Genetic characterization of the Entamoeba moshkovskii population based on different potential genetic markers.

Entamoeba moshkovskii, according to recent studies, appears to exert a more significant impact on diarrhoeal infections than previously believed. The efficient identification and genetic characterization of E. moshkovskii isolates from endemic areas worldwide are crucial for understanding the impact of parasite genomes on amoebic infections. In this study, we employed a multilocus sequence typing system to characterize E. moshkovskii isolates, with the aim of assessing the role of genetic variation in the pathogenic potential of E. moshkovskii. We incorporated 3 potential genetic markers: KERP1, a protein rich in lysine and glutamic acid; amoebapore C (apc) and chitinase. Sequencing was attempted for all target loci in 68 positive E. moshkovskii samples, and successfully sequenced a total of 33 samples for all 3 loci. The analysis revealed 17 distinct genotypes, labelled M1­M17, across the tested samples when combining all loci. Notably, genotype M1 demonstrated a statistically significant association with diarrhoeal incidence within E. moshkovskii infection (P = 0.0394). This suggests that M1 may represent a pathogenic strain with the highest potential for causing diarrhoeal symptoms. Additionally, we have identified a few single-nucleotide polymorphisms in the studied loci that can be utilized as genetic markers for recognizing the most potentially pathogenic E. moshkovskii isolates. In our genetic diversity study, the apc locus demonstrated the highest Hd value and π value, indicating its pivotal role in reflecting the evolutionary history and adaptation of the E. moshkovskii population. Furthermore, analyses of linkage disequilibrium and recombination within the E. moshkovskii population suggested that the apc locus could play a crucial role in determining the virulence of E. moshkovskii.

Development of nucleic acid lateral flow immunoassay for molecular detection of Entamoeba moshkovskii and Entamoeba dispar in stool samples.

Entamoeba moshkovskii, recently known as a possible pathogenic amoeba, and the non-pathogenic Entamoeba dispar are morphologically indistinguishable by microscopy. Although PCR was used for differential diagnosis, gel electrophoresis is labor-intensive, time-consuming, and exposed to hazardous elements. In this study, nucleic acid lateral flow immunoassay (NALFIA) was developed to detect E. moshkovskii and E. dispar by post-PCR amplicon analysis. E. moshkovskii primers were labeled with digoxigenin and biotin whereas primers of E. dispar were lebeled with FITC and digoxigenin. The gold nanoparticles were labeled with antibodies corresponding to particular labeling. Based on the established assay, NALFIA could detect as low as 975 fg of E. moshkovskii target DNA (982 parasites or 196 parasites/microliter), and 487.5 fg of E. dispar target DNA (444 parasites or 89 parasites/microliter) without cross-reactivity to other tested intestinal organisms. After testing 91 stool samples, NALFIA was able to detect seven E. moshkovskii (87.5% sensitivity and 100% specificity) and eight E. dispar samples (66.7% sensitivity and 100% specificity) compared to real-time PCR. Interestingly, it detected three mixed infections as real-time PCR. Therefore, it can be a rapid, safe, and effective method for the detection of the emerging pathogens E. moshkovskii and E. dispar in stool samples.

Molecular Detection of a Pathogenic Entamoeba among Symptomatic Children in Eastern Kurdistan of Iraq.

Entamoeba histolytica infects the large intestine of humans, causing a spectrum of clinical appearances ranging from asymptomatic colonization to severe intestinal and extra-intestinal disease. The parasite is identical microscopically to commensal nonpathogenic amoeba. To detect the pathogenic Entamoeba and estimate the precise prevalence of the parasite among the symptomatic pediatric population using molecular techniques. 323 fecal samples were collected from symptomatic children admitted to Sulaimani Pediatric Teaching Hospital, Sulaimaniyah Province, Iraq, from June to October 2021. A structured, validated questionnaire was prepared and used to report participants' gender, residency, and drinking water source. Then, stool samples were microscopically examined, and the positive samples were submitted to molecular analysis by amplifying the 18s rRNA gene using nested PCR to differentiate E. histolytica from other nonpathogenic Entamoeba. Finally, gene sequences were done to confirm the species. Microscopically, 58 positive samples represented Entamoeba species infection rate of 18% among symptomatic patients. However, only 18 samples were positive for E. histolytica based on molecular methods, which accounts for 31% of the positive by microscopy and 5.6% among the 323 symptomatic populations. NCBI, available in their database, gives the gene sequence and accession number. Patients' sociodemographic data and water sources were directly related to the infection rate. Classical microscopic examination provides a misleading profile about the prevalence of E. histolytica in an endemic region that might lead to unnecessary treatments and a lack of appropriate management for patients.

Genome-Wide Classification of Myb Domain-Containing Protein Families in Entamoeba invadens.

Entamoeba histolytica, the causative agent of amebiasis, is the third leading cause of death among parasitic diseases globally. Its life cycle includes encystation, which has been mostly studied in Entamoeba invadens, responsible for reptilian amebiasis. However, the molecular mechanisms underlying this process are not fully understood. Therefore, we focused on the identification and characterization of Myb proteins, which regulate the expression of encystation-related genes in various protozoan parasites. Through bioinformatic analysis, we identified 48 genes in E. invadens encoding MYB-domain-containing proteins. These were classified into single-repeat 1R (20), 2R-MYB proteins (27), and one 4R-MYB protein. The in-silico analysis suggests that these proteins are multifunctional, participating in transcriptional regulation, chromatin remodeling, telomere maintenance, and splicing. Transcriptomic data analysis revealed expression signatures of eimyb genes, suggesting a potential orchestration in the regulation of early and late encystation-excystation genes. Furthermore, we identified probable target genes associated with reproduction, the meiotic cell cycle, ubiquitin-dependent protein catabolism, and endosomal transport. In conclusion, our findings suggest that E. invadens Myb proteins regulate stage-specific proteins and a wide array of cellular processes. This study provides a foundation for further exploration of the molecular mechanisms governing encystation and unveils potential targets for therapeutic intervention in amebiasis.

Multi-locus sequence analysis reveals phylogenetically segregated Entamoeba histolytica population.

Amoebiasis, caused by the enteric parasite, Entamoeba histolytica, is one of the major food- and water-borne parasitic diseases in developing countries with improper sanitation and poor hygiene. Infection with E. histolytica has diverse disease outcomes, which are determined by the genetic diversity of the infecting strains. Comparative genetic analysis of infecting E. histolytica strains associated with differential disease outcomes from different geographical regions of the world is important to identify the specific genetic patterns of the pathogen that trigger certain disease outcomes of Amoebiasis. The strategy is able to elucidate the genealogical relation and population structure of infecting E. histolytica strains from different geographical regions. In the present study, we have performed a comparative genetic analysis of circulating E. histolytica strains identified from different parts of the world, including our study region, based on five tRNA-linked short tandem repeat (STR) loci (i.e., D-A, NK2, R-R, STGA-D and A-L) and evaluated their potential associations with differential disease outcomes of Amoebiasis. A number of regional-specific, emerging haplotypes of E. histolytica, significantly associated with specific disease outcomes have been identified. Haplotypes, which have a significant positive association with asymptomatic and amoebic liver abscess outcomes, showed a significant negative association with diarrheal outcome, or vice versa. Comparative multi-locus analysis revealed that E. histolytica isolates from our study region are phylogenetically segregated from the isolates of other geographical regions. This study provides a crucial overview of the population structure and emerging pattern of the enteric parasite, E. histolytica.

Short tandem repeat (STR) based sequence typing of Entamoeba histolytica identifies STGA-D locus as a genetic marker, associated with disease outcomes.

Amoebiasis, caused by the enteric parasite Entamoeba histolytica has differential disease outcomes. The association of parasite genotypes with outcomes of amoebic infection is still a paradox and requires to be explored. The genetic information of infecting strains from endemic settings of different geographical regions is essential to evaluate the relation. Comparative genetics of E. histolytica clinical isolates from different disease outcomes have been explored based on two tRNA-linked STR loci (STGA-D and A-L). All of the repeat patterns in the A-L locus were newly identified and unique to Indian isolates. The majority of newly identified repeat patterns in STGA-D locus have outcome-specific distributions, predicting the emergence of disease-specific mutations in this target locus. Statistical analysis further reinforces this observation, as identified repeat patterns only from STGA-D but not A-L locus were significantly associated with disease outcomes. Phylogenetic analysis indicates independent segregation and divergence of tRNA-linked STR arrays for each STR locus.

Metagenomic analysis reveals the relationship between intestinal protozoan parasites and the intestinal microecological balance in calves.

BACKGROUND: A close connection between a protozoan parasite and the balance of the other gut microbes of the host has been demonstrated. The calves may be naturally co-infected with many parasites, and the co-effects of parasites on other intestinal microbes of calves remain unclear. This study aims to preliminarily reveal the relationship between intestinal parasites and other intestinal microbes in calves. METHODS: Fecal samples were collected from four calves with bloody diarrhea, four calves with watery diarrhea, and seven normal calves, and the microbial flora of the samples were analyzed by whole-genome sequencing. Protozoal parasites were detected in the metagenome sequences and identified using polymerase chain reaction (PCR). RESULTS: Cryptosporidium, Eimeria, Giardia, Blastocystis, and Entamoeba were detected by metagenomic analysis, and the identified species were Giardia duodenalis assemblage E, Cryptosporidium bovis, Cryptosporidium ryanae, Eimeria bovis, Eimeria subspherica, Entamoeba bovis, and Blastocystis ST2 and ST10. Metagenomic analysis showed that the intestinal microbes of calves with diarrhea were disordered, especially in calves with bloody diarrhea. Furthermore, different parasites show distinct relationships with the intestinal microecology. Cryptosporidium, Eimeria, and Giardia were negatively correlated with various intestinal bacteria but positively correlated with some fungi. However, Blastocystis and Entamoeba were positively associated with other gut microbes. Twenty-seven biomarkers not only were significantly enriched in bloody diarrhea, watery diarrhea, and normal calves but were also associated with Eimeria, Cryptosporidium, and Giardia. Only Eimeria showed a distinct relationship with seven genera of bacteria, which were significantly enriched in the healthy calves. All 18 genera of fungi were positively correlated with Cryptosporidium, Eimeria, and Giardia, which were also significantly enriched in calves with bloody diarrhea. Functional genes related to parasites and diseases were found mainly in fungi. CONCLUSIONS: This study revealed the relationship between intestinal protozoan parasites and the other calf gut microbiome. Different intestinal protozoan parasites have diametrically opposite effects on other gut microecology, which not only affects bacteria in the gut, but also is significantly related to fungi and archaea.

First molecular detection of Entamoeba gingivalis subtypes in individuals from Turkey.

Entamoeba gingivalis is a parasitic protozoan that colonizes the human oral cavity and there are two subtypes (ST1 and ST2) that have been identified to date. However, there are no reports on the molecular detection or characterization of E. gingivalis in Turkey. The objective of this study was to detect the presence of E. gingivalis in Turkish healthy individuals and those with periodontal disease and to subtype the isolates using molecular techniques. Samples from the oral cavity of 94 individuals were taken and the presence of E. gingivalis was determined by PCR using primers for SsrRNA and the amplicons were then confirmed by DNA sequencing. Each participant completed a questionnaire that included demographic data, habits and lifestyle, as well as health status. The presence of E. gingivalis was detected in a total of 19 samples (11 patients and eight healthy individuals). Molecular characterization determined that 12 samples belonged to ST1 and seven samples belonged to ST2. The presence of E. gingivalis was higher in patients with periodontal disease than in healthy individuals, and this association was statistically significant (P < .05). This study constitutes the first report of molecular detection and subtyping of E. gingivalis in Turkey.

Amoebiasis: Advances in Diagnosis, Treatment, Immunology Features and the Interaction with the Intestinal Ecosystem.

This review of human amoebiasis is based on the most current knowledge of pathogenesis, diagnosis, treatment, and Entamoeba/microbiota interactions. The most relevant findings during this last decade about the Entamoeba parasite and the disease are related to the possibility of culturing trophozoites of different isolates from infected individuals that allowed the characterization of the multiple pathogenic mechanisms of the parasite and the understanding of the host-parasite relationship in the human. Second, the considerable advances in molecular biology and genetics help us to analyze the genome of Entamoeba, their genetic diversity, and the association of specific genotypes with the different amoebic forms of human amoebiasis. Based on this knowledge, culture and/or molecular diagnostic strategies are now available to determine the Entamoeba species and genotype responsible for invasive intestinal or extraintestinal amoebiasis cases. Likewise, the extensive knowledge of the immune response in amoebiasis with the appearance of new technologies made it possible to design diagnostic tools now available worldwide. Finally, the understanding of the interaction between the Entamoeba species and the intestinal microbiota aids the understanding of the ecology of this parasite in the human environment. These relevant findings will be discussed in this review.

First description of Blastocystis sp. and Entamoeba sp. infecting zoo animals in the Qinghai-Tibetan plateau area, China.

Protozoan parasites are a well-known threat to human health, particularly for people working at or visiting zoos, and potentially cause zoonotic diseases in humans. Captive wildlife may be potential reservoirs for human infection with protozoan parasites. Therefore, focusing on zoonotic protozoan infections in zoo animals is critical. However, there is no report on this topic in the Qinghai-Tibetan Plateau region. In this study, a total of 167 and 103 fecal samples were collected from 12 animal species from Qinghai-Tibet Plateau Wildlife Park in winter and summer, respectively, to detection the prevalence of infections and subtype distribution with Entamoeba sp., Cryptosporidium sp., Giardia duodenalis, Enteromicrosporidia bieneusi sp., Blastocystis sp. by PCR assay. The results showed that a total of 21 fecal samples collected in winter, including from 2 white-lipped deer, 8 Sika deer, 6 blue sheep, 2 wolves and 3 bears, were positive for Entamoeba, with a 12.6% (21/167) positive rate. However, 4.9% (5/103) of animals in summer were positive for Entamoeba, including 1 snow leopard, 1 tiger, 1 Tibetan argali and 2 mouflon. Moreover, 1 white-lipped deer and 1 bear were found to be positive for Blastocystis sp., one zoonotic STs (ST10) was identified and found in white-lipped deer. We found no effect on season on Blastocystis sp. and Entamoeba sp. colonization. To the best of our knowledge, this study is the first description of Blastocystis sp. and Entamoeba sp. infecting zoo animals in the plateau area. The findings provide the latest data on Entamoeba sp. and Blastocystis sp. in zoo animals in China.

Correlation of Redondovirus and Entamoeba gingivalis Detections in the Human Oral Cavity Suggests That This Amoeba Is Possibly the Redondovirus Host.

The virome of the human oral cavity and the relationships between viruses and diseases such as periodontitis are scarcely deciphered. Redondoviruses were reported in the human oral cavity in 2019, including in periodontitis patients. Here, we aimed at detecting redondoviruses and at searching for a potential viral host in human saliva. Non-stimulated saliva was collected between December 2020 and June 2021. These samples were tested using real-time PCR regarding the presence of redondovirus and Entamoeba gingivalis DNA. Similarity searches were performed using BLAST against eukaryotic and prokaryotic sequences from GenBank. The redondovirus DNA was detected in 46% of the 28 human saliva samples. In addition, short fragments of redondovirus genomes were detected in silico within Entamoeba sequences. Finally, Entamoeba gingivalis DNA was detected in 46% of the 28 saliva samples, with a strong correlation between redondovirus DNA and E. gingivalis DNA detections, in 93% of the cases. Regarded together, these findings and previous ones strongly support the presence of redondoviruses in the human oral cavity and their association to E. gingivalis as their likely host.

Using Entamoeba muris To Model Fecal-Oral Transmission of Entamoeba in Mice.

There are several Entamoeba species that colonize humans, but only Entamoeba histolytica causes severe disease. E. histolytica is transmitted through the fecal-oral route to colonize the intestinal tract of 50 million people worldwide. The current mouse model to study E. histolytica intestinal infection directly delivers the parasite into the surgically exposed cecum, which circumvents the natural route of infection. To develop a fecal-oral mouse model, we screened our vivarium for a natural murine Entamoeba colonizer via a pan-Entamoeba PCR targeting the 18S ribosomal gene. We determined that C57BL/6 mice were chronically colonized by Entamoeba muris. This amoeba is closely related to E. histolytica, as determined by 18S sequencing and cross-reactivity with an E. histolytica-specific antibody. In contrast, outbred Swiss Webster (SW) mice were not chronically colonized by E. muris. We orally challenged SW mice with 1 × 105 E. muris cysts and discovered they were susceptible to infection, with peak cyst shedding occurring between 5 and 7 days postinfection. Most infected SW mice did not lose weight significantly but trended toward decreased weight gain throughout the experiment compared to mock-infected controls. Infected mice treated with paromomycin, an antibiotic used against noninvasive intestinal disease, do not become colonized by E. muris. Within the intestinal tract, E. muris localizes exclusively to the cecum and colon. Purified E. muris cysts treated with bovine bile in vitro excyst into mobile, pretrophozoite stages. Overall, this work describes a novel fecal-oral mouse model for the important global pathogen E. histolytica. IMPORTANCE Infection with parasites from the Entamoeba genus are significantly underreported causes of diarrheal disease that disproportionally impact tropical regions. There are several species of Entamoeba that infect humans to cause a range of symptoms from asymptomatic colonization of the intestinal tract to invasive disease with dissemination. All Entamoeba species are spread via the fecal-oral route in contaminated food and water. Studying the life cycle of Entamoeba, from host colonization to infectious fecal cyst production, can provide targets for vaccine and drug development. Because there is not an oral challenge rodent model, we screened for a mouse Entamoeba species and identified Entamoeba muris as a natural colonizer. We determine the peak of infection after an oral challenge, the efficacy of paromomycin treatment, the intestinal tract localization, and the cues that trigger excystation. This oral infection mouse model will be valuable for the development of novel therapeutic options for Entamoeba infections.

Stress Response in Entamoeba histolytica Is Associated with Robust Processing of tRNA to tRNA Halves.

tRNA-derived fragments have been reported in many different organisms and have diverse cellular roles, such as regulating gene expression, inhibiting protein translation, silencing transposable elements, and modulating cell proliferation. In particular, tRNA halves, a class of tRNA fragments produced by the cleavage of tRNAs in the anti-codon loop, have been widely reported to accumulate under stress and regulate translation in cells. Here, we report the presence of tRNA-derived fragments in Entamoeba, with tRNA halves being the most abundant. We further established that tRNA halves accumulate in the parasites upon different stress stimuli such as oxidative stress, heat shock, and serum starvation. We also observed differential expression of tRNA halves during developmental changes of trophozoite-to-cyst conversion, with various tRNA halves accumulating during early encystation. In contrast to other systems, the stress response does not appear to be mediated by a few specific tRNA halves, as multiple tRNAs appear to be processed during the various stresses. Furthermore, we identified some tRNA-derived fragments associated with Entamoeba Argonaute proteins, EhAgo2-2 and EhAgo2-3, which have a preference for different tRNA-derived fragment species. Finally, we show that tRNA halves are packaged inside extracellular vesicles secreted by amoebas. The ubiquitous presence of tRNA-derived fragments, their association with the Argonaute proteins, and the accumulation of tRNA halves during multiple different stresses, including encystation, suggest a nuanced level of gene expression regulation mediated by different tRNA-derived fragments in Entamoeba. IMPORTANCE In the present study, we report for the first time the presence of tRNA-derived fragments in Entamoeba. tRNA-derived fragments were identified by bioinformatics analyses of small-RNA sequencing data sets from the parasites and also confirmed experimentally. We found that tRNA halves accumulated in parasites exposed to environmental stress or during the developmental process of encystation. We also found that shorter tRNA-derived fragments are bound to Entamoeba Argonaute proteins, indicating that they may have a potential role in the Argonaute-mediated RNA-interference pathway, which mediates robust gene silencing in Entamoeba. We noticed that in response to heat shock, the protein translation levels were elevated in the parasites. This effect was reversed in the presence of an analog of leucine, which also reduced the levels of the tRNA halves in the stressed cells. Our results suggest that tRNA-derived fragments in Entamoeba have a possible role in regulating gene expression during environmental stress.

Further insight into the genetic diversity of Entamoeba coli and Entamoeba hartmanni.

Despite the species' wide distribution, studies of the genetic diversity within Entamoeba coli and Entamoeba hartmanni remain limited. In the present study, we provide further insight into the genetic diversity of both species based on analysis of partial nuclear small subunit ribosomal DNA sequences generated from human fecal DNAs from samples collected in Africa, South America, and Europe. Reinforcing the previous recognition that E. coli is a species complex, our data confirm the existence of the two subtypes, ST1 and ST2, previously identified plus, potentially, a new subtype, ST3. While ST1 appears to be genetically quite homogenous, ST2 shows a substantial degree of intrasubtype diversity. ST2 was more common in samples collected outside Europe, whereas ST1 showed no geographical restriction. The potentially novel subtype is represented to date exclusively by sequences from South American and African samples. In contrast to previous reports, our new data also indicate substantial variation in E. hartmanni that could also support the establishment of subtypes within this species. Here, however, no links were identified between subtype and geographical origin.

Widespread, human-associated redondoviruses infect the commensal protozoan Entamoeba gingivalis.

Redondoviruses are circular Rep-encoding single-stranded DNA (CRESS) viruses of high prevalence in healthy humans. Redondovirus abundance is increased in oro-respiratory samples from individuals with periodontitis, acute illness, and severe COVID-19. We investigated potential host cells supporting redondovirus replication in oro-respiratory samples and uncovered the oral amoeba Entamoeba gingivalis as a likely host. Redondoviruses are closely related to viruses of Entamoeba and contain reduced GC nucleotide content, consistent with Entamoeba hosts. Redondovirus and E. gingivalis co-occur in metagenomic data from oral disease and healthy human cohorts. When grown in xenic cultures with feeder bacteria, E. gingivalis was robustly positive for redondovirus RNA and DNA. A DNA proximity-ligation assay (Hi-C) on xenic culture cells showed enriched cross-linking of redondovirus and Entamoeba DNA, supporting E. gingivalis as the redondovirus host. While bacteria are established hosts for bacteriophages within the human virome, this work shows that eukaryotic commensals also contribute an abundant human-associated virus.

Development of a simple PCR-RFLP technique for detection and differentiation of E. histolytica, E. dispar and E. moshkovskii.

Epidemiological studies on amoebic infections are complicated by morphological overlap between the pathogenic E. histolytica, the commensal E. dispar and the amphizoic E. moshkovskii, necessitating molecular identification. The present study developed a simple and economical 18S PCR-RFLP method for the simultaneous detection and differentiation of the three species. PCR products were differentiated by Tat1 restriction digestion generating three different RFLP patterns. Validation was conducted by screening 382 faecal samples from human patients from Kolkata, India, hospitalized for diarrhoea. Analysis indicated that the PCR-RFLP could successfully differentiate between the three species and was confirmed by sequence analysis. This method could prove useful for clinical and epidemiological studies of amoebiasis.

Hypothetical proteins play a role in stage conversion, virulence, and the stress response in the Entamoeba species.

Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and amoebic liver abscess in humans, affecting millions of people worldwide. This pathogen possesses a two-stage life cycle consisting of an environmentally stable cyst and a pathogenic amoeboid trophozoite. As cysts can be ingested from contaminated food and water, this parasite is prevalent in underdeveloped countries and poses a significant health burden. Until recently there was no reliable method for inducing stage conversion in E. histolytica in vitro. As such, the reptilian pathogen, Entamoeba invadens, has long-served as a surrogate. Much remains unclear about stage conversion in these parasites and current treatments for amoebiasis are lacking, as they cause severe side effects. Therefore, new therapeutic strategies are needed. The genomes of these parasites remain enigmatic as approximately 54% of E. histolytica genes and 66% of E. invadens genes are annotated as hypothetical proteins. In this study, we characterized two hypothetical proteins in the Entamoeba species, EIN_059080, in E. invadens, and its homolog, EHI_056700, in the human pathogen, E. histolytica. EHI_056700 has no homolog in the human host. We used an RNAi-based silencing system to reduce expression of these genes in E. invadens and E. histolytica trophozoites. Loss of EIN_059080 resulted in a decreased rate of encystation and an increased rate of erythrophagocytosis, an important virulence function. Additionally, mutant parasites were more susceptible to oxidative stress. Similarly, loss of EHI_056700 in E. histolytica trophozoites resulted in increased susceptibility to oxidative stress and glucose deprivation, but not to nitrosative stress. Unlike the E. invadens mutants, E. histolytica parasites with decreased reduced expression of EHI_056700 exhibited a decreased rate of erythrophagocytosis of and adhesion to host cells. Taken together, these data suggest that these hypothetical proteins play a role in stage conversion, virulence, and the response to stress in the Entamoebae. Since parasites with reduced expression of EHI_056700 show decreased virulence functions and increased susceptibility to physiologically relevant stressors, EHI_056700 may represent a possible therapeutic target for the treatment of amoebiasis.

Assessing the prevalence and risk factors associated with Entamoeba complex infection among the Orang Asli school children in Perak, Malaysia through molecular approach.

This study performed a cross-sectional investigation on the prevalence of Entamoeba complex infection comprising Entamoeba histolytica, Entamoeba dispar, and Entamoeba moshkovskii and their associated risk factors among the Orang Asli school children in three districts in Perak, Malaysia. Stool samples collected from 544 school children aged between 7 and 12 years old were examined through the nested multiplex PCR assay. The univariate and multivariate regression analyses were then carried out to determine the risk factor associated with Entamoeba complex infection. The overall prevalence of Entamoeba complex infections (E. histolytica, E. dispar and E. moshkovskii) was 21.3% (116/544). Most positive school children were infected with E. moshkovskii (10.7%; 58/544), followed by E. dispar (9.0%; 49/544) and E. histolytica (5.0%; 27/544). Not washing their hands after using the toilet was identified as the only significant risk factor for E. histolytica. The significant risk factors associated with E. moshkovskii infection included children within the age of 10-12 years old, with high BMI, living with working and non-educated mothers, no toilet in the house, not washing their hands after using the toilet, and fever. On the other hand, drinking water from the river, well, and rain was associated with a decreased risk of E. dispar infection. In conclusion, this study showed a high prevalence of Entamoeba spp. infections among the Orang Asli school children in Perak, Malaysia. Addressing the identified risk factors coupled with a holistic approach in breaking the transmission of Entamoeba complex can help improve their quality of life.

A landscape of gene regulation in the parasitic amoebozoa Entamoeba spp.

Entamoeba are amoeboid extracellular parasites that represent an important group of organisms for which the regulatory networks must be examined to better understand how genes and functional processes are interrelated. In this work, we inferred the gene regulatory networks (GRNs) in four Entamoeba species, E. histolytica, E. dispar, E. nuttalli, and E. invadens, and the GRN topological properties and the corresponding biological functions were evaluated. From these analyses, we determined that transcription factors (TFs) of E. histolytica, E. dispar, and E. nuttalli are associated mainly with the LIM family, while the TFs in E. invadens are associated with the RRM_1 family. In addition, we identified that EHI_044890 regulates 121 genes in E. histolytica, EDI_297980 regulates 284 genes in E. dispar, ENU1_120230 regulates 195 genes in E. nuttalli, and EIN_249270 regulates 257 genes in E. invadens. Finally, we identified that three types of processes, Macromolecule metabolic process, Cellular macromolecule metabolic process, and Cellular nitrogen compound metabolic process, are the main biological processes for each network. The results described in this work can be used as a basis for the study of gene regulation in these organisms.

First Detection and Molecular Identification of Entamoeba bovis in Farm-Raised Sika Deer from Anhui Province, China.

BACKGROUND: Protozoans of Entamoeba spp. are one of the most common enteric parasites that infect humans and diverse animals including deer. PURPOSE: However, data regarding the prevalence and species/genotypes of Entamoeba spp. in deer in China is scarce. This study investigated the prevalence and species distribution of Entamoeba spp. in sika deer (Cervus nippon) in Anhui Province. METHODS: In our survey, 336 fecal samples were collected from five sika deer farms in different regions of Anhui Province. All samples were examined for the presence of Entamoeba spp. by PCR and phylogenetic analysis of the conserved 18S rRNA gene. RESULTS: 106/336 (31.5%) fecal samples were positive for Entamoeba spp. A statistically significant difference in the prevalence of Entamoeba spp. infection was observed between sampling farms (p < 0.001), and the prevalence of Entamoeba spp. in male and female sika deer showed no significant difference (p > 0.05). Sequence and phylogenetic analysis revealed the single species, E. bovis, was identified in this study. CONCLUSION: This is the first report about the identification of E. bovis in farm-raised sika deer in China, and these results expand our understanding of host range and species distribution of Entamoeba spp. in ruminants.