Treponema medium sp. nov., Isolated from Human Subgingival Dental Plaque

Abstract

A new Treponema species, for which we propose the name Treponema medium, was isolated from subgingival plaque from an adult with periodontal disease. The morphological characteristics, differential biochemical characteristics, and protein profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels of this organism are described. The guanine-plus-cytosine content of the DNA of T. medium is 51 mol%. The levels of DNA-DNA relatedness of the new species to other Treponema species, including Treponema denticola, Treponema vincentii, Treponema socranskii, Treponema pallidum, and Treponema phagedenis, are less than 30%. A phylogenetic analysis based on 16s rRNA sequences distinguished the new Treponema strain from strains belonging to previously described Treponema species. The type strain of T. medium is strain G7201.The incidence and numbers of treponemes in the human gingival flora become greater as gingivitis becomes more severe (27). The number of treponemes increases to approximately more than 50% of all bacterial morphotypes in subgingival samples from periodontitis patients (10,12,13,27). Some oral treponemal species have been associated with soft-tissue damage due to proteolytic enzymes or with inflammatory reactions due to antibodies against their specific antigens, and eventually this leads to periodontal tissue destruction in certain types of periodontal disease (12,18,21,36). Simonson et al., for instance, have reported that Treponema denticola is linked to the severity of periodontal disease (25). All of the human oral spirochetes mentioned above belong to the genus Treponema in the family Spirochaetaceae; these bacteria characteristically are tightly coiled organisms that consist of a protoplasmic cylinder (length, approximately 6 to 20 pm; width, 0.1 to 0.5 pm) covered by an envelope (an outer sheath) and periplasmic flagella (axial flagella) which originate subterminally at the ends of the protoplasmic cylinder (26). Choi et al. used a 16s rRNA gene cloning technique to document the qualitative nature of human oral spirochetes and demonstrated that there is great genetic diversity in oral spirochetes, even in a single periodontitis patient (2). Human oral spirochetes, however, have been conventionally grouped into the following three morphotypes: (i) small spirochetes, including T. denticola, Treponema socranskii, and Treponema pectinovorum; (ii) medium-sized spirochetes, such as Treponema vincentii; and (iii) large spirochetes which have not been isolated in pure culture (3, 11). related spirochete with different periodontal status and reported that human oral spirochetes were not uniformly distributed within the dentition or around individual teeth T. denticola, T. socranskii, T. pectinovorum, T. vincentii,We isolated Treponema sp. strain G7201T (T = type strain), which could not be classified in any previously described species. We examined the phenotypic, serologic, and genetic characteristics of this organism and compared the results with data for reference species.In this paper we ...

Detection and Quantification of Oral Treponemes in Subgingival Plaque by Real-Time PCR

“…Moreover, the oral treponemes T. denticola, T. vincentii, and T. medium have also been identified in subgingival plaque (2,7,14,28). However, although most putative periodontopathogenic organisms have been cultured under anaerobic condi- a TT, total treponemes.…”

Treponemal glycoconjugate inhibits Toll‐like receptor ligand‐induced cell activation by blocking LPS‐binding protein and CD14 functions

“…Oral spirochetes, which generally belong to the genus Treponema, are found in subgingival plaque from patients with periodontal diseases [1,2] and have conventionally been classified into three morphogroups: small-, intermediate-, and large-sized. Treponema medium is an intermediate-sized treponeme [3] that has been found in increased numbers in subgingival plaque samples from deep periodontal pockets using real-time PCR assays [4].…”

Treponema parvum sp. nov., a small, glucoronic or galacturonic acid-dependent oral spirochaete from lesions of human periodontitis and acute necrotizing ulcerative gingivitis.

“…The combination of in vitro phenotypic characterization and phylogenetic classification has led recently to the description of four novel oral spirochaetes : Treponema amylovorum (Wyss et al, 1997), Treponema lecithinolyticum (Wyss et al, 1999), Treponema maltophilum and Treponema medium (Umemoto et al, 1997). Speciesspecific or group-specific DNA probes based on characteristics of the respective 16S rRNA sequences could be applied to detailed culture-independent epidemiological investigations of the association of different treponemes with various forms of oral disease (Moter et al, 1998 ;Wyss et al, 1999 ;Paster et al, 1999).…”