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Review
. 2021 Feb 18;10(2):225.
doi: 10.3390/pathogens10020225.

A Systematic Review of Intracellular Microorganisms within Acanthamoeba to Understand Potential Impact for Infection

Binod Rayamajhee  1   2 , Dinesh Subedi  3 , Hari Kumar Peguda  1 , Mark Duncan Willcox  1 , Fiona L Henriquez  4 , Nicole Carnt  1
Affiliations
Review

A Systematic Review of Intracellular Microorganisms within Acanthamoeba to Understand Potential Impact for Infection

Binod Rayamajhee et al. Pathogens. .

Abstract

Acanthamoeba, an opportunistic pathogen is known to cause an infection of the cornea, central nervous system, and skin. Acanthamoeba feeds different microorganisms, including potentially pathogenic prokaryotes; some of microbes have developed ways of surviving intracellularly and this may mean that Acanthamoeba acts as incubator of important pathogens. A systematic review of the literature was performed in order to capture a comprehensive picture of the variety of microbial species identified within Acanthamoeba following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Forty-three studies met the inclusion criteria, 26 studies (60.5%) examined environmental samples, eight (18.6%) studies examined clinical specimens, and another nine (20.9%) studies analysed both types of samples. Polymerase chain reaction (PCR) followed by gene sequencing was the most common technique used to identify the intracellular microorganisms. Important pathogenic bacteria, such as E. coli, Mycobacterium spp. and P. aeruginosa, were observed in clinical isolates of Acanthamoeba, whereas Legionella, adenovirus, mimivirus, and unidentified bacteria (Candidatus) were often identified in environmental Acanthamoeba. Increasing resistance of Acanthamoeba associated intracellular pathogens to antimicrobials is an increased risk to public health. Molecular-based future studies are needed in order to assess the microbiome residing in Acanthamoeba, as a research on the hypotheses that intracellular microbes can affect the pathogenicity of Acanthamoeba infections.

Keywords: Acanthamoeba; carrier; co-infection; intracellular microbes; survival.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Representation of the different microorganisms as food of Acanthamoeba and interaction with bacteria. (a) attachment: possible receptor-mediated adhesion of bacteria; (b) entry: ingestion of bacteria using pseudopods and phagocytosis; (c) trafficking: prevention of phagosome-lysosome fusion by bacteria helps them evade lysosomal degradation and prevents acidification of the phagosomes [39]; (d) spread: vacuoles containing microbes disperse throughout the amoebal cytoplasm; and (e) replication: intraphagosomal replication of bacteria possible eventual escape into the amoebal cytoplasm.
Figure 2
Figure 2
Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) flow diagram for selection of articles.
Figure 3
Figure 3
Laboratory procedures for the isolation and identification of Acanthamoeba and associated intracellular microorganisms from clinical and environmental samples. Adapted from Thomas et al. (2010) [37]. PAS: Page’s Amoeba Saline, NNA: Non-nutrient agar, TEM = Transmission Electron Microscopy, SEM = Scanning Electron Microscope. Created with BioRender.com (accessed on 20 January 2021).
See this image and copyright information in PMC

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References

    1. Neelam S., Niederkorn J.Y. Pathobiology and immunobiology of Acanthamoeba keratitis: Insights from animal models. Yale J. Biol. 2017;90:261–268. - PMC - PubMed
    1. Goldschmidt P., Degorge S., Saint-Jean C., Year H., Zekhnini F., Batellier L., Laroche L., Chaumeil C. Resistance of Acanthamoeba to classic DNA extraction methods used for the diagnosis of corneal infections. Br. J. Ophthalmol. 2008;92:112–115. doi: 10.1136/bjo.2007.125898. - DOI - PubMed
    1. Torno M.S., Jr., Babapour R., Gurevitch A., Witt M.D. Cutaneous acanthamoebiasis in AIDS. J. Am. Acad. Dermatol. 2000;42:351–354. doi: 10.1016/S0190-9622(00)90110-5. - DOI - PubMed
    1. Dunand V.A., Hammer S.M., Rossi R., Poulin M., Mary A., Doweiko J.P., DeGirolami P.C., Coakley E., Piessens E., Wanke C.A. Parasitic sinusitis and otitis in patients infected with human immunodeficiency virus: Report of five cases and review. J Clin. Infect. Dis. 1997;25:267–272. doi: 10.1086/514536. - DOI - PubMed
    1. Rayamajhee B., Subedi D., Won S., Kim J.J.Y., Vijay A., Tan J., Henriquez F.L., Willcox M., Carnt N.A.J.W. Investigating Domestic Shower Settings as a Risk Factor for Acanthamoeba Keratitis. Water. 2020;12:3493. doi: 10.3390/w12123493. - DOI

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