Frequency and Benefits of Oxa- 48-Like Gene Detection in Imipenem Resistant Enterobacterales Using Phenotypic Methods

Objectives: To determine frequency of OXA-48 like gene in CRE and to find effectiveness of phenotypic methods for OXA-48 like gene detection. Study Design: cross-sectional study. Place and Duration of Study: Pakistan Railway hospital (PRH) Rawalpindi, Pakistan from Oct 2022 to Sep 2023. Methodology: One hundred and four samples of pus, HVS, urine, sputum was included in the study, inoculated on suitable culture media, and then incubated for 48 hours. Microscopical examination was done after gram staining followed by biochemical testing. Susceptibility of isolates was tested by Disk Diffusion method and MIC of Imipenem was tested against all isolates by using E strips. Carba NP, mCIM, eCIm test were applied on CRE isolates. Isolates found negative for eCIM were tested with temocillin antibiotic disc. Isolates found resistant to temocillin with zone of Inhibition less than 11mm were labelled positive for OXA- 48 like gene. Results: Out of total 104 CRE isolates 31 (30%) were resistant to temocillin with the sensitivity zone less than 11 mm and were labelled OXA-48 like positive. The frequency of OXA-48 like was determined 30%. Conclusion: Frequency of OXA-48 like gene was found to be 30%. Phenotypic methods are useful and reliable in the early and speedy detection of OXA-48 like gene in CRE isolates.