An-Najah National University, Department of Biology and Biotechnology, Nablus, Palestine.
Braz J Biol. 2021 Jun 28;82:e239868. doi: 10.1590/1519-6984.239868. eCollection 2021.
Fluoroquinolones are important antimicrobial agents for the treatment of Pseudomonas infections. A total of 11 isolates of P. aeruginosa were collected from different clinical samples from different medical centers in the North West Bank-Palestine during 2017. In this study, resistance to fluoroquinolones and secretions of β-lactamases were detected by phenotypic methods, while presence of β-lactamase gene sequences and other virulence factors were detected by PCR technique. PCR product for gyrA, parC and parE genes were sequenced for further analyses. The phylogenetic analyses, population diversity indices and haplotypes determination were conducted using computer programs MEGA version 6, DnaSP 5.1001 and median-joining algorithm in the program Network 5, respectively. Results of this study showed that the MIC for ciprofloxacin and norfloxacin had a range of 32-256 µg/ml. In addition, all isolates carried either exoT or exoT and exoY genes, different β-lactamase genes and 82% of these isolates harbored class 1 integrons. Analyses of the gyrA, parC and parE sequences were found to be polymorphic, had high haplotype diversity (0.945-0.982), low nucleotide diversity (0.01225-0.02001) and number of haplotypes were 9 for each gyrA and parE genes and 10 haplotypes for parC gene. The founder haplotypes being Hap-1 (18%), Hap-2 (27.3%) and Hap-6 (9.1%) for gyrA, parC and parE genes, respectively. Two of ParE haplotypes were detected as indel haplotypes. The Median-joining- (MJ) networks constructed from haplotypes of these genes showed a star-like expansion. The neutrality tests (Tajima's D test and Fu's Fs test) for these genes showed negative values. Palestinian fluoroquinolone resistant P. aeruginosa strains showed high MIC level for fluoroquinolones, β-lactamase producers, carried type III secretion exotoxin-encoding genes, most of them had integrase I gene and had high level of mutations in QRDR regions in gyrA, parC and parE genes. All these factors may play an important role in the invasiveness of these strains and make them difficult to treat. Isolation of these strains from different medical centers, indicate the need for a strict application of infection control measures in Medical centers in the North West Bank-Palestine that aim to reduce expense and damage caused by P. aeruginosa infections. Molecular analyses showed that Palestinian fluoroquinolone resistant P. aeruginosa haplotypes are not genetically differentiated; however, more mutations may exist in these strains.
氟喹诺酮类药物是治疗铜绿假单胞菌感染的重要抗菌药物。本研究于 2017 年从巴勒斯坦约旦河西岸不同医疗中心的不同临床标本中收集了 11 株铜绿假单胞菌。本研究采用表型方法检测氟喹诺酮类药物耐药性和β-内酰胺酶的分泌，采用 PCR 技术检测β-内酰胺酶基因序列和其他毒力因子。对 gyrA、parC 和 parE 基因的 PCR 产物进行测序，进一步分析。使用 MEGA 版本 6、DnaSP 5.1001 和 Network 5 中的中位数连接算法等计算机程序分别进行系统发育分析、种群多样性指数和单倍型确定。研究结果表明，环丙沙星和诺氟沙星的 MIC 范围为 32-256μg/ml。此外，所有分离株均携带 exoT 或 exoT 和 exoY 基因、不同的β-内酰胺酶基因，且 82%的这些分离株携带 1 类整合子。gyrA、parC 和 parE 序列分析发现其多态性，具有较高的单倍型多样性（0.945-0.982）、较低的核苷酸多样性（0.01225-0.02001），gyrA 和 parE 基因的单倍型数分别为 9 个，parC 基因的单倍型数为 10 个。gyrA、parC 和 parE 基因的起始单倍型分别为 Hap-1（18%）、Hap-2（27.3%）和 Hap-6（9.1%）。两个 ParE 单倍型被检测为插入缺失单倍型。基于这些基因的单倍型构建的中位连接（MJ）网络显示出星状扩张。这些基因的中性检验（Tajima 的 D 检验和 Fu 的 Fs 检验）显示为负值。巴勒斯坦氟喹诺酮耐药铜绿假单胞菌分离株对氟喹诺酮类药物的 MIC 水平较高，产β-内酰胺酶，携带 III 型分泌外毒素编码基因，大多数菌株含有整合酶 I 基因，gyrA、parC 和 parE 基因的 QRDR 区突变水平较高。所有这些因素可能在这些菌株的侵袭性中发挥重要作用，使它们难以治疗。从不同医疗中心分离出这些菌株表明，需要在约旦河西岸的医疗中心严格应用感染控制措施，以减少铜绿假单胞菌感染造成的费用和损害。分子分析表明，巴勒斯坦氟喹诺酮耐药铜绿假单胞菌的单倍型没有遗传分化；然而，这些菌株可能存在更多的突变。
