Universidad de Panamá, Programa de Maestría en Ciencias Biológicas, Panama.
Universidad de Panamá, Escuela de Biología, Departmento de Genética y Biología Molecular, Panama; Instituto de Investigaciones Científicas y Servicios de Alta Tecnología de Panamá (INDICASAT-AIP), Panama.
Braz J Infect Dis. 2021 Jan-Feb;25(1):101038. doi: 10.1016/j.bjid.2020.11.003. Epub 2020 Dec 4.
Pseudomonas aeruginosa is an important causative agent of nosocomial infections. As pathogen, P. aeruginosa is of increasing clinical importance due to its ability to develop high-level multidrug resistance (MDR).
The aim of the present study was to better understand the intrinsic virulence of circulating strains of Pseudomonas aeruginosa, by surveying and characterizing the antibiotic resistance profiles and prevalence of virulence factors in 51 clinical isolates of P. aeruginosa obtained from children admitted to Hospital del Niño-Panamá during the period of October 2016 until March 2017. Antimicrobial susceptibilities were assessed by determining the minimum inhibitory concentration for 12 antibiotics against P. aeruginosa clinical isolates using the VITEK system (https://www.biomerieux.com). Additionally, all isolates were examined by Polymerase Chain Reaction (PCR) for the presence of components of the MexAB-OprM efflux pump system (mexABR) and pyoverdine receptor genes and betalactamases resistance genes (ESBL) using gene-specific primers.
A total of 51 pyoverdine producing clinical isolates were analyzed, all of which expressed resistance genes such as genes of the MexAB-OprM efflux pump system (mexABR) and pyoverdine receptor genes (fpvA). Out of 51 MDR isolates, 22 were ESBL producers. The most common ESBL gene was blaTEM expressed by 43% of the isolates. The isolates tested in this study showed increased resistance to antibiotics in the following categories: (i) penicillins (ampicillin (69%), piperacillin (22%); (ii) pyrimethamines (trimethoprim, 65%); (iii) nitrofurans (nitrofurantoin, 63%), and (iv) third-generation cephalosporin cefotaxime (53%). These results underscore a high prevalence of MDR amongst clinical isolates from Panama.
The present study indicates that prevalence of BlaTEM-carrying strains is increasing with subsequent multidrug resistance in Panamá and as well reported worldwide. The virulent factors identified in this study provide valuable information regarding the prevalence of resistance genes and their potential impact on treatments that exploit the unique physiology of the pathogen. To prevent further spread of MDR, the proportions of resistant strains of Pseudomonas aeruginosa should be constantly evaluated on healthcare institutions of Panamá. More importantly, this information can be used to better understand the evolution and dissemination of strains hoping to prevent the development of resistance in Pseudomonas aeruginosa. Future studies quantifying the expression of these virulent genes will emphasize on the acquisition of multidrug resistance.
铜绿假单胞菌是医院感染的重要病原体。由于其产生高水平多药耐药（MDR）的能力，铜绿假单胞菌作为病原体的临床重要性日益增加。
本研究的目的是通过调查和描述 51 株来自 2016 年 10 月至 2017 年 3 月期间在巴拿马儿童医院住院的儿童的铜绿假单胞菌临床分离株的抗生素耐药谱和毒力因子流行情况，更好地了解循环菌株的固有毒力。使用 VITEK 系统（https://www.biomerieux.com）测定 12 种抗生素对铜绿假单胞菌临床分离株的最小抑菌浓度，以评估抗菌药物敏感性。此外，所有分离株均通过聚合酶链反应（PCR）检测 MexAB-OprM 外排泵系统（mexABR）和吡咯并戊酸受体基因以及β-内酰胺酶耐药基因（ESBL）成分的存在，使用基因特异性引物。
共分析了 51 株产吡咯并戊酸的临床分离株，所有分离株均表达耐药基因，如 MexAB-OprM 外排泵系统（mexABR）和吡咯并戊酸受体基因（fpvA）。在 51 株 MDR 分离株中，有 22 株产 ESBL。最常见的 ESBL 基因是 blaTEM，占分离株的 43%。本研究中检测到的分离株对以下几类抗生素的耐药性增加：（i）青霉素类（氨苄西林（69%）、哌拉西林（22%）；（ii）嘧啶类（甲氧苄啶，65%）；（iii）硝基呋喃类（呋喃妥因，63%）；和（iv）第三代头孢菌素头孢噻肟（53%）。这些结果突出表明，在巴拿马，临床分离株的 MDR 患病率很高。
本研究表明，携带 BlaTEM 的菌株的流行率在巴拿马以及世界范围内不断增加，同时也出现了多药耐药性。本研究中鉴定的毒力因子为耐药基因的流行情况及其对利用病原体独特生理学的治疗方法的潜在影响提供了有价值的信息。为了防止 MDR 的进一步传播，应定期评估巴拿马医疗机构中铜绿假单胞菌耐药株的比例。更重要的是，这些信息可以用来更好地了解菌株的进化和传播，希望防止铜绿假单胞菌产生耐药性。未来定量表达这些毒力基因的研究将强调获得多药耐药性。
