Isolation and Molecular Characterization of Entamoeba nuttalli Strains Showing Novel Isoenzyme Patterns from Wild Toque Macaques in Sri Lanka.
We have proposed the revival of the name Entamoeba nuttalli for a virulent ameba strain, P19-061405, from a rhesus macaque and located it phylogenetically between E. histolytica and E. dispar. As E. nuttalli was originally described for an ameba found in a toque macaque in Sri Lanka, the prevalence and characteristics of Entamoeba species in wild toque macaques were examined. PCR analysis of 227 stool samples from six locations showed positive rates for E. nuttalli, E. dispar, and E. histolytica of 18.5%, 0.4%, and 0%, respectively. Fifteen E. nuttalli strains were cultured successfully from five locations. The 18S ribosomal RNA gene showed only three nucleotide differences in comparison with P19-061405 strain. In isoenzyme analysis, the pattern of hexokinase in Sri Lankan strains was different from that of P19-061405 strains and the difference was confirmed by analysis of the genes. Hepatic inoculation of one of the Sri Lankan E. nuttalli strains in hamsters resulted in amebic abscess formation and body weight loss. These results demonstrate that E. nuttalli is prevalent in wild toque macaques and that several characteristics of the strains are unique. We conclude that use of the name E. nuttalli is appropriate for the new Entamoeba species found in nonhuman primates.
Department of Infectious Diseases, Tokai University School of Medicine, Isehara, Kanagawa, 259-1193, Japan.
Hiroshi
H
Tachibana
Department of Immunogenetics, Institute of Tropical Medicine, Nagasaki University, Nagasaki, 852-8523, Japan.
Tetsuo
T
Yanagi
Department of Infectious Diseases, Tokai University School of Medicine, Isehara, Kanagawa, 259-1193, Japan.
Meng
M
Feng
Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya, Sri Lanka.
K B Anura T
KB
Bandara
Department of Tropical Medicine and Parasitology, Keio University School of Medicine, Tokyo, 160-8582, Japan.
Seiki
S
Kobayashi
Department of Infectious Diseases, Tokai University School of Medicine, Isehara, Kanagawa, 259-1193, Japan.
Xunjia
X
Cheng
Department of Immunogenetics, Institute of Tropical Medicine, Nagasaki University, Nagasaki, 852-8523, Japan.
Kenji
K
Hirayama
Department of Veterinary Pathobiology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, Peradeniya, Sri Lanka.
R P V Jayanthe
RP
Rajapakse
D000818:Animals; D006224:Cricetinae; D016054:DNA, Protozoan / Q000235:genetics; D004747:Entamoeba / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D004749:Entamoebiasis / Q000469:parasitology / Q000662:veterinary*; D005838:Genotype; D006593:Hexokinase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007527:Isoenzymes; D008251:Macaca / Q000469:parasitology*; D008297:Male; D008647:Mesocricetus; D008992:Monkey Diseases / Q000469:parasitology*; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic; D015995:Prevalence; D013188:Sri Lanka
D016054:DNA, Protozoan; D007527:Isoenzymes; D006593:Hexokinase
Cultivation; diversity; epidemiology; rDNA; virulence