Assessment of different methods for the detection of biofilm production in coagulase-negative staphylococci isolated from blood cultures of newborns.

Autor:	Rampelotto RF; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil.; Programa de Pós-Graduação, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil., Lorenzoni VV; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil., Silva DDC; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil.; Programa de Pós-Graduação, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil., Coelho SS; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil., Wust V; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil., Garzon LR; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil., Nunes MS; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil.; Laboratório de Análises Clínicas, Hospital Universitário de Santa Maria, Santa Maria, RS, Brasil., Meneghetti B; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil.; Laboratório de Análises Clínicas, Hospital Universitário de Santa Maria, Santa Maria, RS, Brasil., Brites PC; Laboratório de Biologia Molecular, Hospital Universitário de Santa Maria, Santa Maria, RS, Brasil., Hörner M; Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil., Hörner R; Departamento de Análises Clínicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil.; Programa de Pós-Graduação, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil.
Jazyk:	angličtina
Zdroj:	Revista da Sociedade Brasileira de Medicina Tropical [Rev Soc Bras Med Trop] 2018 Nov-Dec; Vol. 51 (6), pp. 761-767.
DOI:	10.1590/0037-8682-0171-2018
Abstrakt:	Introduction: Coagulase-negative staphylococci (CoNS) are a frequent cause of bacteremia, especially in neonates. The major virulence determinant in CoNS is the ability to produce biofilms, which is conferred by the icaADBC genes. This study aimed to assess different methods for the detection of biofilm formation in 176 CoNS isolates from blood cultures of newborns. Methods: The presence of the icaACD genes was assessed by polymerase chain reaction (PCR), and biofilm formation was assessed on congo red agar (CRA), by the tube method (TM), and on tissue culture plates (TCP). Results: Of the 176 CoNS isolates, 30.1% expressed icaACD and 11.4% expressed icaAD. The CRA assay and TM showed that 42% and 38.6% of the isolates were biofilm producing, respectively. On TCP, 40.9% of the isolates produced biofilms; 21% were weakly adherent and 19.9% were strongly adherent. When compared to the gold standard technique (PCR), the CRAassay showed 79% sensitivity and 84% specificity (kappa = 0.64), TM showed 78% sensitivity and 89% specificity (kappa = 0.68), and TCP showed 99% sensitivity and 100% specificity (kappa = 0.99). Conclusions: In this study, ~42% of CoNS isolates produced biofilms, and the presence of icaACD was associated with a greater capacity to form biofilms. Compared to the other phenotypic methodologies, TCP is an ideal procedure for routine laboratory use.
Databáze:	MEDLINE
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