Legionella dumoffii Tex-KL Mutated in an Operon Homologous to traC-traD is Defective in Epithelial Cell Invasion.
Biomed Environ Sci
; 29(6): 424-34, 2016 Jun.
Article
de En
| MEDLINE
| ID: mdl-27470103
ABSTRACT
OBJECTIVE:
To understand the mechanism of invasion by Legionella dumoffii.METHODS:
The L. dumoffii strain Tex-KL was mutated using the Tn903 derivative, Tn903dIIlacZ. After screening 799 transposon insertion mutants, we isolated one defective mutant. We then constructed the gene-disrupted mutant, KL16, and studied its invasion of and intracellular growth in HeLa and A549 cells, and in A/J mice survival experiments. The structure of traC-traD operon was analyzed by RT-PCR.RESULTS:
The transposon insertion was in a gene homologous to Salmonella typhi traC, which is required for the assembly of F pilin into the mature F pilus structure and for conjugal DNA transmission. Results from RT-PCR suggested that the traC-traD region formed an operon. We found that when the traC gene was disrupted, invasion and intracellular growth of L. dumoffii Tex-KL were impaired in human epithelial cells. When mice were infected by intranasal inoculation with a traC deficient mutant, their survival significantly increased when compared to mice infected with the wild-type strain..CONCLUSION:
Our results indicated that the traC-traD operon is required for the invasion and intracellular growth abilities of L. dumoffii Tex-KL in epithelial cells.Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Opéron
/
Legionella
/
Gènes bactériens
Limites:
Animals
/
Humans
/
Male
Langue:
En
Journal:
Biomed Environ Sci
Sujet du journal:
SAUDE AMBIENTAL
Année:
2016
Type de document:
Article