Abstract:
BACKGROUND : Klebsiella pneumoniae is an opportunistic pathogen often associated with nosocomial infections. A suspected outbreak of
K. pneumoniae isolates, exhibiting reduced susceptibility to carbapenem antibiotics, was detected during the month of May 2012 among
patients admitted to a haematology unit of a tertiary academic hospital in Cape Town, South Africa (SA).
OBJECTIVES : An investigation was done to determine possible epidemiological links between the case patients and to describe the mechanisms
of carbapenem resistance of these bacterial isolates.
Methods. Relevant demographic, clinical and laboratory information was extracted from hospital records and an observational review of
infection prevention and control practices in the affected unit was performed. Antimicrobial susceptibility testing including phenotypic
testing and genotypic detection of the most commonly described carbapenemase genes was done. The phylogenetic relationship of all isolates
containing the blaOXA-181 carbapenemase gene was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing.
Results. Polymerase chain reaction analysis identified a total of seven blaOXA-181-positive, carbapenem-resistant K. pneumoniae isolates
obtained from seven patients, all from a single unit. These isolates were indistinguishable using PFGE analysis and belonged to sequence
type ST-14. No other carbapenemase enzymes were detected.
CONCLUSION : This is the first documented laboratory-confirmed outbreak of OXA-181-producing K. pneumoniae in SA, and highlights
the importance of enforcing strict adherence to infection control procedures and the need for ongoing surveillance of antibiotic-resistant
pathogens in local hospitals.
