Cryptosporidium infection in livestock and first identification of Cryptosporidium parvum genotype in cattle feces in Taiwan

Prevalence and molecular characterization of Cryptosporidium spp. in dairy and beef cattle in Shanxi, China

Cryptosporidium spp. are key gastrointestinal protists in humans and animals worldwide. Infected cattle are considered the main source of cryptosporidiosis outbreaks in humans. However, little is known about the genetic makeup of Cryptosporidium populations in Shanxi province, China. We analyzed 858 fecal samples collected from farms in Shanxi. The presence of Cryptosporidium spp. was determined via polymerase chain reaction and subsequent sequence analysis of the small subunit rRNA gene as well as restriction fragment length polymorphism analysis. Cryptosporidium parvum was subtyped following sequence analysis of the 60 kDa glycoprotein gene (gp60). The overall prevalence of Cryptosporidium in cattle was 11.19%, with a prevalence of 13.30% and 8.67% in Lingqiu and Yingxian, respectively. The overall prevalence of Cryptosporidium in dairy and beef cattle was 10.78% and 11.50%, respectively. Cryptosporidium infection was detected across all analyzed age groups. The overall prevalence of Cryptosporidium in diarrhea and nondiarrhea samples was 18.24% and 9.72%, respectively, whereas that in intensively farmed and free-range cattle was 17.40% and 3.41%, respectively. We identified five Cryptosporidium species, with C. andersoni being the dominant species. Further, two cases of mixed infections of Cryptosporidium species were detected. All identified C. parvum isolates belonged to the subtype IIdA17G1.

Prevalence and molecular characterization of Cryptosporidium spp. in dairy cattle in Central Inner Mongolia, Northern China

BACKGROUND

Cryptosporidium is a gastrointestinal protozoan that widely exists in nature, it is an established zoonotic pathogen. Infected cattle are considered to be associated with cryptosporidiosis outbreaks in humans. In the present study, we aimed to assess the prevalence and species distribution of Cryptosporidium in dairy cattle in Central Inner Mongolia.

METHODS

We focused on the small subunit ribosomal RNA gene (SSU rRNA) of Cryptosporidium and 60-kDa glycoprotein gene (gp60) of Cryptosporidium parvum. We collected 505 dairy cattle manure samples from 6 sampling sites in Inner Mongolia in 2021; the samples were divided into 4 groups based on age. DNA extraction, polymerase chain reaction (PCR), sequence analysis, and restriction fragment length polymorphism (RFLP) using SspI and MboII restriction endonucleases were performed. RFLP analysis was performed to determine the prevalence and species distribution of Cryptosporidium.

RESULTS

SSU rRNA PCR revealed that the overall prevalence of Cryptosporidium infection was 29.90% (151/505), with a prevalence of 37.67% (55/146) and 26.74% (96/359) in diarrheal and nondiarrheal samples, respectively; these differences were significant. The overall prevalence of Cryptosporidium infection at the 6 sampling sites ranged from 0 to 47.06% and that among the 4 age groups ranged from 18.50 to 43.81%. SSU rRNA sequence analysis and RFLP analysis revealed the presence of 4 Cryptosporidium species, namely, C. bovis (44.37%), C. andersoni (35.10%), C. ryanae (21.85%), and C. parvum (11.92%), along with a mixed infection involving two or three Cryptosporidium species. Cryptosporidium bovis or C. andersoni was the most common cause of infection in the four age groups. The subtype of C. parvum was successfully identified as IIdA via gp60 analysis; all isolates were identified as the subtype IIdA19G1.

CONCLUSIONS

To the best of our knowledge, this is the first report of dairy cattle infected with four Cryptosporidium species in Inner Mongolia, China, along with a mixed infection involving two or three Cryptosporidium species, with C. bovis and C. andersoni as the dominant species. Moreover, this is the first study to identify C. parvum subtype IIdA19G1 in cattle in Inner Mongolia. Our study findings provide detailed information on molecular epidemiological investigation of bovine cryptosporidiosis in Inner Mongolia, suggesting that dairy cattle in this region are at risk of transmitting cryptosporidiosis to humans.

Past, current, and potential treatments for cryptosporidiosis in humans and farm animals: A comprehensive review

The intracellular protozoan parasite of the genus Cryptosporidium is among the leading causes of waterborne diarrheal disease outbreaks throughout the world. The parasite is transmitted by ingestion of infective oocysts that are highly stable in the environment and resistant to almost all conventional disinfection methods and water treatments. Control of the parasite infection is exceedingly difficult due to the excretion of large numbers of oocysts in the feces of infected individuals that contaminate the environment and serve as a source of infection for susceptible hosts including humans and animals. Drug development against the parasite is challenging owing to its limited genetic tractability, absence of conventional drug targets, unique intracellular location within the host, and the paucity of robust cell culture platforms for continuous parasite propagation. Despite the high prevalence of the parasite, the only US Food and Drug Administration (FDA)-approved treatment of Cryptosporidium infections is nitazoxanide, which has shown moderate efficacy in immunocompetent patients. More importantly, no effective therapeutic drugs are available for treating severe, potentially life-threatening cryptosporidiosis in immunodeficient patients, young children, and neonatal livestock. Thus, safe, inexpensive, and efficacious drugs are urgently required to reduce the ever-increasing global cryptosporidiosis burden especially in low-resource countries. Several compounds have been tested for both in vitro and in vivo efficacy against the disease. However, to date, only a few experimental compounds have been subjected to clinical trials in natural hosts, and among those none have proven efficacious. This review provides an overview of the past and present anti-Cryptosporidium pharmacotherapy in humans and agricultural animals. Herein, we also highlight the progress made in the field over the last few years and discuss the different strategies employed for discovery and development of effective prospective treatments for cryptosporidiosis.

Cryptosporidium parvum infection and management-based risk factors of dairy calves in Taiwan

Cryptosporidiosis is one of the major causes of diarrhea in calves. Cryptosporidium parvum is considered the most important calf diarrhea pathogen in the Cryptosporidium species. Not only could infected calves spread C. parvum, but infected adult cattle could also shed oocysts. The objectives of this study were (1) to investigate the prevalence of C. parvum in dairy herds in Taiwan, including calves, the dams in delivery enclosure, the floor, and the drinking water; (2) to clarify the relationship of diarrhea, management, and C. parvum infection. Twenty dairy herds in Taiwan were selected by random sampling, including 226 calves and 198 dams, and other environmental samples were collected. A questionnaire was filled out by the farm owners to collect information regarding the management of calves and the delivery enclosure. Hierarchical logistic regression was used to analyze the risk factors for C. parvum infection. The prevalence of C. parvum infection in calves was 26.5% (60/226), while in dams, it was 19.7% (39/198). The C. parvum infection in calves increased with environmental contamination of C. parvum and clinical signs of diarrhea, while it decreased with a yard provided in the delivery enclosure. In conclusion, the management of the delivery enclosure appears to be more important for preventing cryptosporidiosis in calves in Taiwan.

Advances and Perspectives on the Epidemiology of Bovine Cryptosporidium in China in the Past 30 Years

Major progress has been made in understanding the epidemiology of bovine Cryptosporidium in China in the past 30 years. The overall infection rate in that period was 14.50% (5265/36316), with different prevalence being observed among dairy cattle, yaks, beef cattle, and buffalo. The infection rate declined as the animals' ages increased and the lowest prevalence occurred in winter. Ten Cryptosporidium species and two genotypes have been found in cattle, with Cryptosporidium parvum, C. andersoni, C. bovis, and C. ryanae being the commonest species. Cryptosporidium bovis rather than C. parvum predominated in preweaned dairy cattle, and C. parvum IIdA15G1 and IIdA19G1 were the only subtypes detected in dairy cattle. Two subtype families, IIa and IId, were found in yaks. Population genetic analysis detected an epidemic population structure in C. andersoni, which suggested that the prevalence of C. andersoni in China is not attributable to the introduction of dairy cattle. Moreover, C. parvum IId subtypes probably dispersed from western Asia to other geographic regions based on population genetic analysis of isolates from China, Sweden, and Egypt. Therefore, we hypothesize that Cryptosporidium was introduced into China in the past, and different populations formed progressively in various hosts in response to diverse factors, including the transmission dynamics, geographic isolation, host specificity, and large-scale farming. More epidemiological studies are required to test this hypothesis and to clarify the prevalence and transmission of Cryptosporidium species in China.

Epidemiology of Cryptosporidium infection in cattle in China: a review

The present review discusses the findings of cryptosporidiosis research conducted in cattle in China and highlights the currently available information on Cryptosporidium epidemiology, genetic diversity, and distribution in China, which is critical to understanding the economic and public health importance of cryptosporidiosis transmission in cattle. To date, 10 Cryptosporidium species have been detected in cattle in China, with an overall infection rate of 11.9%. The highest rate of infection (19.5%) was observed in preweaned calves, followed by that in juveniles (10.69%), postweaned juveniles (9.0%), and adult cattle (4.94%). The dominant species were C. parvum in preweaned calves and C. andersoni in postweaned, juvenile, and adult cattle. Zoonotic Cryptosporidium species (C. parvum and C. hominis) were found in cattle, indicating the possibility of transmission between humans and cattle. Different cattle breeds had significant differences in the prevalence rate and species of Cryptosporidium. This review demonstrates an age-associated, breed-associated, and geographic-related occurrence of Cryptosporidium and provides references for further understanding of the epidemiological characteristics, and for preventing and controlling the disease.

Prevalence, molecular characterization and zoonotic potential of Cryptosporidium spp. in goats in Henan and Chongqing, China

To estimate the prevalence and public health significance of cryptosporidiosis in goats in China, 1265 fecal samples from seven farms in Henan province and Chongqing city were examined for Cryptosporidium oocysts. The overall infection rate of Cryptosporidium spp. was 3.48% (44/1256). Significant difference was observed among age groups, with the post weaned kids having the highest infection rate (4.58%; ρ<0.01). Cryptosporidium spp. were characterized by PCR-restriction fragment length polymorphism (RFLP) analysis and DNA sequence analysis of the small subunit (SSU) rRNA gene. The SSU rRNA-based PCR identified three Cryptosporidium species, including Cryptosporidium ubiquitum (24/44) in Henan and Chongqing, and Cryptosporidium andersoni (16/44) and Cryptosporidium xiaoi (4/44) in Henan. Among which, the C. ubiquitum and C. andersoni were first identified in goats thus far and were found in all age groups except no C. andersoni being found in the postparturition nannies, whereas the C. xiaoi was detected in pre-weaned kids and pregnant nannies. Subtyping C. ubiquitum by DNA sequence analysis of the 60 kDa glycoprotein (gp60) gene suggested the isolates identified all belonged to zoonotic XIIa subtype 2. Thus, the dominant C. ubiquitum found in this study and the XIIa subtype 2 has been found in humans indicated goats are a potential source for zoonotic infections with the C. ubiquitum. More studies are needed for better understanding of differences in the transmission and public health significance of cryptosporidiosis in goats.

Human cryptosporidiosis caused by Cryptosporidium tyzzeri and C. parvum isolates presumably transmitted from wild mice

We report a case of severe human cryptosporidiosis caused by Cryptosporidium tyzzeri and C. parvum with an unusually high frequency of liquid stools. Wild mice were the most likely source of infection, demonstrating the potential for wild-mouse-borne Cryptosporidium to infect humans and highlighting the health risks associated with synantropic rodents.

GiardiaandCryptosporidiuminfections in sheep and goats: a review of the potential for transmission to humans via environmental contamination

The public health significance of giardiasis and cryptosporidiosis in sheep is currently unclear. Some research suggests that they are probably not an important zoonotic reservoir, whilst other research indicates this potential exists, and some outbreaks have also been associated with infections in sheep. Actions to limit water supply contamination by sheep have sometimes been severe, occasionally creating problems between farming and public health communities. Here our knowledge on these parasites in both sheep and goats is reviewed; although direct evidence of transmission to humans via water supply contamination is limited, the data accrued indicate that this is a real possibility. As cryptosporidiosis in sheep is generally more prevalent than giardiasis, and species/genotypes ofCryptosporidiuminfections in sheep are likely to be infectious to humans, this parasite may be considered the greater threat. Nevertheless, geographical variation in prevalence and genotypic distribution is extensive and as measures to limit sheep grazing can have a highly negative impact, it is important that cases are judged individually. If water contamination from a particular population of sheep/goats is suspected, then suitable investigations should be instigated, investigating both prevalence and species/genotype, before precautionary measures are imposed.

Detection and species identification of Cryptosporidium from Taiwan feeding animals

In this study, 107 fecal specimens were collected from 40 sampling sites in Taiwan livestock and avian farms to test for Cryptosporidium spp. oocysts. Ten of 107 samples analyzed by enzyme-linked immunosorbent assay showed the presence of Cryptosporidium spp., among which 6 samples were simultaneously confirmed by immunofluorescence assay and polymerase chain reaction. Nucleic acid sequencing of the 18S rRNA gene identified 3 clusters of Cryptosporidium spp. Three Cryptosporidium parvum isolates were from cattle and sheep feces. One Cryptosporidium andersoni isolate was detected from pig feces. The other 2 novel Cryptosporidium genotypes were not similar to any known Cryptosporidium spp. according to the DNA sequences of the 18S rRNA gene.