caa a22 4500 606155317 CHVBK 20210128100603.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s10096-014-2197-5 doi (NATIONALLICENCE)springer-10.1007/s10096-014-2197-5 Colonisation and interaction between S. epidermidis and S. aureus in the nose and throat of healthy adolescents [Elektronische Daten] [E. Fredheim, T. Flægstad, F. Askarian, C. Klingenberg] Nasal colonisation with Staphylococcus aureus is a risk factor for developing nosocomial infections. It has been reported that S. epidermidis may produce a serine protease (Esp) inhibiting S. aureus biofilm formation and nasal colonisation. We aimed to analyse the correlation between S. aureus nasal and/or throat carriage and co-colonisation with S. epidermidis strains carrying esp, and the inhibitory effects of S. epidermidis culture supernatants on S. aureus biofilm formation and growth. We obtained 114 S. epidermidis isolates from the nose and 74 S. aureus from the nose and/or throat of healthy adolescents. S. aureus biofilm formation was analysed in a microtitre plate assay and the prevalence of ica, encoding biofilm formation, and esp was analysed with polymerase chain reaction (PCR). Inhibitory effects of S. epidermidis culture supernatants on S. aureus biofilm formation and growth was analysed in vitro. esp prevalence and expression was correlated with inhibitory effects. We detected biofilm formation in 45/74 (61%) S. aureus strains. The ica operon was more prevalent in isolates colonising the nose (12/15; 80%) versus isolates colonising the throat only (8/46; 17%). Almost two-thirds of S. epidermidis culture supernatants displayed high (≥50%) S. aureus biofilm inhibitory activity, without affecting growth. We found no correlation between the level of inhibitory activity and S. aureus colonisation. esp was ubiquitous in S. epidermidis, but esp expression did not correlate with biofilm inhibitory activity. S. epidermidis culture supernatants inhibit S. aureus biofilm formation, but do not affect bacterial growth. esp expression was not correlated with the inhibitory effects observed. Springer-Verlag Berlin Heidelberg, 2014 Fredheim E. Department of Paediatrics, University Hospital of North Norway, Tromsø, Norway aut Flægstad T. Department of Paediatrics, University Hospital of North Norway, Tromsø, Norway aut Askarian F. Research Group for Host-Microbe Interactions, Department of Medical Biology, University of Tromsø, Tromsø, Norway aut Klingenberg C. Department of Paediatrics, University Hospital of North Norway, Tromsø, Norway aut European Journal of Clinical Microbiology & Infectious Diseases Springer Berlin Heidelberg 34/1(2015-01-01), 123-129 0934-9723 34:1<123 2015 34 10096 https://doi.org/10.1007/s10096-014-2197-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10096-014-2197-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fredheim E. Department of Paediatrics, University Hospital of North Norway, Tromsø, Norway aut NATIONALLICENCE 700 1- Flægstad T. Department of Paediatrics, University Hospital of North Norway, Tromsø, Norway aut NATIONALLICENCE 700 1- Askarian F. Research Group for Host-Microbe Interactions, Department of Medical Biology, University of Tromsø, Tromsø, Norway aut NATIONALLICENCE 700 1- Klingenberg C. Department of Paediatrics, University Hospital of North Norway, Tromsø, Norway aut NATIONALLICENCE 773 0- European Journal of Clinical Microbiology & Infectious Diseases Springer Berlin Heidelberg 34/1(2015-01-01), 123-129 0934-9723 34:1<123 2015 34 10096