Emerging New Phylogenetic Groups of Rabies Virus in Chinese Ferret Badgers

Chinese ferret badger（FB）-transmitted rabies is a serious threat to public health in southeast China. Although mostly associated with dogs, the rabies virus（RABV） presents genetic diversity and has a significantly wide host range in China. Instead of the dog-and wildlife-associated China ⅠI lineage in the past decades, the China Ⅰ lineage has become the main epidemic group hosted and transmitted by dogs. In this study, four new lineages, including 43 RABVs from FBs, have been classified within the dog-dominated China Ⅰ lineage since 2014. FBRABVs have been previously categorized in the China Ⅱ lineage. Moreover, FB-hosted viruses seem to have become the main independent FB-associated clade in the phylogenetic tree. This claim suggests that the increasing genetic diversity of RABVs in FBs is a result of the selective pressure from coexisting dog rabies. FB transmission has become complicated and serious with the coexistence of dog rabies. Therefore, apart from targeting FB rabies, priority should be provided by the appropriate state agencies to perform mass immunization of dog against rabies.

Genomic characterization and antimicrobial susceptibility of bovine intrauterine Escherichia coli and its relationship with postpartum uterine infections

To investigate the roles of Escherichia coli in the pathogenesis of postpartum uterine diseases in dairy cows, a total of 145 E. coli isolates were recovered from 18 healthy cows （61 isolates） and 25 cows with clinical endometritis （84 isolates） at 25-35 days after parturition. Genomic characteristics including phylogenetic grouping, genetic diversity and virulence genes of E. coli isolates were screened to profile the characteristics related to uterine infections. The susceptibility of the bacteria against 23 antibiotics was also evaluated to support prevention and treatment of clinical cases. Genetic diversity of E. coli identified by random amplification of polymorphic DNA （RAPD） revealed 103 clonal types, including 3 common types to unaffected cows and endometritis cows, 39 types specific to healthy cows and 61 types in endometritis subjects. In addition, the isolates from endometritis uteri showed more genetic variability compared with that of healthy cows. Ac- cording to the findings of phylogenetic grouping, the E. coil isolates were assigned to group A （35.9%）, B1 （59.3%） and D （4.8%）. The expression of 10 of 20 virulence gens were detected positively, and only fimH gene was revealed significantly （P〈0.05） associated with endometritis. From antimicrobial susceptibility test, E. coli was found highly resistant to tetracy- cline, ampicillin, carbenicillin and amoxicillin, but sensitive to amikacin, netilmicin, tobramycin, cefepime and ceftazidime. In conclusion, E. cofiwere extensively observed in both healthy and endometritis cows, and presented a large clonal types, however, fimH was the only gene observed associated with clinical endometritis. Our results suggest that the drugs like amikacin, netilmicin, tobramycin and cefepime could be considered for preventing and treating clinical endometritis in the practical management of dairy cow.

Exotic Plant Alnus trabeculosa Alters the Composition and Diversity of Native Rhizosphere Bacterial Communities of Phragmites australis

Alnus trabeeulosa, a rhizobia-nodulating tree, was introduced into the Chongxi tidal wetland in the Yangtze River estuary of China to increase the biodiversity of plants and restore tidal wetland functions. However, the effect of the introduced plant on soil bacterial communities and restoration outcomes remains unknown. In this study, the rhizosphere bacterial community structure and diversity were compared between Phragrnites australis monospecific community and A. trabeculosa-P, australis mixed communities, aiming to assess whether A. trabeculosa influenced the rhizosphere bacterial communities of P. australis and to investigate whether different taxonomic groups within a soil community may respond similarly to the presence of an introduced exotic plant. Among the 14 phylogenetic phyla detected, Proteobacteria and Acidobacteria were the dominant bacterial taxa in the rhizosphere. Phylogenetic analysis of the predominant Proteobacteria showed that the clones from the rhizosphere soils of A. trabeculosa and P. australis in A. trabeculosa-P, australis mixed communities were more diverse than those in the rhizosphere soil of P. australis in P. australis monospecific community. The rhizosphere community in the wetland potentially included active microbial community related to carbon, nitrogen, and sulfur cycling in the Yangtze River estuary. The rhizosphere soil of P. australis in A. trabeculosa-P, australis mixed communities exhibited the highest Shannon diversity index （Hr） and Simpson diversity index （l/D） （H = 4.52, 1/D = 253）. Correspondence analyses revealed that the bacterial community structures were altered after A. trabeculosa was introduced.