摘要
      植物拉乌尔氏菌是一种新出现的病原体，可导致人类多种感染，其在抗生素耐药性基因（ARGs）传播中的作用尚不明确。在这项研究中，从医院污水中回收了一种耐碳青霉烯和替加环素的植物分枝杆菌分离物。它携带9个质粒，携带30个ARGs，包括一个blaKPC-2和两个blaNDM-1。它还含有一个质粒携带的外排泵基因簇tmexCD1-toprJ，赋予对替加环素的耐药性。对质粒序列的分析表明，两种blaNDM-1编码质粒与从人类中回收的质粒高度相似，这加强了环境和临床分离株的密切相关性。我们还鉴定了携带blaNDM-1或tmexCD1-to-prJ1的质粒是可转移的，并且可以在宿主细菌中稳定，这表明R.planticola分离物在ARGs的传播中具有相当大的潜力。此外，我们发现这种分离物可以产生生物膜，并且在意大利黑加仑菌感染模型中具有毒性。总之，我们的研究表明，在一个R.planticola分离株中，毒力和多药耐药性是一致的。这种具有潜在毒性的超级细菌可能会传播到其接收河流，并最终通过娱乐活动或日常用水过程中的交叉污染传播给人类，这对公众健康构成了风险。
Abstract
Raoultella planticola is an emerging pathogen causing several infections in humans, and its roles in the propagation of antibiotic resistance genes (ARGs) remain uncharacterized. In this study, a carbapenem and tigecycline-resistant R. planticola isolate was recovered from hospital sewage. It carried nine plasmids, bearing 30 ARGs, including one blaKPC-2 and two blaNDM-1. It also contained a plasmid-borne efflux pump gene cluster, tmexCD1-toprJ, conferring resistance to tigecycline. Analysis of plasmid sequences revealed that both blaNDM-1-carrying plasmids were highly similar to those recovered from humans, reinforcing the close relatedness of environmental and clinical isolates. We also identified that plasmid bearing blaNDM-1 or tmexCD1-toprJ1 was transferable, and can be stabilized in the host bacteria, indicating that the R. planticola isolate has a considerable potential in the dissemination of ARGs. Besides, we found that this isolate could produce biofilm and was virulent in a Galleria mellonella infection model. In conclusion, our study shows the convergence of virulence and multidrug resistance in a R. planticola isolate. This potentially virulent superbug may disseminate into its receiving rivers, and finally to humans through cross-contamination during recreation activities or daily use of water, which poses a risk to public health.

https://www.nature.com/articles/s41598-022-07778-0