South American Entamoeba dispar strains produce amoebic liver abscesses with different pathogenicities and evolutionary kinetics.

Amoebiasis is a protozoan disease caused by Entamoeba histolytica, and presents a geographic distribution of worldwide amplitude, high incidence, sometimes accompanied by severe clinical manifestations such as amoebic colitis and Amoebic Liver Abscess (ALA), remaining as a public health problem in developing countries. Entamoeba dispar is another species of amoeba that infects approximately 12% of the world's population, and it has previously been classified as noninvasive. However, E. dispar has already been isolated from patients with symptomatic non-dysenteric colitis, as well as its DNA sequences were detected and genotyped in samples from patients with dysenteric colitis, and patients with ALA, suggesting that this species could also be involved in the development of lesions in the large intestine and liver of human beings. In this context, this study aims to evaluate the ability of isolated strains of Entamoeba dispar in South America to cause liver damage, and to better characterize histopathological findings in 3, 8, 12 and 16 days after infection (DAI). Firstly, we assessed whether trophozoites from MCR, ACFN, ICS, ADO and VEJ E. dispar strains, and EGG Entamoeba histolytica strain differed in their in vitro phagocytosis ability, being related to greater ability to phagocyte with greater virulence. Then, we investigate and characterize histopathological changes present in the liver of mice induced by different strains of E. dispar. Our results demonstrated that trophozoites from E. dispar strains are capable of phagocyting human erythrocytes, but in lower amounts than Entamoeba histolytica. In addition, we described and characterized the lesions in different periods after infection by different E. dispar strains, and identified ACFN as the most pathogenic strain, followed by MCR. The large areas of necrosis produced by the ACFN strain as the eighth DAI, which also show high parasitism, led to 100% mortality. On the other hand, the ICS, ADO and VEJ strains did not produce mortality, and this was correlated with the presence of well-developed chronic granulomatous inflammation, necrosis absorption throughout the infection, and regeneration of the liver parenchyma. The greater pathogenicity of the ACFN strain strongly suggests that this strain could be producing higher levels of virulence factors. As the experimental infection, the heterogeneity of biological behavior of different Entamoeba dispar strains could be involved in the development of undiagnosed human clinical conditions.

Molecular identification of Entamoeba histolytica, E. dispar, and E. moshkovskii in children with diarrhea from Maracaibo, Venezuela / [Identificación molecular de Entamoeba histolytica, Entamoeba dispar y Entamoeba moshkovskii en niños con diarrea en Maracaibo, Venezuela].

Introduction: Entamoeba histolytica is an amebiasis-producing parasite. However, Entamoeba dispar, Entamoeba moshkovskii, and Entamoeba bangladeshi are nonpathogenic amoebae morphologically identical to it and, therefore, molecular techniques are required for their differentiation. Objective: To determine the frequency of Entamoeba species by polymerase chain reaction (PCR) in fecal samples from children under five years with diarrhea from Maracaibo (Venezuela). Materials and methods: A fecal sample per individual was collected from 75 children with diarrhea (case group) and 25 children without diarrhea (control group). Stools were evaluated by microscopic examination, formol-ether concentration method, and nested multiplex PCR in a single round for the identification of E. histolytica, E. dispar, and E. moshkovskii. In addition, a survey was conducted in which demographic data, signs, clinical manifestations, and socioeconomic status were registered. Results: In total, 48% of the children (38 from the case group and 10 from the control group) had intestinal parasites. Only four children presented cysts of the Entamoeba complex in their samples (three from the case group and one from the control group). By means of PCR, nine samples (9%) amplified for the studied amoebae. In the case group, three (28.13%) amplified for E. histolytica, four (30.50%) for E. dispar, and one (9.37%) for E. moshkovskii while only one (25%) sample amplified for E. dispar in the control group. Conclusion: In general, E. dispar predominated. Nevertheless, all those infected with E. histolytica were detected within the group of children with diarrhea and we reported the first case of E. moshkovskii in the region.

Introducción. Las amebas no patógenas Entamoeba dispar, Entamoeba moshkovskii y Entamoeba bangladeshi son morfológicamente idénticas a Entamoeba histolytica, parásito responsable de la amebiasis, por lo cual se necesitan técnicas moleculares para diferenciarlas. Objetivo. Determinar la frecuencia de las diferentes especies de Entamoeba mediante reacción en cadena de la polimerasa (Polymerase Chain Reaction, PCR) en muestras fecales de niños menores de cinco años con diarrea, provenientes de Maracaibo (Venezuela). Materiales y métodos. Se recolectó una muestra fecal por individuo en 75 niños con diarrea (grupo de casos) y en 25 niños sin diarrea (grupo control). Las heces se evaluaron mediante examen microscópico, método de concentración de formól-éter y PCR múltiple anidada en una sola ronda para identificar E. histolytica, E. dispar y E. moshkovskii. Además, se hizo una encuesta en la que se recopilaron los datos demográficos, signos, manifestaciones clínicas y estrato socioeconómico de los niños. Resultados. El 48 % de los participantes (38 del grupo de casos y 10 del grupo de control) tenían enteroparásitos. Solo en las muestras de cuatro de los niños, se encontraron quistes del complejo Entamoeba (tres en el grupo de casos y uno en el de control). Mediante PCR se amplificaron nueve muestras (9 %) para la detección de las amebas estudiadas. En el grupo de casos se registraron tres (28,13 %) de E. histolytica, cuatro (30,50 %) de E. dispar y una (9,37 %) de E. moshkovskii, en tanto que solo una (25 %) muestra amplificó para E. dispar en el grupo de control. Conclusión. En general, predominó E. dispar; sin embargo, todos los infectados con E. histolytica se detectaron en el grupo de niños con diarrea y se detectó el primer caso de E. moshkovskii en la región.

Diversity, geographical distribution, and prevalence of Entamoeba spp. in Brazil: a systematic review and meta-analysis.

The genus Entamoeba includes a variety of widely distributed species adapted to live in the digestive tracts of humans and a large variety of animals of different classes. The objective of this study was to investigate the prevalence, distribution, and molecular epidemiology of Entamoeba spp. in different classes of hosts in Brazil. Studies that analyzed hosts from several classes, including humans and domestic, wild, or captive animals, were considered. The pooled prevalence of Entamoeba spp. was calculated using the random-effects model. A total of 166 studies on humans and 16 on animals were included. The prevalence of Entamoeba spp. in the Brazilian population was 22% (95% CI: 21-24). The state with the highest prevalence was Paraiba with 72%, followed by Federal District with 53%, and Rondonia with 50%. In immunocompromized patients, the prevalence was 18%, and cancer (36%) was the most prevalent cause of immunosuppression. The prevalence of Entamoeba spp. in animal hosts was 12% (95% CI: 7-17). Captive wild animals and domestic farm animals showed the highest prevalence, with 16% and 15%, respectively. The species found more often were E. coli (86.5%), E. dispar (7.9%), and E. histolytica (3.1%). In conclusion, a high prevalence (22%) of Entamoeba spp. was found in the Brazilian population, with a prevalence of up to 50% mainly in the northern, northeastern, and central-western regions. The pathogenic species E. histolytica is distributed in most Brazilian regions, with significant prevalence percentages. Among animals, unidentified Entamoeba species were most prevalent in mammals.

TITLE: Diversité, répartition géographique et prévalence d'Entamoeba spp. au Brésil : revue systématique et méta-analyse. ABSTRACT: Le genre Entamoeba comprend une variété d'espèces largement distribuées, adaptées à vivre dans le tube digestif des humains et une grande variété d'animaux de différentes classes. L'objectif de cette étude était d'étudier la prévalence, la distribution et l'épidémiologie moléculaire d'Entamoeba spp. dans différentes classes d'hôtes au Brésil. Les études qui ont analysé les hôtes de plusieurs classes, y compris les humains et les animaux domestiques, sauvages ou captifs, ont été prises en compte. La prévalence combinée d'Entamoeba spp. a été calculée à l'aide du modèle à effets aléatoires. Au total, 166 études sur l'homme et 16 sur les animaux ont été incluses. La prévalence d'Entamoeba spp. dans la population brésilienne était de 22 % (IC à 95 % : 21­24). L'état avec la prévalence la plus élevée était Paraiba avec 72 %, suivi du District fédéral avec 53 % et Rondonia avec 50 %. Chez les patients immunodéprimés, la prévalence était de 18 % et le cancer (36 %) était la cause la plus fréquente d'immunosuppression. La prévalence d'Entamoeba spp. chez les hôtes animaux était de 12 % (IC à 95 % : 7­17). Les animaux sauvages en captivité et les animaux domestiques d'élevage ont affiché la prévalence la plus élevée, avec respectivement 16 % et 15 %. Les espèces trouvées le plus souvent étaient E. coli (86,5 %), E. dispar (7,9 %) et E. histolytica (3,1 %). En conclusion, une prévalence élevée (22 %) d'Entamoeba spp. a été trouvée dans la population brésilienne, allant jusqu'à 50 % principalement dans les régions du nord, du nord-est et du centre-ouest. L'espèce pathogène E. histolytica est répartie dans la plupart des régions du Brésil, avec des pourcentages de prévalence importants. Parmi les animaux, les espèces d'Entamoeba non identifiées étaient les plus répandues chez les mammifères.

Epidemiology, species composition and genetic diversity of tetra- and octonucleated Entamoeba spp. in different Brazilian biomes.

BACKGROUND: Entamoeba species harbored by humans have different degrees of pathogenicity. The present study explores the intra- and interspecific diversity, phylogenetic relationships, prevalence and distribution of tetra- and octonucleated cyst-producing Entamoeba in different Brazilian regions. METHODS: Cross-sectional studies were performed to collect fecal samples (n = 1728) and sociodemographic data in communities located in four Brazilian biomes: Atlantic Forest, Caatinga, Cerrado, and Amazon. Fecal samples were subjected to molecular analysis by partial small subunit ribosomal DNA sequencing (SSU rDNA) and phylogenetic analysis. RESULTS: Light microscopy analysis revealed that tetranucleated cysts were found in all the studied biomes. The highest positivity rates were observed in the age group 6-10 years (23.21%). For octonucleated cysts, positivity rates ranged from 1 to 55.1%. Sixty SSU rDNA Entamoeba sequences were obtained, and four different species were identified: the octonucleated E. coli, and the tetranucleated E. histolytica, E. dispar, and E. hartmanni. Novel haplotypes (n = 32) were characterized; however, new ribosomal lineages were not identified. The Entamoeba coli ST1 subtype predominated in Atlantic Forest and Caatinga, and the ST2 subtype was predominant in the Amazon biome. E. histolytica was detected only in the Amazon biome. In phylogenetic trees, sequences were grouped in two groups, the first containing uni- and tetranucleated and the second containing uni- and octonucleated cyst-producing Entamoeba species. Molecular diversity indexes revealed a high interspecific diversity for tetra- and octonucleated Entamoeba spp. (H ± SD = 0.9625 ± 0.0126). The intraspecific diversity varied according to species or subtype: E. dispar and E. histolytica showed lower diversity than E. coli subtypes ST1 and ST2 and E. hartmanni. CONCLUSIONS: Tetra- and octonucleated cyst-producing Entamoeba are endemic in the studied communities; E. histolytica was found in a low proportion and only in the Amazon biome. With regard to E. coli, subtype ST2 was predominant in the Amazon biome. The molecular epidemiology of Entamoeba spp. is a field to be further explored and provides information with important implications for public health.

Evaluation of Giardia intestinalis, Entamoeba histolytica and Cryptosporidium hominis/Cryptosporidium parvum in human stool samples by the BD MAXTM Enteric Parasite Panel.

Although the microscopic examination of stool samples remains the reference method of choice for the diagnosis of intestinal protistan infections, this method is time-consuming and requires experienced and well-trained operators. The purpose of this study was to evaluate the level of agreement between the BD MAX TM Enteric Parasite Panel (EPP) and microscopy for the detection of Giardia intestinalis (Lambl, 1859), Cryptosporidium spp. and Entamoeba histolytica Schaudinn, 1903 in stool samples. The study included faecal samples of 362 patients who were admitted to our hospital due to gastrointestinal complaints. In the microscopic examination, which was made with the native-lugol method on the stool samples that were taken from the patients, cysts, trophozoites and eggs of the parasite were examined. The diagnosis of G. intestinalis, Cryptosporidium parvum Tyzzer, 1912 and Cryptosporidium hominis Morgan-Ryan, Fall, Ward, Hijjawi, Sulaiman, Fayer, Thompson, Olson, Lal et Xiao, 2002, and E. histolytica was made in the faecal samples using the EPP assay. In the microscopic examination, Cryptosporidium spp. positive stool samples were stained with kinyoun's acid-fast. In the microscopic examination, parasites were detected in 41 (11%) of the 362 stool samples. In contrast, EPP assay identified parasites in 23 (6.3%) of the samples. In the microscopic examination, E. histolytica and Entamoeba dispar Brumpt, 1925 were detected in 22 (6.1%) of the samples, G. intestinalis was seen in 15 (4.1%), and C. parvum or C. hominis were detected in three (0.8%); these values were five (1.4%), 16 (4.4%) and two (0.5%) positive with the EPP assay. Although C. parvum or C. hominis were detected as positive in the microscopic examination of three samples, only two of the samples were positive in both EPP assay and kinyoun's acid-fast method. The EPP assay is a relatively simple test that can distinguish E. histolytica and E. dispar, but it cannot replace microscopy in the diagnosis of amoebiasis. Diagnosis for G. intestinalis and C. parvum/C. hominis with the BD MAXTM enteric parasite panel was equivalent to that with microscopy. We believe that E. histolytica must be diagnosed with nucleic acid amplification tests that have a high sensitivity and specificity like EPP assay in certain patient groups.

Occurrence and genetic identifications of porcine Entamoeba, E. suis and E. polecki, at Tangerang in West Java, Indonesia.

Entamoeba suis and E. polecki subtype (ST) 1 and ST3 recently have been inferred to be virulent in pigs. However, because relevant molecular epidemiological surveys have been limited, the prevalences of these species remain unknown and their pathogenicities are still controversial. We surveyed 196 fecal samples of pigs (118 of adults, 78 of piglets) at Tangerang in West Java, Indonesia, in 2017, employing PCR using porcine Entamoeba-specific primers. E. suis was the more frequently detected species, observed in 81.1% of samples, while E. polecki ST1 and ST3 were detected in 18.4% and 17.3% of samples, respectively; mixed infections (harboring 2-3 species or subtypes of Entamoeba) were confirmed in 29.3% of positive samples. Statistically significant differences in the positive rates were not seen between adult pigs and piglets, except for those of E. polecki ST3. The prevalences of Eimeria spp. and/or Cystoisospora suis (79.1%), strongyles (55.6%), and Strongyloides spp. (6.1%) were also observed morphologically in the samples. Further chronological or seasonal investigations of pigs and humans in these high-prevalence areas are needed to assess the virulence of the Entamoeba parasites, including the effects on pig productivity, and to evaluate the zoonotic impacts of these organisms.

Endoparasitism of Greek ostriches: First report of Entamoeba struthionis and Balantioides coli.

Ostrich farming is a worldwide practice and an internationally developing industry. Among challenges in livestock production are the parasitic infections. The present study aimed to the investigation of the gastrointestinal parasites biota and prevalence in ostriches raised in different areas of Greece. A total of 141 clinically healthy ostriches originating from four different localities of Greece were coprologically examined for parasites of the gastrointestinal tract. Coprological examination revealed a considerably high rate of infection (65.9%) with protozoa; however, no helminths (trematodes, cestodes and nematodes) were detected. In detail, cysts of Entamoeba struthionis have been found in 57.4% of the examined birds. Moreover, 39.0% of sampled ostriches harboured cysts of Balantioides coli (syn. Balantidium coli), while oocysts of Cryptosporidium sp. were detected at a low percentage (2.1%). Partial sequences of the small subunit rRNA (16S rRNA) gene and the ITS region were amplified from pooled Entamoeba and Balantioides positive samples, respectively, confirming for the first time the presence of Entamoeba struthionis and Balantioides coli in ostriches in Greece. Some of these parasitoses require attention as they may affect productivity performance of the animals in commercial ostrich farming and possibly pose disease risk for livestock and humans.

A Comprehensive Retrospective Study: Intestinal Parasites in Human in Van Province

Objective: The aim of present study was to retrospectively determine the prevalence of intestinal parasites in patients, who were referred to Parasitology Laboratory in Van Yüzüncü Yil University, Faculty of Medicine during an 11-year period. Methods: Stool samples of 69633 individuals admitted to the outpatient clinics in the hospital were initially evaluated with native-Lugol, and then by flotation, sedimentation, trichrome staining, modified acid-fast staining and ELISA methods. Results: Twenty-four parasite species were identified in parasite-positive patients. At least one or more parasite species were found in 34.1% of all patients. The most commonly observed parasite was Blastocystis hominis (26.5%). Among pathogen parasites, Giardia intestinalis (G. intestinalis) was detected in 9.3%, Ascaris lumbricoides (A. lumbricoides) was detected in 2.5%, Entamoeba histolytica/Entamoeba dispar in 0.8%, Cystoisospora belli in 0.004%, Fasciola hepatica in 0.04%, Dicrocoelium dendriticum in 0.001%, Strongyloides stercoralis in 0.001% and hookworm in 0.001% of the patients. Conclusion: It was determined that, pathogen parasites such as G. intestinalis and A. lumbricoides were still observed at high rates in Van province, especially in children, and the problem of parasitosis is still continuing, although the prevalence of parasites has declined when compared to the previous years.

Molecular identification of Entamoeba histolytica from stool samples of Ilam, Iran.

INTRODUCTION: Amoebiasis is a multifactorial, life-threatening public health issue and the third parasitic disease cause of mortality in worldwide, particularly in low- and mid-income countries. The aim of this study was to attempt to explore genetic encoding differences of CP8 (conserved gene) of Entamoeba histolytica/Entamoeba dispar in its various infectious properties isolated from Ilam located at a southwest part of Iran. MATERIALS AND METHODS: A total of 2023 stool samples were collected between 2016 and 2018 from the hospital in Ilam, of which only 30 isolates were identified as E. histolytica/E. dispar. These isolates were collected from the intensive care unit, infectious disease, and surgery settings. The isolates were identified and the polymerase chain reaction (PCR) was performed to detect the CP8 gene. In all stages, Entamoeba histolytica HM1: IMSS was used as a positive control. RESULTS: In genotype confirmation, only two isolates had the CP8 gene found in the PCR technique. The sequencing results confirmed the mentioned gene with 99%-100% specificity. CONCLUSION: It is concluded that PCR is highly sensitive to detect E. histolytica and indicating this important role as screening tools in direct DNA extraction from stool samples and valuable technique in early detection of symptomatic and asymptomatic E. histolytica patients.

Entamoeba infections and associated risk factors among migrant workers in Peninsular Malaysia.

The influx of low skilled migrant workers to Malaysia from low socio-economic countries where gastrointestinal parasitic infections are prevalent has raised concerns about transmission to the local population. Three methods for detection (serology, microscopy and molecular techniques) were utilized to identify Entamoeba infections amongst the targeted cohort and determine risk factors associated with infection. Serological screening of 484 migrant workers from five working sectors in Peninsular Malaysia using IgG4 ELISA based on the rPPDK antigen showed an overall seroprevalence of 7.4% (n = 36; CL95 = 5.3-10.1%) with only one factor statistically associated with seropositivity of anti-amoebic antibodies, i.e. years of residence in Malaysia (χ2 1 = 4.007, p = 0.045). Microscopic examination of 388 faecal samples for protozoan cysts and trophozoites showed a slightly higher prevalence (11.6%; n=45; CL95: 8.4-14.8%). Meanwhile, amplification of the 16S rDNA gene detected two species i.e. Entamoeba dispar (23/388; 5.9%; CL95: 3.6-8.3%) and E. histolytica (11/388; 2.8%; CL95: 1.2-4.5%) and mixed infections with both parasites in only three samples (3/388; 0.8%; CL95: 0.2-2.2%). Entamoeba dispar infection was significantly associated with those employed in food and domestic services (χ2 4 = 12.879, p = 0.012). However, none of the factors affected the prevalence of E. histolytica infection. Despite the low prevalence of E. histolytica in faecal samples of the study cohort, the presence of this pathogenic parasite still poses potential public health risks and calls for tighter control strategies based on better availability of chemotherapeutic treatment and accessibility to appropriate health education.

Enteroparasites, demographic profile, socioeconomic status and education level in the rural population of the Recôncavo of Bahia, Brazil

Demographic and social studies, as well as economic and cultural factors in a community are important regarding public health. This study identified demographic, socioeconomic and cultural aspects correlated with intestinal parasites in the population of Santo Antônio de Jesus, Bahia-Brazil, from July to October 2015. 53 semi-structured questionnaires were applied to the rural population of the municipality with previous clarification on the purpose of the study. There were questions related to the individual's gender, family income and parental level of education. Laboratory parasitological analyzes were performed to investigate enteroparasites and produced the following results: 53.7% (n=58) were female; 62.8% (n=66) with monthly family income lower or equal to the minimum wage and 48% (n=48) of adults with incomplete basic education. The main enteroparasites found in this population were: Iodamoeba butschlii, Entamoeba histolytica/Entamoeba dispar complex, Giardia intestinalis, Entamoeba coli and Endolimax nana in addition to some geohelminths, such as hookworms and Enterobius vermicularis. The profile visualized can be understood as a risk factor for the development of certain parasitic infections that are intrinsically associated to the social and economic aspects of vulnerable populations.

Prevalence of non-pathogenic types of gastrointestinal protozoa in population in Slovakia and their potential importance in the aspect of public health.

The aim of the research was to determine the prevalence of non-pathogenic protozoa circulating in the human population of Slovakia. We particularly focused on the socially deprived areas with poor sanitation conditions, as they are one of the factors affecting the transmission of these infections. Within this study, 2760 people were coprologically screened for the presence of protozoan cysts. The analyzed group comprised 1173 men and 1587 women from different regions of Slovakia. The total prevalence (2.03%) of non-pathogenic protozoa species was determined. The prevalence of Entamoeba coli was 0.80%, the prevalence of Endolimax nana 0.58%, and the prevalence of Blastocystis hominis was 0.65%. The presence of non-pathogenic protozoa was more frequent in women than that in men, in all age groups. The highest incidence of Entamoeba coli was found in children aged one month - seven years (0.79%), the lowest in the age group of 19-88 years (0.66%). Endolimax nana was most frequent in 8-18 year-olds (0.95%), where the statistical significance was found (p<0.05). The prevalence of Blastocystis hominis by the age group ranged from 0.39 to 0.95%. We did not find any statistical significance (p>0.05) for Entamoeba coli, and similarly for Blastocystis hominis associated with the sex and age. Although the circulation of non-pathogenic protozoa in the human population is far from being limited to the developing countries, their occurrence is also frequent in the population of developed countries. Despite their controversial pathogenicity, they should not be neglected, particularly in the patients with gastrointestinal symptoms.

Evaluation of a PCR Method for Detection of Entamoeba polecki, with an Overview of Its Molecular Epidemiology.

Entamoebapolecki is a parasite of human and nonhuman primates, other mammals, and birds. Due to overlapping morphological features, cysts of E. polecki may be confused with those of other Entamoeba species commonly found in human fecal samples, including immature cysts of Entamoeba histolytica Although the presence of E. polecki in human Entamoeba-positive stool samples may be rare, its prevalence is likely underestimated due to such confusion. Here, we give examples of diagnostic approaches applied so far and summarize data on the molecular epidemiology of E. polecki, including host specificity and phylogeography. Moreover, we evaluate a novel diagnostic conventional PCR developed for the screening of fecal samples for E. polecki The assay was highly sensitive and specific when used on genomic DNA extracted directly from stool and Swedish wastewater samples. The PCR enabled the identification of all four subtypes (ST1 to ST4) of E. polecki by PCR product sequencing. Most (23/28) subtyped E. polecki-positive samples detected in patients in Sweden between 2002 and 2015 reflected colonization by ST4 and were seen in travelers/foreigners. Two and three human cases of ST2 and ST3, respectively, were also detected. Subtypes 1, 2, and 3 were detected in 3/21 wastewater samples, suggesting local endemicity of these E. polecki subtypes; interestingly, ST4 was not detected in wastewater. In conclusion, the current PCR assay enables simple and cost-effective screening of fecal and wastewater samples for E. polecki Human cases of E. polecki appear to involve primarily ST4, while E. polecki detected in wastewater may be primarily of animal origin.

First detection and molecular identification of Entamoeba bovis from Japanese cattle.

Thus far, Entamoeba species have been classified based on morphology such as the number of nuclei in mature cysts and their hosts. Using recently developed molecular tools, ruminant Entamoeba spp. are currently classified into four species/genotypes: E. bovis and Entamoeba ribosomal lineages (RL) 1, 2, and 4. However, the distribution or pathogenicity of ruminant Entamoeba has not been well documented. In the present study, we examined a total of 25 fecal and seven environmental samples collected from six farms in Japan from 2016 to 2017 by the floatation method and PCR and sequencing analyses. Consequently, we detected Entamoeba cysts in 18 of 25 cattle samples and four of the seven environmental samples, including soil and drinking water, by microscopic examinations. In sequential examinations, Entamoeba-positive cattle were found to shed cysts without any clinical symptoms for more than 8 months. By PCR for molecular identification, isolates in ten cattle and one soil sample were successfully sequenced and formed a cluster of E. bovis, which was separated from those of other Entamoeba species/genotypes such as RL1-4 in phylogenetic analysis. To our knowledge, this is the first report about E. bovis in Japan, and our results may implicate that E. bovis is not pathogenic.

First molecular epidemiology of Entamoeba histolytica, E. dispar and E. moshkovskii infections in Yemen: different species-specific associated risk factors.

OBJECTIVES: To investigate the molecular epidemiology of Entamoeba histolytica, E. dispar and E. moshkovskii infections among rural communities in Yemen. METHODS: In a community-based study, faecal samples were collected from 605 participants and examined by wet mount, formalin-ether sedimentation, trichrome staining and nested multiplex PCR techniques. Demographic, socio-economic and environmental information was collected using a pre-tested questionnaire. RESULTS: Overall, 324 (53.6%) of the samples were positive for Entamoeba cysts and/or trophozoites by microscopic examination. Molecular analysis revealed that 20.2%, 15.7% and 18.2% of the samples were positive for E. histolytica, E. dispar and E. moshkovskii, respectively. Multivariate analysis showed different sets of species-specific risk factors among these communities. Educational level was identified as the significant risk factor for E. histolytica; age and gender were the significant risk factors for E. moshkovskii; and sources of drinking water and consumption of unwashed vegetables were the significant risk factors for E. dispar. Moreover, living in coastal/foothill areas and presence of other infected family members were risk factors for both E. histolytica and E. moshkovskii infections. CONCLUSION: The study reveals that Entamoeba spp. infection is highly prevalent among rural communities in Yemen, with E. histolytica, E. dispar and E. moshkovskii differentiated for the first time. Identifying and treating infected family members, providing health education pertinent to good personal and food hygiene practices and providing clean drinking water should be considered in developing a strategy to control intestinal parasitic infections in these communities, particularly in the coastal/foothill areas of the country.

Morphological and molecular characterization of an uninucleated cyst-producing Entamoeba spp. in captured Rangeland goats in Western Australia.

Uninucleated Entamoeba cysts measuring 7.3×7.7µm were detected in faecal samples collected from wild Rangeland goats (Capra hircus) after arrival at a commercial goat depot near Geraldton, Western Australia at a prevalence of 6.4% (8/125). Sequences were obtained at the 18S rRNA (n=8) and actin (n=5) loci following PCR amplification. At the 18S locus, phylogenetic analysis grouped the isolates closest with an E. bovis isolate (FN666250) from a sheep from Sweden with 99% similarity. At the actin locus, no E. bovis sequences were available, and the isolates shared 94.0% genetic similarity with E. suis from a pig in Western Japan. This is the first report to describe the morphology and molecular characterisation of Entamoeba from Rangeland goats in Western Australia and the first study to produce actin sequences from E. bovis-like Entamoeba sp.

Effect of Mass Stool Examination and Mass Treatment For Decreasing Intestinal Helminth and Protozoan Infection Rates in Bolivian Children: A Cross-Sectional Study.

Bolivia is one of the countries with a high intestinal helminth and protozoan infection rate. Despite the high prevalence of the parasitic infection, nationwide preventive measures for Bolivian children have not yet been implemented. We evaluated the effect of mass stool examination and treatment as a strategy for decreasing the infection rate. This study was conducted between 2013 and 2015 in children aged 2-18 years. A total of 2,033 stool samples (575 in 2013, 815 in 2014 and 642 in 2015) were collected and examined using the formalin-ether medical sedimentation method. As an anthelminthic medicine, nitazoxanide was given to all infected children within 2 months post-examination, each year. The effect of mass stool examination and treatment was evaluated based on the changes in the overall or individual parasitic infection rates during the study period. The overall parasitic infection rate decreased significantly from 65.2% in 2013 to 43.0% in 2015; a 22.2 percentage point decrease (P<0.001). Protozoan infection accounted for a large portion of the parasitic infections, in the following rates: 62.4% in 2013, 49.3% in 2014, and 41.0% in 2015. The rate of the most common helminth infection, Hymenolepis nana, decreased significantly from 9.0% in 2013 to 6.4% in 2014 to 3.4% in 2015 (P<0.001). Prevalence of the most common pathogenic protozoan infection, Entamoeba histolytica, decreased significantly from 19.0% in 2013 to 3.0% in 2015 (P<0.001). Conversely, the rate of Giardia intestinalis increased significantly from 16.5% in 2013 to 21.2% in 2015 (P<0.01). Mass stool examination and treatment for intestinal helminth and protozoan infections was effective for decreasing the overall parasitic infection rate in the study population, excluding Giardia intestinalis. Further studies on the long-term effect of mass stool examination and treatment for decreasing all intestinal parasitic infection rates in Bolivian children are needed.

Identification of Entamoeba histolytica and E. dispar infection in Maceió, Alagoas State, northeast Brazil.

INTRODUCTION: A cross-sectional study was carried out to assess the prevalence of E. histolytica and E. dispar by examining stool samples obtained from 1,003 students of public schools in Maceió, Alagoas, Brazil. METHODOLOGY: All stool samples were processed using the spontaneous sedimentation technique and examined microscopically for the presence of Entamoeba species. In order to distinguish infections caused by E. histolytica, fecal samples presenting cysts of Entamoeba were subjected to specific enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). RESULTS: The analysis of the fecal specimens by microscopy identified 6.4% (64/1,003) students positive for E. histolytica/E. dispar/E. moshkovskii cysts. The prevalence of E. histolytica detected by ELISA was 3.0% (30/1,003) and by PCR 2.8% (28/1,003), but the difference is not statistically significant (p > 0.05). The prevalence of E. dispar in schoolchildren was 5.0% (50/1,003). Mixed infections with E. histolytica and E. dispar were also detected by PCR.  Even though immunological and molecular methods have shown similar results for identification of E. histolytica, ELISA is advantageous over the PCR since it is relatively cheaper and easier to perform. CONCLUSIONS: Our study demonstrated the occurrence of E. histolytica in Maceió and highlights the need to introduce a specific diagnostic test to detect amoebiasis cases in public laboratories.

Prevalence of intestinal parasitic infections and associated risk factors among schoolchildren in the Plateau Central and Centre-Ouest regions of Burkina Faso.

BACKGROUND: Unsafe drinking water, unimproved sanitation and lack of hygiene pose health risks, particularly to children in low- and middle-income countries. This study aimed to assess the prevalence and risk factors of intestinal parasitic infections in school-aged children in two regions of Burkina Faso. METHODS: A cross-sectional survey was carried out in February 2015 with 385 children aged 8-14 years from eight randomly selected schools in the Plateau Central and Centre-Ouest regions of Burkina Faso. Stool samples were subjected to the Kato-Katz and a formalin-ether concentration method for the diagnosis of helminths and intestinal protozoa infections. Urine samples were examined with a urine filtration technique for Schistosoma haematobium eggs. Water samples from community sources (n = 37), children's households (n = 95) and children's drinking water cups (n = 113) were analysed for contamination with coliform bacteria and faecal streptococci. Data on individual and family-level risk factors were obtained using a questionnaire. Mixed logistic regression models were employed to determine factors associated with intestinal parasitic infections in schoolchildren. RESULTS: Intestinal parasitic infections were highly prevalent; 84.7 % of the children harboured intestinal protozoa, while helminth infections were diagnosed in 10.7 % of the children. We found significantly lower odds of pathogenic intestinal protozoa infection (Entamoeba histolytica/E. dispar and Giardia intestinalis) among children from the Plateau Central, compared to the Centre-Ouest region (P < 0.001). Children from households with "freely roaming domestic animals" (P = 0.008), particularly dogs (P = 0.016) showed higher odds of G. intestinalis, and children reporting exposure to freshwater sources through domestic chores had higher odds of S. haematobium infection compared to children without this water contact activity (P = 0.035). Water quality, household drinking water source and storage did not emerge as significant risk factors for intestinal parasitic infections in children. CONCLUSIONS: Intestinal protozoa but not helminths were highly prevalent among schoolchildren in randomly selected schools in two regions of Burkina Faso. Our findings call for specific public health measures tailored to school-aged children and rural communities in this part of Burkina Faso. It will be interesting to assess the effect of water, sanitation and hygiene interventions on the transmission of intestinal parasitic infections. TRIAL REGISTRATION: ISRCTN17968589 (date assigned: 17 July 2015).

School-based prevalence of intestinal parasitic infections and associated risk factors in rural communities of Sana'a, Yemen.

Yemen is a developing country overwhelmed with a triad of poverty, diseases and social conflicts. Moreover, the majority of its population live in rural communities and suffer from intestinal parasitic infections (IPIs). Therefore, the present school-based, cross-sectional survey aimed to detect the prevalence of such infections and associated risk factors among schoolchildren in the rural communities of Bani Alharith, Hamdan and Bani Hushaysh districts of Sana'a, north of Yemen. Socio-demographic data and certain behavioral risk factors as well as stool samples were collected from 1218 schoolchildren from ten randomly schools in the study area. Fresh stool samples were examined for parasites by direct saline and iodine preparations and after concentration with formol-ether technique. The overall prevalence of IPIs was 54.8%, with a higher frequency of protozoal than helminthic infections (37.6 vs. 17.2%, respectively). Parasite species recovered were Entameba histolytica (21.5%), Giardia lamblia (16.1%), Ascaris lumbricoides (8.3%), Hymenolepis nana (5.3%), Schistosoma mansoni (2.6%), Trichuris trichiura (0.5%) and Enterobius vermicularis (0.4%). Univariate analysis showed that the male gender and illiteracy of fathers and/or mothers were the socio-demographic factors significantly associated with higher infection rates. The illiteracy of mothers was also confirmed as an independent risk factor by multivariable analysis. On the other hand, not washing hands before eating, not washing fruits and vegetables before consumption, eating uncovered food and not clipping fingernails were the risk behaviors significantly associated with higher infection rates, with the last three ones being confirmed as independent risk factors. Therefore, control measures should include regular treatment of protozoal infections and deworming of schoolchildren, promotion of hygiene in rural schools through health education programs, regular inspection of schoolchildren for personal hygiene practices and the provision of a healthy school infrastructure.