Summer Research Fellowship Programme of India's Science Academies


N Ramya

Sri Bhuvanendra College, Karkala 574122

Prof. Sarita G. Bhat

Department of Biotechnology CUSAT, Cochin, Kerala 682022


Most of the nosocomial infections are associated with the implantation of biomedical devices. Catheter Associated Urinary Tract Infections (CAUTI) are one of the most common causes of nosocomial infections. These infections are associated with the long term use of urinary catheters. Urinary catheters are used by a large number of people to deal with urinary retention and involuntary urination. Despite the benefits brought by their use, they provide a suitable surface for colonization of microorganisms leading to the formation of a biofilm, causing urinary tract infections which put the patient's health at risk. A biofilm is defined as a microbiologically derived sessile community characterized by bacteria that irreversibly adhere to each other or to a surface. This surface may be inert, non living material or living tissue. These microorgaisms are embedded in a self-produced matrix of extra cellular polymeric substances (EPS). The EPS matrix acts as a barrier for antibiotics reaching the bacteria. Bacteria in biofilm shows more resistance to antibiotics. The most common organisms which commonly contaminate urinary catheters and develop biofilms are Escherichia coli , Pseudomonas aeruginosa, Enterococcus, Proteus mirabilis and Klebsiella pneumoniae. The present study aims to characterize the seven strong biofilm producing bacteria isolated from urinary catheters- BTTLA2, BTTLB6, BTTDC5, BTTDD3, BTTDD4, BTTDD5, BTTDD6. Seven strong biofilm producing isolates were characterized based on their biochemical characteristics outlined in Bergey's Manual of Systematic Bacteriology. The bacterial isolates were gram stained to determine their Gram nature, IMViC and various sugar utilization tests were carried out using HiIMViC Biochemical tests kit, (Himedia, India). Following biochemical characterization, all isolates will be subjected to antibiotic sensitivity assays using modified Kirby-Bauer disc diffusion method. Auto aggregation ability and surface hydrophobicity of the isolates will be investigated.This phenotypic characterization can yield more direct functional information that reveals what metabolic activities are taking place to aid the survival, growth and development of the bacteria. These may be embodied, for example, in a microbe's adaptive ability to grow on a certain substrate or in the degree to which it is resistant to a cohort of antibiotics.

Keywords: Biofilm, Urinary tract infections, Urinary catheters

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