Unusually High Prevalence of Panton-Valentine Leukocidin Genes among Methicillin-Sensitive Staphylococcus aureus carried in the Indonesian Population

Department of Medical Microbiology and Infectious Diseases, Erasmus MC, University Medical Center Rotterdam, 's-Gravendijkwal 230, 3015 CE, Rotterdam, The Netherlands; Department of Clinical Microbiology, Dr. Kariadi Hospital – School of Medicine, Diponegoro University, Jl. Dr. Soetomo 16-18, Semarang 50231, Indonesia; Department of Clinical Microbiology, Dr. Soetomo Hospital – School of Medicine, Airlangga University, Jl. Prof. Dr. Moestopo 47, Surabaya 60131, Indonesia; Department of Bioinformatics, Erasmus MC, University Medical Center Rotterdam, Dr. Molewaterplein 42, 3015 GD, Rotterdam, The Netherlands; Department of Internal Medicine, Dr. Soetomo Hospital – School of Medicine, Airlangga University, Jl. Prof. Dr. Moestopo 47, Surabaya 60131, Indonesia; Department of Infectious Diseases, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands

^* To whom correspondence should be addressed. Email: j.severin{at}erasmusmc.nl.

	Abstract

Few data on the molecular characteristics and epidemiology of Staphylococcus aureus from Indonesia are available. The purpose of the present study was to define S. aureus reservoirs in both the Indonesian community and the hospital using a collection of 329 nasal carriage isolates obtained during a survey of 3,995 healthy individuals and patients from Java, Indonesia. Only one strain (0.3%) was identified as methicillin-resistant S. aureus (MRSA) by mecA gene PCR. The Panton-Valentine leukocidin (PVL) genes were detected in 35 methicillin-sensitive S. aureus (MSSA) strains (10.6%). Molecular typing by pulsed-field gel electrophoresis of the 329 isolates showed extensive genetic diversity among both PVL-positive and PVL-negative strains. In Surabaya, however, a cluster was identified that was strongly associated with the presence of the PVL locus (P < 0.0001). As determined by high-throughput amplified fragment length polymorphism (AFLP), PVL-positive strains occurred throughout all major AFLP clusters (I-IV). Multilocus sequence typing of a subset of isolates showed that most PVL-positive strains belonged to sequence type (ST) 188, while most PVL-negative isolates belonged to ST4The high prevalence of PVL-positive S. aureus strains in certain regions of Indonesia is of concern since these strains may cause severe infections in the community and in hospitals.