Abstract:
BACKGROUND. The increasing rates of antimicrobial resistance observed in the nosocomial pathogen Klebsiella pneumoniae are of major
public health concern worldwide.
Objectives. To describe the antibiotic susceptibility profiles of K. pneumoniae isolates from bacteraemic patients submitted by sentinel
laboratories in five regions of South Africa from mid-2010 to mid-2012. Molecular methods were used to detect the most commonly found
extended-spectrum beta-lactamase (ESBL) and carbapenemase resistance genes.
METHODS. Thirteen academic centres serving the public healthcare sector in Gauteng, KwaZulu-Natal, Free State, Limpopo and Western
Cape provinces submitted K. pneumoniae isolates from patients with bloodstream infections. Vitek 2 and MicroScan instruments were used
for organism identification and susceptibility testing. Multiplex polymerase chain reactions (PCRs) were used to detect blaCTX-M, blaSHV and
blaTEM genes in a proportion of the ESBL isolates. All isolates exhibiting reduced susceptibility to carbapenems were PCR tested for blaKPC
and blaNDM-1 resistance genes.
RESULTS. Overall, 68.3% of the 2 774 isolates were ESBL-positive, showing resistance to cefotaxime, ceftazidime and cefepime. Furthermore,
46.5% of all isolates were resistant to ciprofloxacin and 33.1% to piperacillin-tazobactam. The major ESBL genes were abundantly present
in the sample analysed. Most isolates (95.5%) were susceptible to the carbapenems tested, and no isolates were positive for blaKPC or blaNDM-1.
There was a trend towards a decrease in susceptibility to most antibiotics.
CONCLUSION. The high proportion of ESBL-producing K. pneumoniae isolates observed, and the prevalence of ESBL genes, are of great
concern. Our findings represent a baseline for further surveillance in SA, and can be used for policy and treatment decisions.
