ROLE OF PORPHYROMONAS-GINGIVALIS, PREVOTELLA-INTERMEDIA, AND PREVOTELLA-NIGRESCENS IN EXTRAORAL AND SOME ODONTOGENIC INFECTIONS

Porphyromonas gingivalis, Prevotella intermedia, and Prevotella nigres cens were isolated from 138 subjects with various infections (intraabd ominal, skin and soft-tissue, head and neck, pleuropulmonary, and odon togenic infections and bacteremia). The phenotypic identification of 1 73 isolates was completed by molecular methods. Arbitrarily primed pol ymerase chain reaction (AP PCR) analysis was used to determine the gen etic similarity of intraindividual P. intermedia/P. nigrescens group i solates recovered from 12 subjects, All 19 P. gingivalis isolates (16 intraabdominal isolates and three odontogenic isolates) hybridized wit h the P. gingivalis-specific DNA probe, Of the 154 P. intermedia/P. ni grescens group isolates, 74 were identified as P. intermedia; 78, as P . nigrescens; and 2, as P. intermedia/P. nigrescens-like isolates, P. intermedia and P. nigrescens were isolated with equal frequency from p atients with all other infections except those with bacteremia, from w hom only P. nigrescens isolates were recovered. There were 12 cases in which multiple P. intermedia/P. nigrescens group isolates were recove red; in nine, only one of the species was isolated, whereas in three, two different species were detected, The intraindividual isolates repr esenting the same species always exhibited identical AP PCR genotypes.