Transposon mutagenesis and identification of mutated genes in growth-delayed Edwardsiella ictaluri.
BMC Microbiol
; 19(1): 55, 2019 03 08.
Article
em En
| MEDLINE
| ID: mdl-30849940
BACKGROUND: Edwardsiella ictaluri is a Gram-negative facultative intracellular anaerobe and the etiologic agent of enteric septicemia of channel catfish (ESC). To the catfish industry, ESC is a devastating disease due to production losses and treatment costs. Identification of virulence mechanisms of E. ictaluri is critical to developing novel therapeutic approaches for the disease. Here, we report construction of a transposon insertion library and identification of mutated genes in growth-delayed E. ictaluri colonies. We also provide safety and efficacy of transposon insertion mutants in catfish. RESULTS: An E. ictaluri transposon insertion library with 45,000 transposants and saturating 30.92% of the TA locations present in the E. ictaluri genome was constructed. Transposon end mapping of 250 growth-delayed E. ictaluri colonies and bioinformatic analysis of sequences revealed 56 unique E. ictaluri genes interrupted by the MAR2xT7 transposon, which are involved in metabolic and cellular processes and mostly localized in the cytoplasm or cytoplasmic membrane. Of the 56 genes, 30 were associated with bacterial virulence. Safety and vaccine efficacy testing of 19 mutants showed that mutants containing transposon insertions in hypothetical protein (Eis::004), and Fe-S cluster assembly protein (IscX, Eis::039), sulfurtransferase (TusA, Eis::158), and universal stress protein A (UspA, Eis::194) were safe and provided significant protection (p < 0.05) against wild-type E. ictaluri. CONCLUSIONS: The results indicate that random transposon mutagenesis causing growth-delayed phenotype results in identification bacterial virulence genes, and attenuated strains with transposon interrupted virulence genes could be used as vaccine to activate fish immune system.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vacinas Bacterianas
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Elementos de DNA Transponíveis
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Edwardsiella ictaluri
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Infecções por Enterobacteriaceae
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Doenças dos Peixes
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
BMC Microbiol
Assunto da revista:
MICROBIOLOGIA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
Reino Unido