Lack of Direct Correlation between Biofilm Formation and Antimicrobial Resistance in Clinical Staphylococcus epidermidis Isolates from an Italian Hospital

Microorganisms

Jari Intra¹  Matteo Brilli²  Elio Rossi²  Moira Paroni²  Gianmarco Conte²  Paolo Landini²  Gabriella Leccese²  Massimo Moreo³  Simona Sabella³  Davide Carcione⁴  Alice Bonomi⁵ 

[1] Clinical Chemistry Laboratory, University of Milano-Bicocca, Azienda Socio Sanitaria Territoriale di Monza ASST-Monza, San Gerardo Hospital, Via Pergolesi 33, 20900 Monza, Italy;Department of Bioscience, University of Milan, 20133 Milan, Italy;Department of Laboratory Medicine, IRCCS Centro Cardiologico Monzino, 20138 Milan, Italy;Laboratory of Microbiology and Virology, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy;Unit of Biostatistics, IRCCS Centro Cardiologico Monzino, 20138 Milan, Italy;

关键词: Staphylococcus epidermidis;    biofilm;    crystal violet;    antibiotic resistance polysaccharide intercellular adhesin (PIA);    Congo red agar;   

DOI  :  10.3390/microorganisms10061163

来源: DOAJ

【 摘 要 】

Staphylococcus epidermidis is an opportunistic pathogen and a frequent cause of nosocomial infections. In this work, we show that, among 51 S. epidermidis isolates from an Italian hospital, only a minority displayed biofilm formation, regardless of their isolation source (peripheral blood, catheter, or skin wounds); however, among the biofilm-producing isolates, those from catheters were the most efficient in biofilm formation. Interestingly, most isolates including strong biofilm producers displayed production levels of PIA (polysaccharide intercellular adhesin), the main S. epidermidis extracellular polysaccharide, similar to reference S. epidermidis strains classified as non-biofilm formers, and much lower than those classified as intermediate or high biofilm formers, possibly suggesting that high levels of PIA production do not confer a particular advantage for clinical isolates. Finally, while for the reference S. epidermidis strains the biofilm production clearly correlated with the decreased sensitivity to antibiotics, in particular, protein synthesis inhibitors, in our clinical isolates, such positive correlation was limited to tetracycline. In contrast, we observed an inverse correlation between biofilm formation and the minimal inhibitory concentrations for levofloxacin and teicoplanin. In addition, in growth conditions favoring PIA production, the biofilm-forming isolates showed increased sensitivity to daptomycin, clindamycin, and erythromycin, with increased tolerance to the trimethoprim/sulfamethoxazole association. The lack of direct correlation between the biofilm production and increased tolerance to antibiotics in S. epidermidis isolates from a clinical setting would suggest, at least for some antimicrobials, the possible existence of a trade-off between the production of biofilm determinants and antibiotic resistance.

【 授权许可】

Unknown