The type III secretion system is involved in Escherichia coli K1 interactions with Acanthamoeba

Bacteria in the environment must survive predation from bacteriophage, heterotrophic protists, and predatory bacteria. This selective pressure has resulted in the evolution of a variety of defense mechanisms, which can also function as virulence factors. Here we discuss the potential dual function of some of the mechanisms, which protect against heterotrophic protists, and how predation pressure leads to the evolution of pathogenicity. This is in accordance with the coincidental evolution hypothesis, which suggests that virulence factors arose as a response to other selective pressures, for example, predation rather than for virulence per se. In this review we discuss some of those environmental factors that may be associated with the rise of pathogens in the marine environment. In particular, we will discuss the role of heterotrophic protists in the evolution of virulence factors in marine bacteria. Finally, we will discuss the implications for expansion of current pathogens and emergence of new pathogens.

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“…coli inside trophozoites of A . castellanii [85] and as a QS-independent anti-predator mechanism in P . aeruginosa [86].…”

Section: Type III Secretion Systemmentioning

confidence: 99%

The Rise of Pathogens: Predation as a Factor Driving the Evolution of Human Pathogens in the Environment

2013

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“…However, the importance of a somatic antigen as other virulence factor in E. coli is not clearly understood. E. coli K5 is a streptomycin-resistant strain of the serotype O7:K1 [18]. E. coli K1 and E. coli K5 possess different somatic antigens but an identical capsular antigen.…”

Section: Introductionmentioning

confidence: 99%

Interaction ofEscherichia coliK1 and K5 withAcanthamoeba castellaniiTrophozoites and Cysts

Matin

Jung

2011

Korean J Parasitol

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The existence of symbiotic relationships between Acanthamoeba and a variety of bacteria is well-documented. However, the ability of Acanthamoeba interacting with host bacterial pathogens has gained particular attention. Here, to understand the interactions of Escherichia coli K1 and E. coli K5 strains with Acanthamoeba castellanii trophozoites and cysts, association assay, invasion assay, survival assay, and the measurement of bacterial numbers from cysts were performed, and nonpathogenic E. coli K12 was also applied. The association ratio of E. coli K1 with A. castellanii was 4.3 cfu per amoeba for 1 hr but E. coli K5 with A. castellanii was 1 cfu per amoeba for 1 hr. By invasion and survival assays, E. coli K5 was recovered less than E. coli K1 but still alive inside A. castellanii. E. coli K1 and K5 survived and multiplied intracellularly in A. castellanii. The survival assay was performed under a favourable condition for 22 hr and 43 hr with the encystment of A. castellanii. Under the favourable condition for the transformation of trophozoites into cysts, E. coli K5 multiplied significantly. Moreover, the pathogenic potential of E. coli K1 from A. castellanii cysts exhibited no changes as compared with E. coli K1 from A. castellanii trophozoites. E. coli K5 was multiplied in A. castellanii trophozoites and survived in A. castellanii cysts. Therefore, this study suggests that E. coli K5 can use A. castellanii as a reservoir host or a vector for the bacterial transmission.

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“…The T3SS was found to be required for E. coli and P. aeruginosa for interaction with amoebae (Siddiqui et al, 2011;Abd et al, 2008). In particular, P. aeruginosa cytotoxin ExoU secreted by this system was reported to be necessary for intracellular survival within amoebae (Pukatzki et al, 2002).…”

Section: Jejuni Interaction With Tissue Culture Host Cellsmentioning

confidence: 99%

“…Different protein secretion systems were shown to be important for survival of other bacterial pathogens within amoeba. Examples are the T3SS and type IV secretion system, the former being important for both E. coli and P. aeruginosa survival within amoebae, and the latter for intracellular multiplication of L. pneumophila inside this protozoa (Siddiqui et al, 2011;Abd et al, 2008;Bandyopadhyay et al, 2004).…”

Section: Jejuni Interaction With Tissue Culture Host Cellsmentioning

confidence: 99%

Campylobacter–Acanthamoeba interactions

2015

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The type III secretion system is involved in Escherichia coli K1 interactions with Acanthamoeba

Cited by 19 publications

References 28 publications

The Rise of Pathogens: Predation as a Factor Driving the Evolution of Human Pathogens in the Environment

The Rise of Pathogens: Predation as a Factor Driving the Evolution of Human Pathogens in the Environment

Interaction ofEscherichia coliK1 and K5 withAcanthamoeba castellaniiTrophozoites and Cysts

Campylobacter–Acanthamoeba interactions

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