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Clinical Microbiology Reviews Jan 2013Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported... (Review)
Review
Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported different degrees of pathogenicity and virulence among Cryptosporidium species and isolates of the same species as well as evidence of variation in host susceptibility to infection. The identification and validation of Cryptosporidium virulence factors have been hindered by the renowned difficulties pertaining to the in vitro culture and genetic manipulation of this parasite. Nevertheless, substantial progress has been made in identifying putative virulence factors for Cryptosporidium. This progress has been accelerated since the publication of the Cryptosporidium parvum and C. hominis genomes, with the characterization of over 25 putative virulence factors identified by using a variety of immunological and molecular techniques and which are proposed to be involved in aspects of host-pathogen interactions from adhesion and locomotion to invasion and proliferation. Progress has also been made in the contribution of host factors that are associated with variations in both the severity and risk of infection. Here we provide a review comprised of the current state of knowledge on Cryptosporidium infectivity, pathogenesis, and transmissibility in light of our contemporary understanding of microbial virulence.
Topics: Animals; Cryptosporidiosis; Cryptosporidium; Gastroenteritis; Host-Pathogen Interactions; Humans; Virulence; Virulence Factors
PubMed: 23297262
DOI: 10.1128/CMR.00076-12 -
Microbiology (Reading, England) May 2019The protozoan Cryptosporidium is notorious for its resistance to chlorine disinfection, a mainstay of water treatment. Human infections, mainly of the small intestine,...
The protozoan Cryptosporidium is notorious for its resistance to chlorine disinfection, a mainstay of water treatment. Human infections, mainly of the small intestine, arise from consumption of faecally contaminated food or water, environmental exposure, and person-to-person or animal-to-person spread. Acute gastrointestinal symptoms can be prolonged but are usually self-limiting. Problems arise with immune-deficient, including malnourished, people including chronic diarrhoea, hepato-biliary tree and extra-gastrointestinal site infection, and few options for treatment or prevention exist. Although genomics has enabled refined classification, identification of chemotherapeutic targets and vaccine candidates, and putative factors for host adaption and pathogenesis, their confirmation has been hampered by a lack of biological tools.
Topics: Animals; Cryptosporidiosis; Cryptosporidium; Genome, Protozoan; Humans; Phylogeny
PubMed: 31268415
DOI: 10.1099/mic.0.000764 -
Parasite (Paris, France) 2020While cryptosporidiosis is recognized as being among the most common causes of human parasitic diarrhea in the world, there is currently limited knowledge on... (Review)
Review
While cryptosporidiosis is recognized as being among the most common causes of human parasitic diarrhea in the world, there is currently limited knowledge on Cryptosporidium infection mechanisms, incomplete codification of diagnostic methods, and a need for additional therapeutic options. In response, the Seventh International Giardia and Cryptosporidium Conference (IGCC 2019) was hosted from 23 to 26 June 2019, at the Rouen Normandy University, France. This trusted event brought together an international delegation of researchers to synthesize recent advances and identify key research questions and knowledge gaps. The program of the interdisciplinary conference included all aspects of host-parasite relationships from basic research to applications to human and veterinary medicine, and environmental issues associated with waterborne parasites and their epidemiological consequences. In relation to Cryptosporidium and cryptosporidiosis, the primary research areas for which novel findings and the most impressive communications were presented and discussed included: Cryptosporidium in environmental waters, seafood, and fresh produce; Animal epidemiology; Human cryptosporidiosis and epidemiology; Genomes and genomic evolution encompassing: Comparative genomics of Cryptosporidium spp., Genomic insights into biology, Acquiring and utilizing genome sequences, Genetic manipulation; Host-parasite interaction (immunology, microbiome); and Diagnosis and treatment. High quality presentations discussed at the conference reflected decisive progress and identified new opportunities that will engage investigators and funding agencies to spur future research in a "one health" approach to improve basic knowledge and the clinical and public health management of zoonotic cryptosporidiosis.
Topics: Animals; Congresses as Topic; Cryptosporidiosis; Cryptosporidium; Diarrhea; Feces; France; Genotype; Giardia; Giardiasis; Humans; One Health
PubMed: 32167464
DOI: 10.1051/parasite/2020011 -
Parasite (Paris, France) 2023Free-Living Amebae (FLA) and Cryptosporidium oocysts occasionally share the same environment. From 2004 to 2016, Cryptosporidium was responsible for 60% of 905 worldwide...
Free-Living Amebae (FLA) and Cryptosporidium oocysts occasionally share the same environment. From 2004 to 2016, Cryptosporidium was responsible for 60% of 905 worldwide waterborne outbreaks caused by protozoan parasites. The aim of this study was to evaluate interactions between C. parvum oocysts and two common FLAs (Acanthamoeba castellanii and Vermamoeba vermiformis) in a water environment. Encystment and survival of FLAs were evaluated by microscopy using trypan blue vital coloration. Oocysts were numerated on microscopy. Interactions were studied over time in conditions both unfavorable and favorable to phagocytosis. Potential phagocytosis was directly evaluated by several microscopic approaches and indirectly by numeration of microorganisms and oocyst infectivity evaluation. Occasional phagocytosis of C. parvum by FLAs was documented. However, oocyst concentrations did not decrease significantly, suggesting resistance of oocysts to phagocytosis. A temporary decrease of oocyst infectivity was observed in the presence of A. castellanii. The effect of these interactions on C. parvum infectivity is particularly interesting. The biofilm condition could favor the persistence or even the proliferation of oocysts over time. This study demonstrated interactions between C. parvum and FLAs. Further knowledge of the mechanisms involved in the decrease of oocyst infectivity in the presence of A. castellanii could facilitate the development of new therapeutic approaches.
Topics: Animals; Cryptosporidium parvum; Amoeba; Cryptosporidium; Cryptosporidiosis; Disease Outbreaks; Oocysts
PubMed: 37606589
DOI: 10.1051/parasite/2023033 -
Current Opinion in Microbiology Dec 2020Cryptosporidium is a leading cause of diarrhea and death in young children and untreated AIDS patients in resource-poor settings, and of waterborne outbreaks of disease... (Review)
Review
Cryptosporidium is a leading cause of diarrhea and death in young children and untreated AIDS patients in resource-poor settings, and of waterborne outbreaks of disease in developed countries. However, there is no consistently effective treatment for vulnerable populations. Progress towards development of therapeutics for cryptosporidiosis has been hampered by lack of optimal culture systems to study it. New advances in organoid/enteroid technology have contributed to improved platforms to culture and propagate Cryptosporidium. Here we discuss recent breakthroughs in the field and highlight different models for functional ex vivo organoid or enteroidderived culture systems. These systems will lead to a better understanding of the mechanisms of host-parasite interactions in vivo.
Topics: Animals; Cell Culture Techniques; Cryptosporidiosis; Cryptosporidium; Humans; Intestines; Models, Biological; Organoids
PubMed: 33113480
DOI: 10.1016/j.mib.2020.10.002 -
Genes Jun 2021Cryptosporidiosis is ranked sixth in the list of the most important food-borne parasites globally, and it is an important contributor to mortality in infants and the... (Review)
Review
Cryptosporidiosis is ranked sixth in the list of the most important food-borne parasites globally, and it is an important contributor to mortality in infants and the immunosuppressed. Recently, the number of genome sequences available for this parasite has increased drastically. The majority of the sequences are derived from population studies of and , the most important species causing disease in humans. Work with this parasite is challenging since it lacks an optimal, prolonged, in vitro culture system, which accurately reproduces the in vivo life cycle. This obstacle makes the cloning of isolates nearly impossible. Thus, patient isolates that are sequenced represent a population or, at times, mixed infections. Oocysts, the lifecycle stage currently used for sequencing, must be considered a population even if the sequence is derived from single-cell sequencing of a single oocyst because each oocyst contains four haploid meiotic progeny (sporozoites). Additionally, the community does not yet have a set of universal markers for strain typing that are distributed across all chromosomes. These variables pose challenges for population studies and require careful analyses to avoid biased interpretation. This review presents an overview of existing population studies, challenges, and potential solutions to facilitate future population analyses.
Topics: Cryptosporidiosis; Cryptosporidium; Genetic Variation; Genotyping Techniques; Humans; Oocysts
PubMed: 34200631
DOI: 10.3390/genes12060894 -
PLoS Neglected Tropical Diseases Aug 2022Zoonotic Cryptosporidium parvum infections are mainly caused by IIa and IId subtypes. As most biological characterizations have been performed on IIa subtypes, the...
Zoonotic Cryptosporidium parvum infections are mainly caused by IIa and IId subtypes. As most biological characterizations have been performed on IIa subtypes, the biological and genetic characteristics of IId subtypes in China are not clear. We evaluated the infection and genetic characteristics of IId isolates in interferon-γ-knockout mice using qPCR to quantify oocyst shedding, histological examination to monitor pathological changes and comparative genomic analyses to identify infectivity and virulence-associated differences. Compared with the reference IIa isolate, mice infected with the IId isolates had significantly higher and longer oocyst shedding and lower body weight gain. In addition, the four IId isolates examined differed significantly in infectivity (as indicated by the median infective dose), oocyst shedding duration, and pathogenicity. Comparative genomic analysis indicated that the IId isolates had three more subtelomeric genes than the reference IIa isolate and 5385-5548 nucleotide substitutions, with the hypervariable genes mostly in two blocks on chromosome 1. In contrast, the four IId isolates differed from each other by 77-1,452 nucleotides, with virulence-associated sequence differences mainly in nine genes within a 28-kb block on chromosome 6. These data indicate the newly emerged C. parvum IId subtypes in China have high animal infectivity and unique genomic characteristics.
Topics: Animals; China; Cryptosporidiosis; Cryptosporidium; Cryptosporidium parvum; Feces; Genomics; Mice; Oocysts; Zoonoses
PubMed: 35994488
DOI: 10.1371/journal.pntd.0010714 -
Clinical Microbiology and Infection :... Jun 2016Cryptosporidium has emerged as a significant cause of diarrhoeal disease worldwide, with severe health consequences for very young, malnourished children living in... (Review)
Review
Cryptosporidium has emerged as a significant cause of diarrhoeal disease worldwide, with severe health consequences for very young, malnourished children living in endemic areas and for individuals with highly impaired T-cell functions. In Europe, as elsewhere, the burden of disease has been difficult to measure as a result of the lack of appropriate, standardized surveillance and monitoring systems. The recent occurrence of large water- and foodborne outbreaks in several EU countries, as well as the results of many surveys of human and animal cryptosporidiosis, indicate that this parasite is widespread. Specific subtypes of the zoonotic Cryptosporidium parvum and the anthroponotic C. hominis are responsible for the majority of human cases in Europe. No treatment is currently available to clear the infection, but recent progress in genetic engineering of the parasite, coupled with advances in genomics, have opened important avenues for future research. Here we explore the possible reasons for underascertainment of cryptosporidiosis and the importance of accurate diagnosis in clinical management, the epidemiology of human cryptosporidiosis and key messages from recent outbreaks to highlight important interventions and emerging public health issues.
Topics: Cryptosporidiosis; Cryptosporidium; Disease Outbreaks; Europe; Genotype; Humans; Prevalence
PubMed: 27172805
DOI: 10.1016/j.cmi.2016.04.021 -
Parasite Immunology 2012We describe recent advances in the genomics and population biology of Cryptosporidium parvum and C. hominis, the causative agents of cryptosporidiosis in humans and... (Review)
Review
We describe recent advances in the genomics and population biology of Cryptosporidium parvum and C. hominis, the causative agents of cryptosporidiosis in humans and animals. Many basic aspects of the biology of Cryptosporidium species remain to be investigated and effective drugs to control cryptosporidiosis are not available. Sequencing and annotation of the genome of C. parvum and C. hominis has uncovered unique features of the metabolism of these species. The recently sequenced genome of the gastric species C. muris is providing new insights into the evolution of the genus. Cryptosporidian sequence information has facilitated the identification of polymorphic genetic markers. Genotyping of oocysts excreted by human and animal hosts using such markers has revealed many new species and genotypes, and is leading to a better understanding of the epidemiology of cryptosporidiosis.
Topics: Animals; Cryptosporidiosis; Cryptosporidium; Genetic Markers; Genome, Protozoan; Genomics; Humans; Oocysts; Species Specificity
PubMed: 21595702
DOI: 10.1111/j.1365-3024.2011.01301.x -
International Journal For Parasitology.... Dec 2020Cryptosporidium and Toxoplasma are parasites that have caused problems worldwide. Cryptosporidium causes severe watery diarrhoea and may be fatal in immunocompromised...
Cryptosporidium and Toxoplasma are parasites that have caused problems worldwide. Cryptosporidium causes severe watery diarrhoea and may be fatal in immunocompromised patients and in infants. Nitazoxanide is the only agent currently approved by the FDA, but its efficacy is limited. Toxoplasmosis is also a problem in the immunocompromised, as currently available treatment options have limited efficacy and patient tolerance can be poor. In the present investigation, we screened libraries of epigenetic compounds to identify those that inhibited C. parvum growth. Nullscript was identified as a compound with an inhibitory effect on C. parvum and T. gondii growth, and was less toxic to host cells. Nullscript was also able to significantly decrease oocyst excretion in C. parvum-infected SCID mice.
Topics: Animals; Cryptosporidiosis; Cryptosporidium; Cryptosporidium parvum; Humans; Mice; Mice, SCID; Toxoplasma
PubMed: 33120250
DOI: 10.1016/j.ijpddr.2020.10.004