Grooters Susan Vaughn, Mollenkopf Dixie F, Wittum Thomas E
Department of Veterinary Preventive Medicine, The Ohio State University, Coumbus, Ohio, United States of America.
PLoS One. 2025 Jul 23;20(7):e0327200. doi: 10.1371/journal.pone.0327200. eCollection 2025.
The blaIMP resistance gene encodes a metallo-beta-lactamase in bacteria, which confers reduced susceptibility or resistance to all the beta-lactams, including carbapenems which are critical for treating life-threatening infections. The dissemination of blaIMP among various taxonomic families shows the diversity and range of horizontal gene transfer. Using short-read whole genome sequencing and bioinformatic tools, we determined the genetic motifs surrounding blaIMP present in 32 bacterial isolates recovered from environmental sources and agriculture facilities. blaIMP can be located extra-chromosomally on plasmids or within incomplete and complete Tn7 chromosomal structures. We identified a complete Tn7 transposon harboring the blaIMP-27 gene cassette within a class 2 integron located in chromosomal contigs of Shewanella spp. and Providencia spp. Acinetobacter spp. isolates were observed with truncated and incomplete Tn7 transposons, while conserving the class 2 integron and resistance gene cassettes. Additionally, IncQ1 plasmids carried by Proteus spp., Escherichia coli, and other Enterobacteriaceae spp. harbored class 2 integrons with blaIMP-64 and sat2 resistance gene cassettes. In an Acidovorax sp. isolate, blaIMP-27 and sat2 gene cassettes were found associated with an insertion sequence, ISL3 transposase, in an RP4 plasmid. The conserved structure of Tn7 in Shewanella spp. and Providencia spp. is consistent with these species being potential reservoirs from which other bacterial species have acquired partial Tn7 motifs, and the blaIMP-27 gene cassette. These data contribute to a broader understanding of the dissemination and temporality of blaIMP alleles and their mobile genetic elements.
blaIMP耐药基因在细菌中编码一种金属β-内酰胺酶，该酶会降低细菌对所有β-内酰胺类药物的敏感性或使其产生耐药性，包括对治疗危及生命的感染至关重要的碳青霉烯类药物。blaIMP在不同分类科中的传播显示了水平基因转移的多样性和范围。我们使用短读长全基因组测序和生物信息学工具，确定了从环境源和农业设施中分离出的32株细菌中blaIMP周围的遗传基序。blaIMP可位于质粒的染色体外，或存在于不完整和完整的Tn7染色体结构内。我们在希瓦氏菌属和普罗威登斯菌属染色体重叠群中的2类整合子内，鉴定出一个携带blaIMP-27基因盒的完整Tn7转座子。在不动杆菌属分离株中观察到截短和不完整的Tn7转座子，同时保留了2类整合子和耐药基因盒。此外，变形杆菌属、大肠杆菌和其他肠杆菌科细菌携带的IncQ1质粒含有带有blaIMP-64和sat2耐药基因盒的2类整合子。在一株嗜酸菌属分离株中，发现blaIMP-27和sat2基因盒与RP4质粒中的插入序列ISL3转座酶相关。希瓦氏菌属和普罗威登斯菌属中Tn7的保守结构表明，这些物种可能是其他细菌物种获取部分Tn7基序和blaIMP-27基因盒的潜在储存库。这些数据有助于更广泛地了解blaIMP等位基因及其移动遗传元件的传播和时间性。
