RESUMO
BACKGROUND: In recent years, culture-independent molecular techniques have been developed to investigate microbiota considered uncultivable. However, the data in the literature suggest that molecular techniques and cultural methods target different spectra of bacteria. The objective of this pilot study was to search for not yet identified oral species in the peri-implant and sub-gingival microbiota in patients without signs of oral pathologies, through the use of the culturomics approach, which has never been used before in dentistry. METHODS: Four patients were enrolled; from each patient, samples of sub-gingival and peri-implant plaque were taken and analysed by culturomics. RESULTS: Of 48 isolated species, only 30 had been previously identified by metagenomics in other studies; on the contrary, 12 species had never been associated with the oral cavity before, and 5 of them had never been isolated from clinical specimens. CONCLUSIONS: By adopting culturomics in dentistry, it could be possible to identify a large amount of fastidious microorganisms that inhabit the oral cavity and to more accurately characterize the microorganisms that lead to periodontitis and peri-implantitis. This evidence could represent an important step forward for the diagnosis and treatment of peri-implantitis, as well as a very useful means for the characterization of new potential aetiologic agents.
RESUMO
BACKGROUND AND OBJECTIVES: Infections caused by resistant bacteria are a growing public health problem that is linked to many different causes, among them the antibiotics' incorrect use plays an important role. According to the World Health Organization (WHO) the most dangerous behaviors are the early interruption of antibiotic therapy and the use of molecules without appropriate prescription. The authors conducted a systematic review to assess if antibiotic prescription with different regimens is connected to the onset of bacterial resistance. METHODS: The authors performed an electronic and manual literature search on four databases (Web of Science, Scopus, PubMed, and Cochrane Register of Controlled Trials) from their inception to 15 June 2019. The date of the last search was 27 November 2019. Any article comparing cultural or genic analysis of resistance in patients that took antibiotics with at least two different regimens was included. No language restrictions were applied. Risk of bias for randomized controlled trials (RCTs) was assessed using the Cochrane collaboration's tool whereas case-control and cohort studies were evaluated through the Newcastle-Ottawa scale. RESULTS: The initial search resulted in a total of 1744 titles. After careful evaluation of all results, only three studies satisfied the outcome of the present review. From the qualitative analysis of data, it emerges that even if antibiotics are administered for a shorter period than the conventional one the species that inhabit the oral cavity can adapt quickly and express genes of antibiotic resistance. Additional evidence from this analysis is that not only does the proportion of resistant bacteria increase in the oral cavity, but also in more distant districts such as the intestine. CONCLUSIONS: Despite the great number of studies retrieved by electronic databases only few studies investigated the target of this review. The reason for this evidence is that it is not ethical to investigate and compare different antibiotic regimens, shorter or longer than the appropriate one. This evidence is applicable both to prophylactic administrations and to those aimed at treating infections. Besides this, the WHO affirms that, in the absence of infective complications, the prescription of antibiotic after every type of surgical intervention cannot be admitted and that studies dealing with antibiotic regimens that do not comply with drug's pharmacodynamics characteristics cannot be ethically admitted. PROSPERO acknowledgement of receipt [149149].
RESUMO
Background and objectives: In recent years, many different culture-independent molecular techniques have been developed with the aim of investigating the not yet cultivated part of the resident flora of the oral cavity and of analyzing the peri-implant and periodontal flora both in healthy and diseased sites. The most used technologies are Roche 454 pyrosequencing, Illumina HiSeq/MiSeq, ABI SOLiD and Ion Torrent. Due to these methods, two different approaches are available: Metagenomics and the 16S gene analysis. A complementary strategy was also recently developed: Culturomics. Culturomics consists of different culture conditions that allow a very rapid bacterial identification. The focused question of this review was developed in PICO format in order to investigate the role of metagenomics, 16S gene analysis and culturomics (interventions) in the differential study (comparison) of the peri-implant and periodontal microbiome (outcome) in humans (participants). The secondary aim was the characterization of currents limits and future applications of the three techniques. Methods: The authors performed a literature search on three databases (Web of Science, Scopus and PubMed) from 01/01/2003 to 31/06/2019. Date of last search was: 25/08/19. Any type of article dealing with the analysis of periodontal and peri-implant flora with metagenomic, culturomic or 16S gene analysis was included. No language restrictions were applied. Risk of bias for RCT was assessed using the Cochrane collaboration's tool whereas case-control and cohort studies were evaluated through the Newcastle-Ottawa scale. Results: The initial search resulted in 330 titles in total. After careful evaluation of all results no studies were found to satisfy the primary outcome of the present review. Hence a narrative review dealing with the secondary aim was performed. Conclusions: Metagenomic and 16S gene analysis approaches contributed in clarifying some crucial aspects of the oral microbiome. Based on the reported evidence some bacteria could be found around teeth and implants even in the absence of signs of inflammation and other species are more frequently found in supragingival peri-implant biofilm. Teeth and implants (even if adjacent) seem not to share the same microbiome and healthy teeth have a more diversified one. The same analyses also highlighted that the oral biofilm of smokers is composed by more periodontopathogen bacteria compared to non-smokers and that geographical location and ethnicity seem to play a role in bacterial composition. Culturomics, which has not yet been applied to the study of oral microbiota, consists of the use of different culture conditions and of the identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) with the aim of increasing the bacterial repertoire and avoiding the limits of molecular methods. In order to better evaluate perspectives and limits of the all presented approaches further studies comparing the different molecular techniques are encouraged. This review received no funding.
