title: Molecular characterisation and epidemiological investigation of an outbreak of blaOXA-181 carbapenemase-producing isolates of Klebsiella pneumoniae in South Africa.
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).
  
  
  OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Groote Schuur Hospital, Cape Town, South Africa; National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa; Division of Medical Microbiology, University of Cape Town, South Africa. rachaeljacobson@gmail.com.
authors.forename: Rachael Kiera
authors.initials: RK
authors.lastname: Jacobson
authors.forename: Mohnamed Riyadh
authors.initials: MR
authors.lastname: Manesen
authors.forename: Clinton
authors.initials: C
authors.lastname: Moodley
authors.forename: Mariette
authors.initials: M
authors.lastname: Smith
authors.forename: Seymour G
authors.initials: SG
authors.lastname: Williams
authors.forename: Mark P
authors.initials: MP
authors.lastname: Nicol
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Bamford
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D015780:Carbapenems / Q000494:pharmacology*; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification*; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D013019:South Africa; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D001618:beta-Lactamases; C063912:carbapenemase