RESUMO
Brain abscess remains a life-threatening condition. Here, we are reporting a case of brain abscess due to Bacteroides thetaiotaomicron in a previously known case of recurrent otitis media. A 15 years old boy with a history of recurrent otitis media presented with the complaints of right otalgia, headache and fever. Computed Tomography (CT) brain and neck revealed fluid filled right middle ear cavity with bony destruction along the inner cortex of right temporal bone. The abscess was drained and culture showed growth of Bacteroides thetaiotaomicron. This report illustrates the importance of MALDI-TOF MS in the species level identification of anaerobes thereby facilitating the selection of appropriate and prompt adjuvant antibiotic therapy. This timely identification thus led to a favourable outcome in an era of increasing antimicrobial resistance.
Assuntos
Bacteroides thetaiotaomicron , Abscesso Encefálico , Otite Média , Adolescente , Antibacterianos/uso terapêutico , Infecções por Bacteroides/tratamento farmacológico , Bacteroides thetaiotaomicron/classificação , Bacteroides thetaiotaomicron/isolamento & purificação , Bacteroides thetaiotaomicron/patogenicidade , Abscesso Encefálico/tratamento farmacológico , Abscesso Encefálico/microbiologia , Humanos , Masculino , Otite Média/tratamento farmacológico , Otite Média/microbiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodosRESUMO
Consumption of glucosinolates, pro-drug-like metabolites abundant in Brassica vegetables, has been associated with decreased risk of certain cancers. Gut microbiota have the ability to metabolize glucosinolates, generating chemopreventive isothiocyanates. Here, we identify a genetic and biochemical basis for activation of glucosinolates to isothiocyanates by Bacteroides thetaiotaomicron, a prominent gut commensal species. Using a genome-wide transposon insertion screen, we identified an operon required for glucosinolate metabolism in B. thetaiotaomicron. Expression of BT2159-BT2156 in a non-metabolizing relative, Bacteroides fragilis, resulted in gain of glucosinolate metabolism. We show that isothiocyanate formation requires the action of BT2158 and either BT2156 or BT2157 in vitro. Monocolonization of mice with mutant BtΔ2157 showed reduced isothiocyanate production in the gastrointestinal tract. These data provide insight into the mechanisms by which a common gut bacterium processes an important dietary nutrient.