Isolation and characterization of a potentially virulent speciesEntamoeba nuttallifrom captive Japanese macaques

Abstract

We have recently proposed revival of the name Entamoeba nuttalli Castellani, 1908 for a virulent amoeba (P19-061405 strain) isolated from a rhesus monkey (Macaca mulatta) and located phylogenetically between E. histolytica and E. dispar. In this study, E. nuttalli was isolated from feces of captive Japanese macaques (M. fuscata) in an open-air corral in Japan. The sequence of the 18S rRNA gene in the isolates differed from the P19-061405 strain in 2 nucleotide positions, but was identical to the EHMfas1 strain isolated previously from a cynomolgus monkey (M. fascicularis). One of the E. nuttalli isolates from Japanese macaques, named the NASA6 strain, was axenized and cloned. In isoenzyme analysis, the mobilities of hexokinase and phosphate glucose isomerase in the NASA6 strain were identical to those in the P19-061405 and EHMfas1 strains, but the mobility of phosphoglucomutase was different. These results were supported by gene analyses of these enzymes. Inoculation of NASA6 strain trophozoites into the liver of hamsters led to formation of an amoebic liver abscess. The liver lesions were characterized by extensive necrosis associated with inflammatory reactions. These results demonstrate that the NASA6 strain is potentially virulent and that E. nuttalli should be recognized as a common parasite in macaques.

High prevalence of Entamoeba infections in captive long-tailed macaques in China

“…Serological detection of E. histolytica was reported in 27% of the macaques. Recent studies also demonstrated high prevalence of E. nuttalli infections in macaques and other nonhuman primates (Levecke et al 2010;Suzuki et al 2007;Tachibana et al 2007Tachibana et al , 2009Takano et al 2007). …”

Molecular Testing for Clinical Diagnosis and Epidemiological Investigations of Intestinal Parasitic Infections

“…As a result, DNA amplification will occur but will probably not be detected by this assay. Whereas E. nuttalli appears to be virulent in nonhuman primates, at present, it remains unclear whether E. nuttalli can infect and cause disease in humans (53)(54)(55)(56)(57).…”

Peroxiredoxins in Parasites

“…8a). With 8 and 20 possible loci in the two species, we suspect that more of these will represent unique Prx genes, especially since seven were cloned from a single strain of Entamoeba nuttalli, a rhesus monkey parasite (243,244).…”