A new double digestion ligation mediated suppression PCR method for simultaneous bacteria DNA-typing and confirmation of species: an Acinetobacter sp. model

Whole-genome sequencing-based analysis of antimicrobial resistance, virulence factors, and genetic diversity in Yersinia isolated in Wenzhou, China 2020

Yersinia spp. vary significantly in their ability to cause diseases that threaten public health. Their pathogenicity is frequently associated with increasing antimicrobial resistance (AMR) and various virulence factors. The aim of the study was to investigate the AMR genes, virulence factors, and genetic diversity of Yersinia strains isolated from meats and fish in Wenzhou in 2020 by using whole-genome sequencing (WGS). A total of 50 isolates were collected. The phylogenetic relationships among the Yersinia species were also analyzed using multilocus sequence typing (MLST), core genome multi-locus sequence typing (cgMLST), and single nucleotide polymorphism (SNP) analysis. According to the results, all the strains could be classified into five species, with most isolated from beef, followed by poultry, pork, and fish. AMR genes were identified in 23 strains. And the qnrD1 genes were all located in the Col3M plasmid. Virulence genes, such as yaxA, ystB, pla, and yplA, were also found in the 15 Y. enterocolitica strains. And this study also found the presence of icm/dot type IVB-related genes in one Yersinia massiliensis isolate. MLST analysis identified 43 sequence types (STs), 19 of which were newly detected in Yersinia. Moreover, cgMLST analysis revealed that no dense genotype clusters were formed (cgMLST 5341, 5344, 5346-5350, 5353-5390). Instead, the strains appeared to be dispersed over large distances, except when multiple isolates shared the same ST. Isolates Y4 and Y26 were closely related to strains originating from South Korea and Denmark. This study showed considerable diversity in Yersinia spp. isolated from local areas (Wenzhou City). The data generated in our study may enrich the molecular traceability database of Yersinia and provide a basis for the development of more effective antipathogen control strategies.

Update on the epidemiological typing methods for Acinetobacter baumannii

The outstanding ability of Acinetobacter baumannii to cause outbreaks and acquire multidrug resistance motivated the development of a plethora of typing techniques, which can help infection preventionists and hospital epidemiologists to more efficiently implement intervention controls. Nowadays, the world is witnessing a gradual transition from traditional typing methodology to whole genome sequencing-based approaches. Such approaches are opening new prospects and applications never achieved by existing typing methods. Herein, we provide the reader with an updated review on A. baumannii typing methods recapping the added value of well-established techniques previously applied for A. baumannii and detailing new ones (as clustered regularly interspaced short palindromic repeats-based typing) with a special focus on whole genome sequencing.