Prevalence and Genetic Characteristics of Staphylococcus aureus and Staphylococcus argenteus Isolates Harboring Panton-Valentine Leukocidin, Enterotoxins, and TSST-1 Genes from Food Handlers in Myanmar

Asymptomatic carriers of toxigenic <i>Staphylococcus aureus</i> are potential source of diseases, including food poisoning. Toxigenic potential and genetic traits of colonizing <i>S. aureus</i> were investigated for 563 healthy food handlers in Myanmar. Carriage of <i>S. aureus</i> was found in 110 individuals (19.5%), and a total of 144 <i>S. aureus</i> isolates were recovered from nasal cavities (110 isolates) and hands (34 isolates). Panton-Valentine leucocidin genes (<i>pvl</i>) were detected in 18 isolates (12.5%), among which 11 isolates were classified into <i>coa</i>-VIa, <i>agr</i> type III, and ST1930 (CC96) that had been also detected in <i>pvl</i>-positive clinical isolates in Myanmar. A <i>pvl</i>-positive, ST2250 nasal isolate was identified as <i>S. argenteus</i>, a novel coagulase-positive staphylococcus species. Toxic shock syndrome toxin-1 (TSST-1) gene was detected in five <i>pvl</i>-negative isolates. All of the 144 isolates harbored at least one of the 21 enterotoxin(-like) gene(s). The most prevalent enterotoxin(-like) gene was <i>selw</i> (98%), followed by <i>selx</i> (97%), <i>sei</i> (28%), <i>sely</i> (28%), <i>sem</i> (26%), <i>sel</i> (24%), and <i>sea</i> and <i>sec</i> (22% each). Considerable genetic diversity with five groups was detected for <i>selw</i>. The present study revealed the relatively high rate of <i>pvl</i>, as well as the wide distribution of enterotoxin(-like) genes among colonizing <i>S. aureus</i> in Myanmar.