AUTHOR=Wang Jing , Wang Yan , Wu Han , Wang Zhen-Yu , Shen Peng-Cheng , Tian Yu-Qi , Sun Fan , Pan Zhi-Ming , Jiao Xinan 

TITLE=Coexistence of blaOXA-58 and tet(X) on a Novel Plasmid in Acinetobacter sp. From Pig in Shanghai, China

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.578020

DOI=10.3389/fmicb.2020.578020

ISSN=1664-302X

ABSTRACT=<p>The purpose of this study was to characterize the complete sequence of a novel plasmid carrying tigecycline resistance gene <italic>tet</italic>(X) and carbapenemase gene <italic>bla</italic><sub>OXA-58</sub> from a swine <italic>Acinetobacter</italic> sp. strain SH19PTT10. Minimal inhibitory concentration (MIC) was performed using microbroth dilution method. The isolate SH19PTT10 was highly resistant (16 mg/L) to tigecycline, and also exhibited resistance to ampicillin, streptomycin, tetracycline, chloramphenicol, florfenicol, ciprofloxacin, and sulfamethoxazole/trimethoprim. Although SH19PTT10 harbored <italic>bla</italic><sub>OXA-58</sub>, it was susceptible to cefotaxime and meropenem. The genome sequence of SH19PTT10 was determined using PacBio single-molecule real-time sequencing. Plasmid pYUSHP10-1 had a size of 174,032 bp and showed partial homology to several plasmids found in <italic>Acinetobacter</italic> isolates. It contained two <italic>repA</italic> genes, putative toxin-antitoxin systems (HipA/HipB, RelE/RelB, and BrnT/BrnA), partitioning genes (<italic>parA</italic> and <italic>parB</italic>), and heavy metal resistance-associated genes (<italic>copA</italic>/<italic>copB</italic>, <italic>nrp</italic>, and <italic>czcA</italic>/<italic>czcD</italic>) but the transfer region or proteins was not found. pYUSHP10-1 carried 16 resistance genes, mainly clustered in two mosaic multiresistance regions (MRRs). The first MRR contained <italic>sul3</italic>, <italic>qacI</italic>-<italic>aadA1</italic>-<italic>clmA1</italic>-<italic>aadA2</italic>-<italic>bla</italic>CARB-2-<italic>dfrA16</italic> cassette, <italic>aac(3)</italic>-<italic>IId</italic>, and <italic>bla</italic><sub>OXA-58</sub>. The <italic>bla</italic><sub>OXA-58</sub> gene was associated with IS<italic>Aba3</italic>, as previously described. The second MRR is the <italic>tet</italic>(X) region (IS<italic>Acsp12</italic>-<italic>aph(3')</italic>-<italic>Ia</italic>-IS<italic>26</italic>-Δ<italic>xerD</italic>-<italic>tet</italic>(X)-<italic>res</italic>-IS<italic>CR2</italic>-<italic>sul2</italic>) related to the corresponding region in other <italic>tet</italic>(X)-bearing plasmids. The p<italic>dif</italic> sites, as well as mobile elements, play an important role in mobilization of DNA modules and plasmid evolution. Coexistence of numerous resistance genes on a single plasmid may contribute to the dissemination of these genes under pressure posed by different agents, which may explain the presence of clinically crucial resistance genes <italic>tet</italic>(X) and <italic>bla</italic><sub>OXA-58</sub> in livestock. Thus, rational drug use and continued surveillance of <italic>tet</italic>(X) and <italic>bla</italic><sub>OXA-58</sub> in livestock are warranted.</p>