Detection of the Production of KPC, NDM, OXA-48, VIM and IMP-Type Carbapenemases by Gram-Negative Bacilli in Resource-Limited Setting

Increased bacterial antibiotic resistance is a global public health problem; this problem is all the more worrying with the appearance and spread of carbapenemases. This study aimed to identify the production and distribution of carbapenemases in Gram-negative bacilli isolated in Douala. A cross-sectional study was conducted from January 2023 to March 2024 (1 year two months)). Included in the study were all strains of Gram-negative bacilli isolated in one of the two selected hospitals and resistant to at least 3 classes of antibiotics (multi-resistant). These strains were identified using biochemical tests with colorimetric revelation (Vitek 2). After which, they were subjected to an antibiogram by the agar diffusion method with a range of 20 standard antibiotics. Once confirmed to be multi-resistant, the strains were tested for the production of one of the five carbapenemases detected by immunochromatographic technique (OXA-48, NDM, IMP, VIM, KPC) using the rapid detection kit "NG-TEST/CARBA 5”. Statistical analysis of the data was carried out using Epi info version 7.2.2.6 and Excel 2013 software. A total of 475 strains of gram-negative bacilli were collected during the study period, 40 multi-resistant strains were identified, mainly in the ECBU samples (47.0%); 37.5% of the multi-resistant strains produced the carbapenemases detected with a higher frequency at the General Hospital (53.3%). NDM-type carbapenemase was the most frequently identified (47.1%); The prevalence of carbapenemase production was higher in E. coli (66.7%), which was also the most isolated species (22.5%) Amikacin was the most active antibiotic on multi-strains resistant and carbapenemase-producing strains OXA-48 and NDM. The production of carbapenemases is increasing given the figures obtained in this study compared to those obtained in 2018.