Ansari Maliha, Munir Tehmina, Saad Nadia
Department of Microbiology, Army Medical College, NUST, Islamabad.
J Coll Physicians Surg Pak. 2018 Apr;28(4):274-278. doi: 10.29271/jcpsp.2018.04.274.
To differentiate between Ambler class A, B and D of carbapenemase-producing Enterobacteriaceae by using simple phenotypic methods that can be carried out in the laboratory without requiring any specialised techniques.
Cross-sectional study.
Microbiology Department, Army Medical College, NUST, Islamabad, from November 2015 to November 2016.
Clinical specimens were subjected to identification of Enterobacteriaceae by colony morphology and API 20 E. Carbapenem resistance was detected by applying meropenem disc (10 µg) by disc diffusion method according to CLSI (Clinical Laboratory Standard Institute) criteria. Carbapenemase production among Enterobacteriaceae was detected by Modified Hodge test. Phenotypic methods, Phenylboronic acid (for Class A KPC producing Enterobacteriaceae) and EDTA inhibition tests (for Class B MBL producing Entrobacteriaceae) were applied. Presence of OXA 48 was detected by phenotypic method using imipenem 10 µg, EDTA and PBA discs. Antibiotic susceptibility was determined by Kirby-Bauer disc diffusion method.
Forty-three out of 45 (95.45%) were carbapenemase producers. Thirty-eight out of 43 (88.3%) were KPC producers and 4 out of 43 (11.62%) were MBL producers. All KPC producers were Klebsiella pneumoniae. Among five MBL producers, one each (20%) was Enterobacter cloacae and Escherichia coli and 3 (60%) were Klebsiella pneumoniae. All MBL producers were resistant to aztreonam and amoxicillin/clavulanate. Two of the KPC producing Klebsiella pneumoniae were pan-drug resistant (resistant to colistin and tigecycline). Two were non-carbapenemase producers.
Enterobacteriaceae strains producing KPC-type carbapenemase were the most prevalent (88.3%) in the studied healthcare setup.
通过使用可在实验室中进行且无需任何专门技术的简单表型方法，区分产碳青霉烯酶肠杆菌科细菌的安布勒A类、B类和D类。
横断面研究。
2015年11月至2016年11月，伊斯兰堡国立科技大学陆军医学院微生物学系。
临床标本通过菌落形态和API 20 E鉴定肠杆菌科细菌。根据临床实验室标准协会（CLSI）标准，采用纸片扩散法应用美罗培南纸片（10μg）检测碳青霉烯耐药性。通过改良 Hodge试验检测肠杆菌科细菌中产碳青霉烯酶情况。应用表型方法，即苯基硼酸（用于产A类KPC的肠杆菌科细菌）和EDTA抑制试验（用于产B类MBL的肠杆菌科细菌）。使用亚胺培南10μg、EDTA和PBA纸片通过表型方法检测OXA 48的存在。通过 Kirby-Bauer纸片扩散法测定抗生素敏感性。
45株中有43株（95.45%）为产碳青霉烯酶菌株。43株中有38株（88.3%）为产KPC菌株，43株中有4株（11.62%）为产MBL菌株。所有产KPC菌株均为肺炎克雷伯菌。在5株产MBL菌株中，阴沟肠杆菌和大肠埃希菌各有1株（20%），肺炎克雷伯菌有3株（60%）。所有产MBL菌株对氨曲南和阿莫西林/克拉维酸耐药。2株产KPC的肺炎克雷伯菌对多种药物耐药（对黏菌素和替加环素耐药）。2株为非产碳青霉烯酶菌株。
在所研究的医疗机构中，产KPC型碳青霉烯酶的肠杆菌科菌株最为常见（88.3%）。
