Prevalence of Extended Spectrum β-Lactamases in Multi-drug Resistant Pseudomonas aeruginosa from Diabetic Foot Patients.

BACKGROUND: Pseudomonas aeruginosa is one of the major pathogen associated with acute tissue damage in patients with diabetic foot ulcer (DFU). Antibiotic resistance in P. aeruginosa often bodes unpredictable and unfavourable clinical outcomes, owing to a variety of intrinsic and acquired molecular mechanisms. The study aimed to determine the frequency of ESBLs in Multi-drug resistant P. aeruginosa from diabetic foot patients.

METHOD: Present study's duration was one year and 100 patients with DFU were enrolled. All the pus samples were subjected to the bacterial culture, gram staining, catalase test, oxidase test and antimicrobial susceptibility pattern was ascertained using the phenotypic method. The presences of genes encoding extended spectrum beta-lactamase enzyme were determined by PCR.

RESULT: Of 23 positive isolates of P. aeruginosa, Polymxin B showed greater susceptibility of all antibiotics used. 10 isolates were ESBLs positive as detected by double disk diffusion test. The positive ESBL strain showed an increase of ≥5mm in the zone of inhibition of the combination discs in comparison to the alone ceftazidime disc. The PCR-based ESBLs positivity was also tested for TEM-1, SHV-1, PER-1, and VEB-1. Where: (07/10) strains carried SHV-1, (05/10) strains were positive for TEM-1, while none of the isolates were PCR-positive for PER-1 and VEB-1.

CONCLUSION: P. aeruginosa isolates shows a difference in pattern of ESBL genes compared to that of other such endeavours. Polymxin B was found to be most effective against the tested P. aeruginosa isolates and SHV-1 was most common ESBL among these strains.