Clinico‑microbiological study and antibiotic resistance profile of meca and ESBL gene prevalence in patients with diabetic foot infections

Abstract

Diabetic foot infections (DFIs) constitute a major complication of diabetes mellitus. DFIs contribute to the development of gangrene and non‑traumatic lower extremity amputations with a lifetime risk of up to 25%. The aim of the present study was to identify the presence of neuropathy and determine the ulcer grade, microbial profile and phenotypic and genotypic prevalence of the methicillin‑resistance gene mecA and extended spectrum β‑lactamase (ESBL)‑encoding genes in bacterial isolates of DFI in patients registered at the Pakistan Institute of Medical Sciences (Islamabad, Pakistan). The results indicated that 46/50 patients (92%), exhibited sensory neuropathy. The most common isolate was Staphylococcus aureus (25%), followed by Pseudomonas aeruginosa (P. aeruginosa; 18.18%), Escherichia coli (16.16%), Streptococcus species (spp.) (15.15%), Proteus spp. (15.15%), Enterococcus spp. (9%) and Klebsiella pneumoniae (K. pneumoniae; 3%). The prevalence of the mecA gene was found to be 88% phenotypically and 84% genotypically. K. pneumoniae was shown to have the highest percentage of ESBL producers with a prevalence of 66.7% by double disk synergy test, and 100% by the cefotaxime + clavulanic acid/ceftazidime + clavulanic acid combination disk test. P. aeruginosa and K. pneumoniae had the highest (100%) proportion of metallo β‑lactamase producers as identified by the EDTA combination disk test. The overall prevalence of β‑lactamase (bla)‑CTX‑M, bla‑CTX‑M‑15, bla‑TEM, bla‑OXA and bla‑SHV genes was found to be 76.9, 76.9, 75.0, 57.7 and 84.6%, respectively, in gram‑negative DFI isolates. The prevalence of mecA and ESBL‑related genes was found to be alarmingly high in DFIs, since these genes are a major cause of antibiotic treatment failure.