Temperature-Dependent Parasitic Relationship between
 Legionella pneumophila
 and a Free-Living Amoeba (
 Acanthamoeba castellanii
 )

Ohno, Akira; Kato, Naoyuki; Sakamoto, Ryota; Kimura, Soichiro; Yamaguchi, Keizo

doi:10.1128/aem.00083-08

Cited by 56 publications

(57 citation statements)

References 21 publications

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“…Moreover, at a 100 MOI, significant Lp CFU increases were observed as early as day 1 at 30°C incubation, compared to day 2 levels at 25°C ( Figure 4C, P < 0.001) confirming the observations from previous studies that Legionella infectivity of FLA is temperature dependent [29,32].…”

Section: Resultssupporting

confidence: 80%

“…Previous studies have reported the temperature-dependent bacterial infectivity of FLA. Depending on the bacteria species, at low temperatures (<20-30°C), bacteria were actively digested, displayed low amplification rates, and/or eliminated from the FLA, A. polyphaga or A. castellanii; however, at higher temperatures (25-37°C), the amoeba was parasitized by the same strain of bacteria [29][30][31]. Thus, in this study, the higher MOI and temperature were used for the evaluation of the putative infectivity of virulent Schu4 and NY98 strains for the FLA cells.…”

Section: Resultsmentioning

confidence: 99%

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Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae

Buse

Schaefer

Rice

2016

Acta Microbiologica et Immunologica Hungarica

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Transmission of Francisella tularensis, the etiologic agent of tularemia, has been associated with various water sources. Survival of many waterborne pathogens within free-living amoeba (FLA) is well documented; however, the role of amoebae in the environmental persistence of F. tularensis is unclear. In this study, axenic FLA cultures of Acanthamoeba castellanii, Acanthamoeba polyphaga, and Vermamoeba vermiformis were each inoculated with virulent strains of F. tularensis (Types A and B), the attenuated live vaccine strain, and Francisella novicida. Experimental parameters included low and high multiplicity of infection and incubation temperatures of 25 and 30°C for 0-10 days. Francisella spp. survival was enhanced by the presence of FLA; however, bacterial growth and protozoa infectivity were not observed. In contrast, coinfections of A. polyphaga and Legionella pneumophila, used as an amoeba pathogen control, resulted in bacterial proliferation, cytopathic effects, and amoebal lysis. Collectively, even though short-term incubation with FLA was beneficial, the long-term effects on Francisella survival are unknown, especially given the expenditure of available amoebal derived nutrients and the fastidious nature of Francisella spp. These factors have clear implications for the role of FLA in Francisella environmental persistence.

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Section: Resultssupporting

confidence: 80%

Section: Resultsmentioning

confidence: 99%

Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae

Buse

Schaefer

Rice

2016

Acta Microbiologica et Immunologica Hungarica

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“…For the generation of L. pneumophila UNC, PE cells were washed two times in sterilized tap water and subsequently inoculated in sterilized tap water to an OD660 of 0.3, corresponding to ϳ2 ϫ 10 8 CFU/ml. The water microcosms were statically incubated at 42°C to induce VBNC bacteria as described elsewhere (41). To study the effect of temperature for efficient generation of VBNC L. pneumophila, samples were incubated at 4°C, 21°C, 42°C, and only the latter condition lead to loss of culturability and maintenance of viability in a reasonable time (ϳ110 days).…”

Section: Methodsmentioning

confidence: 99%

Life Stage-specific Proteomes of Legionella pneumophila Reveal a Highly Differential Abundance of Virulence-associated Dot/Icm effectors

Auraß

Gerlach

Becher

et al. 2016

Molecular & Cellular Proteomics

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Major differences in the transcriptional program underlying the phenotypic switch between exponential and post-exponential growth of Legionella pneumophila were formerly described characterizing important alterations in infection capacity. Additionally, a third state is known where the bacteria transform in a viable but nonculturable state under stress, such as starvation. We here describe phase-related proteomic changes in exponential phase (E), postexponential phase (PE) bacteria, and unculturable microcosms (UNC) containing viable but nonculturable state cells, and identify phasespecific proteins. We present data on different bacterial subproteomes of E and PE, such as soluble whole cell proteins, outer membrane-associated proteins, and extracellular proteins. In total, 1368 different proteins were identified, 922 were quantified and 397 showed differential abundance in E/PE. The quantified subproteomes of soluble whole cell proteins, outer membrane-associated proteins, and extracellular proteins; 841, 55, and 77 proteins, respectively, were visualized in Voronoi treemaps. 95 proteins were quantified exclusively in E, such as cell division proteins MreC, FtsN, FtsA, and ZipA; 33 exclusively in PE, such as motility-related proteins of flagellum biogenesis FlgE, FlgK, and FliA; and 9 exclusively in unculturable microcosms soluble whole cell proteins, such as hypothetical, as well as transport/binding-, and metabolism-related proteins. A high frequency of differentially abundant or phase-exclusive proteins was observed among the 91 quantified effectors of the major virulence-associated protein secretion system Dot/Icm (> 60%). 24 were E-exclusive, such as LepA/B, YlfA, MavG, Lpg2271, and 13 were PE-exclusive, such as RalF, VipD, Lem10. The growth phase-related specific abundance of a subset of Dot/Icm virulence effectors was confirmed by means of Western blotting. We therefore conclude that many effectors are predominantly abundant at either E or PE which suggests their phase specific function. The distinct temporal or spatial presence of such proteins might have important implications for functional assignments in the future or for use as lifestage specific markers for pathogen analysis. Molecular

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“…The uptake and growth of Legionella within acanthamoeba is temperature sensitive. 9 Acanthamoeba castellani would encyst at 15°C, up to 20°C digests L. pneumophila, at 25°C-35°C the bacteria replicate freely 10 and at 37°C and above lyses the protozoa. 11 A stable relationship exists between Odyssella thessalonicensis and amoebae at 20°C but at 30°C-37°C it lyses the amoeba.…”

Section: Ulceransmentioning

confidence: 99%

In the case of transmission of Mycobacterium ulcerans in Buruli ulcer disease Acanthamoeba species stand accused

Wilson

Boakye²,

Mosi³

et al. 2011

Ghana Medical Journal

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SUMMARYBuruli ulcer disease caused by Mycobacterium ulcerans results in extensive destruction of skin and soft tissue and long-term functional disabilities that ultimately require surgery and rehabilitation. The disease is associated with aquatic and swampy environments with the mycobacterium occurring in biofilms, soil, aquatic insects, fish and wildlife however, the mode of transmission to humans remains an enigma. Current transmission ideas including bites from predatory water bugs and mosquitoes, do not explain satisfactorily the spasmodic disease distribution in human populations. Here we argue that Acanthamoeba species are the natural hosts of M. ulcerans and are mainly responsible for disease transmission because; (i) Acanthamoebae are known natural hosts of several microbial pathogens including M. marinum, M. avium and Legionella pneumophila, (ii) culture of slow-to-grow microbial pathogens hosted in nature by Acanthamoeba spp is enhanced when the media is seeded with the protozoa, (iii) acanthamoebae and M. ulcerans share similar bio-ecological and epidemiological settings, (iv) documented evidence that prior growth of L. pneumophila and M. avium in acanthamoebae influences entry mechanisms, intracellular growth and virulence in human monocytes, (v) Acanthamoeba spp also infect humans and cause diseases via routes of openings including broken skin and sites of trauma similar to M. ulcerans and (vi) M. ulcerans is rather a fastidious intracellular organism as recent analysis of the genome indicate. We argue further that temperature plays a significant role in transmission determining the fate of either the intracellular microbe or the host cells. Also, Acanthamoeba-pathogen association has a long evolutionary history because the same set of bacterial genes and gene products e.g. in L. pneumophila are required for survival in both mammalian and protozoan host cells. We suggest that the involvement of Acanthamoeba in the transmission of M. ulcerans to humans better explains the disease's epidemiology.

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Temperature-Dependent Parasitic Relationship between Legionella pneumophila and a Free-Living Amoeba ( Acanthamoeba castellanii )

Cited by 56 publications

References 21 publications

Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae

Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae

Life Stage-specific Proteomes of Legionella pneumophila Reveal a Highly Differential Abundance of Virulence-associated Dot/Icm effectors

In the case of transmission of <i>Mycobacterium ulcerans</i> in Buruli ulcer disease <i>Acanthamoeba </i>species stand accused

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