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Molecular characterisation and epidemiological investigation of an outbreak of blaOXA-181 carbapenemase-producing isolates of Klebsiella pneumoniae in South Africa

Rachael Kiera Jacobson, Mohnamed Riyadh Manesen, Clinton Moodley, Mariette Smith, Seymour Williams, Mark Nicol, Colleen Bamford

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.


Authors' affiliations

Rachael Kiera Jacobson, 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

Mohnamed Riyadh Manesen, South African Field Epidemiology Training Programme, National Institute for Communicable Diseases, Sandringham, Johannesburg, South Africa; School of Health Systems and Public Health, University of Pretoria, South Africa; Centers for Disease Control and Prevention, Atlanta, Georgia, USA

Clinton Moodley, 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

Mariette Smith, Centre for Opportunistic, Tropical and Hospital Infections, National Institute for Communicable Diseases, Groote Schuur Hospital, Cape Town, South Africa

Seymour Williams, South African Field Epidemiology Training Programme, National Institute for Communicable Diseases, Sandringham, Johannesburg, South Africa; Centers for Disease Control and Prevention, Atlanta, Georgia, USA

Mark Nicol, 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

Colleen Bamford, 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

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Keywords

Epidemiology; Antibiotic resistance; Klebsiella

Cite this article

South African Medical Journal 2015;105(12):1030-1035. DOI:10.7196/SAMJ.2015.v105i12.9926

Article History

Date submitted: 2015-08-04
Date published: 2015-11-08

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