Detection of Drug Susceptible and Resistant Viridans Streptococci sp., Staphylococcus Aureus, Klebsiella Pneumoniae and E.coli in Complete Denture Patients and Visualisation using Scanning Electron Microscopy

摘要

The bacteria colonising the oral cavity and the dentures acquire drug resistance due to frequent usage of antibiotics systemically and application of mouth rinses and denture disinfectants locally. These multidrug resistant bacteria pose potential threat to the health of the patient as infections caused by them do not respond to conventional antibiotics.Aim: The present study aims at detecting the drug resistant bacteria in patients who wear complete dentures.Materials and Methods: The study is a descriptive study and follows laboratory invitro study design involving 30 complete denture patients. Swabs were collected from their oral cavity as well as complete denture surfaces. Antibiotic sensitivity tests were performed for the following bacteriae namely Viridans streptococci species, Staphylococcus aureus , Klebsiella pneumoniae and E.coli . Isolation of the bacteria were done by means of selective media and subjected to biochemical tests. The 16S rRNA sequencing was done to ascertain the microorganisms by which 20 isolates of each of the selective bacteria were obtained. The bacteria were classified as sensitive, intermediate sensitive and resistant based on antibiotic sensitivity tests. Those isolates which exhibited Multi-Drug Resistance (MDR) were visualised using SEM.Results: Viridans streptococci sp. (40%) and Staphylococcus aureus (25%) isolates were resistant to Amoxiclavulinic acid and Methicilin, whereas Klebsiella pneumoniae (30%) and (30%) E.coli isolates were most resistant to Cefotaxime and Doxicilin.Conclusion: Drug resistant bacteria have been identified from complete dentures and oral cavity in the present study. Antibiotic sensitivity tests, 16S rRNA sequencing and SEM are vital investigative tools to detect and to visualise drug resistant bacteria. Cell density, Extracellular Polymeric Substances (EPS) and capsule could be important factors for providing drug resistance.