2. Department of Medical Microbiology, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
Background: Extended-Spectrum β-Lactamase (ESBL) producing Enterobacteriaceae have become widespread in hospitals and are increasing in community settings where they cause a variety of infections. In addition to hydrolyzing most beta-lactam agents, bacteria harboring these enzymes display resistance to other unrelated antimicrobial agents and thus often pose a therapeutic dilemma. Though these resistance patterns have been studied elsewhere within Africa, such data from hospitals in Kenya are scanty. We therefore undertook to determine these patterns at the Aga Khan University hospital by studying multidrug resistant Escherichia coli and Klebsiella pneumoniae isolates from patients' samples.
Findings: A total of 159 isolates (109 E. coli and 50 K. pneumoniae) were confirmed as ESBL producers and tested against eighteen antimicrobials. The proportion of resistant isolates was high (>80%) for the antimicrobials tested with the exception of the carbapenems (<1%), nitrofurantoin (23%) and gentamicin (63%). Klebsiella pneumoniae had a higher proportion of isolates resistant to ceftazidime, gentamicin and nitrofurantoin (P < 0.05) than E. coli which had a higher proportion of isolates resistant to ciprofloxacin, levofloxacin and tetracycline (P < 0.05).
Conclusions: In our study, antimicrobial coresistance is common in ESBL producers; however resistance to carbapenems is low and these drugs would be the appropriate empiric therapy for serious or life threatening systemic infections. Nitrofurantoin retains good activity among the multidrug resistant isolates and can be the drug of choice for non-complicated urinary tract infections due to ESBL producing E. coli.
Keywords: Extended-spectrum beta lactamases, Escherichia coli, Klebsiella pneumoniae, antimicrobial susceptibility, empiric therapy