Extended Spectrum Beta-Lactamases in Clinical Isolates of Escherichia coli and Klebsiella pneumoniae from University of Uyo Teaching Hospital, Uyo-Nigeria

Aims: This study was aimed to investigate the prevalence of ESBL-producing Escherichia coli and Klebsiella pneumoniae in clinical samples from University of Uyo Teaching Hospital (UUTH), Uyo-Nigeria, and determine their antimicrobial susceptibility profile.

Study Design: This study involved sample collection and laboratory analysis of samples.

Place and Duration of Study: The study was conducted at the University of Uyo Teaching Hospital, Uyo between January and June 2013.

Methodology: Faecal, wound and urine samples were obtained from 280 in- and out-patients attending University of Uyo Teaching Hospital, Uyo. Escherichia coli and Klebsiella pneumoniae isolates were identified using standard conventional microbiological methods. Antimicrobial susceptibility assay was performed using the Kirby-Bauer disc diffusion method and test for ESBL production was conducted using the Double Disk Synergy Test (DDST) following the reviewed Clinical Laboratory Standards Institute (CLSI) guidelines.

Results: ESBL was detected in 40 (47.1%) of the 85 isolates and E. coli was the major ESBL producer, 21 (52.5%) followed by K. pneumoniae, 19 (47.5%). The detection rates of ESBL producing organisms was higher in female patients (57.5%) than their male counterparts (42.5%), and also high in infants under 1 year of age (20%). The ESBL-producers were most frequently detected in paediatric ward, 11 (27.5%); surgical ward, 10 (25.0%) and GOPD, 7 (17.5%). Majority of the isolates encountered were multidrug resistant strains. Tetracycline and trimethoprim/sulfamethoxazole were the least susceptible antimicrobials to E. coli and K. pneumoniae ranging from 14.6% - 24.3%, while less than 50% were ciprofloxacin sensitive. Carbapenems were the most effective antimicrobials. All isolates were susceptible to imipenem, while >90% of the isolates were susceptible to ertapenem.

Conclusion: This study reveals that there is a high prevalence of ESBL-producing organisms in clinical samples, especially isolates from infants, in UUTH, Uyo with attendant high multi-drug resistance to commonly used antimicrobials. There is need for increased ESBL surveillance as it poses serious threat to successful treatment of infections and exacerbates the problem of antimicrobial resistance especially with commonly used drugs in resource poor settings.