Virulence factors among Staphylococcus lugdunensis are associated with infection sites and clonal spread

• Published in: European journal of clinical microbiology & infectious diseases 2015-04, Vol.34 (4), p.773-778
• Main Authors: Giormezis, N., Kolonitsiou, F., Makri, A., Vogiatzi, A., Christofidou, M., Anastassiou, E. D., Spiliopoulou, I.
• Format: Article
• Language: English
• Subjects: Adult; Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Antibiotics; Antimicrobial agents; Biofilms; Biofilms - growth & development; Biomedical and Life Sciences; Biomedicine; Cluster Analysis; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Endocarditis; Female; Genes; Genetic diversity; Genetic Variation; Genotype; Greece; Hospitals; Humans; Infections; Internal Medicine; Male; Medical Microbiology; Microbial Sensitivity Tests; Molecular Typing; Pathogens; Peptides; Prostheses; Proteins; Slush; Staphylococcal Infections - microbiology; Staphylococcus lugdunensis; Staphylococcus lugdunensis - classification; Staphylococcus lugdunensis - genetics; Staphylococcus lugdunensis - isolation & purification; Staphylococcus lugdunensis - pathogenicity; Virulence; Virulence Factors - genetics
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-014-2291-8

Staphylococcus lugdunensis has emerged as a significant human pathogen, with distinct clinical and microbiological characteristics. Our goal was to identify the virulence factors in S. lugdunensis recovered from infected patients of two Greek hospitals during a six-year period (2008–2013). A collection of 38 S. lugdunensis was tested for biofilm formation, antimicrobial susceptibility, clonal distribution, virulence factors ( ica operon, fbl , atlL , vwbl , slush ) and antibiotic resistance genes ( mecA , ermC ) carriage. Strains were classified into pulsotypes by pulsed-field gel electrophoresis (PFGE) of Sma I DNA digests. The majority (22) was isolated from skin and soft tissue infections (SSTIs), nine from deep-sited infections (DSIs), including three bacteraemias and seven from prosthetic device-associated infections (PDAIs). All isolates were oxacillin-susceptible, mecA -negative and fbl -positive. The highest resistance rate was detected for ampicillin (50 %), followed by erythromycin and clindamycin (18.4 %). Fourteen isolates (36.8 %) produced biofilm, whereas 26/38 (68.4 %) carried the ica operon. Biofilm formation was more frequent in isolates from PDAIs. Thirty-six strains (94.7 %) carried atlL and 31 (81.6 %) carried vwbl , whereas slush was detected in 15 (39.5 %). PFGE revealed a low level of genetic diversity: strains were classified into seven pulsotypes, with two major clones (C: 22 and D: nine strains). Type C strains recovered from all infection sites prevailed in biofilm formation and ermC carriage, whereas type D strains associated with SSTIs and DSIs carried more frequently vwbl , slush or both genes. Despite susceptibility to antimicrobials, the clonal expansion and carriage of virulence factors, combined with biofilm-producing ability, render this species an important pathogen that should not be ignored.