Biofilm Formation and Detection in Multi-drug Resistant Staphylococcus

Abstract

Background: Biofilm formation is an ultra thin slimy layer produced by certain bacteria that imparts very significant
resistance against variety of antibiotics. Biofilm can be detected by tube and microtiter plate essay
Objectives: To detect biofilm formation in Staphylococci isolated from various clinical samples received from
hospitalized patients of Lahore General Hospital, Lahore and to compare biofilm detection by the Tube method
and Microtitre plate assay
Study design: Experimental study
Place and Duration of Study: Microbiology laboratory, Post Graduate Medical Institute (PGMI), Lahore
from December 2012 to June 2014
Material and Method: All specimens obtained from LGH were processed, Staphylococci species were isolated by
routine microbiological and biochemical tests. Antibiotic sensitivity pattern was found out by modified Kirbybauer
disc diffusion method and multi-drug resistant Staphylococci species were selected for further processing.
Staphylococcal isolates along with the controls were subjected to biofilm formation by two methods, Tube Method
(qualitative) and Microtitre Plate Assay (quantitative).
Results: Biofilm formation was more commonly observed in the microorganisms with multi-drug resistance.;
Penicillin, 92 (97.87%); Cefoxitin, 56 (59.57%); Erythromycin, 64 (68.08%); Clindamycin, 51 (54.25%); Floroquinolones,
38 (40.42%); Doxycyclin, 47 (50.00%); Linezolid, 6 (6.38%); Trimethoprim-Sulphmethaxazole, 77 (81.91);
Gentamicin, 36 (38.29%) Staphylococci species were resistant. Among the Staphylococcal isolates, resistant 88.29%
Penicillin, 47.87% Cefoxitin, 72.32% Trimethoprim-Sulphmethaxazole, 61.70% Erythromycin, 48.93% Clindamycin,
35.10% Flouroquinolones, 43.61% Doxycyclin, 5.31% Linezolid, 31.91% Gentamicin depicted biofilm formation
by the Tube Method. While among the Staphylococcal isolates resistant, 96.81% Penicillin, 56.38% Cefoxitin,
81.91% Trimethoprim-Sulphmethaxazole, 67.02% Erythromycin, 53.19% Clindamycin, 40.42% Flouroquinolones,
47.87% Doxycyclin, 6.38% Linezolid, 37.23% Gentamicin depicted biofilm formation by the Microtitre
plate Assay.
Conclusion: Multiple drug resistant staphylococci are more prone to form biofilm and Microtitre plate assay is
effective at determining biofilm as compared to Tube method