Forging a link between bacterial biofilms and drug resistance: an unsolved mystery


  • Pallavi Sayal Department of Microbiology, BPS, GMC, Khanpur Kalan, Sonepat, Haryana, India
  • Raminder Sandhu Department of Microbiology, BPS, GMC, Khanpur Kalan, Sonepat, Haryana, India
  • Kanwardeep Singh Department of Microbiology, GMC, Amritsar, Punjab, India



Antibiotic resistance, Biofilms, Ciprofloxacin, Pseudomonas aeruginosa


Background: Though use of various medical devices as indwelling catheters, cardiac pacemakers, prosthetic heart valves, chronic ambulatory peritoneal dialysis catheters, and prosthetic joints has greatly facilitated management of serious illness. Bacterial strategies to colonize and grow as biofilms on these devices are major cause of morbidity among patients receiving prosthesis.

Methods: Fifty Pseudomonas aeruginosa (P. aeruginosa) strains isolated from the urine samples of catheterized patients were subjected to biofilm detection by Tissue Culture Plate method and MIC of ciprofloxacin was determined against them using broth dilution method.

Results: In our study 50 (7.69%) P. aeruginosa isolates were subjected to biofilm screening by TCP. Among 50 isolates, TCP method detected 40 (80.00%) biofilm producers. Out of which 28/50 (56.00%) were high, 12/50 (24.00%) were moderate and 10/50 (20%) were non/weak biofilm producers. MIC for ciprofloxacin was detected for P. aeruginosa strains at various concentrations (0.25ug/ml -8ug/ml). We observed that the MIC range for high biofilm producing P. aeruginosa was between 4- 8ug/ml, whereas for non-biofilm producers MIC range varies from 0.25 to 1ug/ml. Thus, biofilm can pose a threat in patient treatment.

Conclusions: The armament of various bacteriostatic or bactericidal agents available to treat infections are restricted to act in planktonic phase and these agents did not take into account the unique biology of bacterial biofilms. Thus, bacteria growing as biofilm communities often result in troublesome complications as persistent infections, which cannot be resolved with standard antibiotic treatments. As, biofilm communities embedded in exopolysaccharide have not been considered until recently, therapeutic strategies to treat them are not available yet.


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How to Cite

Sayal, P., Sandhu, R., & Singh, K. (2016). Forging a link between bacterial biofilms and drug resistance: an unsolved mystery. International Journal of Research in Medical Sciences, 4(12), 5341–5344.



Original Research Articles