Carious Dentine Provides a Habitat for a Complex Array of Novel Prevotella -Like Bacteria

Abstract

Previous analysis of the microbiology of advanced caries by culture and real-time PCR emphasized the high incidence and abundance of gram-negative anaerobic species, particularly Prevotella-like bacteria. The diversity of Prevotella-like bacteria was further explored by analyzing pooled bacterial DNA from lesions of carious dentine. This was achieved by amplification of a region of the 16S ribosomal DNA with a Prevotella genusspecific forward primer and a universal bacterial reverse primer, followed by cloning and sequencing. Cultured Prevotella species commonly associated with oral tissues constituted only 12% of the Prevotella clones isolated from advanced carious lesions. The remaining 88% consisted of a diverse range of phylotypes. These included five clusters of previously recognized but uncultured oral Prevotella spp. and a major cluster containing Prevotella-like bacteria most closely related to uncharacterized rumen bacteria. Cluster-specific primers were designed, and the numbers of bacteria within clusters were quantified by real-time PCR, confirming the abundance of these organisms. The data indicated that advanced dental caries provides a unique environment for a complex array of novel and uncultured Prevotella and Prevotella-like bacteria which, in some cases, may dominate the diverse polymicrobial community associated with the disease.

Prevotella multisaccharivorax sp. nov., isolated from human subgingival plaque

“…Nadkarni et al (2004) suggested that the numerically dominant cluster VI in the carious dentine lesions, which contains Prevotella sp. oral clone IDR-CEC-0032, represents a novel genus, which was most closely related to uncharacterized Prevotella-like rumen bacteria (93-94 % similarity).…”

“…NT 2 Enzyme activities: oral clone IDR-CEC-0032 (Nadkarni et al, 2004) with about 99 % similarity. Nadkarni et al (2004) suggested that the numerically dominant cluster VI in the carious dentine lesions, which contains Prevotella sp.…”

“…Prevotella and Prevotella-like bacteria (Nadkarni et al, 2004). Prevotella species have also been isolated from the genitourinary tract, vagina and cervix.…”

“…In addition, the isolates were related to Prevotella sp. oral clone IDR-CEC-0032, which is a representative of the numerically dominant cluster VI in carious dentine lesions [Nadkarni et al (2004). J Clin Microbiol 42, 5238-5244], with about 99 % similarity.…”

Prevotella maculosa sp. nov., isolated from the human oral cavity

“…The G+C content of the DNA of the type strain is 48 mol%. The type strain of Prevotella maculosa is W1609 T (5DSM 19339 T 5CCUG 54766 T ).Prevotella species are part of the normal human oral microbiota and are also frequently isolated from oral infections such as periodontitis, dental caries and abscesses (Dymock et al, 1996;Paster et al, 2001;Nadkarni et al, 2004). However, many isolates encountered in clinical samples cannot be assigned to species with validly published names.…”