AUTHOR=Zhou Danying , Sun Zhewei , Lu Junwan , Liu Hongmao , Lu Wei , Lin Hailong , Zhang Xueya , Li Qiaoling , Zhou Wangxiao , Zhu Xinyi , Xu Haili , Lin Xi , Zhang Hailin , Xu Teng , Li Kewei , Bao Qiyu 

TITLE=Characterization of a Novel Chromosomal Class C β-Lactamase, YOC-1, and Comparative Genomics Analysis of a Multidrug Resistance Plasmid in Yokenella regensburgei W13

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.02021

DOI=10.3389/fmicb.2020.02021

ISSN=1664-302X

ABSTRACT=<p><italic>Yokenella regensburgei</italic>, a member of the family Enterobacteriaceae, is usually isolated from environmental samples and generally resistant to early generations of cephalosporins. To characterize the resistance mechanism of <italic>Y. regensburgei</italic> strain W13 isolated from the sewage of an animal farm, whole genome sequencing, comparative genomics analysis and molecular cloning were performed. The results showed that a novel chromosomally encoded class C β-lactamase gene with the ability to confer resistance to β-lactam antibiotics, designated <italic>bla</italic><sub><italic>YOC</italic></sub><sub>–</sub><sub>1</sub>, was identified in the genome of <italic>Y. regensburgei</italic> W13. Kinetic analysis revealed that the β-lactamase YOC-1 has a broad spectrum of substrates, including penicillins, cefazolin, cefoxitin and cefotaxime. The two functionally characterized β-lactamases with the highest amino acid identities to YOC-1 were CDA-1 (71.69%) and CMY-2 (70.65%). The genetic context of the <italic>bla</italic><sub><italic>YOC</italic></sub><sub>–</sub><sub>1</sub><italic>-ampR</italic>-encoding region was unique compared with the sequences in the NCBI nucleotide database. The plasmid pRYW13-125 of <italic>Y. regensburgei</italic> W13 harbored 11 resistance genes (<italic>bla</italic><sub><italic>OXA</italic></sub><sub>–</sub><sub>10</sub>, <italic>bla</italic><sub><italic>LAP</italic></sub><sub>–</sub><sub>2</sub>, <italic>dfrA14</italic>, <italic>tetA</italic>, <italic>tetR</italic>, <italic>cmlA5</italic>, <italic>floR</italic>, <italic>sul2</italic>, <italic>ant(3″)-IIa</italic>, <italic>arr-2</italic> and <italic>qnrS1</italic>) within an ∼34 kb multidrug resistance region; these genes were all related to mobile genetic elements. The multidrug resistance region of pYRW13-125 shared the highest identities with those of two plasmids from clinical <italic>Klebsiella pneumoniae</italic> isolates, indicating the possibility of horizontal transfer of these resistance genes between bacteria of various origins.</p>