Sulfate-reducing bacteria in the periodontal pocket

This report is the first to describe the occurrence of sulfate-reducing bacteria in the human mouth. Samples of subgingival dental plaque were examined for the presence of sulfate-reducing bacteria. Using enrichment cultures, sulfate-reducing bacteria were detected in 25 (58%) of 43 individuals, and in 39 (48%) of the 82 samples. Pure isolates of sulfate-reducing bacteria, obtained from a limited number of enrichment cultures, belonged to the genera Desulfobacter and Desulfovibrio. These genera are also the predominant sulfate-reducing bacteria in the human large intestine. The sulfate-reducing bacteria use sulfate as terminal electron acceptor to oxidize low-molecular-weight organic compounds, mainly products of microbial fermentation such as acetate, lactate etc. The numbers of sulfate-reducing bacteria in the mouth are assumed to be limited by sulfate. Potential sources of sulfate in the subgingival area include free sulfate in pocket fluid and glycosaminoglycans from periodontal tissues.     

Anaerobic bacteria in dentoalveolar infections

The bacteriology of 57 dentoalveolar infections was studied using optimal techniques to collect, transport and process specimens. There was an average of 4 bacterial species per specimen, and only 1/3 of the specimens held aerobes. Among the aerobic bacteria, streptococci dominated and among the anaerobes the Gram-negative rods, Bacteroides ruminicola and Fusobacterium nucleatum, were most frequently isolated followed by Gram-positive cocci, in particular Streptococcus intermedius. All aerobic isolates were resistant to penicillins but sensitive to clindamycin and tinidazole. The other anaerobic isolates were sensitive to penicillins but showed varying susceptibility to erythromycin and doxycycline. Tinidazole was effective against all anaerobic Gram-negative rods. The presence of volatile fatty acids in pus from dentoalveolar infections was found to be of presumptive value for the diagnosis of anaerobic infections. Direct gas-liquid chromatographic analysis of pus is recommended as a routine procedure for preliminary diagnosis of anaerobic dentoalveolar infections.     

Anaerobic bacteria in dentoalveolar abscesses

The present study was initiated to determine the bacteriology of 40 orofacial abscesses of dental origin in patients who had taken antibiotics for several days. Bacteria were isolated from all but 2 specimens. Aerobic or facultative anaerobic bacteria were isolated in 21 cases, obligate anaerobic bacteria in 17 cases, whereas in 11 cases, polymicrobial growth was revealed. The average number of bacterial species was 2.1 per specimen. Gram positive aerobic micro-organisms predominated, namely, Staphylococcus epidermidis followed by Streptococci (group A) and Staphylococcus aureus. Among obligate anaerobes, Gram positive micro-organisms, peptostreptococci and peptococci were more often isolated, in the following decreasing order: Ps. productus, Ps. intermedius, Ps. parvulus, Ps. anaerobius, Pc. constellatus, Pc. prevotii. Gram negative anaerobic rods were detected in a small number of cases, namely B. corrodens, B. fragilis, B. melaninogenicus, B. ochraceus, B. oralis. Quantitative determination did not show any meaningful difference between aerobic and anaerobic isolates. Susceptibility tests against a series of antibiotics showed that ampicillin was the most active in aerobes and cefoxitin in anaerobes.     

Anaerobic bacteria in jaw cysts

The bacterial flora of the fluid content of 54 cysts of the jaws with a history suggestive of infection were studied. Forty-seven of these cysts were subsequently considered to be infected and from 78.6% of these, positive bacterial cultures were developed. Of the bacterial strains 89.2% were anaerobes and only 10.8% were pure aerobes or facultative anaerobes. Microorganisms isolated from each specimen ranged from 1 to 4 bacterial species. Gram positive anaerobic cocci revealed to be the most frequent bacterial group (36.9%), followed by Gram negative anaerobic rods (29.8%), Gram positive aerobic cocci being the third most common group of the isolates (19.0%). Antibiotic sensitivity tests of the isolated anaerobic cocci to a group of nine antibiotics revealed chloramphenicol and minocycline as the most effective. All anaerobic rods tested, were sensitive to metronidazole.     

Chronology of an interdental periodontal lesion

Abstract A case in which intermittent and spontaneous periodontal breakdown and repair has occurred on two different occasions in the same interproximal site over a period of 18 years is described. The possible etiology of the lesions is discussed in terms of current concepts of localized bacterial selectivity. Also reviewed is the potential for repair in two-walled infrabony defects.     

Serum antibodies to periodontal bacteria

The purpose of this study was to determine how serum antibodies reactive with periodontitis-associated bacteria with relates to the diagnosis of periodontitis subjects. Study groups included localized juvenile periodontitis (LJP) subjects, severe periodontitis (SP) subjects, chronic adult periodontitis (AP) subjects, and age matched controls. Twenty-two bacterial strains, representing 18 different species most commonly found in early onset periodontitis were evaluated using serum from LJP, SP, and age matched controls. Serum IgG reactive with these organisms was determined using a radioimmunoassay (RIA). Serum antibody reactive with 13 bacterial strains differed significantly (P less than 0.01) between the three clinical groups. Discriminate analysis revealed that antibodies reactive with 5 bacterial strains of the 13 were able to identify the clinical group to which subjects belonged 79% of the time with control subjects being correctly identified 100% of the time, LJP subjects 78% of the time, and SP subjects 60% of the time. These strains included two strains of Actinobacillus actinomycetemcomitans (Y4 and N27), Fusobacterium nucleatum (E1D1), Eubacterium brachy, and Bacteroides gingivalis. The low classification rate of SP subjects suggested heterogeneity. The SP group could be divided into three subgroups using the serological data. One subgroup, with "super" severe attachment loss, generally lacked antibody reactive with these five organisms, another subgroup was serologically similar to LJP subjects, while the third subgroup had antibodies to additional organisms. This suggests that some SP subjects may represent a more advanced form of LJP. Comparison of antibody reactivity of AP subjects with age matched controls to 23 bacterial types revealed that mean serum antibody reactivity to only Bacteroides gingivalis was higher in AP subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Distribution of enzymatically pathogenic bacteria from periodontal pocket in advancing periodontitis

Production of 9 enzymatic activities of 527 strains freshly isolated from periodontal pockets in advancing periodontitis were investigated. Of these isolates, two strains showed lecithinase activity on egg yolk agar plate. Collagenase, plasmin and lipase were produced by 28 strains, 26 strains and 22 strains, respectively. Two lecithinase-producing strains were identified as Bacteroides intermedius. Nineteen strains of B. intermedius and 1 strain of Fusobacterium species produced lipase on egg yolk agar plate. All of the 28 collagenase-producing strains were B. gingivalis. B. gingivalis (20 strains) and non black-pigmented Bacteroides (6 strains) showed plasmin activity. These results indicate that Bacteroides species, mainly B. gingivalis and B. intermedius may exert an important influence on the exacerbation of the disease.