Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Microbiología, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Tecnológicas - CONICET, Buenos Aires, Argentina.
Hospital de Infecciosas "Dr. Francisco Javier Muñiz", Buenos Aires, Argentina.
Rev Argent Microbiol. 2020 Oct-Dec;52(4):298-304. doi: 10.1016/j.ram.2019.12.001. Epub 2020 Jan 23.
Metallo-β-lactamases (MBL) producing Pseudomonas aeruginosa isolates have been well characterized. Quinolones are commonly used in the treatment of carbapenem-resistant P. aeruginosa infections; however, data about PMQR in this species are scarce. The objective of this study was to report the simultaneous presence of qnrS and bla in P. aeruginosa, and to characterize the qnrS-harboring plasmid. Thirty-eight carbapenem-resistant P. aeruginosa isolates were recovered from a hospital in Buenos Aires during 2012. Screening for MBL was assessed by the double disk synergy test using EDTA and carbapenem discs. Plasmid DNA extraction was performed by a method using phenol-chloroform. PCR followed by sequencing was carried out to determine each MBL and PMQR allele. PCR-BseGI-RFLP was performed to detect aac-(6')-Ib-cr. The gyrA-QRDR was sequenced in those PMQR-harboring isolates. Plasmid incompatibility groups and addiction systems were characterized by PCR. The PMQR-carrying plasmid was sequenced using Illumina technology, annotated using RAST and manually curated. Eleven/38 isolates were VIM producers (bla and bla) while 1/38 harbored bla. One isolate harbored bla and the PMQR qnrS1; however, both markers were located in different plasmids. The qnrS1-harboring plasmid (pP6qnrS1) was 117945bp in size, presented 154 CDS and corresponded to the IncR group. In addition to qnrS1, it harbored several aminoglycoside resistance markers. Although pP6qnrS1 was non-conjugative, it presented an oriT which made it possible for this plasmid to be transferable. This is the first report on P. aeruginosa carrying both bla and qnrS1, plus the first detection of an IncR plasmid in Argentina.
产金属β-内酰胺酶（MBL）的铜绿假单胞菌分离株已有很好的特征描述。喹诺酮类药物常用于治疗碳青霉烯类耐药铜绿假单胞菌感染；然而，关于该物种中 PMQR 的数据很少。本研究的目的是报告同时存在 qnrS 和 bla 在铜绿假单胞菌中，并对携带 qnrS 的质粒进行特征描述。2012 年，从布宜诺斯艾利斯的一家医院中回收了 38 株碳青霉烯类耐药铜绿假单胞菌分离株。通过使用 EDTA 和碳青霉烯类药物的双碟协同试验评估 MBL 的筛选。使用酚-氯仿法进行质粒 DNA 提取。通过 PCR 测序确定每个 MBL 和 PMQR 等位基因。进行 PCR-BseGI-RFLP 以检测 aac-(6')-Ib-cr。在携带 PMQR 的分离株中对 gyrA-QRDR 进行测序。通过 PCR 对质粒不相容群和附加系统进行特征描述。使用 Illumina 技术对携带 PMQR 的质粒进行测序，使用 RAST 进行注释，并手动编辑。11/38 株为 VIM 生产者（bla 和 bla），而 1/38 株携带 bla。1 株携带 bla 和 PMQR qnrS1；然而，这两个标记都位于不同的质粒上。qnrS1 携带质粒（pP6qnrS1）大小为 117945bp，有 154 个 CDS，属于 IncR 组。除了 qnrS1，它还携带几个氨基糖苷类药物耐药标记。尽管 pP6qnrS1 是非接合性的，但它有一个 oriT，这使得该质粒能够转移。这是首次报道铜绿假单胞菌同时携带 bla 和 qnrS1，也是阿根廷首次检测到 IncR 质粒。
