Occurrence of extended spectrum beta-lactamase enzymes in clinical isolates of Klebsiella species from Harar region, eastern Ethiopia.

Extended Spectrum beta-Lactamases (ESBLs) producer and multidrug resistant Klebsiella spp. are becoming a major nosocomial pathogen globally. There are no documented reports yet on the occurrence of ESBL enzymes in Klebsiella spp. species from Ethiopia. This study was undertaken to isolate and determine the occurrence of ESBLs and multi-drug resistant Klebsiella spp. in different clinical samples obtained from patients. A cross-sectional survey was conducted in four different hospitals of Harar region (Hiwot Fana, Misrak-Arbegnoch, Police and Army) from December 2003 to February 2004. Three hundred and eighty four clinical specimens (202 sputum, 164 urine and 18 pus) were collected from patients admitted in different wards. Antimicrobial susceptibilities were performed on 57 clinical isolates by standard disk diffusion procedures against eight antimicrobial agents. The ESBLs detection was made by using cefotaxime and ceftazidime alone and in combination with clavulanate. A total of 57 (15%) Klebsiella spp. were isolated from 384 patients. Of the 57 isolates, 33 (58%) were from sputum, 18 (31.5%) from urine and 6 (10.5%) from pus. Of the 57 Klebsiella spp., 54 (94.7%) were identified as K. pneumoniae and 3 (5.3%) as K. oxytoca. Resistance was found against cephalosporins [cefotaxime (39.0%), cefoxitin (39.0%), ceftazidime (40.0%), ceftriaxone (40.0%), cephalothin (42.0%)], chloramphenicol (70.0%), gentamicin (61.0%) and trimethoprim-sulphamethoxazole (65.0%). Analyzed Klebsiella isolates were characterized also by a high degree of multi-resistance (67.0%). In 19/57 (33.3%) of the Klebsiella isolates, ESBL production was detected. Rates of detection of ESBL producers were 42.1, 26.3, 26.3 and 5.3% in Hiwot-Fana, Misrak-Arbegnoch, Police and Army hospitals, respectively. Multi-drug resistant isolates were more prevalent among the ESBLs producers (95.0%) than non-producers (53.0%) (p=0.24). In conclusion, our results show that awareness of ESBL production by Klebsiella spp. is clinically important. In the absence of infection control measures, ESBL producing organisms readily pass horizontally from patient to patient. These strains also transiently colonize the hands of hospital staff members, thereby facilitating patient-to-patient transmission of the organism.