• Parasites, Hosts and Diseases
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• v.34 no.4
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• pp.259-266
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• 1996

The taxonomic validity of morphological group III Accnthamoeba app. is uncertain. In the present study. six type strains of group III Aconthamoeba spry. , A. culbertsoni, A. heniyi, A. pustulosc, A. palestinensis, A. royrebn and A. lenticulnto were subjected for the evaluation or their taxonomic validity by comparison of the isoeneyme patterns by isoelectic focusing on polyacrylamide gels, mitochondrial DNA (Mt DNA) restriction fragment length polymorphism (RFLP) . and small subunit ribosomal DNA (ssu rDNA) PCR-RFLP patterns. The Mt DNA RFLP patterns were heterogeneous between the species. The type strains of A. pclestinensls and A. pustulosc showed almost identical patterns of isoenrymes and rDNA PCR-RFLP with an estimated sequence divergence of 2.6%. The other species showed heterogeneous patterns of isoenxymes and rDNA PCR- RFLP. It is likely that A. pustuLosc is closely related with A. palestinensis and that the former may be regarded as a junior synonym of the latter.

• Parasites, Hosts and Diseases
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• v.37 no.3
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• pp.181-188
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• 1999

We investigated the value of mitochondrial small subunit rRNA gene (mt SSU rDNA) PCR-RFLP as a taxonomic tool for Acanthamoeba isolates with close inter-relationships. Twenty-five isolates representing 20 species were included in the analysis. As in nuclear 18s rDNA analysis, two type strains (A. astronyxis and A. tubiashi) of morphological group 1 diverged earliest from the other strains, but the divergence between them was less than in 18s riboprinting. Acanthamoeba griffini of morhological group 2 branched between pathogenic (A. culbertsoni A-1 and A. healyi OC-3A) and nonpathogenic (A.palestinensis Reich, A. pustulosa GE-3a, A. royreba Oak Ridge, and A lenticulata PD2S) strains of morphological group 3. Among the remaining isolates of morphological group 2, the Chang strain had the identical mitochondrial riboprints as the type strain of A. hatchetti. AA2 and AA1, the type strains of A. divionensis and A. paradivionensis, respectively, had the identical riboprints as A. quina Vil3 and A. castellanii Ma. Although the branching orders of A. castellanii Neff, A. polyphaga P23, A. triangularis SH621, and A. lugdunensis L3a were different from those in 18S riboprinting analysis, the results obtained from this study generally coincided well with those from 18S riboprinting. Mitochondrial riboprinting may have an advantage over nuclear 18S rDNA riboprinting beacuse the mt SSU rDNAs do not seem to have introns that are found in the 18S genes of Acanthamoeba and that distort phylogenetic analyses.

• Parasites, Hosts and Diseases
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• v.34 no.2
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• pp.127-134
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• 1996

Twelve isolates of Accnthamoebc app. assigned to either A. castellanii or A. poIMphoSa, and type strains of A. culbefsoni, A. henIWi, A. pqkestinefiE, and A. astronyxi,s were examined by restriction fragment length polymorphism (RFLP) of a conserved region of small subunit ribosomal RMh gene (ssu rDNA) amplified by polymerase chain reaction (PCR). The PCR products of the isolates measured approximately 910-930 bp, except for that of A. astronyxis which was extraordinarily long, approximately 1,170 bp. Average of estimated sequence divergence of the amplified DNA among the isolates assigned to A. castellanii was 9.8% whereas that among the isolates assigned to A. polvphusn 9.6%. The maximum intraspecific sequence divergence among the isolates assigned to A. costellanii was observed between the Chang and Ma strains (17.3%) while that among the isolates assigned to A. poIWphosa was observed between KA/S3 and KA/S7 strains (16.1%). The both maximum sequence divergences were much greater than the minimum interspecific sequence divergence between A. cnstellnnii and A. polwphasa (2.6%) which appeared between the Castellani (or CCAP 1501/12 g) and KA/S3 strains. The PCR-RFLP patterns of A. culbertsoni, A. healyi, A. palestinensis, and A. ostronvxis were quite diverse from one another and from those of isolates assigned to either A. castellanii or A. polyphoga. It is suggested that taxonomic validity of the isolates assigned to either A. castellnnii or A. polyphoga should be reevaluated.