Most cited article - PubMed ID 23791796
Coevolution of Cryptosporidium tyzzeri and the house mouse (Mus musculus)
BACKGROUND: Cryptosporidium spp. are globally distributed parasites that infect epithelial cells in the microvillus border of the gastrointestinal tract of all classes of vertebrates. Cryptosporidium chipmunk genotype I is a common parasite in North American tree squirrels. It was introduced into Europe with eastern gray squirrels and poses an infection risk to native European squirrel species, for which infection is fatal. In this study, the biology and genetic variability of different isolates of chipmunk genotype I were investigated. METHODS: The genetic diversity of Cryptosporidium chipmunk genotype I was analyzed by PCR/sequencing of the SSU rRNA, actin, HSP70, COWP, TRAP-C1 and gp60 genes. The biology of chipmunk genotype I, including oocyst size, localization of the life cycle stages and pathology, was examined by light and electron microscopy and histology. Infectivity to Eurasian red squirrels and eastern gray squirrels was verified experimentally. RESULTS: Phylogenic analyses at studied genes revealed that chipmunk genotype I is genetically distinct from other Cryptosporidium spp. No detectable infection occurred in chickens and guinea pigs experimentally inoculated with chipmunk genotype I, while in laboratory mice, ferrets, gerbils, Eurasian red squirrels and eastern gray squirrels, oocyst shedding began between 4 and 11 days post infection. While infection in mice, gerbils, ferrets and eastern gray squirrels was asymptomatic or had mild clinical signs, Eurasian red squirrels developed severe cryptosporidiosis that resulted in host death. The rapid onset of clinical signs characterized by severe diarrhea, apathy, loss of appetite and subsequent death of the individual may explain the sporadic occurrence of this Cryptosporidium in field studies and its concurrent spread in the population of native European squirrels. Oocysts obtained from a naturally infected human, the original inoculum, were 5.64 × 5.37 μm and did not differ in size from oocysts obtained from experimentally infected hosts. Cryptosporidium chipmunk genotype I infection was localized exclusively in the cecum and anterior part of the colon. CONCLUSIONS: Based on these differences in genetics, host specificity and pathogenicity, we propose the name Cryptosporidium mortiferum n. sp. for this parasite previously known as Cryptosporidium chipmunk genotype I.
- Keywords
- Biology, Course of infection, Cryptosporidiosis, Genetic diversity, Mortality, Oocyst size, Phylogeny,
- MeSH
- Cryptosporidiidae * MeSH
- Cryptosporidium * MeSH
- Feces parasitology MeSH
- Ferrets MeSH
- Phylogeny MeSH
- Genotype MeSH
- Gerbillinae MeSH
- Cryptosporidiosis * parasitology MeSH
- Chickens MeSH
- Humans MeSH
- Guinea Pigs MeSH
- Mice MeSH
- Oocysts MeSH
- Sciuridae parasitology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Guinea Pigs MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Cryptosporidium spp. are common protozoan pathogens in mammals. With pet rodents being integrated into modern life, the potential roles of them in transmitting parasites to humans need assessments. In the present study, we examined the occurrence of Cryptosporidium spp. in pet rodents in Guangdong, south China. A total of 697 fecal samples were collected from 11 species of rodents in seven pet shops, one pet market and one farm. Cryptosporidium spp. were identified by PCR analysis of the small subunit rRNA gene. An overall infection rate of 36.9% (257/697) was obtained, with infection rates varying from 9.3% in chinchillas, 52.3% in guinea pigs, 57.1% in squirrels, to 68.4% in cricetid animals. Nine Cryptosporidium species and genotypes were identified, including C. wrairi (in 129 guinea pigs), C. andersoni (in 34 hamsters), C. homai (in 32 guinea pigs), Cryptosporidium hamster genotype (in 30 hamsters), C. ubiquitum (in 24 chinchillas and squirrels), C. parvum (in 2 chinchillas), Cryptosporidium ferret genotype (in 2 chipmunks), C. muris (in 1 hamster and 1 guinea pig), and Cryptosporidium chipmunk genotype V (in 1 chinchilla and 1 chipmunk). Sequence analysis of the 60 kDa glycoprotein gene identified three subtype families of C. ubiquitum, including family XIId in 15 chinchillas, XIIa in 5 chinchillas, and a new subtype family (XIIi) in 1 squirrel. The identification of C. parvum and C. ubiquitum in pet rodents suggests that these animals, especially chinchillas, could serve as reservoirs of human-pathogenic Cryptosporidium spp. Hygiene should be practiced in the rear and care of these animals, and One Health measures should be developed to reduce the occurrence of zoonotic Cryptosporidium infections due to contact with pet rodents.
- Keywords
- Cryptosporidium, Molecular epidemiology, One health, Pet rodents, Zoonosis,
- Publication type
- Journal Article MeSH
Cryptosporidium spp. are common protozoan pathogens in mammals. The diversity and biology of Cryptosporidium in tree squirrels are not well studied. A total of 258 Eurasian red squirrels (Sciurus vulgaris) from 25 and 15 locations in the Czech Republic and Slovakia, respectively, were examined for Cryptosporidium spp. oocysts and specific DNA at the SSU, actin, HSP70, TRAP-C1, COWP, and gp60 loci. Out of 26 positive animals, only juveniles (9/12) were microscopically positive (18,000 to 72,000 OPG), and molecular analyses revealed the presence of Cryptosporidium sp. ferret genotype in all specimens. Oocysts obtained from naturally-infected squirrels measured 5.54-5.22 μm and were not infectious for laboratory mice (BALB/c and SCID), Mongolian gerbils, Guinea pigs, Southern multimammate mice, chickens, or budgerigars. None of naturally infected squirrels showed clinical signs of disease. The frequency of occurrence of the ferret genotype in squirrels did not vary statistically based on host age, gender or country of capture. Phylogenetic analysis of sequences from six loci revealed that Cryptosporidium sp. ferret genotype is genetically distinct from the currently accepted Cryptosporidium species. Morphological and biological data from this and previous studies support the establishment of Cryptosporidium sp. ferret genotype as a new species, Cryptosporidium sciurinum n. sp.
- Keywords
- Cryptosporidium sp. ferret genotype, biology, course of infection, infectivity, occurrence, oocyst size, phylogeny,
- Publication type
- Journal Article MeSH
Detection and quantification of coccidia in studies of wildlife can be challenging. Therefore, prevalence of coccidia is often not assessed at the parasite species level in non-livestock animals. Parasite species - specific prevalences are especially important when studying evolutionary questions in wild populations. We tested whether increased host population density increases prevalence of individual Eimeria species at the farm level, as predicted by epidemiological theory. We studied free-living commensal populations of the house mouse (Mus musculus) in Germany, and established a strategy to detect and quantify Eimeria infections. We show that a novel diagnostic primer targeting the apicoplast genome (Ap5) and coprological assessment after flotation provide complementary detection results increasing sensitivity. Genotyping PCRs confirm detection in a subset of samples and cross-validation of different PCR markers does not indicate bias towards a particular parasite species in genotyping. We were able to detect double infections and to determine the preferred niche of each parasite species along the distal-proximal axis of the intestine. Parasite genotyping from tissue samples provides additional indication for the absence of species bias in genotyping amplifications. Three Eimeria species were found infecting house mice at different prevalences: Eimeria ferrisi (16.7%; 95% CI 13.2-20.7), E. falciformis (4.2%; 95% CI 2.6-6.8) and E. vermiformis (1.9%; 95% CI 0.9-3.8). We also find that mice in dense populations are more likely to be infected with E. falciformis and E. ferrisi. We provide methods for the assessment of prevalences of coccidia at the species level in rodent systems. We show and discuss how such data can help to test hypotheses in ecology, evolution and epidemiology on a species level.
- Keywords
- Coccidia, Diagnostic PCR, Eimeria, House mice, Species-specific prevalence, qPCR,
- Publication type
- Journal Article MeSH
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.
- Keywords
- Epidemiology, Molecular analyses, Phylogeny, Rodentia,
- MeSH
- Cryptosporidium genetics MeSH
- Genetic Variation * MeSH
- Genotype MeSH
- Cryptosporidiosis parasitology MeSH
- Murinae microbiology MeSH
- Mice MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
- Names of Substances
- RNA, Ribosomal, 18S MeSH
The CD94 receptor, expressed on natural killer (NK) and CD8+ T cells, is known as a relatively non-polymorphic receptor with orthologues in humans, other primates, cattle, and rodents. In the house mouse (Mus musculus), a single allele is highly conserved among laboratory strains, and reports of allelic variation in lab- or wild-living mice are lacking, except for deficiency in one lab strain (DBA/2J). The non-classical MHC-I molecule Qa-1b is the ligand for mouse CD94/NKG2A, presenting alternative non-americ fragment of leader peptides (Qa-1 determinant modifier (Qdm)) from classical MHC-I molecules. Here, we report a novel allele identified in free-living house mice captured in Norway, living among individuals carrying the canonical Cd94 allele. The novel Cd94LocA allele encodes 12 amino acid substitutions in the extracellular lectin-like domain. Flow cytometric analysis of primary NK cells and transfected cells indicates that the substitutions prevent binding of CD94 mAb and Qa-1b/Qdm tetramers. Our data further indicate correlation of Cd94 polymorphism with the two major subspecies of house mice in Europe. Together, these findings suggest that the Cd94LocA/NKG2A heterodimeric receptor is widely expressed among M. musculus subspecies musculus, with ligand-binding properties different from mice of subspecies domesticus, such as the C57BL/6 strain.
- Keywords
- Comparative immunology/evolution, Genomics, Inhibitory/activating receptors, MHC, NK cell,
- MeSH
- Alleles MeSH
- Killer Cells, Natural metabolism MeSH
- CD8-Positive T-Lymphocytes metabolism MeSH
- CHO Cells MeSH
- Cricetulus MeSH
- Species Specificity MeSH
- HEK293 Cells MeSH
- Cricetinae MeSH
- NK Cell Lectin-Like Receptor Subfamily C chemistry genetics metabolism MeSH
- NK Cell Lectin-Like Receptor Subfamily D chemistry genetics metabolism MeSH
- Humans MeSH
- Histocompatibility Antigens Class I chemistry genetics metabolism MeSH
- Protein Multimerization MeSH
- Mice, Inbred C57BL MeSH
- Mice, Inbred DBA MeSH
- Peptides chemistry genetics metabolism MeSH
- Polymorphism, Genetic * MeSH
- Amino Acid Sequence MeSH
- Sequence Homology, Amino Acid MeSH
- Protein Binding MeSH
- Animals MeSH
- Check Tag
- Cricetinae MeSH
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Norway MeSH
- Names of Substances
- NK Cell Lectin-Like Receptor Subfamily C MeSH
- NK Cell Lectin-Like Receptor Subfamily D MeSH
- Histocompatibility Antigens Class I MeSH
- Peptides MeSH
- Q surface antigens MeSH Browser
- Qdm protein, mouse MeSH Browser
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.
- Keywords
- Experimental infection, Rodentia, molecular analyses, oocyst size, phylogeny, voles,
- MeSH
- Arvicolinae parasitology MeSH
- Cryptosporidium classification genetics ultrastructure MeSH
- Feces parasitology MeSH
- Microscopy, Fluorescence MeSH
- Phylogeny MeSH
- Gastrointestinal Tract parasitology pathology ultrastructure MeSH
- Genetic Variation MeSH
- Microscopy, Interference MeSH
- Cryptosporidiosis epidemiology parasitology transmission MeSH
- Rats MeSH
- Chickens MeSH
- Microscopy, Electron, Scanning MeSH
- Murinae MeSH
- Mice, Inbred BALB C MeSH
- Mice, Inbred C57BL MeSH
- Mice MeSH
- Rodent Diseases epidemiology parasitology transmission MeSH
- Polymerase Chain Reaction MeSH
- Prevalence MeSH
- DNA, Protozoan chemistry genetics isolation & purification MeSH
- RNA, Ribosomal genetics MeSH
- Base Sequence MeSH
- Sequence Alignment veterinary MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Geographicals
- Czech Republic MeSH
- Names of Substances
- DNA, Protozoan MeSH
- RNA, Ribosomal MeSH
We undertook a study on Cryptosporidium spp. in wild cricetid rodents. Fecal samples were collected from meadow voles (Microtus pennsylvanicus), southern red-backed voles (Myodes gapperi), woodland voles (Microtus pinetorum), muskrats (Ondatra zibethicus) and Peromyscus spp. mice in North America, and from bank voles (Myodes glareolus) and common voles (Microtus arvalis) in Europe. Isolates were characterized by sequence and phylogenetic analyses of the small subunit ribosomal RNA (SSU) and actin genes. Overall, 33·2% (362/1089) of cricetids tested positive for Cryptosporidium, with a greater prevalence in cricetids from North America (50·7%; 302/596) than Europe (12·1%; 60/493). Principal Coordinate analysis separated SSU sequences into three major groups (G1-G3), each represented by sequences from North American and European cricetids. A maximum likelihood tree of SSU sequences had low bootstrap support and showed G1 to be more heterogeneous than G2 or G3. Actin and concatenated actin-SSU trees, which were better resolved and had higher bootstrap support than the SSU phylogeny, showed that closely related cricetid hosts in Europe and North America are infected with closely related Cryptosporidium genotypes. Cricetids were not major reservoirs of human pathogenic Cryptosporidium spp.
- Keywords
- Cryptosporidium, Cricetidae, biogeography, phylogenetics,
- MeSH
- Arvicolinae parasitology MeSH
- Cryptosporidium classification isolation & purification pathogenicity physiology MeSH
- Animals, Wild parasitology MeSH
- Feces parasitology MeSH
- Phylogeny MeSH
- Phylogeography MeSH
- Genotype MeSH
- Rodentia parasitology MeSH
- Cryptosporidiosis epidemiology parasitology MeSH
- Mice parasitology MeSH
- RNA, Ribosomal genetics MeSH
- Sequence Analysis, DNA MeSH
- Disease Reservoirs parasitology MeSH
- Animals MeSH
- Check Tag
- Mice parasitology MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Europe epidemiology MeSH
- North America epidemiology MeSH
- Names of Substances
- RNA, Ribosomal MeSH
IntroductionThis paper reviews the current knowledge and understanding of Cryptosporidium spp. and Giardia spp. in humans, animals and the environment in 10 countries in the eastern part of Europe: Bosnia and Herzegovina, Croatia, Czech Republic, Estonia, Hungary, Latvia, Poland, Romania, Serbia and Slovenia. Methods: Published scientific papers and conference proceedings from the international and local literature, official national health service reports, national databases and doctoral theses in local languages were reviewed to provide an extensive overview on the epidemiology, diagnostics and research on these pathogens, as well as analyse knowledge gaps and areas for further research. Results:Cryptosporidium spp. and Giardia spp. were found to be common in eastern Europe, but the results from different countries are difficult to compare because of variations in reporting practices and detection methodologies used. Conclusion: Upgrading and making the diagnosis/detection procedures more uniform is recommended throughout the region. Public health authorities should actively work towards increasing reporting and standardising reporting practices as these prerequisites for the reported data to be valid and therefore necessary for appropriate control plans.
- Keywords
- One Health, cryptosporidiosis, giardiasis, zoonosis,
- MeSH
- Cryptosporidium genetics isolation & purification MeSH
- Feces parasitology MeSH
- Giardia genetics isolation & purification MeSH
- Giardiasis epidemiology parasitology MeSH
- Cryptosporidiosis epidemiology parasitology MeSH
- Real-Time Polymerase Chain Reaction MeSH
- Humans MeSH
- Foodborne Diseases epidemiology parasitology MeSH
- Prevalence MeSH
- Public Health * MeSH
- Environment MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
- Geographicals
- Europe, Eastern epidemiology MeSH
Many emerging infections are RNA virus spillovers from animal reservoirs. Reservoir identification is necessary for predicting the geographic extent of infection risk, but rarely are taxonomic levels below the animal species considered as reservoir, and only key circumstances in nature and methodology allow intrinsic virus-host associations to be distinguished from simple geographic (co-)isolation. We sampled and genetically characterized in detail a contact zone of two subtaxa of the rodent Mastomys natalensis in Tanzania. We find two distinct arenaviruses, Gairo and Morogoro virus, each spatially confined to a single M. natalensis subtaxon, only co-occurring at the contact zone's centre. Inter-subtaxon hybridization at this centre and a continuum of quality habitat for M. natalensis show that both viruses have the ecological opportunity to spread into the other substaxon's range, but do not, strongly suggesting host-intrinsic barriers. Such barriers could explain why human cases of another M. natalensis-borne arenavirus, Lassa virus, are limited to West Africa.
- MeSH
- Arenavirus classification metabolism physiology MeSH
- Species Specificity MeSH
- Phylogeography MeSH
- Lassa Fever virology MeSH
- Humans MeSH
- Murinae virology MeSH
- Rodent Diseases virology MeSH
- Lassa virus physiology MeSH
- Disease Reservoirs virology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Tanzania MeSH