Development of a novel PCR method to comprehensively analyze salivary bacterial flora and its application to patients with odontogenic infections.
ABSTRACT The objective of this study was to develop a novel polymerase chain reaction (PCR) method to comprehensively analyze salivary bacterial flora.
The bacterial flora in the saliva of 10 healthy persons and 11 patients with odontogenic infections were examined using a DNA extraction method with a high level of cell destruction efficiency and a novel universal primer set to amplify approximately 580 bp of the 16S rDNA sequence.
Streptococcus (54.5%), Neisseria (14.7%), Actinomyces (8.4%), Gemella (4.1%), Granulicatella (3.8%), and Prevotella (1.4%) were dominant in a total of 1655 clones examined from the saliva of the healthy subjects. The dominant genera differed among the patients with odontogenic infections (a total of 823 clones) and were entirely different from those of the healthy subjects.
This novel comprehensive salivary bacterial flora analysis method may be a useful supportive method to identify causative agents of odontogenic infections.
- SourceAvailable from: ncbi.nlm.nih.gov[show abstract] [hide abstract]
ABSTRACT: A relatively wide range of bacteria have been isolated from root canals using standard culture techniques. However, only 50% of the bacteria in the oral cavity are cultivable (S. S. Socransky et al., Arch. Oral Biol. 8:278-280, 1963); hence, bacterial diversity in endodontic infections is underestimated. This study used a PCR-based 16S rRNA gene assay, followed by cloning and sequencing of 16S rRNA amplicons from a small subset of samples to assess the diversity of bacteria present in infected root canals. A total of 41 clinical samples from 15 de novo and 26 refractory cases of endodontic infections were assessed. Of these samples, 44% were positive by culture and 68% were positive by PCR. Eight samples were selected for further analysis. Of these, the two de novo cases yielded sequences related to those of the genera Enterococcus, Lactobacillus, Propionibacterium, and Streptococcus and two clones were related to previously uncultivated bacteria, while the sinus-associated, de novo case yielded sequences related to those of the genera Lactobacillus, Pantoea, Prevotella, and Selenomonas. The five refractory cases produced clones which were related to the genera Capnocytophaga, Cytophaga, Dialister, Eubacterium, Fusobacterium, Gemella, Mogibacterium, Peptostreptococcus, Prevotella, Propionibacterium, Selenomonas, Solobacterium, Streptococcus, and Veillonella and two clones representing previously uncultivated bacteria. The phylogenetic positions of several clones associated with the Clostridiaceae and Sporomusa subgroups of the Firmicutes grouping are also shown. This study demonstrates that molecular techniques can detect the presence of bacteria in endodontic infections when culture techniques yield a negative result and can be used to identify a wider range of endodontic-infection-related bacteria including the presence of previously unidentified or unculturable bacteria.Journal of Clinical Microbiology 10/2001; 39(9):3282-9. · 4.07 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The purpose of this investigation was to compare characteristics of patients hospitalized with odontogenic infections during the 1980s to those of the 1990s. This study was a retrospective record review that compared 2 cohorts of patients admitted to the same institution during two 81-month periods, one decade apart. Admission criteria were face or neck swelling suggesting abscess or cellulitis and one or more of the following: temperature above 38 degrees C, white blood cell (WBC) count greater than 10.8 x 10(3)/microL, or concern about airway compromise. Characteristics reviewed were age, gender, race, admission temperature, admission WBC count, fascial space(s) involved, tooth of etiology, duration of hospitalization, and bacteria isolated. Data were compared for statistical significance (P <.05). No significant differences were found between the 2 cohorts for age, gender, race, admission temperature, admission WBC count, space involvement, or length of stay (P <.05). One tooth (mandibular left first molar) of 52 was involved more frequently in the 1990 group (P <.03). Gram-positive cocci were isolated significantly more frequently from the 1990s patients than from the 1980s patients (P <.03). There were also significant differences (P <.02) between cohorts in the isolation frequency of individual genera, such as alpha-hemolytic Streptococci, coagulase negative staphylococci, Staphylococcus epidermidis, Bacteroides melanogenicus, beta-lactamase positive Bacteroides, Eikenella corrodens, and Neisseria species. Eighty-one percent of the bacteria cultured from the 1990s patients were resistant to one or more common antibiotics; 47% of these organisms were Staphylococcus aureus. No clinically significant differences existed in the characteristics of patients hospitalized with odontogenic infections between the 1980s and the 1990s. Although there were differences in the type and prevalence of bacteria isolated, this was probably a result of changes in nomenclature, identification protocols, and isolation techniques.Journal of Oral and Maxillofacial Surgery 07/2001; 59(7):739-48; discussion 748-9. · 1.33 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: 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.International Journal of Oral Surgery 11/1981; 10(5):313-22.