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Biomedical subjects

A J van Winkelhoff

Publications and source records attributed to A J van Winkelhoff.

At least 55 records · Page 3Linked to original sources
PubMed1998

Additional clinical and microbiological effects of amoxicillin and metronidazole after initial periodontal therapy.

The aims of this study were to evaluate the clinical and microbiological effects of initial periodontal therapy (IT) and to determine the additional effects of systemic amoxicillin (Flemoxin Solutab) 375 mg TID plus metronidazole 250 mg TID therapy, in patients with adult Actinobacillus actinomycetemcomitans (Aa)-associated periodontitis in conjunction with either Porphyromonas gingivalis (Pg), Bacteroides forsythus (Bf) and/or Prevotella intermedia (Pi). In addition the adverse effects of the antimicrobial therapy were also documented. A total of 22 patients were enrolled. The deepest, bleeding pocket in each quadrant was selected and at these 4 experimental sites clinical measurements and microbiological testing was carried out at baseline, after (IT), i.e., 21 weeks after baseline, and after antimicrobial therapy (AM), i.e., 35 weeks after baseline. At baseline, the mean plaque index (PI) amounted 0.5, 0.1 after IT and 0.3 after systemic AM. The mean bleeding index decreased from 1.6 to 1.2 after IT and a further decrease to 0.7 after AM was noted. Suppuration was completely eliminated after AM. The mean change of probing pocket depth (PPD) after IT amounted 1.4 mm and was further reduced with an additional mean change of 1.1 mm after medication. Clinical attachment gain was 1.1 mm after IT and an additional 0.9 mm was observed after AM. One of the 22 Aa positive patients and 4 of 17 Pg positive patients became negative for these species after IT. The number of patients with detectable Pi decreased from 16 to 10 after IT. After AM, in comparison to baseline, suppression below detection level for Aa was achieved in 19 out of 22, for Pg in 9 out of 17, for Bf in 13 out of 14, and for Pi in 11 out of 16 patients. By contrast, higher frequencies of Peptostreptococcus micros and Fusobacterium nucleatum were found after AM. On the basis of the microbiological results the study group was separated into 2 subgroups: group A consisted of subjects who had no detectable levels of Aa, Pg, Bf and <5% of Pi after AM. Group B consisted of those who still showed presence of one of these 3 species and/or > or =5% levels of Pi. After AM, group B had significantly higher PI, BI, PPD and CAL scores then group A. It is concluded that group A showed low plaque scores and no detectable periodontal pathogens. This microbiological condition has been associated with a long-term stable periodontium.

Actinobacillus Infections↗
PubMed1997

beta-Lactamase producing bacteria in adult periodontitis.

In 23 untreated adult periodontitis patients, the occurrence of beta-lactamase producing periodontal bacteria was determined. In addition to non-selective isolation media, selective isolation and growth of beta-lactamase positive subgingival bacterial species was carried out on blood agar plates supplemented with amoxicillin and plates with amoxicillin+clavulanic acid. Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, Peptostreptococcus micros, Fusobacterium nucleatum, Bacteroides forsythus and Campylobacter rectus isolates from the non-selective medium were tested for beta-lactamase activity by a nitrocefin disk method (DrySlide) and by a laboratory chromogenic nitrocefin-based test. Isolates from the amoxicillin plates that were absent on the amoxicillin/clavulanic acid plates were identified and tested for beta-lactamase production. Based on the non-selective plates, six of 23 P. intermedia isolates, 2 of 19 B. forsythus isolates and 3 of 23 F. nucleatum isolates were beta-lactamase positive. The beta-lactamase positive species Prevotella loescheii, Prevotella buccae, Prevotella buccalis and Actinomyces spp were recovered from the selective amoxicillin plates. beta-Lactamase positive subgingival species were recovered from 17 of 23 patients (74%) but usually comprised low proportions of the subgingival microbiota (range < 0.01-15%). Comparison of the DrySlide test and the nitrocefin-based laboratory test revealed full agreement of test results. beta-Lactamase activity in whole subgingival plaque was detected in 12 patient samples (52%). It was concluded that beta-lactamase activity in subgingival bacteria in adult periodontitis is a common feature. However, since the majority of the samples showed only low-level enzymatic activity, the clinical relevance of this observation with regard to therapy with unprotected enzyme-susceptible beta-lactams is uncertain, though failure on the other hand, is difficult to rule out when a mechanism of resistance is present. The majority of beta-lactamase positive strains was found among species of the Prevotella genus.

Actinomyces↗
PubMed1997

Prevalence and distribution of six capsular serotypes of Porphyromonas gingivalis in periodontitis patients.

Previous reports have described six serotypes based on K antigens in Porphyromonas gingivalis strains. The purpose of the present study was to investigate the prevalence and distribution of these serotypes in 185 patients with P. gingivalis-associated periodontitis. Polyclonal rabbit antisera, raised against each of the different type strains, were used in double-immunodiffusion and immunoelectrophoresis assays. In addition, a subset of 76 strains was investigated for the presence of capsular structures by means of the India ink and Bruce White staining techniques. These strains were also tested for auto-aggregation in phosphate-buffered saline (PBS). All six K serotypes were present in the study sample. In total, 84 (45.4%) patients were colonized with a K-typeable P. gingivalis strain with a predominance of types K5 (12%) and K6 (23.2%). A correlation was found between arbitrary age categories and the prevalence of currently known K serotypes, which were found in 60% of patients aged 12 to 30 years, in 49% of patients aged 31 to 50, and in 25% of patients aged 51 to 70 years. In the subset of 76 P. gingivalis strains, 32 (42.1%) were K-typeable. Fifty-three strains (69.7%) showed microscopic evidence of encapsulation, suggesting the existence of K serotypes other than K1 to K6. Twenty-one strains (27.6%) auto-aggregated in PBS and were not K-typeable, nor did they show any evidence of encapsulation. It was concluded that the majority of clinical P. gingivalis isolates is encapsulated and that encapsulation is associated with the presence of a K antigen. Auto-aggregation seems to be associated with the absence of a capsular structure and, consequently, the absence of a K antigen.

Adolescent↗
PubMed1997

Periodontal bacteria colonizing oral mucous membranes in edentulous patients wearing dental implants.

The purpose of this study was to investigate the prevalence of the microbiota on the oral mucosal surfaces and in the peri-implant pocket in edentulous subjects with a past history of periodontitis. Twenty edentulous subjects wearing dental implants for at least one year and with a history of periodontitis participated in this study. Clinical parameters were assessed (plaque, redness, swelling, peri-implant probing depth [PIPD], and bleeding on probing) and microbiological samples were taken (oral mucosal surfaces, saliva, plaque, and peri-implant pocket). Based on the clinical results, the group as a whole showed healthy peri-implant tissues. A mean PIPD of 3.6 mm was found. A statistically significant correlation was found between the PIPD and bleeding upon probing, plaque scores, redness, and swelling. Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were not detected. The subjects harboring Prevotella intermedia showed presence of PIPD of > or = 5 mm. All subjects harbored Peptostreptococcus spp., Fusobacterium spp., and other Prevotella species. Actinomyces odontolyticus, Bacteroides forsythus, Campylobacter rectus, Pseudomonas spp., and enterobacteria were detected less frequently. Three subjects showed signs of overt soft tissue inflammation. They harbored higher proportions of Peptostreptococcus spp. than the other subjects. The results corroborate the suggestion that the primary source of colonization for dental implants in edentulous patients are the oral mucous membranes. The results indicate that the microbiota of subjects wearing dental implants with a past history of periodontitis are composed of bacteria associated with a healthy periodontium or gingivitis. It is suggested that elimination of the subgingival environment by extraction of all natural teeth probably initiates the disappearance of the two periodontal bacteria A. actinomycetemcomitans and P. gingivalis.

Actinomyces↗
PubMed1997

Systemic antibiotic therapy in severe periodontitis.

The main goal in the treatment of periodontitis is to control the subgingival infection. Systemic periodontal antibiotic therapy aims to reinforce mechanical debridement procedures and to support the host defense system in overcoming the infection that remains after conventional mechanical treatment. In particular, patients with early onset periodontitis and patients with refractory periodontitis may benefit from systemic antimicrobial therapy. Outside clinical parameters, the use of microbiologic information can assist in selecting the most optimal antibiotic regimen based on the presence and levels of selected periodontal pathogens.

Administration, Oral↗
PubMed1996

Novel polysaccharide capsular serotypes in Porphyromonas gingivalis.

Recently van Winkelhoff et al. (1) described 3 novel serotypes in virulent Porphyromonas gingivalis strains, which were based on different polysaccharide antigens. These antigens probably represent capsular structures and have been designated K1, K2 and K3. In the present study we report on 3 novel capsular serotypes, which are represented by P. gingivalis strains ATCC 49417, HG 1690 and HG 1691. The strains, isolated from patients with periodontitis, showed obvious encapsulation in wet India ink preparations. Thermostable antigens could be detected in the supernatant fractions of autoclaved cells. These antigens appeared to be negatively charged, sensitive to periodate degradation, and resistant to proteinase K treatment. On the basis of these characteristics we conclude that the antigens are probably extra-cellular polysaccharides representing a bacterial capsular structure. These K-antigens did not cross-react with K1, K2 or K3 immune-sera of P. gingivalis, with the exception of the K2 antiserum, which partially recognized K5- and K6-antigens. In contrast, K5 and K6 antisera did not react with the K2-antigen. After absorbtion of the K2 antiserum with cells of strains HG 1690 (K5) and HG 1691 (K6) cross-reactivity was no longer present. We propose these novel serotypes to be designated: K4 (ATCC 49417), K5 (HG 1960) and K6 (HG 1691).

Adult↗
PubMed1996

The effect of periodontal treatment on periodontal bacteria on the oral mucous membranes.

The aim of this study was to investigate the effect of conventional periodontal treatment on the prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia on oral mucous membranes in patients with periodontitis. Fifteen patients were selected with moderate to severe periodontitis (mean age: 39.8 years, range: 26 to 58). From each patient the 4 deepest sites with bleeding on probing were selected for clinical and microbiological evaluation. At baseline, 6 weeks after oral hygiene instruction and extensive scaling and root planing, and 3 months after periodontal surgery, clinical parameters and microbiological samples including saliva, oral mucous membranes, and supra- and subgingival plaque were evaluated for the presence of the 3 test bacteria using indirect immunofluorescence. All clinical variables, except redness, showed a significant improvement after surgery. After treatment, the subgingival prevalence of the 3 putative periodontal pathogens had decreased significantly. However, almost no concomitant reduction in the prevalence of the bacteria was seen on the oral mucous membranes. This suggests that the oral mucous membranes may serve as a source for reinfection of the periodontium after treatment.

Adult↗
PubMed1995

Metronidazole susceptibility factors in Actinobacillus actinomycetemcomitans.

Actinobacillus actinomycetemcomitans is a facultative anaerobic bacterium that displays moderate susceptibility to metronidazole and this study was undertaken to identify the factors involved. A. actinomycetemcomitans appeared two to four times less susceptible to metronidazole when grown in air supplemented with 5% CO2 than under anaerobic conditions. Ferredoxin-linked pyruvate:oxidoreductase activity was absent but each strain exhibited nitroreductase activity which corresponded directly with uptake of metronidazole and susceptibility to the drug under anaerobic conditions but not in air supplemented with 5% CO2. Nitroreductase activity therefore appears responsible for the susceptibility of A. actinomycetemcomitans to metronidazole.

4-Aminobenzoic Acid↗
PubMed1995

Putative periodontal pathogens colonizing oral mucous membranes in denture-wearing subjects with a past history of periodontitis.

The prevalence of selected putative periodontal pathogens colonizing oral mucous membranes was investigated in 26 denture-wearing subjects with a history of periodontitis. The microbiota of the oral cavity of these subjects was examined on average 9.3 years after extraction (range: 1-40 years). Samples were taken from several locations on the oral mucous membranes, from saliva and from plaque attached to the upper and lower denture. Actinobacillus actinomycetemcomitans was not detected in any of the 26 edentulous subjects. Porphyromonas gingivalis was detected in 2 subjects (proportion of cultivable flora: 0.002% and 12.5%). Prevotella intermedia was recovered from 7 subjects with a mean proportion of 0.5% (range < 0.001%-6.3%). Analysis showed that subjects harbouring P. intermedia were wearing full dentures for a longer period of time (mean: 20.2 years) than subjects in which P. intermedia could not be detected (mean: 6.6 years). This result suggests that the absence of P. intermedia shortly after extraction may reflect only a temporary event. Other Prevotella species were found in 22 subjects, constituting < 2% of the total cultivable flora (range 0.01%-10.5%). In conclusion, the low prevalence of P. gingivalis and the absence of A. actinomycetemcomitans, suggest that the oral cavity of edentulous subjects may not be regarded as a habitat for these species. The preferable habitat of the Prevotella spp. seems to be the oral mucous membranes, possibly with the exception of P. intermedia.

Adult↗
PubMed1995

Temperate bacteriophages are common among Actinobacillus actinomycetemcomitans isolates from periodontal pockets.

Actinobacillus actinomycetemcomitans is a suspected etiologic agent in destructive periodontal diseases. The detection of bacteriophages in A. actinomycetemcomitans in the subgingival plaque of patients with rapidly destructive forms of periodontitis led to the hypothesis that bacteriophage infection might increase the virulence of this bacterium (19). A. actinomycetemcomitans was isolated from 68 subjects from the Netherlands and Switzerland with localized juvenile periodontitis, rapidly progressing periodontitis, or adult periodontitis, and was tested for the presence of temperate bacteriophage with the overlay plate technique. More than half of the A. actinomycetemcomitans strains were found to release bacteriophage which formed individual plaques on indicator strains. Electron microscopy of preparations from 7 strains revealed virions with an icosahedral head and a contractile tail typical for double-stranded DNA bacteriophages. The presence of A. actinomycetemcomitans carrying temperate bacteriophage was not correlated with the composition of the subgingival microflora nor with the clinical form of periodontal disease. Destructive periodontal disease of subjects with phage-carrying A. actinomycetemcomitans was not more severe than of subjects with phage-free A. actinomycetemcomitans as determined by several clinical parameters. In contrast, the pocket depth and the attachment loss were significantly lower for adult periodontitis subjects with phage-carrying A. actinomycetemcomitans. It seems unlikely that the frequently occurring temperate bacteriophages increase significantly the virulence of A. actinomycetemcomitans.

Adult↗
PubMed1994

Amoxycillin causes an enhanced uptake of metronidazole in Actinobacillus actinomycetemcomitans: a mechanism of synergy.

We investigated the influence of sub-inhibitory concentrations amoxycillin on metronidazole uptake of the metronidazole-susceptible facultative microorganism Actinobacillus actinomycetemcomitans. The rate of metronidazole uptake by bacterial cells simultaneously incubated with amoxycillin was higher than uptake in cells incubated with metronidazole alone. This phenomenon may explain the recently reported in-vitro synergic interaction between metronidazole and amoxycillin against A. actinomycetemcomitans.

Aggregatibacter actinomycetemcomitans↗
PubMed1994

Microbiological and clinical effects of metronidazole and amoxicillin in Actinobacillus actinomycetemcomitans-associated periodontitis. A 2-year evaluation.

In this study, we evaluated the microbiological and clinical effects of mechanical debridement in combination with metronidazole and amoxicillin therapy in 48 patients with Actinobacillus actinomycetemcomitans-associated periodontitis, 3 months and at least 24 months after active treatment. The results of this study showed that 47 out of 48 patients were still negative for A. actinomycetemcomitans subgingivally, at the mucous membranes, the tonsillar area and in the saliva, 2 years after therapy. The clinical results showed that a reduction of probing pocket depth, probing attachment level, bleeding index and plaque index was not only seen in the time between baseline and 3 months after therapy, but further clinical improvement was observed between 3 and 24 months after active treatment. We conclude that combined mechanical debridement and metronidazole plus amoxicillin therapy is very effective in suppressing A. actinomycetemcomitans below cultivable levels over a long period of time, suggesting elimination of this organism, and that recolonization of A. actinomycetemcomitans seems to be a rare event. The elimination of A. actinomycetemcomitans is paralleled by a further improvement of the periodontal status of the patients, even up to 24 months after active treatment.

Aggregatibacter actinomycetemcomitans↗
PubMed1994

Quantitative aspects of the subgingival distribution of Actinobacillus actinomycetemcomitans in a patient with localized juvenile periodontitis.

The subgingival microflora in a patient with localized juvenile periodontitis was studied. Of the 97 sites investigated, 28 (29%) showed attachment loss. A correlation was found between the number of Actinobacillus actinomycetemcomitans cells and the clinical attachment level and probing pocket depth. Of the 97 test sites, 70 (73%) were positive for A. actinomycetemcomitans. Of the total number of A. actinomycetemcomitans cells isolated from this patient, more than 99% were found at sites with attachment loss, < 1% being present at sites without attachment loss. The mean percentage of A. actinomycetemcomitans was 21.2% at sites with attachment loss and 0.45% at sites without attachment loss. The distribution of Porphyromonas gingivalis showed a symmetrical pattern, being present at the 1st molar and 2nd premolar sites in all quadrants and at the lower incisor sites. This species was absent at multiple sites showing overt attachment loss.

Adult↗
PubMed1994

Short-term effect of full-mouth extraction on periodontal pathogens colonizing the oral mucous membranes.

In this study, we investigate the prevalence of selected periodontal pathogens on the oral mucous membranes before and after full-mouth tooth extractions in patients with severe periodontitis. 8 patients were microbiologically examined 2 x before and 2 x after extraction; several locations on the oral mucous membranes, saliva, supra- and subgingival plaque, were sampled. Besides their presence in subgingival plaque, we detected before extraction on the mucous membranes Actinobacillus actinomycetemcomitans in 2 patients (mean 0.03%), Porphyromonas gingivalis in 6 patients (mean 9%), and Prevotella intermedia (mean 2%) and other Prevotella species (mean 7%) in all patients. At 1 and 3 months after extraction, A. actinomycetemcomitans and P. gingivalis could not be detected in any of these patients on the oral mucous membranes and in saliva, while from all patients still P. intermedia (mean 3%) and the other blackpigmented Prevotella species (mean 4%) could be isolated. These results indicate that the preferable habitat for A. actinomycetemcomitans and P. gingivalis is dental plaque in subgingival lesions. P. intermedia and the other blackpigmented Prevotella species can colonize the oral mucous membranes of edentulous patients irrespective of the presence of a subgingival microflora. We speculate that in periodontal patients the colonization of mucous membranes with P. gingivalis and A. actinomycetemcomitans is transient in nature and most likely the result of dissemination from the subgingival microflora. Thus it seems unlikely that edentulous patients constitute a reservoir of infection of P. gingivalis A. actinomycetemcomitans.

Adolescent↗
PubMed1994

Comparison of six typing methods for Actinobacillus actinomycetemcomitans.

Actinobacillus actinomycetemcomitans is an important pathogen in the etiology of severe periodontitis. For epidemiological studies on the prevalence of certain pathogenic clones and transmission of this bacterium, adequate typing methods are necessary. The purpose of this study was to compare six different typing methods for A. actinomycetemcomitans. Five reference strains and 27 fresh clinical isolates from periodontitis patients were used. Serotyping showed 12 serotype a strains, 13 type b strains, 6 type c strains, and 1 nontypeable strain. Biotyping on the basis of the fermentation of mannose, mannitol, and xylose resulted in six biotypes. Antibiogram typing was evaluated by measuring the inhibition zones of seven antibiotics in agar diffusion tests. With this method eight main types which could be further differentiated into 15 subtypes were found. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns of outer membrane proteins were similar among all isolates tested. Restriction endonuclease analysis (REA) of whole chromosomal DNA resulted in five main types. These five main types were further differentiated into 24 subtypes on the basis of DNA fragment differences in the high-molecular-weight region. Hybridization of DNA fragments with ribosomal DNA (ribotyping) resulted in 22 to 24 different types, depending on the restriction endonuclease used. Ribotype patterns were easy to interpret and provided an univocal distinction between different strains compared with REA results. When applied to epidemiologically related isolates, all methods were able to discriminate two clonal types among five isolates from five children from one family. We conclude that serotyping, biotyping, and outer membrane patterns were reproducible but had a low discriminatory potential. REA and ribotyping were reproducible and gave the highest number of distinct types. When the DNA typing methodis were compared, all strains tested could be distinguished. These findings confirm the heterogeneity found within the species A. actinomycetemcomitans.

Aggregatibacter actinomycetemcomitans↗
PubMed1994

[Halitosis (fetor ex ore). A review].

About 15% of the Dutch population has, in a more or lesser degree, complaints about bad breath. This is caused particularly by the anaerobic metabolism of a number of oral microorganisms, in which putrefaction occurs and volatile sulfur compounds will be formed. Some of these compounds are also possibly involved in the pathogenesis of periodontitis. A good oral hygiene is of primary importance to prevent halitosis and to reduce bad breath. Antiseptic mouth-waters can be helpful in the reduction of the bacterial metabolism. In addition, stimulation of the salivary secretion has a dual favourable effect, firstly because of its antimicrobial salivary proteins, and secondly by reduction of the retention of nutrients in the oral cavity.

Bacteria, Anaerobic↗
PubMed1993

Long-standing bacteremia caused by oral Actinobacillus actinomycetemcomitans in a patient with a pacemaker.

A case of symptomatic Actinobacillus actinomycetemcomitans bacteremia in a patient with an implanted pacemaker is presented. Attacks of fever occurred for at least 1 year. Oral examination revealed a mild form of periodontitis. A. actinomycetemcomitans was isolated from several oral sites. DNA fingerprinting of strains from the blood and the oral cavity showed identical profiles. This finding strongly suggests that the oral cavity was the primary source of A. actinomycetemcomitans bacteremia in this case. The patient was treated with the combination of metronidazole plus amoxicillin for 7 days, which resulted in a rapid cure and elimination of A. actinomycetemcomitans from the blood and the oral cavity.

Actinobacillus Infections↗