Viability of four putative periodontal pathogens and enteric rods in the anaerobic transport medium VMGA III

Activity of pradofloxacin against Porphyromonas and Prevotella spp. Implicated in periodontal disease in dogs: susceptibility test data from a European multicenter study

Collaborating veterinarians from five European countries collected subgingival bacterial samples from dogs exhibiting clinical periodontal disease. Sterile endodontic paper points were used for collection of the samples, which were transported to a central laboratory for susceptibility testing. Anaerobic bacteria were isolated and Porphyromonas and Prevotella isolates identified to the species level; susceptibility to pradofloxacin and metronidazole was determined using the CLSI agar dilution methodology. A total of 630 isolates, 310 of Porphyromonas spp. and 320 of Prevotella spp., were isolated. Pradofloxacin MIC data for all isolates were in the range of < or =0.016 to 1 microg/ml, the overall MIC(50) was 0.062, and the overall MIC(90) was 0.25 microg/ml. There were no differences in activity against Porphyromonas and Prevotella isolates or in the pradofloxacin susceptibility distributions from the different European countries. All isolates were within the wild-type distribution and were fully susceptible to pradofloxacin. Metronidazole was also highly active against these strains: 316 of 320 Prevotella strains (98.8%) and 309 of 310 Porphyromonas strains (99.7%) were susceptible (MICs of < or =8 microg/ml). However, three Prevotella strains had intermediate metronidazole susceptibility (MICs of 16 microg/ml), while one Prevotella and one Porphyromonas strain were metronidazole resistant (MICs of 128 and 256 microg/ml, respectively). Pradofloxacin, a novel broad-spectrum fluoroquinolone, demonstrates a high degree of antianaerobic activity against strains isolated from clinical cases of periodontal disease and shows activity against metronidazole-resistant isolates. The broad-spectrum activity of pradofloxacin makes it a suitable candidate for the treatment of periodontal disease in dogs.

Subgingival microbiota in peri-implant mucosa lesions and adjacent teeth in partially edentulous patients

BACKGROUND

Osseointegrated dental implants have been shown to be a predictable approach to provide the adequate support for the replacement of missing teeth. It has been observed that implants showing signs of peri-implantitis contain subgingival microbiota similar to that around natural teeth with periodontal disease. This study identified the subgingival microbiota around implants with peri-implant lesions and natural teeth in partially edentulous patients.

METHODS

Clinical and radiographic parameters were recorded and microbial samples taken from 16 implants with signs of pocketing, 12 neighboring and 11 non-neighboring teeth to the affected implants in 11 patients and 15 stable implants in eight patients (controls). Samples were cultured using techniques for Enterobacteriaceae spp and facultative/anaerobic periodontal pathogens. Statistical analysis included Friedman test to establish differences between the subgingival microbiota cultured from implants and teeth and two-tailed Mann Whitney test and chi square to find differences in two separate samples (P < or = 0.05).

RESULTS

There were statistical differences between the subgingival microbiota in peri-implant lesions and stable implants for Gram-negative enteric rods (P <0.05). P. gingivalis (1.42%) was detected in peri-implant lesions but not in stable implants. A significant correlation between the subgingival microbiota from implants and neighboring teeth for Gram-negative enteric rods (P = 0.023) and implants and non-neighboring teeth for P. gingivalis (P = 0.042) was found. The frequency detection of Gram-negative enteric rods (75%) and P. intermedia/nigrescens (25%) was higher in peri-implant lesions (P <0.05).

CONCLUSIONS

The subgingival microbiota in peri-implant lesions showed high levels of periodontopathic bacteria and superinfecting bacteria compared to healthy stable implants. The role of superinfecting bacteria in the pathogenesis of peri-implant lesions needs further investigation.

Variabilité de l'efficacité de l'érythromycine et de la spiramycine sur les pathogènes parodontaux dans les parodontites agressives. Étude in vitro comparative

AIMS

Erythromycin (ERY) and spiramycin (SPI) are the most frequently prescribed macrolides by dentists. However, the emergence of resistant anaerobic subgingival bacteria imposes an increased vigilance. This study aims to compare these macrolides efficacy on principal periopathogens.

MATERIALS AND METHODS

Twenty adult patients with aggressive periodontitis were selected and a total of 60 samples were taken from subgingival flora. Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, Peptostreptococcus micros and Actinobacillus actinomycetemcomitans were isolated according to J. Slots's rapid identification method. The susceptibilities to ERY and SPI were studied using disk diffusion susceptibility test and minimum inhibitory concentration test (MIC test).

RESULTS

The efficiency variability of ERY and SPI on the 50 isolated anaerobic periopathogens was present either interindividually (between different patients) and intra-individually (within the same patient). While 68% of the tested anaerobic bacteria were sensitive to SPI (22% resistant), only 54% were sensitive to ERY (34% resistant). Although moderate, the efficacy of SPI seemed more regular in general than ERY: it's variation coefficient (40%) is lower than the ERY one (53%). The 7 A. actinomycetemcomitans tested showed all a high resistance.

CONCLUSION

In a general way, the spectre of activity of SPI is stacked in that of ERY. However, this study shows a better and regular activity of SPI on the main tested periopathogens. These results are in favour of the use of SPI in periodontology when penicillins and doxycycline are not useful because specific problems are identified (allergy, pregnancy...).

Antimicrobial susceptibility variation of 50 anaerobic periopathogens in aggressive periodontitis: an interindividual variability study

BACKGROUND/AIMS

The frequent use of antibiotics in developed countries has led to the emergence of widespread bacterial resistance. In this study, the interindividual variability of the antibiotic susceptibility of 50 putative microorganisms in aggressive periodontitis patients has been evaluated by means of VC (variation coefficient).

MATERIAL AND METHODS

A total of 60 microbial samples were collected from 20 adult patients diagnosed with aggressive periodontitis (2-4 samples by patient). Bacterial strains of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Fusobacterium nucleatum, and Peptostreptococcus micros were isolated according to Slots' rapid identification method. The susceptibilities to 10 antibiotics were studied: penicillin G (PEN), ampicillin (AMP), amoxicillin (AMX), amoxicillin/clavulanate (AMC), tetracycline (TET), doxycycline (DOX), ciprofloxacin (CIP), erythromycin (ERY), spiramycin (SPI) and clindamycin (CLIN), using the Disk Diffusion Susceptibility test (DDS test: Kirby-Bauer's modified method for anaerobic bacteria). The broth microdilution Minimum Inhibitory Concentration test was carried out as a control test.

RESULTS

Among the 50 identified bacteria, 15 were P. gingivalis, 12 P. intermedia, 8 T. forsythia, 9 F. nucleatum, and 6 P. micros. The results of the DDS test show that penicillins (especially AMC, AMP, and AMX), cyclines (especially DOX) and CLIN are highly effective against the 50 anaerobic studied bacteria. CIP and ERY have the lowest efficacy against those bacteria. CIP shows a very variable activity according to anaerobic bacteria species, being particularly inactive against P. gingivalis and very efficient against T. forsythia and P. micros. SPI is also highly efficient but not against P. micros.

CONCLUSIONS

The interindividual susceptibility of principal periodontal pathogens to antibiotics is not homogeneous and seems to vary according to bacterial species and antimicrobial molecules. This variability seems to be greater with older molecules (PEN, TET, ERY) than with more recent ones, which indicates more stable results (AMC, AMX, AMP, and DOX). P. intermedia appeared to be the bacteria most resistant to penicillins and showed the highest coefficient variation. Together with scaling and root planing, the combination of two antibiotics would therefore seem to be recommended in the treatment of aggressive periodontitis, particularly in the presence of P. intermedia.

Yeasts in periodontal pockets

OBJECTIVES

The presence of yeasts in periodontal pockets has been described in a few studies. The association between yeasts and putative periodontal pathogens is not well described. This study aims at assessing the prevalence of yeasts in periodontal pockets and possible associations with the clinical conditions of the sampled sites and other micro-organisms present.

MATERIAL AND METHODS

2 subject groups form the basis for this study. The 1st comprises results from microbiological samples from periodontal pockets of 128 subjects. The 2nd originates from 126 periodontal patients with untreated pockets. Microbiological identification was performed after cultivation on blood and Sabouraud agar plates, and "checkerboard" DNA-DNA hybridisation.

RESULTS

The prevalence of subjects with yeasts in the pockets was 15.6% and 17.5% in the 2 groups respectively and was inconsistent according to gender. No correlation was found between age and the presence of yeasts. Eubacterium saburreum was weakly correlated with presence of yeasts (r=0.194 p=0.03). Yeasts were rarely found in both samples from the same individual.

CONCLUSIONS

Our results indicate that yeasts can be expected to be present in periodontal pockets in one out of 6 periodontal patients independent of gender and age. Eubacterium saburreum seems to occur frequently together with yeasts.

Subgingival microbial profile of Papillon-Lefèvre patients assessed by DNA-probes

The prevalence of 18 selected bacterial species was assessed by means of "checkerboard" DNA-DNA hybridisation in a group of 12 Saudi-Arabian adolescents with Papillon-Lefèvre syndrome. A total of 36 tooth sites were investigated. The patients exhibited severe periodontal disease with deep pockets. All 12 patients harboured the putative bacterial pathogens P. intermedia, F. nucleatum, P. micros and S. intermedius while T. denticola, B. forsythus, P. nigrescens, E. corrodens, S. noxia and C. rectus were recovered from 11 patients. P. gingivalis was recovered from 9 patients and 18 sites while corresponding figures for A. actinomycetemcomitans were 8 and 19, respectively. A number of the investigated species (B. forsythus, T. denticola, P. intermedia, C rectus) reached high levels (> or =10(6) cells) in more than 1/2 of the patients. On the other hand, bacteria such as A. actinomycetemcomitans and P. gingivalis were infrequently encountered at high levels in these subgingival samples. In conclusion, the analysis failed to demonstrate a PLS-specific profile of the subgingival infection, since the bacterial composition of the sampled sites closely resembled that characterising deep pockets in adult periodontitis patients.

Comparison of the subgingival microbiota of periodontally healthy and diseased adults in northern Cameroon

Our study is the 1st report on subgingival microbiota in adult Cameronians. The aim was to investigate, using the checkerboard DNA-DNA hybridization technique, the prevalence of 18 oral species in subgingival plaque samples obtained from sex- and age-matched Cameronian adults with and without periodontal destruction. We also compared cultivation and the Affirm DP test with the checkerboard technique in their capability to detect some selected species among the 18. 21 adult periodontitis patients and 21 periodontally healthy subjects were examined and the results were compared statistically. Each periodontitis patient had at least 4 pockets of > or = 6 mm depth, while the healthy subjects had no sites more than 3 mm deep. Results of the checkerboard analysis showed that significantly (p < 0.05) more periodontitis patients tested positive for most of the 18 bacterial species. The Gram-positive species Actinomyces naeslundii, Streptococcus mitis and Streptococcus sanguis, known as microbiota of healthy sites, were detected significantly more frequently in the healthy group. Cultivation demonstrated P. gingivalis, B. forsythus, A. actinomycetemcomitans, P. intermedia and F. nucleatum in significantly lower %s of patients as compared to the checkerboard technique. Furthermore, the Affirm DP test detected P. gingivalis and B. forsythus in significantly fewer patients than did the checkerboard technique. A. actinomycetemcomitans was detected in 52.3% of the patients by the latter technique while the Affirm DP test failed to detect the bacterium in any of the samples. Overall, the results of the present study confirm the importance of the screening method and indicate that the prevalences of the investigated putative periodontal pathogens and beneficial species in the healthy and diseased adult Cameronians were similar to those reported for adults in the West and in some developing countries.

Prevalence of 6 putative periodontal pathogens in subgingival plaque samples from Romanian adult periodontitis patients

The aim of the present study was to determine by standard cultivation procedures the detection frequencies of Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, and Capnocytophaga species as well as various enteric rods in subgingival plaque samples form Romanian adult periodontitis patients. DNA probe analysis (Affirm DP Microbial Identification Test) was also used, parallel to cultivation, to identify P. gingivalis, A. actinomycetemcomitans, and B. forsythus, in deep (> or = 6 mm) and intermediate (4-5 mm) pockets in some of the subjects investigated. Paper points were used to sample 86 deep pockets in 36 patients and 27 intermediate pockets in 9 of the 36 patients. The chi 2 test was used to test for significance of differences between results obtained by cultivation and DNA analysis in both intermediate and deep pockets. P. gingivalis was recovered in a high percentage of the patients (75.8%) and sites (63.6%) examined, followed by P. intermedia, F. nucleatum, and A. actinomycetemcomitans, respectively. Capnocytophaga species were present in almost all subjects. Enteric rods were recovered in 61.1% of the patients and 55.8% of the sites. Except for this high prevalence of enteric rods, the present group of patients had the periodontal species monitored in %s similar to those commonly perceived in the West. The Affirm DP Test and cultivation showed poor correlation in detecting P. gingivalis, A. actinomycetemcomitans, and B. forsythus. The cultivation prevalence of P. gingivalis and P. intermedia in deep pockets was similar to their prevalence in intermediate ones. Overall, the prevalence of the periodontal pathogens investigated in the present Romanian periodontitis patients is similar to what has been revealed in matching Norwegian and other Western periodontitis patient populations. The high prevalence of enteric rods in the Romanian patients may have been an artifact resulting from prolonged transport of the samples in VMGA III.