Susceptibility of oral obligate anaerobes to telithromycin, moxifloxacin and a number of commonly used antibacterials

Periodontal microbiology and microbial etiology of periodontal diseases: Historical concepts and contemporary perspectives

This narrative review summarizes the collective knowledge on periodontal microbiology, through a historical timeline that highlights the European contribution in the global field. The etiological concepts on periodontal disease culminate to the ecological plaque hypothesis and its dysbiosis-centered interpretation. Reference is made to anerobic microbiology and to the discovery of select periodontal pathogens and their virulence factors, as well as to biofilms. The evolution of contemporary molecular methods and high-throughput platforms is highlighted in appreciating the breadth and depth of the periodontal microbiome. Finally clinical microbiology is brought into perspective with the contribution of different microbial species in periodontal diagnosis, the combination of microbial and host biomarkers for this purpose, and the use of antimicrobials in the treatment of the disease.

The pathogenic microbial flora and its antibiotic susceptibility pattern in odontogenic infections

Suppurative head and neck infections of odontogenic origin are the most frequent type of head and neck infections. According to the literature, 7-10% of all antibiotics are currently prescribed for their treatment. Since penicillin was invented, the overall antibiotic sensitivity and resistance pattern of the isolated pathogenic microflora has continuously changed. The response of microorganisms to antibiotics and the development of resistance to their action is a purely evolutive process characterized by genetic mutations, acquisition of genetic material or alteration of gene expression and metabolic adaptations. All this makes challenging and difficult the correct choice of empirical antibiotic treatment for head and neck space infections even today. The aim of this paper was to evaluate the literature and to evidence the most frequent locations of odontogenic head and neck infections, the dominant pathogenic microbial flora, the genetic mutations and metabolic changes necessary for bacteria in order to aquire antibiotic resistance and as well its susceptibility and resistance to common antibiotics. We also aimed to highlight the possible changes in bacterial resistance to antibiotics over time, and to assess whether or not there is a need for fundamental changes in the empirical antibiotic treatment of these infections and show which these would be.

Comparing the Antimicrobial In Vitro Efficacy of Amoxicillin/Metronidazole against Azithromycin-A Systematic Review

On account of its proven clinical efficacy, the combination of systemically administered amoxicillin and metronidazole is frequently adjuncted to non-operative periodontal therapy and well documented. Potential drawbacks of this regimen, e.g., side effects and problems with the compliance, led to an ongoing search for alternatives. Azithromycin, an antibiotic extensively used in general medicine, has recently found its niche in periodontal therapy as well. This systematic review aimed to analyze the in vitro antimicrobial efficacy of amoxicillin plus metronidazole versus azithromycin. For this purpose, a systematic literature search was performed, and studies published up to 29 March 2018 referenced in Medline, Embase, Cochrane, and Biosis were independently screened by two authors. An additional hand search was performed and studies focusing on the evaluation of in vitro antimicrobial efficacy of amoxicillin + metronidazole or azithromycin on bacteria from the subgingival biofilm were included. English and German language research reports were considered. From 71 identified articles, only three articles were eligible for inclusion. These studies showed heterogeneity in terms of analytical methods and strains explored. However, all studies used multispecies biofilm models for analysis of the antimicrobial activity. Unanimously, studies reported on more pronounced antimicrobial effects when applying the combination of amoxicillin + metronidazole, compared to azithromycin. Based on the few studies available, the combination of amoxicillin + metronidazole seemed to display higher antimicrobial efficacy in vitro than azithromycin.

Determination and identification of antibiotic-resistant oral streptococci isolated from active dental infections in adults

OBJECTIVE

To determine and identify antibiotic-resistant bacteria (ARB) of oral streptococci from active dental infections in adults and its association with age and gender.

MATERIAL AND METHODS

This cross-sectional study included 59 subjects from 18 to 62 years old. Ninety-eighth samples obtained from the subjects were cultivated in agar plates containing antibiotics amoxicillin/clavulanic acid (A-CA), clindamycin, and moxifloxacin (concentrations of 16, 32 or 64 µg/ml). PCR assay was performed to identify bacterial species.

RESULTS

The bacterial species that showed more antibiotic-resistance (AR) was S. mutans (45.9%), followed by S. gordonii (21.6%), S. oralis (17.6%), S. sanguinis (9.5%), S. salivarius (5.4%) and S. sobrinus (0%). Moreover, clindamycin (59.4%) showed the highest frequency of AR. Moxifloxacin and A-CA showed an susceptibility >99.1%, while clindamycin showed the lowest efficacy (93.3%); there was a significant statistically difference (p < .01). The age group between 26 and 50 years old (32.2%) and females (28.8%) showed more multiresistance. Clindamycin showed a statistical difference (p < .05) when comparing groups by gender.

CONCLUSIONS

Clindamycin was the antibiotic with the highest frequency of ARB and lower bactericidal effect. Moxifloxacin and A-CA showed the highest efficacy and the lowest ARB frequency. Streptococcus mutans was the bacterial specie that showed an increased frequency of AR.

Systemic moxifloxacin vs amoxicillin/metronidazole adjunct to non-surgical treatment in generalized aggressive periodontitis

Background

The objective of this randomized clinical study was to evaluate the effect of systemic administration of moxifloxacin compared to amoxicillin and metronidazole, combined with non-surgical treatment in patients with generalized aggressive periodontitis (GAgP) in a 6-month follow-up.

Material and Methods

A total of 39 systemically healthy patients with GAgP were evaluated in this randomized clinical trial. Periodontal parameters were recorded at the baseline during the 1st, 3rd and 6th month. Patients received either 400 mg of moxifloxacin per os once daily or 500 mg of metronidazole and 500 mg amoxicillin per os three times daily for 7 days consecutively.

Results

No significant differences between groups were found in any parameters at the baseline. Both groups led to a statistically significant decrease in all clinical periodontal parameters compared to the baseline (PI, p<0.001 and GI, PD, BOP, CAL, p<0.01). There were no differences between the 1st and 3rd months or the 3rd and 6th months for clinical parameters in the groups. Also, no intergroup difference was observed in any parameters at any time, except the gingival index at 6th months.

Conclusions

Systemic administration of moxifloxacin as an adjunct to non-surgical treatment significantly improves clinical outcomes and provides comparable clinical improvement with less adverse events to that of combination of amoxicillin and metronidazole in the treatment of GAgP.

Key words: Aggressive periodontitis, amoxicillin, metronidazole, moxifloxacin, nonsurgical periodontal debridement.

Efficacy and safety of adjunctive local moxifloxacin delivery in the treatment of periodontitis

BACKGROUND

Moxifloxacin exerts excellent antibacterial activity against most putative periodontal pathogens and has been shown to kill bacteria in biofilm and host cells.

METHODS

Patients with chronic periodontitis were randomly assigned to receive a single subgingival application of a 0.125%, 0.4%, or 1.25% moxifloxacin gel or placebo gel immediately after full-mouth scaling and root planing (SRP). Clinical efficacy measurements were assessed in sites with baseline probing depth (PD) of ≥5.4 mm at 6 weeks and 3 months and any adverse events were determined. In addition, putative periodontal pathogens and resistance of subgingival bacteria against moxifloxacin were assessed.

RESULTS

Data of 57 patients were included in the statistical analysis. In all treatment groups, the PD decreased from baseline to 3 months, with the greatest reduction seen in patients treated with moxifloxacin 0.4% (1.5 ± 0.6 mm; P = 0.023 compared to placebo), followed by patients receiving moxifloxacin 1.25% (1.2 ± 0.4), moxifloxacin 0.125% (1.1 ± 1.1), and placebo (1.0 ± 0.6). No linear trend for PD reduction with increasing moxifloxacin concentrations was found. Porphyromonas gingivalis showed the greatest reduction in prevalence among the assessed pathogens, without any significant intergroup differences. No correlation or systematic relationship between adverse events, including bacterial resistance against moxifloxacin, and the investigational gels was found.

CONCLUSIONS

In periodontal pockets with PD of ≥5.4 mm, a single subgingival administration of a 0.4% moxifloxacin gel as an adjunct to SRP may result in additional PD reduction compared to SRP alone. In addition, the investigated moxifloxacin gels seem to be safe.

Antibiotic susceptibility and resistance of the odontogenic microbiological spectrum and its clinical impact on severe deep space head and neck infections

OBJECTIVE

The purpose of this retrospective study was to identify the major pathogens responsible for deep space head and neck infections and their current resistance to routinely used antibiotics in a university hospital setting.

STUDY DESIGN

A total of 206 patients suffering from odontogenic deep space infections were treated at our department by means of surgical intervention and intravenous administration of antibiotics.

RESULTS

The predominant bacteria were viridans group streptococci (VGS), staphylococci, Prevotella, Peptostreptococcus, and Bacteroides. In the aerobic spectrum, resistance against clindamycin was found in 18%, against macrolides in 14%, and against penicillin G in 7%. The anaerobes were resistant to clindamycin in 11%, to metronidazole in 6%, and to penicillin G in 8%.

CONCLUSION

The high resistance rate for clindamycin and macrolides was especially striking and may necessitate an adaptation of our antibiotic regime in the future.