Search

The widespread presence of carbapenem-resistant Enterobacteriaceae (CRE) and mcr -positive Escherichia coli (MCREC) poses a huge threat to both animal and human health. River water environments are vital reservoirs of antibiotic resistance genes, however, the prevalence and characteristics of CRE and MCREC from large-scale rivers in China have not been reported. In the current study, we sampled 86 rivers from four cities in Shandong Province, China in 2021 and analyzed the prevalence of CRE and MCREC. The bla NDM / bla KPC-2 / mcr -positive isolates were characterized with methods including PCR, antimicrobial susceptibility testing, conjugation, replicon typing, whole-genome sequencing and phylogenetic analysis. We found that the prevalence of CRE and MCREC in 86 rivers was 16.3% (14/86) and 27.9% (24/86), respectively and eight rivers carried both mcr-1 and bla NDM / bla KPC-2. A total of 48 Enterobacteriaceae isolates (10 ST11 Klebsiella pneumoniae with bla KPC-2 , 12 bla NDM -positive E. coli and 26 MCREC carrying only mcr-1) were obtained in this study and 47 displayed multidrug resistance (MDR). Notably, 10 of the 12 bla NDM -positive E. coli isolates also harbored the mcr-1 gene. The bla KPC-2 gene was located within mobile element IS Kpn27 - bla KPC-2 -IS Kpn6 on novel F33:A-:B- non-conjugative MDR plasmids in ST11 K. pneumoniae. The dissemination of bla NDM was mediated by transferable MDR IncB/O plasmids or IncX3 plasmids while mcr-1 was primarily disseminated by highly similar IncI2 plasmids. Notably, these waterborne IncB/O, IncX3 and IncI2 plasmids were all highly similar to previously identified plasmids from animal and human isolates. A phylogenomic analysis revealed that the CRE and MCREC isolates from water environments might be derived from animals and trigger infections in humans. The high prevalence of CRE and MCREC in large-scale environmental rivers is alarming and needs sustained surveillance due to the potential risk for transmission to humans via the food chain (irrigation) or direct contact. [Display omitted] • Carbapenem-resistant Enterobacteriaceae (CRE) and mcr -positive E. coli (MCREC) prevalence was 16.3% and 27.9%. • Up to 83.3% of the bla NDM -positive CRE isolates also carried mcr-1. • Bla NDM / mcr-1 -positive plasmids were highly similar to those from animals and humans. • CRE and MCREC from river water showed a potential in connecting animals and humans. [ABSTRACT FROM AUTHOR]

• We found that 6.6% (13/197) bats from Shandong and Hubei provinces of China carried hepatis B virus (HBVs). • HBVs from bats in the two places were phylogenetically in the same cluster, but distinct from bat HBVs from other places. • HBVs were highly prevalent and genetic diversified in bats, supporting the hypothesis that bats may be the origin of primate hepadnaviruses. Bats have been identified as the hosts of hepatitis B virus (HBV) in recent years and bats HBV can infect human hepatocyte. We investigated the prevalence and genetic diversity of HBV in bats in China. In this study, a total of 197 insectivorous bats belonging to 10 bat species were captured from karst caves in Mengyin County, Shandong Province and Xianning City, Hubei Province, China. PCR amplification indicated that in total 6.6% (13/197) bats were positive to HBVs. The HBV positive rate in bats was 7.1% (9/127) and 5.7% (4/70) in Shandong Province and Hubei Province, respectively. Phylogenetic analysis indicated that HBV from the two places were in the same cluster with 90.5%–99.5% homology, but distinct from bat HBVs from other places in China and other countries. We concluded that HBV was prevalent and genetic diversified in bats, supporting the hypothesis that bats may be the origin of primate hepadnaviruses. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome (PRRS), caused by the PRRS virus (PRRSV), is a significant threat to the global pig industry. In this study, a novel recombinant PRRSV, SD043, was isolated from a pig farm experiencing disease in 2019. Phylogenetic analysis revealed that SD043 belonged to lineage 1 of PRRSV-2 while recombination analyses revealed that it is a recombinant virus from lineage 1 and lineage 8 strains. Based on further analysis, SD043 underwent recombination twice. Pathogenicity studies revealed that SD043 causes mild clinical symptoms, thymus atrophy, and severe histopathological lesions in the lungs. Notably, virus shedding in SD043-infected piglets was detectable at 10 days post-inoculation with a high viral load in the respiratory or digestive tract, indicating that the recombinant PRRSV appears to shed higher numbers of virus. Furthermore, genomic surveillance based on all available PRRSVs circulating in Shandong province revealed an increasing increase in recombinant PRRSV since 2015, with the recombinant pattern (between lineages 1 and 8) being the same as that of SD043. These findings enable a better understanding of the process of twice recombination and virus shedding of recombinant PRRSV and can strengthen the prevention and control of the PRRSV epidemic. • The isolated recombinant PRRSV SD043 underwent twice inter-lineage recombination. • Virus shedding in SD043-infected piglets with a high viral load through respiratory or digestive tract. • Recombinant PRRSVs has increased in Shandong province since 2015, the recombinant pattern between L1 and L8. [ABSTRACT FROM AUTHOR]