Most cited article - PubMed ID 25772204
Highly divergent 18S rRNA gene paralogs in a Cryptosporidium genotype from eastern chipmunks (Tamias striatus)
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
Cryptosporidium spp., common parasites of vertebrates, remain poorly studied in wildlife. This study describes the novel Cryptosporidium species adapted to nutrias (Myocastor coypus). A total of 150 faecal samples of feral nutria were collected from locations in the Czech Republic and Slovakia and examined for Cryptosporidium spp. oocysts and specific DNA at the SSU, actin, HSP70, and gp60 loci. Molecular analyses revealed the presence of C. parvum (n = 1), C. ubiquitum subtype family XIId (n = 5) and Cryptosporidium myocastoris n. sp. XXIIa (n = 2), and XXIIb (n = 3). Only nutrias positive for C. myocastoris shed microscopically detectable oocysts, which measured 4.8-5.2 × 4.7-5.0 µm, and oocysts were infectious for experimentally infected nutrias with a prepatent period of 5-6 days, although not for mice, gerbils, or chickens. The infection was localised in jejunum and ileum without observable macroscopic changes. The microvilli adjacent to attached stages responded by elongating. Clinical signs were not observed in naturally or experimentally infected nutrias. Phylogenetic analyses at SSU, actin, and HSP70 loci demonstrated that C. myocastoris n. sp. is distinct from other valid Cryptosporidium species.
- Keywords
- adaptation, biology, course of infection, infectivity, oocyst size, parasite, phylogeny, prevalence,
- Publication type
- Journal Article MeSH
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
Proventriculus and intestinal samples from 70 North American red-winged blackbirds (Agelaius phoeniceus; order Passeriformes) were examined for the presence of Cryptosporidium by PCR amplification and sequence analysis of the 18S ribosomal RNA (18S rRNA), actin, and 70-kDa heat shock protein (HSP70) genes. Twelve birds (17.1 %) were positive for the Cryptosporidium 18S rRNA gene: six birds were positive at the proventriculus site only and six birds were positive at the proventriculus and intestinal sites. Sequence analysis of the 18S rRNA, actin and HSP70 genes showed the presence of the gastric species Cryptosporidium galli in a single proventriculus sample and a closely related genotype, which we have named Cryptosporidium avian genotype VI, in all other positive samples. These findings contribute to our understanding of Cryptosporidium diversification in passerines, the largest avian order.
- Keywords
- Avian genotype VI, Cryptosporidium, Cryptosporidium galli, Intestine, Passerines, Proventriculus, Red-winged blackbird,
- MeSH
- Cryptosporidium classification MeSH
- Genotype MeSH
- Cryptosporidiosis epidemiology parasitology MeSH
- Bird Diseases epidemiology parasitology MeSH
- Passeriformes * MeSH
- Polymerase Chain Reaction MeSH
- HSP70 Heat-Shock Proteins genetics metabolism MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- United States epidemiology MeSH
- Names of Substances
- HSP70 Heat-Shock Proteins MeSH
- RNA, Ribosomal, 18S MeSH