Molecular Characterization of Bla CTXM GP1 Gene in Pseudomonas Spp. Isolated From Diabetic Foot Ulcers

Malik M

Published on: 2025-10-25

Abstract

Pseudomonas aeruginosa is an opportunistic Gram negative pathogen frequently isolated from diabetic foot ulcers (DFUs), contributing to delayed healing and higher amputation risk. The emergence of extended spectrum β lactamase (ESBL)–producing strains complicates treatment. This study aimed to isolate P. aeruginosa from DFUs in Punjab, Pakistan, determine antibiotic susceptibility profiles, and detect the presence of the bla CTXM GP1 resistance gene.

Ninety pus samples were collected from diabetic patients between September 2024 and May 2025. Microbiological and biochemical methods, including Gram staining and PCR, were used for identification and gene detection. Antibiotic susceptibility testing (AST) assessed resistance to cefotaxime, cefoxitin, ciprofloxacin, and imipenem. P. aeruginosa was isolated in 50% (45/90) of samples. All isolates (100%) were resistant to cefotaxime and cefoxitin, while showing 85% sensitivity to ciprofloxacin and full sensitivity (100%) to imipenem. PCR analysis revealed the absence of the bla CTXM GP1 gene in all isolates. Despite high resistance to certain cephalosporins, the lack of bla CTXM GP1 indicates other mechanisms drive this resistance. Imipenem and ciprofloxacin remain effective treatment options. Ongoing surveillance and molecular investigations are essential.