Department of Medical Microbiology, Postgraduate Institute of Medical Education & Research, Chandigarh, India.
Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
Indian J Med Res. 2019 Feb;149(2):208-215. doi: 10.4103/ijmr.IJMR_172_18.
BACKGROUND & OBJECTIVES: The increasing prevalence of extended-spectrum β-lactamases (ESBLs) has abated therapeutic options worldwide. This study was undertaken to investigate the molecular profile and resistance patterns of ESBLs among clinical isolates of Escherichia coli and Klebsiella pneumoniae at four tertiary care centres in India.
Clinical isolates of E. coli and K. pneumoniae were collected from the All India Institute of Medical Sciences (AIIMS), New Delhi; the Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Puducherry; Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh and Christian Medical College (CMC), Vellore, over one and a half year period. Antimicrobial susceptibility was determined by Kirby-Bauer disc diffusion method. ESBLs were confirmed phenotypically, and multiplex PCR was performed to identify genes for β-lactamases (bla, bla, bla, bla, bla, bla and bla).
Among 341 E. coli isolates collected during the study period, 171 (50%) harboured bla, 145 (43%) bla,70 (21%) bla, 19 (6%) bla and four (1%) harboured bla. Phenotypically, combined disc test detected ESBL production in 98/298 (33%) E. coli. Among 304 K. pneumoniae isolates, 115 (38%), 89 (29%), 83 (27%), 64 (21%) and two (0.6%) harboured bla, bla, bla, bla and bla, respectively. Combined disc test (CDT) detected ESBL production in 42 per cent K. pneumoniae. Most of the blapositive isolates were also bla positive. The carbapenem susceptibility ranged from 56 to 88 per cent for E. coli and from 20 to 61 per cent for K. pneumoniae. Antibiotic sensitivity patterns showed that colistin (CST) was the most sensitive drug for both E. coli (271/274, 99%) and K. pneumoniae (229/234, 98%).
INTERPRETATION & CONCLUSIONS: The prevalence of ESBL among four study centres varied, and bla bla and bla were the most common genotypes in E. coli and K. pneumoniae isolates in India. The growing carbapenem resistance and emerging colistin resistance warrant the judicious use of these antimicrobials.
扩展型β-内酰胺酶（ESBLs）的患病率不断上升，这在全球范围内降低了治疗选择。本研究旨在调查印度四家三级护理中心的大肠杆菌和肺炎克雷伯菌临床分离株中 ESBL 的分子特征和耐药模式。
在一年半的时间里，从全印度医学科学研究所（AIIMS）、新德里；贾瓦哈拉尔·英帕尔研究生医学教育与研究学院（JIPMER）、本地治里；PGIMER，昌迪加尔和基督教医学院（CMC），维洛尔收集了大肠杆菌和肺炎克雷伯菌的临床分离株。通过 Kirby-Bauer 圆盘扩散法测定抗生素敏感性。通过表型确认 ESBL，并用多重 PCR 鉴定β-内酰胺酶基因（bla、bla、bla、bla、bla、bla 和 bla）。
在研究期间收集的 341 株大肠杆菌中，171 株（50%）携带 bla，145 株（43%）携带 bla，70 株（21%）携带 bla，19 株（6%）携带 bla，4 株（1%）携带 bla。表型上，联合圆盘试验检测到 298 株大肠杆菌中有 98 株（33%）产 ESBL。在 304 株肺炎克雷伯菌中，分别有 115 株（38%）、89 株（29%）、83 株（27%）、64 株（21%）和 2 株（0.6%）携带 bla、bla、bla、bla 和 bla。联合圆盘试验（CDT）检测到 42%的肺炎克雷伯菌产 ESBL。大多数 bla 阳性分离株也为 bla 阳性。碳青霉烯类药物的敏感性范围为大肠杆菌的 56%至 88%，肺炎克雷伯菌的 20%至 61%。抗生素敏感性模式表明，多粘菌素（CST）对大肠杆菌（271/274，99%）和肺炎克雷伯菌（229/234，98%）最敏感。
四个研究中心的 ESBL 流行率不同，bla、bla 和 bla 是印度大肠杆菌和肺炎克雷伯菌分离株中最常见的基因型。碳青霉烯类药物耐药性不断增加和多粘菌素类药物耐药性的出现，需要合理使用这些抗生素。
