Prevalence of Cryptosporidium parvum infection and pattern of oocyst shedding in calves in Japan

Recombinant Cryptosporidium parvum GP15 based enzyme linked immunosorbent assay for detection of exposure of bovine populations to Cryptosporidium

The serodiagnostic potential of recombinant Cryptosporidium parvum glycoprotein 15 (rCpGP15) was evaluated in Enzyme Linked Immunosorbent Assay (ELISA) in the detection of exposure of bovines to Cryptosporidium species in Himachal Pradesh and Uttarakhand states of North India. The 11.13 kDa rCpGP15 was expressed in pET-32a (+) transformed E. coli BL21 cells and was purified by Ni-NTA affinity chromatography as polyhistidine tagged fusion protein of ∼ 32 kDa. Its immunogenicity was checked in western blot using rabbit antisera raised to the recombinant antigen and bovine sera naturally infected with Cryptosporidium. Two hundred and forty-six bovines were screened for Cryptosporidium spp. oocysts in faecal samples by modified-Ziehl Neelson technique and their sera were used for ELISA standardization. The rCpGP15 based indirect IgG-ELISA was standardized with 83 % sensitivity, 78.3 % specificity where ELISA cut-off and accuracy were decided using ROC curve analysis. The percent accuracy was 79.19 %, with area under the Receiver Operating Characteristic (ROC) curve value 0.827 depicting the moderate accuracy of the assay. Additionally, sera from Eimeria (n = 3), strongyles (n = 3), Babesia (n = 2), Theileria (n = 5), Trypanosoma (n = 2) and Anaplasma (n = 5) positive animals showed no seroreactivity. The diagnostic performance of rCpGP15 protein in differentiating Cryptosporidium species was predicted through in-silico B cell epitope prediction, homology modelling and structural comparison of GP15 protein from C. parvum, C. hominis, C. bovis and C. ryanae. Four linear antigenic epitopes were predicted in CpGP15 protein sequence by SVMTrip. The overall root mean square deviation (RMSD) values during homology modelling and structural comparison of CpGP15 and C. hominis, C. bovis and partial C. ryanae GP15 were 2.093 Å, 3.759 Å and 1.152 Å, respectively. The serodiagnostic assay developed in the present study has moderate accuracy and can be applied in serosurveillance of large bovine populations. It is capable of detecting asymptomatic animals with intermittent oocyst shedding which will further be helpful for better understanding the disease dynamics and for the timely control of cryptosporidiosis.

Comprehensive molecular epidemiology of Cryptosporidium species in Japan

Cryptosporidium species, causing diarrheal illnesses in humans and animals worldwide, are under investigation for their molecular epidemiology in Japan. The study focuses on detecting Cryptosporidium species in humans, animals, water, and the environment, revealing three species in people: C. parvum, C. meleagridis, and C. hominis. Subtype IIa of the C. parvum gp60 gene is prevalent, indicating potential zoonotic transmission. Animal studies identified sixteen species, mainly cattle and pets, with C. parvum (subtype IIa) common in cattle and C. canis and C. felis prevalent in pets. Additionally, C. bovis and C. ryanae were found in cattle and sika deer. Knowledge gaps exist, particularly in water and environmental source typing, with limited research revealing five species and five genotypes, suggesting a significant role of water in transmission. Further research is needed to understand the molecular diversity and transmission dynamics across humans, animals, water, and the environment in Japan.

Population genetics of Cryptosporidium parvum subtypes in cattle in Poland: the geographical change of strain prevalence and circulation over time

Background

Cryptosporidium parvum (C. parvum) is a cosmopolitan parasite that infects various livestock animals including cattle. Microsatellite typing tools for identification of C. parvum subtypes are currently employed to better understand the species-specific epidemiology of cattle cryptosporidiosis. The aim of this study was to analyse the population genetics of C. parvum strains infecting cattle and recognise geographical distribution and time-span correlations in subtype prevalence in Poland. In total, 1601 faecal samples were collected from 2014 to 2018 from healthy cattle from dairy, meat and mixed breeds at the age of 1 week to 4 months. The 267 farms visited were randomly selected and represented all Polish provinces. PCR–RFLP based identification of C. parvum at the 18 small subunit ribosomal RNA (SSU rRNA) locus was performed, followed by strain subtyping by GP60-PCR. 

Results

The overall prevalence of C. parvum in Polish cattle was estimated at 6.2% (100/1601). Animals below the age of 1 month were the major host for this parasite. Excluding one breed, that of dairy-meat mixed, there were no significant differences observed between breed and presence of C. parvum infections (95% TPI_{All breeds}: 1.67–73.53%; POPR = 0.05—0.95). Infected animals were detected in 15 out of 16 Polish provinces, with significant regional prevalence diffrences (Kruskal–Wallis rank sum test, Kruskal–Wallis χ² = 13.46, p < 0.001). When the population genetics of C. parvum strains were analysed, 11 parasite subtypes from the IIa and IId genetic families were identified. Compared to other parasite strains, IIaA17G1R1 and IIaA17G2R1 appeared at statistically significantly higher frequency (F-test, F = 3.39; p = 0.0003). The prevalence of C. parvum subtypes in cattle was breed-related (Chi-squared test, χ² = 143.6; p < 0.001).

Conclusions

The analysis of the population genetics of C. parvum subtypes showed that strains from the IIa subtype family predominated in the tested cattle population. However, relations in changes of subtype prevalence and circulation over time were observed. They were associated with the disappearance of some strains and emergence of new variants from the same genetic family in different geographical locations.

C. parvum subtypes from the IIa allele family predominated in the tested cattle. The prevalence of C. parvum subtypes in cattle was breed-related. Dynamicity in the population C. parvum strains circulating in cattle was shown.

Genetic diversity of Cryptosporidium species in Njoro Sub County, Nakuru, Kenya

Cryptosporidium spp. cause cryptosporidiosis in humans through zoonotic and anthroponotic transmission. Previous studies illustrated the significance of domestic animals as reservoirs of this parasite. Cryptosporidium occurs in Njoro River; a main source of water to humans and animals. However, there is no information on the Cryptosporidium spp. and genotypes circulating in Njoro Sub County. A total of 2174 samples from humans, cattle, chickens, sheep and goats were assessed for the presence of Cryptosporidium spp. Thirty-three positive samples were subsequently successfully sequenced and compared to Cryptosporidium sequences in the GenBank repository using NCBI's (National Center for Biotechnology Information) online BLAST (Basic Local Alignment Search Tool) algorithmic program. Sequence alignment was done using the Clustal W program and phylogenetic analysis was executed in MEGA X (Molecular Evolutionary Genetics Analysis version X). The prevalence of cryptosporidiosis in Njoro Sub County is 6.99%. Cryptosporidium spp. present in the watershed showed great genetic diversity and nine Cryptosporidium species were recorded: Cryptosporidium parvum, Cryptosporidium hominis, Cryptosporidium ubiquitum, Cryptosporidium meleagridis, Cryptosporidium andersoni, Cryptosporidium baileyi, Cryptosporidium muris, Cryptosporidium xiaoi and Cryptosporidium viatorum. This is the first study to report the presence of C. viatorum in Kenya. Cattle is the major reservoir of zoonotic Cryptosporidium spp. while goats harbored the lowest number of species. Humans and domestic animals drink the contaminated water from Njoro River, humans are therefore, exposed to a high cryptosporidiosis risk.

Phylogenetic characterization of Isospora jaracimrmani oocysts from a veiled chameleon (family Chamaeleonidae; Chamaeleo calyptratus) reared at a zoo in Ishikawa, Japan

Oocysts of Isospora sp. were detected in the feces of a veiled chameleon (family Chamaeleonidae; Chamaeleo calyptratus) kept at a zoo in Ishikawa, Japan. Phylogenetic analysis placed the sequence in the cluster of Isospora spp. isolated from reptiles. Based on a comparison of morphological data of ten previously reported Isospora species from the Chamaeleonidae family, this isolate was morphologically similar to I. jaracimrmani, which has been considered to be a virulent species. This case study suggests the possibility that species of Isospora might not always cause disease because the animal that shed these oocysts showed no symptoms for more than two months.

Genetic diversity and shedding profiles for Cryptosporidium parvum in adult cattle and their calves

Cryptosporidiosis is an important disease in neonatal calves, causing watery diarrhoea, loss of appetite, and production losses. Dehydration from diarrhoea often results in the calf requiring rehydration or veterinary treatment to prevent calf mortality. Transmission of Cryptosporidium to calves still has some major knowledge gaps, such as the initial source of oocysts ingested by calves and how these oocysts can persist between calving periods. Some studies have examined the role of adult cattle in the transmission of Cryptosporidium oocysts, although these have yielded inconclusive results. In this study, highly sensitive oocyst extraction from faeces and detection techniques, sensitive to 5 oocysts per gram using a 50 g sample, were used to genotype faecal samples from adult cattle and their calves to determine if adult cattle could be a source of Cryptosporidium infection for their calves. On a dairy farm, faecal samples from adult cattle were collected twice per week for 0–3 weeks before calving and from their calves three times per week until they reached 3 weeks of age followed by twice per week until they reached 6 weeks of age. On a beef farm, samples were collected from both adults and calves at a single time point. Faecal samples were examined to compare species and multilocus genotypes of Cryptosporidium parvum. Results show that C. parvum was the most prevalent species on both the dairy and beef farms. The calves within each herd appear to have one predominant single multilocus genotype, whereas adult cattle have multiple distinct genotypes. Adult cattle on the dairy farm, tested before calving, in the majority of cases had a multilocus genotype that is different from that detected in their calves. On the beef farm, where samples were taken at the same time, the majority of adult cattle matched the multilocus genotype of their calves. This study shows that adult cattle display a higher diversity of C. parvum genotypes on both farms compared to the calves. The data also represent a detailed longitudinal prevalence study of the shedding profiles and genotype of Cryptosporidium parasites detected in dairy calves from birth to 6 weeks of age.

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On a dairy farm, the majority of adult cattle had a multilocus genotype that was different to those in calves.

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On the beef farm, the majority of adult cattle matched the multilocus genotype of their calves.

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Calves on the dairy farm sampled longitudinally exhibited intermittent shedding of Cryptosporidium oocysts.

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Increased C. parvum genotype diversity was observed in the adult cattle compared to the calves.

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.

Comparative genetic diversity of Cryptosporidium species causing human infections

Parasites sometimes expand their host range and cause new disease aetiologies. Genetic changes can then occur due to host-specific adaptive alterations, particularly when parasites cross between evolutionarily distant hosts. Characterizing genetic variation in Cryptosporidium from humans and other animals may have important implications for understanding disease dynamics and transmission. We analyse sequences from four loci (gp60, HSP-70, COWP and actin) representing multiple Cryptosporidium species reported in humans. We predicted low genetic diversity in species that present unusual human infections due to founder events and bottlenecks. High genetic diversity was observed in isolates from humans of Cryptosporidium meleagridis, Cryptosporidium cuniculus, Cryptosporidium hominis and Cryptosporidium parvum. A deviation of expected values of neutrality using Tajima's D was observed in C. cuniculus and C. meleagridis. The high genetic diversity in C. meleagridis and C. cuniculus did not match our expectations but deviations from neutrality indicate a recent decrease in genetic variability through a population bottleneck after an expansion event. Cryptosporidium hominis was also found with a significant Tajima's D positive value likely caused by recent population expansion of unusual genotypes in humans. These insights indicate that changes in genetic diversity can help us to understand host-parasite adaptation and evolution.

First report of Cryptosporidium spp. infection and risk factors in black-boned goats and black-boned sheep in China

Cryptosporidium is an opportunistic protozoan parasite that can inhabit in the gastrointestinal tract of various hosts. Cryptosporidium infection in black-boned goats and black-boned sheep may pose a threat to the survival and productivity, causing considerable economic losses to the livestock industry. However, it is yet to know whether black-boned goats and black-boned sheep in China are infected with Cryptosporidium. Thus, the objective of the present study was to investigate the prevalence and associated risk factors of Cryptosporidium infection in black-boned goats and black-boned sheep in Yunnan province, China. A total of 590 fecal samples were obtained from black-boned goats and black-boned sheep from five counties in Yunnan province, and the prevalence and species distribution of Cryptosporidium were determined by amplification of the 18S rDNA fragment using the nested PCR. The overall Cryptosporidium prevalence was 13.2% (78/590), with 18.0% (55/305) in black-boned goats and 8.1% (23/285) in black-boned sheep. The age and sampling site were identified as main factors that result in significant differences in Cryptosporidium prevalence. Three species, namely C. muris, C. xiaoi, and C. ubiquitum, were identified in black-boned goats and black-boned sheep in the present study, with C. muris (46/78) as the predominant species. This is the first report of Cryptosporidium infection in black-boned goats and black-boned sheep in China, and the findings will facilitate better understanding, prevention, and control of Cryptosporidium infection in black-boned goats and black-boned sheep in China.

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.

Distribution of Cryptosporidium species isolated from diarrhoeic calves in Japan

Cryptosporidium spp. are enteric protozoan parasites that infect a wide range of hosts including humans, and domestic and wild animals. The aim of this study was to molecularly characterize the Cryptosporidium spp. found in calf faeces in Japan. A total of 80 pre-weaned beef and dairy calves' diarrhoeic faecal specimens were collected from nine different prefectures in Japan. A nested polymerase chain reaction targeting the small subunit 18S rRNA and GP60 genes were used to detect the Cryptosporidium genotypes and subtypes. 83.8% (67 out of 80) of the specimens were positive for Cryptosporidium spp.; Cryptosporidium was found in both beef and dairy calves. Cryptosporidium parvum was the predominant species, detected in 77.5% (31/40) of beef calves and 80% (32/40) of dairy calves. Cryptosporidium bovis was also detected, 5.0% (2/40) of dairy calves, and C. ryanae was also found 2.5% (1/40) of dairy calves. One mixed-species infection, 2.5% (1/40) was detected in a beef calf having C. parvum, and C. ryanae. We detected the most common subtype of C. parvum (i.e., IIaA15G2R1), as well as other subtypes (i.e., IIaA14G3R1, IIaA14G2R1, and IIaA13G1R1) that have not previously been detected in calves in Japan. Our results demonstrate the widespread diversity of Cryptosporidium infection in calves in Japan.

Molecular identification of Eimeria hestermani and Eimeria prionotemni from a red-necked wallaby (Macropodidae; Macropus rufogriseus) in Japan

To date, more than 50 Eimeria spp. have been isolated from marsupials of the family Macropodidae. Although 18 species of Eimeria have been previously detected from multiple animal species belonging to the genus Macropus of the family, limited genetic analyses of the parasites are available, and their pathogenicity remains unclear. Here, we report the isolation of Eimeria spp. from a zoo specimen of red-necked wallaby (Macropodidae; Macropus rufogriseus). Specifically, two distinct types of Eimeria oocysts were recovered, one from the feces before treatment with an anthelmintic and the second from the intestinal contents after death of the animal. The oocysts obtained from the two sources were morphologically identified as E. hestermani and E. prionotemni, respectively. We successfully determined partial gene sequences from the two isolates, including segments of the 18S rRNA genes, and for the first time have used phylogenetic analyses of these sequences to assign the species to distinct clades. In combination with further genetic data, these results are expected to help elucidate the pathogenicity and host ranges of Eimeria spp. within the respective family and genus.

Specific increase of Fusobacterium in the faecal microbiota of neonatal calves infected with Cryptosporidium parvum

The faecal microbiota plays a critical role in host health, with alterations in the human faecal microbial composition associated with various conditions, particularly diarrhoeal diseases. However, little is known about microbial changes during cryptosporidiosis, one of the most important diarrhoeal diseases caused by protozoa in cattle. In this study, alterations in the faecal microbiota of neonatal calves as a result of Cryptosporidium parvum infection were investigated on a C. parvum-positive farm. Comparisons were made among groups of C. parvum-infected, rotavirus-infected, and the pathogen-negative calves. A specific increase in the abundance of Fusobacterium was observed in the faecal microbiota of C. parvum-infected animals. Diarrhoea severity increased in accordance with the abundance of C. parvum and Fusobacterium. Moreover, the specific increase of Fusobacterium appeared to be a universal feature of C. parvum infection, since neonatal calves from geographically separated areas showed the same result. These observations indicated that the growth of Fusobacterium may be an important aggravating factor of cryptosporidiosis.

Past and future trends of Cryptosporidium in vitro research

Cryptosporidium is a genus of single celled parasites capable of infecting a wide range of animals including humans. Cryptosporidium species are members of the phylum apicomplexa, which includes well-known genera such as Plasmodium and Toxoplasma. Cryptosporidium parasites cause a severe gastro-intestinal disease known as cryptosporidiosis. They are one of the most common causes of childhood diarrhoea worldwide, and infection can have prolonged detrimental effects on the development of children, but also can be life threatening to HIV/AIDS patients and transplant recipients. A variety of hosts can act as reservoirs, and Cryptosporidium can persist in the environment for prolonged times as oocysts. While there has been substantial interest in these parasites, there is very little progress in terms of treatment development and understanding the majority of the life cycle of this unusual organism. In this review, we will provide an overview on the existing knowledge of the biology of the parasite and the current progress in developing in vitro cultivation systems. We will then describe a synopsis of current and next generation approaches that could spearhead further research in combating the parasite.

Disinfection with hydrated lime may help manage cryptosporidiosis in calves

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Disinfection of calf pens with slaked lime delayed onset of diarrhea.

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Lime disinfection improved body condition in the calves.

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Lime disinfection did not affect diarrhea incidence or duration.

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Lime disinfection may help manage Cryptosporidium-associated diarrhea in problem herds.

Diarrhea is common in young calves and is often caused by Cryptosporidium parvum infection. The aim of this study was to investigate if disinfection of calf pens with hydrated lime would reduce contamination of C. parvum oocysts and improve calf health in herds with C. parvum associated diarrhea problems. Four dairy herds with ongoing C. parvum associated calf diarrhea problems each participated in the study over six to seven months. During the study period, all pens/huts for young calves were cleaned according to the usual farm routine before a new calf entered. Hydrated lime was then used to disinfect half of the pens/huts. Diarrhea incidence was recorded by the farmers and by veterinarians, who clinically examined the calves every second month. In total, 402 calves participated in the study. The farmers detected diarrhea in 214 (53%) calves, with similar proportions in calves kept in lime disinfected and control pens. Age at diarrhea onset was significantly higher in lime disinfected pens than in control pens, 9.0 days and 7.6 days, respectively. There was no difference between the groups regarding duration or severity index recorded by the farmers. The body condition score in 6–8 week old calves was significantly higher in calves that had been kept in lime disinfected pens during their first weeks of life, indicating that calves in disinfected pens/huts were less affected by their infections.

Faecal samples from 5 to 21 day old calves, were collected on four occasions at each farm (n = 95). Cryptosporidium positive samples were found at all samplings in all four herds. Cryptosporidium spp. was detected in 79 (83%) samples with no difference between lime disinfected and control pens. C. parvum was the dominant species. Two different C. parvum subtypes were found; IIaA16G1R1b in three herds and IIaA16G1R1b_variant in one herd. Only one subtype was found in each herd.

Disinfection of calf pens with slaked lime delayed onset of diarrhea and improved the body condition in the calves, but did not affect diarrhea incidence or duration. Although lime disinfection alone will not be sufficient to control Cryptosporidium associated diarrhea in herds with extensive calf diarrhea problems, these results suggest that it can be a valuable complement to other measures.

Development of CpGP15 recombinant antigen of Cryptosporidium parvum for detection of the specific antibodies in cattle

The infection of neonatal calves with Cryptosporidium parvum can have a huge economic impact because diarrhea caused by the parasite sometimes results in death. A serodiagnostic system will be helpful in the diagnosis of C. parvum infection. CpP23 is commonly used as an antigen for enzyme-linked immunosorbent assay (ELISA); however, some positive sera show low reactivities, as shown in this study. Herein, we focused on three other antigens, CpGP15, CpP2 and CpGP60, in addition to CpP23, to detect C. parvum-specific antibodies in cattle sera. CpP23 and CpGP15 showed substantial ability to discriminate between positive (n = 10) and negative (n = 10) control cattle sera. Unlike our previous report, both the sensitivity and the specificity were 100% when the two antigens were employed for the ELISA. The newly developed ELISA was applied to a total of 344 sera obtained from 9 cattle farms. Two farms among them had suffered from C. parvum infections before, and were regarded as the C. parvum-positive farms. The positive rates of antibodies against CpP23 and CpGP15 in the C. parvum-positive farms were 42.7% and 49.8%, respectively, whereas the positive rate for either of the antigens was 63.0% in the farms. In contrast, 14.3% and 9.8% were positive for CpP23 and CpGP15 in the C. parvum-negative farms, respectively, whereas 18.8% was positive for either of the antigens. This study revealed that the ELISAs employing both of CpP23 and CpGP15 can avoid false-negative results and are useful for monitoring of the C. parvum infection in cattle farms.

Development and evaluation of the first immunochromatographic test that can detect specific antibodies against Cryptosporidium parvum

Cryptosporidium parvum is a major cause of diarrhea among human and calves, resulting in severe health hazards and drastic economic losses, respectively. Although C. parvum infection leads to high morbidity and mortality in immunocompromised patients and bovine calves, this infection remains a neglected disease. Currently available diagnostic tests for C. parvum are primarily based on detection of oocysts, DNA, or secreted antigens in fecal specimens. Demonstration of specific antibodies with a rapid immunochromatographic test (ICT) will be advantageous not only in providing a simple, rapid, accurate, and affordable tool but also in surveillance because of the ability to recognize recent and past infections. Herein, we developed two ICTs using the diagnostic antigen CpP23 and immunodominant antigen CpGP15 to detect C. parvum-specific antibodies in cattle sera. Because of unavailability of a reference test for antibody detection, evaluation and validation of our developed ICTs were conducted using reference cattle samples and unknown field cattle sera. Serum samples were simultaneously tested by a previously validated enzyme-linked immunosorbent assay (ELISA) using the same antigens (CpGP15 and CpP23). ICTs showed substantial ability to discriminate between positive and negative control cattle sera for both CpGP15 and CpP23. Even against field sera, high sensitivity, specificity, and agreement rates were recorded for ICTs compared with the previously validated ELISA with the same antigens (CpGP15 = 78.78%, 100%, and 85.11%; CpP23 = 80%, 100%, and 80.56%, respectively). Moreover, a high correlation was observed between the test band intensity of ICTs and optical density of ELISA, particularly in the case of CpP23-specific IgM. To our knowledge, this study represents the first development of ICTs that can detect C. parvum-specific antibodies. Our tests will contribute greatly to C. parvum infection control in cattle by providing a method for on-site diagnosis of early and latent infections.

Seroprevalence of Cryptosporidium parvum and Neospora caninum in cattle in the southern Kyushu region of Japan

Cryptosporidium parvum and Neospora caninum are common parasites in domesticated cattle worldwide, including in Japan. We carried out a serological survey to detect C. parvum and N. caninum infection among cattle in the southern Kyushu region of Japan-including the small islands-by indirect enzyme-linked immunosorbent assay based on recombinant antigens. We found that total seropositivity in 570 Japanese black cattle was 96.3% for C. parvum and 18.4% for N. caninum. Although seroprevalence was correlated with cattle age, differences in the seroprevalence of C. parvum among age groups were not statistically significant. On the other hand, N. caninum seroprevalence increased with age, suggesting horizontal transmission through ingestion of food or water contaminated with oocysts. These findings underscore the importance of monitoring C. parvum and N. caninum in cattle and implementing measures to prevent the spread of infection to other livestock and to humans.

Molecular identification of two Eimeria species, E. uekii and E. raichoi as type B, in wild Japanese rock ptarmigans, Lagopus muta japonica

Thus far, two types of Eimeria parasites (E. uekii and type B) have been morphologically identified in wild Japanese rock ptarmigans, Lagopus muta japonica. Although high prevalences were reported for these parasites, genetic analyses have not been conducted. We first clarified the phylogenetic positions of two eimerian isolates using genetic analyses of 18S rRNA and mitochondrial cytochrome c oxidase subunit I gene regions. Consequently, of 61 samples examined, 21 and 11 samples were positive for E. uekii and type B, respectively. Additionally, the infection rate increased in the summer. Molecular analyses revealed both Eimeria isolates formed their own clusters; E. uekii was included in clades of chicken Eimeria and type B was include in clades of turkey Eimeria. Based on our findings in this study and previous data, we herein propose type B as E. raichoi. These genetic data will be helpful to conduct detailed classification and understand the impact of these parasites for conservation of endangered Japanese rock ptarmigans.

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Molecular analyses revealed Eimeria isolates from Japanese rock ptarmigans formed own clades.

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The species was phylogenetically closely related to virulent chicken Eimeria spp.

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Based on morphological data and sequences, Eimeria type B was proposed as a new species E. raichoi.

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These parasites could be the key factor for conservation of the endangered birds.

Surveillance of Eimeria species in wild Japanese rock ptarmigans, Lagopus muta japonica, and insight into parasitic seasonal life cycle at timberline regions of the Japanese Alps

The Japanese rock ptarmigan, Lagopus muta japonica, inhabits the alpine zone of mountainous areas at 3000 m above sea level. Since L. m. japonica is endangered due to a decline in the overall population, controlling infectious diseases such as those caused by protozoan parasites is a critical factor in the conservation of this species. Although Eimeria spp. are considered to have a negative impact on Japanese rock ptarmigan populations, the ecological interactions between the parasites and their hosts have not yet been fully clarified. We therefore conducted seasonal surveys of the prevalence of Eimeria spp. in Japanese rock ptarmigan populations. In addition, we recorded the ambient temperature in ptarmigan habitat and characterized the ability of eimerian isolates to acquire infectivity. Eimeria spp. were detected in 217 of 520 (41.7%) Japanese rock ptarmigan fecal samples in 2006 and in 177 of 308 (57.5%) fecal samples in 2007. Specifically, we observed two types of oocysts characteristic of E. uekii and type B. In adult birds and chicks, infection rates increased towards August (summer) and then decreased as the temperature decreased toward November (winter). Oocyst counts per gram (OPG) of feces peaked in August in adults and chicks, and OPG values were markedly higher in chicks than in adults. Isolated Eimeria spp. oocysts sporulated at temperatures as low as 8 °C and remained viable after being stored at 4 °C for 6 months. Our findings suggest that Eimeria spp. can complete their annual lifecycle in the cold timberline regions inhabited by the host, the Japanese rock ptarmigan, and that Eimeria spp. infection is widespread in the bird populations examined.

Pathogenic characteristics of a novel intranuclear coccidia in Japanese black calves and its genetic identification as Eimeria subspherica

Bovine intranuclear coccidiosis is caused by the protozoans Eimeria alabamensis and Cyclospora spp. Here, we characterized the disease and genetically identified the causative species in Japanese black calves with chronic and refractory watery diarrhea. Histologic examinations revealed atrophy of the jejunal villi and numerous parasites in the nucleus of epithelial cells in the jejunum. Based on molecular analyses using 18S ribosomal RNA gene-specific primers that we designed, the parasites were found to be formed in the same cluster as Eimeria subspherica in the phylogenetic tree, which was separated from those of other related Eimeria spp. These results constitute the first report of E. subspherica as a cause of bovine intranuclear coccidiosis.

Alterations in oxidative stress parameters and its associated correlation with clinical disease on experimental Cryptosporidium parvum infection in Swiss albino mice

The present study was conducted to evaluate the changes in oxidative stress parameters on experimental infection with Cryptosporidium parvum in Swiss albino mice. The mice were divided into four groups viz., group I-IV, each group comprising of 15 mice. Group I mice served as healthy control. In Group II mice, C. parvum oocysts @ 104/os were administered, mice of group III were given dexamethasone @ 30 µg/ml in drinking water whereas group IV mice were given dexamethasone @ 30 µg/ml along with C. parvum oocysts @ 104/os. Significant changes were seen in oxidative stress parameters which included significant increase in LPO and decrease in levels of SOD, CAT and GSH in liver and intestine in group IV mice at 10th DPI when compared to others indicating an important role played by free radical induced oxidative stress in the development of C. parvum infection in mice which was clinically characterized by loss of body condition, profuse bloody diarrhoea and peak oocyst shedding intensity occurring at 10th DPI.

Development of molecular diagnostic protocols for detecting three types of Entamoeba from diarrheal and asymptomatic pigs and environmental moist soils

Entamoeba suis and Entamoeba polecki subtypes (ST) 1 and 3 have recently been implicated in disease outbreaks in pigs. However, the distributions of these parasites in Japan and the potential sources of infection on farms still remain unclear. Here, we examined a farm of fattening/growing pigs with abnormal feces in Kagoshima Prefecture, Japan, and found the presence of parasites in the farm environment. Examination of intestinal tissues from pigs presenting with ulcerative colitis revealed a large number of trophozoites that had invaded the lesions. We identified single and mixed infections of E. suis and E. polecki ST1 and ST3 in paraffin sections or fecal samples from affected pigs. Two subtypes of Entamoeba were identified using four primer sets by PCR and sequencing. The parasites were detected in moist soil samples obtained around the drinking water source or puddles, implicating transmission of cysts via contaminated soils. Additionally, we found evidence of Entamoeba spp. and coinfections in surveyed pigs without any diarrhea at two neighboring farms. Our results establish methods for successfully identification of parasites, including cases in which multiple infections are present.

Report of fatal mixed infection with Cryptosporidium parvum and Giardia intestinalis in neonatal calves

In the production and management of beef and dairy cattle, controlling diarrhea is one of the important concerns. Pathogenic agents of the disease, protozoan parasites including Cryptosporidium spp., are difficult to control, making prevention, diagnoses, and treatment of diarrhea. In the present study, we investigated a farm with a history of calf deaths over a period of 10 years in order to determine the cause of disease and to clarify the detailed distribution of the pathogens. In four examined calves that were reared in calf pens, all were positive with Cryptosporidium and/or Giardia, while the other breeding stock and adult cattle were negative. Molecular analyses revealed that the isolates from calves were C. parvum subtype IIaA15G2R1 as a zoonotic and G. intestinalis assemblage E. Other pathogenic bacteria and diarrhea-causing viruses were not detected. After treating the calf pens with boiling water and milk of lime (Ca[OH]2), oocysts of C. parvum and cysts of G. intestinalis were not found and no additional calves died. This is the first report to describe the mixed infection of both parasites in Japan.

Bovine TLR2 and TLR4 mediate Cryptosporidium parvum recognition in bovine intestinal epithelial cells

Cryptosporidium parvum (C. parvum) is an intestinal parasite that causes diarrhea in neonatal calves. It results in significant morbidity of neonatal calves and economic losses for producers worldwide. Innate resistance against C. parvum is thought to depend on engagement of pattern recognition receptors. However, the role of innate responses to C. parvum has not been elucidated in bovine. The aim of this study was to evaluate the role of TLRs in host-cell responses during C. parvum infection of cultured bovine intestinal epithelial cells. The expressions of TLRs in bovine intestinal epithelial cells were detected by qRT-PCR. To determine which, if any, TLRs may play a role in the response of bovine intestinal epithelial cells to C. parvum, the cells were stimulated with C. parvum and the expression of TLRs were tested by qRT-PCR. The expression of NF-κB was detected by western blotting. Further analyses were carried out in bovine TLRs transfected HEK293 cells and by TLRs-DN transfected bovine intestinal epithelial cells. The results showed that bovine intestinal epithelial cells expressed all known TLRs. The expression of TLR2 and TLR4 were up-regulated when bovine intestinal epithelial cells were treated with C. parvum. Meanwhile, C. parvum induced IL-8 production in TLR2 or TLR4/MD-2 transfected HEK293 cells. Moreover, C. parvum induced NF-κB activation and cytokine expression in bovine intestinal epithelial cells. The induction of NF-κB activation and cytokine expression by C. parvum were reduced in TLR2-DN and TLR4-DN transfected cells. The results showed that bovine intestinal epithelial cells expressed all known TLRs, and bovine intestinal epithelial cells recognized and responded to C. parvum via TLR2 and TLR4.

First molecular identification of Entamoeba polecki in a piglet in Japan and implications for aggravation of ileitis by coinfection with Lawsonia intracellularis

Parasitic Entamoeba spp. are found in many vertebrate species including humans, as well as many livestock including pigs. In pigs, three Entamoeba spp., E. suis, and E. polecki and E. histolytica as zoonotic species, have been identified, but their pathogenicity has not been fully characterized. Here, we report the bacteriological, virological, and histopathological examination of three piglets with chronic diarrhea. Two animals appeared to be additionally infected with Lawsonia intracellularis, which caused a characteristic proliferative ileitis. In the piglet infected with Entamoeba spp., the trophozoites (approximately 10-15 μm with one nucleus in their cytoplasm) invaded into the lamina propria and the disease was worsened by the formation of ulcers and pseudomembranes. Genetic analysis identified the parasite as E. polecki (99.5% identity). Although E. polecki in humans or animals might be less pathogenic in the case of a single infection, coinfections with other pathogens including L. intracellularis may increase the severity of the disease.

Prevalence of Cryptosporidium spp. in ruminants of Lorestan province, Iran

Cryptosporidiosis is one of the important zoonotic diseases caused by an intracellular protozoan parasite called Cryptosporidium. This study aimed to investigate the prevalence of Cryptosporidium spp. infection on 1,115 ruminants, cattle, sheep and goats, in Lorestan province, Iran. Using formol-ether concentration technique and modified Ziehl-Neelsen staining method afterwards, the overall prevalence of Cryptosporidium spp. infection in ruminants of Lorestan province was 7.17 %. Prevalence of infection was 9.07 % (39 of 430), 5.80 % (20 of 345) and 6.18 % (21 of 340) for cattle, sheep and goats respectively. There was no significant difference between contamination of all examined animals and different geographical and climatic situations (P > 0.05) and diarrhea was not directly associated with Cryptosporidium infection (P > 0.05). In conclusion, the prevalence of cryptosporidiosis in Lorestan province was relatively low, but it should be noticed that this opportunistic parasite is zoonosis and also can make epidemics in ruminants as well as human population in suitable conditions.

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.

Cryptosporidiosis in Farmed Animals

Cryptosporidiosis was first identified as a disease of veterinary, rather than human medical, importance, and infection of farmed animals with different species of Cryptosporidium continues to be of veterinary clinical concern. This chapter provides insights into Cryptosporidium infection in a range of farmed animals – cattle, sheep, goats, pigs, cervids, camelids, rabbits, water buffalo and poultry – presenting not only an updated overview of the infection in these animals, but also information on clinical disease, infection dynamics and zoonotic potential. Although extensive data have been accrued on, for example, Cryptosporidium parvum infection in calves, and calf cryptosporidiosis continues to be a major veterinary concern especially in temperate regions, there remains a paucity of data for other farmed animals, despite Cryptosporidium infection causing significant clinical disease and also, for some species, with the potential for transmission of infection to people, either directly or indirectly.

Molecular characterization of Cryptosporidium isolates from calves in Ishikari District, Hokkaido, Japan

Cattle are major hosts of Cryptosporidium. Cryptosporidiosis in neonatal calves is associated with retarded growth, weight loss and calf mortality, and zoonotic infections in humans. Fecal samples were collected from calves in Ishikari District, Hokkaido, Japan and examined by PCR and sequence analyses. Among the 107 fecal samples collected in May and June 2012, 25 (23%) were positive for Cryptosporidium, including 8 samples (7%) having C. parvum, 10 (9%) having C. bovis and 7 (7%) having C. ryanae. This is first time C. ryanae has been detected in Hokkaido. Furthermore, it is the first detection of C. ryanae from pre-weaned calves in Japan. Microscopic observation with the flotation method is powerful and traditional tool for screening for Cryptosporidium species, but it sometimes leads to low detection of Cryptosporidium with low oocyst shedding intensity. If calves with or without diarrhea are examined using the molecular diagnostic tools, C. bovis and C. ryanae might be detected in other areas of Japan including Hokkaido. Here, the zoonotic species, C. parvum, was also observed. Therefore, calves can be potential sources of cryptosporidial infections for humans and other animals. The detection of C. parvum was statistically correlated with diarrhea in calves.

Foodborne cryptosporidiosis: is there really more in Nordic countries?

Most waterborne outbreaks of cryptosporidiosis are reported from the USA, and in Europe from the UK. However, since 2000 reports of foodborne cryptosporidiosis seem to be skewed towards Nordic countries, although consumers in these countries are apparently less concerned about microbiological contamination of food than consumers elsewhere. Possible reasons for this unexpected geographical distribution might include prolonged survival of oocysts in the Nordic climate, greater exposure due to elevated consumption of higher-risk products (possibly including imported foods), and better outbreak investigation and reporting. Although the risk of foodborne cryptosporidiosis is probably underestimated globally, we suggest that the next outbreak is no more likely to be in a Nordic country than anywhere else.

Detection of Cryptosporidium parvum oocysts in calf fecal samples by direct immunofluorescence assay

The aim of this study was to produce a conjugate containing anti-Cryptosporidium parvum polyclonal antibodies and standardize a Direct Immunofluorescence Assay (DIF) for detecting C. parvum oocysts in fecal samples from calves. In order to obtain anti-C. parvum polyclonal antibodies, two New Zealand rabbits were immunized with a purified solution of C. parvum oocysts and Freund's adjuvant. Purification of the immunoglobulin G (IgG) fraction was performed by means of precipitation in ammonium sulfate and chromatography using a DEAE-cellulose column. The anti-C. parvum polyclonal antibody titer was determined by means of the enzyme-linked immunosorbent assay (ELISA). The rabbit anti-C. parvum IgG fraction was conjugated with fluorescein isothiocyanate and standardization of the DIF was performed using various dilutions of conjugate on slides positive for C. parvum oocysts. The cross-reactivity of the anti-C. parvum conjugate was tested using oocysts of Cryptosporidium serpentis, Cryptosporidium andersoni, Escherichia coli, Eimeria sp., and Candida sp. An anti-C. parvum conjugate was successfully produced, thus allowing standardization of DIF for detection of Cryptosporidium oocysts in fecal samples. Cross-reactivity of anti-C. parvum polyclonal antibodies with C. andersoni and C. serpentis was also observed.

First description of Cryptosporidium bovis in Japan and diagnosis and genotyping of Cryptosporidium spp. in diarrheic pre-weaned calves in Hokkaido

Eighty fecal samples from pre-weaned calves with diarrhea were collected in the Tokachi area in Northern Japan to investigate the prevalence of Cryptosporidium species in such animals. Oocysts from fecal samples collected from each animal were concentrated using sucrose gradient centrifugation. Genomic DNA was extracted from each sample and processed by nested PCR to amplify the partial SSU rRNA gene of Cryptosporidium. Cryptosporidium infections were detected in 75% of the samples. Sequence analysis was performed on all positive samples. Phylogenetic analysis of 33 successfully sequenced isolates of the SSUrRNA PCR products revealed all but one were Cryptosporidium parvum infections. The remaining single case was Cryptosporidium bovis. These findings suggest that C. parvum is prevalent in diarrheic pre-weaned calves and can be a source of cryptosporidial infections for humans and animals in Hokkaido.

Prevalence and associated management factors of Cryptosporidium shedding in 50 Swedish dairy herds

Cryptosporidium parvum is a protozoan parasite causing diarrhoea in young calves. This cross-sectional study was performed to estimate the prevalence of Cryptosporidium infected herds in a sample of Swedish dairy herds and to identify potential risk factors associated with shedding of oocysts. Fifty dairy herds, selected by stratified random sampling, were included. The herds were visited once during the indoor seasons of 2005-2006 and 2006-2007. Faecal samples were collected from 10 calves, 10 young stock and 5 cows in each herd. Clinical observations of sampled animals and environmental status were recorded, and farmers were interviewed about management procedures. Faecal samples were cleaned by sodium chloride flotation and detection of oocysts was made by epifluorescence microscopy. Cryptosporidium parvum-like oocysts were found in 96% of the herds. Prevalence was 52% in calves, 29% in young stock and 5.6% in cows. Three two-day-old calves shed oocysts. Cryptosporidium andersoni was found in seven animals from four different herds. Factors associated with prevalence of shedders among sampled animals in a herd were age at weaning, cleaning of single calf pens, placing of young stock, system for moving young stock, and year of sampling. Factors associated with shedding in calves were age, placing of young stock, routines for moving young stock and time calf stays with the cow. The only significant factor in young stock was age. In cows, number of calves in the herd and type of farming (organic vs. conventional) affected shedding.

Feeding activated charcoal from bark containing wood vinegar liquid (nekka-rich) is effective as treatment for cryptosporidiosis in calves

The effect of activated charcoal containing wood vinegar liquid (Nekka-Rich) on Cryptosporidium parvum was evaluated in vitro and in vivo. First, the adsorption of C. parvum by the activated charcoal component of Nekka-Rich was examined. When mixed, C. parvum oo-cysts were effectively adsorbed by activated charcoal. Next, the effect of the wood vinegar liquid component of Nekka-Rich was assessed. Wood vinegar liquid had an antiprotozoan activity against C. parvum oocysts. Finally, the anticryptosporidial effect of Nekka-Rich was evaluated in calves experimentally infected with C. parvum. Six neonatal calves at 7 d of age were orally infected with 1 x 10(5) oocysts of C. parvum. When diarrhea was observed (on d 3 after the experimental infection), 3 calves received a milk replacer containing 10 g of Nekka-Rich at 8-h intervals for 4 consecutive days, and 3 control calves were given a milk replacer without Nekka-Rich at 8-h intervals for 4 consecutive days. Calves fed milk with Nekka-Rich showed recovery from diarrhea 1 d after the start of treatment. Significantly less fecal excretion of C. parvum oocysts was observed 1 d after treatment in calves fed Nekka-Rich. On d 2 from the beginning of treatment with Nekka-Rich (on d 5 after the experimental infection), oocysts were not isolated from fecal samples. On the other hand, nontreated control calves developed severe diarrhea, and fecal excretion of oocysts was consistently observed. Calves in both groups were killed for collection of samples, which were subjected to scanning electron microscopy. Scanning electron microscopy revealed adherence of C. parvum oocysts to the intestinal epithelial surface of nontreated control calves, whereas a lack of C. parvum adhesion was observed in calves fed Nekka-Rich. These results suggest that Nekka-Rich would be useful for the treatment of cryptosporidiosis in neonatal calves.

A longitudinal study of cryptosporidiosis in dairy cattle from birth to 2 years of age

Fecal specimens were collected from 30 calves from birth to 24 months of age at a dairy farm in Maryland to determine the prevalence and age distribution of Cryptosporidium species/genotypes. After centrifugation to remove debris and concentrate oocysts, specimens were examined by immunofluorescence microscopy and polymerase chain reaction (PCR). Fragments of the SSU-rDNA gene amplified by PCR were purified and PCR products were sequenced. All 30 calves shed Cryptosporidium oocysts at some time during the 24 months of the study. Of 990 specimens, 190 were Cryptosporidium-positive (19.2%). The highest prevalence of infection was at 2 weeks of age when 29 of the 30 calves were excreting oocysts. Prevalence was higher in pre-weaned calves (1-8 weeks of age) (45.8%) than in post-weaned calves (3-12 months of age) (18.5%) and heifers (12-24 months of age) (2.2%). Sequence data for 190 PCR-positive specimens identified: C. parvum, C. bovis, the Cryptosporidium deer-like genotype and C. andersoni, with cumulative prevalences of 100, 80, 60, and 3.3%, respectively. C. parvum constituted 97% of infections in pre-weaned calves but only 4% and 0% of infections in post-weaned calves and heifers, respectively. All C. parvum GP60 nucleotide sequences were subtype IIaA15G2R1.

Detection of bovine torovirus in fecal specimens of calves with diarrhea in Japan

The aim of this study was to determine the prevalence of bovine torovirus (BoTV) in bovine fecal samples and to determine whether a relationship exists between BoTV and diarrhea in Japan. Ninety-nine diarrheic and 114 normal fecal samples from calves in Hokkaido Prefecture and 38 diarrheic fecal samples from calves in 10 other prefectures were examined by reverse transcription (RT)-PCR with primers designed in the spike (S) gene for the presence of BoTV. The specimens were also examined for the presence of other enteric pathogens, bovine rotavirus, coronavirus and Cryptosporidium spp. BoTV RNA was detected in 15 (15.2%) of the 99 diarrheic samples from Hokkaido and in 9 (23.7%) of the 38 diarrheic samples from the other prefectures. The incidence of BoTV in control specimens was 7.0%. In 11 of the 15 BoTV-positive specimens from Hokkaido, BoTV was the only pathogen detected among those examined, and 11 BoTV-positive specimens were obtained from calves less than 2 weeks of age. Rotavirus was confirmed to be associated with calf diarrhea, but coronavirus and Cryptosporidium spp. were not. Nucleotide sequences of 17 different BoTV RT-PCR products were determined. Phylogenetic analysis based on the sequences revealed that Japanese BoTVs could be classified into at least two groups. This study showed that BoTV is a common virus in fecal specimens of calves with diarrhea in Japan and may be an important pathogen of cattle, principally in young calves less than 2 weeks of age.

Developing risk models of Cryptosporidium transport in soils from vegetated, tilted soilbox experiments

Transport of Cryptosporidium parvum through macroporous soils is poorly understood yet critical for assessing the risk of groundwater contamination. We developed a conceptual model of the physics of flow and transport in packed, tilted, and vegetated soilboxes during and immediately after a simulated rainfall event and applied it to 54 experiments implemented with different soils, slopes, and rainfall rates. Using a parsimonious inverse modeling procedure, we show that a significant amount of subsurface outflow from the soilboxes is due to macropore flow. The effective hydraulic properties of the macropore space were obtained by calibration of a simple two-domain flow and transport model that accounts for coupled flow in the matrix and in the macropores of the soils. Using linear mixed-effects analysis, macropore hydraulic properties and oocyst attenuation were shown to be associated with soil bulk density and rainfall rate. Macropore flow was shown to be responsible for bromide and C. parvum transport through the soil into the underlying pore space observed during the 4-h experiments. We confirmed this finding by conducting a pair of saturated soil column studies under homogeneously repacked conditions with no macropores in which no C. parvum transport was observed in the effluent. The linear mixed-effects and logistic regression models developed from the soilbox experiments provide a basis for estimating macropore hydraulic properties and the risk of C. parvum transport through shallow soils from bulk density, precipitation, and total shallow subsurface flow rate. The risk assessment is consistent with the reported occurrence of oocysts in springs or groundwater from fractured or karstic rocks protected only by shallow overlying soils.

Detection of a mixed infection of a novel Cryptosporidium andersoni and its subgenotype in Japanese cattle

Cryptosporidium oocysts were detected in the feces of cattle in Saga, Japan. Isolates were morphologically large. We attempted to identify the species or genotypes of the isolates by analyzing the partial sequences of the 18S rRNA and Cryptosporidium oocyst wall protein (COWP) genes, and measuring the infectivity in mice. The isolates showed 100% homology with Cryptosporidium andersoni in the COWP gene sequence and it could be transmitted to mice, but in the 18S rRNA gene, there was an additional signal in the ABI sequence chromatogram. To examine the additional signal, we analyzed both the 18S rRNA and the COWP gene sequences of a single oocyst passaged from mice using a modified multiplex PCR that was able to amplify both genes. As a result, it was revealed that two distinct genotypes (Types A and B) of a novel C. andersoni type existed in the 18S rRNA gene, whereas the COWP gene sequences of both oocysts were identical to C. andersoni. Although the sequence of the 18S rRNA gene of Type A was identical to that of C. andersoni, that of Type B had a thymine insertion and was not identical to any sequence registered with GenBank. Here we report that this is a new type of C. andersoni.

Prevalence and molecular characterization of Giardia duodenalis and Cryptosporidium spp. in dairy cattle in Ontario, Canada

Giardia duodenalis and Cryptosporidium spp. are intestinal protozoan parasites that infect a wide range of host species, including humans. Molecular characterization of these parasites has demonstrated that a number of genotypes and species are common to both humans and animals, and that zoonotic transmission may occur. Numerous studies have reported a high prevalence of G. duodenalis and Cryptosporidium spp. in cattle, particularly calves, and these animals are frequently associated with zoonotic transmission. In the present study, a total of 143 faecal samples from adults, heifers and calves were collected from two dairy cattle farms in eastern Ontario, Canada. The prevalence and molecular characteristics of G. duodenalis and Cryptosporidium spp. in these animals were determined in order to investigate the potential for transmission between cattle and humans in this region. Following DNA extractions from faecal samples, nested-PCR protocols were used to amplify fragments of the 16S rRNA gene and the heat-shock protein 70 (HSP-70) gene for determining the prevalence of G. duodenalis and Cryptosporidium spp. infections, respectively. Genotypes of G. duodenalis, and species of Cryptosporidium, were determined by means of DNA sequencing of amplicons, and subsequent sequence alignment. Cattle on both farms showed a high prevalence of G. duodenalis (42.0%) and Cryptosporidium spp. (27.3%). G. duodenalis infections were more prevalent in calves and heifers than in adults, and Cryptosporidium spp. infections were only observed in calves and heifers. The zoonotic genotype, G. duodenalis Assemblage B was isolated from 24.5% of the cattle tested, while G. duodenalis Assemblage E was found in 17.5% of the cattle tested. The overall prevalence of the zoonotic species Cryptosporidium parvum in the animals tested was found to be 21.7%, while only 1.4% were infected with C. bovis. These findings suggest that there is a potential risk of zoonotic and/or zooanthroponotic transmission of G. duodenalis and C. parvum infections between cattle and humans in eastern Ontario, likely by means of contaminated water or food, or through direct faecal-oral transmission in the case of farmers and veterinary staff.

Prevalence of Cryptosporidium infection in cattle in Isfahan, Iran

Cryptosporidium are commonly identified as intestinal pathogens in humans and animals. Fecal samples from 480 cattle randomly selected from 30 regions in Isfahan, Iran, were examined to investigate the prevalence of Cryptosporidium infection. Cryptosporidium oocysts were identified by using sheather's concentration and the Ziehl-Neelsen modified staining technique in 30 of 480 cattle ranging from less than 6 mo of age to older than 1 yr of age. Infected animals were found in 86.6% (26/30) of regions investigated. Overall prevalence of infection was 6.25%, but higher in cattle less than 6 mo of age (10.8%) and this was statistically significant (P<0.05). Both sexes of cattle were infected with Cryptosporidium parasites, but prevalences were higher in diarrheic (56.7%) than in non-diarrheic (39%) cattle. Cryptosporidium appears to be prevalent in cattle in Isfahan.