Subtyping Cryptosporidium ubiquitum,a zoonotic pathogen emerging in humans

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.

Subtype Characterization and Zoonotic Potential of Cryptosporidium felis in Cats in Guangdong and Shanghai, China

Cryptosporidiumfelis is an important cause of feline and human cryptosporidiosis. However, the transmission of this pathogen between humans and cats remains controversial, partially due to a lack of genetic characterization of isolates from cats. The present study was conducted to examine the genetic diversity of C. felis in cats in China and to assess their potential zoonotic transmission. A newly developed subtyping tool based on a sequence analysis of the 60-kDa glycoprotein (gp60) gene was employed to identify the subtypes of 30 cat-derived C. felis isolates from Guangdong and Shanghai. Altogether, 20 C. felis isolates were successfully subtyped. The results of the sequence alignment showed a high genetic diversity, with 13 novel subtypes and 2 known subtypes of the XIXa subtype family being identified. The known subtypes were previously detected in humans, while some of the subtypes formed well-supported subclusters with human-derived subtypes from other countries in a phylogenetic analysis of the gp60 sequences. The results of this study confirmed the high genetic diversity of the XIXa subtype family of C. felis. The common occurrence of this subtype family in both humans and cats suggests that there could be cross-species transmission of C. felis.

Cryptosporidium Species and C. parvum Subtypes in Farmed Bamboo Rats

Bamboo rats (Rhizomys sinensis) are widely farmed in Guangdong, China, but the distribution and public health potential of Cryptosporidium spp. in them are unclear. In this study, 724 fecal specimens were collected from bamboo rats in Guangdong Province and analyzed for Cryptosporidium spp. using PCR and sequence analyses of the small subunit rRNA gene. The overall detection rate of Cryptosporidium spp. was 12.2% (88/724). By age, the detection rate in animals under 2 months (23.2% or 13/56) was significantly higher than in animals over 2 months (11.2% or 75/668; χ² = 6.95, df = 1, p = 0.0084). By reproduction status, the detection rate of Cryptosporidium spp. in nursing animals (23.1% or 27/117) was significantly higher than in other reproduction statuses (6.8% or 4/59; χ² = 7.18, df = 1, p = 0.0074). Five Cryptosporidium species and genotypes were detected, including Cryptosporidium bamboo rat genotype I (n = 49), C. parvum (n = 31), Cryptosporidium bamboo rat genotype III (n = 5), C. occultus (n = 2), and C. muris (n = 1). The average numbers of oocysts per gram of feces for these Cryptosporidium spp. were 14,074, 494,636, 9239, 394, and 323, respectively. The genetic uniqueness of bamboo rat genotypes I and III was confirmed by sequence analyses of the 70 kDa heat shock protein and actin genes. Subtyping C. parvum by sequence analysis of the 60 kDa glycoprotein gene identified the presence of IIoA15G1 (n = 20) and IIpA6 (n = 2) subtypes. The results of this study indicated that Cryptosporidium spp. are common in bamboo rats in Guangdong, and some of the Cryptosporidium spp. in these animals are known human pathogens.

Subtype distribution of zoonotic pathogen Cryptosporidium felis in humans and animals in several countries

Cryptosporidium felis is the major etiologic agent of cryptosporidiosis in felines and has been reported in numerous human cryptosporidiosis cases. Sequence analysis of the 60-kDa glycoprotein (gp60) gene has been developed for subtyping C. felis recently. In this study, 66 C. felis isolates from the United States, Jamaica, Peru, Portugal, Slovakia, Nigeria, Ethiopia, Kenya, China, India and Australia were subtyped using the newly established tool. Forty-four specimens yielded gp60 sequences, generating 23 subtypes clustered in 4 subtype families (XIXa, XIXc, XIXd and XIXe) with high bootstrap support in a phylogenetic analysis of sequence data. Among them, XIXa showed high genetic diversity at the nucleotide level, with the formation of 18 subtypes from both cats and humans with different geographic distribution. In contrast, all 11 XIXd isolates derived from humans from various countries had identical sequences. Results of this study improve our understanding of the genetic diversity, host specificity and transmission dynamics of C. felis.

Genetic Diversity of Cryptosporidium in Bactrian Camels (Camelus bactrianus) in Xinjiang, Northwestern China

Cryptosporidium species are ubiquitous enteric protozoan pathogens of vertebrates distributed worldwide. The purpose of this study was to gain insight into the zoonotic potential and genetic diversity of Cryptosporidium spp. in Bactrian camels in Xinjiang, northwestern China. A total of 476 fecal samples were collected from 16 collection sites in Xinjiang and screened for Cryptosporidium by PCR. The prevalence of Cryptosporidium was 7.6% (36/476). Six Cryptosporidium species, C. andersoni (n = 24), C. parvum (n = 6), C. occultus (n = 2), C. ubiquitum (n = 2), C. hominis (n = 1), and C. bovis (n = 1), were identified based on sequence analysis of the small subunit (SSU) rRNA gene. Sequence analysis of the gp60 gene identified six C. parvum isolates as subtypes, such as If-like-A15G2 (n = 5) and IIdA15G1 (n = 1), two C. ubiquitum isolates, such as subtype XIIa (n = 2), and one C. hominis isolate, such as Ixias IkA19G1 (n = 1). This is the first report of C. parvum, C. hominis, C. ubiquitum, and C. occultus in Bactrian camels in China. These results indicated that the Bactrian camel may be an important reservoir for zoonotic Cryptosporidium spp. and these infections may be a public health threat in this region.

Cryptosporidium infections in sheep farms from Italy

Cryptosporidiosis is recognized as being a significant cause of gastrointestinal illness due to its wide range of vertebrate hosts, including humans. Infection with Cryptosporidium spp. is especially common in young domestic ruminants (calves, lambs and goat kids) and has been associated with economic losses worldwide. In contrast to cattle, to date, detailed studies on Cryptosporidium infections in sheep from Europe are still limited; thus, their importance as reservoirs of Cryptosporidium species with implications on animal and public health still needs to be clarified. This study evaluates the prevalence and zoonotic potential of Cryptosporidium spp. in sheep farms in Italy. A total of 915 individual faecal samples divided into three different animal categories were collected from 61 sheep farms. Each sample was examined by microscopy of faecal smears stained by modified Ziehl-Neelsen and by biomolecular techniques. Cryptosporidium oocysts were detected in 10.1% of the animals examined and in 34.4% of the farms. The prevalence of Cryptosporidium spp. was significantly higher (χ² = 51.854; P < 0.001) in diarrhoeic samples than in pasty or normal faeces. Genotype analyses showed the presence of two Cryptosporidium species: C. parvum and C. ubiquitum. Subtyping analysis of C. parvum isolates revealed the presence of subtypes IIa15G2R1 and IIdA20G1 and of subtype XIIa for C. ubiquitum. These findings have public health implications since both Cryptosporidium species identified are considered zoonotic, and C. parvum is the second-most common Cryptosporidium species infecting humans. Our data reveal that lambs, especially those excreting diarrhoeic faeces, may be important reservoirs of Cryptosporidium. We also highlight the need to establish adequate control and monitoring programmes for the control of this infection in sheep farms primarily through coprological monitoring.

Cryptosporidium and Giardia in dam water on sheep farms - An important source of transmission?

Cryptosporidium and Giardia infections can negatively impact livestock health and reduce productivity, and some species and genotypes infecting livestock have zoonotic potential. Infection occurs via the faecal-oral route. Waterborne infections are a recognised source of infection for humans, but the role of livestock drinking water as a source of infection in livestock has not been described. This study aimed to determine whether contaminated drinking water supplies, such as farm dams, are a likely transmission source for Cryptosporidium and Giardia infections for extensively managed sheep. Dam water samples (n = 47) were collected during autumn, winter and spring from 12 farm dams located on six different farms in south west Western Australia, and faecal samples (n = 349) were collected from sheep with access to these dams. All samples were initially screened for Cryptosporidium spp. at the 18S locus and Giardia spp. at the gdh gene using qPCR, and oocyst numbers were determined directly from the qPCR data using DNA standards calibrated by droplet digital PCR. Cryptosporidium-positive sheep faecal samples were typed and subtyped by sequence analysis of 18S and gp60 loci, respectively. Giardia-specific PCR and Sanger sequencing targeting tpi and gdh loci were performed on Giardia- positive sheep faecal samples to characterise Giardia duodenalis assemblages. To identify Cryptosporidium and Giardia spp. in dam water samples, next-generation sequencing analysis of 18S and gdh amplicons were performed, respectively. Two species of Cryptosporidium (Cryptosporidium xiaoi and Cryptospordium ubiquitum (subtype family XIIa)) were detected in 38/345 sheep faecal samples, and in water from 9/12 farm dams during the study period, with C. xiaoi the species most frequently detected in both faeces and dam water overall. Giardia duodenalis assemblages AI, AII and E were detected in 36/348 faecal samples and water from 10/12 farm dams. For dam water samples where oo/cysts were detected by qPCR, Cryptosporidium oocyst concentration ranged from 518-2429 oocysts/L (n = 14), and Giardia cyst concentration ranged from 102 to 1077 cysts/L (n = 17). Cryptosporidium and Giardia with zoonotic potential were detected in farm dam water, including C. ubiquitum, C. hominis, C. parvum, C. cuniculus, C. xiaoi, and G. duodenalis assemblages A, B and E. The findings suggest that dam water can be contaminated with Cryptosporidium species and G. duodenalis assemblages that may infect sheep and with zoonotic potential, and farm dam water may represent one source of transmission for infections.

Cryptosporidium Infections in Africa-How Important Is Zoonotic Transmission? A Review of the Evidence

Cryptosporidium, a protozoan parasite in the phylum Apicomplexa, is the etiological agent of cryptosporidiosis, an intestinal infection characterized by profuse watery diarrhea. Over 30 species of Cryptosporidium are recognized, some host specific whereas others infect a broader host range. Cryptosporidium hominis and Cryptosporidium parvum are the species most commonly associated with human infection; C. hominis is largely associated only with human infections, but C. parvum is also associated with infection in animals, especially young ruminants. In some regions, cryptosporidiosis is a serious veterinary problem, particularly for calves, and lambs. Many outbreaks of human cryptosporidiosis have been associated with zoonotic transmission following contact with infected animals. In Africa, where cryptosporidiosis is a major contributor to pediatric morbidity and mortality, evidence suggests transmission is principally anthroponotic. Given the frequent close contact between humans and animals in Africa, the apparent predominance of human-to-human transmission is both interesting and puzzling. In this article, after a brief "text book" introduction to the parasite, we consider in separate sections the different aspects of relevance to Cryptosporidium transmission in African countries, describing different aspects of the various species and subtypes in human and animal infections, considering livestock management practices in different African countries, and looking for any characteristic "hot spots" where zoonotic transmission has apparently occurred. Studies where transmission networks have been investigated are particularly relevant. Finally, in a separate section, we try to gather these different strands of evidence together in order to assess the reasons behind the apparent predominance of anthroponotic transmission in Africa. Reviewing the available evidence provides an opportunity to re-think transmission pathways, not only in Africa but also elsewhere, and also to pose questions. Does the predominance of human-to-human transmission in Africa reflect a relative absence of zoonotic C. parvum in African livestock? Are Africans less susceptible to zoonotic Cryptosporidium infection, perhaps resulting from early immunostimulation by C. hominis or due to inherent genetic traits? Is the African environment-in all its variety-simply more detrimental to oocyst survival? Will the so-called hypertransmissible subtypes, currently relatively rare in Africa, be introduced from Europe or elsewhere, and, if so, will they fade out or establish and spread? Our intention with this manuscript is not only to summarize and consolidate diverse data, thereby providing an overview of data gaps, but also to provide food for thought regarding transmission of a parasite that continues to have a considerable impact on both human and animal health.

Cryptosporidium and Cryptosporidiosis: The Perspective from the Gulf Countries

The present review discusses the burden of cryptosporidiosis in the Gulf Cooperation Council (GCC), which is underreported and underestimated. It emphasizes that the Cryptosporidium parasite is infecting inhabitants and expatriates in the Gulf countries. Children under 5 years are a vulnerable group that is particularly affected by this parasitic disease and can act as carriers, who contribute to the epidemiology of the disease most probably via recreational swimming pools. Various risk factors for cryptosporidiosis in the GCC countries are present, including expatriates, predisposing populations to the infection. Water contamination, imported food, animal contact, and air transmission are also discussed in detail, to address their significant role as a source of infection and, thus, their impact on disease epidemiology in the Gulf countries' populations.

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

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

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.

Prevalence and Characterization of Cryptosporidium Species and Genotypes in Four Farmed Deer Species in the Northeast of China

Cryptosporidiosis is a major public health problem in humans and animals. Information on the prevalence and molecular diversity of Cryptosporidium in farmed deer in northeastern China is limited. In this study, the prevalence of these parasites was investigated in four farmed deer species, including 125 reindeer, 109 red deer, 86 sika deer, and 18 Siberian roe deer by nested PCR amplification of the partial small subunit of ribosomal RNA (SSU rRNA) gene. C. ubiquitum isolates were subtyped using nested PCR and sequence analysis of the 60-kDa glycoprotein (gp60) gene. The overall prevalence of Cryptosporidium was 7.1%, with 15.1% for sika deer, 4.0% for reindeer, 4.6% for red deer, and 5.6% for roe deer. C. ubiquitum (n = 4), C. xiaoi (n = 2), and Cryptosporidium deer genotype (n = 18) were identified. All four C. ubiquitum isolates belonged to the XIIa subtype (n = 4). This study confirms that Cryptosporidium deer genotype is widely occurring in deer in the investigated areas. Presence of zoonotic C. ubiquitum XIIa subtype indicates that farmed deer represent potential source of zoonotic cryptosporidia and might pose a threat to human health.

Subtyping Cryptosporidium ryanae: A Common Pathogen in Bovine Animals

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

Description of Cryptosporidium ornithophilus n. sp. (Apicomplexa: Cryptosporidiidae) in farmed ostriches

BACKGROUND

Avian cryptosporidiosis is a common parasitic disease that is caused by five species, which are well characterised at the molecular and biological level, and more than 18 genotypes for which we have limited information. In this study, we determined the occurrence and molecular characteristics of Cryptosporidium spp. in farmed ostriches in the Czech Republic.

METHODS

The occurrence and genetic identity of Cryptosporidium spp. were analysed by microscopy and PCR/sequencing of the small subunit rRNA, actin, HSP70 and gp60 genes. Cryptosporidium avian genotype II was examined from naturally and experimentally infected hosts and measured using differential interference contrast. The localisation of the life-cycle stages was studied by electron microscopy and histologically. Infectivity of Cryptosporidium avian genotype II for cockatiels (Nymphicus hollandicus (Kerr)), chickens (Gallus gallus f. domestica (L.)), geese (Anser anser f. domestica (L.)), SCID and BALB/c mice (Mus musculus L.) was verified.

RESULTS

A total of 204 individual faecal samples were examined for Cryptosporidium spp. using differential staining and PCR/sequencing. Phylogenetic analysis of small subunit rRNA, actin, HSP70 and gp60 gene sequences showed the presence of Cryptosporidium avian genotype II (n = 7) and C. ubiquitum Fayer, Santín & Macarisin, 2010 IXa (n = 5). Only ostriches infected with Cryptosporidium avian genotype II shed oocysts that were detectable by microscopy. Oocysts were purified from a pooled sample of four birds, characterised morphometrically and used in experimental infections to determine biological characteristics. Oocysts of Cryptosporidium avian genotype II measure on average 6.13 × 5.15 μm, and are indistinguishable by size from C. baileyi Current, Upton & Haynes, 1986 and C. avium Holubová, Sak, Horčičková, Hlásková, Květoňová, Menchaca, McEvoy & Kváč, 2016. Cryptosporidium avian genotype II was experimentally infectious for geese, chickens and cockatiels, with a prepatent period of four, seven and eight days post-infection, respectively. The infection intensity ranged from 1000 to 16,000 oocysts per gram. None of the naturally or experimentally infected birds developed clinical signs in the present study.

CONCLUSIONS

The molecular and biological characteristics of Cryptosporidium avian genotype II, described here, support the establishment of a new species, Cryptosporidium ornithophilus n. sp.

Molecular identification of Cryptosporidium isolates from ill exotic pet animals in Japan including a new subtype in Cryptosporidium fayeri

Cryptosporidium is an obligate intracellular parasite which can cause fatal diarrheal disease in exotic animals. Sugar gliders (Petaurus breviceps), hedgehogs (Atelerix albiventris), chinchillas (Chinchilla lanigera), and common leopard geckos (Eublepharis macularius) are popular exotic animals commonly sold in pet shops in Japan. We herein investigated the species and subtypes of Cryptosporidium in these animals. Cryptosporidium fayeri was detected in a sugar glider in a Japanese animal hospital. Sequence analyses of the 60-kDa glycoprotein (gp60) gene revealed that C. fayeri belonged to subtype family IVh (IVhA13G2T1), which was proposed to be a new subtype. This is the first study to report C. fayeri infection in a sugar glider. In other animals, the Cryptosporidium horse genotype, C. ubiquitum, and C. varanii were detected in two four-toed hedgehogs (A. albiventris), a chinchilla (C. lanigera), and common leopard gecko (E. macularius), respectively. The gp60 subtypes identified were VIbA13 of the horse genotype and XIId of C. ubiquitum. The present results revealed that potentially zoonotic Cryptosporidium is widespread in exotic animals in Japan.

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Cryptosporidium was detected from ill exotic pet animals in Japan.

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Cryptosporidium fayeri was detected for the first time from a sugar glider.

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The new 60-kDa glycoprotein (gp60) subtype family IVh was detected from Cryptosporidium fayeri.

Molecular identification of Cryptosporidium spp. in alpacas (Vicugna pacos) in China

Cryptosporidium is a ubiquitous protozoan in human and animals. To investigate the genetic diversity of Cryptosporidium spp. in alpaca (Vicugna pacos) in China, 484 fecal samples from alpacas were collected at nine sites, and Cryptosporidium spp. were screened with PCR amplification of the small subunit ribosome RNA (SSU rRNA) locus. Cryptosporidium spp. infected 2.9% (14/484) of the alpacas. Of the nine collection sites, two were positive for Cryptosporidium, Wensu (3.0%, 3/100) and Qinghe (31.4%, 11/35). Three Cryptosporidium species were identified: C. parvum (n = 2), C. ubiquitum (n = 1), and C. occultus (n = 11). Cryptosporidium parvum and C. ubiquitum were further subtyped with the 60-kDa glycoprotein locus (gp60). The two C. parvum isolates were subtype IIdA15G1, but the one C. ubiquitum isolate was not subtyped successfully. A phylogenetic analysis indicated that the Cryptosporidium isolates clustered with previously identified species. To our knowledge, this is the first report of Cryptosporidium infections in alpacas in China and provides baseline data for the study of Cryptosporidium in alpacas in China.

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First report of Cryptosporidium spp. infections (with 2.9%) in alpacas in China.

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Three zoonotic Cryptosporidium species were identified in alpacas.

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It provides the molecular characteristic data for the study of Cryptosporidium in alpacas.

Prevalence and molecular characterization of Cryptosporidium spp. in Père David's deer (Elaphurus davidianus) in Jiangsu, China

Cryptosporidium is a zoonotic parasite that causes diarrhea in a broad range of animals, including deer. Little is known about the prevalence and genotype of Cryptosporidium spp. in Père David's deer. In this study, 137 fecal samples from Père David's deer were collected between July 2017 and August 2018 in the Dafeng Reserve and analyzed for Cryptosporidium spp. by nested-PCR based on the small subunit ribosomal RNA (SSU rRNA) gene, followed by sequence analyses to determine the species. The 60 kDa glycoprotein (gp60) gene was used to characterize Cryptosporidium spp. Among 137 samples, 2 (1.46%) were positive for Cryptosporidium spp. according to SSU rRNA gene sequencing results. Both samples belonged to the Cryptosporidium deer genotype, with two nucleotide deletions and one nucleotide substitution. The prevalence data and molecular characterization of this study provide basic knowledge for controlling and preventing Cryptosporidium infections in Père David's deer in this area.

Molecular characterization of Cryptosporidium spp. and Giardia duodenalis in experimental rats in China

Cryptosporidium and Giardia are ubiquitous protozoan parasites that infect a broad range of hosts. The presence of Cryptosporidium spp. and G. duodenalis was detected in 355 fecal samples of laboratory experimental rats from four experimental rat rearing facilities in China by PCR amplification of the small subunit (SSU) rRNA gene. The G. duodenalis positive samples were further characterized in the β-giardin (bg), glutamate dehydrogenase (gdh), and triosephosphate isomerase (tpi) genes. The overall infection rates of Cryptosporidium spp. and G. duodenalis were 0.6% (2/355) and 9.3% (33/355), respectively, with no co-infection. Among the four facilities, only the rats in Zhengzhou1 were found positive for the two pathogens. Undetermined Cryptosporidium genotype was observed in one sample and C. ubiquitum in another sample. Assemblage G was identified in all the 33 G. duodenalis positive isolates at SSU rRNA gene, out of which 19, 20, and 21 isolates were also subtyped as assemblage G at tpi, gdh and bg gens, respectively. To our knowledge, this is the first report of Cryptosporidium and G. duodenalis infections in laboratory experimental rats in China. The infections of these pathogens in laboratory animals should be monitored routinely since they may interfere the biological experiments in these animals.

Cryptosporidium and Giardia in Ruminants

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

Common occurrence of divergent Cryptosporidium species and Cryptosporidium parvum subtypes in farmed bamboo rats (Rhizomys sinensis)

BACKGROUND

Bamboo rats are widely farmed in southern China for meat, but their potential in transmitting pathogens to humans and other farm animals remains unclear.

METHODS

To understand the transmission of Cryptosporidium spp. in these animals, 709 fecal samples were collected in this study from Chinese bamboo rats (Rhizomys sinensis) on nine farms in Jiangxi, Guangxi and Hainan provinces, China. They were analyzed for Cryptosporidium spp. using PCR and sequence analyses of the small subunit rRNA gene. Cryptosporidium parvum, C. parvum-like and C. ubiquitum-like genotypes identified were subtyped by sequence analysis of the 60 kDa glycoprotein (gp60) gene.

RESULTS

Altogether, Cryptosporidium spp. were detected in 209 (29.5%) samples. The detection rate in samples from animals under two months of age (70.0%,105/150) was significantly higher than in samples from animals above 2 months (18.6%, 104/559; χ² = 150.27, df = 1, P < 0.0001). Four Cryptosporidium species/genotypes were identified: C. parvum (n = 78); C. occultus (n = 1); a new genotype that is genetically related to C. ubiquitum (n = 85); and another new genotype that is genetically related to C. parvum (n = 44). Among them, C. parvum (27,610 ± 71,911 oocysts/gram of feces) and the C. parvum-like genotype (38,679 ± 82,811 oocysts/gram of feces) had higher oocyst shedding intensity than the C. ubiquitum-like genotype (2470 ± 7017 oocysts/gram of feces) and the C. occultus (1012 oocysts/gram of feces). The C. parvum identified belonged to three subtypes in two rare subtype families, including IIpA9 (n = 43), IIpA6 (n = 6) and IIoA15G1 (n = 9), while the C. parvum-like and C. ubiquitum-like genotypes generated very divergent gp60 sequences.

CONCLUSIONS

Results of the present study suggest that bamboo rats on the study farms were infected with diverse Cryptosporidium species and divergent C. parvum subtypes, which probably had originated from their native habitats. As similar C. parvum subtypes have been recently detected in humans and farmed macaques, attentions should be paid to the potential role of these new farm animals in the transmission of zoonotic pathogens.

Development of a gp60-subtyping method for Cryptosporidium felis

BACKGROUND

Feline cryptosporidiosis is an increasing problem, especially in catteries. In humans, close contact with cats could be a potential source of infection although the risk of contracting cryptosporidiosis caused by Cryptosporidium felis is considered to be relatively low. Sequencing of the 60-kDa glycoprotein gene is a commonly used tool for investigation of the genetic diversity and transmission dynamics of Cryptosporidium species. However, until now the sequence of gp60 from C. felis has not been available and genotyping has been limited to less discriminatory markers, such as 18S rRNA, COWP and HSP70.

METHODS

We have identified the gp60 orthologue within the genome sequence of C. felis, and used the sequence to design a nested PCR for subtyping purposes. A total of 128 clinical isolates of both feline and human origin, were used to evaluate the marker.

RESULTS

Sequence analysis revealed large variations between the different samples. The C. felis gp60 lack the characteristic serine-tract found in many other cryptosporidian orthologues, instead it has an insertion of variable length (361-742 nt). Also, two cases of suspected zoonotic transmission of C. felis between cats and humans were successfully confirmed.

CONCLUSIONS

We have identified the gp60 gene in C. felis and show how this highly variable marker can be used in epidemiological investigations.

Prevalence and molecular characterization of Cryptosporidium species in poultry in Bangladesh

Cryptosporidium is an opportunistic parasite that has been reported in >30 avian hosts worldwide, however, there is no information regarding Cryptosporidium spp. in poultry in Bangladesh. Accordingly, we investigated the prevalence of Cryptosporidium spp. in poultry at open live bird markets in Bangladesh. A total of 197 samples were randomly collected from poultry at open live bird markets in Bangladesh and screened for the detection of Cryptosporidium. Initial microscopic examination revealed Cryptosporidium spp. was observed in 19.8% (39/197) of the poultry specimens. Subsequent nested PCR targeting the 18S rRNA gene revealed that 15.7% (31/197) of the samples were Cryptosporidium positive. Of these 31 samples, 17 were Cryptosporidium baileyi (8.7%), 12 were Cryptosporidium meleagridis (6.0%), and 2 were Cryptosporidium parvum (1.0%). Nucleotide sequence analysis of the GP60 gene of the C. meleagridis revealed that two subtypes (IIIbA21G1R1 and IIIbA23G1R1), which were found in broiler, native and sonali chickens and a pigeon, matched those previously reported in humans and poultry. We identified two novel subtypes (IIIbA21G2R1 and IIIbA20G2R1) in sonali chickens, a broiler chicken and a layer chicken. We also amplified the GP60 gene of C. parvum and found two subtypes (IIaA11G2R1 and IIaA13G2R1) in a sonali and a broiler chicken that were previously reported in calf. These findings suggest that poultry can be a source of cryptosporidial infections for humans and animals in Bangladesh. This is the first molecular investigation of Cryptosporidium genotypes and subtypes in poultry at open live bird markets in Bangladesh.

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Cryptosporidium genotypes and subtypes in poultry in Bangladesh have been investigated firstly.

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Cryptosporidium baileyi, C. meleagridis and C. parvum are identified while C. baileyi is predominant species in poultry.

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Two novel subtypes (IIIbA21G2R1 and IIIbA20G2R1) of the C. meleagridis in chickens are detected.

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Cryptosporidium parasites are common among the live bird markets in Bangladesh.

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

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

Direct Sequencing of Cryptosporidium in Stool Samples for Public Health

The protozoan parasite Cryptosporidium is an important cause of diarrheal disease (cryptosporidiosis) in humans and animals, with significant morbidity and mortality especially in severely immunocompromised people and in young children in low-resource settings. Due to the sexual life cycle of the parasite, transmission is complex. There are no restrictions on sexual recombination between sub-populations, meaning that large-scale genetic recombination may occur within a host, potentially confounding epidemiological analysis. To clarify the relationships between infections in different hosts, it is first necessary to correctly identify species and genotypes, but these differentiations are not made by standard diagnostic tests and more sophisticated molecular methods have been developed. For instance, multilocus genotyping has been utilized to differentiate isolates within the major human pathogens, Cryptosporidium parvum and Cryptosporidium hominis. This has allowed mixed populations with multiple alleles to be identified: recombination events are considered to be the driving force of increased variation and the emergence of new subtypes. As yet, whole genome sequencing (WGS) is having limited impact on public health investigations, due in part to insufficient numbers of oocysts and purity of DNA derived from clinical samples. Moreover, because public health agencies have not prioritized parasites, validation has not been performed on user-friendly data analysis pipelines suitable for public health practitioners. Nonetheless, since the first whole genome assembly in 2004 there are now numerous genomes of human and animal-derived cryptosporidia publically available, spanning nine species. It has also been demonstrated that WGS from very low numbers of oocysts is possible, through the use of amplification procedures. These data and approaches are providing new insights into host-adapted infectivity, the presence and frequency of multiple sub-populations of Cryptosporidium spp. within single clinical samples, and transmission of infection. Analyses show that although whole genome sequences do indeed contain many alleles, they are invariably dominated by a single highly abundant allele. These insights are helping to better understand population structures within hosts, which will be important to develop novel prevention strategies in the fight against cryptosporidiosis.

Prevalence and genotyping identification of Cryptosporidium in adult ruminants in central Iran

Background

Apicomplexan parasites of the genus Cryptosporidium infect a wide range of animal species as well as humans. Cryptosporidium spp. can cause life threatening diarrhea especially in young animals, children, immunocompromised patients and malnourished individuals. Asymptomatic cryptosporidial infections in animals can also occur, making these animals potential reservoirs of infection.

Methods

In the present study, a molecular survey of Cryptosporidium spp. in ruminants that were slaughtered for human consumption in Yazd Province, located in central Iran was conducted. Faeces were collected per-rectum from 484 animals including 192 cattle, 192 sheep and 100 goats. DNA was extracted from all samples and screened for Cryptosporidium by PCR amplification of the 18S rRNA gene. Positives were Sanger sequenced and further subtyped by sequence analysis of the 60 kDa glycoprotein (gp60) locus.

Results

In total, Cryptosporidium spp. were detected in 22 animals: C. andersoni and C. bovis in seven and two cattle faecal samples, respectively, C. ubiquitum in five sheep, and C. xiaoi in six sheep and two goat samples, respectively. To our knowledge, this study provides for the first time, molecular information concerning Cryptosporidium species infecting goats in Iran, and is also the first report of C. ubiquitum and C. xiaoi from ruminants in Iran.

Conclusion

The presence of potentially zoonotic species of Cryptosporidium in ruminants in this region may suggest that livestock could potentially contribute to human cryptosporidiosis, in particular among farmers and slaughterhouse workers, in the area. Further molecular studies on local human populations are required to more accurately understand the epidemiology and transmission dynamics of Cryptosporidium spp. in this region.

Cryptosporidium parvum and Cryptosporidium hominis subtypes in crab-eating macaques

BACKGROUND

Non-human primates are often infected with human-pathogenic Cryptosporidium hominis subtypes, but rarely with Cryptosporidium parvum. In this study, 1452 fecal specimens were collected from farmed crab-eating macaques (Macaca fascicularis) in Hainan, China during the period April 2016 to January 2018. These specimens were analyzed for Cryptosporidium species and subtypes by using PCR and sequence analysis of the 18S rRNA and 60 kDa glycoprotein (gp60) genes, respectively.

RESULTS

Altogether, Cryptosporidium was detected using 18S rRNA-based PCR in 132 (9.1%) sampled animals, with significantly higher prevalence in females (12.5% or 75/599 versus 6.1% or 43/706), younger animals (10.7% or 118/1102 in monkeys 1-3-years-old versus 4.0% or 14/350 in those over 3-years-old) and animals with diarrhea (12.6% or 46/365 versus 7.9% or 86/1087). Four Cryptosporidium species were identified, namely C. hominis, C. parvum, Cryptosporidium muris and Cryptosporidium ubiquitum in 86, 30, 15 and 1 animal, respectively. The identified C. parvum, C. hominis and C. ubiquitum were further subtyped by using gp60 PCR. Among them, C. parvum belonged to subtypes in two known subtype families, namely IIoA14G1 (in 18 animals) and IIdA19G1 (in 2 animals). In contrast, C. hominis mostly belonged to two new subtype families Im and In, which are genetically related to Ia and Id, respectively. The C. hominis subtypes identified included ImA18 (in 38 animals), InA14 (in six animals), InA26 (in six animals), InA17 (in one animal) and IiA17 (in three animals). The C. ubiquitum isolates belonged to subtype family XIId. By subtype, ImA18 and IIoA14G1 were detected in animals with diarrhea whereas the remaining ones were mostly found in asymptomatic animals. Compared with C. parvum and C. muris, higher oocyst shedding intensity was observed in animals infected with C. hominis, especially those infected with the Im subtype family.

CONCLUSIONS

Data from the study suggest that crab-eating macaques are infected with diverse C. parvum and C. hominis subtypes. The C. parvum IIo subtype family previously seen in rodents in China has apparently expanded its host range.

Comparative analysis reveals conservation in genome organization among intestinal Cryptosporidium species and sequence divergence in potential secreted pathogenesis determinants among major human-infecting species

Background

Cryptosporidiosis is a major cause of gastrointestinal diseases in humans and other vertebrates. Previous analyses of invasion-related proteins revealed that Cryptosporidium parvum, Cryptosporidium hominis, and Cryptosporidium ubiquitum mainly differed in copy numbers of secreted MEDLE proteins and insulinase-like proteases and sequences of mucin-type glycoproteins. Recently, Cryptosporidium chipmunk genotype I was identified as a novel zoonotic pathogen in humans. In this study, we sequenced its genome and conducted a comparative genomic analysis.

Results

The genome of Cryptosporidium chipmunk genotype I has gene content and organization similar to C. parvum and other intestinal Cryptosporidium species sequenced to date. A total of 3783 putative protein-encoding genes were identified in the genome, 3525 of which are shared by Cryptosporidium chipmunk genotype I and three major human-pathogenic Cryptosporidium species, C. parvum, C. hominis, and Cryptosporidium meleagridis. The metabolic pathways are almost identical among these four Cryptosporidium species. Compared with C. parvum, a major reduction in gene content in Cryptosporidium chipmunk genotype I is in the number of telomeric genes encoding MEDLE proteins (two instead of six) and insulinase-like proteases (one instead of two). Highly polymorphic genes between the two species are mostly subtelomeric ones encoding secretory proteins, most of which have higher dN/dS ratios and half are members of multiple gene families. In particular, two subtelomeric ABC transporters are under strong positive selection.

Conclusions

Cryptosporidium chipmunk genotype I possesses genome organization, gene content, metabolic pathways and invasion-related proteins similar to the common human-pathogenic Cryptosporidium species, reaffirming its human-pathogenic nature. The loss of some subtelomeric genes encoding insulinase-like proteases and secreted MEDLE proteins and high sequence divergence in secreted pathogenesis determinants could contribute to the biological differences among human-pathogenic Cryptosporidium species.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5788-9) contains supplementary material, which is available to authorized users.

Distribution and molecular characterization of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi amongst grazing adult sheep in Xinjiang, China

To assess the prevalence and molecular characteristics of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in grazing adult sheep from Xinjiang Uygur Autonomous Region, China, 318 fecal samples were collected and screened for the presence of these parasites by polymerase chain reaction. The overall infection rate for the three pathogens was 13.5% (43/318), with observed individual infection rates of 0.9% (3/318), 7.5% (24/318), and 6.3% (20/318) for Cryptosporidium spp., G. duodenalis, and E. bieneusi, respectively. Three Cryptosporidium species were identified amongst the samples, including C. xiaoi (n = 1), C. ubiquitum (n = 1), and C. parvum (n = 1), with gp60-based subtyping analysis identifying C. parvum as subtype IIdA15G1 and C. ubiquitum as subtype XIIa. Eight E. bieneusi genotypes were identified based on internal transcribed spacer region sequencing, including six known (BEB6, CHG1, CHG3, CHS3, CHS8, and COS-I) and two novel (designated XJS1 and XJS2) genotypes. All G. duodenalis-positive samples were identified as assemblage E based on small subunit rRNA (n = 24) and gdh (n = 10) gene sequence analysis. These data support the occurrence of host adaptation by Cryptosporidium spp., G. duodenalis, and E. bieneusi in sheep, and the zoonotic risk may posed by these parasites in Xinjiang, China.

Diversity of Cryptosporidium spp. in Apodemus spp. in Europe

The genetic diversity of Cryptosporidium spp. in Apodemus spp. (striped field mouse, yellow-necked mouse and wood mouse) from 16 European countries was examined by PCR/sequencing of isolates from 437 animals. Overall, 13.7% (60/437) of animals were positive for Cryptosporidium by PCR. Phylogenetic analysis of small-subunit rRNA, Cryptosporidium oocyst wall protein and actin gene sequences showed the presence of Cryptosporidium ditrichi (22/60), Cryptosporidium apodemi (13/60), Cryptosporidium apodemus genotype I (8/60), Cryptosporidium apodemus genotype II (9/60), Cryptosporidium parvum (2/60), Cryptosporidium microti (2/60), Cryptosporidium muris (2/60) and Cryptosporidium tyzzeri (2/60). At the gp60 locus, novel gp60 families XVIIa and XVIIIa were identified in Cryptosporidium apodemus genotype I and II, respectively, subtype IIaA16G1R1b was identified in C. parvum, and subtypes IXaA8 and IXcA6 in C. tyzzeri. Only animals infected with C. ditrichi, C. apodemi, and Cryptosporidium apodemus genotypes shed oocysts that were detectable by microscopy, with the infection intensity ranging from 2000 to 52,000 oocysts per gram of faeces. None of the faecal samples was diarrheic in the time of the sampling.

Profiling the diversity of Cryptosporidium species and genotypes in wastewater treatment plants in Australia using next generation sequencing

Wastewater recycling is an increasingly popular option in worldwide to reduce pressure on water supplies due to population growth and climate change. Cryptosporidium spp. are among the most common parasites found in wastewater and understanding the prevalence of human-infectious species is essential for accurate quantitative microbial risk assessment (QMRA) and cost-effective management of wastewater. The present study conducted next generation sequencing (NGS) to determine the prevalence and diversity of Cryptosporidium species in 730 raw influent samples from 25 Australian wastewater treatment plants (WWTPs) across three states: New South Wales (NSW), Queensland (QLD) and Western Australia (WA), between 2014 and 2015. All samples were screened for the presence of Cryptosporidium at the 18S rRNA (18S) locus using quantitative PCR (qPCR), oocyst numbers were determined directly from the qPCR data using DNA standards calibrated by droplet digital PCR, and positives were characterized using NGS of 18S amplicons. Positives were also screened using C. parvum and C. hominis specific qPCRs. The overall Cryptosporidium prevalence was 11.4% (83/730): 14.3% (3/21) in NSW; 10.8% (51/470) in QLD; and 12.1% (29/239) in WA. A total of 17 Cryptosporidium species and six genotypes were detected by NGS. In NSW, C. hominis and Cryptosporidium rat genotype III were the most prevalent species (9.5% each). In QLD, C. galli, C. muris and C. parvum were the three most prevalent species (7.7%, 5.7%, and 4.5%, respectively), while in WA, C. meleagridis was the most prevalent species (6.3%). The oocyst load/Litre ranged from 70 to 18,055 oocysts/L (overall mean of 3426 oocysts/L: 4746 oocysts/L in NSW; 3578 oocysts/L in QLD; and 3292 oocysts/L in WA). NGS-based profiling demonstrated that Cryptosporidium is prevalent in the raw influent across Australia and revealed a large diversity of Cryptosporidium species and genotypes, which indicates the potential contribution of livestock, wildlife and birds to wastewater contamination.

Zoonotic Cryptosporidium species and subtypes in lambs and goat kids in Algeria

BACKGROUND

Little is known on the occurrence and identity of Cryptosporidium species in sheep and goats in Algeria. This study aimed at investigating the occurrence of Cryptosporidium species in lambs and goat kids younger than 4 weeks.

METHODS

A total of 154 fecal samples (62 from lambs and 92 from kid goats) were collected from 13 sheep flocks in Médea, Algeria and 18 goat flocks across Algiers and Boumerdes. They were screened for Cryptosporidium spp. by nested-PCR analysis of a fragment of the small subunit (SSU) rRNA gene, followed by restriction fragment length polymorphism and sequence analyses to determine the Cryptosporidium species present. Cryptosporidium parvum and C. ubiquitum were further subtyped by sequence analysis of the 60 kDa glycoprotein gene.

RESULTS

Cryptosporidium spp. were detected in 17 fecal samples (11.0%): 9 from lambs (14.5%) and 8 from goat kids (8.7%). The species identified included C. parvum in 3 lambs, C. xiaoi in 6 lambs and 6 goat kids, and C. ubiquitum in 2 goat kids. Cryptosporidium infections were detected mostly in animals during the first two weeks of life (7/8 for goat kids and 7/9 for lambs) and in association with diarrhea occurrence (7/17 or 41.2% goat kids and 7/10 or 70.0% lambs with diarrhea were positive for Cryptosporidium spp.). Subtyping of C. parvum and C. ubiquitum isolates identified the zoonotic IIaA13G2R1 and XIIa subtype families, respectively. Minor differences in the SSU rRNA gene sequences were observed between C. xiaoi from sheep and goats.

CONCLUSIONS

Results of this study indicate that three Cryptosporidium species occur in lambs and goat kids in Algeria, including zoonotic C. parvum and C. ubiquitum. They are associated with the occurrence of neonatal diarrhea.

Molecular and histopathological features of Cryptosporidium ubiquitum infection in imported chinchillas Chinchilla lanigera in Japan

Long-tailed chinchillas Chinchilla lanigera are popular rodent species kept both in households, where they are hand-raised as pets, and in zoological facilities. From January 2016 to February 2017, 13 juvenile chinchillas from five facilities in Japan were diagnosed with cryptosporidiosis at the animal hospital. Eight of the cases were fatal. All of the animals were imported from the Czech Republic by the same vendor. Histopathological and multilocus sequence analyses using 18S ribosomal RNA, actin, 70-kDa heat shock protein, and 60-kDa glycoprotein genes confirmed Cryptosporidium ubiquitum of subtype XIId as the etiological agent. Multilocus analysis demonstrated the presence of two new sequence types closely related to the C. ubiquitum Xlld strain isolated from a human in the USA. This study indicated that potentially zoonotic Cryptosporidium is widespread and may have caused a high number of deaths among imported juvenile chinchillas.

Sheep as a Potential Source of Zoonotic Cryptosporidiosis in China

In this study, we assessed the prevalence and genetic characteristics of Cryptosporidium in sheep from 10 provinces in China. Fecal samples from 1,035 sheep originating from 16 farms were collected, and 295 (28.5%) were found to be Cryptosporidium positive by nested PCR. Cryptosporidium was detected at all farms, with infection rates between 5.7% and 50.0%. Three Cryptosporidium species were identified, including Cryptosporidium xiaoi (73.2%, 216/295), Cryptosporidium ubiquitum (21.7%, 64/295), and Cryptosporidium parvum (5.1%, 15/295). The distribution of Cryptosporidium species differed by province and by farm. All three species were detected in lambs and adult sheep but the highest infection rate was found in postweaned lambs. All three species were detected in all four seasons, with the highest prevalence found in autumn. Four C. parvum subtypes (IIaA15G2R1, IIaA17G2R1, IIdA18G1, and IIdA19G1) and one C. ubiquitum subtype (XIIa) were identified. For most provinces in this study, we are not aware of a previously published description or molecular characterization of Cryptosporidium infections in sheep. This information will improve our knowledge and understanding of the epidemiology of cryptosporidiosis in China.IMPORTANCECryptosporidium is an important zoonotic parasite that causes diarrhea in humans and animals worldwide. Previous studies suggested geographic differences in the distribution of Cryptosporidium species in sheep. However, molecular characterization studies of Cryptosporidium species in sheep have been carried out in only a few provinces in China, and the limited data available do not reflect the real situation. In this study, five districts, covering most areas where sheep are bred in China, were selected for examination of Cryptosporidium species, and Cryptosporidium infections were detected at all farms assessed, suggesting that Cryptosporidium is widespread in sheep in China. We also found geographic differences in the distribution of Cryptosporidium species but did not detect any differences between sheep age groups or seasons. Subtyping analyses showed that all of the subtypes identified in this study have been reported in humans, suggesting that sheep may be a potential source of zoonotic cryptosporidiosis.

First cross-sectional, molecular epidemiological survey of Cryptosporidium, Giardia and Enterocytozoon in alpaca (Vicugna pacos) in Australia

BACKGROUND

Eukaryotic pathogens, including Cryptosporidium, Giardia and Enterocytozoon, have been implicated in neonatal diarrhoea, leading to marked morbidity and mortality in the alpaca (Vicugna pacos) and llama (Lama glama) around the world. Australia has the largest population of alpacas outside of South America, but very little is known about these pathogens in alpaca populations in this country. Here, we undertook the first molecular epidemiological survey of Cryptosporidium, Giardia and Enterocytozoon in V. pacos in Australia.

METHODS

A cross-sectional survey of 81 herds, comprising alpacas of 6 weeks to 26 years of age, were sampled from the six Australian states (Queensland, New South Wales, Victoria, South Australia, Tasmania and Western Australia) across the four seasons. PCR-based sequencing was employed, utilising genetic markers in the small subunit of the nuclear ribosomal RNA (SSU) and 60-kilodalton glycoprotein (gp60) genes for Cryptosporidium, triose-phosphate isomerase (tpi) gene for Giardia duodenalis and the internal transcribed spacer region (ITS) for Enterocytozoon bieneusi.

RESULTS

PCR-based analyses of 81 faecal DNA samples representing 1421 alpaca individuals detected Cryptosporidium, Giardia and/or Enterocytozoon on 15 farms in New South Wales, Victoria and South Australia, equating to 18.5% of all samples/herds tested. Cryptosporidium was detected on three (3.7%) farms, G. duodenalis on six (7.4%) and E. bieneusi on eight (9.9%) in two or all of these three states, but not in Queensland, Tasmania or Western Australia. Molecular analyses of selected faecal DNA samples from individual alpacas for Cryptosporidium, Giardia and/or Enterocytozoon consistently showed that alpacas of ≤ 6 months of age harboured these pathogens.

CONCLUSIONS

This first molecular investigation of Cryptosporidium, Giardia and Enterocytozoon in alpaca subpopulations in Australia has identified species and genotypes that are of likely importance as primary pathogens of alpacas, particularly young crias, and some genotypes with zoonotic potential. Although the prevalence established here in the alpaca subpopulations studied is low, the present findings suggest that crias are likely reservoirs of infections to susceptible alpacas and/or humans. Future studies should focus on investigating pre-weaned and post-weaned crias, and on exploring transmission patterns to establish what role particular genotypes play in neonatal or perinatal diarrhoea in alpacas and in zoonotic diseases in different states of Australia.

Genomics and molecular epidemiology of Cryptosporidium species

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

Diversity of Cryptosporidium in common voles and description of Cryptosporidium alticolis sp. n. and Cryptosporidium microti sp. n. (Apicomplexa: Cryptosporidiidae)

Fecal samples from wild-caught common voles (n = 328) from 16 locations in the Czech Republic were screened for Cryptosporidium by microscopy and PCR/sequencing at loci coding small-subunit rRNA, Cryptosporidium oocyst wall protein, actin and 70 kDa heat shock protein. Cryptosporidium infections were detected in 74 voles (22.6%). Rates of infection did not differ between males and females nor between juveniles and adults. Phylogenetic analysis revealed the presence of eight Cryptosporidium species/genotypes including two new species, C. alticolis and C. microti. These species from wild-caught common voles were able to infect common and meadow voles under experimental conditions, with a prepatent period of 3-5 days post-infection (DPI), but they were not infectious for various other rodents or chickens. Meadow voles lost infection earlier than common voles (11-14 vs 13-16 DPI) and had significantly lower infection intensity. Cryptosporidium alticolis infects the anterior small intestine and has larger oocysts (5.4 × 4.9 µm), whereas C. microti infects the large intestine and has smaller oocysts (4.3 × 4.1 µm). None of the rodents developed clinical signs of infection. Genetic and biological data support the establishment of C. alticolis and C. microti as separate species of the genus Cryptosporidium.

Cryptosporidium infection is associated with reduced growth and diarrhoea in goats beyond weaning

Cryptosporidium and Giardia are common parasites of ruminant livestock worldwide. These parasites are associated with diarrhoea outbreaks in young goats (pre-weaning), but the impacts on health and productivity for older goats (post-weaning) are not well understood. Here we show Cryptosporidium faecal shedding is associated with reduced growth and diarrhoea in goats aged approximately 9-15 months. Goats were sampled four times at one-month intervals. Faecal shedding for a range of pathogens were determined using quantitative PCR and sequencing (Cryptosporidium, Giardia, Eimeria, Salmonella, Campylobacter), and microscopy (trichostrongylid nematode worm egg count and Entamoeba). Cryptosporidium faecal shedding was associated with 1.5 kg lower growth for the one-month period following sampling. Specifically, C. xiaoi was associated with 1.9 kg lower growth in the following month. This is the first report of production impacts associated with C. xiaoi in ruminants older than 3 months of age. Cryptosporidium shedding was associated with an over 4-fold increase in risk of diarrhoea, with C. parvum associated with 10-fold and C. ubiquitum associated with 16-fold increase in risk of diarrhoea. Notably, C. xiaoi shedding was not associated with increased risk of diarrhoea. Giardia shedding was associated with looser faecal consistency, but not diarrhoea. Higher Eimeria oocyst counts were weakly associated with lower live weight, poorer body condition and looser faecal consistency. Shedding of other enteric pathogens were not associated with impacts on live weight, growth or diarrhoea risk. This study challenges the two notions that Cryptosporidium infections only impact health and productivity of goats during the pre-weaning period, and that Cryptosporidium (and specifically C. xiaoi) infections in the absence of diarrhoea are asymptomatic. Recognising the potential for impacts of Cryptosporidium infection on growth rates in the absence of diarrhoea will support improved design for experiments testing impacts of Cryptosporidium on ruminant health and production. Improved understanding of the role of protozoan infections on animal health has implications for the management of goats in order to reduce adverse impacts on farm profitability, animal welfare and public health risk.

Understanding human infectious Cryptosporidium risk in drinking water supply catchments

Treating drinking water appropriately depends, in part, on the robustness of source water quality risk assessments, however quantifying the proportion of infectious, human pathogenic Cryptosporidium oocysts remains a significant challenge. We analysed 962 source water samples across nine locations to profile the occurrence, rate and timing of infectious, human pathogenic Cryptosporidium in surface waters entering drinking water reservoirs during rainfall-runoff conditions. At the catchment level, average infectivity over the four-year study period reached 18%; however, most locations averaged <5%. The maximum recorded infectivity fraction within a single rainfall runoff event was 65.4%, and was dominated by C. parvum. Twenty-two Cryptosporidium species and genotypes were identified using PCR-based molecular techniques; the most common being C. parvum, detected in 23% of water samples. Associations between landuse and livestock stocking characteristics with Cryptosporidium were determined using a linear mixed-effects model. The concentration of pathogens in water were significantly influenced by flow and dominance of land-use by commercial grazing properties (as opposed to lifestyle properties) in the catchment (p < 0.01). Inclusion of measured infectivity and human pathogenicity data into a quantitative microbial risk assessment (QMRA) could reduce the source water treatment requirements by up to 2.67 log removal values, depending on the catchment, and demonstrated the potential benefit of collating such data for QMRAs.

Usefulness of Sunlight and Artificial UV Radiation Versus Chlorine for the Inactivation of Cryptosporidium Oocysts: An in Vivo Animal Study

BACKGROUND

Cryptosporidium is an important waterborne protozoan.

AIM

The aim of this study was to investigate the effect of sunlight being the natural source of UV and artificial UV irradiation on Cryptosporidium oocysts versus the effect of chlorination, being the traditional method of water disinfection and to provide an insight into the viability and degree of infectivity of Cryptosporidium oocysts, using an animal model.

METHODS

An experimental study including 300 neonatal mice was carried out to investigate the effect of artificial ultraviolet (UV) irradiation and sunlight being the natural source of UV irradiation versus chlorine, the traditionally used water disinfectant on the infectivity of Cryptosporidium oocysts present in water. For each item, nine different exposure times were investigated. Parasitological assessment (Modified Ziehl Neelsen stained stool smears) and histopathological assessment of the excised segments of the small intestine (stained by both Haematoxylin & Eosin and ZN stain) of mice were used to verify the inactivation of oocysts.

RESULTS

Cryptosporidium oocysts failed to induce any noticeable infection after 4 hours of artificial UV exposure that provided a UV dose of 10mJ/cm2 and after an 8 hours exposure to sunlight, whereas they showed resistance to disinfection by chlorine.

CONCLUSION

The results of the study demonstrate the important role of an 8 hours sunlight exposure of potable water in plastic bottles in achieving complete inactivation of any contaminating Cryptosporidium oocysts, thus offering an applicable, economical and convenient method for the control of cryptosporidiosis especially in developing countries.

Cryptosporidium species and subtypes in animals inhabiting drinking water catchments in three states across Australia

As part of long-term monitoring of Cryptosporidium in water catchments serving Western Australia, New South Wales (Sydney) and Queensland, Australia, we characterised Cryptosporidium in a total of 5774 faecal samples from 17 known host species and 7 unknown bird samples, in 11 water catchment areas over a period of 30 months (July 2013 to December 2015). All samples were initially screened for Cryptosporidium spp. at the 18S rRNA locus using a quantitative PCR (qPCR). Positives samples were then typed by sequence analysis of an 825 bp fragment of the 18S gene and subtyped at the glycoprotein 60 (gp60) locus (832 bp). The overall prevalence of Cryptosporidium across the various hosts sampled was 18.3% (1054/5774; 95% CI, 17.3-19.3). Of these, 873 samples produced clean Sanger sequencing chromatograms, and the remaining 181 samples, which initially produced chromatograms suggesting the presence of multiple different sequences, were re-analysed by Next- Generation Sequencing (NGS) to resolve the presence of Cryptosporidium and the species composition of potential mixed infections. The overall prevalence of confirmed mixed infection was 1.7% (98/5774), and in the remaining 83 samples, NGS only detected one species of Cryptosporidium. Of the 17 Cryptosporidium species and four genotypes detected (Sanger sequencing combined with NGS), 13 are capable of infecting humans; C. parvum, C. hominis, C. ubiquitum, C. cuniculus, C. meleagridis, C. canis, C. felis, C. muris, C. suis, C. scrofarum, C. bovis, C. erinacei and C. fayeri. Oocyst numbers per gram of faeces (g^-1) were also determined using qPCR, with medians varying from 6021-61,064 across the three states. The significant findings were the detection of C. hominis in cattle and kangaroo faeces and the high prevalence of C. parvum in cattle. In addition, two novel C. fayeri subtypes (IVaA11G3T1 and IVgA10G1T1R1) and one novel C. meleagridis subtype (IIIeA18G2R1) were identified. This is also the first report of C. erinacei in Australia. Future work to monitor the prevalence of Cryptosporidium species and subtypes in animals in these catchments is warranted.

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.

Epidemiological observations on cryptosporidiosis and molecular characterization of Cryptosporidium spp. in sheep and goats in Kuwait

Molecular epidemiological analysis of cryptosporidiosis in Middle Eastern countries suggests that small ruminants could play a major role in the transmission of Cryptosporidium spp. to humans, with a dominance of Cryptosporidium parvum, especially its IId subtypes. However, little information is available on the epidemiology and risk factors of cryptosporidiosis as well the distribution of Cryptosporidium species/genotypes and subtypes in small ruminants in this area, including Kuwait. In the present study, 47 farms from several areas in Kuwait were visited once during October 2014 to September 2015 to collect data on risk factors associated with Cryptosporidium infection. Fecal samples from 334 sheep and 222 goats were examined for Cryptosporidium oocysts by Ziehl-Neelsen staining (ZN) and antigens by enzymatic immunoassay (EIA). The Cryptosporidium prevalence was higher when samples were examined by EIA than ZN (11.4 and 7.2% in sheep and goats by EIA, compared with 4.2 and 3.6% by ZN, respectively). Young age (less than 3 months) and closed housing system are risk factors of Cryptosporidium infection. A correlation between fecal consistency and the occurrence of Cryptosporidium spp. was observed; non-formed fecal samples were often found positive. Molecular characterization of 30 ovine and caprine samples using PCR-RFLP analysis of the small subunit rRNA gene revealed the presence of C. parvum in 23 samples, Cryptosporidium ubiquitum in five samples, and Cryptosporidium xiaoi in two samples. Sequence analysis of C. parvum at the 60 KDa glycoprotein gene locus identified two subtypes, IIaA15G2R1 and IIdA20G1, with the latter being more common (in 2 and 20 successfully subtyped samples, respectively). Only one subtype of C. ubiquitum (XIIa) was recorded. Cryptosporidiosis in small ruminants apparently poses public health problem in Kuwait.