High prevalence of extrapulmonary tuberculosis in dairy farms: Evidence for possible gastrointestinal transmission.

Bovine tuberculosis (bTB) caused by Mycobacterium bovis (M. bovis) represents one of major zoonotic diseases among cattle, it also affects the health of human, other domestic animals and wild life populations. Inhalation of infected aerosol droplets is considered as the most frequent route of the infection. This study aims to investigate the current forms of tuberculosis in cattle and identify the possible transmission modes in dairy farms of China. 13,345 cows from eight dairy farms in three provinces were comprehensively diagnosed by a multitude of assays, including SIT, CIT, IFN-γ assay and ELISA. It has been indicated that advanced infection of bTB was found in 752 (5.64%) cattle, suggesting a high prevalence of tuberculosis in these dairy farms. In the necropsy examination of 151 positive cattle, typical bTB lesions were observed in 131 cattle (86.75%), of which, notably, 90.84% lesions appeared in liver, spleen, mesenteric lymph nodes, mammary lymph nodes and other organs, taking up a large proportion among cattle with advanced bTB infection. 71.26% extrapulmonary tuberculosis (EPTB) was related to gastrointestinal system. M. bovis nucleic acid was further found in milk and feces samples and M. bovis was even isolated from milk samples. Phylogenetic analysis based on whole genome sequencing unraveled that six isolates were closely related to M. bovis AF2122/97 originated from UK, whereas four isolates shared close relation to M. bovis 30 from China, respectively. Our data demonstrate that the increase of EPTB transmitted by digestive tract is implicated in the current high prevalence rate of bTB in China, which also provides leads for bTB control in other countries with high prevalence of bTB in the future.

Genome sequence analysis reveals potential for virulence genes and multi-drug resistance in an Enterococcus faecalis 2A (XJ05) strain that causes lamb encephalitis.

BACKGROUND: Enterococcus is an important component of normal flora in human and animals, but in recent years, the pathogenicity of Enterococcus has been confirmed in clinical medicine. More and more animal infections have been reported in veterinary clinics. For the last decades, outbreaks of encephalitis in lambs have become much more common in Northern Xinjiang, China. Consequent studies have confirmed that these affected lambs had been commonly infected with E. faecalis. More than 60 E. faecalis were isolated from the brain of infected lambs, A highly virulent strain entitled E. faecalis 2A (XJ05) were selected, sequenced and analyzed. RESULT: Using whole genome sequence and de novo assembly, 18 contigs with NGS and annotation were obtained. It is confirmed that the genome has a size of 2.9 Mb containing 2783 protein-coding genes, as well as 54 tRNA genes and 4 rRNA genes. Some key features of this strain were identified, which included 7 predicted antibiotic resistance genes and 18 candidate virulence factor genes. CONCLUSION: The E. faecalis 2A (XJ05) genome is conspicuous smaller than E.faecalis V583, but not significantly different from other non-pathogenic E. faecalis. It carried 7 resistance genes including 4 kind of antibiotics which were consistent with the results of extensive drug resistance phenotypic, including aminoglycoside, macrolide, phenicol, and tetracycline. 2A (XJ05) also carried 18 new virulence factor genes related to virulence, hemolysin genes (cylA, cylB, cylM, cylL) may play an important role in lamb encephalitis by E. faecalis 2A (XJ05).

Deletion of the Type IV Secretion System Effector VceA Promotes Autophagy and Inhibits Apoptosis in Brucella-Infected Human Trophoblast Cells.

Brucellosis is the most common zoonotic disease that caused by intracellular parasitic bacteria Brucella. The survival and replication of Brucella in the host depend on the type IV secretion system (T4SS). The T4SS system of Brucella has many components and secreted proteins. But the mechanism helped Brucella to evade the host defense is still not clear. The objective of the present study was to investigate the effects of VceA on autophagy and apoptosis in Brucella-infected embryonic trophoblast cells. We constructed the VceA mutant strain (2308ΔVceA) and complementary strain (2308ΔVceA-C) of Brucella abortus 2308 (S2308). The human trophoblast cells (HPT-8 cells) and mice were infected by S2308, 2308ΔVceA and 2308ΔVceA-C. The cell autophagy and apoptosis were detected. The Atg5, LC3-II and Bcl-2 mRNA expression were significantly increased in 2308ΔVceA group than the S2308 group, and mRNA expression of P62 and Caspase-3 were significantly decreased than the S2308 group. Western blotting, qPCR and flow cytometry analysis showed that 2308ΔVceA promoted autophagy and inhibited apoptosis. Mouse immunohistochemistry experiments showed that P62 protein was scattered coloring and Cytochrome C protein was scarcely in 2308ΔVceA group at the myometrium. These results indicated that 2308ΔVceA promoted autophagy and inhibited apoptosis in HPT-8 cells during Brucella infection.

Seroprevalence of Toxoplasma gondii in dogs in Shandong, Henan, and Heilongjiang Provinces, and in the Xinjiang Uygur Autonomous Region, People's Republic of China.

Seroprevalence of Toxoplasma gondii infection was determined in sera of 632 dogs (551 pets, 81 strays) from Shandong, Henan, and Heilongjiang Provinces, and in the Xinjiang Uygur Autonomous Region, People's Republic of China (PRC), using the indirect hemagglutination assay (cutoff titer 1:64 or higher); 11.1% were seropositive. The seroprevalence in stray dogs and in ≥3-yr-old dogs was significantly higher (P < 0.05) than that in household dogs and in <3-yr-old dogs. There were no significant differences in terms of gender, breed, or locality (P ≥ 0.05). The results indicate that T. gondii infections are common in dogs in PRC.