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

No abstract

Keratosis lichenoides chronica or Nekam´s disease is a rare mucocutaneous dermatosis characterized by keratinization. It is chronic and progressive usually affecting individuals aged 20-40 years. Around 70 cases have been reported in the literature. Due to the rarity of this condition and the lack of effective treatment, it is a difficult disease to manage. In the case described below we present a 42-yearold patient with violaceous and hyperkeratotic papules in linear, reticular or plaque form, located on the trunk and limbs for five years. Aphthous lesions in the oral cavity and shallow ulcers on the genitalia also formed part of the clinical manifestation. Pathologic examination was suggestive of keratosis lichenoides chronica. Acitretin and dapsone was introduced and the lesions partially improved. Keywords: Keratosis; Lichenoid eruptions; Skin diseases Resumo: A queratose liquenoide crônica ou doença de Nekam é uma dermatose mucocutânea rara da queratinização, com curso crônico e progressivo, que acomete geralmente indivíduos entre 20 e 40 anos. Existem, aproximadamente, 70 casos descritos na literatura. Devido à raridade desta dermatose e à ausência de tratamento efetivo, é uma doença de difícil manejo. No caso em questão, apresentamos um paciente de 42 anos com pápulas violáceas, hiperqueratósicas, algumas confluentes, com aspecto linear, rendilhado e em placas, localizadas no tronco e membros há cinco anos. Lesões aftoides na cavidade oral e úlceras rasas na genitália também faziam parte do quadro. O anatomopatológico foi bastante sugestivo de queratose liquenoide crônica. Introduziu-se tratamento com acitretina e dapsona, havendo melhora parcial do quadro.

No abstract