Xiaoyi Dai

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 bla_KPC-2 and two bla_NDM-1. It also contained a plasmid-borne efflux pump gene cluster, tmexCD1-toprJ, conferring resistance to tigecycline. Analysis of plasmid sequences revealed that both bla_NDM-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 bla_NDM-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.

The present study is aimed at investigating the association of NFE2L2 gene polymorphisms with risk and clinical characteristics of acute type A aortic dissection (AAAD) in a Han Chinese population. Six SNPs (rs1806649, rs13001694, rs2364723, rs35652124, rs6721961, and rs2706110) in NFE2L2 were genotyped using SNaPshot Multiplex Kit in 94 adult patients diagnosed with AAAD at our hospital, and 208 healthy Han Chinese subjects from the 1000 Genomes Project were served as the control group. The CC genotype of rs2364723 (CC versus (GC+GG), OR = 2.069, 95% CI: 1.222‐3.502, p = 0.006) and CC genotype of rs35652124 (CC versus (CT+TT), OR = 1.889, 95% CI: 1.112‐3.210, p = 0.018) were identified as risk factors for AAAD. Multivariable linear regression analysis revealed that the CC genotype of rs2364723 (β = 5.031, 95% CI: 1.878‐8.183, p = 0.002) and CC genotype of rs35652124 (β = 4.751, 95% CI: 1.544‐7.958, p = 0.004) were associated with increased maximum ascending aorta diameter of AAAD. Patients carrying rs2364723 CC genotype had a higher incidence of coronary artery involvement (31% vs. 12%, p = 0.027), while patients carrying rs35652124 CC genotype had a higher incidence of brain ischemia (9% vs. 0%, p = 0.045). In conclusion, NFE2L2 gene polymorphisms were correlated with risk and severity of AAAD in Han Chinese population.