González-Olvera Eliab M, Pérez-Morales Rebeca, González Zamora Alberto, Castro-Escarpulli Graciela, Palma-Martínez Ingrid, Alba-Romero José J
Laboratorio de Microbiología Clínica, Facultad de Ciencias Químicas, Universidad Juárez del Estado de Durango, Gómez Palacio, Durango, México.
Laboratorio de Biología Celular y Molecular, Facultad de Ciencias Químicas, Universidad Juárez del Estado de Durango, Gómez Palacio, Durango, México.
J Infect Dev Ctries. 2019 May 31;13(5):374-383. doi: 10.3855/jidc.10953.
Pseudomonas aeruginosa is the second most prevalent opportunistic pathogen causing nosocomial infections in Mexico. This study evaluated antibiotic resistance, production of virulence factors and clonal diversity of P. aeruginosa strains isolated from patients undergoing nosocomial infections in public hospitals of northeastern Mexico.
Ninety-two P. aeruginosa isolates from urine culture, Foley catheter, ear, wounds, respiratory tract secretions, scalp, blood culture, bronchoalveolar lavage, expectoration and cerebrospinal fluid causing nosocomial infections were analyzed. The isolates were identified by MALDI-TOF and antibiotic resistance profiles obtained by MicroScan®. The production of virulence factors was analyzed with spectrophotometric techniques and isolates genotyped by ERIC-PCR.
Out of the 92 isolates, 26 (28.2%) were found to be multidrug resistant (MDR); 21 (22.7%) were classified as extremely drug resistant (XDR). Highest resistance rate was found for gatifloxacin (42%) while ciprofloxacin accounted for the antibiotic with the lowest resistance rate (2%). Bronchoalveolar lavage isolates produced the highest amounts of virulence factors: biofilm (44.4% ± 2.7%), elastase (58.5% ± 4.3%), alkaline protease (60.1% ± 5.0%); except for pyocyanin production. The ERIC-PCR assay showed 83 genetic patterns (90% clonal diversity) and 13 isolates had 100% genetic similarity, forming 4 real clones, 3 of these clones were obtained from different anatomical site and/or hospital.
Antibiotic resistance and virulence factors production was heterogeneous among samples analyzed. Genotyping of P. aeruginosa strains showed high genetic diversity in the studied isolates.
铜绿假单胞菌是墨西哥引起医院感染的第二大常见机会致病菌。本研究评估了从墨西哥东北部公立医院医院感染患者中分离出的铜绿假单胞菌菌株的抗生素耐药性、毒力因子产生情况和克隆多样性。
分析了92株从尿液培养物、导尿管、耳部、伤口、呼吸道分泌物、头皮、血培养、支气管肺泡灌洗、咳痰和脑脊液中分离出的导致医院感染的铜绿假单胞菌。通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）鉴定分离株，并通过MicroScan®获得抗生素耐药谱。采用分光光度技术分析毒力因子的产生情况，并通过肠杆菌基因间重复序列聚合酶链反应（ERIC-PCR）对分离株进行基因分型。
在92株分离株中，26株（28.2%）被发现为多重耐药（MDR）；21株（占22.7%）被归类为广泛耐药（XDR）。加替沙星的耐药率最高（42%），而环丙沙星是耐药率最低的抗生素（2%）。支气管肺泡灌洗分离株产生的毒力因子量最高：生物膜（44.4%±2.7%）、弹性蛋白酶（58.5%±4.3%）、碱性蛋白酶（60.1%±5.0%）；除了绿脓菌素的产生。ERIC-PCR分析显示有83种基因模式（克隆多样性为90%），13株分离株具有100%的基因相似性，形成4个真正的克隆，其中3个克隆来自不同的解剖部位和/或医院。
在所分析的样本中，抗生素耐药性和毒力因子的产生情况存在异质性。铜绿假单胞菌菌株的基因分型显示所研究的分离株具有高度的遗传多样性。
