Premium
A combination of methods to evaluate biofilm production may help to determine the clinical relevance of Staphylococcus in blood cultures
Author(s) -
Iorio Natalia Lopes Pontes,
Lopes Ana Paula da Cruz Neves,
Schuenck Ricardo Pinto,
Barcellos Ariane Guimarães,
Olendzki André Nogueira,
Lopez Guillermo Lopez,
dos Santos Kátia Regietto
Publication year - 2011
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.2010.00288.x
Subject(s) - microbiology and biotechnology , biology , staphylococcus epidermidis , staphylococcus aureus , biofilm , bacteremia , coagulase , staphylococcal infections , staphylococcus , micrococcaceae , agar , agar plate , pathogen , staphylococcus haemolyticus , bacteria , antibiotics , antibacterial agent , genetics
Staphylococcus is the most prevalent pathogen causing bacteremia and many of its isolates possess the ability to form biofilm. In this study Staphylococcus isolates from the blood of patients with bacteremia were analyzed by two biofilm detection phenotypic methods: Congo red agar (CRA) and microtiter‐plate adherence (MPA) in relation to the presence of ica genes, detected by PCR. Their oxacillin susceptibility was also evaluated. Among 127 isolates evaluated, 47 were S. aureus and 80 were coagulase negative staphylococci (CNS). Seventy‐four (58.3%) isolates were mecA gene positive (27.7% S. aureus and 76.3% CNS isolates). Among the 40 S. aureus isolates which were positive for the ica genes, 25 (62.5%) were positive in MPA and 27 (67.5%) in CRA, whereas both methods combined detected 34 (85%) isolates as biofilm producers. Among 12 S. epidermidis isolates carrying ica genes, 8 were positive in MPA and 5 in CRA. The combination of CRA and MPA methods provided a better prediction of the presence of ica genes in S. aureus isolates than did either method alone.