First report of Cryptosporidium canis in farmed Arctic foxes (Vulpes lagopus) in China

Divergent Cryptosporidium species and host-adapted Cryptosporidium canis subtypes in farmed minks, raccoon dogs and foxes in Shandong, China

Cryptosporidium spp. are common parasitic pathogens causing diarrhea in humans and various animals. Fur animals are widely farmed in Shandong Province, China, but the prevalence and genetic identity of Cryptosporidium spp. in them are unclear. In this study, 1,211 fecal samples were collected from 602 minks, 310 raccoon dogs and 299 foxes on two farms in Shandong and analyzed for Cryptosporidium spp. by nested PCR and sequence analyses of the small subunit rRNA gene. The overall infection rate of Cryptosporidium spp. was 31.5% (381/1,211), with a higher infection rate in raccoon dogs (37.7%, 117/310) than in foxes (32.4%, 97/299) and minks (27.7%, 167/602). By age, the highest infection rates of Cryptosporidium spp. were observed in raccoon dogs of 1-2 months, minks of 5-6 months, and foxes of > 12 months. Three Cryptosporidium species and genotypes were detected, including C. canis (n = 279), C. meleagridis (n = 65) and Cryptosporidium mink genotype (n = 37). Among the three major host species, raccoon dogs were infected with C. canis only (n = 117), while foxes were infected with both C. canis (n = 32) and C. meleagridis (n = 65), and minks with C. canis (n = 130) and Cryptosporidium mink genotype (n = 37). Subtyping of C. canis by sequence analysis of the 60 kDa glycoprotein gene identified eight subtypes. They belonged to two known subtype families, XXa and XXd, and two novel subtype families XXf and XXg, with host adaptation at the subtype family level. Notably, C. canis from foxes was genetically distant from those in other hosts. Further subtyping analysis identified three subtypes (IIIeA21G2R1, IIIeA19G2R1 and IIIeA17G2R1) of C. meleagridis and two novel subtype families Xf and Xg of the Cryptosporidium mink genotype. The presence of zoonotic C. canis subtypes in raccoon dogs and C. meleagridis subtypes in foxes suggests that these fur animals might be potential reservoirs for human-pathogenic Cryptosporidium spp.

CRYPTOSPORIDIUM SPP. IN PET DWARF WINTER WHITE RUSSIAN HAMSTERS (PHODOPUS SUNGORIS SUNGORIS) IN CHINA

Cryptosporidium spp. have been identified in a wide range of hosts, such as humans and domestic and wild animals, while less information about the prevalence of Cryptosporidium spp. in pet hamsters is documented. A total of 351 dwarf winter white Russian hamsters' fecal specimens were collected from 6 pet markets from the cities of Luzhou and Ziyang in Sichuan province in the southwestern part of China. The prevalence of Cryptosporidium spp. determined with nested-PCR amplification of the partial small-subunit (SSU) rRNA gene was 39.32% (138/351). The highest prevalence of Cryptosporidium spp. was in pet market 5 (79.49%, 62/78), followed by pet market 6 (38.64%, 17/44). The lowest prevalence of Cryptosporidium spp. was observed in pet market 3 (14.89%, 7/47). Statistically significant differences in the prevalence of Cryptosporidium spp. were observed among different pet markets (χ2 = 76.386, df = 5, P < 0.05), and a further post hoc test revealed that only pet market 5 was significantly different from other pet markets. Molecular analysis showed that 4 different Cryptosporidium species or genotypes were identified: Cryptosporidium parvum (n = 127), Cryptosporidium chipmunk genotype III (n = 6), Cryptosporidium andersoni (n = 4), and Cryptosporidium wrairi (n = 1). The identification of Cryptosporidium spp. was further tested with the 60-kDa glycoprotein (GP60) gene, and the positive rate was 29.7% (41/138). This is the first molecular report on Cryptosporidium spp. infection in dwarf winter white Russian hamsters in China. With C. parvum and C. andersoni being identified in both humans and pet hamsters, these findings suggest that pet hamsters may be potential reservoirs of zoonotic Cryptosporidium species and subtypes.

Intestinal parasites of dogs (Canis lupus familiaris) in Svalbard (Norway): low prevalence and limited transmission with wildlife

Domesticated dogs (Canis lupus familiaris Linnaeus, 1758) are widely kept on all continents and could share parasites with free-living animals. To understand the transmission of intestinal parasites between dogs kept on the four dog stations and wildlife in Svalbard, 170 faecal samples from dogs and 203 faecal samples from wildlife, including Arctic fox (Vulpes lagopus (Linnaeus, 1758); n = 62), Svalbard reindeer (Rangifer tarandus platyrhynchus (Vrolik, 1829); n = 106), sibling vole (Microtus levis Miller, 1908; n = 63), Pink-footed Goose (Anser brachyrhynchus Baillon, 1834; n = 30), Little Auk (Alle alle (Linnaeus, 1758); n = 49), and Black-legged Kittiwake (Rissa tridactyla (Linnaeus, 1758); n = 18), were individually screened for the presence of intestinal parasites using microscopy and PCR and nucleotide sequencing methods. Additionally, the results of the study were compared with previous studies performed in the same area. The roundworm Toxascaris leonina (Linstow, 1902) was found microscopically and by PCR in a dog (n = 1). The specific DNA of three species of parasitic protists was detected in dogs from different yards. Phylogenetic analyses revealed the presence of Cryptosporidium canis Fayer, Trout, Xiao, Morgan, Lal and Dubey, 2001 (n = 1), Encephalitozoon cuniculi Levaditi, Nicolau and Schoen, 1923 genotype II (n = 4), and dog-specific Enterocytozoon bieneusi Desportes, Le Charpentier, Galian, Bernard, Cochand-Priollet, Lavergne, Ravisse and Modigliani, 1985 genotypes (n = 12). This study showed overall a low prevalence of intestinal parasites in dogs in Svalbard and possible but minimal transmission with wildlife.

Zoonotic parasites in farmed exotic animals in China: Implications to public health

Several species of wild mammals are farmed in China as part of the rural development and poverty alleviation, including fur animals, bamboo rats, and macaque monkeys. Concerns have been raised on the potential dispersal of pathogens to humans and other farm animals brought in from native habitats. Numerous studies have been conducted on the genetic identity and public health potential of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in these newly farmed exotic animals. The data generated have shown a high prevalence of the pathogens in farmed wildlife, probably due to the stress from the short captivity and congregation of large numbers of susceptible animals. Host adaptation at species/genotype and subtype levels has reduced the potential for cross-species and zoonotic transmission of pathogens, but the farm environment appears to favor the transmission of some species, genotypes, and subtypes, with reduced pathogen diversity compared with their wild relatives. Most genotypes and subtypes of the pathogens detected appear to be brought in from their native habitats. A few of the subtypes have emerged as human pathogens. One Health measures should be developed to slow the dispersal of indigenous pathogens among farmed exotic animals and prevent their spillover to other farm animals and humans.

Development of a Subtyping Tool for Zoonotic Pathogen Cryptosporidium canis

Cryptosporidium canis is an important cause of cryptosporidiosis in canines and humans. Studies of the transmission characteristics of C. canis are currently hampered by the lack of suitable subtyping tools. In this study, we conducted a genomic survey of the pathogen and developed a subtyping tool targeting the partial 60-kDa glycoprotein gene (gp60). Seventy-six isolates previously identified as C. canis were analyzed using the new subtyping tool. Amplicons of the expected size were obtained from 49 isolates, and phylogenetic analysis identified 10 subtypes clustered into five distinct groups (XXa to XXe). The largest group, XXa, contained 43 isolates from four subtypes that differed slightly from each other at the nucleotide level, while groups XXb to XXe contain one to three isolates each. The similar distributions of subtypes in humans and canines suggest that zoonotic transmission might play an important role in the epidemiology of C. canis In addition, suspected zoonotic transmission of C. canis between dogs and humans in a household was confirmed using the subtyping tool. The subtyping tool and data generated in this study might improve our understanding of the transmission of this zoonotic pathogen.

Molecular characterization of Cryptosporidium spp. in minks (Neovison vison), blue foxes (Vulpes lagopus), and raccoon dogs (Nyctereutes procyonoides) in farms from Xinjiang, Northwest China

The objective of this study was to determine the infection rate and genetic diversity of Cryptosporidium spp. in minks, foxes, and raccoon dogs, farmed in the Xinjiang Uygur Autonomous Region, Northwest China. Fresh fecal specimens were collected from individual cages of farmed minks (n = 214), blue foxes (n = 35), and raccoon dogs (n = 39) and examined using nested PCR based on the Cryptosporidium spp. small subunit rRNA gene. Cryptosporidium spp. was detected in 35 cages (12.2%, 35/288), with a higher infection rate detected in raccoon dogs (20.5%) compared with minks (12.1%) and blue foxes (2.9%). Sequence analysis showed that Cryptosporidium canis was the only species identified in blue foxes and raccoon dogs, while in the 26 Cryptosporidium-positive mink specimens, Cryptosporidium mink genotype (n = 17), C. canis (n = 7), and Cryptosporidium parvum (n = 2) were identified. Further analysis based on the 60-kDa glycoprotein (gp60) gene determined that both C. parvum isolates belonged to the subtype IIdA15G1, while eight of the 17 Cryptosporidium mink genotype isolates were a novel subtype that we have named XeA5G1. To the best of our knowledge, this is the first report of C. parvum subtype IIdA15G1 infection in minks. Since all the Cryptosporidium species/genotypes identified in minks, foxes, and raccoon dogs from Xinjiang have been previously found in humans, our results suggest that these fur animals may play a role in the transmission of zoonotic Cryptosporidium.

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.

The first report of Cryptosporidium spp. in Microtus fuscus (Qinghai vole) and Ochotona curzoniae (wild plateau pika) in the Qinghai-Tibetan Plateau area, China

Cryptosporidium is one of the most important genera of intestinal zoonotic pathogens, which can infect various hosts and cause diarrhoea. There is little available information about the molecular characterisation and epidemiological prevalence of Cryptosporidium spp. in Microtus fuscus (Qinghai vole) and Ochotona curzoniae (wild plateau pika) in the Qinghai-Tibetan Plateau area of Qinghai Province, Northwest China. Therefore, the aim of this study was to determine Cryptosporidium species/genotypes and epidemiological prevalence in these mammals by detecting the SSU rRNA gene by PCR amplification. The Cryptosporidium spp. infection rate was 8.9% (8/90) in Qinghai voles and 6.25% (4/64) in wild plateau pikas. Positive samples were successfully sequenced, and the following Cryptosporidium species were found: C. parvum, C. ubiquitum, C. canis and a novel genotype in Qinghai voles and C. parvum and a novel genotype in wild plateau pikas. This is the first report of Cryptosporidium infections in M. fuscus and wild O. curzoniae in Northwest China. The results suggest the possibility of Cryptosporidium species transmission among these two hosts, the environment, other animals and humans and provide useful molecular epidemiological data for the prevention and control of Cryptosporidium infections in wild animals and the surrounding environments. The results of the present study indicate the existence of Cryptosporidium species infections that have potential public health significance. This is the first report of Cryptosporidium multi-species infections in these animal hosts.

Molecular detection and genetic characterizations of Cryptosporidium spp. in farmed foxes, minks, and raccoon dogs in northeastern China

Cryptosporidium spp. are common intestinal protozoa causing diarrhea in humans and a variety of animal species. With the recent development of fur industry, a large number of fur animals are farmed worldwide, especially in China. The existence of identical Cryptosporidium species/genotypes in humans and fur animals suggests zoonotic potential. In order to assess the presence of zoonotic Cryptosporidium species and/or genotypes in farmed fur animals, 367 fecal specimens were collected from 213 foxes, 114 minks and 40 raccoon dogs farmed in Heilongjiang, Jilin, and Liaoning provinces, northeastern China, during the period from June 2014 to October 2016. By PCR and sequencing of the partial small subunit (SSU) rRNA gene of Cryptosporidium, 20 of 367 (5.4%) animal samples were found to be infected, corresponding to 12 of 213 fox samples (5.6%) and 8 of 114 mink samples (7.0%) screened. Three Cryptosporidium species/genotypes were identified: C. canis (n = 17), C. meleagridis (n = 1) and Cryptosporidium mink genotype (n = 2). Two host-adapted C. canis types (C. canis dog genotype and C. canis fox genotype) were found. By PCR and sequencing of the partial 60 kDa glycoprotein (gp60) encoding gene, one mink genotype isolate was successfully subtyped as XcA5G1R1. The three Cryptosporidium species/genotypes identified in this study have been previously reported in humans suggesting that fur animals infected with Cryptosporidium spp. may pose a risk of zoonotic transmission of cryptosporidiosis, especially for the people working in fur animal farming and processing industry.

Molecular Epidemiology of Cryptosporidiosis in China

Molecular epidemiology of cryptosporidiosis is an active research area in China. The use of genotyping and subtyping tools in prevalence studies has led to the identification of unique characteristics of Cryptosporidium infections in humans and animals. Human cryptosporidiosis in China is exemplified by the high diversity of Cryptosporidium spp. at species and subtype levels, with dominant C. hominis and C. parvum subtypes being rarely detected in other countries. Similarly, preweaned dairy calves, lambs, and goat kids are mostly infected with non-pathogenic Cryptosporidium species (C. bovis in calves and C. xiaoi in lambs and goat kids), with C. parvum starting to appear in dairy calves as a consequence of concentrated animal feeding operations. The latter Cryptosporidium species is dominated by IId subtypes, with IIa subtypes largely absent from the country. Unlike elsewhere, rodents in China appear to be commonly infected with C. parvum IId subtypes, with identical subtypes being found in these animals, calves, other livestock, and humans. In addition to cattle, pigs and chickens appear to be significant contributors to Cryptosporidium contamination in drinking water sources, as reflected by the frequent detection of C. suis, C. baileyi, and C. meleagridis in water samples. Chinese scientists have also made significant contributions to the development of new molecular epidemiological tools for Cryptosporidium spp. and improvements in our understanding of the mechanism involved in the emergence of hyper-transmissible and virulent C. hominis and C. parvum subtypes. Despite this progress, coordinated research efforts should be made to address changes in Cryptosporidium transmission because of rapid economic development in China and to prevent the introduction and spread of virulent and zoonotic Cryptosporidium species and subtypes in farm animals.

Prevalence and Genetic Characterization of Cryptosporidium Infection in Java Sparrows (Lonchura oryzivora) in Northern China

Cryptosporidiosis is a cosmopolitan parasitosis that affects a wide range of hosts including birds. As information concerning Cryptosporidium in birds is limited, the present study examined the prevalence and genotypes of Cryptosporidium in Java sparrows in Beijing and Shangqiu, northern China. Three hundred and fifty fecal samples were collected from Java sparrows (Lonchura oryzivora, 225 white Java sparrows and 125 gray Java sparrows) in Beijing and Shangqiu in October 2015, and the samples were examined by PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene. The overall Cryptosporidium prevalence is 13.42% (47/350), with 16.44% (37/225) in white Java sparrows and 8.00% (10/125) in gray Java sparrows. Cryptosporidium prevalence was 9.82% (16/163) in Java sparrows from Beijing and 16.58% (31/187) in Java sparrows from Shangqiu. The prevalence of Cryptosporidium in females and males was 40.63% (26/64) and 7.34% (21/286), respectively. The Cryptosporidium prevalence in Java sparrows of different ages varied from 10.47% to 16.33%. Sequence analysis of the SSU rRNA gene revealed that all the samples represented C. baileyi. This is the first report of Cryptosporidium in gray Java sparrows in China, which extend the host range for C. baileyi. These results provide baseline information for further studies of molecular epidemiology and control of Cryptosporidium infection in poultry in China.

First description of Cryptosporidium ubiquitum XIIa subtype family in farmed fur animals

This study investigated the prevalence of Cryptosporidium in farmed fur animals in the Czech Republic and Poland. A total of 480 faecal samples were collected from fur animals, including 300 American mink (Mustela vison), 60 silver foxes (Vulpes vulpes), 50 long-tailed chinchillas (Chinchilla lanigera), and 70 nutrias (Myocastor coypus), at 14 farms. Samples were examined for the presence of Cryptosporidium using microscopy (following aniline-carbol-methyl violet staining) and sequence analysis of PCR amplified products. Three mink and two chinchillas from two different farms tested positive for Cryptosporidium ubiquitum DNA. The presence of C. ubiquitum DNA was not associated with diarrhoea. Subtyping of C. ubiquitum isolates by sequence analysis of the 60-kDa glycoprotein gene showed that isolates belonged to the XIIa subtype family, which was previously restricted to humans and ruminants. This suggests that C. ubiquitum subtype XIIa has a broader host range than previously reported.

Occurrence and molecular genotyping of Giardia duodenalis and Cryptosporidium spp. in wild mesocarnivores in Spain

There is a surprisingly scarce amount of epidemiological and molecular data on the prevalence, frequency, and diversity of the intestinal protozoan parasites Giardia duodenalis and Cryptosporidium spp. in wildlife in general and mesocarnivore species in particular. Consequently, the extent of the cyst/oocyst environmental contamination attributable to these wild host species and their potential implications for public veterinary health remain largely unknown. In this molecular epidemiological survey a total of 193 individual faecal samples from badgers (Meles meles, n=70), ferrets (Mustela putorius furo, n=2), genets (Genetta genetta, n=6), Iberian lynxes (Lynx pardinus, n=6), beech martens (Martes foina, n=8), mongooses (Herpestes ichneumon, n=2), otters (Lutra lutra, n=2), polecats (Mustela putorius, n=2), red foxes (Vulpes vulpes, n=87), wildcats (Felis silvestris, n=2), and wolves (Canis lupus, n=6) were obtained from road-killed, hunted, and accidentally found carcasses, and from camera-trap surveys or animals entering rescue shelters, during the period December 2003-April 2016. Investigated specimens were collected in five Spanish autonomous regions including Andalusia (n=1), Asturias (n=69), Basque Country (n=49), Castile-La Mancha (n=38), and Extremadura (n=36). The presence of cysts/oocysts was confirmed by PCR-based methods targeting the small subunit (ssu) ribosomal RNA gene of these parasite species. Genotyping of the obtained isolates were attempted at appropriate markers including the glutamate dehydrogenase (G. duodenalis) and the 60-kDa glycoprotein (C. parvum and C. ubiquitum) loci. Overall, G. duodenalis was detected in 8% (7/87) of red foxes, a single beech marten, and a single wolf, respectively. Cryptosporidium was identified in 3% (2/70) of badgers, 8% (7/87) of red foxes, a single genet, and a single mongoose, respectively. None of the nine G. duodenalis isolates generated could be genotyped at the assemblage/sub-assemblage level. Out of the nine Cryptosporidium isolates successfully characterized, three were identified as C. canis (one in a mongoose and two in red foxes), and three as C. parvum (one in a badger and three in red foxes). The remaining three isolates were assigned to C. felis (in a red fox), C. hominis (in a badger), and C. ubiquitum (in a red fox), respectively. Two additional Cryptosporidium isolates infecting a badger and a genet, respectively, were untypable. The red fox was confirmed as a suitable host of potentially zoonotic Cryptosporidium species, mainly C. parvum and C. ubiquitum. The high mobility and wide home range of red foxes, together with their increasing presence in urban and peri-urban settings, may led to the overlapping of sylvatic and domestic cycles of the parasite, and consequently, to an increased risk of cryptosporidiosis in production animals and humans. The detection of C. hominis oocysts in a badger raises the question of whether this finding represents a true infection or a sporadic event of mechanical passage of C. hominis oocyst of anthroponotic origin.