Metallo Beta Lactamase Producing Pseudomonas Aeruginosa and its Association with Diabetic Foot

Abstract

Pseudomonas aeruginosa strains that produce metallo beta lactamases (MBLs) are becoming increasingly prevalent in wound infections. The aim of the present study is to determine the clinical features, incidence, and to find out the antimicrobial susceptibility pattern of Pseudomonas aeruginosa in diabetic foot infections. Pus samples for bacterial culture were collected from 310 patients admitted with diabetic foot infections. Antimicrobial sensitivity testing was performed by the Kirby-Bauer disc diffusion method. Carbapenem resistance screening and confirmation of MBL was done by the modified imipenem-ethylenediaminetetraacetic acid (EDTA) double disc synergy test. A total of 54 Pseudomonas aeruginosa was isolated from 310 diabetic foot cases. Males were affected more than females with an M:F ratio of 1.6:1. Most patients belonged to the fifth decade of life with a mean age of 49 ± 16.8 years. All the patients were previously diagnosed with diabetes mellitus with duration of the disease at 16 ± 10.2 years and 63% were prescribed oral hypoglycaemic agents. Wound characteristics were classified according to Wagner’s classification majority of Pseudomonas aeruginosa were isolated from Wagner’s II and III grade wound. A number of 26 (89.7%) patients underwent debridement, while 9 (31%) patients underwent toe disarticulation, and 7 (24.1%) patients underwent below-the-knee (BKA) amputation. Antibiotic sensitivity testing revealed 20.3% of Pseudomonas aeruginosa were resistance to carbapenem and 81.8% of these were MBL mediated resistance. Infection with multi drug resistance organisms (MDROs) is common in diabetic foot ulcers and is associated with inadequate glycemic control and increased requirement for surgical treatment. There is a need for continuous surveillance of resistant bacteria to provide the basis for empirical therapy and reduce the risk of complications.