Comparison of the virulence of exopolysaccharide-producing Prevotella intermedia to exopolysaccharide non-producing periodontopathic organisms.

Background: Evidence in the literature suggests that exopolysaccharides (EPS) produced by bacterial cells are essential for the expression of virulence in these organisms. Secreted EPSs form the framework in which microbial biofilms are built.

Methods: This study evaluates the role of EPS in Prevotella intermedia for the expression of virulence.

Reduction of two red complex bacteria by sustained-release doxycycline and correlation to improvement in mean pocket depth.

Objective: The objective was to evaluate the effects of an 8.5% sustained-release doxycycline-containing polymer formulation (SRDF) on deep pockets (pocket depth [PD] ≥ 7 mm) in chronic periodontitis. Total bacterial counts were used to estimate the number of viable bacteria present before treatment and for up to 6 months posttreatment.

Genetic analysis of mobile tetQ elements in oral Prevotella species.

Prevotella species are members of the bacterial oral flora and are opportunistic pathogens in polymicrobial infections of soft tissues. Antibiotic resistance to tetracyclines is common in these bacteria, and the gene encoding this resistance has been previously identified as tetQ. The tetQ gene is also found on conjugative transposons in the intestinal Bacteroides species; whether these related bacteria have transmitted tetQ to Prevotella is unknown.

Treating chronic periodontitis: current status, challenges, and future directions.

Periodontitis affects roughly one-third of the US population. A timely diagnosis of chronic periodontitis at its earliest stage is essential to avoid more challenging severe stages of the disease. Most cases of slight and moderate chronic periodontitis can be successfully managed by mechanical removal and/or reduction of subgingival bacterial biofilms and calculus.

Gene expression profile and pathogenicity of biofilm-forming Prevotella intermedia strain 17.

Background: Prevotella intermedia (P. intermedia), a gram-negative, black-pigmented anaerobic rod, has been implicated in the development of chronic oral infection. P.

Microbiologic changes following administration of locally delivered doxycycline in smokers: a 15-month follow-up.

Background: Additional clinical benefits have been reported with the use of locally delivered antimicrobials in the treatment of smokers; however, long-term changes in the subgingival microbiota following the use of these drugs in smokers have not been documented. The aim of this study was to evaluate long-term microbiologic changes following locally delivered doxycycline in the treatment of smokers.

Methods: Sixteen smokers with chronic periodontitis presenting a minimum of four pockets (probing depth>or=5 mm) were selected.

Detection and characterization of beta-lactamase genes in subgingival bacteria from patients with refractory periodontitis.

Fifty-three beta-lactamase-producing strains of oral bacteria isolated from patients with refractory periodontitis in Norway and USA were screened for the presence of the bla(TEM), bla(SHV), bla(OXA), bla(ampC), bla(cfxA), and bla(cepA/cblA) genes by the polymerase chain reaction (PCR). The PCR products were characterized by direct sequencing of the amplified DNA. Thirty-four of the 53 enzyme-producing strains (64%) were positive in one of the PCR assays.

Subantimicrobial dose doxycycline enhances the efficacy of scaling and root planing in chronic periodontitis: a multicenter trial.

Background: Previous studies have shown that subantimicrobial dose doxycycline (SDD) is of clinical benefit in the treatment of chronic periodontitis (CP). The aim of this study was to further assess the role of SDD as an adjunct to scaling and root planing (SRP) in the treatment of CP.

Methods: A double-blind, randomized, placebo-controlled, multicenter clinical study was conducted to test the efficacy of SDD (20 mg doxycycline B.

A Role for Antibiotics in the Treatment of Refractory Periodontitis.

Refractory periodontitis is considered by many investigators to be a separate disease entity that is descriptive of a particular patient who has multiple sites, rather than a few individual sites, that do not respond to conventional periodontal treatment modalities. Such patients continue to demonstrate loss of attachment and alveolar bone despite frequent periodontal treatment which includes surgical intervention, scaling and root planing, and often systemically-administered tetracycline. Controlled clinical studies have demonstrated that both clindamycin-hydrochloride and amoxicillin/clavulanate potassium (Au) are beneficial when used in conjunction with periodontal scaling.

Current Status of Systemic Antibiotic Usage in Destructive Periodontal Disease.

The recognition that periodontal diseases are primarily caused by specific microorganisms has led researchers to explore the possibility that antibiotics may enhance the effect of mechanical debridement procedures such as scaling and surgery. For some selected periodontal diseases, this has proven to be true. This paper will review systemically-administered antibiotics and the clinical studies and case reports supporting their use.

Antibiotic Susceptibilities of Periodontal Bacteria: In Vitro Susceptibilities to Eight Antimicrobial Agents.

In vitro susceptibilities of 369 to 966 bacterial isolates from periodontal lesions to eight antibiotics were determined by agar dilution technique as a means of determining which antimicrobial agents were inhibitory for bacteria frequently associated with destructive periodontal diseases. Although most bacteria were relatively susceptible to the penicillins, greater activity was generally noted with amoxicillin than with either penicillin or ampicillin with the exception of Selenomonas sputigena and Peptostreptococcus. Antibacterial activities obtained with minocycline were significantly higher than with tetracycline for Actinobacillus actinomycetemcomitans and Streptococcus but comparable for most other taxa.