Biofilm production in Gram-positive isolates causing urinary tract infection in a tertiary care hospital.

Abstract

Sir, Biofilm production by uropathogens may promote colonization leading to recurrent and multi drug resistant urinary tract infection (UTI).Owing to high-level natural resistance to current antibiotics infections caused by Staphylococcus epidermidis, Staphylococcus aureus and the enterococci, are difficult to treat. Furthermore, these organisms become resistant to the highest deliverable levels of antibiotics when growing in a biofilm. It is estimated that 60% of nosocomial infections are derived from biofilm-related infections, many of which are caused by coagulase-negative staphylococci (CONS). [1] Enterococcal UTIs occur primarily in older man, particularly in association with urinary tract manipulation or instrumentation or prostatic hypertrophy. [2] S. epidermidis, which is a common urinary isolate hospitalized patients older than 50 years of age is associated with UTI in about 20% of cases. [2] Staphylococcus saprophyticus accounts for 10-15% of acute symptomatic UTIs in young female patients. Isolation of S. aureus from the urine is very often related bacteremia infection of the kidney. [3] Unfortunately in current literature studies on biofilm formation in Enterococcus spp (which is a very important cause of UTI) and by other UTI causing Gram-positive cocci (GPC) are scarce. Hence, the present study was prospectively carried out to investigate the biofilm production by UTI causing GPC. A total of 35 non-repetitive clinical isolates (26 of S. aureus; 4 of CONS; 4 of Enterococcus faecalis and 1 of E. faecium) isolated from cases of UTIs, were prospectively investigated for biofilm production. The isolates were identified by standard microbiological techniques. All the isolates were then screened for biofilm production by using tissue culture plate (TCP), [4] tube