Antimicrobial susceptibility patterns of Escherichia coli strains isolated from urine samples in South Africa from 2007-2011

Abstract

Escherichia coli is the most common cause of urinary tract infections. Knowledge of its local antimicrobial susceptibility patterns can be used to inform choice of empiric antimicrobial therapy. In this article, we review data on antimicrobial susceptibility patterns of E. coli isolated from unselected urine specimens, in both the private and public sectors of South Africa from 2007-2011. Between 65 000-84 000 E. coli urinary isolates were reported annually from 19 laboratories located across South Africa. Susceptibility to fuoroquinolone and beta-lactam antibiotics decreased signifcantly and steadily in both private and public sectors over the fve-year period, although laboratory-based surveillance data may underestimate susceptibility rates due to selection bias and lack of differentiation between community- and hospital-acquired infections. Our data suggest that fuoroquinolones, co-amoxiclav and frst- and second-generation cephalosporins can still be used for empiric treatment in many local settings, but clinicians should be alert to the risk of treatment failure. With the withdrawal of nitrofurantoin from the local market, other oral antibiotic options are limited, and fosfomcyin may become increasingly important. Given their sustained high susceptibility rates, aminoglycosides should be considered to treat pyelonephritis more often. Judicious use of laboratory testing is advised and further research and surveillance is warranted.