ß-LACTAMASE-ASSOCIATED RESISTANCE PHENOTYPES AMONGST MULTIDRUG RESISTANT BACTERIA ISOLATED IN A SCHOOL HOSPITAL OF WEST CAMEROON

The present survey aimed at characterizing a few resistance mechanisms that multidrug resistant bacteria isolated in Bangangte (West-Cameroon) express to tolerate the action of beta-lactams. The target traits included extended spectrum beta-lactamase (ESBL), inducible cephalosporinase (IC), high and low level penicillinases (HLP and LLP, respectively), high and low level cephalosporinases (HLC and LLC, respectively) and inhibitor-resistant penicillinase (IRP) in Gram-negative bacteria. In Gram-positive, they were limited to IC and ESBL. All detections were conducted by disk diffusion with Amoxicillin (30 µg), Amoxicillin/clavulanic-acid (20/10 µg), Piperacillin (100 µg), Imipenem (10 µg), Cefazolin (30 µg), Cefoxitin (30 µg), Cefotaxim (30 µg), Ceftazidim (10 µg), Ceftriaxon (30 µg) and Aztreonam (30 µg). A total of 103 isolates were included in the study and Gram-negative bacilli members of the Enterobacteriaceae family predominated (70%). The most tolerated antibacterials were Amoxicillin and Amoxicillin/clavulanic-acid. Seven resistance mechanisms were detected (several could be expressed by the same strain). Their rates varied from 9.7% with HLC through 56.3% with LLC. All Pseudomonas expressed LLC while the highest ESBL rate was observed in E. coli (84.6%). Staphylococcus aureus were also found to express ESBL (70%). Overall, LLC, IC and ESBL-expression appeared first, second and third most frequently detected (56.3%, 51.5%, and 37.9%, respectively). These findings indicated that antibiotic therapy is seriously threatened in the setting, in connection with the low likelihood of therapeutic success with available s-lactams. They also draw attention on the necessity for appropriate choice of drug combination in probabilistic treatment in order to use sustainably all drugs while providing better care and minimizing resistance selection.