Apoptosis-like cell death induced by Salmonella in Acanthamoeba rhysodes

Feng, Ye; Hsiao, Yi-Hsing; Chen, Hsiu-Ling; Chu, Chishih; Tang, Petrus; Chiu, Cheng-Hsun

doi:10.1016/j.ygeno.2009.05.004

Cited by 34 publications

(33 citation statements)

References 34 publications

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“…Therefore, intracellular bacteria may represent only a transient state during initial coculture. The association of Salmonella serovar Typhi with Acanthamoeba was also different than that of S. serovar Typhimurium, which resulted in death of amoebae, corresponding more to a parasitic relationship (15,17,40). Even if these two Salmonella serovars share many virulence determinants, phenotypic differences have been demonstrated (16,36).…”

Section: Discussionmentioning

confidence: 99%

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Increased Persistence of Salmonella enterica Serovar Typhi in the Presence of Acanthamoeba castellanii

Douesnard-Malo

2011

Appl Environ Microbiol

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Salmonella enterica serovar Typhi (S. Typhi) is the etiological agent of the systemic disease typhoid fever. Transmission occurs via ingestion of contaminated food or water. S. Typhi is specific to humans, and no animal or environmental reservoirs are known. As the free-living amoeba Acanthamoeba castellanii is an environmental host for many pathogenic bacteria, this study investigates interactions between S. Typhi and A. castellanii by using cocultures. Growth of both organisms was estimated by cell count, viable count, flow cytometry, and fluorescence microscopy. Results indicate that S. Typhi can survive at least 3 weeks when grown with A. castellanii, as opposed to less than 10 days when grown as singly cultured bacteria under the same conditions. Interestingly, growth rates of amoebae after 14 days were similar in cocultures or when amoebae were singly cultured, suggesting that S. Typhi is not cytotoxic to A. castellanii. Bacteria surviving in coculture were not intracellular and did not require a physical contact with amoebae for their survival. These results suggest that S. Typhi may have a selective advantage when it is associated with A. castellanii and that amoebae may contribute to S. Typhi persistence in the environment.

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Section: Discussionmentioning

confidence: 99%

“…Salmonella enterica serovar Typhimurium was shown to replicate and survive in Acanthamoeba spp. ; however, it was cytotoxic and killed the protist (15,17,40).…”

mentioning

confidence: 99%

Increased Persistence of Salmonella enterica Serovar Typhi in the Presence of Acanthamoeba castellanii

Douesnard-Malo

2011

Appl Environ Microbiol

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“…S. enterica does not have any detectable cytotoxic effect in Tetrahymena (Brandl et al, 2005;Gourabathini et al, 2008), in contrast to Acanthamoeba spp., which are killed by S. enterica and other pathogenic species (Abu Kwaik et al, 1998;Gaze et al, 2003;Tezcan-Merdol et al, 2004;Matz et al, 2008;Feng et al, 2009). Hence, the role of SPI-2 and other virulence determinants in its resistance to digestion by Tetrahymena is less clear than their potential pathogenic function during interaction with Acanthamoeba rhysodes, in which SPI genes are also Figure 5 Frequency distribution of the number of S. Typhimurium cells in individual fecal pellets released by Tetrahymena during co-culture of the two microorganisms, as assessed with the Live/Dead BacLight stain.…”

Section: Discussionmentioning

confidence: 99%

“…induced (Feng et al, 2009). The possibility remains that increased expression of virulence genes in S. Typhimurium in Tetrahymena is simply a response to environmental signals present also in host phagocytic cells, particularly low pH (Yu et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

“…In addition, S. Typhimurium does not decrease the viability of Tetrahymena during its intravacuolar passage (Gourabathini et al, 2008). Therefore, its interaction appears to be different than with Acanthamoeba spp., which causes death of the protist (Gaze et al, 2003;Tezcan-Merdol et al, 2004;Feng et al, 2009). S. Typhimurium is an intracellular pathogen that has evolved specific mechanisms for its persistence and replication in eukaryotic cells.…”

Section: Introductionmentioning

confidence: 99%

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Salmonella transcriptional signature in Tetrahymena phagosomes and role of acid tolerance in passage through the protist

2010

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Salmonella enterica Typhimurium remains undigested in the food vacuoles of the common protist, Tetrahymena. Contrary to its interaction with Acanthamoeba spp., S. Typhimurium is not cytotoxic to Tetrahymena and is egested as viable cells in its fecal pellets. Through microarray gene expression profiling we investigated the factors in S. Typhimurium that are involved in its resistance to digestion by Tetrahymena. The transcriptome of S. Typhimurium in Tetrahymena phagosomes showed that 989 and 1282 genes were altered in expression compared with that in water and in LB culture medium, respectively. A great proportion of the upregulated genes have a role in anaerobic metabolism and the use of alternate electron acceptors. Many genes required for survival and replication within macrophages and human epithelial cells also had increased expression in Tetrahymena, including mgtC, one of the most highly induced genes in all three cells types. A DmgtC mutant of S. Typhimurium did not show decreased viability in Tetrahymena, but paradoxically, was egested at a higher cell density than the wild type. The expression of adiA and adiY, which are involved in arginine-dependent acid resistance, also was increased in the protozoan phagosome. A DadiAY mutant had lower viability after passage through Tetrahymena, and a higher proportion of S. Typhimurium wild-type cells within pellets remained viable after exposure to pH 3.4 as compared with uningested cells. Our results provide evidence that acid resistance has a role in the resistance of Salmonella to digestion by Tetrahymena and that passage through the protist confers physiological advantages relevant to its contamination cycle.

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Effect of Acanthamoeba Spp. Cell‐Free Supernatants on Some Bacterial Pathogens

Özcan Aykol,

Zeybek,

Kayabaş

et al. 2024

Journal of Basic Microbiology

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The fact that free‐living amoebae of the genus Acanthamoeba can live in many different environments causes these protozoa to have different interactions with other microorganisms. Investigation of Acanthamoeba–pathogenic bacteria interaction is important for the discovery of new antibacterial agents that can be used against pathogenic bacteria. In this study, it was aimed to investigate the antibacterial effect of cell‐free supernatants obtained from Acanthamoeba against some pathogenic bacteria. One standard strain (Acanthamoeba castellanii ATCC 50373) and one environmental strain (B1) of the genus Acanthamoeba were used in the study. Cell‐free supernatants were obtained by centrifuging the axenic cultures (3000 rpm, 5 min) and passing through a sterile filter with a pore diameter of 0.22 µm. The antibacterial effect of cell‐free supernatants against five different pathogenic bacteria (Acinetobacter baumannii, Klebsiella pneumoniae, Enterococcus faecalis, Salmonella Typhi, and Salmonella enterica) was investigated by colony counting method. As a result of the study, it was determined that the standard Acanthamoeba cell‐free supernatant showed the highest antibacterial effect against E. faecalis (75.79%), while B1 cell‐free supernatant showed the highest antibacterial effect against K. pneumoniae (8.5%). The content of the tested Acanthamoeba cell‐free supernatants was analyzed by gas chromatography/mass spectrometry in our previous study and was also found to contain major compounds with antibacterial properties. Therefore, it is thought that the metabolites produced by Acanthamoeba can be used as an alternative to existing antimicrobial drugs in the fight against infections caused by some important pathogenic bacteria.

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Apoptosis-like cell death induced by Salmonella in Acanthamoeba rhysodes

Cited by 34 publications

References 34 publications

Increased Persistence of Salmonella enterica Serovar Typhi in the Presence of Acanthamoeba castellanii

Increased Persistence of Salmonella enterica Serovar Typhi in the Presence of Acanthamoeba castellanii

Salmonella transcriptional signature in Tetrahymena phagosomes and role of acid tolerance in passage through the protist

Effect of Acanthamoeba Spp. Cell‐Free Supernatants on Some Bacterial Pathogens

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