Multiple Cryptosporidium genotypes detected in wild black rats (Rattus rattus) from northern Australia

Critters and contamination: Zoonotic protozoans in urban rodents and water quality

Rodents represent the single largest group within mammals and host a diverse array of zoonotic pathogens. Urbanisation impacts wild mammals, including rodents, leading to habitat loss but also providing new resources. Urban-adapted (synanthropic) rodents, such as the brown rat (R. norvegicus), black rat (R. rattus), and house mouse (Mus musculus), have long successfully adapted to living close to humans and are known carriers of zoonotic pathogens. Two important enteric, zoonotic protozoan parasites, carried by rodents, include Cryptosporidium and Giardia. Their environmental stages (oocysts/cysts), released in faeces, can contaminate surface and wastewaters, are resistant to common drinking water disinfectants and can cause water-borne related gastritis outbreaks. At least 48 species of Cryptosporidium have been described, with C. hominis and C. parvum responsible for the majority of human infections, while Giardia duodenalis assemblages A and B are the main human-infectious assemblages. Molecular characterisation is crucial to assess the public health risk linked to rodent-related water contamination due to morphological overlap between species. This review explores the global molecular diversity of these parasites in rodents, with a focus on evaluating the zoonotic risk from contamination of water and wasterwater with Cryptosporidium and Giardia oocysts/cysts from synanthropic rodents. Analysis indicates that while zoonotic Cryptosporidium and Giardia are prevalent in farmed and pet rodents, host-specific Cryptosporidium and Giardia species dominate in urban adapted rodents, and therefore the risks posed by these rodents in the transmission of zoonotic Cryptosporidium and Giardia are relatively low. Many knowledge gaps remain however, and therefore understanding the intricate dynamics of these parasites in rodent populations is essential for managing their impact on human health and water quality. This knowledge can inform strategies to reduce disease transmission and ensure safe drinking water in urban and peri‑urban areas.

Biochemical and genotyping analyses of camels (Camelus dromedaries) trypanosomiasis in North Africa

Camels are considered an important food source in North Africa. Trypanosomiasis in camels is a life-threatening disease that causes severe economic losses in milk and meat production. Therefore, the objective of this study was to determine the trypanosome genotypes in the North African region. Trypanosome infection rates were determined by microscopic examination of blood smears and polymerase chain reaction (PCR). In addition, total antioxidant capacity (TAC), lipid peroxides (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were determined in erythrocyte lysate. Furthermore, 18S amplicon sequencing was used to barcode and characterizes the genetic diversity of trypanosome genotypes in camel blood. In addition to Trypanosoma, Babesia and Thelieria were also detected in the blood samples. PCR showed that the trypanosome infection rate was higher in Algerian samples (25.7%) than in Egyptian samples (7.2%). Parameters such as MDA, GSH, SOD and CAT had significantly increased in camels infected with trypanosomes compared to uninfected control animals, while TAC level was not significantly changed. The results of relative amplicon abundance showed that the range of trypanosome infection was higher in Egypt than in Algeria. Moreover, phylogenetic analysis showed that the Trypanosoma sequences of Egyptian and Algerian camels are related to Trypanosoma evansi. Unexpectedly, diversity within T. evansi was higher in Egyptian camels than in Algerian camels. We present here the first molecular report providing a picture of trypanosomiasis in camels, covering wide geographical areas in Egypt and Algeria.

Kinetoplastid Species Maintained by a Small Mammal Community in the Pantanal Biome

Kinetoplastids include species economically important in agriculture, livestock, and human health. We evaluated the richness of kinetoplastids that infect small mammals in patches of unflooded forests in the Pantanal biome, an area where we hypothesize that its diversity is higher than currently recognized. Hemocultures (HC) and Next Generation Sequencing (NGS) targeting the 18S rDNA gene were employed for the detection of kinetoplastids. We grouped the positive samples into pools for each small mammal species (Monodelphis domestica, Thylamys macrurus, Oecomys mamorae, Thrichomys fosteri, Clyomys laticeps, and Holochilus chacarius). Eight parasite species were identified: Leishmania amazonensis, L. infantum; Trypanosoma cascavelli (HC + NGS), T. cruzi, T. lainsoni, T. rangeli (HC + NGS), Trypanosoma sp. DID, and Neobodo sp. The use of a tool as sensitive as NGS has increased our awareness of the diversity of kinetoplastids, as well as their host range, with emphasis on the species O. mamorae (seven kinetoplastid species, excepting T. cascavelli in a pool of nine individuals) and T. macrurus (four kinetoplastid species in a single individual). Furthermore, L. infantum and L. amazonensis infections were described in small mammals from this region for the first time. These findings make it mandatory to revisit the kinetoplastids/host associations proposed so far.

Public health and ecological significance of rodents in Cryptosporidium infections

Cryptosporidium is one of the most important genera of intestinal zoonotic pathogens that cause diarrhea in both humans and animals. Rodents are common and important hosts or carriers of pathogens with public health importance, and rodents play an important role in the ecology of zoonotic transmission. The overall worldwide prevalence of Cryptosporidium spp. in rodents is 19.8% (4589/23142). Twenty-five known Cryptosporidium species and 43 genotypes have been identified, and C. parvum is the dominant species in rodents worldwide. Rodents transfer pathogens to humans by the direct route or by serving as intermediate hosts transmitting the pathogens to other animals. We review the epidemiology, diversity, and transmission routes of Cryptosporidium spp. in rodents. The main purpose of this review is to highlight Cryptosporidium infection in rodents and its transmission, associated risk factors, and prevention; in addition, we assess the public health and ecological significance of Cryptosporidium infections from the One Health perspective.

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Review of the epidemiology and diversity of Cryptosporidium in rodents.

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The overall worldwide prevalence is 19.8% (4589/23142), C. parvum is the dominant species.

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Public health and ecological significance of rodent-borne Cryptosporidium at “One Health” perspective.

Molecular Detection of Cryptosporidium spp. and Enterocytozoon bieneusi Infection in Wild Rodents From Six Provinces in China

Enterocytozoon (E.) bieneusi and Cryptosporidium spp. are the most important zoonotic enteric pathogens associated with diarrheal diseases in animals and humans. However, it is still not known whether E. bieneusi and Cryptosporidium spp. are carried by wild rodents in Shanxi, Guangxi, Zhejiang, Shandong, and Inner Mongolia, China. In the present study, a total of 536 feces samples were collected from Rattus (R.) norvegicus, Mus musculus, Spermophilus (S.) dauricus, and Lasiopodomys brandti in six provinces of China, and were detected by PCR amplification of the SSU rRNA gene of Cryptosporidium spp. and ITS gene of E. bieneusi from June 2017 to November 2020. Among 536 wild rodents, 62 (11.6%) and 18 (3.4%) samples were detected as E. bieneusi- and Cryptosporidium spp.-positive, respectively. Differential prevalence rates of E. bieneusi and Cryptosporidium spp. were found in different regions. E. bieneusi was more prevalent in R. norvegicus, whereas Cryptosporidium spp. was more frequently identified in S. dauricus. Sequence analysis indicated that three known Cryptosporidium species/genotypes (Cryptosporidium viatorum, Cryptosporidium felis, and Cryptosporidium sp. rat genotype II/III) and two uncertain Cryptosporidium species (Cryptosporidium sp. novel1 and Cryptosporidium sp. novel2) were present in the investigated wild rodents. Meanwhile, 5 known E. bieneusi genotypes (XJP-II, EbpC, EbpA, D, and NCF7) and 11 novel E. bieneusi genotypes (ZJR1 to ZJR7, GXM1, HLJC1, HLJC2, and SDR1) were also observed. This is the first report for existence of E. bieneusi and Cryptosporidium spp. in wild rodents in Shanxi, Guangxi, Zhejiang, and Shandong, China. The present study also demonstrated the existence of E. bieneusi and Cryptosporidium spp. in S. dauricus worldwide for the first time. This study not only provided the basic data for the distribution of E. bieneusi and Cryptosporidium genotypes/species, but also expanded the host range of the two parasites. Moreover, the zoonotic E. bieneusi and Cryptosporidium species/genotypes were identified in the present study, suggesting wild rodents are a potential source of human infections.

Cryptosporidium spp. in wild murids (Rodentia) from Corsica, France

Cryptosporidium spp. are worldwide protozoan parasites that can affect to a broad range of vertebrate hosts, including rodents. In the island of Corsica (France), there are no previous data about these protozoa infecting wild rodents. To estimate the distribution and occurrence, a total of 117 wild murine rodents of the species Rattus rattus (84), Mus musculus domesticus (21), Apodemus sylvaticus (11), and Rattus norvegicus (1) were captured in 24 different biotopes. Fecal samples were screened for Cryptosporidium spp. by nested PCR to amplify an 830 bp fragment of the 18S rRNA gene. As general occurrence, 15.4% of the rodents analyzed were positive for Cryptosporidium spp., being detected widely distributed along the island in R. rattus (17.6%) and M. m. domesticus (14.3%). Cryptosporidium viatorum, Cryptosporidium sp. rat genotype II, and Cryptosporidium sp. rat genotype III were successfully identified in R. rattus. The results herein reported provide the first data on Cryptosporidium spp. in wild murine species from a Mediterranean island and constitute the first report of the zoonotic species C. viatorum in R. rattus. Although a low occurrence of Cryptosporidium spp. in murids was obtained and only in one animal the zoonotic species C. viatorum was identified, our results highlight that wild murine rodents from Corsica could mediate in the maintenance and transmission of this protozoan to the environment and other hosts including humans and animals. Further studies are required to better understand the epidemiology of Cryptosporidium spp. in wild rodents from Corsica and their possible public health repercussions.

Zoonotic Cryptosporidium spp. in Wild Rodents and Shrews

There has been a significant increase in the number of reported human cryptosporidiosis cases in recent years. The aim of this study is to estimate the prevalence of Cryptosporidium spp. in wild rodents and shrews, and investigate the species and genotype distribution to assess zoonotic risk. Partial 18S rRNA gene nested-PCR reveals that 36.8, 53.9 and 41.9% of mice, voles and shrews are infected with Cryptosporidium species. The highest prevalence occurred in the Microtus agrestis (field vole) and Myodes glareolus (bank vole). Interestingly, bank voles caught in fields were significantly more often Cryptosporidium-positive compared to those caught in forests. The proportion of infected animals increases from over-wintered (spring and summer) to juveniles (autumn) suggesting acquired immunity in older animals. Based on Sanger sequencing and phylogenetic analyses, Apodemus flavicollis (yellow-necked mouse) is commonly infected with zoonotic C. ditrichi. Voles carry multiple different Cryptosporidium sp. and genotypes, some of which are novel. C. andersoni, another zoonotic species, is identified in the Craseomys rufocanus (grey-sided vole). Shrews carry novel shrew genotypes. In conclusion, this study indicates that Cryptosporidium protozoan are present in mouse, vole and shrew populations around Finland and the highest zoonotic risk is associated with C. ditrichi in Apodemus flavicollis and C. andersoni in Craseomys rufocanus. C. parvum, the most common zoonotic species in human infections, was not detected.

Cryptosporidium ratti n. sp. (Apicomplexa: Cryptosporidiidae) and genetic diversity of Cryptosporidium spp. in brown rats (Rattus norvegicus) in the Czech Republic

The diversity and biology of Cryptosporidium that is specific for rats (Rattus spp.) are not well studied. We examined the occurrence and genetic diversity of Cryptosporidium spp. in wild brown rats (Rattus norvegicus) by microscopy and polymerase chain reaction (PCR)/sequencing targeting the small subunit rDNA (SSU), actin and HSP70 genes. Out of 343 faecal samples tested, none were positive by microscopy and 55 were positive by PCR. Sequence analysis of SSU gene revealed the presence of Cryptosporidium muris (n = 4), C. andersoni (n = 3), C. ryanae (n = 1), C. occultus (n = 3), Cryptosporidium rat genotype I (n = 23), Cryptosporidium rat genotype IV (n = 16) and novel Cryptosporidium rat genotype V (n = 5). Spherical oocysts of Cryptosporidium rat genotype I obtained from naturally-infected rats, measuring 4.4-5.4 μm × 4.3-5.1 μm, were infectious to the laboratory rats, but not to the BALB/c mice (Mus musculus) nor Mongolian gerbils (Meriones unguiculatus). The prepatent period was 3 days post infection and the patent period was longer than 30 days. Naturally- and experimentally-infected rats showed no clinical signs of disease. Percentage of nucleotide similarities at the SSU, actin, HSP70 loci between C. ratti n. sp. and the rat derived C. occultus and Cryptosporidium rat genotype II, III, IV, and V ranged from 91.0 to 98.1%. These genetic variations were similar or greater than that observed between closely related species, i.e. C. parvum and C. erinacei (93.2-99.5%). Our morphological, genetic and biological data support the establishment of Cryptosporidium rat genotype I as a new species, Cryptosporidium ratti n. sp.

Cryptosporidium animal species in Iran: a systematic review and meta-analysis

BACKGROUND

Cryptosporidiosis is an acute and short-term infection which can lead to severe diarrhea (intestinal cryptosporidiosis) associated with a persistent cough in the host with immune system defect. This systematic review and meta-analysis was conducted to estimate the prevalence of animal Cryptosporidium species and the corresponding epidemiological aspects in Iran.

METHODS

In this study, all original research articles relating to the animal cryptosporidiosis in Iran were collected from reliable databases using keywords. A meta-analysis was conducted separately for each subgroup, and heterogeneity among the studies was performed using the Q and I2 tests. Furthermore, it should be noticed that the significance level in the statistical analysis with the Comprehensive Meta-analysis software was considered to be less than 0.05. Finally, meta-analysis results were shown in forest plot with a 95% CI.

RESULTS

In total, 4795 studies were included in the initial screening. Duplicated or non-original studies and the ones which did not meet our considered criteria were excluded from the list. Out of the 100 articles included in our first list for the meta-analysis, 40, 16, 13, 10, 9, 7, and 5 were done on cattle and calves, birds, dogs, sheep, rodents, camels, and horses, respectively. The prevalence rate of cryptosporidiosis among the birds, horses, rodents, camels, dogs, cattle, and sheep in Iran was estimated to be 7.5%, 19.5%, 20.8%, 8.4%, 4.9%, 14.4%, and 9.1%, respectively.

CONCLUSION

The different Cryptosporidium species have been found in different regions of Iran. Geographical region, climate, and domestic animals are considered as factors responsible for animal cryptosporidiosis prevalence in the area. Moreover, this parasite is zoonotic which causes disease in animals as well as humans which can result in economic loss.

Diversity of Cryptosporidium spp. in wild rodents from the Canary Islands, Spain

BACKGROUND

Cryptosporidium spp. are worldwide protozoan parasites which include species that can lead to cryptosporidiosis in humans. Different animal species can serve as reservoirs and sources of dissemination of the disease, such as rodent species due their potential in transmitting zoonotic pathogens to humans and other animals. In the Canary Islands (Spain), Cryptosporidium parvum and Cryptosporidium hominis have been identified in patients with diarrhea. However, the occurrence of Cryptosporidium spp. in possible reservoirs in this archipelago remains unclear. Considering the zoonotic potential of these protozoans, the aim of the present study was to determine the presence of Cryptosporidium spp. in peridomestic wild rodents and the possible role of these mammals as a source of transmission of these protozoans in Canary Islands.

METHODS

A total of 179 rodents belonging to Rattus rattus and Mus musculus domesticus from four Canary Islands, La Palma, El Hierro, Tenerife and Lanzarote, were analyzed. Feces were screened for Cryptosporidium spp. by nested PCR of the 18S ribosomal RNA fragment and the sequences used for phylogenetic analyses.

RESULTS

Cryptosporidium spp. were found widely distributed with an overall prevalence of 12.30% in rodents (13.86% for R. rattus and 10.25% for M. m. domesticus). The overall prevalence by island was 19.60% for Tenerife, 7.14% for La Palma, 5.71% for El Hierro and 0% for Lanzarote. Cryptosporidium tyzzeri, Cryptosporidium meleagridis, Cryptosporidium muris and Cryptosporidium sp. rat genotype I and II/III were successfully identified, in addition to two unidentified Cryptosporidium genotypes.

CONCLUSIONS

This study contributes to the knowledge of the biodiversity and distribution of Cryptosporidium spp. in wild rodents from the Canary Islands, highlighting the presence of three zoonotic species, C. tyzzeri, C. meleagridis and C. muris, being the first detection of these three species in wild rodents in the Canary Islands and the first report of C. meleagridis in R. rattus. Given the results obtained in our study, future studies in non-sampled areas are required to better understand the epidemiology of these protozoans in wild rodents in the archipelago.

Serosurvey and molecular detection of the main zoonotic parasites carried by commensal Rattus norvegicus population in Tehran, Iran

Background

Rattus norvegicus are reservoirs for transmission of various zoonotic parasites, and they have become a threat to public health worldwide. Given the large number and the significant presence of R. norvegicus throughout the city of Tehran, this study aims to assess the frequency of zoonotic parasites carried by commensal rodents wandering in Tehran, Iran. The study considered the north, south, west, east, and center regions of Tehran for the purposes of this study. The serological tests were applied in order to detect effective antibodies against Trichomonas vaginalis (T. vaginalis), Babesia spp., and Cryptosporidium spp. using a commercial qualitative rat ELISA kit. The frequency of Toxoplasma gondii (T. gondii) was surveyed by using the conventional PCR method. Furthermore, nested PCR was employed to detect the presence of Giardia spp. and Leishmania spp. in commensal R. norvegicus dispersed in Tehran.

Results

Approximately, 76% of the 100 R. norvegicus tested were infected with at least one zoonotic parasite, indicating the significant frequency of parasites within the study areas. Seroreactivity against T. vaginalis, Babesia spp., and Cryptosporidium spp. was detected in 5%, 0%, and 1% of the R. norvegicus tested, respectively. T. gondii DNA was detected in 32 out of 100 (32%) R. norvegicus. In addition, Leishmania spp. and Giardia spp. DNA were found in 18 out of 100 (18%) and 76 out of 100 (76%) R. norvegicus investigated, respectively. T. vaginalis with 15% and T. gondii with 70% had the highest frequency of parasites among the R. norvegicus collected from the western and northeastern regions of Tehran, respectively. Moreover, Giardia spp. with 95% and Leishmania spp. with 30% had the highest frequency in the east and center districts, respectively.

Conclusion

The findings showed a wide geographical dissemination of Giardia spp., Toxoplasma gondii, and Leishmania spp. in R. norvegicus within five districts of Tehran. In contrast, other parasites such as Cryptosporidium spp. infection were rarely detected in Rattus populations. No evidence for the circulation of Babesia spp. was found in this study.

Effect of urban habitat use on parasitism in mammals: a meta-analysis

Rates of urbanization are increasing globally, with consequences for the dynamics of parasites and their wildlife hosts. A small subset of mammal species have the dietary and behavioural flexibility to survive in urban settings. The changes that characterize urban ecology—including landscape transformation, modified diets and shifts in community composition—can either increase or decrease susceptibility and exposure to parasites. We used a meta-analytic approach to systematically assess differences in endoparasitism between mammals in urban and non-urban habitats. Parasite prevalence estimates in matched urban and non-urban mammal populations from 33 species were compiled from 46 published studies, and an overall effect of urban habitation on parasitism was derived after controlling for study and parasite genus. Parasite life cycle type and host order were investigated as moderators of the effect sizes. We found that parasites with complex life cycles were less prevalent in urban carnivore and primate populations than in non-urban populations. However, we found no difference in urban and non-urban prevalence for parasites in rodent and marsupial hosts, or differences in prevalence for parasites with simple life cycles in any host taxa. Our findings therefore suggest the disruption of some parasite transmission cycles in the urban ecological community.

Cryptosporidium spp. in wild rats (Rattus spp.) from the Hainan Province, China: Molecular detection, species/genotype identification and implications for public health

Wild rats (Rattus spp.) carry many zoonotic pathogens including Cryptosporidium. Due to the close proximity of rats to humans in urban environments, the potential for disease transmission is high. Cryptosporidium is a protozoan parasite which when ingested causes serious human illness. Despite its importance, genetic characterization of Cryptosporidium in wild rats in the Hainan province of China has not been performed. In this study, we analyzed the occurrence and genetics of Cryptosporidium in wild rats from Hainan, China. From December 2017 to October 2018, 150 wild rats were captured and fresh fecal material was collected from intestinal sections. Rat species were identified by PCR-based amplification and analysis of the vertebrate cytochrome b (cytb) gene. Cryptosporidium was examined by PCR amplification of the partial small subunit of ribosomal DNA (SSU rDNA). C. viatorum were subtyped by PCR analysis of the gp60 gene. A total of four rat species were identified including Asian house rats (Rattus tanezumi) (n = 46), brown rats (Rattus norvegicus) (n = 56), Edward's long-tailed rats (Leopoldamys edwardsi) (n = 38) and muridae (Niviventer fulvescens) (n = 10), with Cryptosporidium positive rates of 73.9%, 28.6%, 55.3% and 40.0%, respectively (average infection rate: 50.0%, 75/150. Sequence analysis confirmed the presence of four Cryptosporidium species and two genotypes including C. viatorum (n = 11); C. occultus (n = 2); C. muris (n = 1); and C. erinacei (n = 1); rat genotypes III (n = 13) and IV (n = 47). Three novel subtypes of C. viatorum were identified in 6 of the 11 infected Edward's long-tailed rats: XVcA2G1a (n = 4), XVcA2G1b (n = 1) and XVdA3 (n = 1). The identification of human pathogenic C. viatorum and zoonotic C. occultus, C. muris and C. erinacei, suggested that wild rats infected with Cryptosporidium pose a threat to human health. Taken together, these findings highlight the need to control the rat population in Hainan, China. The need to improve the public awareness of the risk of disease transmission from wild rats to humans is also highlighted.

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This is the first report of the identification of Cryptosporidium in wild rats in Hainan Province, China.

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A total of 75 out of 150 (50.0%) specimens were PCR-positive for Cryptosporidium.

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Six known species or genotypes and three novel subtypes of C. viatorum were identified.

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The possibility of transmission of Cryptosporidium between wild rats and humans was suggested.

Molecular characterizations of Cryptosporidium spp. and Enterocytozoon bieneusi in brown rats (Rattus norvegicus) from Heilongjiang Province, China

Background

Cryptosporidium spp. and Enterocytozoon bieneusi are prevalent zoonotic pathogens responsible for the high burden of diarrheal diseases worldwide. Rodents are globally overpopulated and are known as reservoirs or carriers of a variety of zoonotic pathogens including Cryptosporidium spp. and E. bieneusi. However, few data are available on genetic characterizations of both pathogens in rodents in China. The aim of the present work was to determine the prevalence and genetic characterizations of Cryptosporidium spp. and E. bieneusi in brown rats (Rattus norvegicus) from Heilongjiang, China.

Methods

A total of 242 wild brown rats were captured in Heilongjiang Province of China. A fresh fecal specimen was collected directly from the intestinal and rectal content of each brown rat. All the fecal specimens were examined for the presence of Cryptosporidium spp. and E. bieneusi by PCR and sequencing of the partial small subunit (SSU) rRNA gene and the internal transcribed spacer (ITS) region of the rRNA gene of the two pathogens, respectively.

Results

The infection rate was 9.1% (22/242) for Cryptosporidium spp. and 7.9% (19/242) for E. bieneusi. Sequence analysis confirmed the presence of C. ubiquitum (1/22, 4.5%) and three genotypes of Cryptosporidium, including Cryptosporidium rat genotype I (14/22, 63.6%), Cryptosporidium rat genotype IV (6/22, 27.3%) and Cryptosporidium suis-like genotype (1/22, 4.5%). Meanwhile, two E. bieneusi genotypes were identified, including D (17/19, 89.5%) and Peru6 (2/19, 10.5%).

Conclusions

To the best of our knowledge, Enterocytozoon bieneusi genotype Peru6 was identified in rodents for the first time globally and Cryptosporidium rat genotype I and Cryptosporidium rat genotype IV were found in rats in China for the first time. The finding of zoonotic C. ubiquitum and C. suis-like genotype, as well as E. bieneusi genotypes, suggests that brown rats pose a threat to human health. It is necessary to control brown rat population in the investigated areas and improve local people’s awareness of the transmission risk of the two pathogens from brown rats to humans.

Cryptosporidium infecting wild cricetid rodents from the subfamilies Arvicolinae and Neotominae

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.

Rodents as a reservoir of infection caused by multiple zoonotic species/genotypes of C. parvum, C. hominis, C. suis, C. scrofarum, and the first evidence of C. muskrat genotypes I and II of rodents in Europe

Cryptosporidium spp. is an important causative agent of intestinal parasitoses-induced diarrhoea in humans and animals worldwide. Rodents (small mammals), the main reservoir of infections, are globally expanded and overpopulated, which increases the risk of transfer of human and zoonotic pathogens from the genus Cryptosporidium. In this study, Cryptosporidium was detected in wild immunocompetent asymptomatic small mammals. Altogether 262 fecal samples were collected from five areas in Eastern Slovakia from four different rodent species (Myodes glareolus, Apodemus agrarius, Apodemus flavicollis, Rattus norvegicus), eight samples originated from two insectivore species (Sorex araneus, Crocidura suaveolens), and two sample from a carnivore Mustela nivalis. The samples were examined using a method modified in our laboratory, based on the use of specific primers on a small subunit rRNA (18S rRNA) gene for species identification, and amplification of GP60 gene coding 60-kDa glycoprotein for genotype determination. The following species were identified: Cryptosporidium parvum (n=15), genotypes IIaA18G3R1 (n=11; KU311673), IIaA10G1R1 (n=1; KU311670), IIcA5G3a (n=1; KU311669), IIiA10 (n=2; KU311672); Cryptosporidium suis (n=4; KU311671); Cryptosporidium scrofarum (n=28); Cryptosporidium environment sp. (n=12; KU311677); Cryptosporidium muskrat genotype I (n=3; KU311675); Cryptosporidium muskrat genotype II (n=3; KU311676). From one of the rodent, the species Cryptosporidium hominis genotype IbA10G2 (KU311668) was identified for the first time. The results of this study indicate low host specificity of the detected Cryptosporidium species and imply the importance of free-living small mammals in urban and suburban habitats as a potential source of human cryptosporidiosis.

Increased genetic diversity and prevalence of co-infection with Trypanosoma spp. in koalas (Phascolarctos cinereus) and their ticks identified using next-generation sequencing (NGS)

Infections with Trypanosoma spp. have been associated with poor health and decreased survival of koalas (Phascolarctos cinereus), particularly in the presence of concurrent pathogens such as Chlamydia and koala retrovirus. The present study describes the application of a next-generation sequencing (NGS)-based assay to characterise the prevalence and genetic diversity of trypanosome communities in koalas and two native species of ticks (Ixodes holocyclus and I. tasmani) removed from koala hosts. Among 168 koalas tested, 32.2% (95% CI: 25.2–39.8%) were positive for at least one Trypanosoma sp. Previously described Trypanosoma spp. from koalas were identified, including T. irwini (32.1%, 95% CI: 25.2–39.8%), T. gilletti (25%, 95% CI: 18.7–32.3%), T. copemani (27.4%, 95% CI: 20.8–34.8%) and T. vegrandis (10.1%, 95% CI: 6.0–15.7%). Trypanosoma noyesi was detected for the first time in koalas, although at a low prevalence (0.6% 95% CI: 0–3.3%), and a novel species (Trypanosoma sp. AB-2017) was identified at a prevalence of 4.8% (95% CI: 2.1–9.2%). Mixed infections with up to five species were present in 27.4% (95% CI: 21–35%) of the koalas, which was significantly higher than the prevalence of single infections 4.8% (95% CI: 2–9%). Overall, a considerably higher proportion (79.7%) of the Trypanosoma sequences isolated from koala blood samples were identified as T. irwini, suggesting this is the dominant species. Co-infections involving T. gilletti, T. irwini, T. copemani, T. vegrandis and Trypanosoma sp. AB-2017 were also detected in ticks, with T. gilletti and T. copemani being the dominant species within the invertebrate hosts. Direct Sanger sequencing of Trypanosoma 18S rRNA gene amplicons was also performed and results revealed that this method was only able to identify the genotypes with greater amount of reads (according to NGS) within koala samples, which highlights the advantages of NGS in detecting mixed infections. The present study provides new insights on the natural genetic diversity of Trypanosoma communities infecting koalas and constitutes a benchmark for future clinical and epidemiological studies required to quantify the contribution of trypanosome infections on koala survival rates.

Molecular Characterization of Cryptosporidium spp. in Wild Rodents of Southwestern Iran Using 18s rRNA Gene Nested-PCR-RFLP and Sequencing Techniques

Background. Rodents could act as reservoir for Cryptosporidium spp. specially C. parvum, a zoonotic agent responsible for human infections. Since there is no information about Cryptosporidium infection in rodents of Ahvaz city, southwest of Iran, hence, this survey was performed to determine the prevalence and molecular characterization of Cryptosporidium spp. in this region. Materials and Methods. One hundred rodents were trapped from different regions of Ahvaz city. Intestine contents and fecal specimens of rodents were studied using both microscopy examination to identify oocyst and nested-polymerase chain reaction (PCR) technique for 18s rRNA gene detection. Eventually restriction fragment length polymorphism (RFLP) method using SspI and VspI restriction enzymes was carried out to genotype the species and then obtained results were sequenced. Results. Three out of 100 samples were diagnosed as positive and overall prevalence of Cryptosporidium spp. was 3% using both modified Ziehl-Neelsen staining under light microscope and nested-PCR (830 bp) methods. Afterwards, PCR-RFLP was performed on positive samples and C. parvum pattern was identified. Finally PCR-RFLP findings were sequenced and presence of C. parvum was confirmed again. Conclusions. Our study showed rodents could be potential reservoir for C. parvum. So an integrated program for control and combat with them should be adopted and continued.

Public health significance of zoonotic Cryptosporidium species in wildlife: Critical insights into better drinking water management

Cryptosporidium is an enteric parasite that is transmitted via the faecal-oral route, water and food. Humans, wildlife and domestic livestock all potentially contribute Cryptosporidium to surface waters. Human encroachment into natural ecosystems has led to an increase in interactions between humans, domestic animals and wildlife populations. Increasing numbers of zoonotic diseases and spill over/back of zoonotic pathogens is a consequence of this anthropogenic disturbance. Drinking water catchments and water reservoir areas have been at the front line of this conflict as they can be easily contaminated by zoonotic waterborne pathogens. Therefore, the epidemiology of zoonotic species of Cryptosporidium in free-ranging and captive wildlife is of increasing importance. This review focuses on zoonotic Cryptosporidium species reported in global wildlife populations to date, and highlights their significance for public health and the water industry.

Genotyping and subtyping of Giardia and Cryptosporidium isolates from commensal rodents in China

Cryptosporidium and Giardia are two important zoonotic intestinal parasites responsible for diarrhoea in humans and other animals worldwide. Rodents, as reservoirs or carriers of Cryptosporidium and Giardia, are abundant and globally widespread. In the present study, we collected 232 fecal specimens from commensal rodents captured in animal farms and farm neighbourhoods in China. We collected 33 Asian house rats, 168 brown rats and 31 house mice. 6.0% (14/232) and 8.2% (19/232) of these rodents were microscopy-positive for Giardia cysts and Cryptosporidium oocysts, respectively. All 14 Giardia isolates were identified as Giardia duodenalis assemblage G at a minimum of one or maximum of three gene loci (tpi, gdh and bg). By small subunit rRNA (SSU rRNA) gene sequencing, Cryptosporidium parvum (n = 12) and Cryptosporidium muris (n = 7) were identified. The gp60 gene encoding the 60-kDa glycoprotein was successfully amplified and sequenced in nine C. parvum isolates, all of which belonged to the IIdA15G1 subtype. Observation of the same IIdA15G1 subtype in humans (previously) and in rodents (here) suggests that rodents infected with Cryptosporidium have the potential to transmit cryptosporidiosis to humans.

Occurrence of novel and rare subtype families of Cryptosporidium in bamboo rats (Rhizomys sinensis) in China

This report is the first to describe Cryptosporidium infection in bamboo rats (Rhizomys sinensis). Ninety-two fresh fecal specimens were collected from a pet market in Ya'an City, China. One Cryptosporidium isolate from an asymptomatic host and two isolates from separate hosts with diarrhea were obtained by using Sheather's sucrose flotation technique and modified acid-fast staining. The Cryptosporidium spp. were genotyped by nested PCR and nucleotide sequencing of the small subunit rRNA (SSU rRNA), 70-kDa heat shock protein (HSP70), oocyst wall protein (COWP), and actin genes: isolates were identified as Cryptosporidium parvum with minor nucleotide differences at all four loci. Further subtyping was performed by PCR amplification and DNA sequence analysis of the 60-kDa glycoprotein (gp60) gene: two subtype families were detected, including a novel C. parvum subtype IIpA9 and a rare subtype IIoA13G1 (only reported in diarrheal patients of Sweden). Our results suggest that the bamboo rat is a reservoir host of C. parvum. Significantly, we discovered that the rare C. parvum subtype family IIo is also a zoonotic subtype and confirmed C. parvum subtype IIpA9 as a novel subtype family.

Cryptosporidium species in sheep and goats from Papua New Guinea

Species of Cryptosporidium are extensively recognised as pathogens of domesticated livestock and poultry, companion animals, wildlife, and are a threat to public health. Little is known of the prevalence of Cryptosporidium spp. in humans, domesticated animals or wildlife in Papua New Guinea (PNG). The aim of the present study was to screen sheep and goats for Cryptosporidium using molecular tools. A total of 504 faecal samples were collected from sheep (n=276) and goats (n=228) in village, government and institutional farms in PNG. Samples were screened by nested PCR and genotyped at the 18S rRNA and at the 60kDa glycoprotein (gp60) loci. The overall prevalences were 2.2% for sheep (6/278) and 4.4% (10/228) for goats. The species/genotypes identified were Cryptosporidium hominis (subtype IdA15G1) in goats (n=6), Cryptosporidium parvum (subtypes IIaA15G2R1and IIaA19G4R1) in sheep (n=4) and in goats (n=2), Cryptosporidium andersoni (n=1) and Cryptosporidium scrofarum (n=1) in sheep, Cryptosporidium xiao (n=1) and Cryptosporidium rat genotype II (n=1) in goats. This is the first report of Cryptosporidium spp. identified in sheep and goats in PNG. Identification of Cryptosporidium in livestock warrants better care of farm animals to avoid contamination and illness in vulnerable population. The detection of zoonotic Cryptosporidium in livestock suggests these animals may serve as reservoirs for human infection.

A new set of primers directed to 18S rRNA gene for molecular identification of Cryptosporidium spp. and their performance in the detection and differentiation of oocysts shed by synanthropic rodents

Cryptosporidium spp. are cosmopolitan protozoa that infect fishes, reptiles, amphibians, birds and mammals. More than 20 species are recognized within this genus. Rodents are a group of abundant and ubiquitous organisms that have been considered reservoirs of Cryptosporidium for humans and livestock. The aim of this study was to design specific primers for the gene encoding 18S rRNA, potentially capable of amplifying any species or genotype of Cryptosporidium spp. and evaluate the diagnostic attributes of the nested-PCR based on such probes. The primers were designed to amplify the shortest segment as possible to maximize the sensitivity of the test, but preserving the discriminatory potential of the amplified sequences for phylogenetic inferences. The nested-PCR standardized in this study (nPCR-SH) was compared in terms of sensitivity with another similar assay (nPCR-XIAO) that has been largely used for the detection and identification of Cryptosporidium spp. worldwide. We also aimed to molecularly characterize samples of Cryptosporidum spp. isolated from synanthropic rodents using these probes. Forty-five rodents were captured in urban areas of the municipality of Umuarama, Paraná State, Brazil. Fecal samples were submitted to three molecular tests (nested-PCRs), two of them targeted to the 18S rDNA gene (nPCR-SH and nPCR-XIAO) and the third targeted to the gene encoding actin (nPCR-actin). The nPCR-SH was tested positive on samples of Cryptosporidum parvum, Cryptosporidum andersoni, Cryptosporidum meleagridis, Cryptosporidum hominis, Cryptosporidum canis, and Cryptosporidum serpentis. Sixteen samples of rodents were positive by nPCR-SH, six by nPCR-XIAO and five by nPCR-actin. Sequencing of amplified fragments allowed the identification of Cryptosporidum muris in three samples of Rattus rattus, and two genotypes of Cryptosporidium, the genotypes mouse II and III. Cryptosporidium genotype mouse II was found in one sample of Mus musculus and genotype mouse III, in twelve samples, being five from R. rattus and seven from M. musculus. The results of this study demonstrated that the primers designed for detection of Cryptosporidium spp. were more efficient than those used in the nPCR-XIAO. Genotypes or species of Cryptosporidium that can be usually transmitted for human beings and livestock were not found in synanthropic rodents, suggesting that the importance of these animals in zoonotic transmission of cryptosporidiosis should be revisited.

Cryptosporidium species in Australian wildlife and domestic animals

Cryptosporidium is an important enteric parasite that is transmitted via the fecal-oral route, water and food. Humans, wildlife and domestic livestock all potentially contribute Cryptosporidium to surface waters. Most species of Cryptosporidium are morphologically indistinguishable and can only be identified using molecular tools. Over 24 species have been identified and of these, 7 Cryptosporidium species/genotypes are responsible for most human cryptosporidiosis cases. In Australia, relatively few genotyping studies have been conducted. Six Cryptosporidium species (C. hominis, C. parvum, C. meleagridis, C. fayeri, C. andersoni and C. bovis) have been identified in humans in Australia. However, little is known about the contribution of animal hosts to human pathogenic strains of Cryptosporidium in drinking water catchments. In this review, we focus on the available genotyping data for native, feral and domestic animals inhabiting drinking water catchments in Australia to provide an improved understanding of the public health implications and to identify key research gaps.