Department of Bacteriology-Parasitology-Hygiene, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France.
Associated French National Reference Center for Antibiotic Resistance, Le Kremlin-Bicêtre, France.
Antimicrob Agents Chemother. 2017 Dec 21;62(1). doi: 10.1128/AAC.01879-17. Print 2018 Jan.
spp. constitute a reservoir of antibiotic resistance determinants. In a bile sample, we identified three extended-spectrum-β-lactamase (ESBL)-producing bacteria (, , and sp. strain JAB-1) isolated from a child suffering from cholangitis. Our objectives were to characterize the genome and the resistome of the first ESBL-producing isolate of the genus and determine whether plasmidic exchange occurred between the three bacterial species. Bacterial isolates were characterized using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), standard biochemical tools, and antimicrobial susceptibility testing. sp. JAB-1 and ESBL gene-encoding plasmids were characterized using PacBio and Illumina whole-genome sequencing, respectively. The sp. JAB-1 chromosome-encoded OXA-48 variant was cloned and functionally characterized. Whole-genome sequencing (WGS) of the sp. clinical isolate JAB-1 revealed the presence of a 193-kb plasmid belonging to the IncA/C incompatibility group and harboring two ESBL genes, and gene-carrying plasmids belonging to the IncY and IncR incompatibility groups were also found in the and isolates from the same patient, respectively. A comparison of the genetic environment indicated the independent origin of these plasmids and dismissed transfers. Furthermore, characterization of the resistome of sp. JAB-1 revealed the presence of a chromosome-carried gene, likely the progenitor of the plasmid-carried gene, a novel -like gene. The expression of in showed the carbapenem-hydrolyzing activity of OXA-535. The production of OXA-535 in sp. JAB-1 could be evidenced using molecular and immunoenzymatic tests, but not with biochemical tests that monitor carbapenem hydrolysis. In this study, we have identified a CTX-M-15-producing species that was responsible for a hepatobiliary infection and that is likely the progenitor of OXA-436, a novel plasmid-encoded OXA-48-like class D carbapenemase.
种构成了抗生素耐药决定因素的储库。在一份胆汁样本中，我们从一名患有胆管炎的儿童中分离出三种产超广谱β-内酰胺酶（ESBL）的细菌（，和 sp. 菌株 JAB-1）。我们的目标是表征种的第一株产 ESBL 细菌的基因组和耐药组，并确定这三种细菌之间是否发生了质粒交换。使用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）、标准生化工具和抗菌药物敏感性测试对细菌分离株进行了表征。使用 PacBio 和 Illumina 全基因组测序分别对 sp. JAB-1 中的 ESBL 基因编码质粒进行了表征。克隆和功能表征了 sp. JAB-1 染色体编码的 OXA-48 变体。对 sp. 临床分离株 JAB-1 的全基因组测序（WGS）显示，存在一个 193-kb 质粒，属于 IncA/C 不相容群，携带两个 ESBL 基因，和 基因。在来自同一患者的 和 分离株中也发现了携带 IncY 和 IncR 不相容群的 基因的质粒。对 基因环境的比较表明这些质粒具有独立的起源，并排除了 基因的转移。此外，对 sp. JAB-1 耐药组的表征表明，存在一个染色体携带的 基因，可能是质粒携带的 基因的前体，这是一种新型的 -样基因。在 中表达 显示了 OXA-535 对碳青霉烯类的水解活性。在 sp. JAB-1 中可以通过分子和免疫酶试验检测到 OXA-535 的产生，但不能通过监测碳青霉烯类水解的生化试验检测到。在这项研究中，我们鉴定了一种产 CTX-M-15 的 种，该种引起了肝胆感染，并且可能是新型质粒编码的 OXA-48 样类 D 碳青霉烯酶 OXA-436 的前体。
