RESUMO
Up until now, Bacteroides faecis, a Gram-negative, anaerobic, non-motile, nonsporeforming rod has been principally described as a commensal microbe isolated from the feces of healthy adults. We report the first case of human Bacteroides faecis sepsis after removal of suspected post-colonic ischemia colonized epicardic electrodes. Electrodes and blood cultures both grew Gram-negative anaerobic rods but usual phenotypic methods and 16S rARN gene sequencing failed to ensure its species identification. B. faecis was finally identified using hsp60 gene sequencing. Because this species is not well-known and is difficult to identify, it may have been overlooked or misidentified in previous studies.
Assuntos
Proteínas de Bactérias/genética , Infecções por Bacteroides/microbiologia , Bacteroides/isolamento & purificação , Chaperonina 60/genética , Sepse/microbiologia , Idoso , Antibacterianos/uso terapêutico , Proteínas de Bactérias/química , Bacteroides/classificação , Bacteroides/efeitos dos fármacos , Bacteroides/genética , Infecções por Bacteroides/diagnóstico , Infecções por Bacteroides/tratamento farmacológico , Infecções por Bacteroides/patologia , Chaperonina 60/química , Evolução Fatal , Expressão Gênica , Humanos , Masculino , Testes de Sensibilidade Microbiana , Filogenia , Sepse/diagnóstico , Sepse/tratamento farmacológico , Sepse/patologia , Análise de Sequência de DNA , Falha de TratamentoRESUMO
The clinical course of a case of infant botulism was characterized by several relapses despite therapy with amoxicillin and metronidazole. Botulism was confirmed by identification of botulinum toxin and Clostridium botulinum in stools. A C. botulinum A2 strain resistant to penicillins and with heterogeneous resistance to metronidazole was isolated from stool samples up to 110 days after onset. Antibiotic susceptibility was tested by disc agar diffusion and MICs were determined by Etest. Whole genome sequencing allowed detection of a gene cluster composed of blaCBP for a novel penicillinase, blaI for a regulator, and blaR1 for a membrane-bound penicillin receptor in the chromosome of the C. botulinum isolate. The purified recombinant penicillinase was assayed. Resistance to ß-lactams was in agreement with the kinetic parameters of the enzyme. In addition, the ß-lactamase gene cluster was found in three C. botulinum genomes in databanks and in two of 62 genomes of our collection, all the strains belonging to group I C. botulinum. This is the first report of a C. botulinum isolate resistant to penicillins. This stresses the importance of antibiotic susceptibility testing for adequate therapy of botulism.
