Distribution of Cryptosporidium parvum subtypes in calves in eastern United States

Prevalence, risk factors and molecular epidemiology of neonatal cryptosporidiosis in calves: The Argentine perspective

Cryptosporidium spp. are enteroparasitic protozoans that cause cryptosporidiosis in newborn calves. Clinical signs of the infection are diarrhoea and dehydration leading to decreased productivity and economic losses in cattle farms around the world. Additionally, cryptosporidiosis is a relevant zoonotic disease since the ingestion of oocysts can be fatal for children under five years of age, the elderly, and/or immunocompromised adults. This review aims to integrate existing knowledge on the epidemiological situation of calf cryptosporidiosis and associated risk factors in Argentina. In addition, the GP60 subtype diversity of the pathogen was analysed and related with the global distribution of corresponding GP60 subtypes. Depending on the study region and applied diagnostics, prevalence among calves up to 20 days of age varied between 25.2% and 42.5%, while a prevalence of 16.3-25.5% was observed at the age of 1-90 days. So far, molecular studies have determined exclusively Cryptosporidium parvum in preweaned calves. In addition, C. parvum infection was reported as the major cause of calf diarrhoea, followed by rotavirus A (RVA), while enteropathogens such as coronavirus, Escherichiacoli, and Salmonella sp. played a negligible role. Calf age of 20 days or less, incidence of diarrhoea, poorly drained soils, and large farm size were identified as risk factors for C. parvum-infection in Argentina. A total of nine GP60 subtypes (IIaAxxG1R1, xx = 16 to 24) were identified, showing a stepwise increase of the trinucleotide motif TCA, and including the zoonotic subtypes IIaA16G1R1, IIaA17G1R1, IIaA18G1R1, IIaA19G1R1, and IIaA20G1R1. We found that an increase in the A16→A24 trinucleotide repeat was accompanied by a gradual decrease in the global distribution of GP60 alleles, strongly suggesting that IIaA16G1R1 represents the primordial allelic variant of this group. Since identified GP60 alleles have a similar genetic background, we hypothesize that the continuous trinucleotide repeat array has been generated by stepwise repeat expansion of A16. The information gathered and integrated in this study contributes to an improved understanding of the epidemiological characteristics of bovine cryptosporidiosis in and beyond Argentina, which in turn can help to develop control strategies for this parasitosis of veterinary and medical relevance.

Distribution of Cryptosporidium parvum subgenotypes in pre-weaned calves in Germany

Cryptosporidium parvum is a main cause of severe diarrhea in young calves leading to economic loss and animal suffering. Little is known about the epidemiology of the genetic subtypes that may differ in their infectiousness and zoonotic potential. The present study analyzes the distribution of Glycoprotein 60 (GP60) variants in C. parvum positive samples obtained from young calves in Germany where individual fecal samples of 441 pre-weaned calves collected from 98 German dairy herds were evaluated for cryptosporidiosis (Göhring et al., 2014). DNA was extracted for Restriction Fragment Length Polymorphism (RFLP) analysis from 268 samples that were positive for Cryptosporidium by coproantigen EIA originating from 91 farms confirming C. parvum as the only species occurring. GP60 subtype analysis revealed 12C. parvum subtypes, all belonging to the zoonotic allele family IIa. The most widespread subtype was IIaA15G2R1 (71.4%). Other subtypes occurred sporadically: IIaA16G2R1, IIaA16G3R1 and IIaA17G2R1 (6.2%), IIaA13G1R2 (3.5%), IIaA14G1R1 (3.1%), IIaA14G2R1 (1.3%), IIaA17G1R1 (0.9%) and IIaA13G2R1, IIaA16G1R2, IIaA17G1R2 and IIaA24G1R1 (0.4%). Altogether a high diversity of subgenotypes was found with IIaA15G2R1 clearly dominating irrespective of geographic region. All subgenotypes are considered zoonotic underscoring that pre-weaned calves are likely to be a reservoir for zoonotic C. parvum and thus may be a risk for animal-to-human transmission.

Cryptosporidium infection in young dogs from Germany

Cryptosporidium is an enteric protozoan parasite which is able to cause severe gastrointestinal disease and is distributed all over the world. Since information about the prevalence of cryptosporidiosis in German dogs is rare, the aim of this study was to examine the occurrence of Cryptosporidium spp. in dogs and the potential zoonotic risk emanating from these infected animals. In total, 349 fecal samples of 171 dogs were collected during the dogs’ first year of life. The samples were examined for Cryptosporidium spp. using PCR, targeting the small subunit ribosomal RNA gene (SSU rRNA). Further analysis of Cryptosporidium parvum and Cryptosporidium canis positive samples was accomplished using the 60 kDa glycoproteine gene (GP60). Overall, 10.0% (35/349) of the specimens were tested positive for Cryptosporidium. Cryptosporidium canis was found in 94.3% (33/35) of these samples and the zoonotic type C. pavum in 5.7% (2/35). Both C. parvum infections were subtyped as IIaA15G2R1. Sixteen of the C. canis positive samples were successfully amplified at the GP60 gene locus. These isolates were identified to belong to the subtype families XXd, XXe, or XXb; however, 2 samples could not be assigned to any of the described subtype families. Considering the close contact between pets and their owners, dogs may act as a potential source of infection for human cryptosporidiosis. The results of this study, in context with other studies from different countries, provide important further insights into the distribution of Cryptosporidium species in dogs and their zoonotic potential.

High Occurrence of Zoonotic Subtypes of Cryptosporidiumparvum in Cypriot Dairy Farms

Cryptosporidium parvum is one of the major causes of neonatal calf diarrhoea resulting in reduced farm productivity and compromised animal welfare worldwide. Livestock act as a major reservoir of this parasite, which can be transmitted to humans directly and/or indirectly, posing a public health risk. Research reports on the prevalence of Cryptosporidium in ruminants from east Mediterranean countries, including Cyprus, are limited. This study is the first to explore the occurrence of Cryptosporidium spp. in cattle up to 24 months old on the island of Cyprus. A total of 242 faecal samples were collected from 10 dairy cattle farms in Cyprus, all of which were screened for Cryptosporidium spp. using nested-PCR amplification targeting the small subunit of the ribosomal RNA (18S rRNA) gene. The 60 kDa glycoprotein (gp60) gene was also sequenced for the samples identified as Cryptosporidium parvum-positive to determine the subtypes present. The occurrence of Cryptosporidium was 43.8% (106/242) with at least one positive isolate in each farm sampled. Cryptosporidium bovis, Cryptosporidium ryanae and C. parvum were the only species identified, while the prevalence per farm ranged from 20–64%. Amongst these, the latter was the predominant species, representing 51.8% of all positive samples, followed by C. bovis (21.7%) and C. ryanae (31.1%). Five C. parvum subtypes were identified, four of which are zoonotic—IIaA14G1R1, IIaA15G1R1, IIaA15G2R1 and IIaA18G2R1. IIaA14G1R1 was the most abundant, representing 48.2% of all C. parvum positive samples, and was also the most widespread. This is the first report of zoonotic subtypes of C. parvum circulating in Cyprus. These results highlight the need for further research into the parasite focusing on its diversity, prevalence, host range and transmission dynamics on the island.

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.

Molecular characterization of Cryptosporidium isolates from humans in Ontario, Canada

BACKGROUND

Cryptosporidiosis is a gastrointestinal disease with global distribution. It has been a reportable disease in Canada since 2000; however, routine molecular surveillance is not conducted. Therefore, sources of contamination are unknown. The aim of this project was to identify species and subtypes of Cryptosporidium in clinical cases from Ontario, the largest province in Canada, representing one third of the Canadian population, in order to understand transmission patterns.

METHODS

A total of 169 frozen, banked, unpreserved stool specimens that were microscopy positive for Cryptosporidium over the period 2008-2017 were characterized using molecular tools. A subset of the 169 specimens were replicate samples from individual cases. DNA was extracted directly from the stool and nested PCR followed by Sanger sequencing was conducted targeting the small subunit ribosomal RNA (SSU) and glycoprotein 60 (gp60) genes.

RESULTS

Molecular typing data and limited demographic data were obtained for 129 cases of cryptosporidiosis. Of these cases, 91 (70.5 %) were due to Cryptosporidium parvum and 24 (18.6%) were due to Cryptosporidium hominis. Mixed infections of C. parvum and C. hominis occurred in four (3.1%) cases. Five other species observed were Cryptosporidium ubiquitum (n = 5), Cryptosporidium felis (n = 2), Cryptosporidium meleagridis (n = 1), Cryptosporidium cuniculus (n = 1) and Cryptosporidium muris (n = 1). Subtyping the gp60 gene revealed 5 allelic families and 17 subtypes of C. hominis and 3 allelic families and 17 subtypes of C. parvum. The most frequent subtype of C. hominis was IbA10G2 (22.3%) and of C. parvum was IIaA15G2R1 (62.4%).

CONCLUSIONS

The majority of isolates in this study were C. parvum, supporting the notion that zoonotic transmission is the main route of cryptosporidiosis transmission in Ontario. Nonetheless, the observation of C. hominis in about a quarter of cases suggests that anthroponotic transmission is also an important contributor to cryptosporidiosis pathogenesis in Ontario.

Cryptosporidium parvum, Cryptosporidium ryanae, and Cryptosporidium bovis in samples from calves in Austria

Fecal samples of 177 calves of up to 180 days of age with diarrhea from 70 farms in Austria were examined to obtain information on the occurrence of Cryptosporidium species. Initially, all samples were examined by phase-contrast microscopy. Cryptosporidium-positive samples (55.4%; n = 98) were screened by gp60 PCR, resulting in 68.4% (n = 67) C. parvum-positive samples. The remaining 31 gp60-PCR-negative and the phase-contrast microscopy negative samples (n = 79) were screened by PCR targeting a 700 bp fragment of the 18S rRNA gene. Sequencing of the PCR products revealed the presence of C. parvum (n = 69), C. ryanae (n = 11), and C. bovis (n = 7). The latter two species have never been described in Austria. C. parvum-positive samples were genotyped at the gp60 gene locus, featuring four subtypes (IIaA15G2R1, IIaA21G2R1, IIaA19G2R1, IIaA14G1R1). The most frequently detected subtype IIaA15G2R1 (n = 52) was present in calves from 30 different farms. IIaA14G1R1 (n = 5) occurred on a single farm, subtype IIaA21G2R1 (n = 4) on two farms, and subtype IIaA19G2R1 (n = 4) on three farms. The results confirm the widespread occurrence of zoonotic C. parvum in diarrheic calves.

Cryptosporidium parvum in brown brocket (Mazama gouazoubira) from Brazil: First report of the subtype IIaA16G3R1 in cervids

This research had as objective to evaluate the occurrence and to characterize genetically the infections by Cryptosporidium in Mazama gouazoubira. By a non-invasive harvest methodology using trained sniffer dogs to locate fecal samples of cervids, 642 fecal samples were obtained from six Brazilian localities. The cervids species responsible for the excretion of each fecal sample were identified by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), using the mitochondrial cytochrome b target gene (cyst b) and the restriction enzymes Sspl, AflIII and BstN. From this identification, 437 fecal samples of M. gouazoubira were selected for research of Cryptosporidium spp. performed through negative staining with malachite green and polymerase chain reaction (nPCR), with the subunit of 18S rRNA gene, followed by sequencing the amplified products. In the samples that were diagnosed the presence of parasite species with zoonotic potential, genotyping was also performed using nPCR with the subunit of GP60 gene. Statistical analysis consisted of the Fisher exact test to verify the association of the presence of the enteroparasite in relation to the presence of cattle in each locality, and the McNemar tests and Kappa correlation coefficient used to compare the results obtained between the two diagnostic techniques. In the fecal samples of M. gouazoubira the occurrences of Cryptosporidium were diagnosed in 1.6% (7/437) and 1.1% (5/437), respectively, through nPCR and microscopy. Cryptosporidium. parvum was diagnosed in 100% (7/7) of the samples submitted to sequencing (18S gene). The IIaA16G3R1 subtype was diagnosed in five of the C. parvum samples submitted to genotyping (GP60 gene). This is the first world report of C. parvum in M. gouazoubira and subtype IIaA16G3R1 in cervids.

Dairy Calves in Uruguay Are Reservoirs of Zoonotic Subtypes of Cryptosporidium parvum and Pose a Potential Risk of Surface Water Contamination

Cryptosporidium parvum, a major cause of diarrhea in calves, is of concern given its zoonotic potential. Numerous outbreaks of human cryptosporidiosis caused by C. parvum genetic subtypes are reported yearly worldwide, with livestock or water being frequently identified sources of infection. Although cryptosporidiosis has been reported from human patients in Uruguay, particularly children, epidemiologic information is scant and the role of cattle as reservoirs of zoonotic subtypes of C. parvum has not been explored. In this study, we aimed to (a)-identify C. parvum subtypes infecting dairy calves in Uruguay (including potentially zoonotic subtypes), (b)-assess their association with calf diarrhea, (c)-evaluate their spatial clustering, and (d)-assess the distance of infected calves to surface watercourses draining the farmlands and determine whether these watercourses flow into public water treatment plants. Feces of 255 calves that had tested positive for Cryptosporidium spp. by antigen ELISA were selected. Samples had been collected from 29 dairy farms in seven Uruguayan departments where dairy farming is concentrated and represented 170 diarrheic and 85 non-diarrheic calves. Selected samples were processed by nested PCRs targeting the 18S rRNA and gp60 genes followed by sequencing to identify C. parvum subtypes. Of seven C. parvum subtypes detected in 166 calves, five (identified in 143 calves on 28/29 farms) had been identified in humans elsewhere and have zoonotic potential. Subtype IIaA15G2R1 was the most frequent (53.6%; 89/166), followed by IIaA20G1R1 (24.1%; 40/166), IIaA22G1R1 (11.4%; 19/166), IIaA23G1R1 (3.6%; 6/166), IIaA17G2R1 (3%; 5/166), IIaA21G1R1 (2.4%; 4/166), and IIaA16G1R1 (1.8%; 3/166). There were no significant differences in the proportions of diarrheic and non-diarrheic calves infected with any of the C. parvum subtypes. Two spatial clusters were detected, one of which overlapped with Uruguay's capital city and its main water treatment plant (Aguas Corrientes), harvesting surface water to supply ~1,700,000 people. Infected calves on all farms were within 20–900 m of a natural surface watercourse draining the farmland, 10 of which flowed into six water treatment plants located 9–108 km downstream. Four watercourses flowed downstream into Aguas Corrientes. Calves are reservoirs of zoonotic C. parvum subtypes in Uruguay and pose a public health risk.

Prevalence and Genotyping of Cryptosporidium parvum in Gastrointestinal Cancer Patients

Gastrointestinal cancers are the most commonly occurring malignancies which contributing to over 1/5 of cancer incidences worldwide. Increasing evidences have shown that Cryptosporidium spp., an apicomplexan protozoan, is highly associated with gastrointestinal cancers. However, the prevalence of Cryptosporidium spp. infections among gastrointestinal cancer patients in China has not been estimated yet. We here performed a case-control study to evaluate the occurrences of Cryptosporidium spp. in patients with digestive malignancies before chemotherapy and in control population. Nested PCR amplifying 18S rRNA gene was used to detect the presence of Cryptosporidium spp. in each fecal sample. The results herein confirmed the correlation of Cryptosporidium spp. infection with colorectal and liver cancers, while first identified the high frequencies of Cryptosporidium spp. in esophageal cancer and small intestine cancer. The infection rates of Cryptosporidium spp. in colorectal, esophageal, liver and small intestine cancers were 17.24% (20/116, P<0.001), 6.25% (1/16, P=0.029), 14.29% (1/7, P<0.001) and 40% (2/5, P<0.001), respectively. In addition, molecular characterization indicated that all the Cryptosporidium spp. obtained were Cryptosporidium parvum (C. parvum), and the 18S rRNA sequences were identical to the reference sequences isolated from cattle, suggesting potential zoonotic transmission. Furthermore, subtyping analyses revealed that IIaA15G2R1 and IIaA15G2R2 were the predominant subtypes in colorectal cancer, while IIaA13G2R2 subtype was first named and identified in colorectal and liver cancers. Taken together, for the first time, the prevalence of Cryptosporidium spp. infections in digestive cancer patients has been estimated among Chinese. Our results indicated that C. parvum were highly associated with gastrointestinal cancers, supporting that cryptosporidiosis could be a potential risk factor for these diseases.

Cryptosporidium spp.: Human incidence, molecular characterization and associated exposures in Québec, Canada (2016-2017)

The aim of this study was to describe the epidemiology of human cryptosporidiosis in Québec from 2016 to 2017 and to identify possible exposures associated with the disease, and the dominant Cryptosporidium species in circulation. A descriptive analysis was performed on data collected from the provincial notifiable infectious diseases registry and the epidemiological investigation. Fecal sample were sent to the Laboratoire de santé publique du Québec for molecular characterization. In Québec, from January 1, 2016 to December 31, 2017, a total of 201 confirmed cases of cryptosporidiosis were notified. A peak in the number of reported cases was observed at the end of the summer. The regional public health department with the highest adjusted incidence rate for sex and age group for both years was that of Nunavik, in the north of Québec. A higher average annual incidence rate was observed for females between the ages of 20 to 34 years compared to males. Overall, for both males and females the distribution appeared to be bimodal with a first peak in children younger than five years old and a second peak in adults from 20 to 30 years of age. Molecular characterization showed that 23% (11/47) of cases were infected with C. hominis while 74% (35/47) were infected with C. parvum. Meanwhile, subtyping results identified by gp60 sequencing, show that all C. parvum subtypes belonged to the IIa family, whereas the subtypes for C. hominis belonged to the Ia, Ib, and Id families. Finally, the epidemiological investigation showed that diarrhea was the most common reported symptom with 99% (72/73) of investigated cases having experienced it. This first brief epidemiological portrait of cryptosporidiosis in Québec has allowed for the description, both at the provincial and regional level, of the populations that could be particularly vulnerable to the disease.

Molecular characterization of Cryptosporidium isolates from diarrheal dairy calves in France

Cryptosporidium is an obligate intracellular protist parasite infecting a wide range of vertebrate hosts and causes significant intestinal disease in both animals and humans, as some species are zoonotic. Cattle and especially calves have been identified as one of the most common reservoirs of this protist. However, little is known about the genetics of Cryptosporidium in calves in some regions of France. The aim of this study was to detect and isolate Cryptosporidium spp. in faecal samples from naturally infected pre-weaned calves (≤45 days-old) in France. A total of 35 diarrhoeic pre-weaned calf faecal samples were collected from 26 dairy cattle farms in six departments (French administrative provinces). Cryptosporidium presence was established by microscopically screening samples for oocystes with an immunofluorescent (DFA) staining method. DFA-positive samples were then analysed by PCR-RFLP and 18S rRNA gene sequencing to determine species. Cryptosporidium parvum-positive samples were subtyped via nested PCR analysis of a partial fragment of the 60 kDa glycoprotein (gp60) gene product. Data were then integrated into phylogenetic tree analysis. DFA revealed the presence of Cryptosporidium oocysts in 31 out of 35 (88%) samples. Combined with 18S rRNA gene analysis results, C. parvum was detected in 30 samples. Subtyping analysis in 27/30 samples (90%) of the C. parvum isolates revealed two zoonotic subtype families, IIa (24/27) and IId (3/27). Four subtypes were recognised within the subtype family IIa, including the hypertransmissible IIaA15G2R1 subtype that is the most frequently reported worldwide (21/27), IIaA17G3R1 (1/27), IIaA17G1R1 (1/27), and IIaA19G1R1 (1/27). Two subtypes were recognised within the IId subtype family including IIdA22G1 (2/27) and IIdA27G1 (1/27). These findings illustrate the high occurrence of Cryptosporidium in calves in dairy herds and increase the diversity of molecularly characterised C. parvum isolates with the first description of IIaA17G3R1, IIaA19G1R1, and IId subtypes in France. The presence of zoonotic C. parvum subtype families (IIa, IId) in this study suggests that pre-weaned calves are likely to be a significant reservoir of zoonotic C. parvum, and highlights the importance of animal to human cryptosporidiosis transmission risk. Further molecular studies in calves and small ruminants from other French regions are required to better understand the epidemiology of cryptosporidiosis in France.

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Faecal samples from pre-weaned diarrheal calves were analysed

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Cryptosporidium spp. was detected in 30 samples out of 35.

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C. parvum was the only species identified

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Two zoonotic subtype families were identified: IIa and IId

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The hyper-transmissible IIaA15G2R1 was the dominant C. parvum subtype

Molecular characterization of Giardia intestinalis and Cryptosporidium parvum from calves with diarrhoea in Austria and evaluation of point-of-care tests

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Giardia intestinalis (48/177) and Cryptosporidium parvum (98/177) occur in Austrian calves.

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C. parvum genotypes IIaA15G2R1, IIaA19G2R2, IIaA21G2R1 and IIaA14G1R1 were found.

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Giardia intestinalis assemblage E and a single sample of assemblage A were found.

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Cryptosporidium was detected mostly in the first two weeks of age (72/102).

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Point-of-care test validity varied greatly for Giardia and Cryptosporidium.

To obtain information about the occurrence and genotype distribution of G. intestinalis and C. parvum in Austrian cattle, faecal samples from diarrhoeic calves younger than 180 days of age originating from 70 farms were examined. Of the 177 faecal samples, 27.1% were positive for Giardia cysts (immunofluorescence microscopy) and 55.4% for Cryptosporidium oocysts (phase-contrast microscopy). Positive samples were characterized by nested PCR for Giardia, 83.3% (triosephosphate isomerase; tpi) and 89.6% (β-giardin; bg) were positive, while the Cryptosporidium nested PCR returned 92.5% (60-kDa glycoprotein) positive results. Sequence analysis revealed one assemblage A-positive sample and 30 (bg) respectively 29 (tpi) assemblage E-positive samples for G. intestinalis. For C. parvum four subtypes within the IIa family (IIaA15G2R1, n = 29; IIaA19G2R2, n = 3; IIaA21G2R1, n = 2; IIaA14G1R1, n = 1) could be differentiated. Validation of two immunochromatographic point-of-care tests resulted in a sensitivity of 29.2% and 77.6%; a specificity of 98.4% and 91.1% for the detection of Giardia intestinalis and Cryptosporidium parvum, respectively. Results confirm the widespread occurrence of both protozoa in diarrhoeic calves in Austria.

An investigation of dairy calf management practices, colostrum quality, failure of transfer of passive immunity, and occurrence of enteropathogens among Australian dairy farms

Calf preweaning morbidity and mortality risks have been reported as high in several countries, with average values approximating 35 and 7%, respectively. However, limited data are available for calf morbidity and mortality risks on Australian dairy farms. The aims of this study were (1) to investigate current calf management practices on dairy farms in Australia and their association with herd-level morbidity and mortality using a questionnaire-based, cross-sectional study; and (2) to estimate the prevalence of common enteropathogens causing diarrhea, the failure of passive transfer of immunity, and poor colostrum quality in a sample of Australian dairy farms. We analyzed 106 completed questionnaires and samples from 23 farms (202 fecal, 253 calf serum, and 221 colostrum samples). Morbidity and mortality risks reported by farmers in preweaned heifers were 23.8 and 5.6%, respectively. These risks were above the Australian dairy industry targets in 75.5 and 66.7% of respondents. The zoonotic pathogens Cryptosporidium spp. and Salmonella spp. were the most prevalent enteropathogens, with a true prevalence of 40.9 and 25.2%, respectively. Salmonella O-group D was present in 67.9% of Salmonella-positive samples, followed by O-groups B (17.9%) and C (10.7%). Failure of transfer of passive immunity (IgG <10 g/L) was observed in 41.9% of calves (mean herd-level prevalence of 36.2%), and only 19.5% of colostrum samples met the standards for immunoglobulin content and microbiological quality. Collectively, these data indicate that there is still considerable room for improvement in calf-rearing practices on Australian dairy farms, particularly with regard to colostrum management and feeding hygiene.

Isolation, genotyping and subtyping of single Cryptosporidium oocysts from calves with special reference to zoonotic significance

The ability of the small-subunit ribosomal RNA (SSU rRNA) based nested PCR and Restriction Fragment Length Polymorphism (PCR-RFLP) to identify and genotype a single Cryptosporidium oocyst isolated from bovine faecal samples was evaluated in this study. In addition, subtyping was carried out by sequencing the 60 kDa glycoprotein (gp60) gene from the same single oocyst. Faecal samples were collected from 40 pre-weaned calves (5-20 days old) from 7 dairy farms located in 3 different counties within the Finger Lakes region of Upstate New York. All the samples were microscopically positive for Cryptosporidium spp. A total of 400 Cryptosporidium oocysts (10 single oocysts from each calf sample) were individually isolated and analyzed using a nested PCR targeting the SSU rRNA gene. The SSU rRNA gene was amplified in 324 (81%) individual oocysts. All SSU rRNA amplified individual oocysts DNA was genotyped using PCR-RFLP. C. parvum was the only identified species; 107 single oocysts generated PCR products from the A gene, 18 generated PCR products from the B gene and 199 generated PCR products from both. Sequence analysis of the gp60 gene in 99 individual oocysts revealed the presence of only subtype IIaA15G2R1 with 99.4-100% and 99.1-100% identity of nucleotides and amino acids, respectively. These sequences were identical (100%) in oocysts from 35 calves and exhibited mutations in the non-repeat region of the gp60 gene in those of 5 other calves. The examination of DNA from individual oocysts with genotyping and subtyping tools provides methodology to more clearly define the genetic characteristics of Cryptosporidium spp. on farms and within individual animals.

A protocol to count Cryptosporidium oocysts by flow cytometry without antibody staining

Cryptosporidiosis caused by the protozoan parasites Cryptosporidium hominis and C. parvum, threatens the lives of young children in developing countries. In veterinary medicine, C. parvum causes life-threatening diarrhea and dehydration in newborn dairy calves. Protocols to detect Cryptosporidium spp. oocysts using flow cytometry have been reported; however, these protocols use antibodies against the parasite and typically focus on detection of oocysts, not quantification. These techniques are not well-suited for studies that generate large variations in oocyst burdens because the amount of antibody required is proportional to the number of oocysts expected in samples. Also, oocysts are lost in washes in the staining protocol, reducing accuracy of oocyst counts. Moreover, these protocols require costly fluorochrome-conjugated monoclonal antibodies and are not optimal for studies involving large numbers of samples. Here we present an optimized protocol for purifying oocysts from mouse stool and intestine samples combined with a reliable method to quantify oocysts in a relatively pure population without the need for antibody staining. We used morphology (SSC-A vs FSC-A) and the innate characteristics of C. parvum oocysts compared to fecal and intestinal contaminants to develop a two-step gating strategy that can differentiate oocysts from debris. This method is a fast, reliable, and high-throughput technique to promote research projects on C. parvum infections in mice and potentially other animal hosts.

Diarrheal diseases are the second leading cause of death in children < 5 years old. Cryptosporidiosis caused by the unicellular parasite Cryptosporidium spp. is one of these diarrheal diseases. C. hominis and C. parvum cause moderate-to-severe diarrhea and dehydration that threaten the lives of young children in developing countries. Flow cytometry is a state-of-the-art technique to detect Cryptosporidium spp. oocysts, the infectious form of the parasite. Reported protocols typically focus on detection of oocysts using antibody staining. However, these techniques present several complications: oocysts are lost in washes used in the staining protocol and the amount of antibody required is proportional to the number of oocysts expected in samples; thus, parasite burden needs first to be estimated by optical microscopy. In addition, these protocols require costly antibodies. We developed a reliable method to quantify Cryptosporidium spp. oocysts in a relatively pure population without the need for antibody staining. We used known characteristics of the structure of oocysts to develop a strategy that can differentiate oocysts from debris. This method is fast, affordable and reliable and will facilitate pre-clinical projects on interventions to treat or prevent Cryptosporidium spp. infection.

Distribution of Cryptosporidium parvum gp60 subtypes in calf herds of Saxony, Germany

Cryptosporidiosis is a common protozoan parasitic infection that causes diarrhoea in neonatal calves. The high shedding of environmentally resistant oocysts facilitates outbreaks of cryptosporidiosis in humans. In total, 58 farms (512 calves) in Germany (Saxony and Brandenburg) were visited three times each. Faecal samples of pre-weaned calves were microscopically examined for oocysts of Cryptosporidium spp. using Heine staining and were scored with regard to their consistency. Overall, 88.9% of calves tested microscopically positive for Cryptosporidium spp. in at least one sample, and the excretion of oocysts was significantly (P < 0.01) associated with a higher faecal score (diarrhoea). After DNA extraction from pooled farm isolates, 47 samples were successfully subtyped by sequence analysis of the 60 kDa glycoprotein gene (gp60). All isolates belonged to subtype family IIa. IIaA15G2R1 was the most common subtype (present on 66% of the farms), followed by IIaA16G3R1 (13%). Subtypes IIaA14G1R1, IIaA14G2R1, IIaA1612R1, IIaA16G2R1, IIaA17G1R1, IIaA17G2R1, IIaA17G4R1 and IIaA19G2R1 were found sporadically. This is the first description of gp60 subtype IIaA17G4R1 in cattle in Germany.

First report of Cryptosporidium parvum in a dromedary camel calf from Western Australia

Cryptosporidium is an important enteric parasite that can contribute large numbers of infectious oocysts to drinking water catchments. As a result of its resistance to disinfectants including chlorine, it has been responsible for numerous waterborne outbreaks of gastroenteritis. Wildlife and livestock play an important role in the transmission of Cryptosporidium in the environment. Studies conducted outside Australia have indicated that camels may also play a role in the transmission of zoonotic species of Cryptosporidium. Despite Australia being home to the world's largest camel herd, nothing is known about the prevalence and species of Cryptosporidium infecting camels in this country. In the present study, C. parvum was identified by PCR amplification and sequencing of a formalin-fixed intestinal tissue specimen from a one-week old dromedary camel (Camelus dromedarius). Subtyping analysis at the glycoprotein 60 (gp60) locus identified C. parvum subtype IIaA17G2R1, which is a common zoonotic subtype reported in humans and animals worldwide. Histopathological findings also confirmed the presence of large numbers of variably-sized (1-3 µm in diameter) circular basophilic protozoa - consistent with Cryptosporidium spp.- adherent to the mucosal surface and occasionally free within the lumen. Further analysis of the prevalence and species of Cryptosporidium in camel populations across Australia are essential to better understand their potential for contamination of drinking water catchments.

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in deer in Henan and Jilin, China

Background

Little is known about the prevalence and zoonotic potential of Cryptosporidium spp. and Giardia duodenalis in deer in China. In this study, 662 fecal samples were collected from 11 farms in Henan and Jilin Provinces between July 2013 and August 2014, and were screened for the presence of Cryptosporidium and G. duodenalis with genotyping and subtyping methods.

Results

Cryptosporidium spp. and G. duodenalis were detected in 6.80% (45/662) and 1.21% (5/662) of samples, respectively. Six Cryptosporidium species/genotypes were identified based on the small subunit ribosomal ribonucleic acid (SSU rRNA) gene: C. parvum (n = 11); C. andersoni (n = 5); C. ubiquitum (n = 3); C. muris (n = 1); C. suis-like (n = 1); and Cryptosporidium deer genotype (n = 24). When five of the 11 C. parvum isolates were subtyped by sequencing the 60 kDa glycoprotein (gp60) gene, zoonotic subtypes IIaA15G2R2 (n = 4) and IIdA19G1 (n = 1) were found. According to a subtype analysis, three C. ubiquitum isolates belonged to XIIa subtype 2. In contrast, only assemblage E was detected in the five Giardia-positive samples with small subunit ribosomal ribonucleic acid (SSU rRNA) gene sequencing.

Conclusions

To our knowledge, this is the first study to report C. andersoni, as well as C. parvum zoonotic subtypes IIaA15G2R2 and IIdA19G1 in cervids. These data, though limited, suggest that cervids may be a source of zoonotic Cryptosporidium and Giardia. Cervids in the present study are likely to be of low zoonotic potential to humans, and more molecular epidemiological studies are required to clarify the prevalence and public health significance of Cryptosporidium and G. duodenalis in cervids throughout China.

Lessons Learned from Protective Immune Responses to Optimize Vaccines against Cryptosporidiosis

In developing countries, cryptosporidiosis causes moderate-to-severe diarrhea and kills thousands of infants and toddlers annually. Drinking and recreational water contaminated with Cryptosporidium spp. oocysts has led to waterborne outbreaks in developed countries. A competent immune system is necessary to clear this parasitic infection. A better understanding of the immune responses required to prevent or limit infection by this protozoan parasite is the cornerstone of development of an effective vaccine. In this light, lessons learned from previously developed vaccines against Cryptosporidium spp. are at the foundation for development of better next-generation vaccines. In this review, we summarize the immune responses elicited by naturally and experimentally-induced Cryptosporidium spp. infection and by several experimental vaccines in various animal models. Our aim is to increase awareness about the immune responses that underlie protection against cryptosporidiosis and to encourage promotion of these immune responses as a key strategy for vaccine development. Innate and mucosal immunity will be addressed as well as adaptive immunity, with an emphasis on the balance between T_H1/T_H2 immune responses. Development of more effective vaccines against cryptosporidiosis is needed to prevent Cryptosporidium spp.-related deaths in infants and toddlers in developing countries.

Molecular epidemiologic tools for waterborne pathogens Cryptosporidium spp. and Giardia duodenalis

Molecular diagnostic tools have played an important role in improving our understanding of the transmission of Cryptosporidium spp. and Giardia duodenalis, which are two of the most important waterborne parasites in industrialized nations. Genotyping tools are frequently used in the identification of host-adapted Cryptosporidium species and G. duodenalis assemblages, allowing the assessment of infection sources in humans and public health potential of parasites found in animals and the environment. In contrast, subtyping tools are more often used in case linkages, advanced tracking of infections sources, and assessment of disease burdens attributable to anthroponotic and zoonotic transmission. More recently, multilocus typing tools have been developed for population genetic characterizations of transmission dynamics and delineation of mechanisms for the emergence of virulent subtypes. With the recent development in next generation sequencing techniques, whole genome sequencing and comparative genomic analysis are increasingly used in characterizing Cryptosporidium spp. and G. duodenalis. The use of these tools in epidemiologic studies has identified significant differences in the transmission of Cryptosporidium spp. in humans between developing countries and industrialized nations, especially the role of zoonotic transmission in human infection. Geographic differences are also present in the distribution of G. duodenalis assemblages A and B in humans. In contrast, there is little evidence for widespread zoonotic transmission of giardiasis in both developing and industrialized countries. Differences in virulence have been identified among Cryptosporidium species and subtypes, and possibly between G. duodenalis assemblages A and B, and genetic recombination has been identified as one mechanism for the emergence of virulent C. hominis subtypes. These recent advances are providing insight into the epidemiology of waterborne protozoan parasites in both developing and developed countries.

Prevalence of Cryptosporidium species and subtypes in paediatric oncology and non-oncology patients with diarrhoea in Jordan

Cryptosporidiosis is a protozoan parasitic disease which affects human and animals worldwide. In adult immunocompetent individuals, cryptosporidiosis usually results in acute and self-limited diarrhoea; however, it can cause life threatening diarrhoea in children and immunocompromised individuals. In the present study, we compared the prevalence of Cryptosporidium species and gp60 subtypes amongst paediatric oncology patients with diarrhoea (n=160) from King Hussein Medical Centre for Cancer in Jordan, and non-oncology paediatric patients with diarrhoea (n=137) from Al-Mafraq paediatric hospital. Microscopy results using modified acid fast staining identified a significantly (p≤0.05) higher prevalence of Cryptosporidium in paediatric oncology patients with diarrhoea (14.4% - 23/160), compared to non-oncology paediatric patients with diarrhoea only (5.1% - 7/137). With the exception of one sample, all microscopy-positive samples (n=29) and an additional 3/30 microscopy-negative controls were typed to species and subtype level at the 18S and gp60 loci, respectively. All Cryptosporidium positives were typed as C. parvum. Of the 22 typed Cryptosporidium positives from the paediatric oncology patients, 21 were subtyped as IIaA17G2R1 and one as IIaA16G2R1 C. parvum subtypes. The 7 typed positives from the paediatric patients from Al-Mafraq hospital were subtyped as IIaA17G2R1 (n=5) and IIaA16G2R1 (n=2). The 3 additional positives from the 30 microscopy negative control samples were subtyped as IIaA17G2R1. The high prevalence of the IIaA17G2R1 subtype, particularly amongst oncology patients, suggests that an outbreak of cryptosporidiosis may have been occurring in oncology patients during the collection period (April to December, 2016). New therapies for cryptosporidiosis in immunocompromised patients are urgently required.

Longitudinal monitoring of Cryptosporidium species in pre-weaned dairy calves on five farms in Shanghai, China

In pre-weaned dairy calves, the zoonotic and pathogenic species Cryptosporidium parvum is the dominant Cryptosporidium species in most industrialized nations. In several studies in China, however, C. bovis has been the dominant one. To further examine the distribution of Cryptosporidium species in pre-weaned dairy calves in China, 818 fecal specimens were collected from five farms in Shanghai, with repeated samplings (up to five times) on each farm. PCR-restriction fragment length polymorphism (RFLP) analysis of the small subunit rRNA gene was used to detect and genotype Cryptosporidium spp. Cryptosporidium parvum was subtyped by sequence analysis of the 60kDa glycoprotein gene. Cryptosporidium occurrence on farms varied between 25.0% (Farm 2) and 55.0% (Farm 4), with a mean infection rate of 37.0%. Three Cryptosporidium species were detected, including C. bovis (193/303 or 63.7%), C. parvum (72/303 or 23.8%) and C. ryanae (32/303 or 10.6%). Concurrent infection of C. bovis and C. ryanae was detected in six (1.9%) animals. During the first two samplings, C. bovis was the dominant species on four farms and C. parvum was detected on only one farm (Farm 1). One of the study farms (Farm 3) started to have C. parvum at the third sampling. C. parvum was associated with the occurrence of moderate or watery diarrhea, while C. bovis was not. All C. parvum were subtype IIdA19G1, which is dominant in China but rare elsewhere. Genotyping and subtyping results indicated that the introduction of C. parvum to Farm 3 was caused by brief housing of several bull calves from another farm. Data from the study suggest that C. parvum is still uncommon in pre-weaned dairy calves in China and measures should be developed to prevent its spread in the country.

Molecular characterization of cryptosporidium in children aged 0- 5 years with diarrhea in Jos, Nigeria

Introduction

Cryptosporidium is an important cause of diarrhea in children and immune-compromised individuals. Recent advances in molecular diagnostics have led to the discovery of subtype families that are thought to be more commonly associated with diarrhea. We aimed to isolate and characterize Cryptosporidium spp among children with diarrhea in Jos, Nigeria.

Methods

Stool samples were collected from165 children aged 0-5 years with diarrhea. Cryptosporidium oocysts were examined by wet mount preparation, using formalin ether and a modified acid fast staining method. DNA was extracted from positive samples using QIAamp DNA stool mini kit and PCR-RFLP assay was carried out after quantification. Genotyping and phylogenetic analysis were done to determine the subtype families and their relatedness.

Results

From the 165 children studied, 8 (4.8%) were infected with Cryptosporidium. PCR-RFLP assay and genotype characterization found the following Cryptosporidium species: C. hominis 6 (75%) and C. parvum 2 (25.0%), with family subtypes Id-5, Ie-1 and IIa-1, IId-1 respectively.The most common species was C. hominis and the frequent subtype was C. hominis-Id 5 (62.5%).

Conclusion

Cryptosporidium is not an uncommon cause of diarrhea in children, with C. hominis being the dominant species. Also C. hominis Id is the commonest sub-family subtype. Put together, zoonotic species may be an important cause of diarrhea in children aged 0-5 years in Jos, Nigeria.

Multilocus typing of Cryptosporidium spp. in young calves with diarrhea in Korea

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Cryptosporidium spp. were detected using PCR and ELISA in diarrheal feces from calves.

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PCR and ELISA data showed good agreement in detecting C. parvum.

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Multilocus typing with 18S rRNA, gp60, and hsp70 genes of C. parvum was performed.

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Subtyping of C. parvum gp60 gene first revealed IIaA18G3R1 and IIaA16G3R1 in Asia.

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PCR and sequencing of hsp70 gene clearly differentiated C. bovis and C. ryanae.

We assessed the prevalence and performed molecular analysis of Cryptosporidium spp. in diarrheal feces of calves in Korea. Diarrheal fecal samples were collected from 951 young calves (<3 months) on 425 farms. Cryptosporidium prevalence was assessed by PCR and ELISA, and molecular characterization was performed by targeting the 18S rRNA, heat-shock protein 70 (hsp70), and glycoprotein 60 (gp60) genes. Data were analyzed according to the sex, type of cattle, region, season, and type of diarrhea. PCR analysis revealed Cryptosporidium spp. in 9.9% (94/951) of diarrheal fecal samples. C. parvum and C. bovis/ryanae were present in 6.1% (58/951) and 4.1% (39/951) of diarrheal fecal samples, respectively. In addition, ELISA showed positive results for C. parvum in 9.7% (92/951) samples. Statistical analysis of the PCR and ELISA results revealed a lower prevalence of C. parvum in the hemorrhagic diarrheal samples (P < 0.05). For C. bovis/ryanae, seasonality and high prevalence in hemorrhagic diarrhea were observed (P < 0.05). Of the 951 samples tested for C. parvum, 903 samples showed agreement with a κ value of 0.65, indicating good agreement between the two tests. Although C. bovis and C. ryanae share highly similar 18S rRNA sequences, PCR based on hsp70 successfully distinguished C. bovis from C. ryanae. Sequence analysis of gp60 revealed that C. parvum belonged to the IIa families and was further subtyped as IIaA18G3R1 and IIaA16G3R1, which have not been previously reported in Asia. These findings indicate that Cryptosporidium spp. play an important role in diarrhea in young calves in Korea. Considering the zoonotic significance of C. parvum IIa subtype and dense rearing system of cattle in Korea, prevention and continuous monitoring of Cryptosporidium are required.

Evolving epidemiology of reported cryptosporidiosis cases in the United States, 1995-2012

Cryptosporidium is the leading aetiology of waterborne disease outbreaks in the United States. This report briefly describes the temporal and geographical distribution of US cryptosporidiosis cases and presents analyses of cryptosporidiosis case data reported in the United States for 1995-2012. The Cochran-Armitage test was used to assess changes in the proportions of cases by case status (confirmed vs. non-confirmed), sex, race, and ethnicity over the study period. Negative binomial regression models were used to estimate rate ratios (RR) and 95% confidence intervals (CI) for comparing rates across three time periods (1995-2004, 2005-2008, 2009-2012). The proportion of confirmed cases significantly decreased (P < 0·0001), and a crossover from male to female predominance in case-patients occurred (P < 0·0001). Overall, compared to 1995-2004, rates were higher in 2005-2008 (RR 2·92, 95% CI 2·08-4·09) and 2009-2012 (RR 2·66, 95% CI 1·90-3·73). However, rate changes from 2005-2008 to 2009-2012 varied by age group (P interaction < 0·0001): 0-14 years (RR 0·55, 95% CI 0·42-0·71), 15-44 years (RR 0·99, 95% CI 0·82-1·19), 45-64 years (RR 1·47, 95% CI 1·21-1·79) and ⩾65 years (RR 2·18, 95% CI 1·46-3·25). The evolving epidemiology of cryptosporidiosis necessitates further identification of risk factors in population subgroups. Adding systematic molecular typing of Cryptosporidium specimens to US national cryptosporidiosis surveillance would help further identify risk factors and markedly expand understanding of cryptosporidiosis epidemiology in the United States.

Cryptosporidium parvum and Enterocytozoon bieneusi in American Mustangs and Chincoteague ponies

The prevalence of Cryptosporidium and microsporidia in feral horses, which have minimal contact with livestock and humans, is not currently known. We report the findings of a study on Cryptosporidium and microsporidia in 34 Mustangs and 50 Chincoteague ponies in the USA. Fecal samples were screened for presence of Cryptosporidium spp. by analysis of the small-subunit rRNA (SSU) and 60-kDa glycoprotein (gp60) genes, and Enterocytozoon bieneusi and Encephalitozoon spp. by analysis of the ribosomal internal transcribed spacer region (ITS). Cryptosporidium spp. and E. bieneusi were detected in 28/84 (33.3%) and 7/84 (8.3%) samples, respectively. Sequence analysis of SSU and ITS revealed the presence of Cryptosporidium parvum (n = 20) and E. bieneusi genotype horse 1 (n = 7), respectively. Subtyping of C. parvum isolates at the gp60 locus showed the presence of subtype IIaA17G2R1 in Mustangs and subtypes IIaA13G2R1 and IIaA15G2R1 in Chincoteague ponies. Enterocytozoon bieneusi genotype horse 1 was detected in Mustangs (n = 2) and Chincoteague ponies (n = 5). No Cryptosporidium or E. bieneusi positive animals had diarrhea. The finding that Mustangs and Chincoteague ponies are host to the zoonotic pathogen C. parvum suggests that their infrequent contact with humans and livestock is sufficient to maintain transmission; however, we should also consider the possibility that C. parvum is an established parasite of Mustangs and Chincoteague ponies that persists in these animals independently of contact with humans or livestock.

Molecular characterization and first report of Cryptosporidium genotypes in human population in the Slovak Republic

In our study, we examined 91 fecal samples from five different groups of people containing HIV patients, hemodialysis patients, kidney transplant recipients, immunocompetent humans without clinical signs, and humans with suspected cryptosporidiosis. The purpose of our study was to determine species and genotype composition of representatives of Cryptosporidium spp. using PCR analysis of small subunit ribosomal RNA gene and 60-kDa glycoprotein gene and examine their phylogenetic relationship. In HIV-positive/AIDS-infected group of patients and in hemodialysis patients, no presence of Cryptosporidium species was detected. In two kidney transplant recipients, we detected species/genotypes Cryptosporidium parvum IIaA13G1T1R1 (KT355488) and Cryptosporidium hominis IaA11G2R8 (KT355489) and in two immunocompetent patients with clinical symptoms, we identified Cryptosporidium muris and C. hominis IbA10G2T1 (KT355490). In the group of healthy immunocompetent individuals without clinical signs, we identified species/genotype C. hominis IbA11G2 (KT355491) in one sample.

First genetic identification of Cryptosporidium parvum subtype IIaA14G2R1in beef cattle in Brazil

The presence of Cryptosporidium spp. in a cattle herd registered with an outbreak of diarrhea was investigated and the the molecular subtyping of Cryptosporidium parvum was characterized. Fecal samples from 85 Nellore beef cattle (Bos indicus) were collected and examined with Ziehl-Neelsen modified staining method. Fifty-four cattle (63.52%) had Cryptosporidium spp. oocysts in their feces. Fragments of genes encoding the 18S ribosomal RNA subunit and a 60-kDa glycoprotein (gp60) were amplified by nested PCR accomplished in the 11 most heavily parasitized samples, and the amplicons were sequenced. Eight of the 11 analyzed samples were positive for 18S rRNA sequences and identified monospecific infections with C. parvum. Seven samples were positive for gp60 and identified subtypes IIaA15G2R1 (6/11) and IIaA14G2R1 (1/11). This report is the first for C. parvum subtype IIaA14G2R1 in beef cattle in Brazil.

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in diarrhoeic patients in the Qikiqtani Region, Nunavut, Canada

Background

Although the prevalences of infection with the protozoan parasites Cryptosporidium spp. and Giardia duodenalis in humans appear to be relatively high in the Canadian North, their transmission patterns are poorly understood.

Objective

To determine the detection rate and the molecular characteristics of Cryptosporidium spp. and Giardia duodenalis in diarrhoeic patients in the Qikiqtani (Baffin Island) Region of Nunavut, Canada, in order to better understand the burden of illness and the potential mechanisms of transmission.

Study design/methods

Diarrhoeal stool specimens (n=108) submitted to the Qikiqtani General Hospital for clinical testing were also tested for the presence of Cryptosporidium spp. and Giardia duodenalis using epifluorescence microscopy and polymerase chain reaction (PCR). DNA sequencing and restriction fragment length polymorphism (RFLP) analyses were performed on PCR-positive specimens to determine the species, genotypes and sub-genotypes of the parasites.

Results

Cryptosporidium was detected in 15.7% of the diarrhoeic patients, while Giardia was detected in 4.6%. DNA sequencing of a fragment of the small subunit rRNA gene indicated that all of the Cryptosporidium amplicons had a 100% homology to C. parvum, and a gp60 assay showed that all aligned with C. parvum sub-genotype IIa. Microsatellite analysis revealed 3 cases of sub-genotype IIaA15G2R1, 2 of IIaA15G1R and 1 case each of sub-genotypes IIaA16G1R1 and IIaA15R1. For Giardia, results based on the amplification of both the 16S rRNA gene and the gdh gene were generally in agreement, and both DNA sequencing and RFLP demonstrated the presence of the G. duodenalis Assemblage B genotype.

Conclusions

Both C. parvum and G. duodenalis Assemblage B were present in human diarrhoeal stool specimens from Nunavut, which was suggestive of zoonotic transmission, although human-to-human transmission cannot be ruled out. To fully understand the public health significance of the different Cryptosporidium and Giardia species and genotypes in diarrhoeic patients, it will be imperative to establish the extent of genetic diversity within these parasites through comprehensive studies of the molecular epidemiology of cryptosporidiosis and giardiasis in the Nunavut region.

Molecular characterization of Cryptosporidium parvum from two different Japanese prefectures, Okinawa and Hokkaido

Infectious diarrhea is the most frequent cause of morbidity and mortality in neonatal calves. Cryptosporidium parvum is one of the main pathogens associated with calf diarrhea. Although diarrhea is a symptom of infection with various pathogens, investigations to detect the types of pathogens have never been performed in Japan. This study investigated the prevalence of four major diarrhea-causing pathogens in calves: C. parvum, rotavirus, coronavirus, and enterotoxigenic Escherichia coli (E. coli K99). Commercial immunochromatography testing of all four pathogens and molecular analysis of C. parvum with diarrhea in calves from southernmost Okinawa and northernmost Hokkaido, Japan, were conducted. The frequencies of C. parvum, rotavirus, coronavirus, and E. coli (K99) in Okinawa were 50%, 28%, 2.3%, and 4.7%, respectively. Watery fecal stools were significantly correlated with C. parvum (p < 0.05). In oocyst calculations for C. parvum, no significant difference was observed between the single-infection cases and the mixed-infection cases with rotavirus. Interestingly, molecular analyses targeting small subunit ribosomal RNA as well as glycoprotein 60 (GP60) genes revealed that the C. parvum nucleotide sequences from the two prefectures were identical, indicating that C. parvum with a uniform characteristic is distributed throughout Japan. GP60 subtyping analysis identified C. parvum from Okinawa and Hokkaido as belonging to the IIaA15G2R1 subtype, a known zoonotic subtype. Hence, control of cryptosporidiosis is important not only for pre-weaned calves, but also for human health.

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ICT strips were used for calf diarrhea to detect four major enteric pathogens.

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C. parvum showed the highest frequency in the southernmost Okinawa prefecture, Japan.

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C. parvum from the northernmost Hokkaido prefecture was used for a comparative study.

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C. parvum from the two prefectures had a uniform character in SSUrRNA and GP60 genes.

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GP60 subtyping revealed that IIaA15G2R1, a known zoonotic subtype, was predominant.

Evaluation of a protocol to reduce the incidence of neonatal calf diarrhoea on dairy herds

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Dams were vaccinated against E. coli, rota and corona, calves received halofuginone.

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The average % of neonatal calf diarrhoea was significantly lower on trial herds.

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The average shedding of C. parvum was significantly lower on trial herds.

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No significant differences were observed in the shedding of E. coli, rota and corona.

Calf diarrhoea causes substantial economic losses in cattle herds worldwide. Neonatal calves are particularly sensitive to infections with enteropathogens. The present study focused on prevention against the main infectious causes of neonatal calf diarrhoea i.e. Escherichia coli, rota- and coronavirus, and Cryptosporidium parvum. Dairy herds (n = 24) with a high percentage of neonatal calves scouring (>10%) were included and calves were sampled for the presence of these four enteropathogens. To decrease diarrhoea problems among neonatal calves, a standard protocol was tested on 13 herds (treatment group) where both C. parvum and either E. coli or rota- or coronavirus were identified as being involved, the other 11 herds served as control group. The protocol consisted of 2 points of action: preventive vaccination of dams against E. coli, rota- and coronavirus, and preventive administration of halofuginone lactate to newborn calves. The average percentage of calves suffering from neonatal diarrhoea (39.7% versus 14.3%, P < 0.01) and the average percentage of faecal samples positive for C. parvum (34% versus 11%, P < 0.05) differed significantly between control herds and treatment herds after implementation of the protocol. No significant differences between control and treatment group were observed in the percentage of calves excreting E. coli, rotavirus and coronavirus, both before and at the end of the trial. Furthermore, risk factors potentially associated with the development of neonatal calf scours were determined. Non-significant results were obtained for the effect of the protocol on duration of diarrhoea and the effect of the colostral IgG quantity on the risk of diarrhoea. Passive immunity transfer status of the calves, measured both before the onset and at the end of the study, were non-significant between groups.

Molecular characterization ofCryptosporidium parvumisolates from human cryptosporidiosis cases in Scotland

Cryptosporidium parvum(C. parvum) is one of the most prevalent protozoan pathogens responsible for inducing human and animal disease worldwide. In this study, the glycoprotein-60 (gp60) subtyping tool was employed to assess the molecular diversity ofC. parvumfrom human feces throughout Scotland during potential outbreaks. Over a 24-month period, microscopy analysis revealed 1139 positive feces containingCryptosporidiumspecies with 256 identified by molecular methods specifically asC. parvum. Cryptosporidium parvumwas shown to be more prevalent in rural areas of Scotland and subtyping of 87 isolates demonstrated the predominant family as IIa, which occurred in 94% (n = 82) of isolates. The IIaA15G1R1 subtype was most common, being isolated from 47% (n = 41) of Scottish human cases. Non-IIa strains constituted a total of 5 isolates and included subtypes from the IIc, IId and IIg families. This information contributes significantly to existing knowledge and understanding ofC. parvumsubtypes in Scotland which is vital in assisting with the management of future local and national outbreaks.

Prevalence and molecular typing of Cryptosporidium in dairy cattle in England and Wales and examination of potential on-farm transmission routes

An average of 70 samples were collected from 80 dairy farms in England and Wales, from cattle, co-grazed sheep, wildlife and farm wastes, to investigate prevalence, potential sources and transmission routes of Cryptosporidium. At least one positive sample was detected on 74 of the farms (92.5%) by IFAT microscopy. The prevalence in cattle was 10.2% (95% CI 9.4-11.1%), with greater prevalences detected in calf samples, especially from those under 1 month (45.1%). Young calves were also more likely to be shedding Cryptosporidium parvum and larger concentrations of oocysts, whereas older calves and adult cattle were more likely to be shedding Cryptosporidium bovis and Cryptosporidium andersoni, respectively. The C. parvum subtypes detected were predominantly from types commonly identified in UK cattle (67% were either IIaA15G2R1 or IIaA17G1R1). A novel subtype, IIaA17G1R2, was identified from one cattle sample. The prevalence in co-grazed sheep was low (4%). Birds and rodents may represent significant reservoirs of Cryptosporidium due to high prevalence, large oocyst concentrations, and the detection of a C. parvum subtype known to be present in human populations, identified in samples from these wildlife. Cryptosporidium were detected in dirty water and manure, and also from pasture samples where slurry had been spread. On 64% of the farms, identical Cryptosporidium species were detected (mainly C. parvum or C. bovis) from different cattle groups on the farms, although no direct or indirect contact between the groups were recorded, apart from sharing staff. The same Cryptosporidium species were found in cattle, farm wastes and bird samples on the same farms, but rarely, or not at all, present in sheep or rodent samples. The matching of species/subtypes was also related to the proximity of the different sample sources which may indicate a potential transmission route.

Molecular Characterization of Cryptosporidium spp. Isolated From Immunocompromised Patients and Children

BACKGROUND

Cryptosporidium is known to be one of the most important causes of diarrhea in children and immunocompromised patients. Genotype characterization of Cryptosporidium species in each region would help in the treatment of this disease, as well as to locate the source of infection and to prevent the disease.

OBJECTIVES

This current research was conducted in order to analyze the molecular characterization of isolated Cryptosporidium spp. in the Southwest of Iran.

MATERIALS AND METHODS

In this survey, 390 fecal samples were collected from immunocompromised individuals and children under five-years-of-age. Parasitic infection was evaluated using wet mount preparation, formalin ether, a modified acid fast staining method and microscopic examination. Finally, a PCR-RFLP assay was performed on the extracted DNA collected from fecal samples that were positive for Cryptosporidium by the acid fast method.

RESULTS

Among the 390 fecal samples, 16 cases (4.1%) were infected with Cryptosporidium. Molecular and genotype characterization found the following protozoan species; 11 Cryptosporidium parvum (68.8%), 4 C. hominis (25%), and one case of C. meleagridis (6.2%).

CONCLUSIONS

The present study emphasized the public health importance of Cryptosporidium spp. in the study area. In addition, it seems that zoonotic species are the most important causes of infection in the region. As far as we are aware this the first report of a C. meleagridis infection in Iran.

New Cryptosporidium parvum subtypes of IIa subfamily in dairy calves from Brazil

Bovine cryptosporidiosis is mainly caused by four distinct species: Cryptosporidium parvum, C. bovis, C. ryanae and C. andersoni. The first, C. parvum, is a major concern in livestock causing economic losses, in addition to public health impact because of its zoonotic characteristics. The present study aimed to determine the occurrence of different species and subtypes of Cryptosporidium using molecular techniques. A total of 143 fecal samples were collected from calves from three dairy farms located in the state of Rio de Janeiro, Brazil. Saturated sugar centrifugal flotation method was used for the microscopic evaluation of the samples. Among these samples, 19.6% (28) were positive by microscopy, and 82.1% (23) of these 28 samples had their diagnosis confirmed by PCR using 18S as gene target. After sequencing, three species of Cryptosporidium were found to infect calves in different age groups. In pre-weaning phase (<2 months), 10% (3/30) of the calves were infected with C. parvum, whereas 14.2% (16/113) of post-weaning calves (≥2 months) were observed to be infected with C. andersoni and 1.8% (2/113) by C. ryanae with the latter diagnosed for the first time in the state of Rio de Janeiro. Those samples identified as C. parvum were further characterized at the GP60 locus, and PCR products were cloned. Eight different subtypes (IIaA20G2R1, IIaA20G2R2, IIaA19G2R1, IIaA19G2R2, IIaA18G1R1, IIaA18G2R2, IIaA16G3R2 and IIaA14G2R2) of C. parvum were identified, all belonging to the IIa family subtype, which is considered of high zoonotic potential. The subtypes mentioned above have not yet been detected in Brazilian cattle, and four of these subtypes (IIaA20G2R2, IIaA19G2R2, IIaA18G2R2 and IIaA14G2R2) had not been diagnosed elsewhere in calves until this study.

Cryptosporidium parvum GP60 subtypes in dairy cattle from Buenos Aires, Argentina

Cryptosporidium parvum from 73 dairy calves less than two months old from Buenos Aires province (Argentina) were molecularly characterized using sequence analysis of the GP60 gene. Seventy-five sequences were obtained, and seven different subtypes were identified, all belonging to the IIa subtype family. The most common subtypes were IIaA20G1R1 (27/75), IIaA22G1R1 (16/75), and IIaA18G1R1 (13/75). Subtypes IIaA21G1R1, IIaA23G1R1, IIaA16G1R1 and IIaA19G1R1 were found sporadically. Two samples contained mixed infections with IIaA21G1R1 and IIaA22G1R1. A significant association was found between subtypes and geographic location, whereas there was no relation between subtypes and presence of diarrhea. Three of the subtypes found in this study (IIaA16G1R1, IIaA18G1R1, and IIaA19G1R1) were previously identified in humans. These findings suggest that cattle could play an important role in the transmission of cryptosporidiosis to humans in Buenos Aires province.

Glycoprotein 60 diversity in Cryptosporidium parvum causing human and cattle cryptosporidiosis in the rural region of Northern Tunisia

The zoonotic potential of Cryptosporidium parvum was studied in an extensive cattle farming region of northern Tunisia. Seventy fecal samples from pre-weaning calves and 403 fecal samples from children were examined by microscopy after modified Ziehl-Neelsen (MZN) staining. Positive Cryptosporidium specimens were identified at a species level using an 18S rRNA nested polymerase chain reaction (PCR) followed by an Restriction Fragment Length Polymorphism (RFLP) analysis. C. parvum isolates were subgenotyped by sequence analysis of the glycoprotein 60 (gp60) gene. Among calf samples, 14 samples were positive by MZN method. C. parvum was identified in all cases. Twelve parvum isolates (85.7%) belonged to family subtype IIa. Subtype IIaA15G2R1 was more prevalent (50%). Two C. parvum isolates corresponded to the IIdA16G1 subtype. Seven human samples were positive by MZN method. C. parvum and C. meleagridis were identified in four and three cases, respectively. Intraspecific characterization of C. parvum identified two subtypes, the IIaA15G2R1 and the IIdA16G1, also found in calves.

Prevalence and genetic characterization of Cryptosporidium in yaks in Qinghai Province of China

The objective of this study was to determine the prevalence, species and subtypes of Cryptosporidium infecting yaks in the Qinghai Province of Northwestern China. The prevalence of Cryptosporidium spp. was detected by microscopy and nested-PCR. A total of 586 fecal samples were collected from yaks in 6 counties, of which 142 (24.2%) samples tested positive for Cryptosporidium. The small subunit (SSU) rRNA gene of fifty-five samples were amplified and sequenced successfully and demonstrated that Cryptosporidium bovis (31/55, 56.4%) was the most common species, followed by C. parvum (16/55, 29.1%) and C. ryanae (5/55, 9.0%). Mixed infections of C. parvum and C. bovis (n = 2), C. ryanae and C. bovis (n = 1) were also detected. All three species were found in yaks ranging in age from <1 year, 1–2 years, to >2 years. Cryptosporidium was most commonly detected in spring (28.4%), followed by summer (20.9%), then winter (17.5%). Cryptosporidium parvum positive samples were subtyped using the 60 kDa glycoprotein (gp60) gene. Subtypes IIaA15G2R1 (n = 8), IIaA16G2R1 (n = 2), IIaA14G1R1 (n = 1), IIaA14G2R1 (n = 1) and IIaA16G3R1 (n = 1) were detected. All of these subtypes are zoonotic, and may pose a potential threat to human health.

Is there a need for improved Cryptosporidium diagnostics in Swedish calves?

Cryptosporidium parvum is a common pathogen in preweaned calves but in Sweden Cryptosporidium bovis, which is considered apathogenic, is the most common species in this age group and it has been identified in diarrhoeal samples, indicating that it could be a cause of diarrhoea. In routine diagnostic procedures, infection is determined by microscopy, which is not sufficient to differentiate these species. We investigated whether routine Cryptosporidium diagnostic procedures need improvement to include species determination. The relation of Cryptosporidium spp. and subtype with the clinical picture and other pathogens was also investigated. A total of 782 diarrhoeal calf samples were analysed and Cryptosporidium infection was diagnosed in 198 samples. Cryptosporidium parvum was identified in 178, C. bovis in six and mixed C. bovis/C. parvum in seven samples. Twenty-seven C. parvum subtypes were identified, of which 16 were newly described. Except for three herds, only one subtype per herd was identified. Cryptosporidium parvum-positive calves were younger than C. bovis-positive calves and most C. parvum infections were seen at 1-3 weeks of age. Oocyst counts were higher in C. parvum samples. Yellow faecal colour was associated with C. parvum infection. Watery faeces had no greater association with C. parvum infection, but C. parvum subtype family IIa was more common than subtype family IId in watery faecal samples. No other pathogens were detected in the six C. bovis-infected calves, indicating a pathogenic potential. Our results show that species determination does not need to be included in routine Cryptosporidium diagnostic procedures in order to estimate the clinical relevance of infection in diarrhoeal calves. The maximum age when analysis for clinical cryptosporidiosis is performed can be lowered to 6 weeks of age. However, the indicated pathogenic potential of C. bovis warrants further attention.

Distribution and genetic characterizations of Cryptosporidium spp. in pre-weaned dairy calves in Northeastern China's Heilongjiang Province

Background

Cryptosporidium spp. are common parasites of humans and animals. Farm animals, especially pre-weaned calves, are considered to be one of main animal reservoir hosts of Cryptosporidium in the transmission of human cryptosporidiosis. The aim of this study was to determine the distribution and genotypes of Cryptosporidium spp. in pre-weaned calves using molecular tools and to assess zoonotic transmission and elucidate the public health significance in northeastern China.

Methodology/Principal Findings

A total of 151 fecal specimens from pre-weaned calves were collected in Heilongjiang Province and were screened for Cryptosporidium by PCR. The average prevalence of Cryptosporidium was 47.68% (72/151). Cryptosporidium spp. were characterized by DNA sequencing of the small subunit (SSU) rRNA gene and the 60-kDa glycoprotein (gp60) gene. Based on the SSU rRNA gene, five Cryptosporidium spp. were identified, including C. bovis (n = 34), C. andersoni (n = 26), C. ryanae (n = 5), C. meleagridis (n = 5) and C. parvum (n = 2). The SSU rRNA nucleotide sequences were identical to each other, respectively, within C. ryanae, C. parvum, C. meleagridis and C. andersoni. Four types of C. bovis were found in the SSU rRNA gene, with two novel types. The gp60 gene was successfully sequenced in one C. parvum isolate and three C. meleagridis isolates, with IIdA19G1 for C. parvum and IIIeA22G2R1 for C. meleagridis.

Conclusion/Significance

Molecular analysis indicates that Cryptosporidium spp. are endemic in pre-weaned calves in Heilongjiang Province. The findings of C. parvum and C. meleagridis suggested the possibility of zoonotic transmission and public health significance. The transmission dynamics of C. parvum and C. meleagridis needed to be clarified by further molecular epidemiologic studies from humans and animals. Whether calves could act as the natural reservoirs of C. meleagridis needed to be confirmed by more systematic experimental infection studies.

Evidence that Cryptosporidium parvum populations are panmictic and unstructured in the Upper Midwest of the United States

Cryptosporidium parvum is a zoonotic protozoan parasite that causes cryptosporidiosis, an infectious diarrheal disease primarily affecting humans and neonatal ruminants. Understanding the transmission dynamics of C. parvum, particularly the specific contributions of zoonotic and anthroponotic transmission, is critical to the control of this pathogen. This study used a population genetics approach to better understand the transmission of C. parvum in the Upper Midwest United States. A total of 254 C. parvum isolates from cases of human cryptosporidiosis in Minnesota and Wisconsin and diarrheic calves in Minnesota, Wisconsin, and North Dakota were genotyped at eight polymorphic loci. Isolates with a complete profile from all eight loci (n = 212) were used to derive a multilocus genotype (MLT), which was used in population genetic analyses. Among the 94 MLTs identified, 60 were represented by a single isolate. Approximately 20% of isolates belonged to MLT 2, a group that included both human and cattle isolates. Population analyses revealed a predominantly panmictic population with no apparent geographic or host substructuring.

Genetic characterisation of Cryptosporidium and Giardia from dairy calves: discovery of species/genotypes consistent with those found in humans

Cryptosporidium and Giardia are important genera of parasitic protists that can cause significant diarrhoeal diseases in humans and other animals. Depending on the species/genotype of parasite, human infection may be acquired via anthroponotic or zoonotic transmission routes. Here, we undertook a molecular epidemiological investigation of these two genera of parasites in pre- and post-weaned calves from eight locations in Canterbury, New Zealand, by PCR-coupled sequencing and phylogenetic analysis of sequence data for regions in the 60 kDa glycoprotein (pgp60) gene of Cryptosporidium and/or the triose-phosphate isomerase (ptpi) gene of Giardia. The pgp60 and ptpi regions were specifically amplified from 15 (8.3%) and 11 (6.1%) of the 180 individual faecal samples, respectively. The sequences derived from all of the amplicons were aligned with homologous reference sequences and subjected to phylogenetic analysis by Bayesian inference. For Cryptosporidium, three samples contained Cryptosporidium parvum genotype IIa, subgenotypes IIaA15G3R1, IIaA19G3R1 and IIaA23G4. Twelve samples contained Cryptosporidium hominis genotype Ib, subgenotype IbA10G2R2. While subgenotypes IIaA15G3R1 and IIaA23G4 are new records, IIaA19G3R1 and IbA10G2R2 are commonly found in humans in various countries. For Giardia, two samples contained Giardia duodenalis assemblage A, also common in humans. In contrast, nine samples contained G. duodenalis assemblage E, which is the first report of this assemblage in cattle in New Zealand. Therefore, the present results indicate that dairy calves on the South Island of New Zealand harbour 'zoonotic' genotypes of Cryptosporidium and Giardia, which is likely to have significant public health implications.

Cryptosporidium species in Australian wildlife and domestic animals

Cryptosporidium is an important enteric parasite that is transmitted via the fecal-oral route, water and food. Humans, wildlife and domestic livestock all potentially contribute Cryptosporidium to surface waters. Most species of Cryptosporidium are morphologically indistinguishable and can only be identified using molecular tools. Over 24 species have been identified and of these, 7 Cryptosporidium species/genotypes are responsible for most human cryptosporidiosis cases. In Australia, relatively few genotyping studies have been conducted. Six Cryptosporidium species (C. hominis, C. parvum, C. meleagridis, C. fayeri, C. andersoni and C. bovis) have been identified in humans in Australia. However, little is known about the contribution of animal hosts to human pathogenic strains of Cryptosporidium in drinking water catchments. In this review, we focus on the available genotyping data for native, feral and domestic animals inhabiting drinking water catchments in Australia to provide an improved understanding of the public health implications and to identify key research gaps.

Experimental infection with Cryptosporidium parvum IIaA21G1R1 subtype in immunosuppressed mice

Cryptosporidium parvum subtype IIaA21G1R1 oocysts were used to infect dexamethasone immunosuppressed N: NIH Swiss mice. This is the first Cryptosporidium mouse model in which the relationship between infection and apoptosis has been histologically studied at each portion of the gut in order to observe this dynamic in chronic cryptosporidiosis. Histology showed developmental stages in the duodenum, proximal and distal jejunum, ileum, cecum and colon, with the small intestine remaining infected until day 35 post infection. At proximal jejunum an inverse correlation between infection and apoptosis was observed at days 28 and 35 p.i. Data suggests that jejunum could be an interesting place to carry out further studies on the dynamics of Cryptosporidium infection and apoptosis. Based on these findings, this mouse model was useful to evaluate clinical, parasitological and histological aspects of C. parvum subtype IIaA21G1R1 infection, and it will be an appropriate tool to investigate different aspects of Cryptosporidium infection.