Cryptosporidium ryanae n. sp. (Apicomplexa: Cryptosporidiidae) in cattle (Bos taurus)

Cryptosporidium and agriculture: A review

Cryptosporidiosis is a significant contributor to global foodborne and waterborne disease burden. It is a widespread cause of diarrheal diseases that affect humans and animals worldwide. Agricultural environments can become a source of contamination with Cryptosporidium species through faecal material derived from humans and animals. This review aims to report the main findings of scientific research on Cryptosporidium species related to various agricultural sectors, and highlights the risks of cryptosporidiosis in agricultural production, the contamination sources, the importance of animal production in transmission, and the role of farmed animals as hosts of the parasites. Agricultural contamination sources can cause water pollution in groundwater and different surface waters used for drinking, recreational purposes, and irrigation. The application of contaminated manure, faecal sludge management, and irrigation with inadequately treated water are the main concerns associated with foodborne and waterborne cryptosporidiosis related to agricultural activities. The review emphasizes the public health implications of agriculture concerning the transmission risk of Cryptosporidium parasites and the urgent need for a new concept in the agriculture sector. Furthermore, the findings of this review provide valuable information for developing appropriate measures and monitoring strategies to minimize the risk of infection.

Molecular detection and characterization of Giardia spp., Cryptosporidium spp., and Blastocystis in captive wild animals rescued from central Colombia

Cryptosporidium, Giardia, and Blastocystis are significant causes of diarrhea worldwide. However, studies on their prevalence in wild animals are limited, compared to humans and domestic animals. In this study, we collected 23 stool samples from captive wild rescued animals in Boyacá, Colombia. Using conventional PCR, we detected Cryptosporidium spp., Giardia spp., and Blastocystis in over half of the samples (69.6%). Cryptosporidium spp. (43.5%) were the most commonly found, followed by Giardia spp. (39.1%) and Blastocystis (13.0%). Co-infections involving these parasites were also observed. Subsequent genotyping revealed Cryptosporidium canis and Cryptosporidium ryanae as the predominant species. These findings contribute valuable information about the ecoepidemiology of intestinal parasites in Colombian wild animals.

A highly antigenic fragment within the zoonotic Cryptosporidium parvum Gp900 glycoprotein (Domain 3) is absent in human restricted Cryptosporidium species

We identified a fragment (Domain 3-D3) of the immunodominant sporozoite surface glycoprotein of the zoonotic parasite Cryptosporidium gp900, which is absent C. hominis and C. parvum anthroponosum. The fragment is highly antigenic and is able to effectively differentiate between zoonotic C. parvum and species/genotypes that infect preferentially humans. D3 detection provides a serological tool to determine whether the source of human cryptosporidiosis is of animal or human origin. We demonstrate this in experimentally challenged piglets, mice, rats, and alpaca. We speculate that the absence of this fragment from the C. hominis and C. parvum anthroponosum gp900 protein may play a key role in their host restriction.

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.

Medical Parasitology Taxonomy Update, June 2020-June 2022

The taxonomy of medically important parasites continues to evolve. This minireview provides an update of additions and updates in the field of human parasitology from June 2020 through June 2022. A list of previously reported nomenclatural changes that have not been broadly adapted by the medical community is also included.

Past, current, and potential treatments for cryptosporidiosis in humans and farm animals: A comprehensive review

The intracellular protozoan parasite of the genus Cryptosporidium is among the leading causes of waterborne diarrheal disease outbreaks throughout the world. The parasite is transmitted by ingestion of infective oocysts that are highly stable in the environment and resistant to almost all conventional disinfection methods and water treatments. Control of the parasite infection is exceedingly difficult due to the excretion of large numbers of oocysts in the feces of infected individuals that contaminate the environment and serve as a source of infection for susceptible hosts including humans and animals. Drug development against the parasite is challenging owing to its limited genetic tractability, absence of conventional drug targets, unique intracellular location within the host, and the paucity of robust cell culture platforms for continuous parasite propagation. Despite the high prevalence of the parasite, the only US Food and Drug Administration (FDA)-approved treatment of Cryptosporidium infections is nitazoxanide, which has shown moderate efficacy in immunocompetent patients. More importantly, no effective therapeutic drugs are available for treating severe, potentially life-threatening cryptosporidiosis in immunodeficient patients, young children, and neonatal livestock. Thus, safe, inexpensive, and efficacious drugs are urgently required to reduce the ever-increasing global cryptosporidiosis burden especially in low-resource countries. Several compounds have been tested for both in vitro and in vivo efficacy against the disease. However, to date, only a few experimental compounds have been subjected to clinical trials in natural hosts, and among those none have proven efficacious. This review provides an overview of the past and present anti-Cryptosporidium pharmacotherapy in humans and agricultural animals. Herein, we also highlight the progress made in the field over the last few years and discuss the different strategies employed for discovery and development of effective prospective treatments for cryptosporidiosis.

First report of Cryptosporidium andersoni and risk factors associated with the occurrence of Cryptosporidium spp. in pre-weaned native Korean calves with diarrhea

Cryptosporidium spp. are important enteric protozoan parasites that infect humans and other animals throughout the world. Cryptosporidium infection in cattle industry leads to substantial economic losses due to diarrhea, growth retardation, weight loss, and possibly death. Most studies have focused on C. parvum, and studies on other Cryptosporidium spp. and calf diarrhea are limited. Therefore, this study aimed to investigate the occurrence of Cryptosporidium spp. in pre-weaned calves, to determine the risk factors for Cryptosporidium spp. infection such as age and season, and to identify subtypes of C. parvum circulating in the Republic of Korea (ROK). A total of 510 fecal samples were collected from calves with diarrhea and divided by age and season. Cryptosporidium spp. were first screened using PCR targeting the small subunit (SSU) rRNA gene and further the 60-kDa glycoprotein gene for subtyping of C. parvum. Out of 510 fecal samples, 71 (13.9%) were positive for Cryptosporidium spp. in pre-weaned calves with diarrhea. C. andersoni (2.8%), C. bovis (30.9%), C. parvum (29.6%), and C. ryanae (36.6%) were identified. C. ryanae was the most predominant in calves in the ROK. Calf age was a significant risk factor for C. bovis (χ² = 13.83, P = 0.001), C. parvum (χ² = 7.57, P = 0.023), and C. ryanae (χ² = 20.18, P = 0.000) occurrence. Additionally, C. parvum was detected 3.1-fold more frequently in pre-weaned calves with diarrhea in fall (95% CI: 1.23-7.81; P = 0.016) than in spring, whereas C. ryanae was 8.9-fold more frequently detected in summer (95% CI: 1.65-48.68; P = 0.011) than in spring. Three subtypes (IIaA17G4R1, IIaA18G3R1, and IIaA20G3R1) of C. parvum were identified. Of them, IIaA17G4R1 was the most common, whereas IIaA20G3R1 was not previously detected in calves in the ROK. To our knowledge, this is the first report of C. andersoni in pre-weaned calves in the ROK. The occurrence of Cryptosporidium spp. appears to be age-dependent in calves. Season had a significant effect on the occurrence of C. parvum and C. ryanae. Taken together, C. bovis and C. ryanae along with C. parvum are detected in pre-weaned calves with diarrhea and these two pathogens should not be overlooked in the diagnosis of calf diarrhea.

Performance of diagnostic assays used to detect Cryptosporidium oocysts in faecal samples of cattle in Kuwait and genotyping of Cryptosporidium species

Backgroud

Cryptosporidium species are zoonotic protozoan parasites responsible for gastroenteritis in various animals and humans. The diagnosis of Cryptosporidium presents many challenges. This research attempted to match the diagnostic efficiency of the modified Ziehl–Neelsen technique (mZN), immunochromatographic assays (IC), and enzyme-linked immunosorbent assay (ELISA) for the detection of Cryptosporidium in faecal samples of cattle in Kuwait. In addition, polymerase chain reaction (PCR) was utilised to determine the predominant species infecting cattle in Kuwait and correlating the detected species with the results of different diagnostic tests used, the presence or absence of clinical signs, and the age group of the infected cattle.

Results

Of 400 analysed faecal samples, Cryptosporidium positive samples were 23%, 15.25%, and 14% using IC, ELISA, and mZN. IC had the highest sensitivity (74.07%), and mZN had the highest specificity (98.29%) using a composite reference standard (CRS) as a gold standard. The rapid IC test results in high false-positive results of cryptosporidiosis, whereas using mZN alone is insufficient to declare a negative faecal sample. Only 74.5% (35/47) of Cryptosporidium-positive samples by the three assays could be amplified by PCR. This study was the first to genotype Cryptosporidium in Kuwait. Cryptosporidium parvum (n = 26) was the dominant species detected from cattle samples, followed by C. andersoni (n = 6), C. bovis (n = 2), and C. raynae (n = 1). The findings showed a statistically relevant relationship between diarrhoea and the detection of Cryptosporidium spp. in faecal samples of cattle (p-value = 0.0003). Pre-weaned calves were the most vulnerable age group to Cryptosporidium spp. infection (p-value = 0.0007).

Conclusion

For screening of Cryptosporidium infection in faecal samples, antigen detection or PCR methods combined with one of the microscopy techniques should be used. Cryptosporidium parvum was the prepoderant Cryptosporidium spp. recovered from cattle samples in Kuwait followed by C. andersoni. Cryptosporidium parvum is a significant risk factor for diarrhoea in pre-weaned calves. However, further study is needed as many other causes of diarrhoea in calves must be ruled out before a diagnosis of Cryptosporidium diarrhoea can be made.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03435-w.

Overview on Cryptosporidium bovis and Its Effect on Calves in Some Governorates in Egypt

The present study was conducted to elucidate the prevalence of Cryptosporidium bovis in suckling and weaned cattle calves (Bubalus bubalis) from different governorates in northern, middle, and southern Egypt, such as Behera, Menofia, Qaliubiya, Assiut, and Sohag; result revealed that from the overall examined fecal samples (n = 825), the overall prevalence was 7.27%, the highest significant infection rate was in young suckling calves less than one month (8.2%), and seasonally, winter season has the highest significant level (11.24%), but sex and locality were of no significant effect on the prevalence of infection in this study. Gene sequencing and phylogenetic analysis of the 18SSU-rRNA gene of the local bovine isolate were performed, and it was found that C. bovis genotype was highly similar to human isolate, which provoke the zoonotic transmission of bovine isolate to humans and identified as a potential source for human cryptosporidiosis infection in Egypt.

Cryptosporidium: Still Open Scenarios

Cryptosporidiosis is increasingly identified as a leading cause of childhood diarrhea and malnutrition in both low-income and high-income countries. The strong impact on public health in epidemic scenarios makes it increasingly essential to identify the sources of infection and understand the transmission routes in order to apply the right prevention or treatment protocols. The objective of this literature review was to present an overview of the current state of human cryptosporidiosis, reviewing risk factors, discussing advances in the drug treatment and epidemiology, and emphasizing the need to identify a government system for reporting diagnosed cases, hitherto undervalued.

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.

Cross-Border Investigations on the Prevalence and Transmission Dynamics of Cryptosporidium Species in Dairy Cattle Farms in Western Mainland Europe

Cryptosporidium is an apicomplexan parasitic protist, which infects a wide range of hosts, causing cryptosporidiosis disease. In farms, the incidence of this disease is high in animals such as cows, leading to extensive economic loss in the livestock industry. Infected cows may also act as a major reservoir of Cryptosporidium spp., in particular C. parvum, the most common cause of cryptosporidiosis in these animals. This poses a risk to the trading of livestock, to other farms via breeding centres, and to human health. This study is a part of a global project aimed at strategies to tackle cryptosporidiosis. To reach this target, it was essential to determine whether prevalence was dependent on the studied countries or if the issue was borderless. Indeed, C. parvum occurrence was assessed across dairy farms in certain regions of Belgium, France, and the Netherlands. At the same time, the animal-to-animal transmission of the circulating C. parvum subtypes was studied. To accomplish this, we analysed 1084 faecal samples, corresponding to 57 dairy farms from all three countries. To this end, 18S rRNA and gp60 genes fragments were amplified, followed by DNA sequencing, which was subsequently used for detection and subtyping C. parvum. Bioinformatic and phylogenetic methods were integrated to analyse and characterise the obtained DNA sequences. Our results show 25.7%, 24.9% and 20.8% prevalence of Cryptosporidium spp. in Belgium, France, and the Netherlands respectively. Overall, 93% of the farms were Cryptosporidium positive. The gp60 subtyping demonstrated a significant number of the C. parvum positives belonged to the IIa allelic family, which has been also identified in humans. Therefore, this study highlights how prevalent C. parvum is in dairy farms and further suggests cattle as a possible carrier of zoonotic C. parvum subtypes, which could pose a threat to human health.

Prevalence and distribution pattern of Cryptosporidium spp. among pre-weaned diarrheic calves in the Republic of Korea

Cryptosporidium spp. are protozoan parasites that belong to subphylum apicomplexa and cause diarrhea in humans and animals worldwide. Data on the prevalence of Cryptosporidium spp. and its subtypes among calves in the Republic of Korea (KOR) are sparse. Hence, our study aimed to investigate the prevalence and association between the age of calf and the identified Cryptosporidium spp. and to determine the genotypes/subtypes of Cryptosporidium spp. in pre-weaned calves with diarrhea in the KOR. A total of 460 diarrheic fecal samples were collected from calves aged 1−60 days and screened for Cryptosporidium spp. by the 18S rRNA gene. Species identification was determined using the sequencing analysis of the 18S rRNA gene, and C. parvum-positive samples were subtyped via the sequence analysis of the 60-kDa glycoprotein (gp60) gene. Sequence analysis based on the 18S rRNA gene revealed the presence of three Cryptosporidium spp., namely, C. parvum (n = 72), C. ryanae (n = 12), and C. bovis (n = 2). Co-infection by these species was not observed. The infection rate was the highest in calves aged 11−20 days (26.1%, 95% CI 17.1−35.1), whereas the lowest rate was observed in calves aged 21−30 days (7.7%, 95% CI 0.0−16.1). The prevalence of C. parvum was detected exclusively in calves aged ≤20 days, and the highest infection rate of C. ryanae was seen in calves ≥31 days of age. The occurrence of C. parvum (χ² = 25.300, P = 0.000) and C. ryanae (χ² = 18.020, P = 0.001) was significantly associated with the age of the calves. Eleven different subtypes of the IIa family that belonging to C. parvum were recognized via the sequence analyses of the gp60 gene. Except for two (IIaA18G3R1 and IIaA15G2R1) subtypes, nine subtypes were first identified in calves with diarrhea in the KOR. IIaA18G3R1 was the most frequently detected subtype (72.2% of calves), followed by IIaA17G3R1 (5.6%), IIaA15G2R1 (4.2%), IIaA19G4R1 (4.2%), IIaA16G4R1 (2.8%), IIaA17G4R1 (2.8%), IIaA19G3R (2.8%), IIaA14G1R1 (1.4%), IIaA14G3R1 (1.4%), IIaA15G1R1 (1.4%), and IIaA19G1R1 (1.4%) These results suggest that the prevalence of Cryptosporidium spp. is significantly associated with calf age. Furthermore, the findings demonstrate the high genetic diversity of C. parvum and the widespread occurrence of zoonotic C. parvum in pre-weaned calves. Hence, calves are a potential source of zoonotic transmission with considerable public health implications.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

Taxonomy and molecular epidemiology of Cryptosporidium and Giardia - a 50 year perspective (1971-2021)

The protozoan parasites Cryptosporidium and Giardia are significant causes of diarrhoea worldwide and are responsible for numerous waterborne and foodborne outbreaks of diseases. Over the last 50 years, the development of improved detection and typing tools has facilitated the expanding range of named species. Currently at least 44 Cryptosporidium spp. and >120 genotypes, and nine Giardia spp., are recognised. Many of these Cryptosporidium genotypes will likely be described as species in the future. The phylogenetic placement of Cryptosporidium at the genus level is still unclear and further research is required to better understand its evolutionary origins. Zoonotic transmission has long been known to play an important role in the epidemiology of cryptosporidiosis and giardiasis, and the development and application of next generation sequencing tools is providing evidence for this. Comparative whole genome sequencing is also providing key information on the genetic mechanisms for host specificity and human infectivity, and will enable One Health management of these zoonotic parasites in the future.

Cryptosporidium parvum infection and management-based risk factors of dairy calves in Taiwan

Cryptosporidiosis is one of the major causes of diarrhea in calves. Cryptosporidium parvum is considered the most important calf diarrhea pathogen in the Cryptosporidium species. Not only could infected calves spread C. parvum, but infected adult cattle could also shed oocysts. The objectives of this study were (1) to investigate the prevalence of C. parvum in dairy herds in Taiwan, including calves, the dams in delivery enclosure, the floor, and the drinking water; (2) to clarify the relationship of diarrhea, management, and C. parvum infection. Twenty dairy herds in Taiwan were selected by random sampling, including 226 calves and 198 dams, and other environmental samples were collected. A questionnaire was filled out by the farm owners to collect information regarding the management of calves and the delivery enclosure. Hierarchical logistic regression was used to analyze the risk factors for C. parvum infection. The prevalence of C. parvum infection in calves was 26.5% (60/226), while in dams, it was 19.7% (39/198). The C. parvum infection in calves increased with environmental contamination of C. parvum and clinical signs of diarrhea, while it decreased with a yard provided in the delivery enclosure. In conclusion, the management of the delivery enclosure appears to be more important for preventing cryptosporidiosis in calves in Taiwan.

FIRST REPORT OF GENUS Cryptosporidium IN CERVIDS SPECIES: Mazama americana, Mazama nana AND Blastocerus dichotomus

We analyzed Cryptosporidium spp. in fecal samples of wild cervids (Ozotoceros bezoarticus, Blastocerus dichotomus, Mazama nana, Mazama americana, and Mazama bororo) from many Brazilian regions, a fact unprecedented in the literature. Sniffer dogs were used to collect 936 fecal samples of cervids from 14 Brazilian localities. Cervids species were identified using polymerase chain reaction (PCR) performed from genomic DNA extracted from 563 fecal samples of Ozotoceros bezoarticus, Blastocerus dichotomus, Mazama nana, Mazama americana, and Mazama bororo. Cryptosporidium spp. oocyst screening was performed using malachite green negative staining. Nested PCR (nPCR) protocols targeting the 18S rRNA and GP60 genes followed by genetic sequencing were performed for Cryptosporidium spp. detection and Cryptosporidium parvum subtyping, respectively. Nested PCR targeting actin gene and genetic sequencing were performed in samples with non-identified Cryptosporidium species by 18S rRNA amplicon sequencing. The association between the occurrence of Cryptosporidium and the presence of bovines in the same locality was evaluated using Fisher's exact test. The positivity rates of diagnostic methods were compared by McNemar test and the Kappa correlation coefficient. The prevalence rates of Cryptosporidium spp. in cervids were 1.42% (8/563) and 0.36% (2/563) by nPCR and malachite green negative staining, respectively. C. parvum IIaA16G3R1 isolate was identified in three fecal samples from M. americana, two from M. nana and one from B. dichotomus. Cryptosporidium ryanae were found in one sample from B. dichotomus. We identified a new Cryptosporidium genotype, named Cryptosporidium deer genotype BR, from one M. americana fecal sample.

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 myocastoris n. sp. (Apicomplexa: Cryptosporidiidae), the Species Adapted to the Nutria (Myocastor coypus)

Cryptosporidium spp., common parasites of vertebrates, remain poorly studied in wildlife. This study describes the novel Cryptosporidium species adapted to nutrias (Myocastor coypus). A total of 150 faecal samples of feral nutria were collected from locations in the Czech Republic and Slovakia and examined for Cryptosporidium spp. oocysts and specific DNA at the SSU, actin, HSP70, and gp60 loci. Molecular analyses revealed the presence of C. parvum (n = 1), C. ubiquitum subtype family XIId (n = 5) and Cryptosporidium myocastoris n. sp. XXIIa (n = 2), and XXIIb (n = 3). Only nutrias positive for C. myocastoris shed microscopically detectable oocysts, which measured 4.8–5.2 × 4.7–5.0 µm, and oocysts were infectious for experimentally infected nutrias with a prepatent period of 5–6 days, although not for mice, gerbils, or chickens. The infection was localised in jejunum and ileum without observable macroscopic changes. The microvilli adjacent to attached stages responded by elongating. Clinical signs were not observed in naturally or experimentally infected nutrias. Phylogenetic analyses at SSU, actin, and HSP70 loci demonstrated that C. myocastoris n. sp. is distinct from other valid Cryptosporidium species.

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.

Comparative analyses and structural insights of new class glutathione transferases in Cryptosporidium species

Cryptosporidiosis, caused by protozoan parasites of the genus Cryptosporidium, is estimated to rank as a leading cause in the global burden of neglected zoonotic parasitic diseases. This diarrheal disease is the second leading cause of death in children under 5 years of age. Based on the C. parvum transcriptome data, glutathione transferase (GST) has been suggested as a drug target against this pathogen. GSTs are diverse multifunctional proteins involved in cellular defense and detoxification in organisms and help pathogens to alleviate chemical and environmental stress. In this study, we performed genome-wide data mining, identification, classification and in silico structural analysis of GSTs in fifteen Cryptosporidium species. The study revealed the presence three GSTs in each of the Cryptosporidium species analyzed in the study. Based on the percentage identity and comprehensive comparative phylogenetic analysis, we assigned Cryptosporidium species GSTs to three new GST classes, named Vega (ϑ), Gamma (γ) and Psi (ψ). The study also revealed an atypical thioredoxin-like fold in the C. parvum GST1 of the Vega class, whereas C. parvum GST2 of the Gamma class and C. melagridis GST3 of the Psi class has a typical thioredoxin-like fold in the N-terminal region. This study reports the first comparative analysis of GSTs in Cryptosporidium species.

Subtyping Cryptosporidium ryanae: A Common Pathogen in Bovine Animals

Cryptosporidium ryanae is one of the most common species for cryptosporidiosis in cattle. However, little is known of the genetic characteristics of C. ryanae due to the lack of subtyping tools. In the present study, the 60-kDa glycoprotein (gp60) gene of C. ryanae was identified in whole genome sequence data and analyzed for sequence characteristics using bioinformatics tools. The protein it encodes had some of the typical characteristics of GP60 proteins, with a signal peptide, a furin cleavage site, and a glycosylphosphatidylinositol anchor at the C terminus of the protein, and numerous O-glycosylation sites. The gene sequence was used in the development of a subtyping tool, which was used in characterizing C. ryanae from 110 specimens from dairy cattle, 2 from beef cattle, 6 from yaks, and 4 from water buffaloes in China. Altogether, 17 subtypes from 8 subtype families were recognized, namely XXIa to XXIh. Possible host adaption was identified within this species, reflected by the unique occurrence of XXIa, XXIc, and XXIh in dairy cattle, yaks, and water buffaloes, respectively. Some geographical differences were detected in the distribution of subtype families in dairy cattle; specimens from southern China showed higher genetic diversity than from northern China, and the XXIa subtype family was only seen in dairy cattle in southern and eastern China. The gp60-based subtyping tool should be useful in molecular epidemiological studies of the transmission of C. ryanae.

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).

Cryptosporidium species and cryptosporidiosis in Japan: a literature review and insights into the role played by animals in its transmission

Cryptosporidium species infect domestic animals, livestock, and humans. These protozoan parasites are frequently reported as major environmental contaminants in many countries despite their differing climatic, socioeconomic, and demographic factors. This review focuses on the research findings that relate to Cryptosporidium epidemiology, genetic diversity, and associated risk factors relating to animals, contaminated water sources, and humans in Japan. Adequate knowledge of these factors is essential for understanding the economic and public health importance of cryptosporidiosis in Japan so that effective control strategies against it are implemented. Cryptosporidium infections are highly prevalent in animals in Japan. Among the different animal species, cattle infections stand out because of their economic importance and zoonotic potential. Living circumstances in Japan restrain Cryptosporidium transmission between humans, but there is evidence to suggest that animals, especially those in close contact with humans, can be potential sources of human infections. Water sampling studies have provided clues about how environmental contamination with Cryptosporidium oocysts can cause infections in livestock and wild animals. There is some evidence of person-to-person transmission of cryptosporidiosis, but only occasionally and under certain circumstances. By identifying the major role played by animals in Cryptosporidium transmission to people in Japan, we highlight the urgent need for disease control against this pathogen.

Cryptosporidium and Giardia in Ruminants

Cryptosporidium and Giardia are ubiquitous protozoan parasites that infect a broad range of vertebrate hosts, including domestic and wild animals as well as humans. Both parasites are of medical and veterinary importance. Infections with Cryptosporidium and Giardia in ruminants are associated with diarrhea outbreaks, mainly in young animals. Ruminants are potential sources of infection for humans because some species of Cryptosporidium and assemblages of Giardia duodenalis have been isolated from both ruminants and humans. Knowledge of these parasites has greatly expanded in the last 2 decades from simple microscopic observations of organisms to the knowledge acquired from molecular tools.

A single-cohort study of Cryptosporidium bovis and Cryptosporidium ryanae in dairy cattle from birth to calving

In order to investigate the infection dynamics of Cryptosporidium bovis and C. ryanae, a two-year prospective cohort study was performed on a dairy farm known to be free of C. parvum. Sixteen calves were recruited when newborn. Faecal samples were collected weekly until calves were nine weeks old, then monthly until calving or culling. Samples (n = 455) were examined by fluorescence microscopy, and when positive the species were determined by DNA sequencing. In calves up to nine weeks, C. bovis was found in 58.5% of the samples, C. ryanae in 9.2%, and both C. bovis and C. ryanae in 3.1%. The prevalence of shedding calves peaked at 87.5% in week five, which is earlier than many international studies have shown for C. bovis. The cumulative incidence of C. bovis reached 100% when the calves were five weeks old. In four calves, the species detected changed from C. bovis to C. ryanae or the other way around, and two samples were a combination of both species. Several individuals shed oocysts sporadically up to 16 months of age. The highest oocysts per gram faeces count was seen in week three (3.6 × 10⁶ OPG). Diarrhoea was not associated with oocyst shedding.

Genetic characterization reveals evidence for an association between water contamination and zoonotic transmission of a Cryptosporidium sp. from dairy cattle in West Bengal, India

Cryptosporidium sp. is an enteric parasite with zoonotic potential, and can infect a wide range of vertebrates, including human. Determining the source of infection and the mode of transmission in a new endemic region is crucial for the control of cryptosporidiosis. In the present study, we have assessed the importance of dairy cattle as a potential source of Cryptosporidium infection for humans in a newly recognized endemic region. Cryptosporidium isolates from dairy calves, humans (farm workers) and nearby water bodies were genetically characterized based on 18SrRNA and hsp70 genes. A high incidence of Cryptosporidium infection was identified in our study region. This finding is of public health concern. Cryptosporidium ryanae rather than Cryptosporidium parvum has been identified as the most prevalent infecting species in the study region. Infections were associated with clinical symptoms of infected animals. An incomplete linkage disequilibrium (LD) value with potential recombination events at 18SrRNA locus were identified for the first time in C. ryanae, which was previously reported as a clonal population. Phylogenetic analysis revealed the presence of identical genotypes of a Cryptosporidium sp. from dairy calves, farm workers and nearby water bodies and indicates an association between water contamination and zoonotic transmission of Cryptosporidiosis in our study region.

Shedding of Cryptosporidium in calves and dams: evidence of re-infection and shedding of different gp60 subtypes

One of the most common causes of calf diarrhoea is the parasite Cryptosporidium parvum. Two longitudinal studies were carried out on a dairy farm Scotland to determine the prevalence of Cryptosporidium species and subtypes in a group of calves and to determine whether dams were a possible source of calfhood infection. Fecal samples were collected from 25 calves from birth to 12 months in the first year. In the second year, fecal samples were collected from pregnant cows (n = 29) and their calves (n = 30) from birth to 6 months. The samples were tested for Cryptosporidium and speciated. Cryptosporidium parvum-positive samples were subtyped by GP60 fragment analysis. All calves in both studies shed Cryptosporidium during the study period. Cryptosporidium parvum was the predominant species detected in calves ⩽6 weeks of age and at 6 months of age, C. bovis and C. ryanae were detected in calves older than 4 weeks of age but ⩽6 months of age. The prevalence of Cryptosporidium was higher in younger animals than in older animals. GP60 subtyping revealed two subtypes in calves on this farm (IIaA15G2R1 and IIaA19G2R1) that differed in frequency by age. Adult cattle also shed C. parvum, of four gp60 genotypes.

Infection dynamics of Cryptosporidium bovis and Cryptosporidium ryanae in a Swedish dairy herd

In order to investigate the infection dynamics of Cryptosporidium bovis and Cryptosporidium ryanae, a Swedish dairy farm known to be free of C. parvum was recruited for a one-year study. Fecal samples were collected every four weeks (a total of 13 occasions) from 20 randomly selected calves younger than 65 days. A total of 238 feces samples were collected directly from the rectum and then examined with immunofluorescence microscopy; those positive for Cryptosporidium spp. oocysts were further processed by molecular species determination. Oocysts were found in 92 samples, and in 72 of these the species was successfully determined: 87.5% C. bovis, 9.7% C. ryanae and 2.8% a mix of both species. No C. parvum was found. The prevalence of shedding calves was highest at ages 4 and 5 weeks; however, the feces with the highest oocyst per gram (OPG) were registered at 2-4 weeks of age. This is earlier than what has been found in most other studies, indicating that the infection dynamics of C. bovis/C. ryanae may be affected by the presence of C. parvum. The OPG for the positive calves ranged from 200 to 1.1 × 10⁶ (geometric mean 6.88 × 10³). The youngest calf in which C. bovis was identified was 5 days old, and the youngest calf in which C. ryanae was identified was 15 days old. Calves' housing type and seasonality were not associated with differences in the shedding of oocysts. Furthermore, there was no association between the presence of diarrhea and oocyst shedding.

Extended persistence of general and cattle-associated fecal indicators in marine and freshwater environment

Fecal contamination of recreational waters with cattle manure can pose a risk to public health due to the potential presence of various zoonotic pathogens. Fecal indicator bacteria (FIB) have a long history of use in the assessment of recreational water quality, but FIB quantification provides no information about pollution sources. Microbial source tracking (MST) markers have been developed in response to a need to identify pollution sources, yet factors that influence their decay in ambient waters are often poorly understood. We investigated the influence of water type (freshwater versus marine) and select environmental parameters (indigenous microbiota, ambient sunlight) on the decay of FIB and MST markers originating from cattle manure. Experiments were conducted in situ using a submersible aquatic mesocosm containing dialysis bags filled with a mixture of cattle manure and ambient water. Culturable FIB (E. coli, enterococci) were enumerated by membrane filtration and general fecal indicator bacteria (GenBac3, Entero1a, EC23S857) and MST markers (Rum2Bac, CowM2, CowM3) were estimated by qPCR. Water type was the most significant factor influencing decay (three-way ANOVA, p: 0.006 to <0.001), although the magnitude of the effect differed among microbial targets and over time. The presence of indigenous microbiota and exposure to sunlight were significantly correlated (three-way ANOVA, p: 0.044 to <0.001) with decay of enterococci and CowM2, while E. coli, EC23S857, Rum2Bac, and CowM3 (three-way ANOVA, p: 0.044 < 0.001) were significantly impacted by sunlight or indigenous microbiota. Results indicate extended persistence of both cultivated FIB and genetic markers in marine and freshwater water types. Findings suggest that multiple environmental stressors are important determinants of FIB and MST marker persistence, but their magnitude can vary across indicators. Selective exclusion of natural aquatic microbiota and/or sunlight typically resulted in extended survival, but the effect was minor and limited to select microbial targets.

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.

Cryptosporidium occurrence in ruminants from the North Pioneer mesoregion of Paraná, Brazil

The aim of this study was to investigate the occurrence of Cryptosporidium in cattle and sheep from the North Pioneer mesoregion of the state of Paraná. For this, 317 stool samples were collected from cattle and sheep on 16 properties in six municipalities in the North Pioneer mesoregion of Paraná. For detection of Cryptosporidium species, molecular analysis was performed using nested-PCR techniques targeting the 18S rRNA gene. Of the 37 beef cows and 115 calves analyzed, four (10.8%) and 14 (12.2%), respectively, were positive for Cryptosporidium. Of the 12 cows and 52 calves, one (8.3%) and 14 (26.9%), respectively, were positive for Cryptosporidium; and of the 42 ewes and 59 lambs, six (14.3%) and 12 (20.3%), respectively were positive for Cryptosporidium. Cattle (15.3%) and sheep (17.8%) were both susceptible to infection. All the properties of the municipalities of Assaí, Ibaiti and, Leópolis presented infected animals. The study showed that Cryptosporidium occurs in most municipalities assessed, that dairy calves had a higher risk (Odds Ratio=2,66, p-value=0,018) for infection than beef calves, and that sheep are just as susceptible to infection as are cattle, and that further Cryptosporidium studies are developed.

W A A V P guideline for evaluating the efficacy of anticoccidials in mammals (pigs, dogs, cattle, sheep)

This guideline is intended as an aid in the design, implementation and interpretation of studies for the assessment of drug efficacy against Eimeria in cattle and sheep, Cystoisospora in pigs and dogs, and Cryptosporidium in cattle. It deals with the most important aspects of how to conduct both experimental and field studies for dose determination, dose confirmation and assessment of field effectiveness. Also, guidance on the selection of animals, diagnostic techniques, statistical evaluation and methods for the preparation, maintenance and use of parasites is provided. The specific management conditions that may influence the course of natural infections and consequently determine treatment schemes are mentioned and suggestions for best practice in sampling and evaluation of data prior to conducting of efficacy studies are given. The guideline is also intended to assist investigators in carrying out specific studies, provide relevant information for registration authorities involved in the decision-making process, assist in the approval of anticoccidial drugs in the target species, and facilitate the world-wide adoption of standard procedures. Although currently not implemented, issues of drug resistance testing and alternative methods for drug testing are also discussed as future issues in drug testing against mammalian coccidia.

Molecular investigation of Cryptosporidium and Giardia in pre- and post-weaned calves in Hubei Province, China

Background

The protistan pathogens Cryptosporidium and Giardia can cause significant intestinal diseases in animals and humans. Cattle, particularly calves, carrying these protists can be significant reservoirs for human infections and disease. However, little is known about the genetic make-up of Cryptosporidium and Giardia populations in cattle and other ruminants in some regions of China.

Results

In the present study, PCR-based tools were used to genetically characterise these protists in faecal samples from a total of 339 pre- and post-weaned calves from four distinct locations in Hubei Province using markers in the large (LSU) or small (SSU) subunits of nuclear ribosomal RNA genes. Cryptosporidium andersoni, C. bovis, C. ryanae and Giardia duodenalis assemblage E were detected in 0.6%, 10.9%, 4.1% and 22.6% of calves, respectively.

Conclusions

This study is the first to report the prevalence of Cryptosporidium and Giardia in pre- and post-weaned calves in Hubei Province, and encourages large-scale molecular studies of animals and humans, in an effort to better understand the epidemiology of these enteric pathogens in China.

Electronic supplementary material

The online version of this article (10.1186/s13071-017-2463-3) contains supplementary material, which is available to authorized users.

Bovine cryptosporidiosis: impact, host-parasite interaction and control strategies

Gastrointestinal disease caused by the apicomplexan parasite Cryptosporidium parvum is one of the most important diseases of young ruminant livestock, particularly neonatal calves. Infected animals may suffer from profuse watery diarrhoea, dehydration and in severe cases death can occur. At present, effective therapeutic and preventative measures are not available and a better understanding of the host-pathogen interactions is required. Cryptosporidium parvum is also an important zoonotic pathogen causing severe disease in people, with young children being particularly vulnerable. Our knowledge of the immune responses induced by Cryptosporidium parasites in clinically relevant hosts is very limited. This review discusses the impact of bovine cryptosporidiosis and describes how a thorough understanding of the host-pathogen interactions may help to identify novel prevention and control strategies.

Prevalence and risk factors for cryptosporidiosis: a global, emerging, neglected zoonosis

Background

Cryptosporidiosis is a zoonotic disease caused by the important parasitic diarrheal agent Cryptosporidium spp. Cryptosporidiosis occurs in all classes of animals and man with a rapidly expanding host range and increased importance since the occurrence of human immunodeficiency virus/acquired immunodeficiency syndrome in man.

Objectives

To review the global picture of cryptosporidiosis in man and animals with emphasis on prevalence and risk factors.

Methods

Current relevant literature on cryptosporidiosis was reviewed.

Results

Cryptosporidiosis is widely distributed and the risk factors vary from one region to another with hygiene and immune status as important risk factors.

Conclusions

Cryptosporidium spp. associated mortality has not only been reported in immune-compromised patients, but also in immune-competent patients. Yet in many countries not much attention is paid to the control and prevention of this infection in animals and man. The neglect of this disease despite the serious threat it poses to animals, their husbandry, and humans, has led the World Health Organization to list it among globally neglected diseases. To control and prevent this infection more effort needs to be directed at controlling the risk factors of the infection in man and animals.

Cryptosporidium testudinis sp. n., Cryptosporidium ducismarci Traversa, 2010 and Cryptosporidium tortoise genotype III (Apicomplexa: Cryptosporidiidae) in tortoises

Understanding of the diversity of species of Cryptosporidium Tyzzer, 1910 in tortoises remains incomplete due to the limited number of studies on these hosts. The aim of the present study was to characterise the genetic diversity and biology of cryptosporidia in tortoises of the family Testudinidae Batsch. Faecal samples were individually collected immediately after defecation and were screened for presence of cryptosporidia by microscopy using aniline-carbol-methyl violet staining, and by PCR amplification and sequence analysis targeting the small subunit rRNA (SSU), Cryptosporidium oocyst wall protein (COWP) and actin genes. Out of 387 faecal samples from 16 tortoise species belonging to 11 genera, 10 and 46 were positive for cryptosporidia by microscopy and PCR, respectively. All samples positive by microscopy were also PCR positive. Sequence analysis of amplified genes revealed the presence of the Cryptosporidium tortoise genotype I (n = 22), C. ducismarci Traversa, 2010 (n = 23) and tortoise genotype III (n = 1). Phylogenetic analyses of SSU, COWP and actin gene sequences revealed that Cryptosporidium tortoise genotype I and C. ducismarci are genetically distinct from previously described species of Cryptosporidium. Oocysts of Cryptosporidium tortoise genotype I, measuring 5.8-6.9 µm × 5.3-6.5 µm, are morphologically distinguishable from C. ducismarci, measuring 4.4-5.4 µm × 4.3-5.3 µm. Oocysts of Cryptosporidium tortoise genotype I and C. ducismarci obtained from naturally infected Russian tortoises (Testudo horsfieldii Gray) were infectious for the same tortoise but not for Reeve's turtles (Mauremys reevesii [Gray]), common garter snake (Thamnophis sirtalis [Linnaeus]), zebra finches (Taeniopygia guttata [Vieillot]) and SCID mice (Mus musculus Linnaeus). The prepatent period was 11 and 6 days post infection (DPI) for Cryptosporidium tortoise genotype I and C. ducismarci, respectively; the patent period was longer than 200 days for both cryptosporidia. Naturally or experimentally infected tortoises showed no clinical signs of disease. Our morphological, genetic, and biological data support the establishment of Cryptosporidium tortoise genotype I as a new species, Cryptosporidium testudinis sp. n., and confirm the validity of C. ducismarci as a separate species of the genus Cryptosporidium.

Validation of a new technique to detect Cryptosporidium spp. oocysts in bovine feces

Due to its important zoonotic potential, cryptosporidiosis arouses strong interest in the scientific community, because, it was initially considered a rare and opportunistic disease. The parasitological diagnosis of the causative agent of this disease, the protozoan Cryptosporidium spp., requires the use of specific techniques of concentration and permanent staining, which are laborious and costly, and are difficult to use in routine laboratory tests. In view of the above, we conducted the feasibility, development, evaluation and intralaboratory validation of a new parasitological technique for analysis in optical microscopy of Cryptosporidium spp. oocysts, called TF-Test Coccidia, using fecal samples from calves from the city of Araçatuba, São Paulo. To confirm the aforementioned parasite and prove the diagnostic efficiency of the new technique, we used two established methodologies in the scientific literature: parasite concentration by centrifugal sedimentation and negative staining with malachite green (CSN-Malachite) and Nested-PCR. We observed good effectiveness of the TF-Test Coccidia technique, being statistically equivalent to CSN-Malachite. Thus, we verified the effectiveness of the TF-Test Coccidia parasitological technique for the detection of Cryptosporidium spp. oocysts and observed good concentration and morphology of the parasite, with a low amount of debris in the fecal smear.

Prevalence and Genetic Characterization of Cryptosporidium Species in Dairy Calves in Central Ethiopia

The burden of cryptosporidiosis due to Cryptosporidium parvum is well documented in HIV-positive patients in Ethiopia. However, the role of animals in zoonotic transmission of the disease is poorly understood. The aim of this study was to determine the prevalence and genotypes of Cryptosporidium species in dairy calves; to assess the role of cattle in zoonotic transmission in central Ethiopia. A total of 449 fecal samples were collected and screened using modified Ziehl-Neelson staining method and PCR targeting the small-subunit (SSU) rRNA gene. The prevalence of Cryptosporidium was 9.4% (42/449) and 15.8% (71/449) as detected by microscopy and nested PCR, respectively. The prevalence of infection varied significantly across the study areas with the higher prevalence being observed in Chancho 25.4% (30/118). Crossbred calves had significantly higher prevalence of Cryptosporidium than indigenous zebu. Genotyping results revealed the presence of C. andersoni (76.1%), C. bovis (19.7%) and C. ryanae (4.2%). The occurrence of these Cryptosporidium species appeared to be age-related. C. andersoni constituted 92.1% of the Cryptosporidium infection in calves older than 3 months. Sequence analysis also showed the existence of intra-species variation at SSU rRNA gene. Findings of the current study indicate that cattle may not be an important source of zoonotic cryptosporidiosis in central Ethiopia. Further molecular studies are needed to support this observation from other part of the country.

Cryptosporidium avium n. sp. (Apicomplexa: Cryptosporidiidae) in birds

The morphological, biological, and molecular characteristics of Cryptosporidium avian genotype V are described, and the species name Cryptosporidium avium is proposed to reflect its specificity for birds under natural and experimental conditions. Oocysts of C. avium measured 5.30-6.90 μm (mean = 6.26 μm) × 4.30-5.50 μm (mean = 4.86 μm) with a length to width ratio of 1.29 (1.14-1.47). Oocysts of C. avium obtained from four naturally infected red-crowned parakeets (Cyanoramphus novaezealandiae) were infectious for 6-month-old budgerigars (Melopsittacus undulatus) and hens (Gallus gallus f. domestica). The prepatent periods in both susceptible bird species was 11 days postinfection (DPI). The infection intensity of C. avium in budgerigars and hens was low, with a maximum intensity of 5000 oocysts per gram of feces. Oocysts of C. avium were microscopically detected at only 12-16 DPI in hens and 12 DPI in budgerigars, while PCR analyses revealed the presence of specific DNA in fecal samples from 11 to 30 DPI (the conclusion of the experiment). Cryptosporidium avium was not infectious for 8-week-old SCID and BALB/c mice (Mus musculus). Naturally or experimentally infected birds showed no clinical signs of cryptosporidiosis, and no pathology was detected. Developmental stages of C. avium were detected in the ileum and cecum using scanning electron microscopy. Phylogenetic analyses based on small subunit rRNA, actin, and heat shock protein 70 gene sequences revealed that C. avium is genetically distinct from previously described Cryptosporidium species.

Molecular analysis of Cryptosporidium from cattle from five states of Peninsular Malaysia

Despite the importance of the cattle industry in Malaysia, there are very few studies of the diversity and public health significance of bovine cryptosporidiosis in this country. In the present study, we used a PCR-based approach to detect and genetically characterize Cryptosporidium DNA in faecal samples from a cohort of 215 asymptomatic cattle (of different ages) from six farms from five states of Peninsular Malaysia. Cattle on four of the six farms were test-positive for Cryptosporidium, with an overall prevalence of 3.2%. Cryptosporidium bovis and Cryptosporidium ryanae were detected in two (0.9%) and five (2.3%) samples tested; this low prevalence likely relates to the age of the cattle tested, as most (73%) of the samples tested originated from cattle that were ≥2 years of age. Future studies should investigate the zoonotic potential of Cryptosporidium in pre-weaned and weaned calves in rural communities of Malaysia.

Public health significance of zoonotic Cryptosporidium species in wildlife: Critical insights into better drinking water management

Cryptosporidium is an enteric parasite that is transmitted via the faecal-oral route, water and food. Humans, wildlife and domestic livestock all potentially contribute Cryptosporidium to surface waters. Human encroachment into natural ecosystems has led to an increase in interactions between humans, domestic animals and wildlife populations. Increasing numbers of zoonotic diseases and spill over/back of zoonotic pathogens is a consequence of this anthropogenic disturbance. Drinking water catchments and water reservoir areas have been at the front line of this conflict as they can be easily contaminated by zoonotic waterborne pathogens. Therefore, the epidemiology of zoonotic species of Cryptosporidium in free-ranging and captive wildlife is of increasing importance. This review focuses on zoonotic Cryptosporidium species reported in global wildlife populations to date, and highlights their significance for public health and the water industry.

Cryptosporidium rubeyi n. sp. (Apicomplexa: Cryptosporidiidae) in multiple Spermophilus ground squirrel species

Previously we reported the unique Cryptosporidium sp. "c" genotype (e.g., Sbey03c, Sbey05c, Sbld05c, Sltl05c) from three species of Spermophilus ground squirrel (Spermophilus beecheyi, Spermophilus beldingi, Spermophilus lateralis) located throughout California, USA. This follow-up work characterizes the morphology and animal infectivity of this novel genotype as the final step in proposing it as a new species of Cryptosporidium. Analysis of sequences of 18S rRNA, actin, and HSP70 genes of additional Cryptosporidium isolates from recently sampled California ground squirrels (S. beecheyi) confirms the presence of the unique Sbey-c genotype in S. beecheyi. Phylogenetic and BLAST analysis indicates that the c-genotype in Spermophilus ground squirrels is distinct from Cryptosporidium species/genotypes from other host species currently available in GenBank. We propose to name this c-genotype found in Spermophilus ground squirrels as Cryptosporidium rubeyi n. sp. The mean size of C. rubeyi n. sp. oocysts is 4.67 (4.4-5.0) μm × 4.34 (4.0-5.0) μm, with a length/width index of 1.08 (n = 220). Oocysts of C. rubeyi n. sp. are not infectious to neonatal BALB/c mice and Holstein calves. GenBank accession numbers for C. rubeyi n. sp. are DQ295012, AY462233, and KM010224 for the 18S rRNA gene, KM010227 for the actin gene, and KM010229 for the HSP70 gene.

First Molecular Characterization of Cryptosporidium spp. Infecting Buffalo Calves in Brazil

With the aim of determining the occurrence of Cryptosporidium spp., 222 fecal samples were collected from Murrah buffalo calves aged up to 6 mo. Fecal DNA was genotyped with a nested polymerase chain reaction targeting the 18S rRNA gene and sequencing of the amplified fragment. Nested 18S PCR was positive for 48.2% of the samples. Sequence analysis showed that the most frequent species in these animals was Cryptosporidium ryanae, which was present in buffalo calves as young as 5 d. The zoonotic species Cryptosporidium parvum was detected in one animal. An uncommon Cryptosporidium 18S genotype was found in buffaloes.

Cross sectional study of prevalence, genetic diversity and zoonotic potential of Cryptosporidium parvum cycling in New Zealand dairy farms

BACKGROUND

The estimation of the prevalence and zoonotic potential of Cryptosporidium parvum cycling in bovine populations requires the use of genotyping, as several morphologically similar non-parvum genetic variants of unproven clinical and public health impact are found in cattle. However, robust C. parvum prevalence estimates in cattle are lacking and comparative data of bovine and human isolates collected from the same regions are scarce. Thus, the relative contribution of the C. parvum oocysts released by farmed animals to animal and human cryptosporidiosis burden is, in general, poorly understood.

METHODS

The New Zealand farm-level C. parvum prevalence was estimated using a cross-sectional sample of 1283 faecal specimens collected from newborn calves on 97 dairy farms. Faeces were analysed by immunofluorescence and the Cryptosporidium parasites were genetically identified. Finally, bovine C. parvum were genetically compared with historical human clinical isolates using a bilocus subtyping scheme.

RESULTS

Immunofluoresence-positive faeces were found in 63/97 (65%) farms. C. parvum was identified in 49 (50.5%) farms, C. bovis in 6 (6.1%) farms, and on 8 (8.2%) farms the species could not be identified. The dominant C. parvum genetic variants were geographically widespread and found in both host populations, but several variants were found in humans only.

CONCLUSIONS

Phenotypic tests offered by New Zealand veterinary diagnostic laboratories for the diagnosis of C. parvum may have moderate to high positive predictive values for this species. The genetic similarities observed between the human and bovine parasites support a model considering calves as significant amplifiers of zoonotic C. parvum in New Zealand. However, data suggest that transmission routes not associated with dairy cattle should also be taken into account in future source-attribution studies of human cryptosporidiosis.

A perspective on Cryptosporidium and Giardia, with an emphasis on bovines and recent epidemiological findings

Cryptosporidium and Giardia are two common aetiological agents of infectious enteritis in humans and animals worldwide. These parasitic protists are usually transmitted by the faecal-oral route, following the ingestion of infective stages (oocysts or cysts). An essential component of the control of these parasitic infections, from a public health perspective, is an understanding of the sources and routes of transmission in different geographical regions. Bovines are considered potential sources of infection for humans, because species and genotypes of Cryptosporidium and Giardia infecting humans have also been isolated from cattle in molecular parasitological studies. However, species and genotypes of Cryptosporidium and Giardia of bovids, and the extent of zoonotic transmission in different geographical regions in the world, are still relatively poorly understood. The purpose of this article is to (1) provide a brief background on Cryptosporidium and Giardia, (2) review some key aspects of the molecular epidemiology of cryptosporidiosis and giardiasis in animals, with an emphasis on bovines, (3) summarize research of Cryptosporidium and Giardia from cattle and water buffaloes in parts of Australasia and Sri Lanka, considering public health aspects and (4) provide a perspective on future avenues of study. Recent studies reinforce that bovines harbour Cryptosporidium and Giardia that likely pose a human health risk and highlight the need for future investigations of the biology, population genetics and transmission dynamics of Cryptosporidium and Giardia in cattle, water buffaloes and other ruminants in different geographical regions, the fate and transport of infective stages following their release into the environment, as well as for improved strategies for the control and prevention of cryptosporidiosis and giardiasis, guided by molecular epidemiological studies.

Cryptosporidium species in humans and animals: current understanding and research needs

Cryptosporidiumis increasingly recognized as one of the major causes of moderate to severe diarrhoea in developing countries. With treatment options limited, control relies on knowledge of the biology and transmission of the members of the genus responsible for disease. Currently, 26 species are recognized as valid on the basis of morphological, biological and molecular data. Of the nearly 20Cryptosporidiumspecies and genotypes that have been reported in humans,Cryptosporidium hominisandCryptosporidium parvumare responsible for the majority of infections. Livestock, particularly cattle, are one of the most important reservoirs of zoonotic infections. Domesticated and wild animals can each be infected with severalCryptosporidiumspecies or genotypes that have only a narrow host range and therefore have no major public health significance. Recent advances in next-generation sequencing techniques will significantly improve our understanding of the taxonomy and transmission ofCryptosporidiumspecies, and the investigation of outbreaks and monitoring of emerging and virulent subtypes. Important research gaps remain including a lack of subtyping tools for manyCryptosporidiumspecies of public and veterinary health importance, and poor understanding of the genetic determinants of host specificity ofCryptosporidiumspecies and impact of climate change on the transmission ofCryptosporidium.

Molecular characterization of Cryptosporidium isolates from beef calves under one month of age over three successive years in one herd in western France

Cohorts of pre-weaned calves were studied for Cryptosporidium infection over three successive years (2010–2012) in one beef cattle herd in western France. Each year 25–34 calves were sampled weekly from 3 days to one month of age in order to characterize oocyst output, Cryptosporidium species and clinical features associated with infection. Faecal samples were screened for the presence of oocysts using immunofluorescence analysis. DNA was extracted from positive samples and a PCR SSU rRNA followed by RFLP or sequencing was performed. For the subtyping of C. parvum, a gp60 PCR was carried out. Regardless of the year, 92–100% of the animals excreted oocysts on at least one sampling date. Depending on the year of observation, the age of highest prevalence varied. In contrast, the peak of excretion was systematically observed almost at the same age (2nd–3rd week of life) with excretion levels ranging from between 100 and 1.7 × 10⁷ oocysts/g of faeces. Differences concerning clinical signs depending on the year of sampling were observed. Different species patterns were observed, with a predominance of C. bovis in the 1st year and a predominance of C. parvum in the last year. Moreover, two zoonotic subtypes of C. parvum, IIaA15G2R1 and IIaA18G2R1, were recorded in different years. This study shows that, in a given farm, the Cryptosporidium species and C. parvum subtypes identified as well as the prevalence of infection and level of excretion may vary greatly and show distinct patterns according to the year.