Identification of four Treponema species in subgingival samples by nested-PCR and their correlation with clinical diagnosis.

The relationship between different species of oral Treponemas and inflammation in periodontal disease progression is complex. The purpose of this study was to analyze and compare the subgingival plaque samples collected from periodontally healthy subjects and from chronic gingivitis and periodontitis patients in order to detect the presence of T. denticola, T. pectinovorum, T. socranskii and T. vincentii using nested-PCR technology. After DNA extraction from the samples using QIAmp DNA Mini Kit (QIAGEN, the four Treponema species were determined with nested-polymerase chain reaction which requires two sets of primers to amplify a specific DNA fragment in two separate runs of PCR. Pearson chi-square was implemented to compare the three groups as to the presence of four Treponema species. Results of this investigation showed significant differences between groups regarding subject proportion of T. denticola, T. socranskii, T. pectinovorum, T. vincentii, with a higher percentage of patients from associated-disease groups of patients harboring these four species than healthy subjects. These differences were more pronounced in presence of Treponema denticola and Treponema socranskii. Our findings suggest that Treponema denticola and Treponema socranskii concurrent presence indicate more accurately the association with chronic gingivitis and periodontitis.

[Prevotella species involved in the onset of superficial face and neck abscesses]. / Specii de Prevotella implicate în producerea abceselor cu localizare în lojile superficiale ale fetei si gâtului.

The aim of the study was to identify at species level the Prevotella strains from 30 pus samples collected by needle aspiration in patients with abscesses of fascial spaces of the face and neck. Microscopy of Gram-stained direct smear and cultures on selective and nonselective media incubated aerobically and anaerobically were performed in each pus specimen. All strains of Gram-negative strictly anaerobic bacilli were identified to genus and species level using conventional methods of diagnosis and the Rapid ID 32 A system (BioMérieux, Marcy-l'Etoile, France). The Prevotella isolates were recovered (alone or in association with other bacteria) in 46.6% of the investigated specimens and were represented in reverse order of frequency by the following species: P. melaninogenica, P. denticola, P. oralis and P. loescheii. In conclusion, the rate of Prevotella isolation was relatively high and the most frequently isolated species was P. melaninogenica (followed by P. denticola), while no P. intermedia was found.

[Phenotypical characterization of some strains of anginosus streptococci isolated from superficial face and neck abscesses]. / Caracterizarea fenotipica a unor tulpini de streptococi din grupul anginosus izolate din abcese cu localizare în lojile superficiale ale fetei si gâtului.

The aim of the present study was to identify at species level and to characterize the strains of streptococci belonging to anginosus group isolated from 30 pus samples collected from patients with abscesses of fascial spaces of the face or neck. The identification of facultatively anaerobic Gram-positive cocci in chains at genus level was made by conventional diagnosis methods and at species level by the help of Rapid ID 32 STREP system. The cultural, biochemical and antigenic (limited at Lancefield Group identification by Slidex Strepto-Kit) characterization was performed in the mean time with the species identification. The anginosus streptococcal strains were isolated either in association with other bacteria or in pure culture and S. anginosus isolates clearly predominated. As expected, the anginosus streptococcal strains were found to be heterogeneous regarding the cultural, biochemical and antigenic features.

[Anaerobic Gram-negative bacilli involved in the etiopathogeny of the abscesses of superficial fascial spaces of the face and neck]. / Bacili Gram-negativi anaerobi implicati in etiopatogenia abceselor cu localizare in lojile superficiale ale fetei si gâtului.

UNLABELLED: The aim of this study was to isolate and identify at species level the strains of anaerobic Gram-negative bacilli (GNB) from pus samples collected in patients with abscesses of fascial spaces of the face and neck. Microscopy of Gram-stained smears and cultures were performed in each specimen. The strictly anaerobic GNB strains were identified using the conventional methods of diagnosis and the Rapid ID 32 A system. In addition, the other strains isolated in association with these bacteria were identified at least to genus level. The 28 anaerobic GNB isolates belonged to: Fusobacterium nucleatum and different species of Prevotella (4 species) and Bacteroides (3 species). CONCLUSIONS: The anaerobic GBN strains were recovered--either alone or in association with other migroorganisms--in more than half of all investigated samples and represented about 40% of all isolates. The most frequently isolated species were P> melaninogenica and B. ureolyticus.

Oral streptococcal strains isolated from odontogenic infections and their susceptibility to antibiotics.

The aim of this study was to identify at species level and to investigate the antibiotic susceptibility of oral streptococcal strains isolated from 100 pus samples collected from Romanian patients with different odontogenic infections. The isolates were identified at species level using the Rapid ID 32 STREP system and their susceptibility was testing by the Etest, against: penicillin G, ampicillin, erythromycin, clindamycin and tetracycline. For the investigation of erythromycin resistance phenotype the disk diffusion test was used. The isolates belonged to several species, with Streptococcus anginosus and Streptococcus oralis predominating. Reduced susceptibility to beta-lactam antibiotics was found only among the isolates belonging to S. mitis and S. sanguinis groups. Resistance to erythromycin was detected among all species, except for: S. constellatus, S. intermedius and S. gordonii, and the M phenotype was established, while resistance to tetracycline was detected within all species but S. gordonii. In contrast, clindamycin was fully active. As most odontogenic infections are mixed infections, often involving strictly anaerobic bacteria, which are frequently beta-lactamase producers, the association of a penicillin and a beta-lactamase inhibitor, like Amoxiclav, is recommended when the antimicrobial treatment is necessary.