The Escherichia coli Efflux Pump TolC Promotes Aggregation of Enteroaggregative E. coli 042
| Autor: | Jav Sarantuya, Junichiro Nishi, Mayumi Iwashita, Koichi Tokuda, Yoshifumi Kawano, Naoko Imuta, Rika Fujiyama, Kunihiro Manago |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Immunology
Colony Count Microbial Virulence medicine.disease_cause Microbiology Bacterial Adhesion Cell Line Intestinal mucosa Escherichia coli medicine Humans Sequence Deletion biology Escherichia coli Proteins Genetic Complementation Test Wild type Biofilm Membrane Transport Proteins biochemical phenomena metabolism and nutrition biology.organism_classification Molecular Pathogenesis Enterobacteriaceae Mutagenesis Insertional Infectious Diseases Biofilms Enteroaggregative Escherichia coli bacteria Mutant Proteins Parasitology Bacterial outer membrane Bacterial Outer Membrane Proteins |
| Zdroj: | Infection and Immunity. 76:1247-1256 |
| ISSN: | 1098-5522 0019-9567 |
| Popis: | Enteroaggregative Escherichia coli (EAEC) is an emerging enteric pathogen in both developing and industrialized countries. EAEC is defined as a diarrheal pathogen based on its characteristic aggregative adherence to HEp-2 cells in culture and its biofilm formation on the intestinal mucosa. We have reported that the novel protein AatA, which is encoded on the EAEC virulence plasmid pAA2, localizes to the outer membrane and facilitates export of the dispersin Aap across the outer membrane. Because AatA is an E. coli efflux pump TolC homolog, we investigated the role of TolC in the virulence of EAEC. No difference in Aap secretion was observed between the wild type and its tolC mutant (042 tolC ). However, characteristic aggregation in high-glucose Dulbecco's minimal essential medium for the wild type was diminished for 042 tolC . In a microtiter plate assay, there were significantly more planktonic cells for 042 tolC than for the wild type, while there were significantly fewer spontaneously precipitated cells on the substratum for 042 tolC than for the wild type. In a HEp-2 cell adherence test, 042 tolC showed less aggregative adherence than did the wild type. The strong aggregation and aggregative adherence were restored in the complement strain with tolC . In a transwell assay, planktonic cells of 042 tolC decreased when cocultured with the wild type or the complement, while precipitated cells of 042 tolC increased when cocultured with them. These results suggest that TolC promotes the aggregation and adhesion of EAEC 042 by secreting an assumed humoral factor. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|