RESUMO
Environmental factors, such as cigarette smoking or lung infections, may influence chronic obstructive pulmonary disease (COPD) progression by modifying the respiratory tract microbiome. However, whether the disease itself induces or maintains dysbiosis remains undefined. In this longitudinal study, we investigated the oropharyngeal microbiota composition and disease progression of mice (in cages of 5-10 mice per cage) before, during and up to 3 months after chronic cigarette smoke exposure or exposure to room air for 6 months. Cigarette smoke exposure induced pulmonary emphysema measurable at the end of exposure for 6 months, as well as 3 months following smoke exposure cessation. Using both classical culture methods and 16S rRNA sequencing, we observed that cigarette smoke exposure altered the relative composition of the oropharyngeal microbiota and reduced its diversity (P <0.001). More than 60 taxa were substantially reduced after 6 months of smoke exposure (P <0.001) However, oropharyngeal microbiota disordering was reversed 3 months after smoke exposure cessation and no significant difference was observed compared to age-matched control mice. The effects of lung infection with Streptococcus pneumoniae on established smoke-induced emphysema and on the oropharyngeal microbiota were also evaluated. Inoculation with S. pneumoniae induced lung damage and altered the microbiota composition for a longer time compared to control groups infected but not previously exposed to smoke (P=0.01). Our data demonstrate effects of cigarette smoke and pneumococcus infection leading to altered microbiota and emphysema development. The reversal of the disordering of the microbiota composition, but not lung damage, following smoke exposure cessation and after clearance of infection suggest that changes in lung structure are not sufficient to sustain a disordered microbiota in mice. Whether changes in the airway microbiota contribute to inducing emphysema requires further investigation.
Assuntos
Bactérias/classificação , Disbiose/etiologia , Orofaringe/microbiologia , Infecções Pneumocócicas/microbiologia , Enfisema Pulmonar/genética , RNA Ribossômico 16S/genética , Fumaça/efeitos adversos , Animais , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , DNA Ribossômico/genética , Modelos Animais de Doenças , Progressão da Doença , Disbiose/induzido quimicamente , Disbiose/complicações , Disbiose/microbiologia , Feminino , Estudos Longitudinais , Camundongos , Filogenia , Enfisema Pulmonar/induzido quimicamente , Enfisema Pulmonar/microbiologia , RNA Bacteriano/genética , Análise de Sequência de DNA/métodos , Produtos do Tabaco/efeitos adversosRESUMO
Monitoring the health of research animals is an essential part of the research process and helps to ensure that experiments yield reliable and reproducible results. The Federation of European Laboratory Animal Science Associations (FELASA) is one organization that accredits and evaluates health monitoring programs and laboratories involved with health monitoring. In this article, the authors (who are members of the FELASA working group Accreditation Board for Health Monitoring) describe the guidelines of the FELASA health monitoring accreditation process. The ultimate goal of this accreditation program is to make health monitoring reports more thorough and reliable, thereby increasing the standardization of health monitoring of laboratory animals.