1Laboratory Ward, National Bone Marrow Transplant Center, Tunis 1006, Tunisia.
2Faculty of Medicine of Tunis, Laboratory Ward, National Bone Marrow Transplant Center, University of Tunis El Manar, LR18ES39, 1006 Tunis, Tunisia.
Acta Microbiol Immunol Hung. 2023 Jul 25;70(3):199-205. doi: 10.1556/030.2023.02089. Print 2023 Sep 21.
Pseudomonas aeruginosa is one of the major infectious agents in burn patients. Globally, high rates of antimicrobial resistance in P. aeruginosa have been reported, which is a cause of concern. The objective of this study was to determine the rate of resistance to carbapenems in P. aeruginosa isolates recovered from burn patients in Tunisia, to search genes encoding for carbapenemases and to determine their epidemiological markers (serotypes). A retrospective study was conducted in the Burn Intensive Care Unit (BICU) of the Trauma and Burn Centre of Ben Arous, Tunisia, and P. aeruginosa isolates collected from burn patients, from January to December 2018 were investigated. Carbapenemase screening was performed by Carbapenem Inactivation Method (CIM) and by EDTA-disk test for all carbapenem resistant isolates. Genes encoding carbapenemases (blaVIM, blaIMP, blaGES, blaNDM, and blaKPC) were investigated by PCR and selected carbapenemase genes were sequenced. During the study period, 104 non duplicated P. aeruginosa isolates were recovered. Most of them were isolated from skin samples (45.1%) and blood culture (22.1%) and belonged to O:11 (19.2%), O:12, and O:5 (12.5%, each) serotypes. High rates of resistance were observed for carbapenems (64.4%). Among the 67 carbapenem resistant isolates, 58 (86.5%) harbored blaVIM gene and 55 (82%) blaGES gene; in addition, 48 (71.6%) co-harbored blaVIM and blaGES genes. After sequencing, the blaVIM-2 and blaGES-5 gene variants were identified in seven randomly selected isolates. To the best of our knowledge, this is the first description of P. aeruginosa simultaneously harboring blaVIM-2 and blaGES-5 genes.
铜绿假单胞菌是烧伤患者的主要感染病原体之一。在全球范围内，已报道铜绿假单胞菌对抗菌药物的耐药率很高，这令人担忧。本研究的目的是确定突尼斯烧伤患者分离的铜绿假单胞菌对碳青霉烯类药物的耐药率，寻找编码碳青霉烯酶的基因，并确定其流行病学标志物（血清型）。本研究是在突尼斯贝努阿鲁斯创伤和烧伤中心烧伤重症监护病房（BICU）进行的回顾性研究，调查了 2018 年 1 月至 12 月期间从烧伤患者中分离的铜绿假单胞菌。对所有耐碳青霉烯类药物的分离株进行碳青霉烯酶筛查，采用碳青霉烯失活法（CIM）和 EDTA 纸片试验。采用 PCR 法检测编码碳青霉烯酶的基因（blaVIM、blaIMP、blaGES、blaNDM 和 blaKPC），并对选定的碳青霉烯酶基因进行测序。在研究期间，共分离出 104 株非重复铜绿假单胞菌。它们大多来自皮肤样本（45.1%）和血培养（22.1%），血清型分别为 O:11（19.2%）、O:12 和 O:5（12.5%）。碳青霉烯类药物的耐药率很高（64.4%）。在 67 株耐碳青霉烯类药物的分离株中，58 株（86.5%）携带 blaVIM 基因，55 株（82%）携带 blaGES 基因；此外，48 株（71.6%）同时携带 blaVIM 和 blaGES 基因。对 7 株随机选择的分离株进行测序后，鉴定出 blaVIM-2 和 blaGES-5 基因变异体。据我们所知，这是首次同时携带 blaVIM-2 和 blaGES-5 基因的铜绿假单胞菌的描述。
