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Jose F Siqueira - One of the best experts on this subject based on the ideXlab platform.

  • The Microbiota of Acute Apical Abscesses
    Journal of Dental Research, 2020
    Co-Authors: Jose F Siqueira, Isabela N Rocas
    Abstract:

    As the breadth of bacterial diversity in the oral cavity has been deciphered by molecular studies, several newly identified species/phylotypes have emerged as potential pathogens. We hypothesized that many of these species/phylotypes could also be involved with the etiology of endodontic abscesses. Abscess aspirates from 42 persons were analyzed for the presence of 81 species/phylotypes by means of a reverse-capture checkerboard hybridization assay. Associations between the most frequently detected taxa were calculated. The most prevalent taxa were Fusobacterium nucleatum, Parvimonas micra, and Porphyromonas endodontalis. Other frequently found taxa included Olsenella uli, streptococci, Eikenella corrodens, some as-yet-uncultivated phylotypes (Bacteroidetes clone X083 and Synergistes clone BA121), and newly named species (Prevotella baroniae and Dialister invisus). Several positive bacterial associations were disclosed. Findings not only strengthen the association of many cultivable species with abscesses...

  • Viral-bacterial associations in acute apical abscesses.
    Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology, 2011
    Co-Authors: Dennis De Carvalho Ferreira, Isabela N Rocas, Simone S.m. Paiva, Flávia Lima Do Carmo, Fernanda Sampaio Cavalcante, Alexandre S. Rosado, Kátia Regina Netto Dos Santos, Jose F Siqueira
    Abstract:

    Objective Viral-bacterial and bacterial synergism have been suggested to contribute to the pathogenesis of several human diseases. This study sought to investigate the possible associations between 9 candidate endodontic bacterial pathogens and 9 human viruses in samples from acute apical abscesses. Study design DNA extracts from purulent exudate aspirates of 33 cases of acute apical abscess were surveyed for the presence of 9 selected bacterial species using a 16S ribosomal RNA gene-based nested polymerase chain reaction (PCR) approach. Single or nested PCR assays were used for detection of the human papillomavirus (HPV) and herpesviruses types 1 to 8. Results Two-thirds of the abscess samples were positive for at least one of the target viruses. Specifically, the most frequently detected viruses were HHV-8 (54.5%); HPV (9%); and varicella zoster virus (VZV), Epstein–Barr virus (EBV), and HHV-6 (6%). Bacterial DNA was present in all cases and the most prevalent bacterial species were Treponema denticola (70%), Tannerella forsythia (67%), Porphyromonas endodontalis (67%), Dialister invisus (61%), and Dialister pneumosintes (57.5%). HHV-8 was positively associated with 7 of the target bacterial species and HPV with 4, but all these associations were weak. Several bacterial pairs showed a moderate positive association. Viral coinfection was found in 6 abscess cases, but no significant viral association could be determined. Conclusions Findings demonstrated that bacterial and viral DNA occurred concomitantly in two-thirds of the samples from endodontic abscesses. Although this may suggest a role for viruses in the etiology of apical abscesses, the possibility also exists that the presence of viruses in abscess samples is merely a consequence of the bacterially induced disease process. Further studies are necessary to clarify the role of these viral-bacterial interactions, if any, in the pathogenesis of acute apical abscesses.

  • Bacteria in the apical root canal of teeth with primary apical periodontitis
    Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology, 2009
    Co-Authors: Jose F Siqueira, Isabela N Rocas, Flávio R.f. Alves, Marlei Gomes Da Silva
    Abstract:

    Objective Bacteria settled in the apical root canal are in a privileged position to inflict damage to the periradicular tissues. Therefore, the species identified in this region can be of special relevance for the pathogenesis of apical periodontitis. This study investigated the occurrence and levels of several bacterial taxa in the apical root canal of teeth with apical periodontitis. Study design DNA extracts from samples taken from the apical part of the root canal of extracted teeth evincing chronic apical periodontitis lesions served as templates for analysis of the presence and levels of 28 bacterial species/phylotypes using a 16S ribosomal RNA gene–based reverse-capture checkerboard hybridization assay. Results Bacterial DNA was detected in 19 out of 20 samples. Detected taxa included Pseudoramibacter alactolyticus (32%), Bacteroidetes clone X083 (26%), Streptococcus species (21%), Olsenella uli (10.5%), Synergistes clone BA121 (10.5%), Fusobacterium nucleatum (10.5%), Porphyromonas endodontalis (10.5%), Dialister clone BS016 (5%), Filifactor alocis (5%), Parvimonas micra (5%), and Treponema denticola (5%). Of these, only Bacteroidetes clone X083 and Synergistes clone BA121 were found at levels above 10 5 . Conclusion Occurrence of these bacterial taxa in the apical part of infected root canals indicates their potential pathogenetic role in the etiology of apical periodontitis.

  • On the use of denaturing gradient gel electrophoresis approach for bacterial identification in endodontic infections
    Clinical Oral Investigations, 2007
    Co-Authors: Julio C. Machado De Oliveira, Isabela N Rocas, Jose F Siqueira, Tulio G. V. Gama, Raquel S. Peixoto, Alexandre S. Rosado
    Abstract:

    Bacteria in infected root canals of teeth evincing chronic apical periodontitis lesions were identified by a polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE) approach. DNA was extracted from root canal samples, and part of the 16 S rRNA gene of all bacteria was amplified by PCR and separated by DGGE, generating banding patterns representative of the community structure. Twenty visible bands were cut out of the gel, re-amplified, and sequenced to provide identification. Sequencing analysis revealed the presence of both cultivable and as-yet-uncultivated species in the samples analyzed, including representatives of the genera Fusobacterium , Bacteroides , Dialister , Synergistes , Prevotella , Eubacterium and Peptostreptococcus . Unambiguous identification was not always possible and the method’s limitations are discussed. In general, the findings showed that PCR-DGGE can be useful for the identification of both cultivable and as-yet-uncultivated bacteria in endodontic infections.

  • characterization of Dialister species in infected root canals
    Journal of Endodontics, 2006
    Co-Authors: Isabela N Rocas, Jose F Siqueira
    Abstract:

    Abstract Members of the Dialister genus are asaccharolytic obligately anaerobic gram-negative coccobacilli that are culture-difficult or remain uncultivated. Their participation in endodontic infections has been only consistently demonstrated after advent of molecular biology approaches. This study was undertaken to characterize Dialister species in samples from primary endodontic infections using a devised 16S rRNA gene-based group-specific heminested PCR assay followed by sequencing of PCR products. Genomic DNA was isolated directly from clinical samples and used as template for PCR. Amplicons from positive specimens were sequenced and phylogenetically analyzed to determine species identity. Ten of 21 clinical samples yielded sequences with the highest percent similarities to oral Dialister species/phylotypes. Seven sequences were from Dialister invisus , and the other three sequences belonged to Dialister pneumosintes , Dialister oral clone BS095 and Dialister sp. clone IS013B24. Findings demonstrated that different Dialister species can take part in the microbiota associated with apical periodontitis lesions.

Isabela N Rocas - One of the best experts on this subject based on the ideXlab platform.

  • The Microbiota of Acute Apical Abscesses
    Journal of Dental Research, 2020
    Co-Authors: Jose F Siqueira, Isabela N Rocas
    Abstract:

    As the breadth of bacterial diversity in the oral cavity has been deciphered by molecular studies, several newly identified species/phylotypes have emerged as potential pathogens. We hypothesized that many of these species/phylotypes could also be involved with the etiology of endodontic abscesses. Abscess aspirates from 42 persons were analyzed for the presence of 81 species/phylotypes by means of a reverse-capture checkerboard hybridization assay. Associations between the most frequently detected taxa were calculated. The most prevalent taxa were Fusobacterium nucleatum, Parvimonas micra, and Porphyromonas endodontalis. Other frequently found taxa included Olsenella uli, streptococci, Eikenella corrodens, some as-yet-uncultivated phylotypes (Bacteroidetes clone X083 and Synergistes clone BA121), and newly named species (Prevotella baroniae and Dialister invisus). Several positive bacterial associations were disclosed. Findings not only strengthen the association of many cultivable species with abscesses...

  • Viral-bacterial associations in acute apical abscesses.
    Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology, 2011
    Co-Authors: Dennis De Carvalho Ferreira, Isabela N Rocas, Simone S.m. Paiva, Flávia Lima Do Carmo, Fernanda Sampaio Cavalcante, Alexandre S. Rosado, Kátia Regina Netto Dos Santos, Jose F Siqueira
    Abstract:

    Objective Viral-bacterial and bacterial synergism have been suggested to contribute to the pathogenesis of several human diseases. This study sought to investigate the possible associations between 9 candidate endodontic bacterial pathogens and 9 human viruses in samples from acute apical abscesses. Study design DNA extracts from purulent exudate aspirates of 33 cases of acute apical abscess were surveyed for the presence of 9 selected bacterial species using a 16S ribosomal RNA gene-based nested polymerase chain reaction (PCR) approach. Single or nested PCR assays were used for detection of the human papillomavirus (HPV) and herpesviruses types 1 to 8. Results Two-thirds of the abscess samples were positive for at least one of the target viruses. Specifically, the most frequently detected viruses were HHV-8 (54.5%); HPV (9%); and varicella zoster virus (VZV), Epstein–Barr virus (EBV), and HHV-6 (6%). Bacterial DNA was present in all cases and the most prevalent bacterial species were Treponema denticola (70%), Tannerella forsythia (67%), Porphyromonas endodontalis (67%), Dialister invisus (61%), and Dialister pneumosintes (57.5%). HHV-8 was positively associated with 7 of the target bacterial species and HPV with 4, but all these associations were weak. Several bacterial pairs showed a moderate positive association. Viral coinfection was found in 6 abscess cases, but no significant viral association could be determined. Conclusions Findings demonstrated that bacterial and viral DNA occurred concomitantly in two-thirds of the samples from endodontic abscesses. Although this may suggest a role for viruses in the etiology of apical abscesses, the possibility also exists that the presence of viruses in abscess samples is merely a consequence of the bacterially induced disease process. Further studies are necessary to clarify the role of these viral-bacterial interactions, if any, in the pathogenesis of acute apical abscesses.

  • Bacteria in the apical root canal of teeth with primary apical periodontitis
    Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology, 2009
    Co-Authors: Jose F Siqueira, Isabela N Rocas, Flávio R.f. Alves, Marlei Gomes Da Silva
    Abstract:

    Objective Bacteria settled in the apical root canal are in a privileged position to inflict damage to the periradicular tissues. Therefore, the species identified in this region can be of special relevance for the pathogenesis of apical periodontitis. This study investigated the occurrence and levels of several bacterial taxa in the apical root canal of teeth with apical periodontitis. Study design DNA extracts from samples taken from the apical part of the root canal of extracted teeth evincing chronic apical periodontitis lesions served as templates for analysis of the presence and levels of 28 bacterial species/phylotypes using a 16S ribosomal RNA gene–based reverse-capture checkerboard hybridization assay. Results Bacterial DNA was detected in 19 out of 20 samples. Detected taxa included Pseudoramibacter alactolyticus (32%), Bacteroidetes clone X083 (26%), Streptococcus species (21%), Olsenella uli (10.5%), Synergistes clone BA121 (10.5%), Fusobacterium nucleatum (10.5%), Porphyromonas endodontalis (10.5%), Dialister clone BS016 (5%), Filifactor alocis (5%), Parvimonas micra (5%), and Treponema denticola (5%). Of these, only Bacteroidetes clone X083 and Synergistes clone BA121 were found at levels above 10 5 . Conclusion Occurrence of these bacterial taxa in the apical part of infected root canals indicates their potential pathogenetic role in the etiology of apical periodontitis.

  • On the use of denaturing gradient gel electrophoresis approach for bacterial identification in endodontic infections
    Clinical Oral Investigations, 2007
    Co-Authors: Julio C. Machado De Oliveira, Isabela N Rocas, Jose F Siqueira, Tulio G. V. Gama, Raquel S. Peixoto, Alexandre S. Rosado
    Abstract:

    Bacteria in infected root canals of teeth evincing chronic apical periodontitis lesions were identified by a polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE) approach. DNA was extracted from root canal samples, and part of the 16 S rRNA gene of all bacteria was amplified by PCR and separated by DGGE, generating banding patterns representative of the community structure. Twenty visible bands were cut out of the gel, re-amplified, and sequenced to provide identification. Sequencing analysis revealed the presence of both cultivable and as-yet-uncultivated species in the samples analyzed, including representatives of the genera Fusobacterium , Bacteroides , Dialister , Synergistes , Prevotella , Eubacterium and Peptostreptococcus . Unambiguous identification was not always possible and the method’s limitations are discussed. In general, the findings showed that PCR-DGGE can be useful for the identification of both cultivable and as-yet-uncultivated bacteria in endodontic infections.

  • characterization of Dialister species in infected root canals
    Journal of Endodontics, 2006
    Co-Authors: Isabela N Rocas, Jose F Siqueira
    Abstract:

    Abstract Members of the Dialister genus are asaccharolytic obligately anaerobic gram-negative coccobacilli that are culture-difficult or remain uncultivated. Their participation in endodontic infections has been only consistently demonstrated after advent of molecular biology approaches. This study was undertaken to characterize Dialister species in samples from primary endodontic infections using a devised 16S rRNA gene-based group-specific heminested PCR assay followed by sequencing of PCR products. Genomic DNA was isolated directly from clinical samples and used as template for PCR. Amplicons from positive specimens were sequenced and phylogenetically analyzed to determine species identity. Ten of 21 clinical samples yielded sequences with the highest percent similarities to oral Dialister species/phylotypes. Seven sequences were from Dialister invisus , and the other three sequences belonged to Dialister pneumosintes , Dialister oral clone BS095 and Dialister sp. clone IS013B24. Findings demonstrated that different Dialister species can take part in the microbiota associated with apical periodontitis lesions.

Ana Paula Vieira Colombo - One of the best experts on this subject based on the ideXlab platform.

  • suppuration associated bacteria in patients with chronic and aggressive periodontitis
    Journal of Periodontology, 2013
    Co-Authors: Carina M Silvaboghossian, Aline Borburema Neves, Fatima A R Resende, Ana Paula Vieira Colombo
    Abstract:

    Background: Suppuration (SUP) on probing may be an indication of active periodontal breakdown. The aim of the present study is to analyze which subgingival species are associated with SUP in patients with chronic (CP) and aggressive (AgP) periodontitis.Methods: A total of 156 patients with CP and 66 with AgP were submitted to full-mouth periodontal examination and subgingival biofilm sampling (14 sites/patient). The counts of 44 bacterial species were determined by checkerboard. Comparisons between groups and sites were analyzed by the Mann-Whitney and Wilcoxon tests, respectively. Associations between frequency of SUP and bacterial species were analyzed by the Spearman correlation coefficient.Results: The prevalence of SUP in patients with CP was 24.4%, and in patients with AgP it was 30.3%, and the percentage of SUP sites in the groups was 5.72% ± 1.06% and 6.96% ± 1.70%, respectively (P >0.05). SUP sites from patients with CP had significantly higher counts of Veillonella parvula, Dialister pneumosinte...

  • detection of Dialister pneumosintes in the subgingival biofilm of subjects with periodontal disease
    Anaerobe, 2007
    Co-Authors: Cintia Tereza Lima Ferraro, Camila Gornic, Adriana Sampaio Barbosa, Rafael Jose Marques Peixoto, Ana Paula Vieira Colombo
    Abstract:

    Dialister pneumosintes has been indicated as a potentially new periodontopathic species. This study evaluated the prevalence of this microorganism in saliva and subgingival biofilm from subjects with different periodontal conditions. Subgingival biofilm and saliva samples from 48 subjects with periodontal health (PH) and 116 patients with chronic periodontitis (CP) were obtained. DNA was extracted from the samples and the presence of D. pneumosintes was determined by PCR. Differences in clinical parameters and frequency of D. pneumosintes between groups were sought by Mann–Whitney, Chi-square and Fisher's exact tests. Overall, D. pneumosintes was detected in 47.8% of the biofilm samples, but only in 3% of saliva samples. CP patients presented a significantly greater mean prevalence of this species in sites with periodontal health and periodontal infection (43.5±7.4% and 62.1±6.4%, respectively) than PH subjects (29.4±7.9%) (Mann–Whitney; p<0.01). Moreover, significant associations between the prevalence of D. pneumosintes and pocket depth (p=0.001), attachment loss (p=0.001) and bleeding on probing (GLM, p=0.014) were observed after adjusting for age and gender. These findings corroborate the association of D. pneumosintes with periodontitis.

  • Detection of Dialister pneumosintes in the subgingival biofilm of subjects with periodontal disease.
    Anaerobe, 2007
    Co-Authors: Cintia Tereza Lima Ferraro, Camila Gornic, Adriana Sampaio Barbosa, Rafael Jose Marques Peixoto, Ana Paula Vieira Colombo
    Abstract:

    Abstract Dialister pneumosintes has been indicated as a potentially new periodontopathic species. This study evaluated the prevalence of this microorganism in saliva and subgingival biofilm from subjects with different periodontal conditions. Subgingival biofilm and saliva samples from 48 subjects with periodontal health (PH) and 116 patients with chronic periodontitis (CP) were obtained. DNA was extracted from the samples and the presence of D. pneumosintes was determined by PCR. Differences in clinical parameters and frequency of D. pneumosintes between groups were sought by Mann–Whitney, Chi-square and Fisher's exact tests. Overall, D. pneumosintes was detected in 47.8% of the biofilm samples, but only in 3% of saliva samples. CP patients presented a significantly greater mean prevalence of this species in sites with periodontal health and periodontal infection (43.5±7.4% and 62.1±6.4%, respectively) than PH subjects (29.4±7.9%) (Mann–Whitney; p

Helene Marchandin - One of the best experts on this subject based on the ideXlab platform.

  • antimicrobial susceptibilities and clinical sources of Dialister species
    Antimicrobial Agents and Chemotherapy, 2007
    Co-Authors: Florent Morio, Helene Jeanpierre, L Dubreuil, Estelle Jumasbilak, L Calvet, Gregoire Mercier, R Devine, Helene Marchandin
    Abstract:

    Seventy-four strains representing the four species of the genus Dialister were isolated from various clinical samples. Dialister pneumosintes and Dialister micraerophilus were the two mainly encountered species. Fifty-five isolates were tested against 14 antimicrobial agents. Decreased susceptibilities to piperacillin, metronidazole, macrolides, fluoroquinolones, and rifampin were demonstrated. The clinical impact of these decreased susceptibilities remains to be investigated but should prompt microbiologists to perform antimicrobial susceptibility testing for clinically important Dialister spp.

  • Dialister micraerophilus sp nov and Dialister propionicifaciens sp nov isolated from human clinical samples
    International Journal of Systematic and Evolutionary Microbiology, 2005
    Co-Authors: Estelle Jumasbilak, Florent Morio, Helene Jeanpierre, Jeanphilippe Carlier, Corinne Teyssier, Kathryn Bernard, Josiane Campos, Helene Marchandin
    Abstract:

    Seventeen anaerobic, Gram-negative, tiny coccobacilli were collected in France from various human clinical samples. Biochemical analyses as well as molecular studies, including 16S rRNA and dnaK gene sequencing, affiliated all the isolates to the genus Dialister. However, 16S rRNA and dnaK gene sequence similarities were below 95·2 and 79·7 %, respectively, when comparisons were performed with the currently described species Dialister pneumosintes and Dialister invisus. Two clusters consisting of 13 and four isolates could be differentiated. 16S rRNA- and dnaK-based phylogeny confirmed that these two clusters represent two novel and distinct lineages within the genus Dialister. Finally, phenotypic, genotypic and phylogenetic data supported the proposal of the two novel species Dialister micraerophilus sp. nov. (type strain ADV 04.01T=AIP 25.04T=CIP 108278T=CCUG 48837T) and Dialister propionicifaciens sp. nov. (type strain ADV 1053.03T=AIP 26.04T=CIP 108336T=CCUG 49291T). The G+C content of the DNA of the D. micraerophilus type strain is 36·3 mol%. On the basis of 16S rRNA gene sequence analysis, 11 isolates originating from Canada could also be affiliated to D. micraerophilus sp. nov., and were included in the species description.

William G Wade - One of the best experts on this subject based on the ideXlab platform.

  • Molecular and Cultural Analysis of the Microflora Associated with Endodontic Infections
    Journal of Dental Research, 2020
    Co-Authors: Mark A Munson, T. Pitt-ford, Bun San Chong, Andrew J. Weightman, William G Wade
    Abstract:

    Cultural studies have indicated that a subset of the oral microflora is responsible for endodontic infections. Approximately 50% of oral bacteria are unculturable, so it is likely that currently unknown bacteria are present in such infections. In this study, cultural and molecular analyses were performed on the microflora in aspirate samples collected from 5 infected root canals. 16S rDNA sequences from 261 isolates and 624 clones were identified by comparison with database sequences. Sixty-five taxa were identified, of which 26 were found by the molecular method alone. A mean of 20.2 taxa was found in each sample. A new species of Dialister was the only organism present in all 5 samples. Twenty-seven novel taxa were detected, 18 of which belonged to the phylum Firmicutes and 8 to Bacteroidetes. Culture-independent, molecular analysis has revealed a more diverse microflora associated with endodontic infections than that revealed by cultural methods alone.

  • Dialister invisus sp nov isolated from the human oral cavity
    International Journal of Systematic and Evolutionary Microbiology, 2003
    Co-Authors: Julie Downes, Mark A Munson, William G Wade
    Abstract:

    Six strains of anaerobic, Gram-negative coccobacilli isolated from the root canals of patients with endodontic infections (five strains) and from a deep periodontal pocket (one strain) were subjected to a comprehensive range of phenotypic and genetic tests and were found to comprise a homogeneous group. Following 16S rRNA gene sequence analysis, they were found to be most closely related to Dialister pneumosintes, with 93 % sequence similarity between the two taxa. A novel species, Dialister invisus sp. nov., is proposed. Biochemically, the species is largely unreactive and is asaccharolytic, with only traces of acetate and propionate detected as metabolic end-products. The G+C content of the DNA of D. invisus strains is 45–46 mol%. The type strain is E7.25T (=CCUG 47026T=DSM 15470T).

  • Characterisation of Eubacterium-like strains isolated from oral infections
    Journal of Medical Microbiology, 2001
    Co-Authors: Julia Downes, Mark A Munson, David A. Spratt, Eija Kononen, Eveliina Tarkka, Hannele Jousimies-somer, William G Wade
    Abstract:

    The genus Eubacterium currently includes a heterogeneous group of gram-positive, non-spore-forming anaerobic bacilli, many of which are slow growing, fastidious and generally unreactive in biochemical tests. As a consequence, cultivation and identification of isolates are difficult and the taxonomy of the group remains indifferent. In this study, 105 isolates from odontogenic infections, infections associated with dental implants or saliva from healthy subjects and provisionally assigned to the genus Eubacterium were subjected to phenotypic and genotypic analysis. Ninety-one of the isolates were identified as belonging to one of 14 previously described species: Atopobium parvulum (5 isolates), A. rimae (29), Bulleidia extructa (2), Cryptobacterium curtum (1), Dialister pneumosintes (1), Eubacterium saburreum (2), E. sulci (8), E. yurii subsp. yurii (1), Filifactor alocis (3), Lactobacillus uli (1), Mogibacterium timidum (13), M. vescum (6), Pseudoramibacter alactolyticus (6) and Slackia exigua (13). The remaining 14 isolates did not correspond to existing species. This study confirms the diversity of organisms provisionally assigned to the genus Eubacterium by conventional identification methods. This group of organisms is frequently isolated from oral infections but their role in the aetiology of these conditions has yet to be determined.