Cellular adherence, invasion and locomotion

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Please see attached document for the answers. Thanks and all the best!

Problem:
1.) Compare and contrast the mechanisms of pathogenicity developed by foodborne enteropathagenic E. coli, Salmonella and Shigella species that cause infections in the human host. Include : adherence, invasion, intracelluler locomotion.

SOLUTION:
Preliminaries:
Cellular adherence, invasion and locomotion are the three very important aspects by which the bacteria rely on for strategies on how to exploit, survive and persist within the host cell. Only this time that certain bacteria will be able to inflict the desired disease to the affected host (Goosney et al., 1999).

Now, we have to realize the fact that the cytoskeleton of the bacteria is an essential component that provides the bacteria the mechanism for cell shape, structure and even apoptosis or programmed cell death. Thus, anything that can alter the integrity of its cytoskeleton is a potential threat to the bacterial ability to adhere, invade and move intracellularly and survive (Goosney, Knoechel, & B. B. Finlay, 1999).

When I was doing research about your posting, something interesting popped out because incidentally what I got was the so-called representative bacteria of various aspects in your questions. It is because, when we talk about adherence, the best example (representative) for that is the Enteropathogenic Escherichia coli (EPEC) (the so-called expert on bacterial attachment and effacement; for invasion, we have the Salmonella typhimurium; and for intracellular motility, we have the Shigella flexneri (Goosney et al., 1999). Just as we would expect, these species of bacteria have been well known to cause various severe diseases to susceptible hosts.
The following information will explain how they do it.

Enteropathogenic Escherichia coli (EPEC):
While much has been known about diseases mechanisms for other strain like those of enterotoxigenic E. coli or enteroinvasive E. coli, knowledge about how EPEC causes disease still lags behind (Goosney et al., 1999). Indeed, knowing how these organisms cause disease is paramount as pathogenic E. coli strains are well known to cause severe and persistent diarrhea especially in infants.

EPEC is now recognized as one of those primary pathogens that cause the what we called attaching and effacing (A/E) lesions on intestinal cells (Moon, Whipp, Argenzio, Levine, & Giannella, 1983). Once present on the on a pedestal on the surface of the host epithelial cell, A/E pathogen like the EPEC causes severe disruption of the microvilli brush border (Moon et al., 1983).

The mechanism of ...