we identified 1485 proteins and quantified 22 and 45 upregulated proteins in the virulent and attenuated strains, respectively, by applying cell surface biotinylation in association with high-throughput proteomic analysis. The virulent strain displayed upregulated proteins that could be linked to putative virulence factors involved in the colonization and establishment of infection, with the upregulation of two candidates being confirmed by expression analysis. In the attenuated strain, structural, transport and energy production proteins were upregulated, supporting the protozoan’s adaptation to the in vitro environment. These results provide a better understanding of the surface molecules involved in the pathogenesis of histomonosis, while highlighting the pathogen’s in vitro adaptation processes. Full article
(This article belongs to the Special Issue Intestinal Protozoa: Strategies to Understand and Control)
Show Figures

Figure 1

10 pages, 710 KiB  
Article
The Effect of Short-Chain Fatty Acids on Growth of Cryptosporidium parvum In Vitro
Microorganisms 2022, 10(9), 1822; https://doi.org/10.3390/microorganisms10091822 - 11 Sep 2022
Cited by 4 | Viewed by 1415
Abstract
In a previous study, we observed an increase in the severity of cryptosporidial infection corresponding to decreased levels of short-chain fatty acids (SCFAs). Therefore, we decided to examine the effect of SCFAs on Cryptosporidium growth in human ileocecal adenocarcinoma (HTC-8) cells. HTC-8 cells [...] Read more.
In a previous study, we observed an increase in the severity of cryptosporidial infection corresponding to decreased levels of short-chain fatty acids (SCFAs). Therefore, we decided to examine the effect of SCFAs on Cryptosporidium growth in human ileocecal adenocarcinoma (HTC-8) cells. HTC-8 cells were infected with 1 × 105 C. parvum oocysts. After 48 h of incubation with selected SCFAs, cells were fixed and labeled with monoclonal antibody directed to all intracellular stages, and the number of parasites was quantitated using a fluorescent microscope. Acetate, butyrate, propionate and valproate significantly inhibited growth, with an EC50 between 4 and 10 mM. Additionally, when combined, butyrate, acetate and propionate showed increased efficacy. Butyrate also inhibited growth when incubated with sporozoites prior to infection of host cell monolayers. In addition, we looked at possible mechanisms of action of inhibition. A combination of C. parvum infection and butyrate treatment led to increases in apoptosis and certain inflammatory cytokines. We conclude that acetate, propionate and butyrate have direct inhibitory activities in host cells against C. parvum, and butyrate can also affect sporozoite infectivity directly. While not preventing infection, SCFAs may help in keeping the infection low or in check. Full article
(This article belongs to the Special Issue Intestinal Protozoa: Strategies to Understand and Control)
Show Figures

Figure 1

19 pages, 1018 KiB  
Article
Detection, Molecular Identification and Transmission of the Intestinal Protozoa Blastocystis sp. in Guinea from a Large-Scale Epidemiological Study Conducted in the Conakry Area
Microorganisms 2022, 10(2), 446; https://doi.org/10.3390/microorganisms10020446 - 15 Feb 2022
Cited by 8 | Viewed by 2377
Abstract
Blastocystis sp. is a single-celled parasite estimated to colonize the digestive tract of 1 to 2 billion people worldwide. Although it represents the most frequent intestinal protozoa in human stools, it remains still under-investigated in countries with a high risk of infection due [...] Read more.
Blastocystis sp. is a single-celled parasite estimated to colonize the digestive tract of 1 to 2 billion people worldwide. Although it represents the most frequent intestinal protozoa in human stools, it remains still under-investigated in countries with a high risk of infection due to poor sanitary and hygiene conditions, such as in Africa. Therefore, the present study was carried out to determine the prevalence and subtype (ST) distribution of Blastocystis sp. in the Guinean population. For this purpose, fecal samples were collected from 500 individuals presenting or not digestive disorders in two hospitals of Conakry. Search for the parasite in stools was performed by real-time PCR targeting the small subunit rDNA gene followed by sequencing of the PCR products for subtyping of the isolates. A total of 390 participants (78.0%) was positive for Blastocystis sp. Five STs were identified in the Guinean cohort (ST1, ST2, ST3, ST4 and ST14) with varying frequency, ST3 being predominant. Among them, ST4 was found in only two patients confirming its global rarity in Africa whereas infections by ST14 were likely the result of zoonotic transmission from bovid. No significant association was detected between Blastocystis sp. colonization or ST distribution and the symptomatic status of Guinean subjects or the presence of digestive symptoms. In contrast, drilling water consumption represented a significant risk factor for infection by Blastocystis sp. Predominance of ST3 coupled with its low intra-ST diversity strongly suggested large-scale human-to-human transmission of this ST within this cohort. In parallel, the highest intra-ST diversity of ST1 and ST2 was likely correlated with various potential sources of infection in addition to anthroponotic transmission. These findings highlighted the active circulation of the parasite in Guinea as reported in some low-income African countries and the necessity to implement prevention and control measures in order to limit the circulation of this parasite in this endemic geographical area. Full article
(This article belongs to the Special Issue Intestinal Protozoa: Strategies to Understand and Control)
Show Figures

Figure 1

14 pages, 2278 KiB  
Article
Comparative Characterization of CpCDPK1 and CpCDPK9, Two Potential Drug Targets Against Cryptosporidiosis
Microorganisms 2022, 10(2), 333; https://doi.org/10.3390/microorganisms10020333 - 01 Feb 2022
Cited by 4 | Viewed by 1632
Abstract
As the invasion, egress, and growth of Cryptosporidium spp. are regulated by the calcium ion, calcium-dependent protein kinases (CDPKs) are considered potential drug targets against these pathogens. In this study, we expressed CpCDPK1 of Cryptosporidium parvum encoded by the cgd3_920 gene and CpCDPK9 [...] Read more.
As the invasion, egress, and growth of Cryptosporidium spp. are regulated by the calcium ion, calcium-dependent protein kinases (CDPKs) are considered potential drug targets against these pathogens. In this study, we expressed CpCDPK1 of Cryptosporidium parvum encoded by the cgd3_920 gene and CpCDPK9 encoded by the the cgd7_1260 gene in Escherichia coli, and we conducted some comparative studies with quantitative PCR, immunofluorescence staining, and in vitro neutralization assays. By immunofluorescence microscopy, CpCDPK1 was expressed over the entirety of the sporozoites, while CpCDPK9 was mainly expressed in the apical region. The expression of the cgd3_920 gene was the highest at 12 h of the in vitro culture, whereas the expression of the cgd7_1260 gene peaked between 2 h and 6 h. Polyclonal antibodies against these two CpCDPK proteins had similar neutralization efficiency on C. parvum growth, reaching approximately 40%. Of the 50 candidate compounds from the molecular docking of CpCDPK1, 10 had significant in vitro anti-cryptosporidial effects, but only one inhibited enzyme activity. For CpCDPK9, five of the forty-five candidate compounds showed significant in vitro anti-cryptosporidial effects. Results obtained from this study suggest that CpCDPK1 and CpCDPK9 might function differently in C. parvum infection. Full article
(This article belongs to the Special Issue Intestinal Protozoa: Strategies to Understand and Control)
Show Figures

Figure 1

23 pages, 4975 KiB  
Article
Persistent Cryptosporidium parvum Infection Leads to the Development of the Tumor Microenvironment in an Experimental Mouse Model: Results of a Microarray Approach
Microorganisms 2021, 9(12), 2569; https://doi.org/10.3390/microorganisms9122569 - 12 Dec 2021
Cited by 5 | Viewed by 3367
Abstract
Cryptosporidium spp. are enteric protozoa parasites that infect a variety of vertebrate hosts. These parasites are capable of inducing life-threatening gastrointestinal disease in immunocompromised individuals. With the rising epidemiological evidence of the occurrence of Cryptosporidium infections in humans with digestive cancer, the tumorigenic [...] Read more.
Cryptosporidium spp. are enteric protozoa parasites that infect a variety of vertebrate hosts. These parasites are capable of inducing life-threatening gastrointestinal disease in immunocompromised individuals. With the rising epidemiological evidence of the occurrence of Cryptosporidium infections in humans with digestive cancer, the tumorigenic potential of the parasite has been speculated. In this regard, Cryptosporidium parvum has been reported to induce digestive adenocarcinoma in a rodent model of chronic cryptosporidiosis. However, the processes by which the parasite could induce this carcinogenesis are still unknown. Therefore, the transcriptomes of C. parvum infected ileo-cecal regions of mice developing tumors were analyzed in the current study. For the first time, downregulation of the expression of α-defensin, an anti-microbial target of the parasite in response to C. parvum infection was observed in the transformed tissues. This phenomenon has been speculated to be the result of resistance of C. parvum to the host defense through the upregulated expression of interferon γ-stimulated genes. The inflammatory response generated as result of attenuated expression of anti-microbial peptides highlights the role of immune evasion in the C. parvum-induced tumorigenesis. The study has also succeeded in the characterization of the tumor microenvironment (TME) which is characterized by the presence of cancer associated fibroblasts, myeloid-derived suppressor cells, tumor-associated macrophages and extracellular matrix components. Identification of immune suppressor cells and accumulation of pro-inflammatory mediators speculates that chronic inflammation induced by persistent C. parvum infection assists in development of an immunosuppressive tumor microenvironment. Full article
(This article belongs to the Special Issue Intestinal Protozoa: Strategies to Understand and Control)
Show Figures

Figure 1

Back to TopTop