Public health and ecological significance of rodents in Cryptosporidium infections

Zoonotic Ectoparasites Infesting Commensal Invasive Murid Rodents

Rodents are associated with the spread of deadly zoonotic and emerging infectious diseases. Their widespread distribution is strongly linked to their ability to thrive in human-altered environments with access to food and shelter. Thus, humans are exposed to zoonotic agents that can spread and infect them directly and indirectly. We sourced published literature on ectoparasites associated with Rattus rattus, R. norvegicus, and Mus musculus from various academic databases such as Google Scholar, PubMed, Web of Science, and Scopus. The relevant literature was screened and selected in R statistical software using the packages ''metagear'' and ''revtool.'' We reviewed and analyzed a total of 53 articles published between 1994 and 2024. The literature review covered studies from 29 countries, represented by six continents, namely, Africa, Asia, Europe, North America, Oceania, and South America, with the majority of the studies from Asia. R. rattus had the most published studies. Our literature review identified 87 species of zoonotic ectoparasites, with Xenopsylla cheopis, Polyplax spinulosa, and Laelaps echidninus being the most reported across all host species. Mites were the most reported ectoparasites (40.83%), followed by fleas (25%), ticks (20%), and lice (14.17%). Most of these ectoparasites were reported from R. rattus, with the highest number of documented ectoparasites. Investigating the prevalence, distribution, and potential risks of alien invasive rodents and their ectoparasites is paramount for public health and improving integrated pest management control strategies.

Prevalence and novel genetic characteristics of Cryptosporidium spp. in wild rodents in the northern foothills of the Dabie Mountains, southeast Henan Province, China

BACKGROUND

Cryptosporidium spp. are prevalent zoonotic pathogens that affect both humans and animals. The pathogens are spread through feces and represent a major cause of diarrhea. As they are both abundant and widely distributed, wild rodents play a significant role in the transmission of Cryptosporidium spp. The Dabie Mountains in southeast Henan Province are rich in wildlife resources as well as various species of livestock. However, the epidemiological characteristics of Cryptosporidium spp. among local wild rodents remain poorly understood. Therefore, the infection rate and genetic characteristics of Cryptosporidium spp. in wild rodents within this region should be determined.

METHODS

Between March 2023 and April 2024, a total of 267 wild rodents were captured in the northern foothills of the Dabie Mountains, and fecal samples were collected from their intestines for DNA extraction. Species identification of wild rodents was conducted using PCR amplification of the universal vertebrate cytochrome b (cytb) gene. Nested PCR was subsequently used to amplify the small subunit (SSU) rRNA, actin, heat shock protein 70 (HSP70), and 60 kDa glycoprotein (gp60) genes for the analysis of Cryptosporidium species, genotypes, and subtypes in the fecal samples.

RESULTS

The infection rate of Cryptosporidium spp. in wild rodents from the northern foothills of the Dabie Mountains was 21.3% (57/267). Seven species of wild rodents were identified, and the infection rates for Cryptosporidium spp. varied among host species. In particular, the infection rate was 21.4% (25/117) in Niviventer lotipes, 22.4% (22/98) in Apodemus agrarius, 17.2% (5/29) in Rattus nitidus, 22.2% (4/18) in Apodemus draco, and 33.3% (1/3) in Rattus tanezumi. The identification results indicated the presence of five Cryptosporidium species: Cryptosporidium apodemi (n = 12), C. ubiquitum (n = 11), C. viatorum (n = 7), C. ratti (n = 2), and C. occultus (n = 2). Moreover, two novel genotypes were identified: Cryptosporidium sp. rat genotype VI (n = 8) and Cryptosporidium sp. rat genotype VII (n = 15). Notably, a new subtype of C. viatorum designated as XVgA4 was discovered.

CONCLUSIONS

This study revealed the prevalence of Cryptosporidium spp. in wild rodents in the northern foothills of the Dabie Mountains and identified two novel Cryptosporidium genotypes, along with a new subtype, C. viatorum-XVgA4. The findings highlight the genetic diversity of Cryptosporidium spp., underscoring the increased risk of Cryptosporidium spp. transmission posed by local wild rodents population. It suggests that host-specific factors should be considered in epidemiological surveillance and control strategies of Cryptosporidium spp., which is of great significance for the prevention and control of Cryptosporidiosis.

Waterborne protozoan and microsporidian parasites in Eurasian beavers (Castor fiber)

The Eurasian beaver (Castor fiber) is an expanding species in Europe in recent decades due to reintroductions and natural population growth. Beavers expanded rapidly in the second half of the 20th century, and their expansion was particularly rapid in the Danube basin. Nowadays, the majority of the continuous population located in the central and eastern parts of the continent and a large disjunct population in Norway and Sweden. Despite the increasing population size, the role of the beaver as a source of waterborne pathogens is not firmly established or is often inferred from circumstantial data. In order to extend knowledge about the composition of the parasite fauna of beavers occurring in Slovakia, 21 faecal samples taken near their burrows from three sites (located in the Topľa, Poprad and Danube river basin) were examined microscopically and by polymerase chain reaction (PCR). PCR-positive specimens were further examined by DNA sequencing. Parasites were detected in 21% of the examined beavers, specifically the protozoa Cryptosporidium spp. (n = 2), Blastocystis sp. (n = 1), and microsporidia Enterocytozoon bieneusi (n = 1) and Encephalitozoon spp. (n = 1). Using the sequence analysis, two variants of Cryptosporidium proliferans, a new subtype of Blastocystis sp., genotype D of E. bieneusi and Encephalitozoon intestinalis were identified. A putatively novel Blastocystis subtype (ST), originated from a site near the Danube river (southwestern Slovakia), was proposed based on high genetic divergence from the closest described subtype ST12 (11.9%) and unique phylogenetic position in a clade composed of ST's 35-38. The increased risk of zoonotic transmission or transmission to other animals was particularly evident in the site near the Topľa river (northeastern Slovakia), where fungal spores of zoonotic genotype D of E. bieneusi and E. intestinalis, together with oocysts of the potentially zoonotic C. proliferans, were found.

Genetic diversity of Enterocytozoon bieneusi in 1099 wild animals and 273 imported pastured donkeys in northern China

BACKGROUND

Enterocytozoon bieneusi is the most frequently detected microsporidian species in humans, wildlife and domestic animals. In northern China, to the best of our knowledge, no information on E. bieneusi infection has been reported in wild animals. The aim of the present study was to survey the occurrence of and genetically characterize E. bieneusi from a broad spectrum of vertebrate species in this region.

METHODS

A total of 1372 small intestine or fecal specimens were collected from 1019 mammals, 121 reptiles and 232 birds in Xinjiang Uygur Autonomous Region (XUAR) and Inner Mongolia Autonomous Region (IMAR), northern China. Each animal species was identified according to morphological characteristics and amplification of mitochondrial genes. Genotype analysis of E. bieneusi was performed by amplifying the internal transcribed spacer (ITS) region.

RESULTS

A total of 68 wild animal species were identified, including 34 mammal species, six reptile species and 28 bird species. The average rate of infection with E. bieneusi was 9.7% (133/1372 specimens). Twelve genotypes of E. bieneusi, including BEB6, CHG7, D, E, EbpD, horse1, MWC_d1, NCF2, NCF6, PL14, SN45 and XJHT4, were identified in specimens from XUAR, IMAR and Kyrgyzstan. Phylogenetically, these genotypes belonged to four groups, namely Group 1, Group 2, Group 12 and Group 14.

CONCLUSIONS

To our knowledge, this study reports for the first time E. bieneusi genotype NCF2 in marbled polecats (Vormela peregusna), genotype NCF6 in red foxes (Vulpes vulpes), genotype D in grey wolf (Canis lupus), genotypes CHG7, horse1 and PL14 in rodents and genotypes MWC_d1, PL14 and SN45 in wild birds. The results also indicate that genotypes horse1, NCF2 and NCF6 were acquired either by the fecal-oral transmission route or during predator-prey interaction.

Prevalence and genotype analysis of Cryptosporidium spp. in nine species of wild rodents in China

Cryptosporidium is a significant zoonotic parasite with broad distribution in both humans and rodents. In this study, 510 fecal samples were collected from nine species of wild rodents across Guangxi, Yunnan, and Hunan Provinces in China. Nested PCR analysis targeting the SSU rRNA gene revealed an overall Cryptosporidium infection rate of 1.8% (9/510) among rodents in these provinces. The highest positivity rate was observed in Guangxi Province at 4.9% (5/103), followed by Yunnan Province (2.3%, 2/88), and Hunan Province (0.6%, 2/319). Notably, Rattus losea exhibited the highest prevalence rate at 9.8% (4/41), while Rattus flavipectus and Niviventer lotipes showed rates of 5.1% (2/39) and 4.4% (1/23), respectively. Various genotypes/species were identified, including Cryptosporidium viatorum, Cryptosporidium muris, Cryptosporidium vole genotype VII, and Cryptosporidium ratti, rat genotypes II, and IV. The study also found that wild rodents inhabiting mountainous areas had a higher prevalence rate at 4.9% (5/103) compared to those residing in fields and lake beaches, where prevalence rates were 2.1% (2/95) and 0.6% (2/312), respectively. This study provides new insights into Cryptosporidium infection rates among wild rodents and identifies two zoonotic species, C. viatorum and C. muris. These findings underscore the potential risk posed by Chinese wild rodent populations in transmitting zoonotic Cryptosporidium, which could significantly impact public health. Therefore, effective control strategies are needed to prevent transmission between humans and rodents.

Deciphering Host-Pathogen Interactions: Role of Cryptosporidium in Tumorigenesis

Cryptosporidium, a protozoan parasite affecting the gastrointestinal system, is primarily known for causing diarrhea, especially in those with weakened immune systems. However, there is increasingly persuasive evidence that it may be directly involved in tumorigenesis. This review examines some of the potential mechanisms through which Cryptosporidium infections can induce cancer, specifically chronic inflammation, manipulation of the immune system, and alteration of cell signaling pathways. Persistent inflammation with immune system changes due to chronic infection, particularly among immunocompromised hosts, leads to a microenvironment that facilitates tumorigenesis. Cryptosporidium manipulates important cellular pathways such as PI3K, NF-κB, Wnt, and p38/MAPK to promote cell survival, regulate immune responses, and foster tissue remodeling, all of which contribute to a tumor-friendly microenvironment. Moreover, Cryptosporidium virulence factors such as ROP1, sPLA2, and microRNAs disrupt host cellular stability and significantly alter host cellular gene expression, which also exacerbates inflammation and tissue damage. Epidemiological data have indicated higher rates of Cryptosporidium infection in cancer patients, especially patients with gastrointestinal cancers. This, among other observations, raises the possibility that the infection may be connected to cancer progression. In animal models, especially studies with C. parvum-challenged rodents, chronic inflammation, immune repression, and genetic mutations related to neoplasia have been reported. While this has provided us with valuable information, we still have a long way to go to fully understand the long-term ramifications of Cryptosporidium infection. These cover aspects such as the contribution of latent infections and the genetic diversity of Cryptosporidium strains in cancer. Further investigation is urgently needed to understand the molecular processes by which Cryptosporidium might contribute to carcinogenesis and explore potential strategies for therapy and prevention especially among immunocompromised populations.

First microscopic and molecular identification of Cryptosporidium spp. in fat sand rats (Psammomys obesus) in Egypt and their potential zoonotic implications

Introduction

Rodents, thriving in human-altered environments, pose significant public health risks due to their role as reservoirs for numerous zoonotic parasites. Among these, Cryptosporidium spp. are recognized globally as leading causes of waterborne and foodborne diarrheal illnesses in humans. The specific role of fat sand rats (Psammomys obesus) in the transmission of Cryptosporidium spp. in Egypt and the genotypic characteristics of the circulating species in these animals remain poorly understood.

Methods

In this study, a total of 150 individual fat sand rat stool samples were collected from the saline marsh periurban areas of Abu-Rawash, Giza, Egypt. The samples were initially screened for the presence of Cryptosporidium spp. using light and scanning electron microscopy to characterize the parasite's oocysts. Furthermore, molecular identification and characterization of the parasite were carried out on selected microscopy-positive samples (n = 30) using conventional polymerase chain reaction (PCR) targeting the Cryptosporidium oocyst wall protein (COWP) gene. A subset of these positive samples by PCR was subjected to sequencing, with the resulting sequences deposited in GenBank™ and analyzed through phylogenetic methods.

Results

Conventional microscopy revealed that 46.7% (70/150; 95% CI: 38.7-54.6) of the analyzed stool samples contained structures consistent with Cryptosporidium oocysts. Moreover, the molecular analysis confirmed Cryptosporidium species in DNA from all 30 stool samples previously identified as heavily infected through microscopy. Notably, the phylogenetic analysis identified Cryptosporidium parvum (C. parvum) in the sequenced samples, likely originating from the rats' native habitats. These identified species have been deposited in GenBank™ under the accession numbers OM817461 (C. parvum FSA-1), OM817462 (C. parvum FSA-2), and OM817463 (C. parvum FSA-3) and revealed closed genetic identity with those species reported from human and other animal species in the same geographic location.

Conclusion

Overall, this study represents the first morphological and genetic identification of C. parvum isolated from fecal samples of fat sand rats trapped from periurban areas in Egypt. These findings provide valuable insights into the potential zoonotic implications of rodents in disease transmission at the national level, offering crucial information for public health awareness campaigns and informing local authorities.

Research and characterization of Cryptosporidium spp. in the domestic cat (Felis catus): First description of C. felis in the state of Goiás and C. muris in the Midwest region of Brazil

With the increasingly close coexistence between pets and humans, coupled with reports of Cryptosporidium cross-infection between felines and their guardians, research aimed at understanding the epidemiology of these parasites in specific regions has become necessary. The principal objective of this study was to undertake a molecular characterization of Cryptosporidium in fecal samples from felines in the state of Goiás, Brazil (which is unprecedented for the region), and to assess the risk factors involved in the infection of these animals in the aforementioned locale. A total of 95 fecal samples were collected from domestic felines in the municipality of Goiânia, Goiás, Brazil. All the animals involved were categorized by sex (male or female), lifestyle (stray or domiciled), and age (under six months or six months and older). After collection, all fecal aliquots underwent genomic DNA extraction, followed by a nested PCR (nPCR) technique targeting the 18 s rRNA gene. Subsequently, sequencing of all amplified products was performed to diagnose Cryptosporidium parasites. In addition to searching for Cryptosporidium in feces, all felines underwent serological testing for Feline Immunodeficiency Virus (FIV) antibodies (IgG) using the Enzyme-Linked Immunosorbent Assay (ELISA). Of all the fecal samples analyzed, 17.9 % (17/95) tested positive for the presence of Cryptosporidium spp. DNA, with the variable "age under six months" being the only statistically significant risk factor (p ≤ 0.05) for feline infection. C. felis was the most prevalent species, identified in 88.2 % (15/17) of the positive samples. C. muris was the second most diagnosed species, confirmed in 5.9 % (1/17) of the positive samples. Of all the feline serological samples evaluated, 48.42 % (46/95) were positive for anti-FIV IgG. It was confirmed that 75 % (3/4) of all adult animals positive for Cryptosporidium showed positive (50.00 % [2/4]) or indeterminate (25.00 % [1/4]) results for FIV. This unprecedented study provides the first report of parasites from the genus Cryptosporidium in domestic felines in the state of Goiás, including the first report of C. felis in the state and of C. muris in Midwest Brazil.

Identification of a novel GP60 subtype family of Cryptosporidium wrairi from capybaras (Hydrochoerus hydrochaeris) inhabiting urban areas in the state of Mato Grosso do Sul, Brazil

Capybaras (Hydrochoerus hydrochaeris) are hosts for several parasites of public health importance, including Cryptosporidium spp. Therefore, this study aimed to perform the molecular characterization of Cryptosporidium spp. in fecal samples from capybaras inhabiting urban areas. We analyzed 401 fecal samples from capybaras in two municipalities of the state of Mato Grosso do Sul, Brazil. Fecal samples were purified using centrifugal sedimentation with ethyl acetate. They were then screened for Cryptosporidium spp. by malachite green negative staining and a nested PCR protocol targeting the 18S rRNA gene. Samples positive by microscopy or PCR were examined by PCR protocols targeting the actin, HSP-70, and GP60 genes. Amplicons from all PCR protocols were subjected to genetic sequencing. Microscopic screening and 18S rRNA gene-targeted PCR identified 0.25 % (1/401) and 0.5 % (2/401) of samples, respectively, as positive for Cryptosporidium spp. The genetic sequences of the 18S rRNA, HSP-70, actin, and GP60 genes showed genetic similarity to Cryptosporidium wrairi sequences of 99.07 %, 99.69 %, 99.57 %, and 91.51 %, respectively. Genetic sequencing and phylogenetic analyses identified the novel GP60 subtype family VIIbA13 of C. wrairi. In conclusion, we report in this study a low prevalence of the novel GP60 subtype family VIIbA13 of C. wrairi in free-living capybaras from urban areas of the state of Mato Grosso do Sul, Brazil. We propose that capybaras act as a novel host for C. wrairi.

Molecular identification and subtyping of Cryptosporidium spp. in laboratory mice and rats

Cryptosporidium species can infect humans and more than 260 animal species, including 54 rodent species. However, data on the occurrence and genetic characterizations of Cryptosporidium spp. in laboratory rodents are limited. The present study aimed to determine the occurrence rate and genetic characterizations of Cryptosporidium spp. in laboratory mice and rats. We collected 506 fresh combined fecal pellet specimens (457 from mice and 49 from rats) of more than 2,000 laboratory rodents in Heilongjiang Province and Shanghai City, China. Cryptosporidium spp. were identified and subtyped by DNA sequencing of the SSU rRNA and the gp60 genes, respectively. By sequence analysis of the SSU rRNA gene, the occurrence rate of Cryptosporidium spp. was 16.6% (84/506) in combined fecal specimens, with 18.2% (83/457) for mice and 2.0% (1/49) for rats. Cryptosporidium parvum (n = 39), C. tyzzeri (n = 33), and C. parvum + C. tyzzeri (n = 11) were identified in mice. Cryptosporidium parvum was only detected in one rat fecal specimen. At the gp60 locus, 71.4% (60/84) of the Cryptosporidium-positive specimens were successfully amplified, and they all came from mice. We identified five C. parvum subtypes (IIaA14G2R1, IIaA16G2R1, IIaA17G1R1, IIaA17G2R1, and IIaA18G2R1) and two C. tyzzeri subtypes (IXaA6R1 and IXbA8). Based on the identification in laboratory mice of C. parvum subtypes that have been reported previously in humans, the mice infected with this species may threaten human health, especially for people who have contact with the animals and their feces.

Occurrence of multiple infections of rodents with parasites and bacteria in the Sibang Arboretum, Libreville, Gabon

Background and Aim

Rodents are carriers or reservoirs of various bacteria, protozoa, viruses, and ectoparasites. Given the proximity of various rodent species and humans, there is a potential for the transmission of pathogens. Data on ecto- and endo-parasite prevalence in rodent populations in Gabon are limited. To fill this gap, we conducted a study in Libreville to investigate the occurrence of ecto- and endo-parasites in rodents.

Materials and Methods

We captured and euthanized 68 rodents belonging to the genus Praomys and examined their ecto- and endo-parasite fauna, dissected their gastrointestinal tract for helminths, and prepared blood smears to examine blood-borne pathogens.

Results

Our analyses identified three pathogen taxa: helminths (Protospirura spp., Trichuris spp., and Taenia spp.), protozoa (Babesia spp.), bacteria (Anaplasma spp.), and arthropods (Laelaps and Haemaphysalis). Overall, 91.2% of the rodents were infected with at least one pathogen and ectoparasite, with helminth occurrence rate of 63.2% and ectoparasite occurrence at 44.1%. Protozoan infections (Babesia spp.) were found in 10.3% of the rodents, whereas bacteria (Anaplasma spp.) had an occurrence rate of 39.7%.

Conclusion

Native rodents in Libreville harbor various infectious agents, ecto- andendo-parasites. These findings highlight the potential health risks associated with Praomys rodents for the transmission of various diseases to human population in Gabon and emphasize the need for investigation of rodents for their role as disease carriers.

Occurrence rate and species and subtypes of Cryptosporidium spp. in pet dogs in Yunnan Province, China

BACKGROUND

Cryptosporidium spp. is a ubiquitous, globally distributed intestinal protozoan infecting humans and at least 260 animal hosts. Due to close human contact with pet dogs and identification of zoonotic Cryptosporidium species and subtypes in these animals, dog health is not only a veterinarian issue but also a public health issue. This study aimed to understand occurrence and genetic characterization at both genotype and subtype levels in pet dogs in Yunnan Province, China.

RESULTS

A total of 589 fresh fecal specimens were collected from adult pet dogs in the rural areas of eight cities/autonomous prefectures of Yunnan Province, China. 16 fecal specimens were positive for Cryptosporidium spp. by polymerase chain reaction (PCR) amplification and sequence analysis of the small subunit ribosomal RNA (SSU rRNA) gene, with an average occurrence rate of 2.7% (16/589) being observed. Three zoonotic Cryptosporidium species were identified: C. parvum (n = 7), C. suis (n = 5) and C. canis (n = 4). At the 60-kDa glycoprotein (gp60) locus, only three C. parvum and two C. canis specimens were successfully amplified and sequenced, with subtype IIaA17G2R1 (n = 3) and subtypes XXa4 (n = 1) and XXa5 (n = 1) being identified, respectively.

CONCLUSIONS

The present finding of three zoonotic Cryptosporidium species in dogs implied that dogs infected with Cryptosporidium spp. may pose a threat to human health. C. suis was identified in dogs in this study for the first time, expanding the host range of this species. Identification of C. parvum subtype IIaA17G2R1 and C. canis subtypes XXa4 and XXa5 will be helpful to explore the source attribution of infection/contamination and assess the transmission dynamics of C. parvum and C. canis in the investigated areas in the future.

A molecular survey of zoonotic pathogens of public health importance in rodents/shrews and their ectoparasites trapped in Puducherry, India

BACKGROUND

Globally, India has a high zoonotic disease burden and lacks surveillance data in humans and animals. Rodents are known reservoirs for many zoonotic diseases and their synanthropic behavior poses a great public health threat.

METHODS

In this study, trapped rodents/shrews from randomly selected villages within Puducherry, India, and their ectoparasites were screened for zoonotic pathogens, namely, Orientia tsutsugamushi, other pathogenic rickettsiae, Leptospira spp., Cryptosporidium spp., Coxiella burnetii and methicillin-resistant Staphylococcus aureus (MRSA) using conventional PCR. A total of 58 rodents/shrews were trapped from 11 villages. The species trapped were Suncus murinus (49/58, 84.48%), Rattus rattus (8/58, 13.79%) and Rattus norvegicus (1/58, 1.72%). All ectoparasites collected were identified as mites and its infestation rate was 46.55% (27/58).

RESULTS

Real-time PCR targeting the 47 kDa gene of O. tsutsugamushi revealed positivity in one rodent and one shrew (3.45%) and two mite pools (7.41%). Conventional PCR targeting the 56 kDa gene revealed positivity in one shrew and two mite pools and the phylogenetic analysis of all three amplicons indicated the circulation of the Gilliam-related serotype. MRSA was detected in the alimentary tract of a shrew (1/32, 3.13%). Leptospira spp., Rickettsia, Cryptosporidium spp. and Co. burnetii tested negative.

CONCLUSIONS

The detection of zoonotic pathogens within reservoir hosts and vectors poses a risk of transmission to humans. This study signifies the need for zoonotic pathogen surveillance in synanthropic rodents/shrews.

Molecular detection of Cryptosporidium parvum in wild rodents (Phyllotis darwini) inhabiting protected and rural transitional areas in north-central Chile

Wild rodents often harbor Cryptosporidium species that can be transmitted to multiple mammal hosts. In Chile, little is known about Cryptosporidium in wild rodents, and available studies have been focused on morphological findings with no molecular-based evidence. A longitudinal survey was conducted between 2021 and 2022 to investigate the occurrence of Cryptosporidium spp. in populations of the Darwin's leaf-eared mouse (Phyllotis darwini) living in protected and rural transitional areas in north-central Chile, using staining and molecular methods. A total of 247 fecal samples were collected and examined by the modified Ziehl-Neelsen (ZN) staining test, 54 of which were positive for Cryptosporidium-like oocysts. Molecular analyses were carried out by PCR of the partial 18S ribosomal RNA and 60 kDa glycoprotein (gp60) genes. Cryptosporidium infection was confirmed in 34 samples (13.7 %) based on the PCR amplification, and individual (i.e., sex, and body mass index) and ecological variables (i.e., type of site and season) were not statistically significant (p > 0.05). Using the nucleotide sequencing of the partial 18S rRNA gene, Cryptosporidium parvum was identified in nine isolates. Also, C. parvum subgenotype family IIa was determined in seven samples by the partial gp60 gene, including the subtype IIaA17G4R1 in two samples. This is the first molecular evidence of Cryptosporidium parvum IIa in Phyllotis darwini in Chile. These results indicate potential cross-species transmition between wild rodents and domestic-wild animals in north-central Chile. More research is needed to understand better the role of wild rodents in the transmission of Cryptosporidium spp. in Chile.

Detection of Trypanosoma lewisi from rodents residing in the densely populated residential regions along the coastal areas of Banyuwangi Sub District, Indonesia

Background

Extensive attention has been devoted to studies of Trypanosoma lewisi in rodents ever since it became recognised as a zoonotic pathogen known as atypical human trypanosomiasis. Regrettably, although T. lewisi infections of small mammals remain significant public health concerns for humans, there is a lack of comprehensive study in Indonesia.

Aim

The aim of the study was to detect T. lewisi from rodents residing in the densely populated residential regions along the coastal areas of Banyuwangi Sub District.

Methods

A total of 169 rodents were captured across three villages of Kampung Mandar, Lateng and Kepatihan, using rat single live traps. After being euthanized and identified, the blood samples were collected from each rodent via cardiac puncture. Subsequently, the samples were subjected to native (direct blood microscopic examination), microscopic blood smear examination, and molecular analyses utilizing TRYP1S-TRYP1R (623 bp) and LEW1S-LEW1R (220 bp).

Results

The results demonstrated that two species of rodents were successfully captured: Rattus norvegicus (65.68%) and Rattus tanezumi (34.32%). Based on the native and microscopic blood smear examinations, the prevalence of T. lewisi across three villages was 23.08% and 24.26% for molecular analysis employing both primers, respectively. The highest prevalence was found in Kampung Mandar Village (31.18%), followed by Kepatihan (16.67%) and Lateng Villages (15.71%).

Conclusion

Statistical analysis revealed that T. lewisi was more prevalent in R. tanezumi compared to R. norvegicus. In terms of sex, no statistically significant distinction was observed between female and male infected rodents of either species (p > 0.05), indicating both species can serve as a source of T. lewisi for humans in the surveyed villages.

Molecular characterizations of Cryptosporidium spp. in brown rat (Rattus norvegicus) from an animal feedlot in Xinjiang, China

Cryptosporidium infection is a common occurrence in rodents worldwide. In this study, 435 wild brown rats were captured from an animal feedlot in Xinjiang, China, with a fecal sample obtained directly from the rectal contents of each rat. The DNA extracted from these fecal samples was analyzed for Cryptosporidium spp. using PCR targeting the SSU rRNA gene. The prevalence of Cryptosporidium infection in brown rats was found to be 5.5% (24 out of 435). Interestingly, the infection rates varied among different animal enclosures, with rates of 0% in the chicken coop (0/51), cowshed (0/3), and varying rates in other areas including the sheepfold (6.1%, 6/98), the pigsty (7.6%, 10/132), the dovecote (7.0%, 5/71), and outdoor environments (3.8%, 3/80). The study identified three species and one genotype of Cryptosporidium, namely C. occultus (n = 10), C. parvum (n = 4), C. ditrichi (n = 1), and Cryptosporidium rat genotype IV (n = 9). Additionally, two of the C. parvum isolates were successfully subtyped as IIdA19G1 (n = 2) at the gp60 gene. These results offer valuable insights into the prevalence and genetic diversity of Cryptosporidium in brown rats within the region.

Prevalence of Cryptosporidium spp. infection in rodents and chickens in Franceville, Gabon

Background and Aim

Cryptosporidium spp. members of the phylum Apicomplexa are obligate protozoan parasites capable of infecting various vertebrate hosts, including rodents and chickens. Infection caused by these parasites may lead to zoonotic diseases in humans. The aim of this study was to estimate the prevalence of Cryptosporidium spp. in rodents and domestic chickens sampled in Franceville, Gabon.

Materials and Methods

Two hundred and eighty-five samples were collected, of which 185 samples were from rodents and 100 from domestic chickens. Microscopy after modified Ziehl-Neelsen staining and nested polymerase chain reaction targeting the small subunit (SSU) rRNA gene were used to examine Cryptosporidium spp.

Results

The overall prevalence of Cryptosporidium oocysts was 55.8%, with a prevalence of 72.4% in rodents and 25.0% in domestic chickens. Molecular analysis showed that Cryptosporidium spp. were present in 4.0% of the samples. No significant correlation was observed between Cryptosporidium spp. carriage and sex or location in this study. These results indicate that Cryptosporidium spp. persist and circulate in the studied animal species in Franceville, Gabon.

Conclusion

Infection with Cryptosporidium is very common in rodents and chickens in Franceville. The potential risk of human contamination cannot be ruled out. More research should be conducted to characterize Cryptosporidium species circulating in rodents and chickens in Gabon. Such studies are essential to better understand the epidemiology of this protozoan and its potential impact on public health.

Cross-species transmission of Cryptosporidium in wild rodents from the southern region of Zhejiang Province of China and its possible impact on public health

Wild rodents serve as reservoirs for Cryptosporidium and are overpopulated globally. However, genetic data regarding Cryptosporidium in these animals from China are limited. Here, we have determined the prevalence and genetic characteristics of Cryptosporidium among 370 wild rodents captured from three distinct locations in the southern region of Zhejiang Province, China. Fresh feces were collected from the rectum of each rodent, and DNA was extracted from them. The rodent species was identified by PCR amplifying the vertebrate cytochrome b gene. Cryptosporidium was detected by PCR amplification and amplicon sequencing the small subunit of ribosomal RNA gene. Positive samples of C. viatorum and C. parvum were further subtyped by analyzing the 60-kDa glycoprotein gene. A positive Cryptosporidium result was found in 7% (26/370) of samples, involving five rodent species: Apodemus agrarius (36), Niviventer niviventer (75), Rattus losea (18), R. norvegicus (155), and R. tanezumi (86). Their respective Cryptosporidium positive rates were 8.3%, 5.3%, 11.1%, 7.1%, and 7.0%. Sequence analysis confirmed the presence of three Cryptosporidium species: C. parvum (4), C. viatorum (1), and C. muris (1), and two genotypes: Cryptosporidium rat genotype IV (16) and C. mortiferum-like (4). Additionally, two subtypes of C. parvum (IIdA15G1 and IIpA19) and one subtype of C. viatorum (XVdA3) were detected. These results demonstrate that various wild rodent species in Zhejiang were concurrently infected with rodent-adapted and zoonotic species/genotypes of Cryptosporidium, indicating that these rodents can play a role in maintaining and dispersing this parasite into the environment and other hosts, including humans.

Molecular characterization of Cryptosporidium spp. in Bactrian camels (Camelus bactrianus) from Yili Kazak Autonomous Prefecture of Xinjiang, China

Introduction

Cryptosporidium spp. is a significant zoonotic parasite. The prevalence and infection characteristics of Cryptosporidium spp. in Bactrian camels in Yili Kazak Autonomous Prefecture have yet to be fully understood. Thus, the molecular epidemiology of cryptosporidiosis in camels was investigated in this region.

Methods

A total of 1,455 fecal samples were collected from 6 counties in three regions (Altay, Tacheng, and Yili) in Yili Prefecture. Nested PCR targeting the small subunit ribosomal RNA (ssu rRNA) gene was used to identify the species or genotypes of Cryptosporidium infection in camels. For C. parvum positive samples, the subtypes were identified using the 60-kDa glycoprotein (gp60) gene.

Results and discussion

The overall infection rate was 8.7% (126/1,455), ranging from 5.6% to 11.7% in different regions, and 4.2% to 15.8% in different counties. A significant difference was observed amongst the counties (p < 0.001). Three species were detected, namely C. andersoni (65.1%, 82/126), C. parvum (34.1%, 43/126), and C. occultus (0.8%, 1/126). Three C. parvum subtypes, If-like-A15G2 (n = 29), IIdA15G1 (n = 4), and IIdA19G1(n = 1) were detected, with If-like-A15G2 being the most prevalent subtype. Camels aged 3-12 months exhibited the highest infection rate (11.4%, 44/387), with no significant difference among age groups (p > 0.05). C. parvum was predominant in camels under 3 months, while C. andersoni prevailed in camels over 3 months. There was an extremely significant difference observed among seasons (p < 0.001), summer had the highest infection rates (16.9%, 61/360). This study collected nearly 1,500 samples and, for the first time, investigated Cryptosporidium spp. infection in camels based on different age groups and seasons. All three Cryptosporidiumspecies identified were zoonotic, posing a potential threat to human health and requiring close attention.

Molecular characterization of Cryptosporidium spp., Giardia spp. and Enterocytozoon bieneusi in eleven wild rodent species in China: Common distribution, extensive genetic diversity and high zoonotic potential

Cryptosporidium spp., Giardia spp. and Enterocytozoon bieneusi are common zoonotic pathogens in humans and animals. Although rodents are important parts of the ecosystem and common hosts for these pathogens, little is known of the distribution, genetic diversity and zoonotic potential of these pathogens in wild rodents. A total of 442 fecal samples were collected from eleven wild rodent species in three provinces of China, and analyzed for these pathogens by PCR and DNA sequencing. The infection rates of Cryptosporidium spp., Giardia spp. and E. bieneusi were 19.9% (88/442), 19.8% (75/378) and 12.2% (54/442), respectively. Altogether, 23 known Cryptosporidium species/genotypes were identified and their distribution varied among different sampling locations or rodent species. Subtyping of the zoonotic Cryptosporidium species identified two novel subtype families XVe and XVf in C. viatorum, the subtype family XIIh and a novel subtype family XIIj in C. ubiquitum, and the subtype family IId in C. parvum. Three Giardia species were identified, including G. microti (n = 57), G. muris (n = 15) and G. duodenalis (n = 3), with G. duodenalis assemblages A and G identified in brown rats in urban areas of Guangdong. In addition, 13 E. bieneusi genotypes including eight known and five novel ones were identified, belonging to Groups 1, 2, 10, 14 and 15. Within nine genotypes in the zoonotic Group 1, common human-pathogenic genotypes D, Type IV, PigEbITS7 and Peru8 were detected only in brown rats and Lesser rice-field rats in urban areas of Guangdong. Apparent host adaptation and geographical differences were observed among Cryptosporidium spp., Giardia spp. and E. bieneusi genotypes in wild rodents in the present study. Furthermore, the zoonotic Cryptosporidium species and E. bieneusi genotypes commonly found here suggest a high zoonotic potential of these pathogens in wild rodents, especially in brown rats in urban areas. Hygiene and One Health measures should be implemented in urban streets and food stores to reduce the possible direct and indirect transmission of these rodent-related pathogens.

Molecular characterization of Cryptosporidium in wild rodents from the Inner Mongolian Autonomous Region and Liaoning Province, China: assessing host specificity and the potential for zoonotic transmission

Introduction

Wild rodents are key hosts for Cryptosporidium transmission, yet there is a dearth of information regarding their infection status in the Inner Mongolian Autonomous Region and Liaoning Province of China. Therefore, the present study was conducted to determine the prevalence and genetic characteristics of Cryptosporidium among wild rodents residing in these two provinces.

Methods

A total of 486 rodents were captured, and fresh feces were collected from each rodent's intestine for DNA extraction. Species identification of rodents was performed through PCR amplification of the vertebrate cytochrome b (cytb) gene. To detect the presence of Cryptosporidium in all fecal samples, PCR analysis and sequencing of the partial small subunit of the ribosomal RNA (rRNA) gene were performed.

Results

Four species of rodents were identified: Rattus norvegicus, Mus musculus, Apodemus agrarius, and Cricetulus barabensis. Positive results for Cryptosporidium were obtained for 9.2% (18/195), 6.6% (7/106), 5.6% (5/89), and 6.3% (6/96) of these rodents, respectively, with an average infection rate of 7.4% (36/486). The identification revealed the presence of five Cryptosporidium species, C. ubiquitum (n = 8), C. occultus (n = 5), C. muris (n = 2), C. viatorum (n = 1), and C. ratti (n = 1), along with two Cryptosporidium genotypes: Rat genotype III (n = 10) and Rat genotype IV (n = 9).

Discussion

Based on the molecular evidence presented, the wild rodents investigated were concurrently infected with zoonotic (C. muris, C. occultus, C. ubiquitum and C. viatorum) as well as rodent-adapted (C. ratti and Rat genotype III and IV) species/genotypes, actively participating in the transmission of cryptosporidiosis.

Detection of zoonotic Cryptosporidium spp. in small wild rodents using amplicon-based next-generation sequencing

Rodents may serve as reservoirs of zoonotic species of Cryptosporidium; however, data from molecular surveys in support of this hypothesis are still scarce. In this study, we screened faeces and rectal content from murid and cricetid rodents (N = 58) caught around three farms in Zealand, Denmark, for Cryptosporidium spp. by amplicon-based next-generation sequencing (NGS) of ribosomal genes. Selected samples were further examined using nested conventional PCR targeting SSU rRNA, gp60, and actin genes. Cryptosporidium-specific DNA was identified in 40/58 (69%) samples, and in 12 (30%) of the 40 positive animals, mixed cryptosporidial infections were observed. Cryptosporidium ditrichi was the species most commonly identified, found in 28 (48%) of the animals. Cryptosporidium parvum was identified in 4 (7%) of the animals, all of which were co-infected with C. ditrichi. The present study is the first to utilize NGS-based screening for Cryptosporidium species in wild rodents. Moreover, it is the first study to provide molecular data on Cryptosporidium in rodents sampled in Denmark and to detect DNA of C. ditrichi in Mus musculus, Myodes glareolus, and Microtus agrestis. The NGS approach was successfully applied to yield new knowledge, and the results showed that zoonotic species of Cryptosporidium are common in murid and cricetid rodents in Zealand, Denmark.

Study on genetic characteristics of Cryptosporidium isolates and first report of C. parvum IIdA24G2 subtype in dairy cattle in China

Cryptosporidium is an important gastrointestinal parasite that can cause mild to severe diarrhea in various vertebrates, including humans and domestic animals. Infection is prevalent in dairy cattle, particularly calves, resulting in diarrhea and increased mortality with significant production losses. However, the prevalence and identity of Cryptosporidium spp. in cattle in Heilongjiang Province is still poorly known. Our study aimed to investigate the prevalence and species and subtype distribution of Cryptosporidium in cattle in the region. In addition, we evaluated the zoonotic potential of Cryptosporidium isolates and assessed possible transmission routes and health effects of this organism. We collected 909 fecal samples from five different farms in Heilongjiang Province between August and September 2022. The samples underwent Cryptosporidium detection by nested PCR and small subunit (SSU) rRNA gene sequence analysis. Four Cryptosporidium species were identified, including C. parvum, C. bovis, C. ryanae, and C. andersoni, with an overall prevalence of 4.4% (40/909). Based on sequence analysis of the 60 kDa glycoprotein gene of C. parvum and C. bovis, three subtypes of C. parvum were identified, namely two previously known subtypes (IIdA19G1 and IIdA20G1), and one novel subtype (IIdA24G2). Two distinct subtype families were identified in C. bovis (XXVId and XXVIe). The high diversity of Cryptosporidium in dairy cattle and the emergence of a novel subtype of C. parvum in Heilongjiang Province suggest that dairy cattle may serve as a significant source of zoonotic cryptosporidiosis infection in this region.

Micro-RNA expression profile of BALB/c mouse glandular stomach in the early phase of Cryptosporidium muris infection

Cryptosporidiosis is a zoonotic disease in humans and animals that is caused by infection with the oocysts of Cryptosporidium. MicroRNAs (miRNAs) are important players in regulating the innate immune response against parasitic infection. Public miRNAs data for studying pathogenic mechanisms of cryptosporidiosis, particularly in natural hosts, are scarce. Here, we compared miRNA profiles of the glandular stomach of C. muris-infected and uninfected BALB/c mice using microarray sequencing. A total of 10 miRNAs (including 3 upregulated and 7 downregulated miRNAs) with significant differential expression (|FC| ≥ 2 and P value < 0.05) were identified in the glandular stomach of BALB/c mice 8 h after infection with C. muris. MiRWalk and miRDB online bioinformatics tools were used to predict the target genes of differentially expressed miRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to annotate the target genes. GO analysis indicate that gene transcription-related and ion transport-related GO terms were significantly enriched. In addition, the KEGG analyses showed that the target genes were strongly related to diverse types of tumor disease progression and anti-pathogen immunity pathways. In the current study, we firstly report changes in miRNA expression profiles in the glandular stomach of BALB/c mice at the early phase of C. muris invasion. This dysregulation in miRNA expression may contribute to our understanding of cryptosporidiosis pathology. This study provides a new perspective on the miRNA regulatory mechanisms of cryptosporidiosis, which may help in the development of effective control strategies against this pathogen.

Trypanosoma lewisi in blood of Rattus rattus complex residing in human settlements, Nakhon Si Thammarat, Thailand: Microscopic and molecular investigations

Trypanosomes are blood parasites infected in various mammals, including rats. The presence of rats in human settlements can increase the chance of Trypanosoma transmission to humans. The molecular study of multispacer in Trypanosoma spp. in naturally infected rodents in Thailand is scanty. The objective of this study was to detect Trypanosoma in the blood of the captured rats in Nakhon Si Thammarat, Thailand, using microscopic and molecular techniques. This was a cross-sectional study conducted in human settlement areas. Ninety-nine blood samples were collected using cardiac puncture. A blood sample was smeared on a glass slide and examined using a compound light microscope and a scanning electron microscope. Moreover, polymerase chain reaction was applied to detect Trypanosoma evansi and T. lewisi in the blood. An additional primer set was used to confirm the species of the detected trypanosome. Approximately 18% of the rats had positive Trypanosoma infections. All Trypanosoma-positive blood samples were matched with sequences of T. lewisi. The stumpy form of trypanosome had higher nucleus related parameters than the slender form. Interestingly, the partial sequences of the alpha-tubulin gene of T. lewisi were first reported in the naturally infected RrC in this study. Based on the results obtained, T. lewisi biology, particularly the virulent components and route of transmission, pathogenesis, and in vitro experiments, are strongly recommended for further study.

Molecular epidemiology of Cryptosporidium species in Kpong and its environs, Ghana

BACKGROUND

Cryptosporidium is a ubiquitous enteric protozoan pathogen infecting humans, domestic animals, and wildlife worldwide. It is a waterborne pathogen with recognized zoonotic potential and a definite cause of diarrhea and nutritional disorders in institutional and community settings. One challenge facing the world's supply of clean drinking water is contamination from feces and soil. It has been established that small quantities of oocysts, the infective stage, can cause human disease. Also, their resistance to chlorination and other water treatment procedures has been demonstrated. Kpong, a community in the Lower Manya Krobo Municipality of the Eastern Region of Ghana, is one of the primary sources of water supply to Accra, the capital city of Ghana. Being able to determine the effectiveness of water treatment processes and identifying sources of contamination of this pathogen in our water bodies is thus of public health importance. The study aimed to conduct molecular epidemiology of Cryptosporidium spp. in the Lower Manya Krobo Municipality.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 230 samples, 180 fecal samples from cattle and 50 water samples (tap water and well water) were collected from the following communities: Kpong, Akwernor, Ablotsi, Nuaso, and Atua, all in the Lower Manya Krobo Municipality. Samples were screened for Cryptosporidium by microscopy and PCR. The 18S rRNA gene was amplified by nested polymerase chain reaction (PCR), and the final product was sequenced. The prevalence of Cryptosporidium from the fecal samples was estimated as 10% (18/180) by microscopy, while all 50 water samples were negative. However, PCR gave the prevalence of Cryptosporidium as 47.8% (86/180) for fecal samples and 20% (10/50) for water samples. Based on the 18S rRNA gene, three sequenced samples showed high homology to C. parvum species. The phylogenetic analysis confirmed this as these sequences clustered with C. parvum sequences from other countries.

CONCLUSION/SIGNIFICANCE

Cryptosporidium parvum was identified as the persistent species in the study communities. This outcome supports the evidence that domesticated animals serve as potential reservoirs of zoonotic transmission of cryptosporidiosis. The persistence of cryptosporidiosis in cattle indicates its presence in the human population. In addition, the presence of Cryptosporidium parvum in the wells makes it alarming and necessary to consider a holistic approach such as One Health Strategies to identify and control cases in humans.

Ecology and epidemiology of Salmonella spp. isolated from the environment and the roles played by wild animals in their maintenance

Salmonella is a ubiquitous organism of public health importance that causes diarrhea and other systemic disease syndromes. The ecology and epidemiology of the organism in addition to the roles played by wild animals are important in understanding its disease. Relevant published peer-reviewed literature was obtained after imputing the study's keywords into the Google search engine. The publications were thereafter saved for the study. The study revealed the ecology of Salmonella is directly related to its epidemiology. These were found to be either positively or negatively influenced by the living and non-living parts of the environment. Free-ranging and captive wild animals can serve as asymptomatic carriers of Salmonella, therefore, help to maintain the cycle of the disease since wildlife serves as reservoir hosts to over 70% of emerging zoonotic diseases. Cockroaches transmit Salmonella through their feces, and body parts and when ingested by birds and animals. The statistically significant over 83% of Salmonella isolation in lizards suggests the reptile could be a source of Salmonella distribution. Snakes, foxes, badgers, rodents, and raccoons have been reported to have Salmonella as a natural component of their gut with the ability to shed the organism often. The high occurrence (>45%) of diverse Salmonella serovars coupled with the fact that some of these animals were handled, kept as pets and consumed by man portends these animals as potential sources of transmission of the organism and the disease. The etiology and epidemiology of Salmonella are overtly affected by several environmental factors which also determine their survival and maintenance. The roles played by wild animals in the relationship, transmission, growth or interaction within and between Salmonella spp., the occurrence, prevalence, and distribution of the organism help maintain the organism in the environment. An understanding of the roles played by the different parts of the environment and wild animals in the ecology and epidemiology of Salmonella can help make informed decisions on the prevention and control of the diseases it causes. This review aimed to investigate the relationship between ecology, epidemiology, and environment, including the roles played by wild animals in the maintenance of the organism and its disease.

Occurrence and characteristics of extended-spectrum-β-lactamase producing Escherichia coli (blaTEM-128) isolated from Mus musculus captured from a veterinary clinic and houses in Tunis, Tunisia

Antimicrobial resistance in Enterobacteriaceae is a public health problem. Rodents, can be a potential vector for transmission of multidrug resistant bacteria between animals, humans, and environment. The aim of our study was to assess the level of Enterobacteriaceae present in the intestines of rats collected from different locations in Tunisia, then to determine their antimicrobial susceptibility profiles, to screen extended spectrum β-lactamases-producing strains and determine the molecular mechanism of β-lactams resistance. Between July 2017 and June 2018, 55 strains of Enterobacteriaceae were isolated from 71 rats captured in various locations in Tunisia. Antibiotic susceptibility testing was performed using the disc diffusion method. Genes encoding ESBL and mcr genes were investigated by RT-PCR, standard PCR and sequencing when these genes were found. Fifty-five strains of Enterobacteriaceae were identified. The overall prevalence of ESBL production found in our study was 12.7 % (7/55) of which two E. coli strains were DDST positive, one isolated from a house-caught rat and one from the veterinary clinic and harbored the bla_TEM-128 gene. In addition, the other five strains were DDST negative and harbored the bla_TEM gene, including three strains isolated from collective restaurant (n = 2: bla_TEM-163; n = 1: bla_TEM-1), one strain isolated from the veterinary clinic (bla_TEM-82), and one strain isolated from a house (bla_TEM-128). The results of our study suggest that rodents may play a role in the spread of antimicrobial resistant E. coli, highlighting the need to protect the environment and monitor antimicrobial resistant bacteria in rodents to prevent their spread to other wildlife and humans.

Detection and Molecular Characterization of Giardia and Cryptosporidium spp. Circulating in Wild Small Mammals from Portugal

Cryptosporidium spp. and Giardia spp. are important diarrhea-causing protozoan parasites worldwide that exhibit broad host ranges. Wild small mammals can harbor host-adapted and potentially zoonotic species of both parasites. The aim of this study was to investigate Cryptosporidium spp. and Giardia spp. in wild rodents and shrews in Portugal, focusing on the protist's occurrence and genetic diversity. Molecular screening by PCR at the small subunit (SSU) rRNA gene locus of 290 fecal samples from wood mice (Apodemus sylvaticus), southwestern water voles (Arvicola sapidus), Cabrera's voles (Microtus cabrerae), Lusitanian pine voles (Microtus lusitanicus), Algerian mice (Mus spretus) and greater white-toothed shrews (Crocidura russula) in Northeast Portugal revealed the low occurrence of Cryptosporidium spp. (1%) and high occurrence of Giardia spp. (32.8%). The analysis revealed that "species" was the only significant factor associated with the increasing probability of Giardia spp. infection, with the highest prevalence reported in southwestern water voles and Lusitanian pine voles. Cryptosporidium and Giardia species determination at the SSU rRNA gene locus revealed C. muris and G. microti as the only circulating species, respectively. Subtyping of the glutamate dehydrogenase (gdh) and beta-giardin (bg) genes provided evidence of the high genetic diversity within the G. microti clade. This study suggests that rodent-adapted G. microti occurs to a large extent in cricetid hosts and supports the limited role of wild rodents and shrews as natural sources of human infections in Northeast Portugal regarding the investigated parasites. Moreover, this is the first record of G. microti in southwestern water voles, Lusitanian pine voles, Algerian mice, wood mice and Cabrera's voles and C. muris in Cabrera's voles. Finally, this study improves the database of sequences relevant for the sequence typing of G. microti strains and provides new insights about the epidemiology of Giardia spp. and Cryptosporidium spp. in wild rodents and shrews, two parasite genera of high importance for public and animal health.

Novel genotypes of Cryptosporidium and Enterocytozoon bieneusi detected in plateau zokors (Myospalax baileyi) from the Tibetan Plateau

The plateau zokor (Myospalax baileyi) is a small subterranean rodent endemic to China that lives alone in sealed underground burrows at altitudes ranging from 2000 to 4200 m above sea level on the Tibetan Plateau. Due to the unique environmental factors in the Tibetan Plateau, intestinal parasites in the local population may be more likely to develop host-adapted genotypes. We therefore conducted an epidemiological survey of common intestinal parasites in plateau zokors on the Tibetan plateau to estimate their actual gastrointestinal parasite status. Two areas with high populations of plateau zokor in Xunhua County, Qinghai Province were selected as sampling sites, and a total of 98 zokors were trapped. Four parasites, Cryptosporidium spp., Enterocytozoon bieneusi, Giardia lamblia and Blastocystis hominis, were tested in the faecal samples. The results showed that a new genotype of Cryptosporidium sp. was identified by amplification and sequencing of a portion of the small subunit ribosomal RNA (SSU rRNA) gene with an infection rate of 1.0% (1/98), and new genotypes of E. bieneusi were identified by amplification and sequencing of a portion of the internal transcribed spacer (ITS) region of the ribosomal RNA gene sequences with an infection rate of 4.1% (4/98). Neither of the two intestinal parasites, G. lamblia and B. hominis, was detected.

Molecular characterization of Cryptosporidium spp., Enterocytozoon bieneusi and Giardia duodenalis in laboratory rodents in China

Cryptosporidium spp., Enterocytozoon bieneusi and Giardia duodenalis are significant zoonotic intestinal pathogens that can cause gastrointestinal symptoms such as diarrhea and induce a host immune response. A total of 1237 fecal samples were collected from laboratory rodents (rats, mice and guinea pigs) from four different locations in China to investigate the infection rates and molecular characterization of these pathogens on experimental animals. Genomic DNA was extracted from each sample, and PCR amplifications were done. Overall, the Cryptosporidium spp. infection rate was 3.8% (47/1237). Four known Cryptosporidium species were identified, namely C. parvum, C. muris, C. tyzzeri and C. homai, the three former being zoonotic species. The overall E. bieneusi infection rate was 3.0% (37/1237). Seven known E. bieneusi genotypes, namely S7, BEB6, J, Henan-IV, CHG10, D and WL6, were detected by sequence analysis. Among these, genotypes D, Henan-IV and CHG10 have a high zoonotic risk. Giardia duodenalis was not detected at any of the three loci (SSU rRNA, bg and gdh) after PCR amplification. This study provides basic data for these pathogens in laboratory rodents in China and lays the foundation for their prevention and control in laboratory animals.