Microbiota of Dental Abscess and their Susceptibility to Empirical Antibiotic Therapy

Resistant pathogens to purulent odontogenic infections have evolved due to misuse of antibiotics. Hence, it is important to use a suitable antibacterial agent.

This study aimed to identify the common bacterial species causing odontogenic infections and to determine their antibiotic susceptibility profile to amoxicillin, amoxicillin and clavulanic acid, azithromycin, and linezolid.

This was an in vitro cross-sectional study.

Fifty pus samples from odontogenic abscess were cultured and antibiotic susceptibility tests were performed as per the standard microbiological procedures.

Binomial test and Pearson's Chi-square test were used for statistical analysis.

Out of the 50 samples cultured, 30 samples showed growth. The distribution of growth among the 30 samples was Gram-positive cocci (n = 23, 67.65%) and Gram-negative bacilli (n = 11, 32.35%). Gram-positive isolates that were grown were Enterococcus faecalis (38.24%) followed by Staphylococcus aureus (29.41%) and Gram-negative bacilli that were isolated were Klebsiella pneumoniae (14.71%), Pseudomonas aeruginosa (8.82%), Escherichia coli (5.88%), and Enterobacter (2.94%). Enterococcus isolates were highly susceptible to amoxicillin (76.92%). An increase in the zone of inhibition to amoxicillin-clavulanic acid was appreciated more for Staphylococcus (50%) than Enterococcus (30.76%). Enterococcus and Staphylococcus showed high susceptibility of 92.31% and 90% to linezolid, respectively. E. coli and Enterobacter were 100% susceptible to amoxicillin. All the Gram-negative bacteria except for P. aeruginosa were 100% highly susceptible to amoxicillin-clavulanic acid.

Culture-guided antibiotic prescriptions are necessary to prevent the emergence of antibiotic-resistant bacteria.