Incidence of carbapenemase production among antibiotic resistant <i>Klebsiella</i> isolates in Zaria, Nigeria

Abstract

Carbapenemases are diverse group of Beta lactamases produce by Gram negative rods. These groups of enzymes are indicated in resistance to Beta lactam antibiotics that used to be drug of last resort in the control of infectious diseases. Incidence of Gram negative organisms producing these groups of enzymes may be a threat to management of infectious diseases in a developing country like Nigeria. In this study, incidence of Carbanemase production among antibiotic resistant Klebsiella species isolated from clinical samples of four hospitals in Zaria, Kaduna state, Nigeria, were analyzed. Conventionally identified Klebsiella isolates from the Hospitals were collected and characterized by standard microbiological methods to different species. Antibiotics susceptibility testing using Kirby Bauer agar diffusion method was conducted on the isolates. Isolates found resistant to Meropenem and/or Imipenem were tested for carbapenemase production using modified Hodges test (MHT). A total of 164 clinical isolates of suspected Klebsiella species were collected from the four hospitals under the study. The isolates generally came from urine (35.4%), sputum (26.2%), ear swab (17.1%), wound swab (13.4%) and vaginal swab (7.9%). Based on morphological and biochemical characterization, 130 of the isolates were identified as Klebsiella species. Further characterization and identification using Microgen identification kit, confirmed Klebsiella oxytoca (14.0%), Klebsiella pneumoniae (12.8%), Klebsiella ozaenae (1.2%), while 72% were other members of enterobacteriaceae. Antibiotic susceptibility testing of Klebsiella confirmed isolates showed resistance to Ceftriaxone (89.1%), Cefixime (82.6%), Amoxicillin/clavulanic acid (50%), Meropenem (37.0%), Cefoxitin (34.8%), Gentamicin (24.1%), Ofloxacin (23.9%) and Imipenem (10.9%).Out of 17(37.0%) isolates resistant to Meropenem, 14 (30.4%) were Klebsiella pneumoniae, while 2(4.3%) were Klebsiella oxytoca. Eleven (11) (23.9%) Klebsiella pneumoniae produced Carbapenemases. The findings showed that there is incidence of Carbapenemase production among Klebsiellai solates from some hospitals in Zaria, Nigeria.

Keywords: Carbapenemases, Antibiotics, Klebsiella isolates, susceptibility