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Oral Microbiology and Immunology Aug 1994Previous studies have shown increased levels of proteolytic enzymes in affected periodontal sites. The aim of the present investigation was to evaluate the effect of... (Comparative Study)
Comparative Study
Previous studies have shown increased levels of proteolytic enzymes in affected periodontal sites. The aim of the present investigation was to evaluate the effect of proteolytic environments on the lysis and growth of selected oral bacteria associated with either healthy or diseased periodontal sites. The effect of trypsin, chymotrypsin and proteinase K on cell lysis was determined following incubation with bacteria, whereas the effect of the same proteolytic enzymes on bacterial growth was tested using a disc-plate technique. Overall, gram-positive bacteria appeared to be more resistant to lysis than gram-negative bacteria. The most susceptible bacteria were Actinomyces spp., Eubacterium saburreum, Prevotella intermedia, Capnocytophaga ochracea, Fusobacterium nucleatum, Prevotella loescheii, Treponema denticola and Actinobacillus actinomycetemcomitans. The disc-plate procedure indicated that the growth of Actinomyces spp., E. saburreum, C. ochracea, P. intermedia, P. loescheii, Porphyromonas gingivalis and T. denticola were the most affected, more particularly by chymotrypsin and proteinase K. Interestingly, the growth of F. nucleatum was rather stimulated by proteolytic enzymes. The observations reported in this investigation indicate that specific and general proteolytic activities have the ability to lyse some oral bacterial species and to interfere with their growth. It is suggested that such effects could represent new mechanisms by which the bacterial ecology of subgingival sites may be affected.
Topics: Actinomyces; Aggregatibacter actinomycetemcomitans; Animals; Bacteriolysis; Campylobacter; Capnocytophaga; Cattle; Chymotrypsin; Ecosystem; Endopeptidase K; Eubacterium; Fusobacterium nucleatum; Gram-Negative Bacteria; Gram-Positive Bacteria; Lactobacillus; Microbial Sensitivity Tests; Periodontium; Porphyromonas gingivalis; Prevotella; Serine Endopeptidases; Streptococcus; Symbiosis; Time Factors; Treponema; Trypsin; Veillonella
PubMed: 7478762
DOI: 10.1111/j.1399-302x.1994.tb00062.x -
Oral Microbiology and Immunology Jun 1994Eruption of primary teeth has a great influence on the oral environment by providing suitable niches for bacterial colonization. The composition of oral gram-negative... (Comparative Study)
Comparative Study
Eruption of primary teeth has a great influence on the oral environment by providing suitable niches for bacterial colonization. The composition of oral gram-negative anaerobic microflora was investigated in 21 young children (mean age 32 months) with primary dentition. The bacterial findings of samples were compared with those of the same children collected at their edentulous infant period (mean age 3 months). During the primary period, 2 samples were collected from each child: a sample with dental floss from gingival margin of 2 teeth and stimulated saliva pooled with a mucosal swab sample. Both samples were cultured aerobically and anaerobically using nonselective and selective media. Prevotella melaninogenica, nonpigmented Prevotella spp., Fusobacterium nucleatum group and Capnocytophaga spp. were found in all children at the older age, whereas they occurred in edentulous mouth in 76%, 62%, 67% and 19%, respectively. The occurrence of Prevotella loescheii increased from 14% to 90%, Prevotella intermedia from 10% to 67%, Leptotrichia spp. from 24 to 71%, Campylobacter (Wolinella) spp. from 5 to 43% and Eikenella corrodens from 5 to 57%. Only the occurrence of Bacteroides gracilis and Veillonella spp. remained at about the same level. Species not isolated from the edentulous mouth, such as Prevotella denticola, Fusobacterium spp. other than the F. nucleatum group and Selenomonas spp. were now detected in 71%, 71% and 43% of the children. The stability of the colonizing P. melaninogenica strain(s) in the oral cavity was determined by using ribotyping; 1-2 isolates per child from the edentulous infant period of 9 children and 3-15 isolates per child from their primary dentition period were analyzed.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Bacterial Typing Techniques; Bacteroides; Capnocytophaga; Child, Preschool; Colony Count, Microbial; DNA, Bacterial; Female; Fusobacterium; Gram-Negative Anaerobic Bacteria; Humans; Longitudinal Studies; Male; Mouth; Mouth Mucosa; Prevotella melaninogenica; Tooth Eruption; Tooth, Deciduous; Veillonella
PubMed: 7936718
DOI: 10.1111/j.1399-302x.1994.tb00049.x -
Journal of Bacteriology Apr 1994The 2.4-kb plaA gene, which encodes a Prevotella loescheii galactoside-specific adhesin, contains a programmed frameshifting hop. The frameshift region consists of two...
The 2.4-kb plaA gene, which encodes a Prevotella loescheii galactoside-specific adhesin, contains a programmed frameshifting hop. The frameshift region consists of two UAA termination codons, two repeats of four identical bases between the terminators, and a stem-loop structure that has the potential to form a pseudoknot located downstream from the second UAA. The stem-loop and pseudoknot are features found in a number of retroviruses where frameshifting is a more common occurrence. The terminators, sequence repeats, and secondary structures were identified in both the P. loescheii plaA gene and the mRNA transcript. An in-frame fusion of the entire plaA frameshift region between codons 9 and 10 of the lacZ gene permitted relatively efficient expression (4 to 25% of that of the control) of beta-galactosidase in Escherichia coli.
Topics: Adhesins, Bacterial; Amino Acid Sequence; Bacteria; Bacterial Adhesion; Bacterial Proteins; Base Sequence; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genes, Reporter; Lac Operon; Lectins; Models, Genetic; Molecular Sequence Data; Nucleic Acid Conformation; Reading Frames; Recombinant Fusion Proteins
PubMed: 8144461
DOI: 10.1128/jb.176.7.1944-1948.1994 -
Oral Microbiology and Immunology Apr 1994Stimulated saliva and a pooled subgingival sample from the first molars were collected from 30 Caucasian women (mean age 30 years) for the presence of gram-negative...
Stimulated saliva and a pooled subgingival sample from the first molars were collected from 30 Caucasian women (mean age 30 years) for the presence of gram-negative anaerobic bacteria. The samples were inoculated on nonselective and selective media. The gram-negative anaerobic species occurring in the oral cavity of more than 50% of the subjects were selected for further analysis. Fusobacterium nucleatum and Prevotella melaninogenica were not recovered from subgingival sites without a simultaneous recovery in saliva. When positive subgingivally, Leptotrichia spp., nonpigmented Prevotella spp., Prevotella intermedia, Capnocytophaga spp., Bacteroides gracilis and Prevotella loescheii were simultaneously detected from saliva in 76%, 72%, 64%, 64%, 61% and 55% of the subjects, respectively. Intraindividually, the proportions of F. nucleatum, nonpigmented Prevotella spp., Leptotrichia spp., B. gracilis and P. loescheii of the anaerobic flora were quite similar in the salivary and subgingival samples. Capnocytophaga spp. and P. intermedia were present in higher proportions in subgingival samples than in saliva, whereas P. melaningogenica was present in higher proportions in saliva. Our data indicate that many oral gram-negative anaerobes are frequently recovered from stimulated saliva. Furthermore, when subgingivally positive, most subjects harbored these anaerobes simultaneously in saliva.
Topics: Adult; Dental Plaque; Female; Gram-Negative Anaerobic Bacteria; Humans; Saliva
PubMed: 8008430
DOI: 10.1111/j.1399-302x.1994.tb00047.x -
Oral Microbiology and Immunology Oct 1993Prevotella loescheii PK1295 produces at least 3 proteases that are separable by isoelectric focusing. One of these proteases, an enzyme with an isoelectric point at 8.5...
Prevotella loescheii PK1295 produces at least 3 proteases that are separable by isoelectric focusing. One of these proteases, an enzyme with an isoelectric point at 8.5 and an M(r) of 36,000, hydrolyzes the fimbria-associated adhesin on P. loescheii responsible for coaggregation with Streptococcus oralis 34, as well as gelatin, casein and fibrin. The action of this protease may contribute to the detachment of P. loescheii from its streptococcal coaggregation partner and provide a mechanism for bacterial relocation in dental plaque.
Topics: Adhesins, Bacterial; Bacterial Adhesion; Bacterial Proteins; Bacteroides; Dental Plaque; Electrophoresis, Polyacrylamide Gel; Fimbriae, Bacterial; Isoelectric Focusing; Peptide Hydrolases
PubMed: 7903444
DOI: 10.1111/j.1399-302x.1993.tb00575.x -
FEMS Immunology and Medical Microbiology Mar 1993Pigmented Prevotella spp. have been connected with oral infections as well as being part of the healthy gingival flora. The aim of this study was to determine the...
Pigmented Prevotella spp. have been connected with oral infections as well as being part of the healthy gingival flora. The aim of this study was to determine the presence of pigmented Prevotella spp. in saliva and gingival crevice samples from periodontally healthy adults. Twelve Caucasian female subjects (mean age 28 years, range 21-36 years) with no pockets > or = 4 mm, nor bleeding after probing were selected for this study. Paraffin-stimulated saliva was collected first; then, a pooled subgingival bacterial sample was taken with a sterile curette from mesiobuccal surfaces of all first molars. The samples were inoculated on to non-selective and selective media and incubated anaerobically. The most frequent species isolated were Pr. melaninogenica, Pr. intermedia and Pr. loescheü, found in 11, ten and nine subjects, respectively. The mean percentage of the total cultivable anaerobic microflora in salivary/subgingival samples were 14.7/0.6 for Pr. melaninogenica, 3.1/5.3 for Pr. intermedia and 2.6/1.2 for Pr. loescheii. Pr. denticola was found in one saliva sample and Pr. corporis, in two subgingival samples only. The number of different pigmented Prevotella spp. in the same mouth was 2-4 (mean 2.75). In conclusion, Pr. melaninogenica, Pr. intermedia and Pr. loescheii seem to be common microorganisms in the periodontally healthy oral cavity.
Topics: Adult; Bacteroidaceae; Female; Humans; Mouth; Reference Values; Saliva; Species Specificity
PubMed: 8518756
DOI: 10.1111/j.1574-695X.1993.tb00327.x -
FEMS Immunology and Medical Microbiology Mar 1993Black-pigmented Gram-negative anaerobes have been associated with periodontal disease and tooth loss since they were first isolated by Burdon in 1928. Porphyromonas... (Review)
Review
Black-pigmented Gram-negative anaerobes have been associated with periodontal disease and tooth loss since they were first isolated by Burdon in 1928. Porphyromonas gingivalis, which is usually not isolated from children, adolescents or adults with no periodontal breakdown, has been recognized as one of the most important periodontopathogens. Its presence is strongly correlated with deep periodontal pockets, which are assumed to be its main habitat. Correlations have been shown also with attachment loss, clinical inflammation and serum antibody levels, indicating an aetiological role in the periodontal disease. Their pathogenicity in animal models resembling periodontal disease is documented. They are frequently isolated from periodontal abscesses. The relationship between Prevotella intermedia and periodontal disease is not clear. It is frequently isolated from advanced periodontitis, often as the only black-pigmented Gram-negative anaerobic species; however, the prevalence in adults with no periodontal breakdown is high. It is found frequently in periodontal abscesses and in acute necrotizing and ulcerative gingivitis. Serogroup I is found predominantly in deep periodontal pockets, whereas all serogroups (I-III) are found in shallow pockets and gingivitis. No conclusive difference in pathogenicity between serogroups has been found. Pr. melaninogenica, Pr. denticola and Pr. loescheii are frequently found in the gingival crevice in preschool children and other age groups with gingivitis, but are seldom found in deep periodontal pockets.
Topics: Adolescent; Adult; Age Factors; Animals; Bacteroidaceae; Bacteroidaceae Infections; Child; Child, Preschool; Disease Susceptibility; Gingivitis; Humans; Mouth; Periodontal Abscess; Periodontitis; Racial Groups; Virulence
PubMed: 8518755
DOI: 10.1111/j.1574-695X.1993.tb00323.x -
FASEB Journal : Official Publication of... Mar 1993Nearly all human oral bacteria exhibit coaggregation, cell-to-cell recognition of genetically distinct cell types. Clumps or coaggregates composed of the two kinds of... (Review)
Review
Nearly all human oral bacteria exhibit coaggregation, cell-to-cell recognition of genetically distinct cell types. Clumps or coaggregates composed of the two kinds of cells are formed immediately upon mixing two partner cell types. Members of all 18 genera tested exhibit lactose-reversible coaggregation. Many of these interactions appear to be mediated by a lectin on one cell type that interacts with a complementary carbohydrate receptor on the other cell type. A lactose-sensitive adhesin has been isolated from Prevotella loescheii PK1295, and it exhibits the adherence properties observed with whole cells. Other adhesins have been identified and the genes for some of them have been cloned and sequenced. One Streptococcus sanguis adhesin is a lipoprotein that appears to have a dual function of recognizing both a bacterial carbohydrate receptor and a receptor in human saliva. Carbohydrate receptors for some adhesins have been purified from five oral streptococci, and they specifically block the coaggregations with the streptococcal partners that express the complementary adhesins. Coaggregation offers an explanation for the temporally related accretion of dental plaque and bacterial recognition of mucosal surfaces. Early colonizers of the tooth surface coaggregate with each other and late colonizers of the tooth surface coaggregate with each other, but with few exceptions, early colonizers do not recognize late colonizers. Furthermore, bacteria that colonize mucosal surfaces coaggregate with each other, indicating the high degree of specificity of coaggregation in the oral bacterial population.
Topics: Bacterial Adhesion; Carbohydrate Sequence; Dental Plaque; Humans; Molecular Sequence Data
PubMed: 8462782
DOI: 10.1096/fasebj.7.5.8462782 -
Journal of Bacteriology Nov 1992We cloned and sequenced the Prevotella loescheii gene plaA, which encodes a lectin-like adhesin that mediates the coaggregation of P. loescheii 1295 with Streptococcus... (Comparative Study)
Comparative Study
We cloned and sequenced the Prevotella loescheii gene plaA, which encodes a lectin-like adhesin that mediates the coaggregation of P. loescheii 1295 with Streptococcus oralis 34. A probe derived from the N-terminal amino acid sequence of the purified adhesin was used to identify the plaA gene from a P. loescheii genomic library constructed in lambda GEM-11. Sequence analysis of plaA indicates that the initial translation product contains a 22-amino-acid leader. The reading frame of the plaA gene is interrupted after amino acid 28 of the mature protein by a TAA termination codon. Amplification of the P. loescheii genomic DNA in the region surrounding this codon by the polymerase chain reaction followed by DNA sequencing of the cloned DNA fragment established that this stop codon was not an experimental artifact. A frameshift beginning 29 bp downstream of the ochre terminator was required to access the only large open reading frame in the gene. Amino acid sequences of six purified peptides derived by limited proteolysis of adhesin with endoproteinase Lys-C matched the downstream amino acid sequence derived by translation of the large open reading frame. The gene coding sequence of 2.4 kb contains sufficient information for the synthesis of an 89-kDa protein. A putative rho-independent terminator (delta G = -25.5 kcal/mol [ca. -107 kJ/mol]) was detected 38 bp downstream from the plaA stop codon.
Topics: Adhesins, Bacterial; Amino Acid Sequence; Bacterial Adhesion; Bacterial Proteins; Bacteroides; Base Sequence; Blotting, Southern; Calorimetry; Cloning, Molecular; Codon; DNA, Bacterial; Escherichia coli; Frameshift Mutation; Genes, Bacterial; Genomic Library; Lectins; Molecular Sequence Data; Molecular Weight; Oligonucleotide Probes; Open Reading Frames; Plasmids; Protein Conformation; Restriction Mapping; Sequence Homology, Amino Acid; Terminator Regions, Genetic
PubMed: 1429455
DOI: 10.1128/jb.174.22.7328-7336.1992 -
Oral Microbiology and Immunology Oct 1992Various gram-negative anaerobic bacterial species can be detected in the oral flora of edentulous infants. However, knowledge of the initial infection source is still...
Various gram-negative anaerobic bacterial species can be detected in the oral flora of edentulous infants. However, knowledge of the initial infection source is still scarce. Thirty Caucasian mothers (mean age 30 years) and their edentulous infants (mean age 3 months) were examined for the possible similarity of the oral gram-negative anaerobic flora. Paraffin-stimulated saliva was collected from the mothers. A pooled swab sample from mucosal surfaces and unstimulated saliva were collected from the infants. The samples were inoculated on nonselective and selective media and cultured aerobically and anaerobically. All of the 30 mothers harbored Fusobacterium nucleatum and 29 mothers Prevotella melaninogenica in their saliva. The salivary levels of P. melaninogenica, F. nucleatum, nonpigmented Prevotella spp., Prevotella intermedia and Prevotella loescheii exceeded 10(4) CFU/ml in about half of the 30 mothers. At this maternal salivary level, the infants' colonization frequency of P. melaninogenica and F. nucleatum was doubled. A positive correlation between maternal salivary concentration and infant's colonization was found for P. melaninogenica. No positive association was found with nonpigmented Prevotella spp., P. intermedia and P. loescheii. It can be speculated that maternal saliva may act as a source of some gram-negative anaerobes in the oral microflora of edentulous infants as early as before tooth eruption.
Topics: Adult; Bacterial Infections; Bacteroidaceae; Bacteroides; Capnocytophaga; Colony Count, Microbial; Female; Fusobacterium nucleatum; Gram-Negative Anaerobic Bacteria; Humans; Infant; Mother-Child Relations; Mouth Mucosa; Saliva
PubMed: 1494450
DOI: 10.1111/j.1399-302x.1992.tb00587.x