Cryptosporidium mortiferum, a parasite transmitted by squirrels, is beginning to spread in Europe. C. mortiferum was detected in a symptomatic human. A 44-year-old man from the Czech Republic suffered from gastroenteritis characterized by abdominal pain, nausea, and loose stools. Molecular analyses confirmed the XIVaA20G2T1 subtype in the patient's stool. At the same time, the same subtype of C. mortiferum was detected in three red squirrels and two ground squirrels in the area where the patient lived. The intensity of the infection was significantly higher in the red squirrels that died, while the ground squirrels showed no symptoms. The results of the study indicate that red squirrels and ground squirrels are the reservoirs for the infection.

• Keywords
• Cryptosporidium mortiferum, human, infection, squirrels,
• MeSH
• Cryptosporidium * genetics   isolation & purification   classification   MeSH
• Adult MeSH
• Feces parasitology   MeSH
• Phylogeny MeSH
• Gastroenteritis parasitology   MeSH
• Cryptosporidiosis * parasitology   transmission   epidemiology   diagnosis   MeSH
• Humans MeSH
• Sciuridae * parasitology   MeSH
• Disease Reservoirs parasitology   MeSH
• Zoonoses * parasitology   transmission   MeSH
• Animals MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Case Reports MeSH
• Geographicals
• Czech Republic MeSH
• Europe MeSH

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. 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

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