High Virulence and Multidrug Resistance of Escherichia coli Isolated in Periodontal Disease.

Periodontal disease is caused by different gram-negative anaerobic bacteria; however, has also been isolated from periodontitis and its role in periodontitis is less known. This study aimed to determine the variability in virulence genotype, antibiotic resistance phenotype, biofilm formation, phylogroups, and serotypes in different emerging periodontal strains of , isolated from patients with periodontal disease and healthy controls. , virulence genes, and phylogroups, were identified by PCR, antibiotic susceptibility by the Kirby-Bauer method, biofilm formation was quantified using polystyrene microtiter plates, and serotypes were determined by serotyping. Although was not detected in the controls ( = 70), it was isolated in 14.7% (100/678) of the patients. Most of the strains ( = 81/100) were multidrug-resistance. The most frequent adhesion genes among the strains were and , toxin genes were and , iron-acquisition genes were and and protectin genes were and . Phylogroup B2 and serotype O25:H4 were the most predominant among the strains. These findings suggest that may be involved in periodontal disease due to its high virulence, multidrug-resistance, and a wide distribution of phylogroups and serotypes.