Bacterial diversity and prevalence of antibiotic resistance genes in the oral microbiome

Abstract

This study aims to describe the oral microbiome diversity and prevalence of ARGs in periodontal health and disease. Background The human oral cavity harbors a complex microbial community known as the oral microbiome. These organisms are regularly exposed to selective pressures, such as the usage of antibiotics, which drive evolution and acquisition of antibiotic resistance genes (ARGs). Resistance among oral bacteria jeopardizes not only antibiotic therapy for oral infections, but also extra-oral infections caused by bacterial translocation. Methods We carried out a cross-sectional investigation. Saliva and subgingival plaque samples were collected during a clinical exam. 16S rRNA gene sequencing was performed to assess microbial diversity. Resistance genes were identified through PCR assays. Results Of the 110 participants, only 22.7% had healthy periodontium, while the majority was diagnosed with gingivitis (55.4%) and chronic periodontitis (21.8%). The composition of the oral microbiota differed from healthy and diseased samples, being Streptococcus spp. and Rothia spp. predominant in periodontal disease. Regarding ARGs, 80 (72.7%) samples were positive for at least one of genes screened, erm being the most frequent variant (58.2%), followed by bla TEM (16.4%), mecA (2.7%), pbp2b and aac(6 ') (1.8%). Neither genes coding resistance to carbapenems nor metronidazole were detected. Conclusions Our findings indicate that there are no significant differences in terms of taxonomic enrichment between healthy and diseased oral microbiomes. However, samples retrieved from healthy patients had a more diverse microbial community, whereas diseased samples have

The oralome and its dysbiosis: New insights into oral microbiome-host interactions

“…For instance, Almeida et al . [148] reported significantly lower taxonomic diversity in subgingival microbial samples from both gingivitis and chronic periodontitis patients compared to healthy individuals (total of 110 participants). However, Griffen et al [150] reported a significantly higher taxonomic diversity for chronic periodontitis individuals compared to healthy controls (58 participants in total).…”

“…In terms of periodontal disease, changes in microbial diversity remain controversial, with some reports indicating loss of microbial diversity with periodontitis [146] , [147] , [148] , [149] , and others indicating the opposite (i.e., that periodontitis is associated with increased levels of microbial diversity compared to healthy control levels; as a consequence of the increased amount of nutrients derived from host’s tissue degradation [135] , [139] , [140] , [149] , [150] , [151] ; and even others reporting no significant difference between the groups (i.e., periodontitis vs. healthy patients) [152] , [153] . For instance, Almeida et al .…”

Prophylactic application of antibiotics selects extended‐spectrum β‐lactamase and carbapenemases producing Gram‐negative bacteria in the oral cavity

“…Previous studies analysed microbiome in the oral cavity of the patients suffering from periodontal diseases, but resistance genes except of bla TEM , bla CfxA and erm genes were not found (Almeida et al 2020;Arredondo et al 2020). The dominant species harbouring resistance determinants in sub gingival samples were Streptococcus spp and Prevotella spp, bacteria belonging to normal microbiota of the oral cavity.…”

Antibiotic Therapy in Dentistry

“…Antibiotics are suggested in the cases of prophylaxis for local and focal infections, besides, for the treatment of odontogenic and nonodontogenic infections [ 13 , 15 ]. Antibiotics are not indicated for all odontogenic infections; they should not be used instead of removal of the source of infections [ 16 ].…”