AUTHOR=Fu Jiafang , Zhong Chuanqing , Zhang Peipei , Gao Qingxia , Zong Gongli , Zhou Yingping , Cao Guangxiang 

TITLE=A Novel Mobile Element ICERspD18B in Rheinheimera sp. D18 Contributes to Antibiotic and Arsenic Resistance

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.616364

DOI=10.3389/fmicb.2020.616364

ISSN=1664-302X

ABSTRACT=<p>Antibiotics and organoarsenical compounds are frequently used as feed additives in many countries. However, these compounds can cause serious antibiotic and arsenic (As) pollution in the environment, and the spread of antibiotic and As resistance genes from the environment. In this report, we characterized the 28.5 kb genomic island (GI), named as ICE<italic>Rsp</italic>D18B, as a novel chromosomal integrative and conjugative element (ICE) in multidrug-resistant <italic>Rheinheimera</italic> sp. D18. Notably, ICE<italic>Rsp</italic>D18B contains six antibiotic resistance genes (ARGs) and an arsenic tolerance operon, as well as genes encoding conjugative transfer proteins of a type IV secretion system, relaxase, site-specific integrase, and DNA replication or partitioning proteins. The transconjugant strain 25D18-B4 was generated using <italic>Escherichia coli</italic> 25DN as the recipient strain. ICE<italic>Rsp</italic>D18B was inserted into 3'-end of the <italic>guaA</italic> gene in 25D18-B4. In addition, 25D18-B4 had markedly higher minimum inhibitory concentrations for arsenic compounds and antibiotics when compared to the parental <italic>E. coli</italic> strain. These findings demonstrated that the integrative and conjugative element ICE<italic>Rsp</italic>D18B could mediate both antibiotic and arsenic resistance in <italic>Rheinheimera</italic> sp. D18 and the transconjugant 25D18-B4.</p>