Actin accumulation associated with clustered and localized adherence in Escherichia coli isolated from patients with diarrhea

Abstract

Escherfihia coli D2 (serotype 07:H-) that was isolated from a child with diarrhea hybridized with an F1845 DNA probe used to detect diffuse adherence. Strain D2 adhered to tissue culture cells (HeLa and HEp-2 cells) in a clustered pattern but did not autoagglutinate on the cell surface and induced the elongation of microvilli after 3 h of incubation. After 6 h of incubation, the infected cells were positive for fluorescent-actin staining at the site of clustered adherence. When analyzed with a confocal laser scanning microscope, each D2 cell was surrounded by accumulated actin in a capsule-like formation. Capsule-like, accumulated actin was also observed with enteropathogenic E. coli (EPEC), although in this case, actin accumulation was associated with EPEC microcolonies in a localized pattern. Four other strains of F1845 DNA probe-positive, diffusely adhering E. coli were negative for actin accumulation. Strain D2 did not hybridize with EPEC attaching and effacing DNA or EPEC adherence factor DNA probes. In addition, clustered D2 cells were found inside tissue culture cells. The data suggest a novel infectious mechanism as well as genetic heterogeneity of F1845 DNA probe-positive E. coli. Capsule-like, accumulated actin may protect the bacteria from host defense mechanisms.

Interleukin‐8 Secretion by Epithelial Cells Infected with Diffusely Adherent Escherichia coli Possessing Afa Adhesin‐Coding Genes

“…Goluszko et al indicated that the Afa which interacted with DAF could promote bacterial internalization (19). These DAEC strains can induce fingerlike projections extending from the surface of infected tissue culture cells, which embed the bacteria and protect them from gentamicin (2,8,57). It is also likely that bacterial internalization and IL-8 induction depends on the subtype of Afa, since the different adhesins may bind to different sites on DAF molecules and thus cause functional differences (40).…”

Pathogenesis of Human Diffusely Adhering Escherichia coli Expressing Afa/Dr Adhesins (Afa/Dr DAEC): Current Insights and Future Challenges

“…This is a particular drawback for the detection of human AfaE-VIII adhesin-positive ExPEC strains (43)(44)(45). Moreover, the DCA could give overestimated results since several aEPEC strains have been found to be daaC positive (13,(46)(47)(48)(49)(50)(51)(52)(53).…”

“…The observation of daaC positivity of some aEPEC strains is indicative that Afa/Dr adhesins are expressed by enterovirulent E. coli strains other than Afa/Dr DAEC (13,(46)(47)(48)(49)(50)(51)(52)(53). Moreover, E. coli isolates displaying daaC and afaBC positivities have been found among AIEC, inflammatory bowel disease (IBD)-associated, and intestinal cancer-associated (6,(138)(139)(140) strains.…”

“…Cell membrane extensions attached or entrapping adhering Afa/Dr DAEC have been observed in infected epithelial cells. Yamamoto et al (51) observed that cell membrane extensions are connected to the daaC-positive strain D2 adhering to Hep-2 and HeLa cells. Cookson and Nataro (424) observed cell membrane extensions in close contact with adhering bacteria in C1845-infected Hep-2 cells.…”

Jamming bacterial communication: New approaches for the treatment of infectious diseases

“…Silica nanoparticles provide a means for rapid diffusion of toxic NO for better biofilm dispersion Hetrick et al (2008Hetrick et al ( , 2009 metal, gallium (Ga), has also been shown to prevent the formation of biofilms that are characteristic of chronic infections (Yamamoto et al, 1994). Ga works by competing out iron (Fe) that is necessary for bacterial metabolism and also serves as a cue for biofilm formation (Banin et al, 2005(Banin et al, , 2006.…”