Weichteilinfektionen in der Mund-, Kiefer- und Plastischen Gesichtschirurgie

Molecular Genetic Analysis of Perioperative Colonization by Infection-Related Microorganisms in Patients Receiving Intraoral Microvascular Grafts

Background/Objectives: In oral and maxillofacial surgery, the reconstruction of defects often involves the transfer of skin tissue into the oral cavity utilizing microvascular grafts. This study investigates postoperative changes in microbial colonization following intraoral microvascular transplantation, as well as potential influencing factors. Methods: In 37 patients undergoing intraoral reconstructions, pre- and postoperative swabs were taken from the donor and recipient regions to quantify the seven selected marker bacteria using TaqMan PCRs. Patient-specific factors and clinical data were also recorded. Results: The infection-associated Acinetobacter baumannii tended to decrease postoperatively, while the infectious pathogens Pseudomonas aeruginosa, Enterococcus faecalis and the family of Enterobacteriaceae showed a postoperative increase without being directly associated with a clinical infection. Streptococcus mitis showed a significant postoperative decrease on buccal mucosa and increase on the graft surface (oral dysbiosis) and was significantly reduced or displaced by other bacteria (e.g., Mycoplasma salivarium, positive selection) when treated with ampicillin/sulbactam. Conclusions: The cutaneous microbiome of the graft adapts to the local intraoral environment. Postoperative shifts in oral bacterial colonization and an increase in infection-relevant bacteria were observed. These perioperative changes in colonization are also influenced by the administration of ampicillin/sulbactam. Consequently, single doses of antibiotics appear to be more beneficial compared to longer-term preventive use.

Sonication versus the conventional method for evaluation of the dental microbiome: a prospective pilot study

Objectives

To investigate sonication as a new tool in microbiological probing of dental infections.

Methods

Comparison of a standard probing method: intraoperative swab, with sonication, and vortex of the removed tooth, was performed on 20 carious destructed teeth. Illumina high throughput sequencing of the 16S-rRNA-gene was used for assessing the microbial composition. Antibiotic susceptibility has been assigned based on known resistances of each detected species. Probing procedures were compared using Bland–Altmann-Test, and antibiotic susceptibility using the Friedmann-Test and alpha-adjusted post-hoc-analysis.

Results

In total, 60 samples were analysed: 20 intraoperative swabs, 20 vortex fluids, and 20 sonication fluids. Sonication fluid yielded the highest number of bacterial sequencing reads in all three procedures. Comparing the operational taxonomic units (OTUs) of the identified bacteria, significantly more OTUs were found in sonication fluid samples. Phylum and order abundances varied between the three procedures. Significantly more Actinomycetales have been found in sonication fluid samples compared to swab samples. The assigned resistance rates for the identified bacteria (1.79–31.23%) showed no differences between the tested probing procedures. The lowest resistance rates were found for amoxicillin + clavulanate (3.95%) and levofloxacin (3.40%), with the highest in amoxicillin (30.21%) and clindamycin (21.88%).

Conclusions

By using sonication on extracted teeth, it is possible to get a more comprehensive image of the residing microbial flora compared to the standard procedure. If sonication is not available, vortexing is a potential alternative. In immunocompromised patients, especially when actinomycosis is suspected, sonication should be considered for a more detailed microbiological evaluation of the potential disease-causing microbiome. Due to the high rates of antibiotic resistance, a more targeted antibiotic therapy is favourable. Levofloxacin should be considered as a first-line alternative to amoxicillin + clavulanate in patients with an allergy to penicillin.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02374-0.

Clinical Relevance of the Microbiome in Odontogenic Abscesses

Simple Summary

Odontogenic infections are very common. The course of disease ranges from mild to severe and sometimes even life-threatening infections. Optimal therapy is based on rapid abscess incision and, especially in severe cases, on adjuvant antibiotic therapy that ideally targets the culprit bacteria. In order to identify these bacteria, clinicians usually perform cultural analysis from smears of pus and aim for antibiotic susceptibility testing. In recent years, using new molecular methods, it has become possible to carry out a much more detailed analysis of the bacterial colonization of different parts of the human body by determining a microbiome. In our study, we have, for the first time, compared such a microbiome of odontogenic abscesses with cultural bacterial determination carried out in the clinical routine of a university hospital. The key finding of the study is not only that considerably more bacteria can be detected in the abscess in this way but also that easily cultivated bacteria dominate over the actual fastidious pathogenic bacteria. Thus, routine clinical culture probably only provides a distorted picture of reality and should be supplemented by molecular methods in the future.

Abstract

Odontogenic abscesses are usually caused by bacteria of the oral microbiome. However, the diagnostic culture of these bacteria is often prone to errors and sometimes fails completely due to the fastidiousness of the relevant bacterial species. The question arises whether additional pathogen diagnostics using molecular methods provide additional benefits for diagnostics and therapy. Experimental 16S rRNA gene analysis with next-generation sequencing (NGS) and bioinformatics was used to identify the microbiome of the pus in patients with severe odontogenic infections and was compared to the result of standard diagnostic culture. The pus microbiome was determined in 48 hospitalized patients with a severe odontogenic abscess in addition to standard cultural pathogen detection. Cultural detection was possible in 41 (85.42%) of 48 patients, while a pus-microbiome could be determined in all cases. The microbiomes showed polymicrobial infections in 46 (95.83%) cases, while the picture of a mono-infection occurred only twice (4.17%). In most cases, a predominantly anaerobic spectrum with an abundance of bacteria was found in the pus-microbiome, while culture detected mainly Streptococcus, Staphylococcus, and Prevotella spp. The determination of the microbiome of odontogenic abscesses clearly shows a higher number of bacteria and a significantly higher proportion of anaerobes than classical cultural methods. The 16S rRNA gene analysis detects considerably more bacteria than conventional cultural methods, even in culture-negative samples. Molecular methods should be implemented as standards in medical microbiology diagnostics, particularly for the detection of polymicrobial infections with a predominance of anaerobic bacteria.

Microbiome of Odontogenic Abscesses

Severe odontogenic abscesses are regularly caused by bacteria of the physiological oral microbiome. However, the culture of these bacteria is often prone to errors and sometimes does not result in any bacterial growth. Furthermore, various authors found completely different bacterial spectra in odontogenic abscesses. Experimental 16S rRNA gene next-generation sequencing analysis was used to identify the microbiome of the saliva and the pus in patients with a severe odontogenic infection. The microbiome of the saliva and the pus was determined for 50 patients with a severe odontogenic abscess. Perimandibular and submandibular abscesses were the most commonly observed diseases at 15 (30%) patients each. Polymicrobial infections were observed in 48 (96%) cases, while the picture of a mono-infection only occurred twice (4%). On average, 31.44 (±12.09) bacterial genera were detected in the pus and 41.32 (±9.00) in the saliva. In most cases, a predominantly anaerobic bacterial spectrum was found in the pus, while saliva showed a similar oral microbiome to healthy individuals. In the majority of cases, odontogenic infections are polymicrobial. Our results indicate that these are mainly caused by anaerobic bacterial strains and that aerobic and facultative anaerobe bacteria seem to play a more minor role than previously described by other authors. The 16S rRNA gene analysis detects significantly more bacteria than conventional methods and molecular methods should therefore become a part of routine diagnostics in medical microbiology.

Calculated parenteral initial treatment of bacterial infections: Infections in the ear, nose, throat and mouth and jaw area

This is the sixth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The chapter deals with the antibacterial treatment of more severe infections of the ear, the nose, the throat and the maxillofacial region, including odontogenic and salivary gland infections.

Indication for an additional postoperative antibiotic treatment after surgical incision of serious odontogenic abscesses

INTRODUCTION

Serious abscesses of an odontogenic origin occur frequently in the oral and maxillofacial surgery departments. Rapid surgical incision and drainage constitutes the most important therapeutic action. However, additional surgical therapy and supplementary administration of antibiotics is often carried out, such that the efficiency of this supplementary therapeutic option has been questioned.

METHODS

All patients with severe odontogenic infections who received surgical treatment under general anaesthesia were recruited to this retrospective study. We determined whether they received additional antibiotic therapy on the ward and if it was possible to improve therapeutic outcomes using this option.

RESULTS

A total of 258 patients with a severe odontogenic infection between January 2008 and August 2014 were included. The most frequent infection observed was a submandibular abscess (56%), followed by a perimandibular abscess (18%) and a submental abscess (9%). About 65% of the patients were treated with antibiotics in addition to surgery. The median CRP level prior to surgical treatment was 87.8 mg/l (Q₁: 40.3 mg/l; Q₃: 143.5 mg/l) in patients who were administered an additional antibiotic and 83.8 mg/l (Q₁: 37.3 mg/l; Q₃: 135.0 mg/l) in those who received no antibiotic treatment after surgery. The postoperative median CRP levels were 116.5 mg/l (Q₁: 52.1 mg/l; Q₃: 159.3 mg/l) and 106.5 mg/l (Q₁: 40.6 mg/l; Q₃: 152.6 mg/l), respectively. Neither the preoperative CRP level (p = 0.546) nor the postoperative CRP level (p = 0.450) differed significantly between the groups. But patients who received additional antibiotic therapy had a significantly longer hospital stay (median: 6 days; range: 1-22 days) than patients who had no additional antibiotic therapy (median: 4 days; range: 1-19 days) (p = 0.002).

CONCLUSIONS

This study did not show an improvement in the therapeutic outcome with administration of supplementary antibiotics in addition to surgery. Thus, surgically incising an abscess is the most important therapeutic action and administration of antibiotics must be critically scrutinised.

Teicoplanin versus vancomycin for proven or suspected infection

BACKGROUND

Vancomycin and teicoplanin are commonly used to treat gram-positive infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA). There is uncertainty regarding the effects of teicoplanin compared to vancomycin on kidney function with some previous studies suggesting teicoplanin is less nephrotoxic than vancomycin.

OBJECTIVES

To investigate the efficacy and safety of vancomycin versus teicoplanin in patients with proven or suspected infection.

SEARCH STRATEGY

We searched the Cochrane Renal Group's Specialised Register, CENTRAL, MEDLINE, EMBASE, reference lists of nephrology textbooks, review articles with relevant studies and sent letters seeking information about unpublished or incomplete studies to investigators involved in previous studies.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in any language comparing teicoplanin to vancomycin for patients with proven or suspected infection.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated methodological quality and extracted data using standardised data extraction forms. Study investigators were contacted for information not available in the original manuscripts. Random effects model was used to estimate the pooled risk ratio (RR) with 95% confidence interval (CI).

MAIN RESULTS

We included 24 studies (2,610 patients) in this review. Teicoplanin reduced the risk of nephrotoxicity compared to vancomycin (RR 0.66, 95% CI 0.48 to 0.90).The effects of teicoplanin or vancomycin were similar for clinical cure (RR 1.03, 95% CI 0.98 to 1.08), microbiological cure (RR 0.98, 95% CI 0.93 to 1.03) and mortality (RR 1.02, 95% CI 0.79 to1.30). Six studies reported no cases of acute kidney injury (AKI) needing dialysis. Adverse events were less frequent with teicoplanin including cutaneous rash (RR 0.57, 95% CI 0.35 to 0.92), red man syndrome (RR 0.21, 95% CI 0.08 to 0.59) and total adverse events (RR 0.73, 95% CI 0.53 to 1.00). A lower risk of nephrotoxicity with teicoplanin was observed in patients either with (RR 0.51, 95% CI 0.30 to 0.88) or without aminoglycosides (RR 0.31, 95% 0.07 to 1.50), and also when vancomycin dosing was guided by serum levels (RR 0.22, 95% CI 0.10 to 0.52).

AUTHORS' CONCLUSIONS

Teicoplanin and vancomycin are both effective in treating those with proven or suspected infection; however the incidence of adverse effects including nephrotoxicity was lower with teicoplanin. There were no cases of AKI needing dialysis. It remains unclear whether the differential effect on kidney function should influence which antibiotic be prescribed, although it may be reasonable to consider teicoplanin for patients at higher risk for AKI needing dialysis.