[Infection by Staphylococcus lugdunensis: clinico-microbiologic characterization of 25 cases]

S. lugdunensis is a recently described staphylococcal species with morphologic characteristic similar to those of S. aureus. It has been associated to a variety of clinical infections. In this paper we present the clinical and microbiological features of S. lugdunensis isolates from 25 patients.

We have studied the S. lugdunensis isolates obtained from clinical specimens in our laboratory over a three-year period, 1994-96. For all isolates we determined the presence of clumping factor, Dnase, free coagulase in tube and ornithine decarboxylase (ODC). Full identification was performed with API ID32-Staph strips (bioMérieux) and antimicrobial susceptibility with commercial broth microdilution MIC panels (PASCO System, Difco).

We obtained 38 S. lugdunensis isolates from 25 patients. The clinical specimens were: breast exudate/pus (8), blood (5), surgical wound (2), urine (2), nasal exudate (2), peritoneal fluid (1), pleural fluid (1), venous catheter (1), Tenckoff catheter (1), bartholin pus (1), ulcer (1). The isolates were considered clinically significant in 20 patients, whereas those of the remaining 5 patients were considered mere colonizers. All isolates were clumping factor (+), ODC (+), Dnase (-) and free coagulase (-). 16/23 (69.5%) were susceptible to penicillin and only one isolate was methicillin-resistant.

We have isolated S. lugdunensis from a great variety of clinical specimens (blood, sterile body fluids, urine, skin, abscesses and nasal mucosa). It is specially remarkable the association with non-puerperal mastitis. The presence of clumping factor in all isolates can easily lead to misidentification as S. aureus. The ODC test appears as a good screening method for detecting S. lugdunensis. S. lugdunensis shows a good susceptibility to betalactamic an other antimicrobial agents.