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Scheid P.,Central Institute Of The Bundeswehr Medical Service Koblenz Andernacherstr 100 | Hauroder B.,Central Institute of the Bundeswehr Medical Service | Michel R.,Central Institute Of The Bundeswehr Medical Service Koblenz Andernacherstr 100
Parasitology Research | Year: 2010

In this article, the results of investigations concerning a parasitic endocytobiont within the host amoebae (Acanthamoeba sp.) are presented. The endocytobiont was recently isolated from the contact lens and the inflamed eye of a patient with keratitis. Light microscopy and electron microscopy were performed to provide morphological details: Light microscopy revealed the presence of ovoid microorganisms developing and proliferating within the cytoplasm of the amoebic trophozoites. Details of the unusual development of these endocytobionts within the amoebae could be studied and demonstrated by means of electron microscopy. Foldings and morphological reorganization of the microorganisms took place exclusively within the host cytoplasm. The intracellularly aggregating organisms led to the rupture of the Acanthamoeba trophozoites after proliferation. Numerous microorganisms were released, which were infectious and were subsequently ingested by hitherto uninfected acanthamoebic trophozoites. To evaluate the in vitro growth of the isolated endocytobionts (without their hosts), they were transferred to several different culture plates. There was no growth of these unique organisms on five different common cultural plates suitable for the growth of bacteria and fungi. © 2010 Springer-Verlag.


Scheid P.L.,Central Institute Of The Bundeswehr Medical Service Koblenz Andernacherstr 100 | Schwarzenberger R.,Central Institute Of The Bundeswehr Medical Service Koblenz Andernacherstr 100
Parasitology Research | Year: 2011

In the present article, the study to examine the ability of free-living amoebae (FLA) to serve as vectors of cryptosporidia is presented. Ten strains of different free-living amoebae of the FLA collection of the Parasitology Lab at Koblenz were cultivated in the presence of Cryptosporidium parvum oocysts. After phagocytosis and ingestion, the oocysts could be found in food vacuoles within the cytoplasm of the trophozoites of two different FLA strains. The uptake and the transport of the oocysts within the trophozoites could be demonstrated in an Acanthamoeba sp. (group II) strain (maximum, three oocysts; average, one oocyst) as well as in a Thecamoeba quadrilineata strain (maximum, 15 oocysts; average, eight oocysts), with the help of light microscopy. We found that these free-living amoebae can temporarily harbour cryptosporidia, thus supporting the suggestion that FLA may act as carriers and vehicles for cryptosporidia. However, proliferation did not take place within the host amoebae. No cryptosporidium oocysts were found within the cysts of the amoebae. To our knowledge, this is the first study to determine the "host range" of free-living amoebae as vectors and vehicles of cryptosporidia. Free-living amoebae appear able to act as carriers or vectors of the oocysts and thus may play a certain role in the transmission of cryptosporidia. © 2011 Springer-Verlag.


Scheid P.,Central Institute Of The Bundeswehr Medical Service Koblenz Andernacherstr 100 | Schwarzenberger R.,Central Institute Of The Bundeswehr Medical Service Koblenz Andernacherstr 100
Parasitology Research | Year: 2012

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. © 2012 Springer-Verlag.


PubMed | Central Institute Of The Bundeswehr Medical Service Koblenz Andernacherstr 100
Type: Journal Article | Journal: Parasitology research | Year: 2012

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.


PubMed | Central Institute of the Bundeswehr Medical Service Koblenz andernacherstr 100
Type: Journal Article | Journal: Parasitology research | Year: 2010

In this article, the results of investigations concerning a parasitic endocytobiont within the host amoebae (Acanthamoeba sp.) are presented. The endocytobiont was recently isolated from the contact lens and the inflamed eye of a patient with keratitis. Light microscopy and electron microscopy were performed to provide morphological details: Light microscopy revealed the presence of ovoid microorganisms developing and proliferating within the cytoplasm of the amoebic trophozoites. Details of the unusual development of these endocytobionts within the amoebae could be studied and demonstrated by means of electron microscopy. Foldings and morphological reorganization of the microorganisms took place exclusively within the host cytoplasm. The intracellularly aggregating organisms led to the rupture of the Acanthamoeba trophozoites after proliferation. Numerous microorganisms were released, which were infectious and were subsequently ingested by hitherto uninfected acanthamoebic trophozoites. To evaluate the in vitro growth of the isolated endocytobionts (without their hosts), they were transferred to several different culture plates. There was no growth of these unique organisms on five different common cultural plates suitable for the growth of bacteria and fungi.

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