AUTHOR=Sun Huarun , Zhang Junkai , Miao Qingqing , Zhai Yajun , Pan Yushan , Yuan Li , Yan Fengbin , Wu Hua , Hu Gongzheng 

TITLE=Genomic insight into the integrative conjugative elements from ICEHpa1 family

JOURNAL=Frontiers in Veterinary Science

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.986824

DOI=10.3389/fvets.2022.986824

ISSN=2297-1769

ABSTRACT=<p>Integrative conjugative elements (ICEs) are important carriers for disseminating resistance genes. We have previously reported a novel element ICE<italic>Hpa1</italic> carrying seven antibiotic resistance genes, which could be self-transmissible relying on the novel T4SS. To identify novel ICE<italic>Hpa1</italic> variants from 211 strains and novel T4SS encoded in ICE<italic>Hpa1</italic>, and to explore the relationships in these ICEs, four complete sequences of ICEs were identified by WGS analysis and antimicrobial susceptibility testing was determined by broth microdilution. In addition, a comparative analysis of these ICEs was conducted with bioinformatic tools, and the transfer abilities of these ICEs were confirmed by conjugation. Four ICE<italic>Hpa1</italic> variants ICE<italic>Gpa1818</italic>, ICE<italic>Gpa1808</italic>, ICE<italic>Gpa1807</italic>, and ICE<italic>Gpa1815</italic> with different resistance gene profiles were characterized, and their hosts showed different resistance spectrums. All ICEs shared the same backbone and were inserted into the tRNA<sup>Leu</sup> site, and all resistance regions were inserted into the same target site between the accessory and integration regions. This study analyzed complete sequences of ICEs from the ICE<italic>Hpa1</italic> family and identified novel T4SS and insertion element IS<italic>Gpa2</italic>. Diverse resistance genes extensively exist in these ICEs, serving as a reservoir for resistance genes and facilitating their dissemination.</p>