Pathogenic and Opportunistic Free-Living Amebae

Govinda S. Visvesvara

doi:10.1128/9781555817381.ch139

Chapter 139 : Pathogenic and Opportunistic Free-Living Amebae

Author: Govinda S. Visvesvara

Content Type: Reference

Publication Year: 2015

Category: Clinical Microbiology

Book DOI: 10.1128/9781555817381

Chapter DOI: 10.1128/9781555817381.ch139

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Abstract:

Pathogenic and opportunistic free-living amebae, such as Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri, and Sappinia pedata, cause devastating central nervous system and disseminated infections in humans, leading to death. A brief review of the types of infections caused, clinical characteristics, pathologic manifestations, morphologic and molecular diagnoses, treatment, and prevention, if any, are discussed.

Citation: Visvesvara G. 2015. Pathogenic and Opportunistic Free-Living Amebae, p 2387-2398. In Jorgensen J, Pfaller M, Carroll K, Funke G, Landry M, Richter S, Warnock D (ed), Manual of Clinical Microbiology, Eleventh Edition. ASM Press, Washington, DC. doi: 10.1128/9781555817381.ch139

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Pathogenic and Opportunistic Free-Living Amebae

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FIGURES 1 through 4

N. fowleri. ( 1 ) Trophozoite, phase contrast (note the uroid and filaments at the arrow); ( 2 ) trophozoite, trichrome stain; ( 3 ) biflagellate, phase contrast; ( 4 ) smooth-walled cyst, phase contrast (note the pore at the arrow). All magnifications, approximately ×835. doi:10.1128/9781555817381.ch139.f1-4

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FIGURES 1 through 4

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FIGURES 5 and 6

A. castellanii. ( 5 ) Trophozoite, phase contrast (note the acanthopodia at the arrow); ( 6 ) double-walled cyst, phase contrast. Both magnifications, approximately ×835. doi:10.1128/9781555817381.ch139.f5-6

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FIGURES 5 and 6

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FIGURES 7 and 8

B. mandrillaris. ( 7 ) Trophozoite, phase contrast; ( 8 ) cyst, phase contrast. Both magnifications, approximately ×1,140. doi:10.1128/9781555817381.ch139.f7-8

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FIGURES 7 and 8

B. mandrillaris. ( 7 ) Trophozoite, phase contrast; ( 8 ) cyst, phase contrast. Both magnifications, approximately ×1,140. doi:10.1128/9781555817381.ch139.f7-8

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FIGURE 9

Large numbers of N. fowleri trophozoites (arrows) in a section of CNS tissue, showing extensive necrosis and destruction of brain tissue. Magnification, approximately ×564. doi:10.1128/9781555817381.ch139.f9

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FIGURE 9

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FIGURE 10

A. culbertsoni trophozoites (arrows) and a cyst (arrowhead) around a blood vessel in a section of CNS tissue from a GAE patient. Magnification, approximately ×489. doi:10.1128/9781555817381.ch139.f10

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FIGURE 10

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FIGURE 11

B. mandrillaris trophozoites and a cyst (arrowhead) in a brain section from a GAE patient. Note the double (small arrow) and triple (large arrow) nucleolar elements within the nuclei of the trophozoites. Magnification, approximately ×413. doi:10.1128/9781555817381.ch139.f11

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FIGURE 11

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FIGURE 12

Immunofluorescence localization of B. mandrillaris in a brain section from a GAE patient. Note the fluorescent amebae (arrows) around blood vessels. Magnification, approximately ×188. doi:10.1128/9781555817381.ch139.f12

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FIGURE 12

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