Prevalence and Population Genetics Analysis of Enterocytozoon bieneusi in Dairy Cattle in China.

Enterocytozoon bieneusi, an obligate intracellular pathogen, can infect various hosts. In this study, 3527 dairy cattle fecal specimens were collected from different geographic locations in China (including 673 from Shandong province, 1,440 from Guangdong province and 1,414 from Gansu province) and examined for the presence of E. bieneusi using polymerase chain reactions targeting the ribosomal internal transcribed spacer (ITS). The dominant genotypes identified were further subtyped by multilocus sequence typing. The overall prevalence of E. bieneusi was 14.2% (501/3527), with a significant difference in prevalence among the different geographical locations (P < 0.001). Our logistic regression analysis showed that all four variables (farming model, location, age, and clinical manifestations) had strong effects on the risk of contracting E. bieneusi. Sequence analysis revealed 11 genotypes: eight known genotypes (J, I, BEB4, BEB10, D, EbpC, CM19, and CM21) and three novel genotypes (named here as CGC1, CGC2, and CGC3). Genotypes J and I, the commonest, were found on all farms across the three provinces. Our linkage disequilibrium analysis showed a clonal population structure in the E. bieneusi dairy cattle population but the ITS genotypes had different population structures. Phylogenetic and haplotype network analysis showed the absence of geographical segregation in the E. bieneusi dairy cattle populations. Instead, they revealed the presence of host adaptation to the E. bieneusi populations in various animals. Our findings augment the current understanding of E. bieneusi transmission dynamics.

[Modified method for purifying Cryptosporidium oocysts].

Sheather's sucrose solution diluted with distilled water as an alternative to PBS was used to purify oocysts of three different Cryptosporidium spp. The recovery rate of purified Cryptosporidium andersoni, C. baileyi and C. suis oocysts was 47.5%, 49.6% and 41.7%, respectively. The viability of the oocysts was 97.9%, 96.7%, and 95.1%, respectively. After 1 h incubation in a 37 degrees C water bath, the excystation rate of the oocysts was 87.9%, 80.0%, and 81.7%, respectively.

[Investigation on the prevalence of gastrointestinal parasites in pet hamsters].

One hundred and fifty-three fecal samples of pet hamsters (Mesocricetus auratus, Phodopus sungorus, P. campbelli and P. roborovskii) were collected from a pet-market in Zhengzhou, and examined by Sheather's sugar flotation, modified acid-fast staining and Lugol's iodine-solution staining. The prevalence of parasites was 70.7% (41/58), 96.7% (59/61), 83.9% (26/31), and 100% (3/3) respectively, with an overall prevalence of 84.3%. Eggs, cysts or oocysts of Cryptosporidium sp. (15.0%), Giardia sp. (22.2%), coccidian (2.0%), Hymenolepis nana (31.4%), Hymenolepis diminuta (25.5%), Syphacia spp. (41.8%), Aspiculuris tetraptera (7.2%) and undetermined Trichurata nematode (18.3%) were found from the samples. The results suggest that pet hamsters may be infected and transmit several zoonotic parasites.

[Research progress on Cryptosporidium spp. and ovine/caprine cryptosporidiosis].

Cryptosporidiosis is a globally-distributed zoonosis, including in goats and sheep. This review summarizes recent findings in classification of Cryptosporidium spp., epidemiologic features, clinical symptoms and pathological change of cryptosporidiosis in goats and sheep.

[The advancement on mitochondrion of cryptosporidium].

Cryptosporidiosis is an important apicomplexan disease with medical and veterinary significance. There is still no effective drug for its control. Mitochondrion is an organelle which contains most protein and enzyme in eukaryotes, so the mitochondrion of Cryptosporidium may be a potential target of drugs. Recent studies provided evidence for a mitochondrial derived compartment in this parasite. But the organelle has some difference to that of other apicomplexan parasites. This organelle appears to lack its genome, and thus must be entirely dependent on nuclear-encoded proteins. This article reviews the evidence for the organelle in Cryptosporidium and its probable function.