RESUMO
Aeromonas are ubiquitous in aquatic habitats. However some species can cause infections in humans, but rarely meningitis. Here we describe the isolation and characterization of an Aeromonas strain from cerebrospinal fluid of a meningitis patient. The isolate, identified as A. trota by biochemical and molecular methods, was susceptible to ampicillin but resistant to cephalothin and cefazolin. Genome sequencing revealed virulence factor genes such as type VI secretion system, aerolysin and lateral flagella. The isolate exhibited swarming motility, hemolytic activity and adhesion and cytotoxicity on HeLa cells. This is the first report of A. trota associated with meningitis and its virulence characteristics.
Assuntos
Aeromonas/classificação , Aeromonas/isolamento & purificação , Líquido Cefalorraquidiano/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Meningites Bacterianas/microbiologia , Aeromonas/genética , Aeromonas/fisiologia , Antibacterianos/farmacologia , Técnicas de Tipagem Bacteriana , Farmacorresistência Bacteriana , Genoma Bacteriano , Humanos , Testes de Sensibilidade Microbiana , Análise de Sequência de DNA , Fatores de Virulência/genéticaRESUMO
INTRODUCTION: A wide diversity of bacterial agents may cause diarrhea, presenting challenges to clinical laboratories to define a diagnosis. Considering that most stool cultures are negative, we screened stool samples from patients with diarrhea for the presence of 14 bacterial enteropathogens, aiming to establish which of them should be included in routine stool analysis. METHODOLOGY: Stool samples from 400 patients with diarrhea were analyzed for the presence of Salmonella, Shigella, Campylobacter, Aeromonas, Plesiomonas shigelloides, Vibrio, Yersinia enterocolitica, and diarrheagenic Escherichia coli using conventional microbiological methods and PCR. Two distinct samples were studied; one included predominantly patients involved in outbreaks, and the other patients of low socioeconomic status presenting sporadic cases of diarrhea. RESULTS: In total, 86 cultures (21.5%) were positive. Mixed infections were found in five patients, leading to recovery of 91 strains of enteropathogenic bacteria: Salmonella Enteritidis (9.2%), Aeromonas (7.2%), diarrheagenic E. coli (5.2%), and C. jejuni (1%). However, Salmonella predominated, with 11.5% frequency in diarrhea outbreaks, while Aeromonas predominated among patients of low socioeconomic status, with 14.6% frequency. CONCLUSION: Aeromonas and diarrheagenic E. coli, which are not routinely screened for, deserve to be included in laboratory screening panels.
