Volume No. 10 Issue No.: 2 Page No.: 271-276 October-December 2015




Keerthi S., Kumar Pradeep S. S., Raja K. and Nandkumar Maya A.*

Department of Microbial Technology, BMT wing, Sree Chitra Thirunal Institute of Medical Sciences Technology, Thiruvananthapuram, Kerala (INDIA)


Received on : June 10, 2015




Most chronic infectious which are recalcitrant to antibiotic therapy are due to bacterial biofilms. Studies have reported the presence of phenotypic variants within the biofilms, resistant to high concentration of antibiotics. Here, we aim at studying the influence of antibiotics on isolates of Pseudomonas. Pseudomonas is an opportunistic pathogen and causes infection ranging from acute to chronic in immune compromised, cystic fibrosis and also medical device related infections. Disc diffusion assay was performed to assess the antibiotic sensitivity of the isolates. Dynamics of biofilm formation was studied by crystal violet assay in the presence and absence of antibiotics to assay the biofilm forming ability of the isolates. Congo red binding assay was used to quantify the mucous producing ability of the isolates. Our results demonstrate : (1) biofilm forming ability of clinical isolates are escalated in presence of sub inhibitory concentration of antibiotics and (2) amongst the clinical strains the mucous producing strains produced biofilms that are more resistant to antimicrobials . In conclusion, we demonstrate the importance of biofilm formation in the clinical scenario as they are one of the prime reasons for antibiotic resistance and persistent infections.


Keywords : Pseudomonas, Dynamics, Biofilms, Antibiotic resistance, Mucous production