| Maryam Jamalan | 1 Article |
<sec>
<title>Objectives</title>
<p>Biofilm formation is one of the important features of <italic>Staphylococcus epidermidis</italic>, particularly in nosocomial infections. We aimed to investigate the biofilm production by phenotypic methods and the presence of <italic>ica</italic> genes in <italic>S epidermidis</italic>.</p></sec>
<sec>
<title>Methods</title>
<p>A total of 41 <italic>S epidermidis</italic> isolates were recovered from different clinical specimens. Biofilm formation was evaluated by microtiter plate, tube method and Congo red agar method. The presence of <italic>icaA</italic> and <italic>icaD</italic> genes was investigated by PCR. Validity of methods (sensitivity and specificity), and metrics for test performance (positive/negative predictive value, and positive/negative likelihood ratio) were determined.</p></sec>
<sec>
<title>Results</title>
<p>By both microtiter plate and tube method, 53.6% of <italic>S epidermidis</italic> isolates were able to produce biofilm, whilst only 24.4% of isolates provided a biofilm phenotype on Congo red agar plates. <italic>icaA</italic> and <italic>icaD</italic> genes were found in 100% and 95.1% of isolates, respectively. Biofilm phenotypes accounted for 4.8% by microtiter plate assay, despite the absence of the <italic>ica</italic> gene. Congo red agar and PCR exhibited a lower sensitivity (18% and 45.5%, respectively) for identifying the biofilm phenotype in comparison to microtiter plate.</p></sec>
<sec>
<title>Conclusion</title>
<p>The microtiter plate method remains generally a better tool to screen biofilm production in <italic>S epidermidis</italic>. In addition, the ability of <italic>S epidermidis</italic> to form biofilm is not always dependent on the presence of <italic>ica</italic> genes, highlighting the importance of <italic>ica</italic>-independent mechanisms of biofilm formation. The use of reliable methods to specifically detect biofilms can be helpful to treat the patients affected by such problematic bacteria.</p></sec>
Citations
Citations to this article as recorded by
|
|
