Acanthamoeba spp. as vehicle and reservoir of adenoviruses
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Adenoviruses are important pathogens which are responsible for human enteritic, respiratory and eye infections. These viruses have been found to be prevalent in several natural and artificial water reservoirs worldwide. Free-living amoebae (FLA) have been recovered from similar water reservoirs, and it has been shown that FLA may act as reservoirs or vehicles of various microorganisms living in the same environment. To examine the ability of FLA to harbour adenoviruses, an in vitro study was conducted. Several Acanthamoeba strains were ‘co-cultivated’ with adenoviruses (adenoviruses 11 and 41), grown on A549 cells, using a proven test protocol. After phagocytosis and ingestion, the adenoviruses could be found within the cytoplasm of the Acanthamoeba trophozoites. The intake of the viruses into the cytoplasm of the trophozoites was demonstrated in an Acanthamoeba castellanii strain with the help of fluorescence microscopy and electron microscopy. An adenovirus DFA kit, which utilizes a direct immunofluorescent antibody technique for identifying adenovirus in infected tissue cultures, was used. In our study, it was demonstrated that adenoviruses were incorporated into the host amoebae (Acanthamoeba sp. Grp. II, three strains). So far, there were only a few publications concerning the relationship of free-living amoebae and viruses; only one of these described the detection of adenoviruses within acanthamoebae with molecular biological methods. We conducted this descriptive study to further examine the association between viable adenoviruses and FLA. To our knowledge, this is the first study to demonstrate directly the adenoviruses within FLA as vectors and vehicles. Therefore, we concluded that free-living amoebae appear able to act as carriers or vectors of the adenoviruses and thus may play a certain role in the dispersal of adenoviruses.
KeywordsA549 Cell Food Vacuole Acanthamoeba Keratitis Acanthamoeba Castellanii Human Lung Adenocarcinoma Cell Line
We thank P. Hommer, M. Ferse and M. Weber for their help and assistance during this study. We also thank Dr. B. Hauröder and Mrs Schneider for their help in obtaining the impressive electron microscopic records.
- Barker J, Lambert PA, Brown MRW (1992) Influence of intra-amoebic and other growth conditions on the surface properties of Legionella pneumophila. Infect Immun 61:3503–3510Google Scholar
- Benkö M, Harrach B, Russell WC (2000) Adenoviridae. Family Adenoviridae. In: van Regenmortel MHV, Fauquet CM, Bishop DHL, Carstens EB, Estes MK, Lemon SM, Maniloff J, Mayo MA, McGeoch DJ, Pringle CR, Wickner RB (eds) Virus taxonomy: The Seventh Report of the International Committee on Taxonomy of Viruses. Academic, San Diego, pp 227–238Google Scholar
- Everett KDE, Bush RM, Anderssen AA (1999) Embedded description of the order Chlamydiales, proposal of Parachlamydiaceae fam. nov. and Simkaniaceae fam. nov., each containing one monotypic genus, revised taxonomy of the family Chlamydiaceae, including a new genus and five species, and standards for the identification of organisms. Int J Syst Bacteriol 49:415–440PubMedCrossRefGoogle Scholar
- Hierholzer JC (1995) Adenoviruses. In: Lennette EHLD, Lennette ET (eds) Diagnostic procedures for viral, rickettsial, andchlamydial infections, 7th edn. American Public Health Association, Washington, pp 169–188Google Scholar
- Karnovsky MJ (1965) A formaldehyde–glutaraldehyde fixative of high osmolality in electron microscopy. J Cell Biol 27:137AGoogle Scholar
- Michel R (1997) Freilebende Amöben als Wirte und Vehikel von Mikroorganismen. Mitt Österr Ges Tropenmed Parasitol 19:11–20Google Scholar
- Michel R (2006) Isolation of free-living amoebae from various sources harbouring pro- and eukaryotic endocytobionts. Endocytobiosis Cell Res 17:127–136Google Scholar
- Selinka H, Botzenhart K, Feuerpfeil I, Puchert W, Schmoll O, Szewzyk R, Willmitzer H (2011) Nachweis von viren im rohwasser als grundlage einer risikoabschätzung. B Ges Blatt 54:496–504Google Scholar
- Walochnik J, Aspöck H (2005) Die diagnostik von infektionen mit freilebenden amöben (FLA). Lab Med 29(6):446–456Google Scholar