Abstract

Staphylococcus lugdunensis is a member of the coagulase-negative staphylococci (CNS) which has clinical and laboratory characteristics that resemble those of Staphylococcus aureus. The purpose of this study was to investigate the frequencies, microbiological characteristics and antibiotic susceptibilities of S. lugdunensis isolates. Forty-one (41) S. lugdunensis  isolates, which were collected between 2006 and 2009 in our laboratory, were retrospectively included. Twenty-one (21) re-cultured isolates were investigated about several conventional biochemical tests and antibiotic susceptibility tests. The species identification was confirmed by 16S rRNA gene sequencing. Most of S. lugdunensis isolates (71%) were isolated from skin-soft tissue samples. Nine 9(43%) out of 21 isolates were clumping factor positive. All of the isolates were tube coagulase-negative, pyrrolidonyl arylamidase (PYR) and DNase positive. The ornithine decarboxylase (ODC) test, beta-hemolysis and synergistic hemolysis were positive in 19 (90%) isolates. Slime production was found in 5 (24%) isolates. Most isolates were susceptible to the antibiotics tested, although 14% were β-lactamase positive and could be identified by the disk diffusion method for penicillin G. Methicillin resistance and vancomycin tolerance did not detected. S. lugdunensis, is an unusual pathogen which may be can be misidentified with S. aureus by some laboratory characteristics, but which in many instances may be treated with narrow-spectrum antibiotics.

Key words: Staphylococcus lugdunensis, infection, characteristics, identification, susceptibility.