Cryptosporidium and cryptosporidiosis in man and animals

Evaluation of molecular-based methods for the detection and quantification of Cryptosporidium spp. in wastewater

Cryptosporidium poses significant public health risks as a cause of waterborne disease worldwide. Clinical surveillance of cryptosporidiosis is largely underreported due to the asymptomatic and mildly symptomatic infections, clinical misdiagnoses, and barriers to access testing. Wastewater surveillance overcomes these limitations and could serve as an effective tool for identifying cryptosporidiosis at the population level. Despite its potential, the lack of standardized wastewater surveillance methods for Cryptosporidium spp. challenges implementation design and the comparability between studies. Thus, this study compared and contrasted Cryptosporidium wastewater surveillance methods for concentrating wastewater oocysts, extracting oocyst DNA, and detecting Cryptosporidium genetic markers. The evaluated concentration methods included electronegative membrane filtration, Envirocheck HV capsule filtration, centrifugation, and Nanotrap Microbiome Particles, with and without additional immunomagnetic separation purification (except for the Nanotrap Microbiome Particles). Oocyst DNA extraction by either the DNeasy Powersoil Pro kit and the QIAamp DNA Mini kit were evaluated and the impact of bead beating and freeze-thaw pretreatments on DNA recoveries was assessed. Genetic detection via qPCR assays targeting either the Cryptosporidium 18S rRNA gene or the Cryptosporidium oocyst wall protein gene were tested. Oocyst recovery percentages were highest for centrifugation (39-77 %), followed by the Nanotrap Microbiome Particles (24 %), electronegative filtration with a PBST elution (22 %), and Envirocheck HV capsule filtration (13 %). Immunomagnetic separation purification was found to be unsuitable due to interference from the wastewater matrix. Bead-beating pretreatment enhanced DNA recoveries from both the DNeasy Powersoil Pro kit (314 gc/μL DNA) and the QIAamp DNA Mini kit (238 gc/μL DNA). In contrast, freeze-thaw pretreatment reduced DNA recoveries to under 92 gc/μL DNA, likely through DNA degradation. Finally, while both qPCR assays were specific to Cryptosporidium spp., the 18S rRNA assay had a 5-fold lower detection limit and could detect a wider range of Cryptosporidium spp. than the Cryptosporidium oocyst wall protein assay.

Cryptosporidium-associated enteritis in captive koalas (Phascolarctos cinereus)

Cryptosporidium spp. sporadically infect a range of Australian native mammals including koalas, red kangaroos, eastern grey kangaroos, bilbies and brush tailed possums and can range from asymptomatic to fatal infections. Traditionally considered a disease of the young or immuno-compromised, and resulting in profuse diarrhoea in other species, here we report an atypical clinical syndrome associated with Cryptosporidium in a captive population of koalas. All affected animals were in-contact adults, and demonstrated anorexia, dehydration and abdominal pain in the absence of diarrhoea. Following euthanasia on welfare grounds, Cryptosporidium infection was confirmed postmortem in three of four symptomatic animals via faecal floatation and/or intestinal histopathology, with enteritis also diagnosed in the fourth koala. Further screening of the captive colony found the outbreak had been contained. Based on sequencing the cause of the infection was C. fayeri, but the source was undetermined. In conclusion, Cryptosporidium should be considered as a possible cause of generalised illness in koalas.

Minimal zoonotic risk of cryptosporidiosis and giardiasis from frogs and reptiles

The zoonotic potential of the protist parasites Cryptosporidium spp. and Giardia duodenalis in amphibians and reptiles raises public health concerns due to their growing popularity as pets. This review examines the prevalence and diversity of these parasites in wild and captive amphibians and reptiles to better understand the zoonotic risk. Research on Giardia in both groups is limited, and zoonotic forms of Cryptosporidium or Giardia have not been reported in amphibians. Host-adapted Cryptosporidium species dominate in reptiles, albeit some reptiles have been found to carry zoonotic (C. hominis and C. parvum) and rodent-associated (C. tyzzeri, C. muris and C. andersoni) species, primarily through mechanical carriage. Similarly, the limited reports of Giardia duodenalis (assemblages A, B and E) in reptiles may also be due to mechanical carriage. Thus, the available evidence indicates minimal zoonotic risk associated with these organisms in wild and captive frogs and reptiles. The exact transmission routes for these infections within reptile populations remain poorly understood, particularly regarding the importance of mechanical carriage. Although the risk appears minimal, continued research and surveillance efforts are necessary to gain a more comprehensive understanding of the transmission dynamics and ultimately improve our ability to safeguard human and animal health.

Effects of Cryptosporidium parvum infection on intestinal fungal microbiota in yaks (Bos grunniens)

During the last decade, researchers had started to focus on the relationship between intestinal parasitic infection and variation of intestinal microflora. Cryptosporidium is a widely known opportunistic and zoonotic pathogen. Several studies have shown that Cryptosporidium infection has impact to alter the gut microflora. However, there are only few studies referring to the fungal microflora changes in response to Cryptosporidium infection in highland ruminants. Therefore, the present study was performed for exploring the alternations of intestinal fungal microbiota in yaks after exposure to Cryptosporidium infection. In present study, Amplicon sequencing of ITS regions was used to study the variations of fungal microflora in yaks. After filtering the raw data, over 45 000 and 62 000 clean data were obtained in uninfected and infected yaks, respectively. By using alpha diversity analysis, it was found that there is no significant difference in the richness and evenness when positive samples were compared with negative ones, whereas intestinal fungal communities in different taxa in yaks were changed. The results of present study depicted that 2-phyla and 21-genera in the infected animals had significantly (P < 0.05) changed. These genera were Septoria, Coniothyrium, Cleistothelebolus, Bensingtonia, Cystobasidium, Filobasidium, Coprotus, Carex, Blumeria, Coprinellus, Leucosporidium, Phialophora, Isolepis, Ascobolus, Thecaphora, Mortierella, Urocystis, Symmetrospora and Lasiobolus. In addition, we found variations in 28 enzymes suggesting that the function of microbiota was also affected. It is concluded that there are drastic changes in the fungal microflora and microbiota functions after exposure to Cryptosporidium infection in yak. Our results help to focus on the prompt way for the development of new therapies to control Cryptosporidiosis.

Case Report: Severe Diarrhea Caused by Cryptosporidium Diagnosed by Metagenome Next-Generation Sequencing in Blood

Background

Cryptosporidium is one of the major pathogens causing diarrhea worldwide. At present, cryptosporidiosis is difficult to prevent and control, especially in immunocompromised hosts. It may cause life-threatening diarrhea and malabsorption among children and immunocompromised patients. Therefore, it is very important to explore rapid diagnostic tools and treatment methods for Cryptosporidium infection.

Case Presentation

We reported a case of severe diarrhea caused by cryptosporidiosis in a liver transplant recipient, whose condition was finally confirmed by metagenomic next-generation sequencing (mNGS) and fecal microscopy. His illness was resolved with immunosuppression regulation, nitazoxanide administration, and infection control.

Conclusion

So far, nitazoxanide is still the first choice for the treatment of cryptosporidiosis. Our institutional experience suggested that nitazoxanide alone may be effective on the basis of adjusting immunosuppressant. In addition, even though diagnosis of Cryptosporidium infection is a challenge, mNGS can serve as a rapid screening tool in low-prevalence setting.

Investigation of the prophylactic and therapeutic effectiveness of oral thyme extract in rats experimentally infected with cryptosporidium parvum

In this study, the prophylactic and therapeutic activities of thyme extract at different concentrations against experimental Cryptosporidium parvum infection in immunosuppressed rats were investigated. Thyme extract was prepared at four different concentrations (10%, 30%, 50%, and 100%) and administered as a single oral dose of 1 mL for evaluation of its prophylactic efficacy. Five consecutive days after infection was detected in all rats, therapeutic evaluations were also performed. According to the results obtained by daily counting of oocysts in stools, the prophylactic and therapeutic effects of thyme extract administration were significant in comparison to the control group (P˂0.01). Oocyst shedding continued in the control group at high numbers from the beginning to the end of the study, while oocyst counts in the prophylaxis groups remained low throughout the study. On the other hand, oocyst excretion rates were high in the therapeutic groups and decreased rapidly after thyme extract administration. At the end of the study, oocyst excretion had completely stopped for some rats administered thyme extract. There was no group in which oocyst shedding ceased for all rats. No significant differences were observed in the therapeutic or prophylaxis groups regarding the doses administered (P > 0.01). Renal and hepatic functions were monitored by measuring urea, creatinine, alanine transaminase, and aspartate transaminase levels ​​before and after thyme extract administration. As a result, it was concluded that oral thyme extract administration at the doses applied in this study is effective and safe in the prophylactic and therapeutic treatment of experimental cryptosporidiosis in rats.

Cryptosporidiosis threat under climate change in China: prediction and validation of habitat suitability and outbreak risk for human-derived Cryptosporidium based on ecological niche models

BACKGROUND

Cryptosporidiosis is a zoonotic intestinal infectious disease caused by Cryptosporidium spp., and its transmission is highly influenced by climate factors. In the present study, the potential spatial distribution of Cryptosporidium in China was predicted based on ecological niche models for cryptosporidiosis epidemic risk warning and prevention and control.

METHODS

The applicability of existing Cryptosporidium presence points in ENM analysis was investigated based on data from monitoring sites in 2011-2019. Cryptosporidium occurrence data for China and neighboring countries were extracted and used to construct the ENMs, namely Maxent, Bioclim, Domain, and Garp. Models were evaluated based on Receiver Operating Characteristic curve, Kappa, and True Skill Statistic coefficients. The best model was constructed using Cryptosporidium data and climate variables during 1986‒2010, and used to analyze the effects of climate factors on Cryptosporidium distribution. The climate variables for the period 2011‒2100 were projected to the simulation results to predict the ecological adaptability and potential distribution of Cryptosporidium in future in China.

RESULTS

The Maxent model (AUC = 0.95, maximum Kappa = 0.91, maximum TSS = 1.00) fit better than the other three models and was thus considered the best ENM for predicting Cryptosporidium habitat suitability. The major suitable habitats for human-derived Cryptosporidium in China were located in some high-population density areas, especially in the middle and lower reaches of the Yangtze River, the lower reaches of the Yellow River, and the Huai and the Pearl River Basins (cloglog value of habitat suitability > 0.9). Under future climate change, non-suitable habitats for Cryptosporidium will shrink, while highly suitable habitats will expand significantly (χ² = 76.641, P < 0.01; χ² = 86.836, P < 0.01), and the main changes will likely be concentrated in the northeastern, southwestern, and northwestern regions.

CONCLUSIONS

The Maxent model is applicable in prediction of Cryptosporidium habitat suitability and can achieve excellent simulation results. These results suggest a current high risk of transmission and significant pressure for cryptosporidiosis prevention and control in China. Against a future climate change background, Cryptosporidium may gain more suitable habitats within China. Constructing a national surveillance network could facilitate further elucidation of the epidemiological trends and transmission patterns of cryptosporidiosis, and mitigate the associated epidemic and outbreak risks.

Mammal-related Cryptosporidium infections in endemic reptiles of New Zealand

New Zealand's endemic reptile fauna is highly threatened and pathogens causing infectious diseases may be a significant risk to already endangered species. Here, we investigate Cryptosporidium infection in captive endemic New Zealand reptiles. We found two mammal-related Cryptosporidium species (C. hominis and C. parvum) and six subtypes from three gp60 families (Ib, Ig and IIa) in 12 individuals of captive endemic Tuatara, Otago and Grand skinks, and Jewelled and Rough geckos. Cryptosporidium serpentis was identified in two Jewelled geckos using 18S. In New Zealand, C. hominis and C. parvum are associated with infections in humans and introduced domestic animals but have also been recently found in wildlife. Our finding of Cryptosporidium infection in endemic reptiles can help inform strategies to monitor the conservation of species and manage potential introductions of pathogens to in-situ and ex-situ populations.

Cryptosporidium parvum maintains intracellular survival by activating the host cellular EGFR-PI3K/Akt signaling pathway

Autophagy is a critical cellular mechanism in helping infected cells remove intracellular pathogens and is countered by pathogens maintaining intracellular survival by regulating autophagy through the manipulation of the host cellular signal transduction pathway. Cryptosporidium parvum is a zoonotic intracellular but extracytoplasmic protozoon that causes diarrhea in infants and young children worldwide. However, it is still unclear how Cryptosporidium adapts to intracellular survival. In the present study, we demonstrated that C. parvum could activate the EGFR-PI3K/Akt signaling pathway to promote intracellular survival in HCT-8 cells. The western blot results showed that C. parvum induced EGFR and Akt phosphorylation in HCT-8 cells. The EGFR inhibitor AG1478 decreased EGFR and Akt phosphorylation, and the PI3K inhibitor LY294002 impaired Akt phosphorylation induced by C. parvum in HCT-8 cells. Inhibition of EGFR or Akt decreased the number of intracellular parasites. Second, low-dose infection of C. parvum triggered complete autophagy and enhanced autophagic flux in HCT-8 cells. The expressions of mTOR and p62 were decreased, and the expressions of LC3 and Beclin1 were increased in C. parvum-infected HCT-8 cells. Transfection with siBeclin1 or siATG7 reduced LC3 accumulation, while lysosome inhibitor E64d+pepA increased LC3 accumulation induced by C. parvum in HCT-8 cells. Intracellular parasite proliferation was decreased when treated with autophagy inducer rapamycin, whereas autophagy inhibitor 3-MA, E64d+pep A, siBeclin1 or siATG7 increased intracellular parasites. Third, C. parvum inhibited autophagy killing to promote its own intracellular survival by activating EGFR-Akt signaling pathway. The EGFR inhibitor AG1478 enhanced autophagic flux, and Akt inhibitor IV increased LC3 accumulation and inhibited C. parvum proliferation in HCT-8 cells. Akt inhibitor IV-inhibited C. parvum proliferation was attenuated by E64d+pepA. In summary, C. parvum could maintain intracellular survival by inhibiting autophagy via EGFR-PI3K/Akt pathway. These results revealed a new mechanism for the interaction of C. parvum with host cells.

Development of duplex real-time PCR for quick detection of cryptosporidiosis in goats

Cryptosporidium spp. is the most important foodborne and waterborne pathogens and a leading cause of mortality from foodborne and waterborne gastrointestinal diseases. In neonates of domestic animals, it is associated with consistent diarrhea and dehydration. Cryptosporidium infection begins with the ingestion of sporulated oocytes disseminated by carrier animals that consistently contaminate the environment. Many diagnostic tests are available including microscopy and antigen trap-ELISA, but none of the diagnostic tests available currently cannot differentiate between active and passive infection in the host. In the current study, to address this challenge an mRNA-based duplex TaqMan® probe PCR was developed to target the Cryptosporidium oocyst wall protein gene and 18SSU rRNA gene in a single tube that can detect metabolically active cryptosporidial oocysts. The mRNA transcripts are the direct indicator of any actively replicating cell and they will help decipher the active stages of its lifecycle in a host. This diagnostic assay was standardized by computing transcript copy number-based limit of detection (LOD). For COWP and 18SSU rRNA genes, the LOD was 7.08 × 10⁰⁴ and 5.95 × 10⁰⁵ , respectively. During active infections, the oocyst wall protein will be active and so its COWP gene transcripts will act as a marker for active infection. While transcripts for 18SSU rRNA are constitutively expressed in cryptosporidial life cycle. This current diagnostic assay will be a quantitative marker that will help assess the active stages of Cryptosporidium infection in neonates. The disease dynamics will help better understand to formulate the control strategies and contain infection among healthy animals.

Evaluation of a vaccine candidate isolated from Cryptosporidium parvum oocyst in mice

Background and Aim

Cryptosporidiosis is a leading cause of diarrheal disease worldwide and is an animal and public health burden. This study aimed to evaluate the protective potential of affinity-purified Cryptosporidium parvum oocyst antigen as a vaccine candidate according to fecal oocyst shedding, humoral and cellular immune responses, histopathological changes, and the number of parasite developmental stages in ileal and hepatic tissues.

Materials and Methods

We isolated oocysts from naturally infected buffalo calves and identified them molecularly as C. parvum isolates (GenBank: ON730707 and ON730708) by targeting the Cryptosporidium oocyst wall protein gene. We propagated the C. parvum oocysts in mice. In addition, we prepared crude antigen from the isolated oocysts by purification using cyanogen bromide-activated Sepharose-4B affinity chromatography coupled with rabbit hyperimmune serum. Then, we divided 81 parasite-free mice into three groups: (1) non-vaccinated non-infected mice, (2) mice orally infected with 1 × 10⁵ C. parvum oocysts on week 4 of the experiment, and (3) mice immunized twice with 40 μg/kg of the purified fraction at 2-week intervals. Then, we challenged the vaccinated group with C. parvum oocysts after 2 weeks, and the positive control group was infected at the same time.

Results

We observed a prolonged prepatent period and decreased oocyst shedding in the vaccinated infected mice compared with the non-vaccinated infected mice (t < 0.001). The vaccinated mice had significantly higher immunoglobulin G levels than those in the other two groups at all examined weeks. In addition, the production of cytokines interferon-gamma, interleukin (IL)-10, IL-12, and IL-15 was activated post-vaccination. After the challenge, all tested cytokines were significantly increased (p < 0.001) in the two infected groups compared with the non-vaccinated non-infected group, with the highest levels in the vaccinated infected group. Vaccinated infected mice exhibited significantly fewer pathological lesions in the ileum and liver than non-vaccinated infected mice, which showed prominent histopathological lesions. Endogenous developmental stages of C. parvum indicated that the ileum was more parasitized than the liver and that vaccination resulted in a lower number of oocysts in ileal and hepatic tissues (p < 0.05).

Conclusion

Our prepared affinity-purified vaccine candidate could be promising in protecting against cryptosporidiosis.

Prevalence and Molecular Epidemiology of Cryptosporidium Infection in Clarias gariepinus Fish in Egypt

PURPOSE

This study investigated the prevalence and molecular detection of Cryptosporidium spp. in catfish (Clarias gariepinus).

METHODS

A total of 300 Carias gariepinus fish were collected from two freshwater sources: the Nile River (180) and drainage canals (120). The stomach and intestine epithelium of each individual fish sample were screened by modified Ziehl-Neelsen (mZN) staining technique for the detection of Cryptosporidium oocysts followed by the serological survey for detection of Cryptosporidium antibodies using Enzyme-Linked Immunosorbent Assay (ELISA) and molecular characterization using complemented DNA polymerase chain reaction (cPCR).

RESULTS

ELISA showed higher prevalence of 69.3% than that prevalence obtained by mZN, 64% for the total examined Clarias gariepinus fish. Also, higher prevalence of Cryptosporidium infection 65.5% and 75.8% obtained by ELISA than 61.1% and 68.3% by mZN, in both fish groups from Nile River and Drainage canal, respectively. PCR analysis revealed the expected positive bands at 1056 bp. DNA sequencing and phylogenetic analysis proved that the positive-PCR Cryptosporidium isolate identified in the present study was Cryptosporidium molnari.

CONCLUSION

Freshwater fishes (Clarias gariepinus) are subjected to a high infection rate with Cryptosporidium spp.; the drainage canals obtained fishes showed higher prevalence than that collected from Nile River which indicates an important public health problem and a potential risk of drainage canals in Egypt. ELISA showed higher prevalence of cryptosporidiosis than mZN, for the total examined Clarias gariepinus fish and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium molnari.

The Protective Effect of Artemisia spicigera Ethanolic Extract against Cryptosporidium parvum Infection in Immunosuppressed Mice

Background

A specific treatment has not yet developed for cryptosporidiosis, and some of the used drugs had side effects in immunodeficient patients. The goal of an appropriate remedy is to remove symptoms and improve immune responses in hosts. The current study was designed to evaluate the therapeutic efficacy of Artemisia spicigera ethanolic extract in experimentally infected immunosuppressed mice.

Methods

Thirty six NMRI mice, 4-6 wk old, were randomly divided into six equal groups. C1: uninfected, treated control; C2: infected, untreated control; T1, T2, T3, and P: infected, treated with 0.2, 2, and 20 mg/ml extract, and 5mg/ml paromomycin, respectively. Mice were experimentally infected by oral administration of 10⁴ oocysts/animal of Cryptosporidium parvum and treated orally for eight days per 12h, starting 12h before experimental infection. The presence of oocyst shedding, weight gain/loss, and the histopathology of ileum sections were examined.

Results

Results revealed that oocyst shedding was significantly (P<0.05) reduced in treatment groups. There was no significant difference between the mean of weight gain/loss in the infected control and treated groups. Histopathological analysis of ileum sections further supported the parasitological findings.

Conclusion

Artemisia spicigera had acceptable efficacy as a therapeutic agent for cryptosporidiosis.

Effect of dexamethasone on experimental enteritis produced by Giardia lamblia in a Meriones unguiculatus model

Our aim was to evaluate the impact of immunosuppression on the development of giardiasis. Thirty-six gerbils (4-6 weeks old) were distributed in four groups containing nine animals each: Control (CT); Control-Infected by Giardia lamblia (CTIn), Immunosuppressed (IS), and Immunosuppressed-Infected by G. lamblia (ISIn). Animals in the IS and ISIn groups received intramuscular dexamethasone solution for 25 days. On the 11th day, the animals in the CTIn and ISIn groups were inoculated with G. lamblia. After 14 days of infection, the 25th day of the experiment, all groups were euthanized. Four hours after euthanasia, the intestinal permeability was evaluated and sections of the duodenum and spleen were harvested for morphometric and histopathological analyses. Immunosuppressed groups showed a significant increase in intestinal permeability compared to control and infected groups. Considering that the infection can become chronic in immunosuppressed groups, we should be alert to the possibilities of chronic inflammatory changes, both locally and systemically, due to the loss of the intestinal barrier. Lesions were observed in the duodenal mucosa of the gerbils of the CTIn group, with reduced villi size, crypt hyperplasia, edema, and the presence of inflammatory infiltrate in the lamina propria. In the ISIn group, we observed no inflammation, long and intact villi, and a significant increase in the area of intestinal mucins, despite the large number of trophozoites identified. Our results suggest that exacerbation of the immune response has a direct relationship with the appearance of lesions during enteritis produced by G. lamblia in the assessed model.

Outside the Box: Working With Wildlife in Biocontainment

Research with captive wildlife in Animal Biosafety Level 2 (ABSL2) and 3 (ABSL3) facilities is becoming increasingly necessary as emerging and re-emerging diseases involving wildlife have increasing impacts on human, animal, and environmental health. Utilizing wildlife species in a research facility often requires outside the box thinking with specialized knowledge, practices, facilities, and equipment. The USGS National Wildlife Health Center (NWHC) houses an ABSL3 facility dedicated to understanding wildlife diseases and developing tools to mitigate their impacts on animal and human health. This review presents considerations for utilizing captive wildlife for infectious disease studies, including, husbandry, animal welfare, veterinary care, and biosafety. Examples are drawn from primary literature review and collective 40-year experience of the NWHC. Working with wildlife in ABSL2 and ABSL3 facilities differs from laboratory animals in that typical laboratory housing systems, husbandry practices, and biosafety practices are not designed for work with wildlife. This requires thoughtful adaptation of standard equipment and practices, invention of customized solutions and development of appropriate enrichment plans using the natural history of the species and the microbiological characteristics of introduced and native pathogens. Ultimately, this task requires critical risk assessment, understanding of the physical and psychological needs of diverse species, creativity, innovation, and flexibility. Finally, continual reassessment and improvement are imperative in this constantly changing specialty area of infectious disease and environmental hazard research.

Cryptosporidium and cryptosporidiosis in wild birds: A One Health perspective

Cryptosporidium is one of the most important parasitic protozoa that can be transmitted through food and water contamination. With the increasing report of Cryptosporidium infections in wild birds, especially in herbivorous waterfowl, concerns have been raised for oocyst contamination of water and food supplies, which in turn can cause human and domestic animal infections in areas neighboring wild birds' habitats. This review discusses the epidemiology, species, and genotypes distribution of Cryptosporidium in wild birds around the world. The overall prevalence of Cryptosporidium in wild birds was calculated as 3.96% (1945/49129), with 6 Cryptosporidium species (C. andersoni, C. parvum, C. meleagridis, C. avium, C. baileyi, and C. galli) and 5 genotypes (Goose genotype I, Goose genotype II, Avian genotype I, Avian genotype III, and Avian genotype VI) reported. As wild birds mainly live in the wild, control method for the Cryptosporidium infection in wild birds is still lacking, which increases the probability of disease transmission from wild birds to humans. The main purpose of this review is to highlight the Cryptosporidium infection in wild birds and its transmission, associated risk factors, and their prevention, illustrating the necessity of multidisciplinary approaches toward screening and control of Cryptosporidium infections.

Cryptosporidium spp. infections in livestock and wild animals in Azerbaijan territory

Cryptosporidium is an intracellular protozoan parasite, globally distributed and capable of infecting various vertebrate species, including humans as well as domestic and wild animals. Cryptosporidium is increasingly gaining attention as a human and an animal pathogen mainly due to its dominant involvement in worldwide waterborne outbreaks. The present paper reviews the current knowledge and understanding of Cryptosporidium spp. in terrestrial and water animals in Azerbaijan.

Cryptosporidium in fish: Implications for aquaculture and beyond

Aquaculture industries are expanding worldwide and control of Cryptosporidium is of great importance. Cryptosporidiosis is a serious waterborne/foodborne disease, responsible for infectious outbreaks globally. Current knowledge on the Cryptosporidium species in the aquatic environment and their occurrence in piscine hosts is steadily increasing since the Cryptosporidium species have been detected in marine, freshwater, cultured, captive and ornamental fish in a wide range of geographical regions. The zoonotic potential of these parasites and their pathological impact on piscine hosts have been increasingly reported and the fishborne zoonotic risk from Cryptosporidium spp. is of major importance from a public health point of view. Zoonotic subtypes in fish have been described in various studies and are probably related to water contamination from animal and human wastes. This review critically evaluated existing scientific data, related to Cryptosporidium species in piscine hosts, emphasizing transmission routes and the potential impact of piscine cryptosporidiosis in aquaculture. This knowledge will facilitate consumers, authorities and water industries such as fisheries and aquaculture, the prevention and control of waterborne and fishborne cryptosporidiosis in fish products.

Molecular detection of Cryptosporidium: an emerging parasite in different water sources of 2010 flood-affected district Nowshera, Pakistan

Cryptosporidium is a water-borne zoonotic parasite worldwide, usually found in lakes and rivers contaminated with sewage and animal wastes, causing outbreaks of cryptosporidiosis. In this study, 300 water samples were collected from four designated places of flood-affected district Nowshera consist of different water sources to find out the prevalence of Cryptosporidium via polymerase chain reaction (PCR). The overall prevalence of Cryptosporidium was 30.33% (91/300) with more prevalent 44% in drain water and low 5% in bore/tube well water. The prevalence in open well and tap water was recorded 33% and 20%, respectively. The highest prevalence was recorded in summer (June-September). The result of this study ensures enormous contamination of drinking water that requires appropriate treatment, cleaning and filtration to provide safe drinking water. Preventing water-borne disease and proper treatment of water supplies is essential to public health.

Evolving Patterns of Cryptosporidiosis: Issues and Implications in the Context of Public Health in India

Cryptosporidiosis is one of the major causes of diarrhea in immune-compromised individuals and children besides causing sporadic water-borne, food-borne, and zoonotic outbreaks. In 2016, Cryptosporidium species infection was the fifth leading cause of diarrhea and acute infection causing more than 4.2 million disability-adjusted life years lost besides a decrease in childhood growth. Human cryptosporidiosis is primarily caused by two species/genotype: Cryptosporidium hominis (anthroponotic) and Cryptosporidium parvum (zoonotic) besides other six rare species/genotypes. Transmission intensity, genetic diversity, and occurrence of genetic recombination have shaped the genus Cryptosporidium population structures into palmitic, clonal, and epidemic. Genetic recombination is more in C. parvum compared with C. hominis. Furthermore, parasite–host co-evolution, host adaptation, and geographic segregation have led to the formation of “subtype- families.” Host-adapted subtype-families have distinct geographical distribution and host preferences. Genetic exchanges between subtypes played an important role throughout the evolution of the genus leading to “adaptation introgression” that led to emergence of virulent and hyper-transmissible subtypes. The population structure of C. hominis in India appears to be more complex where both transmission intensity and genetic diversity are much higher. Further, study based on “molecular strain surveillance” has resulted newer insights into the epidemiology and transmission of cryptosporidiosis in India. The identification at the species and genotype levels is essential for the assessment of infection sources in humans and the public health potential of the parasite at large. The results of the study over three decades on cryptosporidiosis in India, in the absence of a national surveillance data, were analyzed highlighting current situation on epidemiology, genetic diversity, and distribution particularly among vulnerable population. Despite creditable efforts, there are still many areas need to be explored; therefore, the intent of this article is to facilitate future research approaches for mitigating the burden associated with this disease.

Prospect of microbial food borne diseases in Pakistan: a review

Nowadays food borne illness is most common in people due to their epidemic nature. These diseases affect the human digestive system through bacteria, viruses and parasites. The agents of illness are transmitted in our body through various types of food items, water and uncooked. Pathogens show drastic changes in immunosuppressant people. This review gives general insights to harmful microbial life. Pakistan is a developed country and because of its improper food management, a lot of gastrointestinal problems are noted in many patients. Bacteria are most common agents to spread diarrhoea, villi infection, constipation and dysenteric disease in human and induce the rejection of organ transplant. Enhancement of their lifestyle, properly cooked food should be used and to overcome the outbreak of the diseases.

Recombinant Expression And Indirect ELISA For COWP And HSP70 Proteins From Cryptosporidium andersoni

Cryptosporidium spp. infect cattle at a high rates, and reduce milk production. Cryptosporidiosis has caused economic losses for the dairy industry. Studies in Western countries have shown that Cryptosporidium can also infect humans. Therefore, the development of methods for the early detection of Cryptosporidium is an important public health objective. Total RNA isolated from C. andersoni was used as template for generating cDNA encoding the COWP and HSP70 proteins. The recombinant plasmid, pET-32a(+)-COWP-HSP70, was constructed by double digestion and subcloning. The expression of the three recombinant proteins was induced in Escherichia coli BL21 using isopropyl-β-D-thiogalactopyranoside. The antigenicity of the recombinant proteins was examined using western blotting and indirect ELISA. The identities of the COWP fusion protein (CFP), HSP70 fusion protein (HFP), and COWP-HSP70 fusion protein (CHFP) were confirmed by BLAST searches of known sequences in GenBank respectively. The ELISA and western blot analyses indicated that all three of the proteins were highly immunogenic and antigenic. An indirect ELISA method was developed using the three recombinant proteins as coating antigens for the analysis of 40 clinical samples. The results showed that CHFP was the best candidate antigen for clinical testing, with a detection rate of 100%, compared with general parasitological screening. Above of all, the recombinant CHFP protein represents the best candidate antigen among three ones for detecting anti-Cryptosporidium antibodies in clinical samples. The development of the indirect ELISA lays the foundation for further research in immunodiagnosis and disease prevention of cryptosporidiosis.

A review of Cryptosporidium spp. and their detection in water

Cryptosporidium spp. are one of the most important waterborne pathogens worldwide and a leading cause of mortality from waterborne gastrointestinal diseases. Detection of Cryptosporidium spp. in water can be very challenging due to their low numbers and the complexity of the water matrix. This review describes the biology of Cryptosporidium spp. and current methods used in their detection with a focus on C. parvum and C. hominis. Among the methods discussed and compared are microscopy, immunology-based methods using monoclonal antibodies, molecular methods including PCR (polymerase chain reaction)-based assays, and emerging aptamer-based methods. These methods have different capabilities and limitations, but one common challenge is the need for better sensitivity and specificity, particularly in the presence of contaminants. The application of DNA aptamers in the detection of Cryptosporidium spp. oocysts shows promise in overcoming these challenges, and there will likely be significant developments in aptamer-based sensors in the near future.

Copro-microscopical and immunological diagnosis of cryptosporidiosis in Egyptian buffalo-calves with special reference to their cytokine profiles

Cryptosporidiosis is considered to be one of the most devasting gastrointestinal diseases in calves. The aim of this study was to investigate Cryptosporidium parvum infection (C. parvum) in buffalo-calves with both copro-microscopic examination and enzyme linked immunosorbent assay (ELISA) using two C. parvum prepared antigens with regards to their cytokines profile; interferon- γ (IFN-γ), interleukin (IL)-12 and IL-14 to achieve a proper diagnosis. All collected buffalo- calves' fecal samples were examined by modified Ziehl-Neelsen staining technique. ELISA was performed to evaluate the diagnostic accuracy of the two C. parvum prepared antigens; crude whole oocyst (CWO) and crude sonicated oocyst (CSO) in detection of anti-C. parvum IgG in buffalo-calves' sera. As well, concentrations of INF-γ, IL-12 and IL-14 in the buffalo-calves' serum samples were estimated. The results revealed that the overall parasitological incidence of cryptosporidiosis was 40%. However, the serological diagnosis by ELISA assay showed 53.75% and 27.5% when using CWO and CSO antigen, respectively. Also, the diagnostic efficacy parameters of both antigens; CWO and CSO showed a significant high specificity (83.3%) achieved by CSO antigen and a high sensitivity (71.8%) by CWO antigen. The levels of INF-γ, IL-12 and IL-14 were significantly increased in positive Cryptosporidium infected group by both coprological and serological assays followed by the group which was positive for cryptosporidiosis by copro-microscopic examination only. The present study concluded that a combination of coprological and serological examination with reference to the cytokines profile is needed for proper diagnosis of cryptosporidiosis in buffalo-calves.

Molecular identification and phylogenetic analysis of Cryptosporidium, Hepatozoon and Spirometra in snakes from central China

Snakes are popular as food and traditional medicine in China. However, information about parasitic and bacterial infections in snakes from China is scarce. We investigated the prevalence of selected zoonotic agents including Cryptosporidium, Hepatozoon and Spirometra, in snakes in central China from June to October in 2018 by PCR amplification using parasite-specific primers. PCR amplification and DNA sequencing showed that 10.1% (15/149) of snakes were positive for Cryptosporidium spp., while 2.7% (4/149) were positive for Hepatozoon. Additionally, we found 36.9% (55/149) of snakes were infected with Spirometra erinaceieuropaei. The spargana burden per infected snake ranged from 1 to 26. BLAST and phylogenetic analysis of small subunit ribosomal RNA (SSU rRNA) gene and 60-kDa glycoprotein (gp60) gene showed that the parasites belonged to Cryptosporidium parvum genotype IIdA15G1, C. baileyi, C. serpentis and a Hepatozoon species. We conclude that intensively farmed snakes excrete C. parvum and C. baileyi oocysts due to ingestion of infected feeder animals, and that wild snakes in central China were commonly infected with S. erinaceieuropaei, suggesting that eating improperly cooked snakes could be risky to human health.

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Cryptosporidium parvum and C. baileyi were reported in farmed snakes in China for the first time.

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C. serpentis was detected for the first time in Ptyas dhumnades and Gloydius brevicaudus.

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A tentative new Hapatozoon species was first time recorded in wild Lycodon rufozonatus and G. brevicaudus.

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Spirometra erinaceieuropaei infection was found common in wild snakes from central China.

Identification of adaptive inhibitors of Cryptosporidium parvum fatty acyl-coenzyme A synthetase isoforms by virtual screening

Cryptosporidiosis is a significant cause of gastroenteritis in both humans and livestock in developing countries. The only FDA-approved drug available against the same is nitazoxanide, with questionable efficacy in malnourished children and immunocompromised patients. Recent in vitro studies have indicated the viability of Triacsin C as a potential drug candidate, which targets the parasite's long-chain fatty acyl coenzyme A synthetase enzyme (LC-FACS), a critical component of the fatty acid metabolism pathway. We have used this molecule as a baseline to propose more potent versions thereof. We have applied a combined approach of substructure replacement, literature search, and database screening to come up with 514 analogs of Triacsin C. A virtual screening protocol was carried out which lead us to identify a potential hit compound. This was further subjected to a 100-ns molecular dynamics simulation in complex to determine its stability and binding characteristics. After which, the ADME/tox properties were predicted to assess its viability as a drug. The molecule R134 was identified as the best hit due to its highest average binding affinity, stability in complex when subjected to MD simulations, and reasonable predicted ADMET (Absorption, Distribution, Metabolism, Excretion and Toxicity) properties comparable to those of the Triacsin C parent molecule. We have proposed R134 as a putative drug candidate against the Cryptosporidium parvum LC-FACS enzyme isoforms, following an in silico protocol. We hope the results will be helpful when planning future in vitro experiments for identifying drugs against Cryptosporidium.

Prevalence of Giardia and Cryptosporidium in young livestock and dogs in Magude District of Maputo Province, Mozambique

BACKGROUND

Giardia and Cryptosporidium species are significant zoonotic parasites of humans and domesticated animals.

OBJECTIVES

The study aimed to determine the prevalence of Giardia and Cryptosporidium in livestock and dogs of the Magude District.

METHOD

The flotation technique (Willis), modified Ziehl-Neelsen (mZN) and direct and indirect immunofluorescence (DIF and IIF) techniques were applied to determine the prevalence of Giardia and Cryptosporidium species in faecal samples of dog pups (156), goat kids (60) and calves (480) from the Magude District of Mozambique from February to September 2015.

RESULTS

Using Willis, IIF and DIF, the prevalence of Giardia in calves was 0%, 8.1%, and 6.0%; in dogs 0.6%, 8.3% and 5.7% and for goats 0% and 13.3% (IIF was not performed), respectively. The prevalence of Cryptosporidium in calves using Willis, mZN, IIF and DIF was 0%, 3.8%, 4.7% and 0.4% and in dogs 0%, 0.6%, 6.4% and 0.6%, respectively. The parasite was not detected in goats.

CONCLUSION

Results from the present study showed that IIF performed better diagnosis of Giardia and Cryptosporidium, and that the mZN can be used as an alternative for Cryptosporidium because of the high cost of IIF. There is a need for identification of genotypes or subtypes of these parasites through application of molecular techniques in order to determine their zoonotic potential, and we advocate a 'one health' approach in the control and prevention of these parasites.

Molecular epidemiology of Giardia and Cryptosporidium infections - What's new?

New information generated since 2016 from the application of molecular tools to infections with Giardia and Cryptosporidium is critically summarised. In the context of molecular epidemiology, nomenclature, taxonomy, in vitro culture, detection, zoonoses, population genetics and pathogenicity, are covered. Whole genome sequencing has had the greatest impact in the last three years. Future advances will provide a much better understanding of the zoonotic potential of both parasites, their diversity and how this is linked to pathogenesis in different hosts.

Cryptosporidium parvum-Infected Neonatal Mice Show Gut Microbiota Remodelling Using High-Throughput Sequencing Analysis: Preliminary Results

BACKGROUND

During the last decade, the scientific community has begun to investigate the composition and role of gut microbiota in normal health and disease. These studies have provided crucial information on the relationship between gut microflora composition and intestinal parasitic infection, and have demonstrated that many enteric pathogen infections are associated with altered gut microflora composition. In this study, we investigated the effects of Cryptosporidium parvum infection (zoonotic protozoan affecting a large range of vertebrates) on both qualitative and quantitative composition of gut microbiota in a CD-1 neonatal mouse model.

METHODS

5-day-old neonate mice were experimentally infected with 10⁵Cryptosporidium parvum Iowa oocysts by oesophageal gavage. The intestinal microbiota of both infected (Cp+) and uninfected (Cp-) mice groups was examined by high-throughput sequencing of the bacterial 16S rDNA gene V3-V4 hypervariable region.

RESULTS

The most consistent change in the microbiota composition of Cp+ mice was the increased proportion of bacterial communities belonging to the Phylum Bacteroidetes. In contrast, the microbiota of Cp- mice was associated with increased proportions of several Firmicutes and Actinobacteria phyla members.

CONCLUSION

For the first time, our study provides evidence of an association between cryptosporidial infection and gut dysbiosis, thus contributing valuable knowledge to the as-yet little-explored field of Cryptosporidium-microbiota interactions in a neonatal mouse model.

Prevalence and risk factors associated with Cryptosporidium spp. infection in local breed of dogs in Enugu State, Nigeria

Aims:

Cryptosporidiosis is an important zoonotic disease of major public and veterinary concern. The disease affects humans and a variety of animal species including the domestic dog. This study aimed to determine the prevalence and risk factors associated with Cryptosporidium spp. infection in local breed of dogs from different homes and those presented at veterinary hospitals and clinics in Enugu State, Nigeria.

Materials and Methods:

A total of 203 fresh fecal samples were collected from domestic dogs in six local government areas in Enugu State from February 2015 to August 2015. All the samples were examined using the formol-ether sedimentation method. Fecal smears were then stained by the modified Ziehl–Neelsen technique and examined under direct light microscopy.

Results:

A total of 74 (36.5%) dogs were infected with Cryptosporidium spp. oocysts. There was a strong association (p<0.05) between the presence of Cryptosporidium spp. oocysts and management practices. However, there was no statistically significant association (p>0.05) between the presence of Cryptosporidium spp. oocysts and age, sex, and fecal consistency.

Conclusion:

The findings of this work suggest that domestic dogs in Enugu State harbor and shed Cryptosporidium spp. oocysts in the environment, especially those managed semi-intensively. Such fecal shedding is particularly so and of greater zoonotic and epidemiological importance in animals that do not show clinical signs and therefore not treated. They, therefore, pose a greater public health risk, especially to immune-compromised humans and animals. Public education on the zoonotic implication of this protozoan infection is of paramount importance in Enugu State, in particular, and Nigeria, in general, considering the closeness of dogs and man.

Involvement of Cryptosporidium parvum Cdg7_FLc_1000 RNA in the Attenuation of Intestinal Epithelial Cell Migration via Trans-Suppression of Host Cell SMPD3

Intestinal infection by Cryptosporidium parvum causes inhibition of epithelial turnover, but underlying mechanisms are unclear. Previous studies demonstrate that a panel of parasite RNA transcripts of low protein-coding potential are delivered into infected epithelial cells. Using in vitro and in vivo models of intestinal cryptosporidiosis, we report here that host delivery of parasite Cdg7_FLc_1000 RNA results in inhibition of epithelial cell migration through suppression of the gene encoding sphingomyelinase 3 (SMPD3). Delivery of Cdg7_FLc_1000 into infected cells promotes the histone methyltransferase G9a-mediated H3K9 methylation in the SMPD3 locus. The DNA-binding transcriptional repressor, PR domain zinc finger protein 1, is required for the assembly of Cdg7_FLc_1000 into the G9a complex and associated with the enrichment of H3K9 methylation at the gene locus. Pathologically, nuclear transfer of Cryptosporidium parvum Cdg7_FLc_1000 RNA is involved in the attenuation of intestinal epithelial cell migration via trans-suppression of host cell SMPD3.

Public health risks associated with food-borne parasites

Parasites are important food‐borne pathogens. Their complex lifecycles, varied transmission routes, and prolonged periods between infection and symptoms mean that the public health burden and relative importance of different transmission routes are often difficult to assess. Furthermore, there are challenges in detection and diagnostics, and variations in reporting. A Europe‐focused ranking exercise, using multicriteria decision analysis, identified potentially food‐borne parasites of importance, and that are currently not routinely controlled in food. These are Cryptosporidium spp., Toxoplasma gondii and Echinococcus spp. Infection with these parasites in humans and animals, or their occurrence in food, is not notifiable in all Member States. This Opinion reviews current methods for detection, identification and tracing of these parasites in relevant foods, reviews literature on food‐borne pathways, examines information on their occurrence and persistence in foods, and investigates possible control measures along the food chain. The differences between these three parasites are substantial, but for all there is a paucity of well‐established, standardised, validated methods that can be applied across the range of relevant foods. Furthermore, the prolonged period between infection and clinical symptoms (from several days for Cryptosporidium to years for Echinococcus spp.) means that source attribution studies are very difficult. Nevertheless, our knowledge of the domestic animal lifecycle (involving dogs and livestock) for Echinoccocus granulosus means that this parasite is controllable. For Echinococcus multilocularis, for which the lifecycle involves wildlife (foxes and rodents), control would be expensive and complicated, but could be achieved in targeted areas with sufficient commitment and resources. Quantitative risk assessments have been described for Toxoplasma in meat. However, for T. gondii and Cryptosporidium as faecal contaminants, development of validated detection methods, including survival/infectivity assays and consensus molecular typing protocols, are required for the development of quantitative risk assessments and efficient control measures.

Molecular Detection of Cryptosporidium Species in Domestic Ducks Sold for Food in Nigerian Live Bird Markets

Cryptosporidium infections has been reported in several avian species including chickens, pigeons and game birds where these infections had been identified to cause either enteric or respiratory diseases. However, little data exists on the molecular characterization of Cryptosporidium species in ducks, especially those in frequent contact with humans. The aim of this study was to detect the Cryptosporidium species infecting domestic ducks in two major live bird markets. A total of 109 fresh faecal samples were collected from all the ducks available on sale in the two markets. The detection of Cryptosporidium species was conducted by microscopy. All positive samples were confirmed by the nested PCR amplification and the nucleotide sequencing of the 18S rRNA genes. The results demonstrated that the prevalence of Cryptosporidium infection in ducks using microscopy was 11.0 % (12/109). There was a higher prevalence 14.0 % (7/50) in ducks from Ibadan compared with those 8.5 % (5/59) obtained from Oyo town. All positive samples by microscopy were also positive using the nested PCR and the DNA sequencing of the secondary PCR products from the 18S rRNA genes which revealed the presence of Cryptosporidium parvum. This study revealed that natural infections of C. parvum may occur in ducks in close contact with humans and other domestic animals and therefore suggests that cryptosporidiosis in ducks may be of public health importance.

Efficacy of chitosan, a natural polysaccharide, against Cryptosporidium parvum in vitro and in vivo in neonatal mice

Cryptosporidiosis is a zoonotic disease caused by species in the genus Cryptosporidium. In young ruminants, Cryptosporidium parvum causes economically significant disease with mild to severe clinical signs and occasional death. The typical clinical course in animals aged 1-3 weeks old is acute diarrhoea. Currently there are no available treatments that are fully effective against cryptosporidiosis in either humans or animals. Therefore there is a critical need for the development of new therapeutic agents. We adapted two in vitro culture systems (HCT-8 and Caco-2 cell lines) for C. parvum infection to investigate the "anticryptosporidial" activity of two chitosans; Chitosan NAG and Chitosan Mix. Chitosan-a naturally-occurring polysaccharide compound-has been found to be active against a variety of diseases, possessing both antimicrobial and anticancer properties. We investigated both chitosan's toxicity and effects on C. parvum in the two in vitro models. To evaluate chitosan's effects on oocyst shedding in vivo, CD-1 neonate mice were orally inoculated with C. parvum oocysts (Iowa strain), treated with chitosan, and compared to infected non-treated animals. Paromomycin, a classical drug used in veterinary medicine, was used as a reference compound. Immunofluorescence techniques were used to analyse the parasites. Our results showed significant reductions in Cryptosporidium oocyst viability (>95%) after oocyst pre-incubation with either paromomycin (P < 0.001), Chitosan Mix or Chitosan NAG (P < 0.001), for 24 h at 37 °C. Additionally, paromomycin, Chitosan Mix, and Chitosan NAG significantly inhibited C. parvum multiplication in HCT-8 and Caco-2 cell lines (P < 0.005). These effects were dose-dependent. In in vivo studies, treatment with both chitosans (Chitosan NAG, Chitosan Mix) or paromomycin sulfate significantly reduced parasite shedding in infected treated newborn mice (-56%, -34.5% and -58%, respectively). In conclusion, these findings provide the first in vitro and in vivo evidence of the anticryptosporidial activities of this natural polysaccharide.

Attenuation of Intestinal Epithelial Cell Migration During Cryptosporidium parvum Infection Involves Parasite Cdg7_FLc_1030 RNA-Mediated Induction and Release of Dickkopf-1

Intestinal infection by Cryptosporidium is known to cause epithelial cell migration disorder but the underlying mechanisms are unclear. Previous studies demonstrated that a panel of parasite RNA transcripts of low protein-coding potential are delivered into infected epithelial cells. Using multiple models of intestinal cryptosporidiosis, we report here that C. parvum infection induces expression and release of the dickkopf protein 1 (Dkk1) from intestinal epithelial cells. Delivery of parasite Cdg7_FLc_1030 RNA to intestinal epithelial cells triggers transactivation of host Dkk1 gene during C. parvum infection. Release of Dkk1 is involved in C. parvum-induced inhibition of cell migration of epithelial cells, including noninfected bystander cells. Moreover, Dkk1-mediated suppression of host cell migration during C. parvum infection involves inhibition of Cdc42/Par6 signaling. Our data support the hypothesis that attenuation of intestinal epithelial cell migration during Cryptosporidium infection involves parasite Cdg7_FLc_1030 RNA-mediated induction and release of Dkk1 from infected cells.

In-silico screening of small molecule inhibitors against Lactate Dehydrogenase (LDH) of Cryptosporidium parvum

Cryptosporidium parvum is a protozoan parasite which causes waterborne diseases known as Cryptosporidiosis. It is an acute enteric diarrheal disease being severe in the case of immunocompromised individuals and children. C. parvum mainly depends on the glycolysis process for energy production and LDH (Lactate Dehydrogenase) is a key controller of this process. In this study from different in-silico approaches such as structure-based, ligand-based and de novo drug design; a total of 40 compounds were selected for docking studies against LDH. The study reported a compound CHEMBL1784973 from Pathogen Box as the best inhibitor in terms of docking score and pharmacophoric features. Furthermore, the binding mode of the best-reported inhibitor was validated through molecular dynamics simulation for a time interval of 70 ns in water environment. The findings resulted in the stable conformation of the inhibitor in the active site of the protein. This study will be helpful for experimental validation.

Limitations in the screening of potentially anti-cryptosporidial agents using laboratory rodents with gastric cryptosporidiosis

The emergence of cryptosporidiosis, a zoonotic disease of the gastrointestinal and respiratory tract caused by Cryptosporidium Tyzzer, 1907, triggered numerous screening studies of various compounds for potential anti-cryptosporidial activity, the majority of which proved ineffective. Extracts of Indonesian plants, Piper betle and Diospyros sumatrana, were tested for potential anti-cryptosporidial activity using Mastomys coucha (Smith), experimentally inoculated with Cryptosporidium proliferans Kváč, Havrdová, Hlásková, Daňková, Kanděra, Ježková, Vítovec, Sak, Ortega, Xiao, Modrý, Chelladurai, Prantlová et McEvoy, 2016. None of the plant extracts tested showed significant activity against cryptosporidia; however, the results indicate that the following issues should be addressed in similar experimental studies. The monitoring of oocyst shedding during the entire experimental trial, supplemented with histological examination of affected gastric tissue at the time of treatment termination, revealed that similar studies are generally unreliable if evaluations of drug efficacy are based exclusively on oocyst shedding. Moreover, the reduction of oocyst shedding did not guarantee the eradication of cryptosporidia in treated individuals. For treatment trials performed on experimentally inoculated laboratory rodents, only animals in the advanced phase of cryptosporidiosis should be used for the correct interpretation of pathological alterations observed in affected tissue. All the solvents used (methanol, methanol-tetrahydrofuran and dimethylsulfoxid) were shown to be suitable for these studies, i.e. they did not exhibit negative effects on the subjects. The halofuginone lactate, routinely administered in intestinal cryptosporidiosis in calves, was shown to be ineffective against gastric cryptosporidiosis in mice caused by C. proliferans. In contrast, the control application of extract Arabidopsis thaliana, from which we had expected a neutral effect, turned out to have some positive impact on affected gastric tissue.

Genomics and molecular epidemiology of Cryptosporidium species

Cryptosporidium is one of the most widespread protozoan parasites that infects domestic and wild animals and is considered the second major cause of diarrhea and death in children after rotavirus. So far, around 20 distinct species are known to cause severe to moderate infections in humans, of which Cryptosporidium hominis and Cryptosporidium parvum are the major causative agents. Currently, ssurRNA and gp60 are used as the optimal markers for differentiating species and subtypes respectively. Over the last decade, diagnostic tools to detect and differentiate Cryptosporidium species at the genotype and subtype level have improved, but our understanding of the zoonotic and anthroponotic transmission potential of each species is less clear, largely because of the paucity of high resolution whole genome sequencing data for the different species. Defining which species possess an anthroponotic vs. zoonotic transmission cycle is critical if we are to limit the spread of disease between animals and humans. Likewise, it is unclear to what extent genetic hybridization impacts disease potential or the emergence of outbreak strains. The development of high resolution genetic markers and whole genome sequencing of different species should provide new insights into these knowledge gaps. The aim of this review is to outline currently available molecular epidemiology and genomics data for different species of Cryptosporidium.

Cryptosporidiosis: A zoonotic disease concern

Cryptosporidiosis is considered to be a crucial zoonotic disease caused by worldwide distributing parasitic protozoa called Cryptosporidium spp. Cryptosporidiosis becomes a major public health and veterinary concern by affecting in human and various host range species of animals. Essentially, its importance of infection is increasing because of the high incidence in young children, immunocompromised persons, or immunodeficiency syndrome patients, especially in HIV/AIDS, and it is also one of the most causes of mortality in those patients who infected with Cryptosporidium spp. as well as young animals. All domestic animal, livestock, wildlife, and human can be potential reservoirs that contribute Cryptosporidium spp. to food and surface waters and transmitted to other hosts through fecal-oral route. The oocyst stage of Cryptosporidium spp. can remain infective and resistant to various environmental exposure and also resistant to many general disinfecting agents including chlorination which normally used in water treatment. Therefore, the understanding of these zoonotic pathogens is very essential in both animal and human health. This review focuses on the biology, life cycle, transmission, diagnosis, treatment, prevention, and control of this protozoan infection to emphasize and remind as the significant One Health problem.

Cryptosporidiosis Outbreak in Immunocompetent Children from a Remote Area of French Guiana

In September 2014, an increase in the number of Cryptosporidium spp. gastrointestinal tract infections was reported over a 6-month period among children living in a remote area along the Maroni River in French Guiana. Children presented gastroenteritis symptoms with Cryptosporidium-positive stools. Questionnaires were administered and stool examinations were controlled 3 months after the onset of symptoms. Data collection included demographics, food consumption, river behavior, symptoms, and outcome. Stool specimens were tested using microscopy and polymerase chain reaction. Samples from the water systems were examined for turbidity and culture for bacteria. Data from the reference laboratory were analyzed to calculate the median cryptosporidiosis incidence among immunocompetent patients from 2008 to 2015. Data on gastroenteritis cases reported by the Delocalized Center for Prevention and Care in the area were also collected. We report a cluster of 14 cases. All cases were children, aged between 4.5 and 38 months. Seven reported moderate to severe dehydration and required hospitalization. Speciation and microbiological typing revealed the cluster strain was Cryptosporidium hominis subtype IbA10G2 but C. hominis IbA9G2 and IbA15G1 strains were also identified. The median incidence in French Guiana was 5.8 cases per year before the outbreak. The first cases of the cluster appeared in the dry season. We describe the clinical features, epidemiology, and state of current investigations for the largest documented outbreak of cryptosporidiosis in French Guiana.

Risk factors and infection due to Cryptosporidium spp. in dogs and cats in southern Rio Grande do Sul

Abstract This study investigated the frequency of oocysts of Cryptosporidium spp. in feces from dogs and cats in five municipalities in the southern region of the state of Rio Grande do Sul. The risk factors associated with infection were also investigated. Feces samples from 110 dogs and 18 cats were stained using the auramine method. At the time of feces sampling, a questionnaire with semi-open-ended questions was applied to the animal guardians and all data obtained underwent statistical analysis. The real frequency of oocysts of Cryptosporidium spp. was 24.63% (27 dogs and two cats). Only four samples of dog feces were diarrheic and no presence of oocysts was observed in any of them. Variables that represented risk factors for infection were: homemade food, untreated water, circulation of animals on grassy terrain and living in the same environment as other animals (cattle). The results made it possible to inferring that within the population studied, the frequency of parasitism due to Cryptosporidium spp. in dogs was relevant and emphasize the asymptomatic nature of this infection. The adopting control measures are highlighted, particularly in relation to variables that represent risk factors for this infection.

Trans-suppression of host CDH3 and LOXL4 genes during Cryptosporidium parvum infection involves nuclear delivery of parasite Cdg7_FLc_1000 RNA

Intestinal infection by Cryptosporidium parvum causes significant alterations in the gene expression profile in host epithelial cells. Previous studies demonstrate that a panel of parasite RNA transcripts of low protein-coding potential are delivered into infected host cells and may modulate host gene transcription. Using in vitro models of human intestinal cryptosporidiosis, we report here that trans-suppression of the cadherin 3 (CDH3) and lysyl oxidase like 4 (LOXL4) genes in human intestinal epithelial cells following C. parvum infection involves host delivery of the Cdg7_FLc_1000 RNA, a C. parvum RNA that has been previously demonstrated to be delivered into the nuclei of infected host cells. Downregulation of CDH3 and LOXL4 genes was detected in host epithelial cells following C. parvum infection or in cells expressing the parasite Cdg7_FLc_1000 RNA. Knockdown of Cdg7_FLc_1000 attenuated the trans-suppression of CDH3 and LOXL4 genes in host cells induced by infection. Interestingly, Cdg7_FLc_1000 was detected to be recruited to the promoter regions of both CDH3 and LOXL4 gene loci in host cells following C. parvum infection. Host delivery of Cdg7_FLc_1000 promoted the PH domain zinc finger protein 1 (PRDM1)-mediated H3K9 methylation associated with trans-suppression in the CDH3 gene locus, but not the LOXL4 gene. Therefore, our data suggest that host delivery of Cdg7_FLc_1000 causes CDH3 trans-suppression in human intestinal epithelial cells following C. parvum infection through PRDM1-mediated H3K9 methylation in the CDH3 gene locus, whereas Cdg7_FLc_1000 induces trans-suppression of the host LOXL4 gene through H3K9/H3K27 methylation-independent mechanisms.

Trans-suppression of defense DEFB1 gene in intestinal epithelial cells following Cryptosporidium parvum infection is associated with host delivery of parasite Cdg7_FLc_1000 RNA

To counteract host immunity, Cryptosporidium parvum has evolved multiple strategies to suppress host antimicrobial defense. One such strategy is to reduce the production of the antimicrobial peptide beta-defensin 1 (DEFB1) by host epithelial cells but the underlying mechanisms remain unclear. Recent studies demonstrate that a panel of parasite RNA transcripts of low protein-coding potential are delivered into infected host cells and may modulate host gene transcription. Using in vitro models of intestinal cryptosporidiosis, in this study, we analyzed the expression profile of host beta-defensin genes in host cells following infection. We found that C. parvum infection caused a significant downregulation of the DEFB1 gene. Interestingly, downregulation of DEFB1 gene was associated with host delivery of Cdg7_FLc_1000 RNA transcript, a C. parvum RNA that has previously demonstrated to be delivered into the nuclei of infected host cells. Knockdown of Cdg7_FLc_1000 in host cells could attenuate the trans-suppression of host DEFB1 gene and decreased the parasite burden. Therefore, our data suggest that trans-suppression of DEFB1 gene in intestinal epithelial cells following C. parvum infection involves host delivery of parasite Cdg7_FLc_1000 RNA, a process that may be relevant to the epithelial defense evasion by C. parvum at the early stage of infection.

Nuclear delivery of parasite Cdg2_FLc_0220 RNA transcript to epithelial cells during Cryptosporidium parvum infection modulates host gene transcription

Intestinal infection by the zoonotic protozoan, Cryptosporidium parvum, causes significant alterations in the gene expression profile in host epithelial cells. The molecular mechanisms of how C. parvum may modulate host cell gene transcription and the pathological significance of such alterations are largely unclear. Previous studies demonstrate that a panel of parasite RNA transcripts are delivered into infected host cells and may modulate host gene transcription. Using in vitro models of intestinal cryptosporidiosis, in this study, we analyzed the impact of host delivery of C. parvum Cdg2_FLc_0220 RNA transcript on host gene expression profile. We found that alterations in host gene expression profile following C. parvum infection were partially associated with the nuclear delivery of Cdg2_FLc_0220. Specifically, we identified a total of 46 overlapping upregulated genes and 8 overlapping downregulated genes in infected cells and cells transfected with Full-Cdg2_FLc_0220. Trans-suppression of the DAZ interacting zinc finger protein 1 like (DZIP1L) gene, the top overlapping downregulated gene in host cells following C. parvum infection and cells transfected with Full-Cdg2_FLc_0220, was mediated by G9a, independent of PRDM1. Cdg2_FLc_0220-mediated trans-suppression of the DZIP1L gene was independent of H3K9 and H3K27 methylation. Data from this study provide additional evidence that delivery of C. parvum Cdg2_FLc_0220 RNA transcript in infected epithelial cells modulates the transcription of host genes, contributing to the alterations in the gene expression profile in host epithelial cells during C. parvum infection.

Cryptosporidium in humans and animals-a one health approach to prophylaxis

Cryptosporidium is a major cause of moderate-to-severe diarrhoea in humans worldwide, second only to rotavirus. Due to the wide host range and environmental persistence of this parasite, cryptosporidiosis can be zoonotic and associated with foodborne and waterborne outbreaks. Currently, 31 species are recognized as valid, and of these, Cryptosporidium hominis and Cryptosporidium parvum are responsible for the majority of infections in humans. The immune status of the host, both innate and adaptive immunity, has a major impact on the severity of the disease and its prognosis. Immunocompetent individuals typically experience self-limiting diarrhoea and transient gastroenteritis lasting up to 2 weeks and recover without treatment, suggesting an efficient host antiparasite immune response. Immunocompromised individuals can suffer from intractable diarrhoea, which can be fatal. Effective drug treatments and vaccines are not yet available. As a result of this, the close cooperation and interaction between veterinarians, health physicians, environmental managers and public health operators is essential to properly control this disease. This review focuses on a One Health approach to prophylaxis, including the importance of understanding transmission routes for zoonotic Cryptosporidium species, improved sanitation and better risk management, improved detection, diagnosis and treatment and the prospect of an effective anticryptosporidial vaccine.

Cryptosporidium and cryptosporidiosis: The Asian perspective

This review discusses findings of Cryptosporidium and cryptosporidiosis research in Asia and highlights the current situation of Cryptosporidium epidemiology, genetic diversity and distribution, and transmission throughout Asia taking into account all the available papers published for Cryptosporidium research in Asian countries since 2000. This effort will facilitate future research approaches and further developments in the understanding of Cryptosporidium epidemiology in Asia. The intent is to contribute to improvement in protection measures for mitigating the burden associated with this illness in the future.