Distribution and molecular characterization of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi amongst grazing adult sheep in Xinjiang, China

Unveiling the presence and genotypic diversity of Giardia duodenalis on large-scale sheep farms: insights from the Henan and Ningxia Regions, China

BACKGROUND

The parasitic protozoan Giardia duodenalis is an important cause of diarrheal disease in humans and animals that can be spread by fecal-oral transmission through water and the environment, posing a challenge to public health and animal husbandry. Little is known about its impact on large-scale sheep farms in China. In this study we investigated G. duodenalis infection of sheep and contamination of the environment in large-scale sheep farms in two regions of China, Henan and Ningxia.

METHODS

A total of 528 fecal samples, 402 environmental samples and 30 water samples were collected from seven large-scale sheep farms, and 88 fecal samples and 13 environmental samples were collected from 12 backyard farms. The presence of G. duodenalis was detected by targeting the β-giardin (bg) gene, and the assemblage and multilocus genotype of G. duodenalis were investigated by analyzing three genes: bg, glutamate dehydrogenase (gdh) and triphosphate isomerase (tpi).

RESULTS

The overall G. duodenalis detection rate was 7.8%, 1.4% and 23.3% in fecal, environmental and water samples, respectively. On the large-scale sheep farms tested, the infection rate of sheep in Henan (13.8%) was found to be significantly higher than that of sheep in Ningxia (4.2%) (P < 0.05). However, the difference between the rates of environmental pollution in Henan (1.9%) and Ningxia (1.0%) was not significant (P > 0.05). Investigations of sheep at different physiological stages revealed that late pregnancy ewes showed the lowest infection rate (1.7%) and that young lambs exhibited the highest (18.8%). Genetic analysis identified G. duodenalis belonging to two assemblages, A and E, with assemblage E being dominant. A total of 27 multilocus genotypes were identified for members of assemblage E.

CONCLUSIONS

The results suggest that G. duodenalis is prevalent on large-scale sheep farms in Henan and Ningxia, China, and that there is a risk of environmental contamination. This study is the first comprehensive examination of the presence of G. duodenalis on large-scale sheep farms in China. Challenges posed by G. duodenalis to sheep farms need to be addressed proactively to ensure public health safety.

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.

Cryptosporidium spp. in large-scale sheep farms in China: prevalence and genetic diversity

Cryptosporidium spp. are significant zoonotic intestinal parasites that induce diarrhea and even death across most vertebrates, including humans. Previous studies showed that sheep are important hosts for Cryptosporidium and that its distribution in sheep is influenced by geography, feeding patterns, age, and season. Environmental factors also influence the transmission of Cryptosporidium. Molecular studies of Cryptosporidium in sheep have been conducted in only a few regions of China, and studies into the effect of sheep-housing environments on Cryptosporidium transmission are even rarer. To detect the prevalence of Cryptosporidium in large-scale sheep-housing farms, a total of 1241 fecal samples were collected from sheep, 727 environmental samples were taken from sheep housing, and 30 water samples were collected in six regions of China. To ascertain the existence of the parasite and identify the species of Cryptosporidium spp., we conducted nested PCR amplification of DNA extracted from all samples using the small-subunit (SSU) rRNA gene as a target. For a more in-depth analysis of Cryptosporidium spp. subtypes, C. xiaoi-and C. ubiquitum-positive samples underwent separate nested PCR amplification targeting the 60 kDa glycoprotein (gp60) gene. The amplification of the Cryptosporidium spp. SSU rRNA gene locus from the whole genomic DNA of all samples yielded a positive rate of 1.2% (20/1241) in fecal samples, 0.1% (1/727) in environmental samples, and no positive samples were found in water samples. The prevalence of Cryptosporidium spp. infection in large-scale housed sheep was 1.7%, which was higher than that in free-ranging sheep (0.0%). The highest prevalence of infection was found in weaning lambs (6.8%). Among the different seasons, the peaks were found in the fall and winter. The most prevalent species were C. xiaoi and C. ubiquitum, with the former accounting for the majority of infections. The distribution of C. xiaoi subtypes was diverse, with XXIIIc (n = 1), XXIIId (n = 2), XXIIIe (n = 2), and XXIIIl (n = 4) identified. In contrast, only one subtype, XIIa (n = 9), was found in C. ubiquitum. In this study, C. xiaoi and C. ubiquitum were found to be the predominant species, and Cryptosporidium was found to be present in the environment. These findings provide an important foundation for the comprehensive prevention and management of Cryptosporidium in intensively reared sheep. Furthermore, by elucidating the prevalence of Cryptosporidium in sheep and its potential role in environmental transmission, this study deepens our understanding of the intricate interactions between animal health, environmental contamination, and public health dynamics.

Prevalence of Cryptosporidium spp. in Sheep and Goats in Jiangsu, China

Sheep and goats serve as crucial hosts for Cryptosporidium spp. and are primarily responsible for its transmission via the fecal-oral route. This can result in symptoms such as lamb weight loss, diarrhea, and even fatalities, leading to significant economic losses. Currently, there is a lack of scholarly research investigating the prevalence of Cryptosporidium spp. infection in sheep and goats specifically within Jiangsu province. This study collected fecal samples from sheep and goats, extracted their DNA, amplified target bands using nested PCR, sequenced the DNA, constructed a phylogenetic tree, and identified the genetic genotype. In total, 3 positive samples were identified out of 398 samples. Furthermore, the gene sequences of these samples exhibited significant homology with C. xiaoi in GenBank. The phylogenetic analysis revealed that the Cryptosporidium spp. parasites under investigation are phylogenetically related to C. xiaoi. Conducting epidemiological investigations and accurately identifying the species of Cryptosporidium spp. is of utmost importance not only for the mutton sheep farming industry in Jiangsu but also for the proactive safeguarding of human health.

First Detection of Cryptosporidium parvum in the Endemic Cyprus Mouflon (Ovis gmelini ophion)

PURPOSE

Cryptosporidium is an intestinal zoonotic protozoan parasite that infects domesticated and wild animals. There are no reports on the prevalence and molecular characterisation of Cryptosporidium in the endemic Cyprus mouflon. The mouflon is strictly protected by national and international legislation. Its main distribution is Paphos State Forest and surrounding areas, where it may share the same water sources as free-ranging domestic goats. Therefore, the present study aimed to determine the prevalence of Cryptosporidium spp. and genotypes in mouflon and free-ranging goats within the mouflon range.

METHODS

Faecal samples of 70 mouflons and 34 free-ranging goats were screened for Cryptosporidium by PCR amplification and sequencing.

RESULTS

Only one sample (1/70) belonging to a mouflon was PCR positive for Cryptosporidium. Based on sequencing of the 18S rRNA locus, this species was identified as Cryptosporidium parvum (C. parvum). No positive sample was detected in the free-ranging goats (0/34).

CONCLUSION

This is the first report on the molecular identification of this Cryptosporidium species in a Cyprus mouflon. The results indicate that the prevalence of Cryptosporidium in Cyprus mouflon is low.

Molecular evaluation of Cryptosporidium spp. in sheep in southern Xinjiang, China

Cryptosporidium spp. are diarrheagenic intestinal parasites with multiple hosts worldwide. A total of 1252 fresh fecal samples of sheep were collected from 10 large-scale farms in southern Xinjiang. Based on the small subunit ribosomal (SSU rRNA) gene of Cryptosporidium, 100 Cryptosporidium-positive samples (8.0%, 100/1252) were detected by PCR. Nine out of 10 farms were positive for Cryptosporidium, with the highest infection rate being 18.4% (23/125) on farm 9 in Qira. The infection rates of Cryptosporidium in pre-weaned lambs, weaned lambs, fattening sheep, and adult sheep were 20.3% (61/301), 10.3% (34/329), 0.9% (3/327), and 0.7% (2/295), respectively. Three Cryptosporidium species were identified, namely, C. xiaoi (n = 61), C. parvum (n = 22), and C. ubiquitum (n = 17). Of them, C. xiaoi was detected on all positive farms and in different age groups of sheep. The subtypes of C. parvum and C. ubiquitum were identified by PCR at the 60 kDa glycoprotein (gp60) gene. Two C. parvum subtypes were identified: IIdA19G1 (n = 21) and IIdA15G1 (n = 1). One C. ubiquitum subtype was identified with XIIa (n = 17). These results indicated the common transmission and genetic diversity of Cryptosporidium in sheep in southern Xinjiang, and further investigations are needed on the zoonotic potential of C. parvum and C. ubiquitum in this region.

Molecular Characterization of Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and Escherichia coli in Dairy Goat Kids with Diarrhea in Partial Regions of Shaanxi Province, China

Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and Escherichia coli are important diarrheal pathogens threatening the health of humans and various animals. Goats, especially pre-weaned goat kids, that carry these pathogens are important reservoirs related to human infection. In the present study, PCR-based sequencing techniques were applied to characterize Cryptosporidium spp., G. duodenalis, E. bieneusi and E. coli in 202 fecal samples of diarrheal kids for Guanzhong dairy goats from five locations in Shaanxi Province. The positive rates of Cryptosporidium spp., G. duodenalis, E. bieneusi and E. coli were 37.6% (76/202), 16.3% (33/202), 55.4% (112/202) and 78.7% (159/202) in these goat kids, respectively. Co-infection of two to four pathogens was found in 114 of 202 fecal samples. Significant differences (p < 0.001) in the positive rates of Cryptosporidium spp. and G. duodenalis were found among locations and age groups. Furthermore, two Cryptosporidium species (C. parvum and C. xiaoi), two G. duodenalis assemblages (E and A), nine E. bieneusi genotypes (CHG3, CHG1, BEB6, CHG5, CHG2, SX1, CHG28, COS-II and CD6) and two E. coli pathotypes (EPEC and EHEC) were identified. As for Cryptosporidium, two (IIdA19G1 and IIdA19G2) and two (XXIIIa and XXIIIg) subtypes were recognized in samples positive for C. parvum and C. xiaoi, respectively. A phylogenetic analysis based on the ITS locus of E. bieneusi indicated that all nine genotypes of E. bieneusi identified in this study belonged to the group 2. Four virulence factors (ehxA, eae, stx2 and stx1) of EPEC and EHEC were found in E. coli strains. Collectively, this study explored the colonization frequency of Cryptosporidium spp., G. duodenalis, E. bieneusi and E. coli in diarrheal kids of Guanzhong dairy goats in Shaanxi Province and expanded our understanding of the genetic composition and zoonotic potential of these pathogens in goats.

Meta-analysis of the prevalence of Giardia duodenalis in sheep and goats in China

Giardia duodenum (G. duodenalis) can cause giardiasis and infect a variety of hosts. So far, there have been no detailed data regarding the positive rate of G. duodenalis in sheep and goats in China. Here, a systematic literature review was carried out to investigate the epidemiology of G. duodenalis in sheep and goats in China. To perform the meta-analysis, the databases CNKI, VIP, WanFang, PubMed, Web of science and ScienceDirect were employed for screening studies related to the prevalence of G. duodenalis in sheep and goats in China. The total prevalence of G. duodenalis in sheep and goats was estimated to be 7.00% (95% CI: 4.00-10.00). In the age subgroup, the prevalence of G. duodenalis in sheep and goats of >12 months (11.29%; 95% CI: 8.08-14.97) was higher than that in sheep and goats of ≤12 months (7.57%; 95% CI: 3.95-12.24). An analysis based on seasons showed that the prevalence of G. duodenalis in sheep and goats was higher in summer (11.90%; 95% CI: 0.50-35.05) than that in other seasons. The prevalence of G. duodenalis in sheep and goats after 2016 was 8.57% (95% CI: 5.34-11.79), which was higher than others. The highest prevalence of G. duodenalis in sheep and goats was 13.06% (95% CI: 6.26-19.86) recorded in Southwestern China. The prevalence of Giardia infection in sheep (7.28%; 95% CI: 2.30-14.73) was higher than that in goats (5.43%; 95% CI: 2.73-8.98). The NOAA's National Center for Environmental Information (https://gis.ncdc.noaa.gov/maps/ncei/cdo/monthly) was used to extract relevant geoclimatic data (latitude, longitude, elevation, temperature, precipitation, humidity, and climate). By analyzing the data of each subgroup, it was shown that region, genetype, and climate were potential risk factors for giardiasis prevalence in sheep and goats. Based on the analysis of common factors and geographical factors, it is recommended to strengthen effective management measures (e.g. ventilation and disinfection in warm and humid areas) and formulate relevant policies according to local conditions. Breeders should strengthen the detection of G. duodenalis in sheep and goats, customize corresponding control measures according to the diet and living habits of sheep and goats, and strengthen the protection of sheep and lamb calves, so as to reduce the incidence rate and reduce the economic loss of China's animal husbandry.

Seasonal distribution of Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi in Tibetan sheep in Qinghai, China

Background

Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi can cause important intestinal diseases in ruminants. However, data on the distribution of these three protozoan pathogens in Tibetan sheep are limited.

Methods

We collected 761 fecal samples from Tibetan sheep across four seasons in Qinghai Province, China, and screened the samples for Cryptosporidium spp., G. duodenalis and E. bieneusi using PCR-based sequence analysis of the genes encoding 18S ribosomal RNA, triosephosphate isomerase and the internal transcribed spacer, respectively.

Results

The positivity rates of Cryptosporidium spp., G. duodenalis and E. bieneusi in Tibetan sheep were 3.68% (28/761 samples), 1.58% (12/761) and 6.44% (49/761), respectively. Four species of Cryptosporidium were identified: C. xiaoi (n = 13 samples), C. ubiquitum (n = 8), C. bovis (n = 6) and C. ryanae (n = 1). Two G. duodenalis assemblages, namely the A (n = 2 samples) and E (n = 10) assemblages, were detected. Five zoonotic E. bieneusi genotypes were found: BEB6 (n = 21 samples), COS-I (n = 14), CHS3 (n = 11) and CGS1 (n = 2) from group 2, and PIGEBITS5 (n = 1) from group 1. Geographic differences in the distribution of E. bieneusi, and seasonal differences for all the three protozoan pathogens were noted.

Conclusions

Our results elucidate the prevalence and genetic diversity of these three pathogens in Tibetan sheep across different regions and seasons, including zoonotic pathogens such as C. ubiquitum, C. ryanae, G. duodenalis assemblage A and five genotypes of E. bieneusi.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05442-0.

Molecular Identification and Genotyping of Enterocytozoon bieneusi in Sheep in Shanxi Province, North China

Enterocytozoon bieneusi is a fungus-like protist that can cause malabsorption and diarrhea in sheep, other animals, and humans, threatening the development of animal husbandry and public health. To date, there are no data about the prevalence and genotypes of E. bieneusi in sheep in Shanxi Province, North China. In this study, 492 fecal samples were collected from sheep in three representative counties in northern, central, and southern Shanxi Province. Nested PCR amplification was performed to detect the prevalence and identify the genotypes of E. bieneusi based on the internal transcribed spacer (ITS) region of the rRNA gene. Overall, 168 of 492 examined samples were E. bieneusi-positive, with a prevalence of 34.2% (168/492). Significant differences in the prevalence of E. bieneusi were observed among the three sampled regions (χ2 = 95.859, df = 2, p < 0.001), but the differences in E. bieneusi prevalence were not statistically significant between different genders and age groups (p > 0.05). Sequence analysis showed that four known genotypes (BEB6, COS-I, CHS7, and CHC8) and one novel genotype (named SY-1) were identified. BEB6 was the prevalent genotype found within the three counties. Phylogenetic analysis revealed that the five genotypes observed in this study belong to Group 2. The present study reported the presence and genotypes of E. bieneusi infection in sheep in Shanxi Province for the first time, which enriches the knowledge of the genetic diversity of E. bieneusi and provides baseline data for the prevention and control of E. bieneusi infection in animals and humans.

Clinical cases of zoonotic Cryptosporidium parvum (subtype IIdA15G1) infections in Korean goats

Cryptosporidium parvum is an enteric protozoan, which causes severe diarrhoea in a wide range of vertebrate hosts including ruminants and humans. C. parvum infections are responsible for immense economic losses to the livestock industry; furthermore, the zoonotic spread of the infection may lead to mortality in immunosuppressed humans. In the present study, we report two cases of severe cryptosporidiosis in goat kids in the Republic of Korea. Both cases were afflicted with severe diarrhoea upon presentation; the histopathological examinations revealed atrophied and fused intestinal villi and numerous circular basophilic organisms in the jejunum and ileum. Both cases were diagnosed with cryptosporidiosis based on the results of the histopathological analysis, amplification of the C. parvum gp60 gene, modified Ziehl-Neelsen staining, and C. parvum antigen ELISA. According to the phylogenetic analysis using the C. parvum gp60 gene for the genetic subtypes, the C. parvum isolates were identified as subtype IIdA15G1 with zoonotic potential. This is the first pathological report of caprine cryptosporidiosis induced by C. parvum subtype IId in the Republic of Korea. Considering the clinical manifestations associated with the pathological lesions and the zoonotic significance of these findings, the continuous monitoring and prevention of C. parvum infections in goats are essential for minimising the economic losses in ruminant farms and in maintaining public health safety standards.

Emergence of zoonotic Cryptosporidium parvum in China

Zoonotic cryptosporidiosis is a major public health problem in industrialized nations; in those countries it is caused mainly by Cryptosporidium parvum IIa subtypes that are prevalent in dairy calves. Because of the short history of intensive animal farming in China, strains of C. parvum are found only on some dairy farms in this country and are the IId subtypes. However, the prevalence of C. parvum is increasing rapidly, with IIa subtypes recently detected in a few grazing animals, and both IIa and IId subtypes are emerging in humans. As animal farming intensifies, China may follow in the footsteps of industrialized nations where zoonotic cryptosporidiosis is rampant. One Health and biosecurity measures are urgently needed to slow down the dispersal of autochthonous IId subtypes and imported IIa subtypes.

Prevalence and Characterization of Cryptosporidium Species in Tibetan Antelope (Pantholops hodgsonii)

Cryptosporidium is an enteric apicomplexan parasite, which can infect multiple mammals including livestock and wildlife. Tibetan Antelope (Pantholops hodgsonii) is one of the most famous wildlife species, that belongs to the first class protected wild animals in China. However, it has not been known whether Tibetan Antelope is infected with Cryptosporidium so far. The objective of the present study was to determine the prevalence and characterization of Cryptosporidium species infection in Tibetan Antelope and the corresponding species by using molecular biological method. In the current study, a total of 627 fecal samples were randomly collected from Tibetan Antelope in the Tibet Autonomous Region (2019–2020), and were examined by PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene. Among 627 samples, 19 (3.03%, 19/627) were examined as Cryptosporidium-positive, with 7 (2.33%, 7/300) in females and 12 (3.67%, 12/327) in males. The analysis of SSU rRNA gene sequence suggested that only two Cryptosporidium species, namely, C. xiaoi and C. ubiquitum, were identified in this study. This is the first evidence for an existence of Cryptosporidium in Tibetan Antelope. These findings extend the host range for Cryptosporidium spp. and also provide important data support for prevention and control of Cryptosporidium infection in Tibetan Antelope.

Prevalence of Cryptosporidium Infection in Sheep and Goat Flocks in China During 2010-2019: A Systematic Review and Meta-Analysis

Cryptosporidiosis is an extensively contagious zoonotic waterborne disease caused by the genus Cryptosporidium and poses to be a danger to public health. Sheep and goats are an intermediate host of Cryptosporidium. Consequently, a first systematic review and meta-analysis are performed to assess the burden of the infection relative to the Cryptosporidium in sheep and goat flocks in China. Five databases were searched for relevant literature in accordance with the inclusion criteria until January 30, 2020. At last, a total of 33 qualified documents were included. We calculate the overall prevalence of Cryptosporidium (4.9%) in sheep and goats in China with the random-effects model. The prevalence after 2014 (4.6%) was higher than that before or in 2014 (2.8%). The pooled prevalence of Cryptosporidium in sheep and goats from Northern China (12.3%) was significantly higher (p < 0.05) than other regions. The infection rate of modified acid-fast staining (14.3%) was the highest among the detection methods. In age subgroups, the prevalence of Cryptosporidium in sheep and goats in 3 months or before was the highest (20.8%). Goats had a higher infection rate (5.9%) in species. The prevalence of large-scale farms (2.8%) was lower than free-ranging farms (4.4%). The medium quality level (6.4%) was the highest. Besides, geographical factors (such as latitude, longitude, height, precipitation, humidity, mean temperature, etc.) were further analyzed as potential risk factors of Cryptosporidium in sheep and goats. This meta-analysis indicates that the Cryptosporidium infection of Chinese sheep and goat flocks is general. Thus, it is necessary to further monitor the prevalence of Cryptosporidium, and the reasonable preventive strategy should be formulated on the basis of the geographical factors of different regions and the differences in sheep and goats' growth stages to reduce the prevalence of Cryptosporidium in sheep and goats.

Molecular epidemiology and genotype/subtype distribution of Blastocystis sp., Enterocytozoon bieneusi, and Encephalitozoon spp. in livestock: concern for emerging zoonotic infections

Intestinal parasitic infections have high prevalence rate in many regions especially in developing countries. The aim of this study was to determine the presence and genotype/subtype of some intestinal protozoa in livestock in Iran. Stool samples were collected from cattle, sheep, chickens, and horses. The presence of targeted parasites was evaluated using real-time PCR. Genotyping/subtyping of positive samples was characterized using sequencing of the ITS and barcoding region, respectively. Blastocystis sp., 27.7% (48/173) and Enterocytozoon bieneusi 26.0% (45/173) were the most frequent protozoa followed by Encephalitozoon spp., 0.57% (1/173). Cryptosporidium spp. were not detected among samples. Encephalitozoon spp., was detected only in chickens 2.2% (1/45). A statistically correlation was seen between animals and the prevalence of targeted protozoa. E. bieneusi genotypes I (9/38; 23.68%), BEB6 (22/38; 57.89%), D (6/38; 15.79%), and horse1 (1/38; 2.63%) were detected among samples. A statistically significant correlation was seen between the genotypes and animals (P ≤ 0.05). Blastocystis sp., ST1 (1/45; 2.22%), ST5 3/45; 6.66%), ST7 (1/45; 2.22%), ST10 (24/45; 53.33%), and ST14 (16/45; 35.55%) were characterized among samples. There was no significant correlation between certain subtypes and animals (P = 0.173). The presence of zoonotic potential genotypes of E. bieneusi in animals and zoonotic potential subtypes ST1 and ST7 among our samples provide a clue about the transmission dynamic of E. bieneusi and Blastocystis sp. between animals–animals and humans–animals.

The global molecular epidemiology of microsporidia infection in sheep and goats with focus on Enterocytozoon bieneusi: a systematic review and meta-analysis

BACKGROUND

Microsporidia is a zoonotic pathogen with health consequences in immunocompromised patients. Small ruminants are a potential reservoir of microsporidia for humans in their vicinity. Hence, we aimed to evaluate the molecular prevalence of microsporidian infections with emphasis on Enterocytozoon bieneusi genotypes among sheep and goats at a global scale through systematic review and meta-analysis approach.

METHODS

The standard protocol of preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Eligible prevalence studies on small ruminant microsporidiosis, published from 1 January 2000 until 15 April 2021 were gathered using systematic literature search in PubMed, Scopus, Web of Science and Google Scholar databases. Inclusion and exclusion criteria were applied. The point estimates and 95% confidence intervals were calculated using a random-effects model. The variance between studies (heterogeneity) was quantified by I² index.

RESULTS

In total, 25 articles (including 34 datasets) were included for final meta-analysis. The pooled molecular prevalence of microsporidia in sheep and goats was estimated to be 17.4% (95% CI: 11.8-25%) and 16% (95% CI: 11.2-22.4%), respectively. Likewise, the overall prevalence of E. bieneusi was estimated to be 17.4% (95% CI: 11.8-25%) for sheep and 16.3% (95% CI: 11.3-22.8%) for goats. According to internal transcribed spacer (ITS) gene analysis, E. bieneusi with genotypes BEB6 (15 studies) and COS-1 (nine studies) in sheep, and CHG3 (six studies) and BEB6 (five studies) in goats were the highest reported genotypes.

CONCLUSION

The present results highlight the role of sheep and goats as reservoir hosts for human-infecting microsporidia. Therefore, this global estimate could be beneficial on preventive and control measures.

Occurrence of Cryptosporidium and Giardia in wild birds from Qinghai Lake on the Qinghai-Tibetan Plateau, China

Cryptosporidium and Giardia are important intestinal zoonotic pathogens that can infect various hosts and cause diarrhoeal diseases. There are few reports of the epidemiological prevalence and molecular characterization of Cryptosporidium and Giardia in wild birds around Qinghai Lake and in the surrounding areas on the Qinghai-Tibetan Plateau, Northwest China. Therefore, the aim of this study was to determine the Cryptosporidium spp. and Giardia duodenalis genotypes and their epidemiological prevalence in wild birds by PCR amplification. To our knowledge, this is the first report of a variety of Cryptosporidium spp. and G. duodenalis infections in wild birds from that area, with overall prevalence rates of 8.98% (61/679) and 3.39% (23/679), respectively. Furthermore, PCR sequencing confirmed the presence of Cryptosporidium baileyi (n = 3), Cryptosporidium parvum (n = 58), and G. duodenalis assemblage B (n = 19) and E (n = 4) in wild birds from the areas around Qinghai Lake. The results of the present study demonstrated the wide distribution of Cryptosporidium and Giardia among wild birds, which has potential public health significance. Moreover, the study findings also provided useful molecular epidemiological data for monitoring and investigating the two parasitic protozoa in wild animals and surrounding environments.

Cryptosporidium infections in sheep farms from Italy

Cryptosporidiosis is recognized as being a significant cause of gastrointestinal illness due to its wide range of vertebrate hosts, including humans. Infection with Cryptosporidium spp. is especially common in young domestic ruminants (calves, lambs and goat kids) and has been associated with economic losses worldwide. In contrast to cattle, to date, detailed studies on Cryptosporidium infections in sheep from Europe are still limited; thus, their importance as reservoirs of Cryptosporidium species with implications on animal and public health still needs to be clarified. This study evaluates the prevalence and zoonotic potential of Cryptosporidium spp. in sheep farms in Italy. A total of 915 individual faecal samples divided into three different animal categories were collected from 61 sheep farms. Each sample was examined by microscopy of faecal smears stained by modified Ziehl-Neelsen and by biomolecular techniques. Cryptosporidium oocysts were detected in 10.1% of the animals examined and in 34.4% of the farms. The prevalence of Cryptosporidium spp. was significantly higher (χ² = 51.854; P < 0.001) in diarrhoeic samples than in pasty or normal faeces. Genotype analyses showed the presence of two Cryptosporidium species: C. parvum and C. ubiquitum. Subtyping analysis of C. parvum isolates revealed the presence of subtypes IIa15G2R1 and IIdA20G1 and of subtype XIIa for C. ubiquitum. These findings have public health implications since both Cryptosporidium species identified are considered zoonotic, and C. parvum is the second-most common Cryptosporidium species infecting humans. Our data reveal that lambs, especially those excreting diarrhoeic faeces, may be important reservoirs of Cryptosporidium. We also highlight the need to establish adequate control and monitoring programmes for the control of this infection in sheep farms primarily through coprological monitoring.

Diagnosis and molecular typing of Enterocytozoon bieneusi: the significant role of domestic animals in transmission of human microsporidiosis

Enterocytozoon bieneusi is an obligate intracellular fungus-like parasite with high genetic diversity among mammalian and avian hosts. Based on polymorphism analysis of the ribosomal internal transcribed spacer (ITS), nearly 500 genotypes were identified within E. bieneusi. Those genotypes form several genetic groups that exhibit phenotypic differences in host specificity and zoonotic potential and probably have varying public health implications. Some of the genotypes in Group 1 (e.g., D, EbpC, and Type IV) and Group 2 (e.g., BEB4, BEB6, I, and J) are the most common ones that infect a variety of hosts including humans and thus are of public health importance. By contrast, those genotypes in other genetic groups (Groups 3-11) are mostly restricted to the hosts from which they were originally isolated, which would have unknown or limited impacts on public health. Advances on diagnosis and molecular typing of E. bieneusi are introduced in this review. Genotype distribution pattern of E. bieneusi in major domestic animal groups (pigs, cattle, sheep, goats, cats, and dogs), the role of those animals in zoonotic transmission of microsporidiosis, and food and water as potential vehicles for transmission are interpreted here as well. This review highlights the importance of including more genetic or epidemiological data obtained in the same geographical areas and using more reliable genetic markers to analyze the actual extent of host specificity in E. bieneusi, for the purpose of fully appreciating zoonotic risks of those domestic animals in close contacts with men and enhancing our understanding of the modes of transmission.

Prevalence and molecular characterization of Cryptosporidium spp. in pigs in Xinjiang, China

Cryptosporidium spp. are distributed ubiquitously worldwide, and pigs are considered as one of the main reservoir hosts. Eight hundred one porcine fecal specimens were collected from seven intensive pig farms in Xinjiang Uygur Autonomous Region, China. Cryptosporidium spp. were screened via PCR amplification of the small ribosomal subunit RNA gene, and 143 specimens (17.9%, 143/801) from all seven farms tested positive for Cryptosporidium spp. Cryptosporidium prevalence in the pigs differed significantly among farms (p < 0.01). The highest Cryptosporidium spp. prevalence in post-weaned pigs was 39.5% (111/281), followed by fattening pigs (23.2%, 30/129), pre-weaned pigs (1.2%, 2/169), and sows (0/222). Significant differences were observed between age groups (p < 0.01). C. suis was the predominantly identified species (62.9%, 90/143), followed by C. scrofarum (35.7%, 51/143), and C. parvum (1.4%, 2/143). Two C. parvum specimens were subtyped by analyzing the 60-kDa glycoprotein (gp60) gene sequences and were identified as IIdA14G1 and IIdA15G1. To our knowledge, this is the first report of C. parvum infection in pigs in China. The identification of three Cryptosporidium species, including zoonotic C. parvum in pigs in Xinjiang raises concern for the health of both swine animals and personnel in the pig industry.

Occurrence and molecular characterization of Giardia duodenalis in lambs in Djelfa, the central steppe of Algeria

Little is known of the prevalence and genetic identity of Giardia duodenalis in sheep in Algeria. The present study aimed at characterizing G. duodenalis in lambs up to 6 months of age in Djelfa, Algeria. A total of 346 fecal specimens were collected from 28 farms and screened for G. duodenalis cysts by zinc sulfate flotation microscopy, and positive specimens were confirmed using a direct immunofluorescence assay. Microscopy-positive specimens were analyzed by PCR and sequence analysis of the triosephosphate isomerase and glutamate dehydrogenase genes to determine G. duodenalis assemblages. Coprological examination indicated that the overall infection rate was 7.0% (24/346). Lambs under 3 months of age had higher infection rate (18/197, 9.0%) than older (6/149, 4.0%) animals, and animals with diarrhea (7/44, 16.0%) had higher infection rate than animals without diarrhea (17/302, 5.6%). PCR sequence analyses of the 15 G. duodenalis isolates revealed the presence of assemblages A in 6 isolates, assemblage E in 7 isolates, and both in 2 isolates. Assemblage A was only found in pre-weaned lambs with diarrhea, while assemblage E was mostly found in post-weaned lambs without diarrhea. The assemblage E isolates from sheep were genetically related to those from cattle in Algeria, while assemblage A isolates were from a well-known subtype prevalent in humans. Data generated from the study improve our understanding of the transmission of G. duodenalis in Algeria.

First report of Cryptosporidium spp. infection and risk factors in black-boned goats and black-boned sheep in China

Cryptosporidium is an opportunistic protozoan parasite that can inhabit in the gastrointestinal tract of various hosts. Cryptosporidium infection in black-boned goats and black-boned sheep may pose a threat to the survival and productivity, causing considerable economic losses to the livestock industry. However, it is yet to know whether black-boned goats and black-boned sheep in China are infected with Cryptosporidium. Thus, the objective of the present study was to investigate the prevalence and associated risk factors of Cryptosporidium infection in black-boned goats and black-boned sheep in Yunnan province, China. A total of 590 fecal samples were obtained from black-boned goats and black-boned sheep from five counties in Yunnan province, and the prevalence and species distribution of Cryptosporidium were determined by amplification of the 18S rDNA fragment using the nested PCR. The overall Cryptosporidium prevalence was 13.2% (78/590), with 18.0% (55/305) in black-boned goats and 8.1% (23/285) in black-boned sheep. The age and sampling site were identified as main factors that result in significant differences in Cryptosporidium prevalence. Three species, namely C. muris, C. xiaoi, and C. ubiquitum, were identified in black-boned goats and black-boned sheep in the present study, with C. muris (46/78) as the predominant species. This is the first report of Cryptosporidium infection in black-boned goats and black-boned sheep in China, and the findings will facilitate better understanding, prevention, and control of Cryptosporidium infection in black-boned goats and black-boned sheep in China.

Detection and genotyping of Giardia duodenalis from cattle and pigs in Hualien country, Eastern Taiwan

BACKGROUND

Giardia duodenalis is a zoonotic protozoan parasite causing diarrhea through waterborne or fecal-oral infection. The cysts can live in the drinking water and cause pandemic diseases. In Taiwan, very little information is available regarding the epidemiology of G. duodenalis in domestic animals.

METHODS

Fecal samples were collected from cattle (n = 156) and pigs (n = 141) in Hualien country, eastern Taiwan. Detection and genotyping were done by microscopy examination of fecal samples and amplification of the β-giardin gene using nested PCR.

RESULTS

The prevalence of G. duodenalis infection was 19.87% for cattle (31/156) and 4.26% for pigs (6/141). Using nested PCR, 30 infected samples found in cattle belonged to Assemblage E, and one sample belonged to Assemblage D. For pigs, four samples belonged to Assemblage E, one belonged to Assemblage D, and another one belonged to Assemblage A. In addition, these results showed that G. duodenalis Assemblage A was detected in pigs and may cause zoonotic transmission.

CONCLUSION

This is the first epidemiological investigation of G. duodenalis infection in animals in Hualien, Taiwan. These results could provide epidemiological information for disease control and public health protection.