The rapid spread of metallo-β-lactamase (MBL) producing clinical pathogens is a matter of great concern. The presence of MBL in hospitals poses more threat for public health as MBL positive isolates show resistance to most of the antibiotics. The current study was carried out to determine the prevalence of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs), particularly bla_VIM in clinical multi-drug resistant isolates from two tertiary care hospitals in Pakistan. A total of 57 clinical isolates were included in the study where the isolates were collected from two public tertiary care hospitals in Lahore. The isolates were screened for ESBLs and MBLs production by phenotypic method and PCR was performed to detect the presence of bla_VIM genes. Out of 57 clinical isolates, the resistance against meropenem was noted to be highest in MBL producing strains (96%) as well as among all the bacterial strains (82%). Of these 57 isolates, 32 (56%) displayed MBLs production as accessed by combined disc method. In MBLs producing organisms, PCR amplification confirmed 6 (18.7%) isolates carried the bla_VIM-1 gene, whereas bla_VIM-2 gene was not identified in any strain. The prevalence of ESBL producing organisms was recorded to be 87.5%. It is concluded that there is an increasing trend of MBL producing gram negative bacterial strains: P. aeruginosa > K. pneumonia > E. coli > A. baumannii >P. vulgaris, respectively. This study demonstrated the emergence of carbapenemase-producing Gram-negative pathogens implicated in healthcare-related infections.

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Index Terms- Metallo-β-lactamase, Carbapenemase, Multidrug-Resistant, Pseudomonas spp.