Department of Microbiology, Jai Prakash Narayan Apex Trauma Centre, New Delhi, India.
Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India.
Indian J Med Res. 2019 Feb;149(2):216-221. doi: 10.4103/ijmr.IJMR_1_18.
BACKGROUND & OBJECTIVES: Nosocomial infections caused by multidrug-resistant, Pseudomonas species have become a major clinical and public health concern. The aim of this study was to characterize phenotypic and genotypic profile of antimicrobial resistance (AMR) in Pseudomonas spp. isolated from hospitalized patients.
A total of 126 consecutive, non-duplicate isolates of Pseudomonas spp. isolated from various clinical samples were included in the study over a period of two years. Identification and antimicrobial sensitivity was performed using automated culture system according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. Phenotypic detection of extended-spectrum β-lactamases (ESBLs), Amp-C β-lactamase (AmpC) and metallo-β-lactamases (MBLs) were done by various combinations of disc-diffusion and E-test methods, followed by polymerase chain reaction-based detection of β-lactamase-encoding genes.
Among 126 clinical isolates, 121 (96.1%) isolates were identified as Pseudomonas aeruginosa. Most of the isolates were recovered from pus sample, 35 (27.8%) followed by urine, 25 (19.84%); endotracheal aspirate, 24 (19.04%); blood, 14 (11.11%) and sputum, four (3.17%). The highest rate of resistance was against ticarcillin-clavulanic acid, 113 (89.7%) followed by meropenem, 92 (72.5%) and ceftazidime, 91 (72.3%). Overall, ESBLs, AmpC and carbapenemase production was detected in 109 (96.4%), 64 (50.8%) and 105 (94.6%) isolates by phenotypic methods. The most prevalent ESBL gene was blain 72 (57.1%) and the least prevalent was blain 19 (15.1%) isolates. AmpC gene was seen less compared to ESBL gene. The most prevalent carbapenemases gene was bla41 (46.06%) followed by bla and bla.
INTERPRETATION & CONCLUSIONS: Our findings suggested that a high rate of ESBLs and carbapenemases production was observed in Pseudomonas spp. Therefore, phenotypic and genotypic detection of AMR needs to be combined for better characterization of resistance patterns in Pseudomonas spp.
由多药耐药铜绿假单胞菌引起的医院感染已成为一个主要的临床和公共卫生问题。本研究的目的是描述从住院患者中分离的铜绿假单胞菌的表型和基因型抗菌药物耐药（AMR）特征。
在两年的时间里，从各种临床样本中连续分离出 126 株非重复的铜绿假单胞菌。根据临床和实验室标准协会（CLSI）的建议，使用自动培养系统进行鉴定和抗菌药物敏感性检测。通过纸片扩散和 E 试验方法的各种组合，以及基于聚合酶链反应的β-内酰胺酶编码基因检测，对超广谱β-内酰胺酶（ESBLs）、Amp-Cβ-内酰胺酶（AmpC）和金属β-内酰胺酶（MBLs）进行表型检测。
在 126 株临床分离株中，121 株（96.1%）鉴定为铜绿假单胞菌。大多数分离株来自脓液样本，35 株（27.8%），其次是尿液，25 株（19.84%）；气管吸出物，24 株（19.04%）；血液，14 株（11.11%）和痰液，4 株（3.17%）。耐药率最高的是替卡西林-克拉维酸，113 株（89.7%），其次是美罗培南，92 株（72.5%）和头孢他啶，91 株（72.3%）。总的来说，109 株（96.4%）、64 株（50.8%）和 105 株（94.6%）分离株通过表型方法检测到 ESBLs、AmpC 和碳青霉烯酶的产生。最常见的 ESBL 基因是 blain 72（57.1%），最少见的是 blain 19（15.1%）。与 ESBL 基因相比，AmpC 基因较少。最常见的碳青霉烯酶基因是 bla41（46.06%），其次是 bla 和 bla。
我们的研究结果表明，铜绿假单胞菌中 ESBLs 和碳青霉烯酶的产生率很高。因此，需要结合表型和基因型检测来更好地描述铜绿假单胞菌的耐药模式。
