Phenotypic Detection of Different Classes of Beta-lactamases among the Isolates of Carbapenem Resistant Enterobacteriaceae
Gautam K, Lekhak B,Triphatee PP2 and Bhatta DR
Carbapenem-resistant Enterobacteriaceae has challenged the therapeutic efficacy and raised the most worrisome global issue of public health importance. The study was conducted to determine the burden of carbapenem resistant isolates of Enterobacteriaceae producing different types of β-lactamases. During the study period, a total of 310 enterobacterial pathogens were isolated and identified from the specimens of urine, blood, pus, sputum, stool and body fluids obtained from the patients visiting Kanti Children Hospital. By Kirby Bauer disc diffusion method, β-lactamase producers and multidrug resistant isolates were detected and ESBLs and carbapenemase producers were screened among them. Phenotypic detection of ESBLs was done by Combination disc test. Modified Hodge test was employed for detection of carbapenemase producers and they were typed into different molecular classes by inhibitor based combination disk tests. A total of 251 (81.0%) isolates were β-lactamase producers and 213 (68.7%) were multidrug resistance among the Enterobacteriaceae. Typification of β-lactamases from 23 (7.4%) Modified Hodge Test positive isolates assorts 4 as KPC producers, 11 as MBL producers, 3 as AmpC β-lactamase producers and 1 with both KPC and MBL enzyme while 4 remained unclassified. The majority of carbapenemresistants were E. coli (52.1%) followed by K. pneumoniae (34.8%) and most of the CRE were resistant (56.52%) to all the combinations of ESBL test. Various classes of carbapenemases were found to have emerged among Enterobacteriaceae in Nepal. Since, the profound variation is found in beta-lactamases of CRE, to reduce the risk of severe calamity effective detection procedures are mandatory in all the clinical laboratories.