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.

A 1-mo-old reticulated giraffe had progressive anorexia and died at the Ordos Zoo. Autopsy revealed necrotic stomatitis with severe bilateral necroulcerative lesions at the base of the tongue and of the cheeks near the commissures of the mouth. There was also severe bilateral confluent bronchopneumonia with a pronounced bronchial pattern and multifocal fibrinous pleuritis. Histologically, there was serofibrinous-suppurative bronchopneumonia with necrosuppurative bronchiolitis and necrotic arteritis. Filamentous bacteria with morphology consistent with Fusobacterium necrophorum were observed at the advancing edge of the necrotic tissue in the tongue and cheeks, as well as in the affected alveolar spaces and bronchioles. Aggregates of slender, gram-negative, rod-like or filamentous bacteria were identified in the lung impression smear. PCR results of 16S rDNA of the tongue and lung lesions had 100% homology to the F. necrophorum subsp. funduliforme B35 sequence (EF447425.1). The gross, histologic, Gram stain, and PCR product sequencing features in our case were consistent with oral and pulmonary necrobacillosis in ruminants, a rare disease of giraffes.

Duan X, et al. J Vet Sci. 2024 Aug;25:e61. https://doi.org/10.4142/jvs.24158