Phenotypic Characterization of Extended Spectrum Beta-lactamase, Class C Cephalosporinase and Carbapenemase-Producing Klebsiella Species Isolated from Patients Consulted at Four Yaounde-Based Hospitals.

Abstract

Background: Klebsiella spp. are bacteria of medical importance for their role in opportunistic infections. These infections are often difficult to treat because of acquired resistance to one or several families of antimicrobials. The present study aimed at detecting Extended Spectrum Beta-lactamase (ESBL), Class C cephalosporinase (AmpC) and carbapenemase resistant phenotypes of Klebsiella spp. isolated from patients consulted at four Yaounde-based hospitals. Results: The frequency of the species isolated was Klebsiella pneumoniae (69%), K. oxytoca (14%), K. ozaenae (12%) and K. rhinoscleromatis (5%). Isolates were most resistant to penicillins (90%), sulphonamides (84%), cepaholosporins (80%), and least resistant to carbapenems (10.2%). Three isolates namely: two K. oxytoca and one K. pneumoniae were resistant to all twenty-eight (28) antibiotics tested. Klebsiella pneumoniae was the species with the most multidrug resistant isolates (59.4%). Most isolates (83.6%) expressed at least one resistance phenotype, while 63.6% of the isolates expressed all three phenotypes. Many of the isolates were ESBL producers (71.6%), while fewer isolates were carbapenemase (26.7%) and AmpC (6.6%) producers. Three carbapenemases (Klebsiella pneumoniae carbapenemase-KPC, Metallo-Beta Lactamase-MBL and OXA-48) were detected from 26.7% of the isolates and the combination KPC and MBL were the most detected phenotypes (12.9%). Conclusion: These results reveal that resistance of Klebsiella spp. to cephalosporins is high and this may be exacerbated as a result of the co-expression of AmpC and carbapenemases. About a quarter of the isolates had acquired carbapenemases that confer resistance to all beta-lactamases and carbapenems which constitute last line drugs. The resistance burden is further strengthened in isolates that acquired more than one carbapenemase aggravating associated patient morbidity and mortality. Therefore, it is necessary to continue monitoring antimicrobial resistance of local strains for better informed decisions on empirical treatment guide and better patient care.