Antimicrobial susceptibility profile of clinically relevant Bacteroides, Phocaeicola, Parabacteroides and Prevotella species, isolated by eight laboratories in the Netherlands.

OBJECTIVES: Recently, reports on antimicrobial-resistant Bacteroides and Prevotella isolates have increased in the Netherlands. This urged the need for a surveillance study on the antimicrobial susceptibility profile of Bacteroides, Phocaeicola, Parabacteroides and Prevotella isolates consecutively isolated from human clinical specimens at eight different Dutch laboratories. METHODS: Each laboratory collected 20-25 Bacteroides (including Phocaeicola and Parabacteroides) and 10-15 Prevotella isolates for 3 months. At the national reference laboratory, the MICs of amoxicillin, amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem, metronidazole, clindamycin, tetracycline and moxifloxacin were determined using agar dilution. Isolates with a high MIC of metronidazole or a carbapenem, or harbouring cfiA, were subjected to WGS. RESULTS: Bacteroides thetaiotaomicron/faecis isolates had the highest MIC90 values, whereas Bacteroides fragilis had the lowest MIC90 values for amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem and moxifloxacin. The antimicrobial profiles of the different Prevotella species were similar, except for amoxicillin, for which the MIC50 ranged from 0.125 to 16 mg/L for Prevotella bivia and Prevotella buccae, respectively. Three isolates with high metronidazole MICs were sequenced, of which one Bacteroides thetaiotaomicron isolate harboured a plasmid-located nimE gene and a Prevotella melaninogenica isolate harboured a nimA gene chromosomally.Five Bacteroides isolates harboured a cfiA gene and three had an IS element upstream, resulting in high MICs of carbapenems. The other two isolates harboured no IS element upstream of the cfiA gene and had low MICs of carbapenems. CONCLUSIONS: Variations in resistance between species were observed. To combat emerging resistance in anaerobes, monitoring resistance and conducting surveillance are essential.

[A renewed focus on extra-oral manifestations of oral infections]. / Hernieuwde aandacht voor extraorale gevolgen van ontstekingen in de mond.

Dental focal infections are extraoral manifestations caused by oral pathogens. Pathological oral conditions, such as periapical inflammation and periodontitis, can cause bacteremia. Dissemination of oral pathogens to nonoral sites can subsequently cause infections in extraoral tissues and organs. Cardiovascular infections and brain abscesses are the most common of these. The course of such infections can be lethal. In order to improve patient care, a closer collaboration between dental and medical caregivers is necessary.

[Medicines and oral health care 2. An optimised antibiotic policy in the interest of the patient]. / Medicamenten en mondzorg 2. Een geoptimaliseerd antibioticabeleid in het belang van de patiënt.

Treatment of infectious diseases is complex and success is dependent upon a number of factors. The proper prescription and correct dosage of antimicrobials are important elements in this respect. Incorrect prescription and insufficient dosage can result not only in treatment failure but also contribute to the development of antimicrobial resistance. In order to achieve correct antibiotic dosages it is necessary to gain insight in pharmacokinetic and pharmacodynamic principles. It is also vital to differentiate among various types of infections and to adjust antibiotic prescription to the clinical situation of the individual patient accordingly. To further optimise antibiotic policy collaboration between dental and medical professions is of major importance.

Chromosome instability predicts the progression of premalignant oral lesions.

OBJECTIVES: One of the main problems in reducing the incidence of oral squamous cell carcinoma (OSCC) is the inability to appropriately deal with leukoplakia. Accurately identifying lesions which will progress to malignancy is currently not possible. The present study aims to establish the value of chromosome instability (CI) detection by DNA image cytometry and FISH analysis for prognosis and monitoring of oral leukoplakia. MATERIALS AND METHODS: For this purpose, we included from our archives 102 oral leukoplakia cases, which had been diagnosed between 1991 and 2008. Patient follow-up data were collected and the histopathological diagnosis was revised. CI assessment was carried out on paraffin-embedded tissue sections using both DNA image cytometry (ICM) and dual target FISH for chromosomes 1 and 7. RESULTS: 16 of 102 Patients developed carcinoma in situ or OSCC. Both detection methods were found to yield prognostic information independent of the histopathological diagnosis. CI was a strong individual marker of progression, with hazard ratios (HRs) of 7.2 and 6.8 for ICM and FISH respectively. Moreover, this approach seems suitable for monitoring lesions over time (especially ICM). Combining histopathology and CI enables subdivision of patients into three risk groups, with different probabilities of malignant progression. CONCLUSION: CI detection seems a reliable method for risk assessment of oral premalignancies and its application may contribute to a better risk-counselling and appropriate treatment regimen or watchfull-waiting approach of patients.

Early secondary closure of alveolar clefts with mandibular symphyseal bone grafts and beta-tri calcium phosphate (beta-TCP).

Alveolar reconstruction of bony defects in cleft lip and palate patients is a widely accepted treatment regimen for which multiple donor sites can be used. For 25 years, autogeneous bicortical mandibular symphyseal bone grafts have been used at the authors' centre. In cases in which the alveolar defect was too large to match the volume of the mandibular symphyseal bone transplant, beta-TCP granules were packed against the bone transplant to fill the defect completely. In a retrospective study, 18 patients, who were treated with mandibular symphyseal bone wrapped in beta-TCP granules, were compared with 29 patients, who were treated with mandibular symphyseal bone only. To assess alveolar height, occlusal radiographs were taken directly postoperatively and 1 year later. Mean alveolar bone loss was calculated and compared between groups using Student's t-test and linear regression analysis. No statistically significant difference in alveolar height was found between the two groups. It was concluded that mandibular symphyseal bone grafts enriched with beta-TCP granules can be used successfully in cases in which the alveolar cleft is too large to be grafted with mandibular symphyseal bone alone.

No high-risk HPV detected in SCC of the oral tongue in the absolute absence of tobacco and alcohol--a case study of seven patients.

INTRODUCTION: In recent years, there has been an increase in the number of patients with squamous cell carcinoma (SCC) of the mobile tongue in the absence of tobacco and alcohol. The literature suggests that human papilloma virus (HPV) may be involved in the development of SCC of the head and neck, especially in non-smoking and non-drinking patients. In the oral cavity, however, the presence of the HPV genome has been reported with various percentages. This may be due to misclassification of the oropharyngeal tongue as oral cavity subsite and the use of various detection methods. MATERIALS AND METHODS: Therefore, we evaluated the role of HPV in seven consecutive non-smoking and non-drinking patients (2003-2006) with a SCC located at the oral, mobile tongue using in situ hybridization and SPF(10)Line Blot 25 polymerase chain reaction assays. RESULTS: No HPV was detected in these specimens. To further determine whether a relationship exists between HPV and SCC in the absence of tobacco and alcohol, subsequent studies at specific locations are necessary.