Movatterモバイル変換

[0]ホーム
URL:

Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
Thehttps:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

NIH NLM Logo
Log inShow account info
Access keysNCBI HomepageMyNCBI HomepageMain ContentMain Navigation
pubmed logo
Advanced Clipboard
User Guide

Full text links

Atypon full text link Atypon Free PMC article
Full text links

Actions

Share

.2017 Jun 16;83(13):e00593-17.
doi: 10.1128/AEM.00593-17. Print 2017 Jul 1.

Yersinia pestis Resists Predation by Acanthamoeba castellanii and Exhibits Prolonged Intracellular Survival

Affiliations

Yersinia pestis Resists Predation by Acanthamoeba castellanii and Exhibits Prolonged Intracellular Survival

Javier A Benavides-Montaño et al. Appl Environ Microbiol..

Abstract

Plague is a flea-borne rodent-associated zoonotic disease caused byYersinia pestis The disease is characterized by epizootics with high rodent mortalities, punctuated by interepizootic periods when the bacterium persists in an unknown reservoir. This study investigates the interaction betweenY. pestis and the ubiquitous soil free-living amoeba (FLA)Acanthamoeba castellanii to assess if the bacterium can survive within soil amoebae and whether intracellular mechanisms are conserved between infection of mammalian macrophages and soil amoebae. The results demonstrate that during coculture with amoebae, representativeY. pestis strains of epidemic biovars Medievalis, Orientalis, and Antiqua are phagocytized and able to survive within amoebae for at least 5 days. KeyY. pestis determinants of the intracellular interaction ofY. pestis and phagocytic macrophages, PhoP and the type three secretion system (T3SS), were then tested for their roles in theY. pestis-amoeba interaction. Consistent with a requirement for the PhoP transcriptional activator in the intracellular survival ofY. pestis in macrophages, a PhoP mutant is unable to survive when cocultured with amoebae. Additionally, induction of the T3SS blocks phagocytic uptake ofY. pestis by amoebae, similar to that which occurs during macrophage infection. Electron microscopy revealed that inA. castellanii,Y. pestis resides intact within spacious vacuoles which were characterized using lysosomal trackers as being separated from the lysosomal compartment. This evidence for prolonged survival and subversion of intracellular digestion ofY. pestis within FLA suggests that protozoa may serve as a protective soil reservoir forY. pestisIMPORTANCEYersinia pestis is a reemerging flea-borne zoonotic disease. Sylvatic plague cycles are characterized by an epizootic period during which the disease spreads rapidly, causing high rodent mortality, and an interepizootic period when the bacterium quiescently persists in an unknown reservoir. An understanding of the ecology ofY. pestis in the context of its persistence in the environment and its reactivation to initiate a new epizootic cycle is key to implementing novel surveillance strategies to more effectively predict and prevent new disease outbreaks. Here, we demonstrate prolonged survival and subversion of intracellular digestion ofY. pestis within a soil free-living amoeba. This suggests the potential role for protozoa as a protective soil reservoir forY. pestis, which may help explain the recrudescence of plague epizootics.

Keywords: Yersinia pestis; free-living amoeba; interepizootic plague.

Copyright © 2017 American Society for Microbiology.

PubMed Disclaimer

Figures

FIG 1
FIG 1
Invasion frequency of Y. pestis strains cocultured with A. castellanii ATCC 30010. White bars indicate an MOI of 1 and gray bars an MOI of 100. Error bars represent mean ± standard deviation (SD) of the results from 3 to 6 independent experiments. Statistically significant differences are indicated by ** forP < 0.01 and by *** forP < 0.001, and ns means not statistically significant.
FIG 2
FIG 2
Prolonged intra-amoebal survival of Y. pestis strains. Intracellular survival of Y. pestis in cocultures maintained in gentamicin at 25°C (A) and 4°C (B). Error bars represent the mean ± SD of the results from 3 to 6 independent experiments. Horizontal bars indicate comparisons between two time points. Statistically significant differences are indicated by ** forP < 0.01 and by *** forP < 0.001, and ns means not statistically significant.
FIG 3
FIG 3
Prolonged intra-amoebal survival of Y. pestis KIM strains in the absence of gentamicin. Intracellular survival of Y. pestis excluding gentamicin maintenance of cocultures at 25°C. Error bars represent the mean ± SD of the results from 3 to 6 independent experiments. For assays with KIM5 (blue), KIM6+ (orange), and the KIM5 T3SS mutant (yellow), horizontal bar indicates comparison between two time points at an MOI of 100, while vertical bar indicates comparisons between MOI of 1 (triangles) and 100 (circles). ns means not statistically significant.
FIG 4
FIG 4
Transmission electron micrographs of A. castellanii ATCC 30010 infected with Y. pestis KIM5. (A) An uninfected amoeba trophozoite. (B and C) Amoeba trophozoite infected with Y. pestis localized within spacious vacuoles at 24 h (B) and 7 days (C) post-coculture using MOI of 100. White arrows point to intracellular Y. pestis. V, vacuole; M, mitochondria; N, nucleus; P, pseudopodia.
FIG 5
FIG 5
A. castellanii ATCC 30010 phagocytosis of Y. pestis KIM5 and KIM5 T3SS mutant grown under T3SS-inducing conditions. (A) Invasion frequency and early survival (3 h postinfection) of Y. pestis KIM5 and KIM5 T3SS mutant cocultured with A. castellanii ATCC 30010 under T3SS-inducing conditions. (B) Early intracellular survival of KIM5 (blue) and KIM5 T3SS mutant (yellow). ●, intracellular CFU of bacteria per milliliter ; ▲, CFU of bacteria per milliliter before wash; ◆, CFU of bacteria per milliliter after wash. Error bars represent means ± SD of the results from at least 3 independent experiments. Statistically significant differences are indicated by *** forP < 0.001.
FIG 6
FIG 6
Intra-amoebal localization of GFP-expressing Y. pestis KIM5 and KIM5 T3SS mutant strains grown under T3SS-inducing conditions. Percent extracellular (Extra; nonpermeabilized infected amoebae, gray bars) or intracellular (Intra; permeabilized infected amoebae, white bars) Y. pestis. (A) Localization of bacteria was determined in 50 permeabilized and nonpermeabilized amoebae associated with GFP-expressing Y. pestis in each of two independent experiments per strain. Values are the means, and error bars represent the SD. Statistically significant differences are indicated by * forP < 0.0001. (B) Infected amoebae visualized using phase-contrast light microscopy and fluorescence microscopy showing colocalization or not of GFP-expressing bacteria and Alexa Fluor 594 red fluorescence (αrF1 antibody binding) to indicate extracellular (nonpermeabilized) or intracellular (permeabilized) localization of bacteria in association with amoebae. White arrows indicate Y. pestis cells.
FIG 7
FIG 7
Phagosome trafficking of Y. pestis KIM5 using gold nanoparticles to track lysosomes. (A) Percent colocalization of Y. pestis or 1.1-μm latex beads with 10 nm of BSA conjugated with colloidal gold nanoparticles (BSA-CGN) in A. castellanii ATCC 30010 vacuoles was determined from 50 infected phagosomes at 2 h and 24 h postinfection for each of 2 independent experiments. All data are given as means ± SD. Statistically significant differences are indicated by **** forP < 0.0001. (B and C) Colocalization of BSA-CGN with latex beads at 3 h (B) and 24 h (C). (D and E) Lack of colocalization of BSA-CGN with Y. pestis KIM5 at 3 h (D) and 24 h (E). Black asterisks indicate latex beads in panels B and C and Y. pestis in panels D and E. Arrows indicate lysosomal compartments loaded with BSA-CGN.
FIG 8
FIG 8
Hypothetical interepizootic plague cycle depicting the putative role of amoebae during these periods. A black question mark is used to indicate hypothetical infection routes. Refer to the Discussion for details.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Bertherat E, Bekhoucha S, Chougrani S, Razik F, Duchemin JB, Houti L, Deharib L, Fayolle C, Makrerougrass B, Dali-Yahia R, Bellal R, Belhabri L, Chaieb A, Tikhomirov E, Carniel E. 2007. Plague reappearance in Algeria after 50 years, 2003. Emerg Infect Dis 13:1459–1462. doi:10.3201/eid1310.070284. - DOI - PMC - PubMed
    1. Cabanel N, Leclercq A, Chenal-Francisque V, Annajar B, Rajerison M, Bekkhoucha S, Bertherat E, Carniel E. 2013. Plague outbreak in Libya, 2009, unrelated to plague in Algeria. Emerg Infect Dis 19:230–236. doi:10.3201/eid1902.121031. - DOI - PMC - PubMed
    1. Andrianaivoarimanana V, Kreppel K, Elissa N, Duplantier JM, Carniel E, Rajerison M, Jambou R. 2013. Understanding the persistence of plague foci in Madagascar. PLoS Negl Trop Dis 7:e2382. doi:10.1371/journal.pntd.0002382. - DOI - PMC - PubMed
    1. Navid A, Almaas E. 2009. Genome-scale reconstruction of the metabolic network in Yersinia pestis, strain 91001. Mol Biosyst 5:368–375. doi:10.1039/b818710j. - DOI - PubMed
    1. Chain PSG, Carniel E, Larimer FW, Lamerdin J, Stoutland PO, Regala WM, Georgescu AM, Vergez LM, Land ML, Motin VL, Brubaker RR, Fowler J, Hinnebusch J, Marceau M, Medigue C, Simonet M, Chenal-Francisque V, Souza B, Dacheux D, Elliott JM, Derbise A, Hauser LJ, Garcia E. 2004. Insights into the evolution of Yersinia pestis through whole-genome comparison with Yersinia pseudotuberculosis. Proc Natl Acad Sci U S A 101:13826–13831. doi:10.1073/pnas.0404012101. - DOI - PMC - PubMed

MeSH terms

Substances

Related information

LinkOut - more resources

Full text links
Atypon full text link Atypon Free PMC article
Cite
Send To

NCBI Literature Resources

MeSHPMCBookshelfDisclaimer

The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Unauthorized use of these marks is strictly prohibited.

[8]ページ先頭
©2009-2025 Movatter.jp