Received September 30, 2009; Revised October 05, 2009; Accepted October 05, 2009.
Abstract
After morphological grouping of Acanthamoeba by Pussard and Pons, phylogeny of the genus has been always a big topic to the researchers. Because of the variability of morphological characteristics, unchangeable and stable characters have been investigated for phylogenic criteria. Isoenzyme and mitochondrial DNA RFLP (Mt DNA RFLP) analyses revealed different patterns among strains assigned to a same species. Therefore, these characteristics would be considered as tools for strain discrimination than species identification. The most recently developed and the most promising method is the sequence analysis of 18s ribosomal RNA coding DNA (18s rDNA). The phylogenic tree based on comparison of 18s rDNA sequences distinguished the 3 morphological groups of Acanthamoeba and divided them into 12 unique sequence types (T1-T12 genotypes). Most clinical and environmental isolates belonged to the morphological group II and the genotype T4. In the Republic of Korea, 2 strains of Acanthamoeba, YM-2 and YM-3, were first isolated from the environment in 1974. However, phylogenic identification of Korean Acanthamoeba isolates from human infections or the environment were tried from the late 1990s. By RFLP analysis or total sequence analysis of 18s rDNA revealed that almost all clinical isolates including the one from a suspicious granulomatous amebic encephalitis patient belonged to the genotype T4. A large number of environmental isolates from contact lens storage cases, tapped water, and ocean sediments also belonged to the genotype T4. Almost identical strain characteristics, such as Mt DNA RFLP pattern of environmental isolates, with the clinical isolates could make a simple conclusion that most environmental isolates might be a potential keratopathogen.
Patel DV,McGhee CN. Acanthamoeba keratitis: a comprehensive photographic reference of common and uncommon signs. Clin Experiment Ophthalmol 2009;37:232–238.
3.
Ringsted J,Jager BV,Suk D,Visvesvara GS. Probable acanthamoeba meningoencephalitis in a Korean child. Am J Clin Pathol 1976;66:723–730.
4.
Im K,Kim DS. Acanthamoebiasis in Korea: two new cases with clinical cases review. Yonsei Med J 1998;39:478–484.
5.
Pussard M,Pons R. Morphologie de la paroi kystiqueet taxonomie du genre Acanthamoeba (Protozoa, Amoebida). Protistologica 1977;8:557–598.
6.
Sawyer T. Acanthamoeba griffini, a new species of marine amoeba. J Protozool 1971;18:650–654.
7.
Stratford MP,Griffiths AJ. Excystment of the amoeba Hartmannella castellanii. J Gen Microbiol 1971;66:247–249.
8.
Visvesvara GS. Classification of Acanthamoeba. Rev Infect Dis 1991;13 suppl 5:S369–S372.
9.
Costas M,Griffiths AJ. The suitability of starch gel electrophoresis of esterases and acid phosphatases for the study of Acanthamoeba taxonomy. Arch Protistenk 1980;123:272–279.
10.
Costas M,Griffithes AJ. The characterization of 71 strains of Acanthamoeba using starch electrophoresis of isozymes. (Abstr); 4th Int Cong Protozool; Warsaw, Poland. Jul. Progress in Protozoology 63
11.
Costas M,Griffiths AJ. Enzyme composition and the taxonomy of Acanthamoeba. J Protozool 1985;32:604–607.
12.
Mathews HM,Moss DM,Healy GR,Visvesvara GS. Polyacrylamide gel electrophoresis of isoenzymes from Entamoeba species. J Clin Microbiol 1983;17:1009–1012.
13.
De Jonckheere JF. Isoenzyme and total protein analysis by agarose isoelectric focusing, and taxonomy of the genus Acanthamoeba. J Protozool 1983;30:701–706.
14.
Kong HH,Park JH,Chung DI. Interstrain polymorphisms of isoenzyme profiles and mitochondrial DNA fingerprints among seven strains assigned to Acanthamoeba polyphaga. Korean J Parasitol 1995;33:331–340.
15.
Bogler SA,Zarley CD,Burianek LL,Fuerst PA,Byers TJ. Interstrain mitochondrial DNA polymorphism detected in Acanthamoeba by restriction endonuclease analysis. Mol Biochem Parasitol 1983;8:145–163.
16.
Yagita K,Endo T. Restriction enzyme analysis of mitochondrial DNA of Acanthamoeba strains in Japan. J Protozool 1990;37:570–575.
17.
Gautom RK,Lory S,Seyedirashti S,Bergeron DL,Fritsche TR. Mitochondrial DNA fingerprinting of Acanthamoeba spp. isolated from clinical and environmental sources. J Clin Microbiol 1994;32:1070–1073.
18.
Byers TJ,Hugo ER,Stewart VJ. Genes of Acanthamoeba: DNA, RNA and protein sequences (a review). J Protozool 1990;37:17S–25S.
19.
Kilvington S,Beeching JR,White DG. Differentiation of Acanthamoeba strains from infected corneas and the environment by using restriction endonuclease digestion of whole-cell DNA. J Clin Microbiol 1991;29:310–314.
20.
Chung DI,Kong HH,Yu HS,Oh YM,Yee ST,Lim YJ. Biochemical and molecular characterization of a strain KA/S2 of Acanthamoeba castellanii isolated from Korean soil. Korean J Parasitol 1996;34:79–85.
21.
Chung DI,Yu HS,Hwang MY,Kim TH,Kim TO,Yun HC,Kong HH. Subgenus classification of Acanthamoeba by riboprinting. Korean J Parasitol 1998;36:69–80.
22.
Bhattacharya S,Som I,Bhattacharya A. The ribosomal DNA plasmids of Entamoeba. Parasitol Today 1998;14:181–185.
23.
Khan NA,Paget TA. Molecular tools for speciation and epidemiological studies of Acanthamoeba. Curr Microbiol 2002;44:444–449.
24.
Kong HH,Chung DI. PCR and RFLP variation of conserved region of small subunit ribosomal DNA among Acanthamoeba isolates assigned to either A. castellanii or A. polyphaga. Korean J Parasitol 1996;34:127–134.
25.
Gast RJ,Ledee DR,Fuerst PA,Byers TJ. Subgenus systematics of Acanthamoeba: four nuclear 18S rDNA sequence types. J Eukaryot Microbiol 1996;43:498–504.
26.
Stothard DR,Schroeder-Diedrich JM,Awwad MH,Gast RJ,Ledee DR,Rodriguez-Zaragoza S,Dean CL,Fuerst PA,Byers TJ. The evolutionary history of the genus Acanthamoeba and the identification of eight new 18S rRNA gene sequence types. J Eukaryot Microbiol 1998;45:45–54.
27.
Schroeder JM,Booton GC,Hay J,Niszl IA,Seal DV,Markus MB,Fuerst PA,Byers TJ. Use of subgenic 18S ribosomal DNA PCR and sequencing for genus and genotype identification of Acanthamoebae from humans with keratitis and from sewage sludge. J Clin Microbiol 2001;39:1903–1911.
28.
Yu HS,Kong HH,Kim SY,Hahn YH,Hahn TW,Chung DI. Laboratory investigation of Acanthamoeba lugdunensis from patients with keratitis. Invest Ophthalmol Vis Sci 2004;45:1418–1426.
29.
Lee SJ,Jeong HJ,Lee JE,Lee JS,Xuan YH,Kong HH,Chung DI,Ock MS,Yu HS. Molecular characterization of Acamthamoeba isolated from amebic keratitis related to orthokeratology lens overnight wear. Korean J Parasitol 2006;44:313–320.
30.
Yu HS,Hwang MY,Kim TO,Yun HC,Kim TH,Kong HH,Chung DI. Phylogenetic relationships among Acanthamoeba spp. based on PCR-RFLP analyses of mitochondrial small subunit rRNA gene. Korean J Parasitol 1999;37:181–188.
31.
Ledee DR,Booton GC,Awwad MH,Sharma S,Aggarwal RK,Niszl IA,Markus MB,Fuerst PA,Byers TJ. Advantages of using mitochondrial 16S rDNA sequences to classify clinical isolates of Acanthamoeba. Invest Ophthalmol Vis Sci 2003;44:1142–1149.
32.
Hwang HK,Im KI,Soh CT,Yun DJ. Experimental study on the pathogenicity of free-living amoebae. Yonsei J Med Sci 1976;9:182–194.
33.
Jones DB,Visvesvara GS,Robinson NM. Acanthamoeba polyphaga keratitis and Acenthamoeba uveitis associated with fatal meningoencephalitis. Trans Ophthalmol Soc (UK) 1975;95:221–232.
34.
Yu HS,Kong HH,Kim SY,Hahn YH,Hahn TW,Chung DI. Laboratory investigation of Acanthamoeba lugdunensis from patients with keratitis. Invest Ophthalmol Vis Sci 2004;45:1418–1426.
35.
Xuan YH,Chung BS,Hong YC,Kong HH,Hahn TW,Chung DI. Keratitis by Acanthamoeba triangularis: report of cases and characterization of isolates. Korean J Parasitol 2008;46:157–164.
36.
Lee SM,Choi YJ,Ryu HW,Kong HH,Chung DI. Species identification and molecular characterization of Acanthamoeba isolated from contact lens paraphernalia. Korean J Ophthalmol 1997;11:39–50.
37.
Yu HS,Choi KH,Kim HK,Kong HH,Chung DI. Genetic analyses of Acanthamoeba isolates from contact lens storage cases of students in Seoul, Korea. Korean J Parasitol 2001;39:161–170.
38.
Kong HH,Shin JY,Yu HS,Kim J,Hahn TW,Hahn YH,Chung DI. Mitochondrial DNA restriction fragment length polymorphism (RFLP) and 18S small-subunit ribosomal DNA PCR-RFLP analyses of Acanthamoeba isolated from contact lens storage cases of residents in southwestern Korea. J Clin Microbiol 2002;40:1199–1206.
39.
Jeong HJ,Lee SJ,Kim JH,Xuan YH,Lee KH,Park SK,Choi SH,Chung DI,Kong HH,Ock MS,Yu HS. Acanthamoeba: keratopathogenicity of isolates from domestic tap water in Korea. Exp Parasitol 2007;117:357–367.
40.
Liu H,Ha YR,Lee ST,Hong YC,Kong HH,Chung DI. Genetic diversity of Acanthamoeba isolated from ocean sediments. Korean J Parasitol 2006;44:117–125.
41.
Im KI,Shin HJ. Acanthamoeba sohi, n. sp., a pathogenic Korean isolate YM-4 from a freshwater fish. Korean J Parasitol 2003;41:181–188.
