Biofilm Production and Antibiotic Susceptibility of Planktonic and Biofi lm Bacteria of Canine Dental Tartar Isolates

Manuel, Atulya and Rao, Venkata J and Jesil, Aranjani Mathew (2014) Biofilm Production and Antibiotic Susceptibility of Planktonic and Biofi lm Bacteria of Canine Dental Tartar Isolates. Acta Scientiae Veterinariae, 42 (1202). pp. 1-6. ISSN 1679-9216

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Background: In nature, bacteria prefer to live as a community rather than planktonic cells. Biofi lm is such a community of bacteria embedded in a coherent cluster of polysaccharides, proteins and nucleic acids. The biofi lm formation in the dental cavity can result in the development of periodontal diseases. Biofi lm in the oral cavity can affect the general health of the dog and the bacterial toxins can damage the visceral organs engaged in detoxifi cation. It can also be detrimental to human health when transferred via animal bites. Aim of this study is to isolate the organisms from the dental tartars of dogs and to study their response to antibiotics in both planktonic and biofi lm mode of life.Materials, Methods & Results: Organisms were isolated from fourteen canines with dental tartar using brain heart infusion agar medium. They were identifi ed as per Bergy’s Manual. Antibiogram of the isolates were done with the Kirby Bauer method using standard antibiotic discs. Initial screening of biofi lm production was done using the congo red agar assay. Quantifi cation of biofi lms were done using a standard microtitre plate method using crystal violet staining. The minimum inhibitory concentration and minimum biofi lm eradication concentration were compared to determine the change in the antimicrobial susceptibility pattern of dental tartar isolates when they go from the planktonic to the biofi lm mode of growth.Minimum inhibitory concentrations (MIC) of four broad spectrum antibiotics on isolated strains were determined as per CLSI guidelines. Minimum biofi lm eradication concentrations (MBEC) of the tested antibiotics were calculated for the isolates using a standard microtitre plate MBEC assay. Bacterial biofi lm formation provides the bacteria inherent resistance to antibiotic chemotherapy and helps in the persistence of infection. The dental plaque is a dental biofi lm which gets calcifi ed and becomes dental tartar. In the present study, the isolated organisms were identifi ed as Pseudomonas fragi (43%),Citrobacter koseri (14%), Streptococcus mutans (33%) and Malassezia pachydermatis (10%). The bacteria in biofi lm mode of growth exhibited signifi cantly higher antibiotic resistance compared to the planktonic state of the same organisms. Congo red assay revealed that all the P. fragi isolates, two C. koseri isolates and four S. mutans isolates are biofi lm producers. The biofi lm production was highest with P. fragi isolates as per the results of the crystal violet assay. A synergistic effect in biofi lm production was found when the organisms in combination were allowed to produce biofi lm. The isolates showed high sensitivity towards Chloramphenicol (90%), Ciprofl oxacin (90%), Enrofl oxacin (90%), Ceftriaxone (80%) and low sensitivity towards Gentamicin (66%), Cephotaxim (66%) and Sulphadiazine (50%). Discussion: The minimum biofi lm eradication concentration of the isolates was found to be much higher compared to the MIC range of the planktonic bacteria. Conventional antibiotic therapy against bacterial infections are based on the sensitivity pattern of organisms towards the respective antibiotics. The results of the present study indicate the requirement of a higher concentration of antibiotics needed for eradication of bacterial biofi lms. Antibiotics are not free from toxic side effects. Hence, agents promoting the biofi lm eradication are a safer choice rather than increasing antibiotic concentration.More studies in this line are in progress.

Item Type: Article
Uncontrolled Keywords: Dental tartar; Biofi lm; Crystal violet assay; Minimum biofi lm eradication concentration
Subjects: Pharmacy > MCOPS Manipal > Pharmaceutical Biotechnology
Depositing User: KMC Library
Date Deposited: 18 Feb 2017 09:41
Last Modified: 18 Feb 2017 09:41

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