European Journal of Biomedical and Pharmaceutical Sciences

COMPARISON OF QUALITATIVE AND QUANTITATIVE TECHNIQUES OF BIOFILM PRODUCTION IN STAPHYLOCOCCUS EPIDERMIDIS

Riyaz Sheriff*, Sheena A. and Radha Madhavan

ABSTRACT

Staphylococcus epidermidis with its non fastidious nature has evolved as successful pathogen causing wide variety of infections. One of the main virulence determinants of Staphylococcus epidermidis is biofilm formation which helps escape the immune assault and antibiotics. The estimation of biofilm formation will help differentiate between commensal and pathogenic S.epidermidis. Aim & Objective: To determine clinically significant Staphylococcus epidermidis and to ascertain their virulence using qualitative and quantitative methods of biofilm detection. Methodology 76 clinically significant isolates were segregated into two groups - Isolates with definite clinical significance (Group A - 46isolates) and Isolates with doubtful significance (Group B – 30isolates).Two qualitative methods Congo red agar method, Tube method were employed. Quantitative detection of biofilm (adherence) was detected by Microtitre plate method. Results: The more sensitive and quantitative method was microtitre plate method. In group A 21 were moderate biofilm producers and 14 were strong biofilm producers. In group B 8 out of 30 were moderate biofilm producers and 6 were strong biofilm producers. The comparison methods showed that microtitre plate method was more sensitive in detecting of biofilm and helps in quantitative assessment of biofilm formation. Difference between Group A and Group B isolates was statistically significant, p value being <0.004. Discussion: These methods are cost effective and need minimal technical training. Identifying Biofilm will help differentiate pathogenic and commensal CONS. The reporting of Biofilm will help the clinician plan appropriate line of therapy.

Keywords: CONS, Biofilm, Congo red agar, Staphylococcus epidermidis.