Entamoeba moshkovskiiInfections in Children in Bangladesh

Abstract

Entamoeba moshkovskii cysts are morphologically indistinguishable from those of the disease-causing species E. histolytica and the nonpathogenic E. dispar . Although sporadic cases of human infection with E. moshkovskii have been reported, the organism is considered primarily a free-living ameba. No simple molecular detection tool is available for diagnosing E. moshkovskii infections. We used polymerase chain reaction (PCR) to detect E. moshkovskii directly in stool. We tested 109 stool specimens from preschool children in Bangladesh by PCR; 17 were positive for E. histolytica (15.6%) and 39 were positive for E. dispar (35.8%). In addition, we found that 23 (21.1%) were positive for E. moshkovskii infection, and 17 (73.9%) of these also carried E. histolytica or E. dispar . The high association of E. moshkovskii with E. histolytica and E. dispar may have obscured its identification in previous studies. The high prevalence found in this study suggests that humans may be a true host for this ameba.

Comparison of multiplex-PCR and antigen detection for differential diagnosis of Entamoeba histolytica

“…Several studies that have investigated the prevalence of E. histolytica and E. dispar have not considered the presence of other species such as E. hartmanni and E. moshkovskii [19,22,23,36]. These species were reported in areas of Ghana, Pondicherry and Bangladesh [37][38][39]. These results suggest that species of Entamoeba that not belong to E. histolytica/E.…”

Development of Multiplex Real-Time Polymerase Chain Reaction for Detection of Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii in Clinical Specimens

“…differential diagnosis of the three species of Entamoeba that share identical morphology in clinical specimens, as both cysts and trophozoites. This technique requires only one PCR step, compared with at least two steps in the traditional nested PCR, 3 it is performed in a closed system where post -PCR handling is not required, and it is highly sensitive and could be used for quantitative purposes.…”

“…The coexistance of E. moshkovskii with E. dispar in stool sample has also been reported in Bangladesh using another PCR assay. 3 Because this is the first study ever conducted in Thailand to detect the presence of E. moshkovskii , it is not possible to estimate its prevalence. Therefore, more samples need to be studied before the prevalence of E. moshkovskii in the Thai population can be clearly determined.…”

“…1 This procedure is cheap and simple, but it has several limitations, such as being incapable of distinguishing between the cysts and trophozoites of the disease-causing species Entamoeba histolytica , the nonpathogenic Entamoeba dispar , and the free-living amoeba Entamoeba moshkovskii . A high prevalence and association of E. moshkovskii with E. histolytica and E. dispar has been reported in young children from Bangladesh 2,3 and E. moshkovskii was recently detected in patients between 31 and 50 years of age presenting with gastrointestinal symptoms in Australia 4 ; therefore, humans may be a true host for this amoeba. This observation has made the differentiation of the three species in clinical samples of great importance, both for diagnosis and for epidemiological studies.…”

“…6,8 However, most studies that have investigated the prevalence of E. histolytica and E. dispar have not considered the possible presence of E. moshkovskii , due partly to a lack of tools to detect E. moshkovskii other than cultivation, 12 which is laborintensive, not always successful, and problematic in the case of mixed infections. Recently, conventional PCR assays for E. moshkovskii in clinical diagnosis of amoebiasis have been performed 3,4,13,14 but most of the protocols reported so far require further processing of the amplicon, which is timeconsuming and prone to false-positive results caused by possible cross-contamination.…”