AUTHOR=Qian Changrui , Liu Hongmao , Cao Jiawei , Ji Yongan , Lu Wei , Lu Junwan , Li Aifang , Zhu Xinyi , Shen Kai , Xu Haili , Chen Qianqian , Zhou Wangxiao , Lu Hongyun , Lin Hailong , Zhang Xueya , Li Qiaoling , Lin Xi , Li Kewei , Xu Teng , Zhu Mei , Bao Qiyu , Zhang Hailin 

TITLE=Identification of floR Variants Associated With a Novel Tn4371-Like Integrative and Conjugative Element in Clinical Pseudomonas aeruginosa Isolates

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2021.685068

DOI=10.3389/fcimb.2021.685068

ISSN=2235-2988

ABSTRACT=<p>Florfenicol is widely used to control respiratory diseases and intestinal infections in food animals. However, there are increasing reports about florfenicol resistance of various clinical pathogens. <italic>floR</italic> is a key resistance gene that mediates resistance to florfenicol and could spread among different bacteria. Here, we investigated the prevalence of <italic>floR</italic> in 430 <italic>Pseudomonas aeruginosa</italic> isolates from human clinical samples and identified three types of <italic>floR</italic> genes (designated <italic>floR</italic>, <italic>floR-T1</italic> and <italic>floR-T2</italic>) in these isolates, with <italic>floR-T1</italic> the most prevalent (5.3%, 23/430). FloR-T2 was a novel <italic>floR</italic> variant identified in this study, and exhibited less identity with other FloR proteins than FloRv. Moreover, <italic>floR-T1</italic> and <italic>floR-T2</italic> identified in <italic>P. aeruginosa</italic> strain TL1285 were functionally active and located on multi-drug resistance region of a novel incomplete Tn<italic>4371</italic>-like integrative and conjugative elements (ICE) in the chromosome. The expression of the two <italic>floR</italic> variants could be induced by florfenicol or chloramphenicol. These results indicated that the two <italic>floR</italic> variants played an essential role in the host’s resistance to amphenicol and the spreading of these <italic>floR</italic> variants might be related with the Tn<italic>4371</italic> family ICE.</p>