As carbapenems-resistant bacteria increase with the frequent use of carbapenems, we studied the isolation frequency and the resistant mechanism of imipenem-resistant bacteria in pus from oral infectious diseases, using CDC blood agar culture plates containing 2.0μg/mL of imipenem. Carbapenem-resistant bacteria were detected from all 8 patients, and imipenem-resistant anaerobic gram-negative rods were detected from 5 patients. These rods showed resistance to carbapenems, cefmetazole, and ampicillin. β-Lactamase was detected in 3 strains ofPrevotella, by nitrocefin. The β-lactamase gene was different fromblaIMP.
The study suggests that highly carbapenem-resistant bacteria are isolated from oral infection. However, the DNA sequence of β-lactamase in imipenem-resistantPrevotellawas different from that of facultative gram negative rods.
