Antimicrobial resistance in dentistry

Efficacy of antimicrobials in preventing resistance in solid organ transplant recipients: A systematic review of clinical trials

BACKGROUND

In the absence of effective antimicrobials, transplant surgery is not viable, and antirejection immunosuppressants cannot be administered, as resistant infections compromise the life-saving goal of organ transplantation.

AIM

To evaluate the efficacy of antimicrobials in preventing resistance in solid organ transplant recipients.

METHODS

A systematic review was conducted using a search methodology consistent with the preferred reporting items for systematic reviews and meta-analyses. This review included randomized clinical trials that evaluated the efficacy of antimicrobial agents (prophylactic or therapeutic) aimed at preventing antimicrobial resistance. The search strategy involved analyzing multiple databases, including PubMed/MEDLINE, Web of Science, Embase, Scopus, and SciELO, as well as examining gray literature sources on Google Scholar. A comprehensive electronic database search was conducted from the databases' inception until May 2024, with no language restrictions.

RESULTS

After the final phase of the eligibility assessment, this systematic review ultimately included 7 articles. A total of 2318 patients were studied. The most studied microorganisms were cytomegalovirus, although vancomycin-resistant enterococci, Clostridioides difficile, and multidrug-resistant Enterobacterales were also analyzed. The antimicrobials used in the interventions were mainly maribavir, valganciclovir, ganciclovir, and colistin-neomycin. Of concern, all clinical trials showed significant proportions of resistant microorganisms after the interventions, with no statistically significant differences between the groups (mean resistance 13.47% vs 14.39%), except for two studies that demonstrated greater efficacy of maribavir and valganciclovir (mean resistance 22.2% vs 41.1% in the control group; P < 0.05). The total reported deaths in three clinical trials were 75, and there were 24 graft rejections in two studies.

CONCLUSION

All clinical trials reported significant proportions of antimicrobial-resistant microorganisms following interventions. More high-quality randomized clinical trials are needed to corroborate these results.

Antimicrobial resistance in patients with endodontic infections: A systematic scoping review of observational studies

The aim of this study was to assess the prevalence and proportions of antimicrobial-resistant species in patients with endodontic infections. A systematic scoping review of scientific evidence was accomplished involving different databases. Nine investigations were selected including 651 patients. Enterococcus faecalis was resistant to tetracycline (30%-70%), clindamycin (100%), erythromycin (10%-20%), ampicillin (9%) and azithromycin (60%). On the contrary, Prevotella spp., Fusobacterium spp., Peptostreptococcus spp. and Streptococcus spp. were resistant to penicillin, tetracycline, doxycycline, ciprofloxacin, amoxicillin, erythromycin, metronidazole and clindamycin in different proportions. Fusobacterium nucleatum showed high resistance to amoxicillin, amoxicillin plus clavulanate and erythromycin. Prevotella oralis presented a predisposition to augment its resistance to clindamycin over time. Tanerella forsythia exhibited resistance to ciprofloxacin and rifampicin. Lactococcus lactis presented robust resistance to cephalosporins, metronidazole, penicillin, amoxicillin and amoxicillin-clavulanic acid. It was observed high levels of resistance to antimicrobials that have been utilised in the local and systemic treatment of oral cavity infections.

Microbial resistance to oral antiseptics used in hospitalized patients: A systematic scoping review of randomized clinical trials

AIMS

To evaluate the prevalence and proportions of bacteria resistant to oral antiseptics used in hospitalized patients.

METHODS AND RESULTS

A review of randomized clinical trials (RCTs) was led by implementing the PRISMA extension for scoping reviews including various databases. MeSH terms and keywords were used to assess only RCTs with antiseptic-resistant outcomes. Fourth RCTs met the selection criteria. These trials studied 399 hospitalized patients for respiratory infections or cardiovascular disease. Methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii were predominant pathogens in the chlorhexidine group. It was found that Veillonella parvula and Campylobacter gracilis (57% of the isolates) had resistance to triclosan, while 67% of Pseudomonas, Acinetobacter, and Enterobacter species presented resistance to chlorhexidine. However, an increase in minimal inhibitory concentrations of triclosan or chlorhexidine during the follow-up period was not observed. Moreover, chlorhexidine reduced the amount of S. aureus in dental plaque and the oropharyngeal colonization by aerobic microorganisms; nonetheless, it was unsatisfactory to decrease the occurrence of respiratory infections. No adverse events were reported.

CONCLUSIONS

Resistance of V. parvula and C. gracilis to triclosan, and Pseudomonas, Acinetobacter, and Enterobacter species to chlorhexidine were perceived. However, these resistances did not increase during the follow-up period.

Bacterial resistance to antiseptics used in dentistry: A systematic scoping review of randomized clinical trials

OBJECTIVES

To evaluate the prevalence and proportions of bacteria resistant to antiseptics used in dentistry.

METHODS

A review of randomized clinical trials (RCTs) was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for scoping reviews involving different databases. MeSH terms and keywords were provided to examine only RCTs with antiseptic-resistant results.

RESULTS

Five RCTs were included. These investigations analysed 442 patients. Concerning the prevalence and proportion of species resistant to antiseptics, it was found that the chlorhexidine group showed a statistically significant increase in Streptococcus mutans and Lactobacillus acidophilus counts indicating bacterial resistance (p < 0.001). Moreover, Veillonella species showed resistance to triclosan at the commencement and during the RCTs, and a slight increase in the proportion of resistant strains was observed. Porphyromonas gingivalis, Staphylococcus aureus, and Pseudomonas aeruginosa did not show resistance to cetylpyridinium chloride. Similarly, it was no observed resistance to medicinal herbal plant formulations.

CONCLUSIONS

Resistance of S. mutans and L. acidophilus to chlorhexidine was observed, this resistance increased during the follow-up period. Similarly, although in a slight proportion, an increase in the resistance of Veillonella spp. to triclosan during the study period was also described. No microorganisms resistance was observed to any of the other antiseptics studied.

Antibiotic Resistance in Patients with Peri-Implantitis: A Systematic Scoping Review

The implementation of adjunctive antibiotics has been recommended for the therapy of peri-implantitis (PI). In this review, antibiotic resistance patterns in PI patients were assessed. A systematic scoping review of observational studies and trials was established in conjunction with the PRISMA extension for scoping reviews. The SCOPUS, PubMed/MEDLINE, EMBASE, SCIELO, Web of Science, and LILACS databases were reviewed along with the gray literature. The primary electronic examination produced 139 investigations. Finally, four observational studies met the selection criteria. These studies evaluated 214 implants in 168 patients. Porphyromonas gingivalis and Fusobacterium nucleatum mainly presented high resistance to tetracycline, metronidazole, and erythromycin in PI patients. Similarly, Aggregatibacter actinomycetemcomitans was also highly resistant to clindamycin and doxycycline. Other microorganisms such as Tannerella forsythia, Parvimonas micra, and Prevotella intermedia/nigrescens also presented significant levels of resistance to other antibiotics including amoxicillin, azithromycin, and moxifloxacin. However, most microorganisms did not show resistance to the combination amoxicillin metronidazole. Although the management of adjunctive antimicrobials in the therapy of PI is controversial, in this review, the resistance of relevant microorganisms to antibiotics used to treat PI, and usually prescribed in dentistry, was observed. Clinicians should consider the antibiotic resistance demonstrated in the treatment of PI patients and its public health consequences.