ESBL-producing Enterobacteriaceae

Background: Resistance to extended-spectrum cephalosporins among Enterobacteriaceae has been reported yet

they serve as the last line treatment for severe infections in Uganda and other countries. This resistance often leads

to nosocomial infection outbreaks and therapeutic failures from multidrug resistant bacteria. The main objective of

this study was to determine the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae

in clinical samples of patients in various wards of Mulago Hospital; Uganda’s main national referral and teaching hospital.

Methods: This cross-sectional study was conducted between January-April, 2014. Purposive consecutive sampling was

used to collect pus swab, urine, blood and CSF samples from patients in the various wards. A total of 245 consecutive,

non-repetitive, clinical samples were obtained and tested for phenotypic ESBL production using the Double Disc

Synergy Test using cefotaxime, ceftazidime, cefotaxime-clavulanic acid and ceftazidime-clavulanic acid.

Results: Results show that 47 % of the 245 samples had Enterobacteriaceae isolates. Of these isolates 62 % were ESBL

producers while 38 % were of non-ESBL phenotype. E. coli was the most isolated organism (53.9 %), followed by K.

pneumoniae (28.7 %). Majority of Enterobacteriaceae organisms were isolated from urine samples, followed by pus

samples and of these 64.9 % and 47.4 % were ESBL-producers respectively. Klebsiella pneumoniae had the highest

percentage of ESBL producers (72.7 %). There was a higher percentage of isolates showing resistance to ceftazidime

(73 %) compared to cefotaxime (57.5 %). All Enterobacter cloacae isolates showed resistance to ceftazidime. There

were no statistically significant association between phenotype (ESBL/non-ESBL) and patients’ age or gender or

Enterobacteriaceae spp.

Conclusions: This study reveals a high prevalence of ESBL producing organisms in Mulago Hospital and high levels of

resistance to third generation cephalosporins. In addition to undertaking appropriate infection control measures, there

is urgent need for formulation of an antibiotic policy in Uganda to prevent spread of these organisms. This also calls for

continuous monitoring and reporting of the presence of such organisms in order to ensure rational and judicious use

of antibiotics by clinicians.

Keywords: ESBL, Enterobacteriaceae, Cefotaxime, Ceftazidime, Clavulanic acid