Detection of biofilm formation in urinary isolates: need of the hour
Abstract
The purpose of the study was to estimate biofilm (BF) formation in urinary catheterized patients, by comparing three methods i.e. Tissue culture plate method (TCP), Congo Red Agar method (CRM) and Tube method (TM) and to study the antimicrobial resistance pattern in BF producing and non BF producing isolates. A total of 130 urinary catheterized patients were taken as the study group. From one milli litre of urine sample isolates > 102 colony forming units per milli litre were screened for the detection of BF by TCP, TM and CRM. Antibiotic sensitivity test for both BF producing and non BF producing bacterial and fungal isolates were done as per CLSI guidelines. From 130 urine samples in our study group, 55 samples grew microorganisms of significance, of which 11 samples were poly-microbial in nature. Of these biofilm production was seen in 49 microorganisms (89.09%) by any of the three methods used. TCP method picked up 69% of biofilm producers as compared to TM and CRM which picked up only 36% and 27% biofilm producers respectively. Our study reveals TCP method as the more dependable one as compared to TM and CRA methods for the quantitative biofilm detection, so it can be recommended as a screening method in laboratories.
References
Christensen GD, Simpson WA, Bisno AL and Beachey EH. 1982. Adherence of slime-producing strains of Staphylococcus epidermidis to smooth surfaces. Infect Immun. 37(1): 318-26.
Christensen GD, Simpson WA, Younger JJ, Baddour LM, Barrett FF, Melton DM and Beachey EH. 1985. Adherence of coagulase negative Staphylococci to plastic tissue cultures: a quantitative model for the adherence of Staphylococci to medical devices. J Clin Microbiol., 22(6): 996-1006.
CLSI. 2006. Performance standards for antimicrobial susceptibility testing, Sixteenth information supplement. CLSI document M-100-S16 (M7). Wayne PA: Clinical and Laboratory Standards Institute. 26(3)
CLSI. 2008. Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts. Approved Standard, 3rd edn. CLSI document M27-A3. Villanova, PA: Clinical and Laboratory Standards Institute.
Costerton JW, Lewandowski Z, Caldwell DE, Korber DR and Lappin-Scott HM. 1995. Microbial Biofilms. Annu Rev Microbiol., 49: 711-745.
Donlan RM. 2001. Biofilm formation: A clinically relevant microbiological process. Clin Infect Disease. 33(8): 1387-1392.
Douglas LJ. 2003. Candida biofilms and their role in infection. Trends Microbiol., 11(1): 30-36.
Freeman DJ, Falkiner FR and Keane CT. 1989. New method for detecting slime production by coagulase negative staphylococci. J Clin Pathol., 42(8):872-874.
Hassan A, Usman J, Kaleem F, Omair M, Khalid A and Iqbal M. 2011. Evaluation of different detection methods of biofilm formation in the clinical isolates. Braz J Infect Dis., 15(4):305-311.
Mah TF and O’Toole GA. 2001. Mechanisms of biofilm resistance to antimicrobial agents. Trends Microbiol., 9(1): 34-39.
Mathur T, Singhal S, Khan S, Upadhyay DJ, Fatma T and Rattan A. 2006. Detection of biofilm formation among the clinical isolates of staphylococci: An evaluation of three different screening methods. Indian J Med Microbiol., 24(1):25-29.
Ruzicka F, Hola V, Votava M, Tejkalová R, Horvát R, Heroldová M and Woznicová V. 2004. Biofilm detection and clinical significance of Staphylococcus epidermidis isolates. Folia Microbiol (Praha). 49(5): 596-600.
Stepanovic S, Vukovi D, Hola V. Bonaventura GD, Djukić S, Ćirković I and Ruzicka F. 2007. Quantification of biofilm in microtitre plates: overview of testing conditions and practical recommendations for assessment of biofilm production by Staphylococci. APMIS. 115(8): 891-899.
Stewart PS and Costerton JW. 2001. Antibiotic resistance of bacteria in biofilms. Lancet. 358(9276): 135-138.
Winn W, Allen S, Janda W, Koneman E, Procop G, Schreckenberger P and Woods G. 2006. Editors Koneman's Color Atlas and Textbook of Diagnostic Microbiology. 6 th ed. Philadelphia: Lippincott Williams and Wilkins.
