Phenotypic detection of Metallo-β-Lactamase (MBL) in Imipenem-Resistant Pseudomonas aeruginosa, a study from a tertiary care hospital in Peshawar, Pakistan

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Research Paper 01/06/2021
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Phenotypic detection of Metallo-β-Lactamase (MBL) in Imipenem-Resistant Pseudomonas aeruginosa, a study from a tertiary care hospital in Peshawar, Pakistan

Numan Saleh Zada, Fazli Bari, Zulfiqar Ali Malik, Fareeha Hameed Bangash, Rashid Mansoor, Aamer Ali Shah, Malik Badshah, Samiullah Khan
Int. J. Biosci.18( 6), 120-128, June 2021.
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Production of metallo-β-Lactamase (MBL) by Pseudomonas aeruginosa has emerged as one of the most clinically worrisome resistance mechanisms. The present study aimed phenotypic detection of MBL production in clinical isolates of Imipenem resistant P. aeruginosa. About 245 non-duplicated P. aeruginosa isolates were collected during a ten-month study duration from a tertiary care hospital of Peshawar, Pakistan. The isolation of the P. aeruginosa isolates was done from high vaginal swab, pus, urine, sputum, blood, and other body fluids. Antibiotic susceptibility profile of the tested isolates was investigated by Kirby-Bauer disc diffusion method. The isolates were further screened for MBL production by Imipenem- EDTA combined disc test (CDT). Among 245 clinical isolates, percentage of outdoor and admitted patients were 62% and 37%, whereas gender-wise ratio includes 57% male and 42% female patients respectively. Burn unit showed highest number of P. aeruginosa isolates among admitted patients, followed by endocrinology, surgical, orthopedics, gynecology, urology, ENT, skin, pediatrics, and medical ward. Out of total isolates, 15% isolates showed resistance towards Imipenem by Kirby-Bauer method. Thirty-two (13%) out of 245 isolates were found positive for MBL production by CDT method.  All MBL producers showed a notable resistance against imipenem, cefepime, aztreonam while sensitivity was observed towards all the other tested antibiotics. The P. aeruginosa isolates are rapidly developing resistance against effective therapeutic agents especially carbapenem, which is of serious concern. Therefore, rapid detection of MBLs in P. aeruginosa isolates is essential for controlling the spread of MBL-encoded genes and efficient treatment of patients.


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