Wildlife-associated Cryptosporidium are an emerging cause of cryptosporidiosis in humans. The present study was undertaken to determine the extent to which North American tree squirrels and ground squirrels host zoonotic Cryptosporidium species and genotypes. Fragments of the Cryptosporidium 18S rRNA and actin genes were amplified and sequenced from fecal samples obtained from three tree squirrel and three ground squirrel species. In tree squirrels, Cryptosporidium was identified in 40.5% (17/42) of American red squirrels (Tamiasciurus hudsonicus), 40.4% (55/136) of eastern gray squirrels (Sciurus carolinensis), and 28.6% (2/7) of fox squirrels (Sciurus niger). Human-pathogenic Cryptosporidium ubiquitum and Cryptosporidium skunk genotype were the most prevalent species/genotypes in tree squirrels. Because tree squirrels live in close proximity to humans and are frequently infected with potentially zoonotic Cryptosporidium species/genotypes, they may be a significant reservoir of infection in humans. In ground squirrels, Cryptosporidium was detected in 70.2% (33/47) of 13-lined ground squirrels (Ictidomys tridecemlineatus), 35.1% (27/77) of black-tailed prairie dogs (Cynomys ludovicianus), and the only golden-mantled ground squirrel (Callospermophilus lateralis) that was sampled. Cryptosporidium rubeyi and ground squirrel genotypes I, II, and III were identified in isolates from these ground squirrel species. In contrast to the Cryptosporidium infecting tree squirrels, these species/genotypes appear to be specific for ground squirrels and are not associated with human disease.
- MeSH
- Cryptosporidium * classification genetics pathogenicity MeSH
- Feces parasitology MeSH
- Phylogeny MeSH
- Host Specificity MeSH
- Cryptosporidiosis parasitology MeSH
- Sciuridae parasitology physiology MeSH
- Homing Behavior MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- North America MeSH
Cryptosporidium Tyzzer, 1910 is one of the most common protistan parasites of vertebrates. The results of this study provide the first data on Cryptosporidium diversity in the European ground squirrel Spermophilus citellus (Linnaeus). A total of 128 faecal samples of European ground squirrels from 39 localities in the Czech Republic were analysed for the presence of Cryptosporidium spp. by microscopy and PCR/sequence analysis of small subunit ribosomal RNA (SSU) and the actin gene. While the microscopical examination did not reveal the presence of any Cryptosporidium oocysts, eight samples from six localities were PCR-positive. Phylogenetic analyses revealed the presence of five different Cryptosporidium spp. isolates. Four isolates, designated as Cryptosporidium sp. isolate Sc01-04, detected in wild populations and never recorded before, clustered closely to Cryptosporidium genotypes that have previously been found in North American ground squirrels' species. Cryptosporidium sciurinum Prediger, Ježková, Holubová, Sak, Konečný, Rost, McEvoy, Rajský et Kváč, 2021 was found in an animal sanctuary. Because C. sciurinum had previously been detected in Eurasian red squirrels Sciurus vulgaris Linnaeus at the same facility, it can be concluded that this Cryptosporidium was transmitted from tree squirrels to ground squirrels within the animal sanctuary. The results indicate that populations of European and North American ground squirrels are parasitised by different Cryptosporidium spp. At the same time, this is the first description of the occurrence of C. sciurinum in ground squirrels.
- MeSH
- Cryptosporidium * MeSH
- Feces parasitology MeSH
- Phylogeny MeSH
- Cryptosporidiosis * epidemiology parasitology MeSH
- Sciuridae parasitology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- North America MeSH
The present study was undertaken to describe Cryptosporidium spp. infection in tree squirrels from 17 locations in Northern Italy. A total of 357 squirrels were examined, including species native to Europe (Sciurus vulgaris; n=123), and species introduced from North America (Sciurus carolinensis; n=162) and Southeast Asia (Callosciurus erythraeus; n=72). Faecal samples of all squirrels were examined for the presence of Cryptosporidium infection by microscopy (flotation method) and PCR/sequence analysis of the Cryptosporidium 18S rRNA, actin, and gp60 genes. Despite the overlapping ranges of native and introduced tree squirrel species in the study area, they host different Cryptosporidium spp. Sciurus vulgaris were exclusively infected with Cryptosporidium ferret genotype (n=13) belonging to three novel gp60 subtypes, VIIIb-VIIId. Sciurus carolinensis hosted C. ubiquitum subtype XIIb (n=2), Cryptosporidium skunk genotype subtype XVIa (n=3), and chipmunk genotype I subtype XIVa (n=1). Cryptosporidium chipmunk genotype I subtype XIVa was also found in two C. erythraeus. Comparing data from this and previous studies, we propose that Cryptosporidium skunk genotype and possibly C. ubiquitum subtype XIIb were introduced to Europe with eastern grey squirrels. Cryptosporidium chipmunk genotype I and ferret genotype were associated with high intensity infections, but there was no association with diarrhoea.
- MeSH
- Cryptosporidium classification genetics physiology MeSH
- Feces parasitology MeSH
- Host Specificity MeSH
- Host-Parasite Interactions MeSH
- Cryptosporidiosis parasitology MeSH
- Genes, Protozoan genetics MeSH
- Animal Distribution MeSH
- Sciuridae parasitology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Italy MeSH
The social brain hypothesis (SBH) contends that cognitive demands associated with living in cohesive social groups favour the evolution of large brains. Although the correlation between relative brain size and sociality reported in various groups of birds and mammals provides broad empirical support for this hypothesis, it has never been tested in rodents, the largest mammalian order. Here, we test the predictions of the SBH in the ground squirrels from the tribe Marmotini. These rodents exhibit levels of sociality ranging from solitary and single-family female kin groups to egalitarian polygynous harems but feature similar ecologies and life-history traits. We found little support for the association between increase in sociality and increase in relative brain size. Thus, sociality does not drive the evolution of encephalization in this group of rodents, a finding inconsistent with the SBH. However, body mass and absolute brain size increase with sociality. These findings suggest that increased social complexity in the ground squirrels goes hand in hand with larger body mass and brain size, which are tightly coupled to each other.
- MeSH
- Biological Evolution MeSH
- Brain anatomy & histology MeSH
- Sex Characteristics MeSH
- Sciuridae anatomy & histology physiology MeSH
- Social Behavior * MeSH
- Organ Size MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
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.
- MeSH
- Cryptosporidium * isolation & purification genetics classification MeSH
- Adult MeSH
- Feces * parasitology MeSH
- Phylogeny MeSH
- Gastroenteritis parasitology veterinary MeSH
- Cryptosporidiosis * parasitology epidemiology MeSH
- Humans MeSH
- Sciuridae * parasitology MeSH
- Disease Reservoirs parasitology MeSH
- Zoonoses * parasitology 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
We investigated the genotypes of Cryptosporidium infecting red squirrels (Sciurus vulgaris L.) in two areas of the Western Alps in Italy. Examination of 141 faecal samples from 70 red squirrels revealed oocysts of Cryptosporidium in 17 animals (24.3%). Based on 18S rRNA gene sequencing, two genotypes of Cryptosporidium species were found: 15 squirrels were positive for the Cryptosporidium ferret genotype and 2 for the Cryptosporidium chipmunk genotype I. The occurrence and intensity of Cryptosporidium infection did not differ between the study areas or sex. More than 85% of the positive animals were adults; however no difference was found between Cryptosporidium infection in the juvenile and adult age groups. Oocysts of the Cryptosporidium ferret genotype measured 5.5 ± 0.3 × 5.2 ± 0.2 µm (shape index 1.06) and the Cryptosporidium chipmunk genotype I 5.8 ± 0.3 × 5.4 ± 0.3 µm (shape index 1.07). Neonatal and adult CD1 and BABL/c mice inoculated with 1 × 103 fresh oocysts of both genotypes did not produce detectable infection.
- MeSH
- Cryptosporidium cytology genetics isolation & purification classification MeSH
- Feces parasitology MeSH
- Genotype MeSH
- Cryptosporidiosis epidemiology parasitology veterinary MeSH
- Molecular Sequence Data MeSH
- Mice, Inbred BALB C MeSH
- Mice MeSH
- Rodent Diseases epidemiology parasitology MeSH
- DNA, Protozoan genetics chemistry MeSH
- DNA, Ribosomal genetics chemistry MeSH
- RNA, Ribosomal, 18S genetics MeSH
- Sciuridae parasitology MeSH
- Sequence Analysis, DNA MeSH
- Sex Factors MeSH
- Age Factors MeSH
- Geography MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Geographicals
- Italy MeSH
The European ground squirrel (Spermophilus citellus) emits alarm calls that warn conspecifics of potential danger. Although it has been observed that inexperienced juveniles of this species emit alarm calls that sound similar to those of adults, studies focusing on juvenile alarm calls are lacking. We analyzed the acoustic structure of alarm calls emitted by six permanently marked European ground squirrels living in a semi-natural enclosure when they were juveniles and after 1 year as adults. We found that the acoustic structure of the juvenile alarm calls was significantly different from those of adults and that the alarm calls underwent nearly the same changes in all studied individuals. All juveniles emitted alarm calls consisting of one element with almost constant frequency, but their alarm calls included a second frequency-modulated element after their first hibernation as adults. Our data show that the duration of the first element is significantly shorter in adults than in juveniles. Additionally, the frequency of the first element is significantly higher in adults than in juveniles. Similar to previous findings in other Palearctic ground squirrel species, our data are inconsistent with the assumption that juvenile mammals emit vocalizations with higher fundamental frequencies than adults. However, our results do not support the previously suggested hypothesis that juvenile ground squirrels conceal information regarding their age in their alarm calls because we found significant differences in alarm calls of juveniles and adults.
The Anatolian ground squirrel Spermophilus xanthoprymnus like other ground-dwelling sciurids, emits alarm calls in the presence of predators. In this study, we provide a description of the acoustic structure of alarm call of this species and compare it to those of two closely related species, the Taurus ground squirrel Spermophilus taurensis and the European ground squirrel Spermophilus citellus. The alarm call of S. xanthoprymnus is a tonal sound mostly consisting of two different elements-the first element has low frequency modulation while the second element is highly frequency modulated. A similar basic structure can be found in the alarm calls of some other old world ground squirrel species of the genus Spermophilus, including S. taurensis and S. citellus. Despite this similarity, we found that these three species can be clearly distinguished on the basis of their alarm calls. Differences in the acoustic structure of S. xanthoprymnus and S. taurensis calls are especially remarkable, as these two species were considered to be conspecific until 2007. S. xanthoprymnus and S. taurensis were also demonstrated to have closer acoustic similarity, which is in contrast to results based on molecular data indicating that S. taurensis is most closely related to S. citellus.
- MeSH
- Acoustics MeSH
- Species Specificity MeSH
- Sciuridae classification physiology MeSH
- Cluster Analysis MeSH
- Vocalization, Animal physiology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
