Cryptosporidiosis and Cryptosporidium species in animals and humans: a thirty colour rainbow?

Prevalence and Molecular Characterization of Cryptosporidium Species in Diarrheic Children in Cameroon

Cryptosporidiosis remains a major cause of diarrhea-related childhood death, particularly in developing countries. Although effective anti-retroviral therapy has significantly reduced the cryptosporidiosis burden in western nations, the situation in developing countries remains alarming due to limited therapeutic options and a lack of preventive measures. To better control disease transmission and develop effective prevention strategies, a thorough understanding of the genetic diversity of circulating species is crucial. While cryptosporidiosis has previously been reported in Cameroon, information on the genetic diversity of parasite strains is lacking. In a large cross-sectional study conducted between March 2020 and March 2021 in four regions of Cameroon, Southwest, Littoral, Center and West, a total of 1119 fecal samples of children (n = 1119) were collected and genetically analyzed. This study aimed to assess the genetic diversity of Cryptosporidium strains circulating in this patient cohort in Cameroon. Using modified Ziehl-Neelsen fecal smear staining, an overall prevalence of 8.5% (96/1119) was recorded. PCR analysis revealed a prevalence of 15.4% in the Center, 7.2% in the Littoral, 10.5% in the West, and 13.1% in the Southwest regions. Molecular analysis identified Cryptosporidium. hominis and Cryptosporidium parvum as circulating species, with all subtype families suggesting anthroponotic transmission. No zoonotic subtypes of C. parvum were detected. These findings confirm that cryptosporidiosis transmission in Cameroon is primarily anthroponotic. Nonetheless, much larger epidemiological surveys, including other patient cohorts, are necessary for final confirmation of this statement.

Prevalence and genotype analysis of Cryptosporidium spp. in nine species of wild rodents in China

Cryptosporidium is a significant zoonotic parasite with broad distribution in both humans and rodents. In this study, 510 fecal samples were collected from nine species of wild rodents across Guangxi, Yunnan, and Hunan Provinces in China. Nested PCR analysis targeting the SSU rRNA gene revealed an overall Cryptosporidium infection rate of 1.8% (9/510) among rodents in these provinces. The highest positivity rate was observed in Guangxi Province at 4.9% (5/103), followed by Yunnan Province (2.3%, 2/88), and Hunan Province (0.6%, 2/319). Notably, Rattus losea exhibited the highest prevalence rate at 9.8% (4/41), while Rattus flavipectus and Niviventer lotipes showed rates of 5.1% (2/39) and 4.4% (1/23), respectively. Various genotypes/species were identified, including Cryptosporidium viatorum, Cryptosporidium muris, Cryptosporidium vole genotype VII, and Cryptosporidium ratti, rat genotypes II, and IV. The study also found that wild rodents inhabiting mountainous areas had a higher prevalence rate at 4.9% (5/103) compared to those residing in fields and lake beaches, where prevalence rates were 2.1% (2/95) and 0.6% (2/312), respectively. This study provides new insights into Cryptosporidium infection rates among wild rodents and identifies two zoonotic species, C. viatorum and C. muris. These findings underscore the potential risk posed by Chinese wild rodent populations in transmitting zoonotic Cryptosporidium, which could significantly impact public health. Therefore, effective control strategies are needed to prevent transmission between humans and rodents.

Molecular characterization and zoonotic risk assessment of Cryptosporidium spp. in Philippine bats

Cryptosporidium is a genus of parasitic protozoa known to cause diarrheal disease that impacts both humans and animals through infection of various vertebrate species. Bats are recognized as reservoirs for zoonotic pathogens, including Cryptosporidium. The Philippines, renowned for its rich biodiversity, is home to diverse bat species, providing a unique ecological setting to investigate Cryptosporidium infection dynamics. Understanding the prevalence and genetic diversity of Cryptosporidium in Philippine bats is crucial for assessing their potential role in zoonotic disease transmission and associated public health risks. We investigated the prevalence and genotypic diversity of Cryptosporidium in bats in the Philippines. From January 2019 to March 2024, a total of 569 bats were captured and analyzed, with 14 of the bat samples testing positive for the 18 s rRNA gene of Cryptosporidium, yielding an overall infection rate of 2.46 %. One sample exhibited co-infection, with 18 s rRNA sequence analysis indicating mixed infection with a species closely related to Cryptosporidium parvum (intestinal Cryptosporidium) and Cryptosporidium sp. (gastric Cryptosporidium). Phylogenetic analysis of the 18S rRNA gene revealed that intestinal and gastric Cryptosporidium spp. form two distinct clades. Intestinal Cryptosporidium includes C. parvum, C. hominis, and most bat genotypes, while gastric Cryptosporidium, such as C. andersoni and C. serpentis, is typically found in reptiles and cattle. An unidentified Cryptosporidium species was also detected in one sample, whose sequence matched that of Cryptosporidium previously isolated from a human patient with diarrhea. Nine other samples exhibited genotypes related to C. parvum, indicating a potential for transmission to humans. The remaining three samples exhibited Cryptosporidium bat genotypes II and VI, which have previously been detected in Philippine bats. Our findings underscore the role of bats in the Philippines as potential reservoirs for Cryptosporidium and highlight the diversity of Cryptosporidium species in Philippine bats.

Coproantigen detection and molecular identification of Cryptosporidium species among newborn and adult farm animals

Cryptosporidium sp. is an obligatory intracellular apicomplexan protozoan parasite that causes a disease called cryptosporidiosis with substantial veterinary and medical importance. Therefore, this study aimed to evaluate an early diagnosis of cryptosporidiosis using the anti-Cryptosporidium parvum oocyst immunoglobulin IgG polyclonal antibodies (anti-C. parvum IgG PAbs)-based sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of Cryptosporidium oocyst antigens in fecal samples of farm animals in Egypt. Further molecular identification and sequencing were performed for the detected isolates. Eight hundred and twenty fecal samples of farm animals; 102 buffalo calves, 120 cattle calves, 100 lambs and 98 goat kids, 80 buffaloes, 60 cattle, 160 sheep and 100 goats, collected from different small-scale farms and local holders were examined for cryptosporidiosis by Modified Ziehl-Neelsen (MZN) technique. The percentage of positivity was 45.1%, 50%, 20%, 18.4%, 31.25%, 38.3%, 18.8%, and 11% in buffalo calves, cattle calves, lambs, goat kids, adult buffaloes, adult cattle, sheep, and goats, respectively. Molecular identification of Cryptosporidium samples was performed based on COWP gene, revealing the isolates: GenBank: OQ121955.1, OR029973.1 and PP316107.1 which were identical to the C. parvum and GenBank: PP316108.1 and OR029972.1 which were identical to C. hominis and C. andersoni, respectively. Then, C. parvum oocysts were used for preparation of antigens and rabbit immunization. Anti-C. parvum IgG PAbs were purified and characterized by SDS-PAGE and then labeled with horseradish peroxidase (HRP). Anti-C. parvum IgG PAbs in-house sandwich ELISA was prepared, then tested this ELISA on 820 samples and compared results with MZN microscopical examination and a commercial sandwich ELISA kit. In this study, in-house sandwich ELISA scored higher sensitivity of 98%, 100% specificity, validity 99% and relative agreement 98.6% than (92%, 90%, 91% and 91.4%) of MZN and (96%, 95%, 95.5% and 95.7%) of coproantigen commercial sandwich ELISA kit, respectively. Moreover, we used PCR to evaluate the positivity of in-house sandwich ELISA results, and the total PCR positive samples were 263 out of 268 sandwich ELISA positive samples (98.13%). In conclusion, the prepared Anti-C. parvum IgG PAbs based sandwich ELISA offered a simple and accurate diagnostic method for cryptosporidiosis in the fecal samples of different species of farm animals in Egypt with high sensitivity (98%) and specificity (100%). Further studies on this Anti-C. parvum IgG PAbs may help also in the protection against cryptosporidiosis.

Molecular Screening and Characterization of Enteric Protozoan Parasites and Microsporidia in Wild Ducks from Portugal

Enteric parasites pose significant threats to both human and veterinary health, ranking among the top causes of mortality worldwide. Wild migratory waterfowl, such as ducks, may serve as hosts and vectors for these parasites, facilitating their transmission across ecosystems. This study conducted a molecular screening of enteric parasites in three species of wild ducks of the genus Anas (A. acuta, A. platyrhynchos and A. crecca) from Portugal, targeting Blastocystis sp., Balantioides coli, Cryptosporidium spp., Encephalitozoon spp., and Enterocytozoon bieneusi. Fecal samples from 71 ducks were analyzed using PCR and sequencing techniques. The results revealed a 2.82% occurrence of Blastocystis sp. subtype 7 and Cryptosporidium baileyi, marking the first molecular detection of these pathogens in wild ducks in Portugal. While previous studies have documented these parasites in Anas spp. in other regions, this study contributes novel data specific to the Portuguese context. No evidence of Balantioides coli, Encephalitozoon spp. or Enterocytozoon bieneusi was found. These findings highlight the potential role of migratory ducks as vectors for zoonotic protozoa, emphasizing the need for enhanced surveillance of avian populations to mitigate cross-species transmission risks. Further research is warranted to understand the global public health implications associated with migratory waterfowl.

Assessment of pathogenic protozoa in a drinking water treatment plant with UV treatment

Controlling drinking water treatment processes is essential to address water contamination and the adaptability of certain pathogenic protozoa. Sometimes, standard treatment methods and chlorine disinfection may prove insufficient in eliminating pathogenic protozoa. However, ultraviolet (UV) radiation has proved to be more effective than chlorine. This study aims to characterize the eukaryotic community of a drinking water treatment plant that applies a final UV disinfection treatment, focusing on pathogenic protozoa. Fifty water samples (raw water, before and after UV treatment) were evaluated to comply with regulation parameters and identify relevant protozoa. Despite physicochemical and microbiological parameters meeting the regulation, some potentially pathogenic protozoa, such as Blastocystis or Cryptosporidium, were still detected in very low relative abundances in treated water. It was found for the first time in Spain the pathogenic amoebae Naegleria fowleri in one river water, which was not found after the treatment. Moreover, Blastocystis subtypes ST1-ST6 were detected in this study in raw, before and after UV water samples. Blastocystis was only found in 2 two samples after UV treatment, with a very low abundance (≤0.02%). Obtained results demonstrate the effectiveness of water treatment in reducing the prevalence of pathogenic protozoa.

WHOLE GENOME TARGETED ENRICHMENT AND SEQUENCING OF HUMAN-INFECTING CRYPTOSPORIDIUM spp

Cryptosporidium spp. are protozoan parasites that cause severe illness in vulnerable human populations. Obtaining pure Cryptosporidium DNA from clinical and environmental samples is challenging because the oocysts shed in contaminated feces are limited in quantity, difficult to purify efficiently, may derive from multiple species, and yield limited DNA (<40 fg/oocyst). Here, we develop and validate a set of 100,000 RNA baits (CryptoCap_100k) based on six human-infecting Cryptosporidium spp. ( C. cuniculus , C. hominis , C. meleagridis , C. parvum , C. tyzzeri , and C. viatorum ) to enrich Cryptosporidium spp. DNA from a wide array of samples. We demonstrate that CryptoCap_100k increases the percentage of reads mapping to target Cryptosporidium references in a wide variety of scenarios, increasing the depth and breadth of genome coverage, facilitating increased accuracy of detecting and analyzing species within a given sample, while simultaneously decreasing costs, thereby opening new opportunities to understand the complex biology of these important pathogens.

Genetic crosses within and between species of Cryptosporidium

Parasites and their hosts are engaged in reciprocal coevolution that balances competing mechanisms of virulence, resistance, and evasion. This often leads to host specificity, but genomic reassortment between different strains can enable parasites to jump host barriers and conquer new niches. In the apicomplexan parasite Cryptosporidium, genetic exchange has been hypothesized to play a prominent role in adaptation to humans. The sexual lifecycle of the parasite provides a potential mechanism for such exchange; however, the boundaries of Cryptosporidium sex are currently undefined. To explore this experimentally, we established a model for genetic crosses. Drug resistance was engineered using a mutated phenylalanyl tRNA synthetase gene and marking strains with this and the previously used Neo transgene enabled selection of recombinant progeny. This is highly efficient, and genomic recombination is evident and can be continuously monitored in real time by drug resistance, flow cytometry, and PCR mapping. Using this approach, multiple loci can now be modified with ease. We demonstrate that essential genes can be ablated by crossing a Cre recombinase driver strain with floxed strains. We further find that genetic crosses are also feasible between species. Crossing Cryptosporidium parvum, a parasite of cattle and humans, and Cryptosporidium tyzzeri a mouse parasite resulted in progeny with a recombinant genome derived from both species that continues to vigorously replicate sexually. These experiments have important fundamental and translational implications for the evolution of Cryptosporidium and open the door to reverse- and forward-genetic analysis of parasite biology and host specificity.

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.

Genetic crosses within and between species of Cryptosporidium

Parasites and their hosts are engaged in rapid coevolution that balances competing mechanisms of virulence, resistance, and evasion. This often leads to host specificity, but genomic reassortment between different strains can enable parasites to jump host barriers and conquer new niches. In the apicomplexan parasite Cryptosporidium genetic exchange has been hypothesized to play a prominent role in adaptation to humans. The sexual lifecycle of the parasite provides a potential mechanism for such exchange; however, the boundaries of Cryptosporidium sex are currently undefined. To explore this experimentally, we established a model for genetic crosses. Drug resistance was engineered using a mutated phenylalanyl tRNA synthetase gene and marking strains with this and the previously used Neo transgene enabled selection of recombinant progeny. This is highly efficient, and genomic recombination is evident and can be continuously monitored in real time by drug resistance, flow cytometry, and PCR mapping. Using this approach multiple loci can now be modified with ease. We demonstrate that essential genes can be ablated by crossing a Cre recombinase driver strain with floxed strains. We further find that genetic crosses are also feasible between species. Crossing C. parvum, a parasite of cattle and humans, and C. tyzzeri a mouse parasite resulted in progeny with a recombinant genome derived from both species that continues to vigorously replicate sexually. These experiments have important fundamental and translational implications for the evolution of Cryptosporidium and open the door to reverse- and forward- genetic analysis of parasite biology and host specificity.

Cryptosporidium mortiferum n. sp. (Apicomplexa: Cryptosporidiidae), the species causing lethal cryptosporidiosis in Eurasian red squirrels (Sciurus vulgaris)

BACKGROUND

Cryptosporidium spp. are globally distributed parasites that infect epithelial cells in the microvillus border of the gastrointestinal tract of all classes of vertebrates. Cryptosporidium chipmunk genotype I is a common parasite in North American tree squirrels. It was introduced into Europe with eastern gray squirrels and poses an infection risk to native European squirrel species, for which infection is fatal. In this study, the biology and genetic variability of different isolates of chipmunk genotype I were investigated.

METHODS

The genetic diversity of Cryptosporidium chipmunk genotype I was analyzed by PCR/sequencing of the SSU rRNA, actin, HSP70, COWP, TRAP-C1 and gp60 genes. The biology of chipmunk genotype I, including oocyst size, localization of the life cycle stages and pathology, was examined by light and electron microscopy and histology. Infectivity to Eurasian red squirrels and eastern gray squirrels was verified experimentally.

RESULTS

Phylogenic analyses at studied genes revealed that chipmunk genotype I is genetically distinct from other Cryptosporidium spp. No detectable infection occurred in chickens and guinea pigs experimentally inoculated with chipmunk genotype I, while in laboratory mice, ferrets, gerbils, Eurasian red squirrels and eastern gray squirrels, oocyst shedding began between 4 and 11 days post infection. While infection in mice, gerbils, ferrets and eastern gray squirrels was asymptomatic or had mild clinical signs, Eurasian red squirrels developed severe cryptosporidiosis that resulted in host death. The rapid onset of clinical signs characterized by severe diarrhea, apathy, loss of appetite and subsequent death of the individual may explain the sporadic occurrence of this Cryptosporidium in field studies and its concurrent spread in the population of native European squirrels. Oocysts obtained from a naturally infected human, the original inoculum, were 5.64 × 5.37 μm and did not differ in size from oocysts obtained from experimentally infected hosts. Cryptosporidium chipmunk genotype I infection was localized exclusively in the cecum and anterior part of the colon.

CONCLUSIONS

Based on these differences in genetics, host specificity and pathogenicity, we propose the name Cryptosporidium mortiferum n. sp. for this parasite previously known as Cryptosporidium chipmunk genotype I.

Molecular characterization of Cryptosporidium and Giardia in environmental samples and faecal samples from biogas users in Bac Giang, Vietnam

Little is known about Cryptosporidium and Giardia in biogas waste and humans in Vietnam. There is a potential risk of infections during or after using the biogas system. The detected protozoan genotypes are zoonotic pathogens, and contamination of vegetables may relay through runoff to the surface waters and soil. The objective of this study was to understand the role of the environment in the epidemiology of human infections in Bac Giang province, Vietnam, with a focus on investigating the presence of Cryptosporidium spp. genotypes and Giardia assemblages among 239 environmental samples and 94 faecal samples of biogas users. PCR and sequencing analysis were used to identify the occurrence and genotypes of Cryptosporidium and Giardia in these samples. Results showed that 13/333 (3.9 %) and 9/333 (2.7 %) samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively. Characterization revealed the presence of Cryptosporidium scrofarum, C. suis, C. meleagridis, C. bailey and Giardia intestinalis assemblage A and E. C. scrofarum and Giardia assemblage E were identified for the first time in humans in Bac Giang. The current information from the above investigations will be valuable for protozoan source tracking and control interventions against Cryptosporidium and Giardia infection associated with biogas wastes in Vietnam.

Diagnosis and control of cryptosporidiosis in farm animals

Cryptosporidium is a pathogenic protozoan parasite infecting the gastrointestinal epithelium of human and animal hosts. In farm animals, cryptosporidiosis causes significant economic losses including deaths in newborn animals, retarded growth, increased labor involved and high cost of drugs. The detection of Cryptosporidium oocysts in fecal samples is traditionally dependent on examination of stained slides by light microscope or by advanced microscopical tools such as: electron microscopy and phase contrast microscopy. Immunological diagnosis using either antibody or antigen detection could offer high sensitivity and specificity. Examples for these tests are Enzyme Linked Immunosorbent Assay (ELISA), Immunochromatographic tests, Immunochromatographic lateral flow (ICLF), Immunofluorescence assays (IFA) and Flow cytometry coupled with cell sorting. Molecular methods could differentiate species and genotypes of Cryptosporidium and help in studying the epidemiological features of this parasite with rapid, simple and sensitive procedures. Nanotechnology-based platforms could improve the sensitivity and specificity of other detection methods like: ELISA, ICLF, IFA and polymerase chain reaction. As the available prophylactic and therapeutic drugs or natural products treatments are insufficient and no approved vaccines are available, the best approach to control this parasite is by following firm hygienic measures. Many vaccine attempts were performed using hyperimmune colostrum, live or attenuated vaccines, recombinant and Deoxyribonucleic acid vaccines. Also, Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 technology could help in Cryptosporidium genome editing to improve drug and vaccine discovery. Another approach that could be useful for assigning drug targets is metabolomics. Probiotics were also used successfully in the treatment of acute diarrhea and they proved a limiting effect on cryptosporidiosis in animal models. In addition, nanotherapy-based approaches could provide a good strategy for improving the potency of any type of drugs against Cryptosporidium and give good anti-cryptosporidial effects. In conclusion, accurate diagnosis using advanced techniques is the key to the control and prevention of cryptosporidiosis.

First report of rodent-adapted Cryptosporidium wrairi in an immunocompetent child, Spain

Cryptosporidiosis is a leading cause of childhood diarrhoea. Two species, Cryptosporidium hominis and Cryptosporidium parvum, are responsible for most confirmed cases globally. Close contact with pet animals can be an unnoticed source of children infections. We describe a case of infection by rodent-adapted Cryptosporidium wrairi in a 22-month-old immunocompetent toddler with no clinical manifestations in close contact with a pet guinea pig and poor personal hygiene practices in Majadahonda (Madrid, Spain). Attempts to determine the C. wrairi genotype family at the 60-kDa glycoprotein marker failed repeatedly. This is the first description of C. wrairi in a human host. Although a spurious infection cannot be completely ruled out, data presented here suggest that C. wrairi can be transmitted zoonotically.

Small and intermediate size structural RNAs in the unicellular parasite Cryptosporidium parvum as revealed by sRNA-seq and comparative genomics

Small and intermediate-size noncoding RNAs (sRNAs and is-ncRNAs) have been shown to play important regulatory roles in the development of several eukaryotic organisms. However, they have not been thoroughly explored in Cryptosporidium parvum, an obligate zoonotic protist parasite responsible for the diarrhoeal disease cryptosporidiosis. Using Illumina sequencing of a small RNA library, a systematic identification of novel small and is-ncRNAs was performed in C. parvum excysted sporozoites. A total of 79 novel is-ncRNA candidates, including antisense, intergenic and intronic is-ncRNAs, were identified, including 7 new small nucleolar RNAs (snoRNAs). Expression of select novel is-ncRNAs was confirmed by RT-PCR. Phylogenetic conservation was analysed using covariance models (CMs) in related Cryptosporidium and apicomplexan parasite genome sequences. A potential new type of small ncRNA derived from tRNA fragments was observed. Overall, a deep profiling analysis of novel is-ncRNAs in C. parvum and related species revealed structural features and conservation of these novel is-ncRNAs. Covariance models can be used to detect is-ncRNA genes in other closely related parasites. These findings provide important new sequences for additional functional characterization of novel is-ncRNAs in the protist pathogen C. parvum.

Cryptosporidium species in non-human animal species in Latin America: Systematic review and meta-analysis

Cryptosporidiosis is an infection caused by a protozoon that inhabits the gastrointestinal tract. More than forty valid species have been described in the genus Cryptosporidium, infecting a broad range of hosts around the world, some with zoonotic transmission and others with predominant anthroponotic transmission. Prevalence studies conducted in Latin American countries have been specific, without consolidating information on species prevalences. Thus, the aim of this study was to perform a systematic review and meta-analysis addressing the prevalence of Cryptosporidium species in animals in Latin America. The estimated pooled prevalence rate for cryptosporidiosis in animals, by means of meta-analysis with a random-effects model, based on species identification, was 18.0% (95% CI 11.0%-27.0%) with high heterogeneity. The estimated overall prevalence was 20.3% (36/177) in pets, 19.9% (1309/6573) in livestock animals and 23.9% (954/3995) in exotic/captive animals. Evidence of circulation of 16 Cryptosporidium species was found in five Latin American countries: Brazil, Colombia, Chile, Argentina and Mexico. Through meta-analysis with a random-effects model, the pooled prevalence rate for Cryptosporidium parvum was 0.7% (95% CI 0.2%-2.4%). Cryptosporidium felis (8.5%) was the most prevalent species in pets, C. parvum (10.3%) in livestock animals and Cryptosporidium galli (17.6%) in exotic/captive animals. C. parvum was the species with the greatest geographical dispersion, which can be explained by its eurixenic and zoonotic potential. Few studies on cryptosporidiosis in animals in Latin America were found, which shows that there is a need for investment in and expansion of studies on this parasite. The pooled prevalence of C. parvum in Latin America and its wide circulation are similar to what has been observed in other developing regions, which reaffirms the importance of this species as the cause of a neglected, emerging and zoonotic parasitosis.

Prevalence, risk factor and diversity of Cryptosporidium in cattle in Latvia

The epidemiology of Cryptosporidium spp. in Latvia was investigated by testing fecal samples from 926 animals aged from one day to 24 years for the presence of Cryptosporidium spp. oocysts. The samples were collected from 87 cattle farms and from four slaughterhouses, and analyzed by conventional and fluorescent microscopy, followed by Cryptosporidium species and C. parvum subtype differentiation. Moreover, using a questionnaire, we surveyed factors that could be relevant as risk factors of Cryptosporidium spp. infection on the farms. Cryptosporidium spp. were shed by 33.8% of the investigated cattle and at least one shedding animal was found on 77.8% of the farms. In the present study, all four Cryptosporidium species reported to commonly infect cattle and two additional Cryptosporidium species (C. scrofarum and C. ubiquitum) were identified. In addition, mix infections of C. parvum/C. bovis, C. bovis/C. ryanae, C. parvum/C. ryanae, C. parvum/C. andersoni and C. bovis/C. andersoni were observed. C. parvum and C. bovis was mostly prevalent in young animals (0-3 months old) and in addition, diarrhea associated with C. parvum infection was observed only in very young animals. Cryptosporidium andersoni and C. ryanae in age group 0-3 months was observed in low prevalence, while a higher proportion of animals with diarrhea associated with C. andersoni infection was observed in very young animals and with C. ryanae in animals age group 4-24 months. Eight previously described C. parvum subtypes were observed. The majority of the subtypes were in the IIa subtype family, while one subtype was identified from the IId subtype family. The most common subtype was IIaA15G2R1, which was found in 34.2% of the C. parvum successfully subtyped samples. The probability of Cryptosporidium spp. associated diarrhea in cattle decreased significantly with the age of the animals and a prolonged period during which calves were fed with milk.

Long-read assembly and comparative evidence-based reanalysis of Cryptosporidium genome sequences reveal expanded transporter repertoire and duplication of entire chromosome ends including subtelomeric regions

Cryptosporidiosis is a leading cause of waterborne diarrheal disease globally and an important contributor to mortality in infants and the immunosuppressed. Despite its importance, the Cryptosporidium community has only had access to a good, but incomplete, Cryptosporidium parvum IOWA reference genome sequence. Incomplete reference sequences hamper annotation, experimental design, and interpretation. We have generated a new C. parvum IOWA genome assembly supported by Pacific Biosciences (PacBio) and Oxford Nanopore long-read technologies and a new comparative and consistent genome annotation for three closely related species: C. parvum, Cryptosporidium hominis, and Cryptosporidium tyzzeri We made 1926 C. parvum annotation updates based on experimental evidence. They include new transporters, ncRNAs, introns, and altered gene structures. The new assembly and annotation revealed a complete Dnmt2 methylase ortholog. Comparative annotation between C. parvum, C. hominis, and C. tyzzeri revealed that most "missing" orthologs are found, suggesting that the biological differences between the species must result from gene copy number variation, differences in gene regulation, and single-nucleotide variants (SNVs). Using the new assembly and annotation as reference, 190 genes are identified as evolving under positive selection, including many not detected previously. The new C. parvum IOWA reference genome assembly is larger, gap free, and lacks ambiguous bases. This chromosomal assembly recovers all 16 chromosome ends, 13 of which are contiguously assembled. The three remaining chromosome ends are provisionally placed. These ends represent duplication of entire chromosome ends including subtelomeric regions revealing a new level of genome plasticity that will both inform and impact future research.

Zoonotic Cryptosporidium spp. in Wild Rodents and Shrews

There has been a significant increase in the number of reported human cryptosporidiosis cases in recent years. The aim of this study is to estimate the prevalence of Cryptosporidium spp. in wild rodents and shrews, and investigate the species and genotype distribution to assess zoonotic risk. Partial 18S rRNA gene nested-PCR reveals that 36.8, 53.9 and 41.9% of mice, voles and shrews are infected with Cryptosporidium species. The highest prevalence occurred in the Microtus agrestis (field vole) and Myodes glareolus (bank vole). Interestingly, bank voles caught in fields were significantly more often Cryptosporidium-positive compared to those caught in forests. The proportion of infected animals increases from over-wintered (spring and summer) to juveniles (autumn) suggesting acquired immunity in older animals. Based on Sanger sequencing and phylogenetic analyses, Apodemus flavicollis (yellow-necked mouse) is commonly infected with zoonotic C. ditrichi. Voles carry multiple different Cryptosporidium sp. and genotypes, some of which are novel. C. andersoni, another zoonotic species, is identified in the Craseomys rufocanus (grey-sided vole). Shrews carry novel shrew genotypes. In conclusion, this study indicates that Cryptosporidium protozoan are present in mouse, vole and shrew populations around Finland and the highest zoonotic risk is associated with C. ditrichi in Apodemus flavicollis and C. andersoni in Craseomys rufocanus. C. parvum, the most common zoonotic species in human infections, was not detected.

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.

Historical contingency, geography and anthropogenic patterns of exposure drive the evolution of host switching in the Blastocystis species-complex

Parasites have the power to impose significant regulatory pressures on host populations, making evolutionary patterns of host switching by parasites salient to a range of contemporary ecological issues. However, relatively little is known about the colonization of new hosts by parasitic, commensal and mutualistic eukaryotes of metazoans. As ubiquitous symbionts of coelomate animals, Blastocystis spp. represent excellent candidate organisms for the study of evolutionary patterns of host switching by protists. Here, we apply a big-data phylogenetic approach using archival sequence data to assess the relative roles of several host-associated traits in shaping the evolutionary history of the Blastocystis species-complex within an ecological framework. Patterns of host usage were principally determined by geographic location and shared environments of hosts, suggesting that weight of exposure (i.e. propagule pressure) represents the primary force for colonization of new hosts within the Blastocystis species-complex. While Blastocystis lineages showed a propensity to recolonize the same host taxa, these taxa were often evolutionarily unrelated, suggesting that historical contingency and retention of previous adaptions by the parasite were more important to host switching than host phylogeny. Ultimately, our findings highlight the ability of ecological theory (i.e. ‘ecological fitting’) to explain host switching and host specificity within the Blastocystis species-complex.

Cryptosporidium Infection and Associated Risk Factors among Cattle in the Central Region of Ghana

Cryptosporidium species infects a wide number of animals including livestock all over the world. The current study was done to determine the prevalence and risk factors of Cryptosporidium infection among cattle in the Central Region of Ghana. Two hundred and eighty-seven (287) faecal samples were randomly collected from animals on eight cattle farms in four districts across two agroecological zones. A commercial enzyme-linked immunosorbent assay kit (CoproELISA, Savyon® Diagnostics Ltd., Israel) for Cryptosporidium was used in the detection of Cryptosporidium antigens in faecal samples. Characteristics of the animals such as age, sex, and location, as well as consistency of faecal samples, were collected. Pearson's chi-square or Fisher's exact test was used to determine the association between explanatory variables and Cryptosporidium infection while a logistic regression model was also used to determine the risk of infection. The overall prevalence of Cryptosporidium infection was 23.7% (95% CI, 18.7-28.6). Prevalence was significantly higher (p = 0.049) among cattle aged 12-month old and above compared to those under 12 months of age. Among the four districts in the study area, Cape Coast metropolis recorded a significantly higher prevalence (60.5%; CI, 49.3-71.8), (p < 0.001) compared to the other three. Furthermore, a significant association was observed between the consistency of faecal samples and Cryptosporidium infection (p = 0.042). The prevalence of Cryptosporidium infection was also significantly higher among cattle from the coastal savanna zone (26.9%; 95% CI, 21.0-32.8) compared to those from the semideciduous forest area (p = 0.017). Cattle in the forest zone had a lower risk of being infected with the parasite compared to those from the coastal savanna zone (OR 0.408; 95% CI, 0.182-0.915). In conclusion, Cryptosporidium was prevalent among cattle in the Central Region of Ghana. A higher prevalence of Cryptosporidium infection occurred in older animals and among animals in the coastal agroecological zone. The area of location and age of animals were identified as risk factors for Cryptosporidium infection in the Central Region of Ghana.

First Molecular Characterization of Cryptosporidium spp. in Patients Living with HIV in Honduras

Cryptosporidiosis is one of the most important causes of gastroenteritis in the world, especially in low- and middle-income countries. It is caused by the Apicomplexan parasite Cryptosporidium spp., and mainly affects children and immunocompromised people, in whom it can pose a serious threat to their health, or even be life threatening. In Honduras, there are no data on parasite species or on molecular diversity or Cryptosporidium subtypes. Therefore, a cross-sectional study was conducted between September 2019 and March 2020 for the molecular identification of Cryptosporidium spp. in 102 patients living with HIV who attended a national hospital in Tegucigalpa. Stool samples were analyzed by direct microscopy, acid-fast stained smears, and a rapid lateral flow immunochromatographic test. All samples that tested positive were molecularly analyzed to identify the species and subtype of the parasite using three different markers: gp60, cowp, and 18Sr. PCR products were also sequenced. Four out of 102 samples (3.92%) were positive for Cryptosporidiumparvum, and all were assigned to subtype IIa. These findings suggest a possible zoonotic transmission in this population.

The Age-Related Cryptosporidium Species Distribution in Asymptomatic Cattle from North-Western SPAIN

Simple Summary

An age-related distribution of Cryptosporidium species has been reported in cattle, with the pathogenic and zoonotic C. parvum being predominant in suckling calves, C. bovis and C. ryanae being predominant in post-weaned calves and C. andersoni being predominant in adults. However, variants to this pattern have recently been reported. Unravelling the age-related species distribution pattern in cattle from a particular region will allow determining those age classes posing a higher risk to public and animal health. Thus, fecal samples from asymptomatic cattle were collected in north-western Spain. Cryptosporidium detection and species identification was performed by molecular methods. Cryptosporidium prevalence was 16.7%; it significantly decreased with age. Cryptosporidium andersoni, C. bovis, C. occultus, C. parvum, C. ryanae and C. xiaoi were identified. Cryptosporidium parvum was predominant in calves younger than 1 month and C. bovis was predominant in the rest of the age groups. The presence of C. parvum in all age groups implies animal and public health concerns. The predominance of C. bovis in cattle older than 1 month supports the idea that the age-related pattern of Cryptosporidium species described in cattle is not fully consistent, and thus further studies are needed to identify those factors determining the species distribution.

Abstract

An age-related distribution of Cryptosporidium species has been reported in cattle, with C. parvum being predominant in suckling calves, C. bovis and C. ryanae being predominant in post-weaned calves and C. andersoni being predominant in adults. However, variants to this pattern have recently been reported. Thus, fecal samples (n = 594) from asymptomatic cattle were collected in north-western Spain. Animals were classified as <1 month (G1), 1–2 months (G2), 2–12 months (G3), 12–24 months (G4) and >2 years (G5). Cryptosporidium detection and species identification were performed by SSU rRNA PCR. Individual Cryptosporidium prevalence was 16.7%; it significantly decreased with age. Cryptosporidium parvum was predominant in G1 and C. bovis was predominant in the rest of the age classes; C. bovis and C. ryanae were especially prevalent in G2 and G3. Cryptosporidium occultus was not found in suckling calves. Finally, C. andersoni and C. xiaoi were occasionally detected in G5. The presence of C. parvum in all age classes implies significant animal and public health concerns. The predominance of C. bovis in cattle older than 1 month supports the idea that the age-related pattern of Cryptosporidium species described in cattle is not fully consistent, and thus further studies are still needed to identify those factors determining the species distribution.

Analysis of Long Non-Coding RNA in Cryptosporidium parvum Reveals Significant Stage-Specific Antisense Transcription

Cryptosporidium is a protist parasite that has been identified as the second leading cause of moderate to severe diarrhea in children younger than two and a significant cause of mortality worldwide. Cryptosporidium has a complex, obligate, intracellular but extra cytoplasmic lifecycle in a single host. How genes are regulated in this parasite remains largely unknown. Long non-coding RNAs (lncRNAs) play critical regulatory roles, including gene expression across a broad range of organisms. Cryptosporidium lncRNAs have been reported to enter the host cell nucleus and affect the host response. However, no systematic study of lncRNAs in Cryptosporidium has been conducted to identify additional lncRNAs. In this study, we analyzed a C. parvum in vitro strand-specific RNA-seq developmental time series covering both asexual and sexual stages to identify lncRNAs associated with parasite development. In total, we identified 396 novel lncRNAs, mostly antisense, with 86% being differentially expressed. Surprisingly, nearly 10% of annotated mRNAs have an antisense transcript. lncRNAs occur most often at the 3' end of their corresponding sense mRNA. Putative lncRNA regulatory regions were identified and many appear to encode bidirectional promoters. A positive correlation between lncRNA and upstream mRNA expression was observed. Evolutionary conservation and expression of lncRNA candidates was observed between C. parvum, C. hominis and C. baileyi. Ten C. parvum protein-encoding genes with antisense transcripts have P. falciparum orthologs that also have antisense transcripts. Three C. parvum lncRNAs with exceptional properties (e.g., intron splicing) were experimentally validated using RT-PCR and RT-qPCR. This initial characterization of the C. parvum non-coding transcriptome facilitates further investigations into the roles of lncRNAs in parasite development and host-pathogen interactions.

Comparative genomic analysis of the principal Cryptosporidium species that infect humans

Cryptosporidium parasites are ubiquitous and can infect a broad range of vertebrates and are considered the most frequent protozoa associated with waterborne parasitic outbreaks. The intestine is the target of three of the species most frequently found in humans: C. hominis, C. parvum, and. C. meleagridis. Despite the recent advance in genome sequencing projects for this apicomplexan, a broad genomic comparison including the three species most prevalent in humans have not been published so far. In this work, we downloaded raw NGS data, assembled it under normalized conditions, and compared 23 publicly available genomes of C. hominis, C. parvum, and C. meleagridis. Although few genomes showed highly fragmented assemblies, most of them had less than 500 scaffolds and mean coverage that ranged between 35X and 511X. Synonymous single nucleotide variants were the most common in C. hominis and C. meleagridis, while in C. parvum, they accounted for around 50% of the SNV observed. Furthermore, deleterious nucleotide substitutions common to all three species were more common in genes associated with DNA repair, recombination, and chromosome-associated proteins. Indel events were observed in the 23 studied isolates that spanned up to 500 bases. The highest number of deletions was observed in C. meleagridis, followed by C. hominis, with more than 60 species-specific deletions found in some isolates of these two species. Although several genes with indel events have been partially annotated, most of them remain to encode uncharacterized proteins.

Potential Risk of Three Zoonotic Protozoa (Cryptosporidium spp., Giardia duodenalis, and Toxoplasma gondii) Transmission from Fish Consumption

In recent decades, worldwide fish consumption has increased notably worldwide. Despite the health benefits of fish consumption, it also can suppose a risk because of fishborne diseases, including parasitic infections. Global changes are leading to the emergence of parasites in new locations and to the appearance of new sources of transmission. That is the case of the zoonotic protozoa Cryptosporidium spp., Giardia duodenalis, and Toxoplasma gondii; all of them reach aquatic environments and have been found in shellfish. Similarly, these protozoa can be present in other aquatic animals, such as fish. The present review gives an overview on these three zoonotic protozoa in order to understand their potential presence in fish and to comprehensively revise all the evidences of fish as a new potential source of Cryptosporidium spp., Giardia duodenalis, and Toxoplasma gondii transmission. All of them have been found in both marine and freshwater fishes. Until now, it has not been possible to demonstrate that fish are natural hosts for these protozoa; otherwise, they would merely act as mechanical transporters. Nevertheless, even if fish only accumulate and transport these protozoa, they could be a "new" source of infection for people.

Cryptosporidium spp. and Giardia duodenalis emissions from humans and animals in the Three Gorges Reservoir in Chongqing, China

Cryptosporidium spp. and Giardia duodenalis are two waterborne protozoan parasites that can cause diarrhea. Human and animal feces in surface water are a major source of these pathogens. This paper presents a GloWPa-TGR-Crypto model that estimates Cryptosporidium and G. duodenalis emissions from human and animal feces in the Three Gorges Reservoir (TGR), and uses scenario analysis to predict the effects of sanitation, urbanization, and population growth on oocyst and cyst emissions for 2050. Our model estimated annual emissions of 1.6 × 10¹⁵ oocysts and 2.1 × 10¹⁵ cysts from human and animal feces, respectively. Humans were the largest contributors of oocysts and cysts, followed by pigs and poultry. Cities were hot-spots for human emissions, while districts with high livestock populations accounted for the highest animal emissions. Our model was the most sensitive to oocyst excretion rates. The results indicated that 74% and 87% of total emissions came from urban areas and humans, respectively, and 86% of total human emissions were produced by the urban population. The scenario analysis showed a potential decrease in oocyst and cyst emissions with improvements in urbanization, sanitation, wastewater treatment, and manure management, regardless of population increase. Our model can further contribute to the understanding of environmental pathways, the risk assessment of Cryptosporidium and Giardia pollution, and effective prevention and control strategies that can reduce the outbreak of waterborne diseases in the TGR and other similar watersheds.

Cryptosporidiosis and Giardiasis in Buffaloes (Bubalus bubalis)

Cryptosporidium spp. and Giardia duodenalis infect the gastrointestinal tracts of animals and humans. Both parasite groups are distributed worldwide and cause significant economic losses in animal productivity. Infected hosts presenting with and without clinical manifestations can eliminate infective forms of these protozoa, which are particularly important to One Health. Compared to the published research on cattle, relatively few studies have examined the epidemiology of cryptosporidiosis and giardiasis in buffaloes. This short review describes the global occurrence of Cryptosporidium spp. and G. duodenalis in buffaloes, including the molecular techniques employed for the identification of species/assemblages and genotypes of these protozoa. Genetic analyses of isolates of G. duodenalis and Cryptosporidium spp. from various sources (environmental, animal, and human) have been performed to investigate their epidemiology. In buffaloes, the species Cryptosporidium parvum, Cryptosporidium ryanae, Cryptosporidium bovis, and Cryptosporidium suis-like have been characterized, as well as assemblages A and E of G. duodenalis. We demonstrate that buffaloes can be infected by species of Cryptosporidium spp. and G. duodenalis assemblages with zoonotic potential. Epidemiological studies that utilize molecular biology techniques represent an important resource for efforts to control and prevent the spread of these protozoans.

The red fox (Vulpes vulpes) as a potential natural reservoir of human cryptosporidiosis by Cryptosporidium hominis in Northwest Spain

Giardia duodenalis and Cryptosporidium spp. are ubiquitous intestinal protozoa that parasitize domestic and wild animals, as well as human beings. Due to their zoonotic potential, the objective of the present study was to determine the presence of these pathogens in the fox population (Vulpes vulpes) located in Northwest Spain. A total of 197 faecal samples from legally hunted foxes were collected in the autonomous region of Galicia. The presence of G. duodenalis and Cryptosporidium spp. was investigated by PCR-based methods amplifying the small subunit ribosomal RNA (ssu rRNA) gene of the parasites. Attempts to genotype obtained positive samples were subsequently conducted at the glutamate dehydrogenase (gdh) and β-giardin (bg) genes of G. duodenalis, and the 60 kDa glycoprotein (gp60) gene of Cryptosporidium. Giardia duodenalis and Cryptosporidium spp. were identified in 19 (9.6%) and 12 (6.1%) of the investigated samples, respectively. However, five Cryptosporidium species were detected at the ssu rRNA locus: C. hominis (33.4%, 4/12), C. canis (25.0%, 3/12), C. parvum (16.7%, 2/12), C. ubiquitum (8.3%, 1/12) and C. suis (8.3%, 1/12). An additional Cryptosporidium-positive sample was identified at the genus level only. Typing and subtyping of Giardia- and Cryptosporidium-positive samples were unsuccessful. The detection of C. hominis in wild foxes indicates the probable overlapping of sylvatic and domestic cycles of this parasite in rural settings. Besides, this finding raises the question of whether red foxes may act as natural reservoirs of C. hominis. The detection of C. parvum and C. suis is suggestive of active transmission events between farm and wild animals, opening up the possibility of transmission to human beings.

Non-invasive sampling in Itatiaia National Park, Brazil: wild mammal parasite detection

Background

Non-invasive sampling through faecal collection is one of the most cost-effective alternatives for monitoring of free-living wild mammals, as it provides information on animal taxonomy as well as the dynamics of the gastrointestinal parasites that potentially infect these animals. In this context, this study aimed to perform an epidemiological survey of gastrointestinal parasites using non-invasive faecal samples from carnivores and artiodactyls identified by stool macroscopy, guard hair morphology and DNA sequencing in Itatiaia National Park. Between 2017 and 2018, faeces from carnivores and artiodactyls were collected along trails in the park. The host species were identified through macroscopic and trichological examinations and molecular biology. To investigate the parasites, the Faust, Lutz and modified Ritchie and Sheather techniques and enzyme immunoassays to detect Cryptosporidium sp. antigens were used.

Results

A total of 244 stool samples were collected. The species identified were Chrysocyon brachyurus, Leopardus guttulus, Canis familiaris, Cerdocyon thous, Puma yagouaroundi, Leopardus pardalis, Puma concolor and Sus scrofa. There were 81.1% samples that were positive for parasites distributed mainly in the high part of the park. Helminths, especially eggs of the family Ascarididae, were more frequently detected in carnivore faeces (70.9%). Protozoa, especially Cryptosporidium sp., represented the highest frequency of infection in artiodactyl faeces (87.1%). This zoonotic protozoon was detected in eight mammalian species, including in a wild boar. High values of structural richness and Shannon and Simpson diversity indices were observed for the parasites, especially in the faeces of C. brachyurus. Significant differences in parasite diversity were observed between wild and domestic animals, such as C. brachyurus and C. familiaris, respectively, and between taxonomically distant species, such as C. brachyurus and S. scrofa. The highest values for parasite similarity were found among the species that frequented similar areas of the park, such as C. brachyurus and L. guttulus.

Conclusions

The animals and parasite infections were identified through the combination of three techniques. High frequency parasite structures were diagnosed. Zoonotic protozoa were found and mainly occurred in samples from introduced species.

Molecular identification of Cryptosporidium spp. in pet snakes in Beijing, China

Few reports of Cryptosporidium spp. in snakes in China have been published. To determine the infection rate and document the presence of Cryptosporidium in pet snakes using molecular methods, 273 fecal samples were collected from eight species of pet snakes from 13 pet households in Beijing, China, and were examined by PCR amplification of the small subunit ribosomal RNA gene. Cryptosporidium was detected from 17 of 273 (6.2%) samples, and nine out of 13 households tested positive for Cryptosporidium with a range of 3.3 to 33.3% among households showing significant difference (p < 0.01). The infection rate of Cryptosporidium for females and males was 6.5% (13/201) and 5.6% (4/72), respectively, showing no significant difference (p > 0.05). Six out of eight pet snake species tested positive for Cryptosporidium with a range of 4.2 to 9.1% among species, showing no significant difference (p > 0.05). Two Cryptosporidium species were identified: Cryptosporidium serpentis in 10 samples and Cryptosporidium varanii in seven samples. No zoonotic Cryptosporidium species occur in our study populations.

Prevalence and Genotypes of Cryptosporidium in Wildlife Populations Co-Located in a Protected Watershed in the Pacific Northwest, 2013 to 2016

Between October 2013 and May 2016, 506 scat samples were collected from 22 species of wildlife located in a protected watershed of a major municipal water supply in the Pacific Northwest, USA. Overall prevalence of Cryptosporidium in the wildlife scat was 13.8% (70/506), with 15 species of wildlife found positive for Cryptosporidium. Prevalence of Cryptosporidium varied among species of wildlife, with higher prevalences observed in cougars (50.0%), mountain beavers (40.0%), and bobcats (33.3%), but none of these species are riparian-dependent. Genotyping of Cryptosporidium by sequencing PCR amplicons from the 18S rRNA gene were successful for seven species of wildlife, including bobcat, unknown predator, black-tailed deer, deer mouse, snowshoe hare, mountain beaver, and western spotted skunk. BLAST and phylogenetic analyses indicated that multiple species and genotypes of Cryptosporidium were present, with some isolates possibly co-circulating within and between wildlife populations in this protected watershed. Evidence of oocyst exchange between infected prey and their predators was also found. During the study period, several zoonotic Cryptosporidium species and genotypes that are uncommon in humans were detected in bobcat (99.58% identical to Cryptosporidium felis), unknown predator (100% identical to Cryptosporidium canis), snowshoe hare (100% identical to Cryptosporidium sp. skunk genotype), and mountain beaver (100% identical to Cryptosporidium ubiquitum). Novel sequences were also found in mountain beaver. To our knowledge, this is the first published report of a unique genotype or species of Cryptosporidium in mountain beaver (Aplodontia rufa).

Use of Markers to Determine Cryptosporidium Genotypes for Epidemiology Tracking and Detection

Polymerase chain reaction (PCR) enables amplification of specific DNA fragments for the detection and tracking of Cryptosporidium spp. Newly obtained DNA are compared to an ever-growing database of Cryptosporidium sequences with uncertain or outdated metadata in primary public repositories (i.e., EMBL/DDBJ/GenBank). Here, we describe standard operating procedures to obtain DNA sequences from Cryptosporidium spp. marker genes. Small-subunit ribosomal RNA gene, large-subunit ribosomal RNA gene, and glycoprotein 60 are amplified using conventional PCR. Amplified and sequenced genes are compared to a reference library of up-to-date curated gene sequences to identify Cryptosporidium species and variants.

Cryptosporidium Infection: Epidemiology, Pathogenesis, and Differential Diagnosis

Cryptosporidium is a protozoan that infects a wide variety of vertebrates, including humans, causing acute gastroenteritis. The disease manifests with abdominal pain and diarrhea similar to that of choleric infection. In the immunocompromised hosts, the parasite causes prolonged infections that can also be fatal. For this reason, cryptosporidiosis is considered one of riskiest opportunistic infections for patients with acquired immunodeficiency syndrome. The best way to control the infection in these patients is setting up sensitive and specific diagnostic tests for epidemiological surveillance and morbidity reduction. Here, we summarized the general aspects of Cryptosporidium infection focusing on available diagnostic tools used for the diagnosis of cryptosporidiosis. Molecular methods currently available for its detection and progress in the development of new diagnostics for cryptosporidiosis are also discussed.

Prevalence and molecular characterization of Cryptosporidium and Giardia in pre-weaned native calves in the Republic of Korea

Cryptosporidium spp. and Giardia duodenalis are protozoan parasites that cause diarrhea in humans and animals. Molecular data on Cryptosporidium spp. and G. duodenalis in calves in the Republic of Korea (ROK) is limited; thus, we investigated the prevalence of Cryptosporidium and Giardia in pre-weaned calves, analyzed the association between these parasites and diarrhea, and identified their zoonotic potential for human infection. Fecal samples were collected from 315 pre-weaned calves aged 1-60 days from 10 different regions in the ROK and screened for Cryptosporidium spp. and G. duodenalis using PCR. Overall prevalence of Cryptosporidium spp. and G. duodenalis was 4.4% (n = 14) and 12.7% (n = 40), respectively. Co-infection was not detected. All Cryptosporidium-positive samples were identified as C. parvum after sequence analysis of a small subunit rRNA fragment and further subtyped into zoonotic IIaA15G2R1 (n = 13) and IIaA18G3R1 (n = 1) by DNA sequencing of the 60-kDa glycoprotein gene. To our knowledge, this is the first report of C. parvum IIaA15G2R1 subtype in calves in the ROK. Based on β-giardin (bg) gene, G. duodenalis-positive samples belonged to assemblages E (n = 36) and A (n = 4), with the latter belonging to subtype A1, the zoonotic genotype. Six subtypes of assemblage E were identified at the bg locus: E1 (n = 6), E2 (n = 3), E3 (n = 13), E5 (n = 1), E8 (n = 1), and E11 (n = 1). The occurrence of C. parvum and G. duodenalis was not associated with diarrhea in pre-weaned Korean native calves. The present results suggest that the prevalence of C. parvum is not related to calf age; in contrast, the prevalence of G. duodenalis was significantly higher in 41-50-day-old calves (odds ratio = 9.90, 95% confidence interval 2.37-41.34; P = 0.001) than in 1-10-day-old calves. Therefore, calves are a potential source of zoonotic transmission, which may have significant public health implications.

The Cryptosporidium parvum gp60 glycoprotein expressed in the ciliate Tetrahymena thermophila is immunoreactive with sera of calves infected with Cryptosporidium oocysts

Cryptosporidium parvum is a protozoan parasite of the phylum Apicomplexa responsible for cryptosporidiosis in calves, a disease that causes significant diarrhea and impairs gain of body weight, generating important production losses. As to now, no effective drugs or vaccines are available for the treatment or prevention of bovine cryptosporidiosis. Several reports suggest that development of a vaccine to prevent cryptosporidiosis is feasible, but relatively few vaccine candidates have been characterized and tested. The most prominent C. parvum antigen is gp60, an O-glycosylated mucin-like protein tethered to the parasite membrane by a glycosylphosphatidylinositol (GPI) anchor. Gp60 has been shown to be involved in essential mechanisms for the survival of C. parvum, such as recognition, adhesion to, and invasion of host cells. This work was aimed at expressing gp60 in Tetrahymena thermophila, a ciliated protozoon with numerous advantages for the heterologous expression of eukaryotic proteins, as a first approach for the development of a recombinant vaccine for bovine cryptosporidiosis. T. thermophila-expressed gp60 localized to the protozoon cell surface and oral apparatus, and partitioned into the Triton X-114 detergent phase. This indicates that the protein entered the reticuloendothelial system of the ciliate, and suggests it contains a GPI-anchor. Homogenates of gp60-expressing T. thermophila cells were recognized by sera from calves naturally infected with C. parvum demonstrating their immunoreactivity. In summary, the heterologous expression of gp60, a C. parvum-encoded GPI-anchored protein, has been successfully demonstrated in the ciliate T. thermophila.

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.

Intestinal Parasites and the Occurrence of Zoonotic Giardia duodenalis Genotype in Captive Gibbons at Krabokkoo Wildlife Breeding Center, Thailand

Intestinal parasitic infections can have an impact on health and growth of wildlife. The current study aims were to determine the prevalence of intestinal parasites and to molecular characterize Giardia duodenalis and Cryptosporidium spp. in captive gibbons at Krabokkoo Wildlife Breeding Center, Thailand. Fifty-five gibbons, 2 agile- (Hylobates agilis), 38 lar- (Hylobates lar) and 15 pileated gibbons (Hylobates pileatus) were included in this study. Fecal samples were collected individually at Krabokkoo Wildlife Breeding Center, Chachoengsao province, eastern Thailand, in November 2013. Intestinal parasitic infections were examined by zinc sulfate centrifugation flotation and by a commercially available immunofluorescent assay (IFA) for detection of G. duodenalis and Cryptosporidium spp.. Polymerase chain reaction targeting the Giardia glutamate dehydrogenase (gdh), beta- giardin (bg), triose phosphate isomerase (tpi) genes, and the Cryptosporidium small subunit-rRNA and heat-shock protein (hsp70) following by DNA sequencing were performed on the IFA positive samples. The overall prevalence of intestinal parasitic infection in gibbons at Krabokkoo Wildlife Breeding Center was 12.7% (95%CI: 5.3–24.5), Strongyloides spp. eggs or larvae were present in all positive samples. Co-infections with G. duodenalis were detected in 1.8% (95%CI: 0.1–9.7) of the samples. Based on the sequencing results of the three genes, the IFA Giardia positive isolate typed as the zoonotic genotype B. Since the data reveals the occurrence of zoonotic Giardia genotype, good hygiene management is suggested to prevent the transmission of this pathogen from gibbon to human, and vice versa.

Cryptosporidium genotyping and land use mapping for hazard identification and source tracking in a small mixed rural-urban watershed in Southeastern Brazil

Cryptosporidium, faecal indicator organisms and physical and chemical water quality variables were monitored in a small mixed rural–urban watershed in southeastern Brazil. Cryptosporidium was present in 43% of 117 water samples analysed by microscopy. Concentrations varied from non-detects to 14 oocysts L−1. All samples were further analysed by nested-PCR, and Cryptosporidium spp. were detected in 24% (28) of them. Sequencing at the 18S rRNA locus gave high quality sequences in eight samples, revealing the presence of Cryptosporidium parvum. Cryptosporidium was not correlated with faecal indicator organisms (total coliforms, Escherichia coli, Enterococcus and coliphages), nor with physical and chemical water quality variables (e.g. turbidity, electrical conductivity and chemical oxygen demand), but it was with farm animal density (number of animals per ha). Land use mapping reinforced the suggestions from Cryptosporidium genotyping that both animals (livestock) and humans are potential sources to environmental contamination with oocysts within the watershed.

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.

Molecular characterisation and risk factor analysis of Cryptosporidium spp. in calves from Italy

To provide up-to-date information on the occurrence of Cryptosporidium in pre-weaned calves from Sardinia (Italy), the species implicated and their zoonotic potential, 147 faecal samples from 22 cattle herds were microscopically examined for Cryptosporidium oocysts; positive isolates were molecularly characterised. A questionnaire was developed to identify risk factors for Cryptosporidium infection. Overall, the percentage of positive calves and farms was 38.8 and 68.2%, respectively. The SSU rRNA-based PCR identified two Cryptosporidium species, Cryptosporidium parvum (95.8%) and C. bovis (4.2%). Sequence analyses of the glycoprotein (gp60) gene revealed that all C. parvum isolates belonged to the subtype family IIa (IIaA15G2R1 and IIaA16G3R1), with the exception of three isolates that belonged to the subtype family IId (IIdA20G1b and IIdA20). Mixed logistic regression results indicated that calves aged 15-21 days were more likely to be Cryptosporidium-positive. The risk of being positive was also significantly higher in herds from Central Sardinia and in farms using non-slatted flooring. In addition, the application of disinfectants and milk replacers was significantly associated with higher Cryptosporidium prevalence. In contrast, the risk of being positive was significantly reduced in halofuginone-treated calves. Our results reveal that a significant percentage of suckling calves are carriers of zoonotic subtypes of C. parvum. Thus, both healthy and diarrhoeic calves younger than 1 month may represent a risk for the transmission of cryptosporidiosis in humans and animals.

Monoclonal Antibodies to Intracellular Stages of Cryptosporidium parvum Define Life Cycle Progression In Vitro

Cryptosporidium is a protozoan parasite that causes gastrointestinal disease in humans and animals. Currently, there is a limited array of antibodies available against the parasite, which hinders imaging studies and makes it difficult to visualize the parasite life cycle in different culture systems. In order to alleviate this reagent gap, we created a library of novel antibodies against the intracellular life cycle stages of Cryptosporidium. We identified antibodies that recognize specific life cycle stages in distinctive ways, enabling unambiguous description of the parasite life cycle. These MAbs will aid future investigation into Cryptosporidium biology and help illuminate growth differences between various culture platforms.

Among the obstacles hindering Cryptosporidium research is the lack of an in vitro culture system that supports complete life development and propagation. This major barrier has led to a shortage of widely available anti-Cryptosporidium antibodies and a lack of markers for staging developmental progression. Previously developed antibodies against Cryptosporidium were raised against extracellular stages or recombinant proteins, leading to antibodies with limited reactivity across the parasite life cycle. Here we sought to create antibodies that recognize novel epitopes that could be used to define intracellular development. We identified a mouse epithelial cell line that supported C. parvum growth, enabling immunization of mice with infected cells to create a bank of monoclonal antibodies (MAbs) against intracellular parasite stages while avoiding the development of host-specific antibodies. From this bank, we identified 12 antibodies with a range of reactivities across the parasite life cycle. Importantly, we identified specific MAbs that can distinguish different life cycle stages, such as trophozoites, merozoites, type I versus II meronts, and macrogamonts. These MAbs provide valuable tools for the Cryptosporidium research community and will facilitate future investigation into parasite biology.

IMPORTANCECryptosporidium is a protozoan parasite that causes gastrointestinal disease in humans and animals. Currently, there is a limited array of antibodies available against the parasite, which hinders imaging studies and makes it difficult to visualize the parasite life cycle in different culture systems. In order to alleviate this reagent gap, we created a library of novel antibodies against the intracellular life cycle stages of Cryptosporidium. We identified antibodies that recognize specific life cycle stages in distinctive ways, enabling unambiguous description of the parasite life cycle. These MAbs will aid future investigation into Cryptosporidium biology and help illuminate growth differences between various culture platforms.

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.

Occurrence and molecular characterization of Giardia duodenalis cysts and Cryptosporidium oocysts in raw water samples from the Rímac River, Peru

Giardia and Cryptosporidium are potentially pathogenic protozoa which are ubiquitous in ambient surface water. The present study included 60 samples of surface water from three sampling sites from the Rímac River, Lima and Callao, Peru, to detect the occurrence of Giardia spp. and Cryptosporidium spp. and to perform molecular characterization of specimens found. Water samples were concentrated using the membrane filtration technique, and following elution, cysts and oocysts were visualized by direct immunofluorescence assay (IFA). For molecular characterization, tpi and bg gene fragments and 18S rRNA were amplified by nested PCR for Giardia and Cryptosporidium, respectively, followed by sequencing and phylogenetic analysis. Giardia cysts were found in 93.3% of the analyzed samples, whereas Cryptosporidium oocysts were detected in 15%. The positivity of the Giardia cysts was 86.6% (n = 26) in 2014, while Cryptosporidium oocysts were not detected. In 2015, both protozoa were found in raw water samples, with all 30 samples collected positive for Giardia cysts (100.0%) and 9 positive for Cryptosporidium oocysts (30.0%). Oocysts were detected in 20.0% of water samples from sites 1 (mean 5.25 oocysts/L) and 2 (mean 52.3 oocysts/L), while at site 3, oocysts were detected in 50.0% of raw water samples (mean 193.6 oocysts/L). The presence of Giardia duodenalis assemblage A was confirmed in several samples by the phylogenetic positioning of the bg and tpi genes, and the sub-assemblage AII was predominant (8/9). Sequencing for Cryptosporidium resulted in profiles compatible with Cryptosporidium hominis, Cryptosporidium meleagridis, and Cryptosporidium baileyi. This is the first time that the presence of G. duodenalis assemblage A/sub-assemblage AII and Cryptosporidium species has been reported in surface water samples in Peru. These Cryptosporidium species and the Giardia duodenalis assemblage are associated with human disease which highlights the potential risk to public health and the need to increase environmental monitoring measures to protect this water body.

Occurrence of Cryptosporidium in the water basins of nitra region, slovakia

Cryptosporidium species C. parvum and C. hominis are a common cause of human diarrheal infections worldwide. In this study we attempted to detect these parasites in fish ponds and a water reservoirs in the Nitra region of Slovakia. We identified C. parvum genotype IIaA15G1R1 and genotype IIaA16G1R1 and C. hominis genotype IeA11G3T3 in these locations. Occurrence of the same genotype of C. hominis in two different locations indicates that this parasite is most likely present in the river that connects them. These results indicate a serious threat to public health of humans since these locations are used for fishing and for recreational activities.

Diverse single-amino-acid repeat profiles in the genus Cryptosporidium

Genome sequencing has greatly contributed to our understanding of parasitic protozoa. This is particularly the case for Cryptosporidium species (phylum Apicomplexa) which are difficult to propagate. Because of their polymorphic nature, simple sequence repeats have been used extensively as genotypic markers to differentiate between isolates, but no global analysis of amino acid repeats in Cryptosporidium genomes has been reported. Taking advantage of several newly sequenced Cryptosporidium genomes, a comparative analysis of single-amino-acid repeats (SAARs) in seven species was undertaken. This analysis revealed a striking difference between the SAAR profile of the gastric and intestinal species which infect mammals and one species which infects birds. In average, total SAAR length in gastric species is only 25% of the cumulative SAAR length in the genome of Cryptosporidium parvum, Cryptosporidium hominis and Cryptosporidium meleagridis, species infectious to humans. The SAAR profile in the avian parasite Cryptosporidium baileyi stands out due to the presence of long asparagine repeats. Cryptosporidium baileyi proteins with repeats ⩾20 residues are significantly enriched in regulatory functions. As postulated for the related apicomplexan species Plasmodium falciparum, these observations suggest that Cryptosporidium SAARs evolve in response to selective pressure. The putative selective mechanisms driving SAAR evolution in Cryptosporidium species are unknown.