Original Research Article
Year: 2017 | Month: April | Volume: 7 | Issue: 4 | Pages: 107-112
Study of Biofilm Formation and Antibiotic Resistance in Urinary Isolates at a Tertiary Care Hospital in South India
Dr Parag Hawaldar1, Dr Kavita G Patil2, Dr Shankar G Karadesai3
1Associate Professor, Dept of Surgery Prakash Institute of Medical Sciences & Research, Urun, Islampur Dist Sangli, Maharashtra, India
2Professor, Dept of Microbiology Prakash Institute of Medical Sciences & Research, Urun, Islampur Dist Sangli, Maharashtra, India
3Professor, Dept of Microbiology J.N Medical College, Belgaum, Karnataka
Corresponding Author: Dr Kavita G Patil
Introduction: Bacteria adhere to the surfaces, initially in a reversible association and then through irreversible attachment, and eventually develop into an adherent biofilm of highly structured and cooperative consortia. Bacteria have been shown to form intracellular bacterial communities with many biofilm like properties within the bladder epithelium. Antibiotic treatment removes the planktonic bacteria only to have the symptoms return as a result of regrowth of the planktonic population from a nidus of infection consisting of biofilm bacteria displaying a higher level of resistance to the antibiotic. Biofilm infections in urogenital tissue are associated with significant morbidity and mortality.
Materials and Methods: A total of 250 midstream urine samples from symptomatic patients were collected aseptically. The samples were cultured on MacConkey agar and incubated at 37⁰C for 24 hrs. Urine culture yielding colony counts of>10⁵organisms/ml, along with >10pus cells/HPF of a centrifuged urine sample were interpreted as diagnostic of bacteriuria. Identification of isolates was performed by colony morphology, gram staining and standard biochemical tests. Antibiotic sensitivity testing against commonly used antibiotics was done by Kirby Bauer disc diffusion method. Extended spectrum Beta lactamase (ESBL) producers were detected by disc potentiation method. Detection of biofilms was done by the Tissue Culture Plate assay described by Christensen et al considered as standard test for detection of biofilm formation. Optical density (OD) of stained adherent bacteria was determined with a micro ELISA auto reader at wavelength of 570 nm. These OD values were considered as an index of bacteria adhering to surface and forming biofilms.
Results: Out of 250 urine samples investigated for UTI, 100 samples showed significant bacteriuria. Out of 100 samples showing significant bacteriuria, the prevalence rate of uropathogenic organisms was found to be in order of E.coli 88 (88%), Staphylococcus aureus 4(4%), Pseudomonas aeruginosa 2 (2%), Klebsiella pneumoniae 2 (2%), Enterococcus sps 3 (3%) and Citrobacter koseri 1 (1%). Results indicated that quinolones and fluoroquinolones groups of drugs were most potent of all the antibiotics. ESBL production was detected among 17 (17%) out of 100 uropathogenic isolates. Biofilms production was detected from Uropathogenic organisms by Tissue Culture Plate in 20 (20%).
Conclusion: Significant correlation between Biofilm production and multidrug resistance was seen in the study. It is therefore recommended that routine microbiological analysis, antibiotic sensitivity test of mid-stream urine samples and biofilm detection of patients with symptoms of UTI and other asymptomatic patients be carried out so as enhance in the administration of drugs for the treatment and management of UTIs.
Key words: Biofilm, Antibiotic resistance, Urinary tract infection.