Aflatoxin B1 causes oxidative stress and apoptosis in sheep testes associated with disrupting rumen microbiota.

Aflatoxin B1 (AFB1) is an unavoidable environmental pollutant commonly found in feed and foodstuffs. It is the most toxic one of all the aflatoxins, which can cause severe impairment to testicular development and function. Yet, the underlying mechanisms of reproductive toxicity in rams sheep remain inconclusive. The study was designed to explore the effects of AFB1 on sheep testes through rumen-microbiota, oxidative stress and apoptosis. Six-month-old male Dorper rams (n = 6) were orally administrated with 1.0 mg/kg AFB1 (dissolved in 20 mL 4% ethanol) 24 h before the experiment. At the same time, rams in the control group (n = 6) were intragastrically administrated with 20 mL 4% ethanol. It was observed that acute AFB1 poisoning had significant (p < 0.05) toxin residue in the testis and could cause testicular histopathological damage. AFB1 stimulated the secretion of plasma testosterone level through regulating testosterone synthesis-related genes (StAR, 3ß-HSD, CYP11A1, and CYP17A1), which are accompanied by the increase of oxidative stress and testicular apoptosis that had a close relationship with the regulation of testosterone secretion. Interestingly, we observed rumen dysbacteriosis and decreased the abundances of Prevotella, Succiniclasticum, CF231, Ruminococcus, and Pseudobutyrivibrio in AFB1-exposed sheep, which were negatively correlated to the testosterone synthesis-related gene levels. Taken together, our findings indicated that AFB1 induced testicular damage and testicular dysfunction, which is related to testicular oxidative stress and apoptosis involved in rumen dysbacteriosis in sheep.

Aflatoxin B1 alters meat quality associated with oxidative stress, inflammation, and gut-microbiota in sheep.

Aflatoxin B1 (AFB1) is an unavoidable contaminant in animal feed and agricultural products. AFB1 has been found to impair the liver and kidney function of sheep. However, few data are available, which explain the toxic damage of AFB1 exposure on meat quality. In the study, male Dorper RAMS sheep (6-month-old) were orally administrated with AFB1 at the dose of 1 mg/kg body weight once. The body temperature, serum biochemistry, meat quality-related parameters, oxidation indicators in meat and serum, the mRNA expression of pro-inflammatory cytokines and anti-inflammatory, and microbiota composition of feces were measured 24 h after AFB1 exposure. The results showed that the body temperature was slightly increased, the mental state of mutton sheep was suppressed, and biochemical indicators were significantly changed after AFB1 exposure. AFB1 impaired mutton quality reflected by the structure of muscle fibers was changed, and increased muscle drip loss and lightness (L*), and decreased muscle redness (a*). Moreover, we found that AFB1 caused changes in the oxidative stress indicators T-SOD, T-AOC, MDA, GSH level, and GSH/GSSG ratio, and inflammation damage of mutton reflected by increasing pro-inflammatory TNF-α and reducing anti-inflammatory IL-10 mRNA levels, disrupts the secretion of inflammatory factors, and changed the composition of gut microbiota reflected by significantly increased Firmicutes/Bacteroidetes ratio and decreased the abundances of Butyrivibrio, which are related to the quality of the mutton. In summary, gut microbiota participates in AFB1 to damage mutton quality, which may be co-mediated by oxidative stress, inflammation, and gut microbiota.

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.

[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.