AUTHOR=Li Jia , Li Yang , Cao Xiaoli , Zheng Jie , Zhang Yan , Xie Hui , Li Chuchu , Liu Chang , Shen Han 

TITLE=Genome-wide identification and oxacillinase OXA distribution characteristics of Acinetobacter spp. based on a global database

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1174200

DOI=10.3389/fmicb.2023.1174200

ISSN=1664-302X

ABSTRACT=<sec><title>Objective</title><p>To use genomic analysis to identify <italic>Acinetobacter</italic> spp. and to explore the distribution characteristics of ß-lactamase oxallicinases (<italic>bla</italic>OXA) among <italic>Acinetobacter</italic> species globally.</p></sec><sec><title>Methods</title><p>Genomes of global <italic>Acinetobacter</italic> spp. were downloaded from GenBank using Aspera batch. After quality check using CheckM and QUAST software, the genomes were annotated using Prokka software to investigate the distribution of <italic>bla</italic>OXAs across <italic>Acinetobacter</italic> spp.; a phylogenetic tree was constructed to explore the evolutionary relationship among the <italic>bla</italic>OXA genes in <italic>Acinetobacter</italic> spp. Average-nucleotide identification (ANI) was performed to re-type the <italic>Acinetobacter</italic> spp. BLASTN comparison analysis was implemented to determine the sequence type (ST) of <italic>Acinetobacter baumannii</italic> strain.</p></sec><sec><title>Results</title><p>A total of 7,853 genomes were downloaded, of which only 6,639 were left for further analysis after quality check. Among them, 282 <italic>bla</italic>OXA variants were identified from the genomes of 5,893 <italic>Acinetobacter</italic> spp.; <italic>bla</italic>OXA-23 (<italic>n</italic> = 3,168, 53.8%) and <italic>bla</italic>OXA-66 (2,630, 44.6%) were the most frequent <italic>bla</italic>OXAs, accounting for 52.6% (3,489/6639), and the co-carriage of <italic>bla</italic>OXA-23 and <italic>bla</italic>OXA-66 was seen in 2223 (37.7%) strains. The 282 <italic>bla</italic>OXA variants were divided into 27 clusters according to the phylogenetic tree. The biggest clade was <italic>bla</italic>OXA-51-family carbapenem-hydrolyzing enzymes composed of 108 <italic>bla</italic>OXA variants. Overall, 4,923 <italic>A</italic>. <italic>baumannii</italic> were identified out of the 6,639 <italic>Acinetobacter</italic> spp. strains and 291 distinct STs were identified among the 4,904 <italic>bla</italic>OXA-carrying <italic>A</italic>. <italic>baumannii</italic>. The most prevalent ST was ST2 (<italic>n</italic> = 3,023, 61.6%) followed by ST1 (<italic>n</italic> = 228, 4.6%).</p></sec><sec><title>Conclusion</title><p>OXA-like carbapenemases were the main <italic>bla</italic>OXA-type β-lactamase spread widely across <italic>Acinetobacter</italic> spp. Both <italic>bla</italic>OXA-23 and <italic>bla</italic>OXA-66 were the predominant <italic>bla</italic>OXAs, among all <italic>A</italic>. <italic>baumannii</italic> strains, with ST2 (belonging to CC2) being the main clone disseminated globally.</p></sec>