Prevalence, identification, and antimicrobial susceptibility of Staphylococcus lugdunensis from various clinical specimens in Korea.

Staphylococcus lugdunensis is an unusually virulent coagulase-negative staphylococcus (CoNS) that can cause many types of infection. All culture specimens were collected from patients at Inje University Busan Paik Hospital between October 2005 and March 2006. S. lugdunensis was identified using the phenotypic biochemical tests and 16S rDNA sequencing. Among 358 CoNS, three strains were identified as S. lugdunensis. All three isolates showed positive results in the clumping factor testing, but the L-pyrrolidonyl-beta-naphthylamide hydrolysis test was positive in only one and the ornithine decarboxylase test in two. Two of the three isolates were correctly identified by API Staph, but none of them was identified correctly by the Vitek I system. All three strains were penicillin resistant secondary to beta-lactamase production. S. lugdunensis was an unrecognized but infrequent cause of infection.