Characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolates from hospitals in KwaZulu-Natal (KZN) province, Republic of South Africa

Abstract

Epidemiological data based on phenotypic and molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) in sub-Saharan Africa are limited. This investigation studied 61 MRSA isolates obtained from 13 health care institutions in KwaZulu-Natal province (KZN), South Africa, from March 2001 to August 2003. More than 80% of the isolates were resistant to at least four classes of antibiotics and six isolates were resistant to the aminoglycoside, macrolide-lincosamide and tetracycline groups of antibiotics, heavy metals and nucleic acid binding compounds. Pulsed field gel electrophoresis (PFGE) of SmaI digested genomic DNA revealed seven types, designated A to G. Type A was the main pulsotype (62.3%) and identified in 11 of the 13 health care institutions, suggesting that it represented a major clone in health care institutions in KZN province, South Africa. Analysis of representative members of the three major pulsotypes by spa, multilocus sequence typing (MLST) and SCCmec typing revealed the types t064-ST1173-SCCmec IV and t064-ST1338-SCCmec IV (PFGE type A, single-locus and double-locus variants of ST8), t037-ST239-SCCmec III (PFGE type F) and t045-ST5-SCCmec III (PFGE type G). The combination of various typing methods provided useful information on the geographic dissemination of MRSA clones in health care institutions in KZN, South Africa. The observation of major clones circulating in health care facilities in KZN indicates that adequate infection control measures are urgently needed.