Detection and molecular identification of Entamoebaspecies in faecal samples from Duhok province, Kurdistan Region, Iraq.

The study involved the estimation of the prevalence of Entamoeba spp. using microscopy and molecular techniques among symptomatic outpatients during April 2021 to March, 2022. Stool samples were collected from 2592 outpatients with amoebiasis symptoms of both sexes and different ages (≤ l to 60). Also, 107 stool samples were taken randomly from asymptomatic individuals and examined microscopically to detect infection with Entamoeba spp. the positive specimens were used for molecular analysis with positive symptomatic samples targeting the 18S rRNA gene by nested PCR. Microscopically 21.68% (562/2592) were positive, for Entamoeba spp. Males showed highest infection rate than females (67.43% vs 32.56%). Ages from 1-10 years showed the highest rate (54.09%), and urban inhabitant had somewhat a higher rate than rural one (58.54% vs 41.45%) which was statistically non-significant(P>0.05). Among asymptomatic individuals, 57% (61/107) were positive for Entamoeba spp. Nested PCR analysis yielded 73% positive samples for Entamoeba spp. with a fragment size of 897 bp. Three fragment sizes were produced, for E. histolytica, E. dispar and E. moshkovskii which were 439, 174 and 553 bps, respectively. Single infection occurred with, E. histolytica in 46%, of symptomatic and 6% of asymptomatic cases, E. dispar in 38% of asymptomatic and 10% of symptomatic cases, E. moshkovskii, reported at very low rate among both groups.

Prevalence, socio-economic, and associated risk factors of oral cavity parasites in children with intellectual disability from Lorestan province, Iran.

Introduction: Children with intellectual disability (ID) often face challenges in maintaining proper oral hygiene due to their motor, sensory, and intellectual impairments, which can lead to compromised oral health; therefore, there is a need to enhance the oral health status of these populations and establish an effective system for administering preventive interventions. Here, we aimed to evaluate the prevalence of Entamoeba gingivalis and Trichomonas tenax among children with ID in Lorestan province, in Western Iran through parasitological and molecular methods. Methods: The current descriptive investigation involved 215 in children with ID and 215 healthy children (non-ID) who were referred to health facilities in Lorestan province, Iran between October 2022 and March 2024. The prevalence of protozoa in the oral cavity was found through the utilization of both microscopic analysis and conventional polymerase chain reaction (PCR) techniques. Results: The total prevalence of the E. gingivalis and T. tenax in children with ID was found to be 87 (40.5%) and 92 (42.8%) through microscopic and PCR methods, respectively. Among the positive samples, 57 (61.9%) and 35 (38.1%) children tested positive for E. gingivalis and T. tenax, respectively. In contrast, among the 215 non-ID children in the control group, 39 (18.1%) and 42 (19.5%) tested positive by microscopic and PCR methods, respectively. Among positive samples in non-ID children, 23 (54.7%) and 19 (45.3%) children were positive for E. gingivalis and T. tenax, respectively. Multiple logistic regression analysis indicated that residing in urban areas, parental education, monthly family income, and tooth brushing p<0.001) were identified as independent risk factors for oral cavity parasites. Conclusion: This study identified a notable prevalence of oral cavity parasites in children with ID in Lorestan province, Western Iran. It is imperative to recognize the primary risk factors associated with these parasites, particularly inadequate teeth brushing, in order to enhance public and oral health strategies for children with ID. Therefore, pediatric dental professionals should remain vigilant regarding these risk factors to effectively recognize and address oral health issues in this population, thereby mitigating the occurrence of oral diseases and infections.

Unveiling risks in healthy food: Vegetables and fruits are linked to the distribution chain of protozoan parasites.

Vegetable and fruit contamination is recognized as a significant parasite transmission route. This review presents the current state of vegetables ad fruits contamination with food-borne parasitic protozoa worldwide. We consider the methodologies and strategies for detecting parasitic stages developed in the last decade and the contamination data. Asia had the highest number of reports (94 studies), followed by Africa (74 studies). At the country level, with 41 studies, Iran had the most reports among other countries, followed by Nigeria (28 studies). According to the studies included in the current review, 41.22% of vegetables and fruits were contaminated with different species of protozoan parasites. Among different continents, Asia accounted for the highest contamination rate of protozoan parasites (57.12%). Giardia spp. (10%) had the highest contamination rate in vegetables and fruits, followed by Entamoeba coli (8%), E. histolytica/dispar (7%), and Cryptosporidium spp. (6%). This study provides essential data for health authorities to develop food safety programs. The presence of protozoan parasites in fruits and vegetables highlights the critical need for maintaining rigorous food safety measures across the entire production and distribution process, particularly in countries that are major producers and distributors of these food items.

Molecular characterization and zoonotic potential of Entamoeba spp., Enterocytozoon bieneusi and Blastocystis from captive wild animals in northwest China.

BACKGROUND: Parasites Entamoeba spp., Enterocytozoon bieneusi and Blastocystis are prevalent pathogens causing gastrointestinal illnesses in animals and humans. Consequently, researches on their occurrence, distribution and hosts are crucial for the well-being of both animals and humans. Due to the confined spaces and frequent interaction between animals and humans, animal sanctuaries have emerged as potential reservoirs for these parasites. In this study, the wildlife sanctuary near the Huang Gorge of the Qinling Mountains in northwest China is chosen as an ideal site for parasite distribution research, considering its expansive stocking area and high biodiversity. RESULTS: We collected 191 fecal specimens from 37 distinct wildlife species and extracted genomic DNA. We identified these three parasites by amplifying specific gene regions and analyzed their characteristics and evolutionary relationships. All the parasites exhibited a high overall infection rate, reaching 90.05%. Among them, seven Entamoeba species were identified, accounting for a prevalence of 54.97%, with the highest infection observed in Entamoeba bovis. In total, 11 Enterocytozoon bieneusi genotypes were discovered, representing a prevalence of 35.08%, including three genotypes of human-pathogenic Group 1 and two novel genotypes (SXWZ and SXLG). Additionally, 13 Blastocystis subtypes were detected, showing a prevalence of 74.87% and encompassing eight zoonotic subtypes. All of the above suggests significant possibilities of parasite transmission between animals and humans. CONCLUSIONS: This study investigated the occurrence and prevalence of three intestinal parasites, enhancing our understanding of their genetic diversity and host ranges in northwest China. Furthermore, the distribution of these parasites implies significant potential of zoonotic transmission, underscoring the imperative for ongoing surveillance and implementation of control measures. These efforts are essential to mitigate the risk of zoonotic disease outbreaks originating from wildlife sanctuary.

Study on intestinal parasitic infections and gut microbiota in cancer patients at a tertiary teaching hospital in Malaysia.

Intestinal parasitic infections (IPIs) can lead to significant morbidity and mortality in cancer patients. While they are unlikely to cause severe disease and are self-limiting in healthy individuals, cancer patients are especially susceptible to opportunistic parasitic infections. The gut microbiota plays a crucial role in various aspects of health, including immune regulation and metabolic processes. Parasites occupy the same environment as bacteria in the gut. Recent research suggests intestinal parasites can disrupt the normal balance of the gut microbiota. However, there is limited understanding of this co-infection dynamic among cancer patients in Malaysia. A study was conducted to determine the prevalence and relationship between intestinal parasites and gut microbiota composition in cancer patients. Stool samples from 134 cancer patients undergoing active treatment or newly diagnosed were collected and examined for the presence of intestinal parasites and gut microbiota composition. The study also involved 17 healthy individuals for comparison and control. Sequencing with 16S RNA at the V3-V4 region was used to determine the gut microbial composition between infected and non-infected cancer patients and healthy control subjects. The overall prevalence of IPIs among cancer patients was found to be 32.8%. Microsporidia spp. Accounted for the highest percentage at 20.1%, followed by Entamoeba spp. (3.7%), Cryptosporidium spp. (3.0%), Cyclospora spp. (2.2%), and Ascaris lumbricoides (0.8%). None of the health control subjects tested positive for intestinal parasites. The sequencing data analysis revealed that the gut microbiota diversity and composition were significantly different in cancer patients than in healthy controls (p < 0.001). A significant dissimilarity was observed in the bacterial composition between parasite-infected and non-infected patients based on Bray-Curtis (p = 0.041) and Jaccard (p = 0.021) measurements. Bacteria from the genus Enterococcus were enriched in the parasite-infected groups, while Faecalibacterium prausnitzii reduced compared to non-infected and control groups. Further analysis between different IPIs and non-infected individuals demonstrated a noteworthy variation in Entamoeba-infected (unweighted UniFrac: p = 0.008), Cryptosporidium-infected (Bray-Curtis: p = 0.034) and microsporidia-infected (unweighted: p = 0.026; weighted: p = 0.019; Jaccard: p = 0.031) samples. No significant dissimilarity was observed between Cyclospora-infected groups and non-infected groups. Specifically, patients infected with Cryptosporidium and Entamoeba showed increased obligate anaerobic bacteria. Clostridiales were enriched with Entamoeba infections, whereas those from Coriobacteriales decreased. Bacteroidales and Clostridium were found in higher abundance in the gut microbiota with Cryptosporidium infection, while Bacillales decreased. Additionally, bacteria from the genus Enterococcus were enriched in microsporidia-infected patients. In contrast, bacteria from the Clostridiales order, Faecalibacterium, Parabacteroides, Collinsella, Ruminococcus, and Sporosarcina decreased compared to the non-infected groups. These findings underscore the importance of understanding and managing the interactions between intestinal parasites and gut microbiota for improved outcomes in cancer patients.

Association of Entamoeba gingivalis with Periodontal Disease-Systematic Review and Meta-Analysis.

The oral cavity is a habitat to a diverse range of organisms that make up an essential element of the human microbiota. There are up to 1000 species of micro-organisms capable of colonizing the mouth. Thirty percent of them are uncultivable. The genus Entamoeba includes several species, out of which at least seven of them are able to inhabit the human body (Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, Entamoeba coli, Entamoeba polecki, Entamoeba hartmann, Entamoeba gingivalis). It was shown that only E. gingivalis is able to colonize the oral cavity. The aim of this study was to evaluate the association and prevalence of E. gingivalis in periodontal disease using two electronic database search engines. In order to have a broader view of the subject, a comprehensive manual search was conducted between 15th February 2023 and 1 April 2023 on these content aggregators and the initial search resulted in 277 articles using the keywords "E. gingivalis", "periodontitis", "E. gingivalis", "periodontal disease", "prevalence", and "incidence", in different combinations. The results showed that 755 patients were infected with E. gingivalis out of a total number of 1729 patients diagnosed with periodontal disease, indicating a global prevalence of 43% in the set of patients analyzed. E. gingivalis was prevalent in 58% of the patients that had gingivitis and in 44% of the patients with periodontitis. Prevalence of E. gingivalis based on gender was 43% in female patients and 47% in male patients. The results indicate that the higher incidence of E. gingivalis in people with periodontal disease compared to healthy people is more than just a sign of the disease; it could also be linked to the severity of the condition and the disease propensity to progress.

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.

Epidemiological investigation of Entamoeba in wild rhesus macaques in China: A novel ribosomal lineage and genetic differentiation of Entamoeba nuttalli.

Wild rhesus macaques are a potential source of zoonotic parasites for humans, and Entamoeba spp. are common intestinal parasites. To investigate the prevalence of Entamoeba in wild rhesus macaques in China and explore the genetic differentiation of the potentially pathogenic species Entamoeba nuttalli, a total of 276 fecal samples from five populations at high altitudes (HAG, 2,800-4,100 m above sea level) and four populations at low altitudes (LAG, 5-1,000 m above sea level) were collected. PCR methods based on the ssrRNA gene were used to detect Entamoeba infection. Genotyping of E. nuttalli was performed based on six tRNA-linked short tandem repeat (STR) loci for further genetic analyses. The results revealed that Entamoeba infection (69.2%) was common in wild rhesus macaques in China, especially in LAG which had a significantly higher prevalence rate than that in HAG (P < 0.001). Three zoonotic species were identified: Entamoeba chattoni (60.9%) was the most prevalent species and distributed in all the populations, followed by Entamoeba coli (33.3%) and Entamoeba nuttalli (17.4%). In addition, a novel Entamoeba ribosomal lineage named RL13 (22.8%) was identified, and phylogenetic analysis revealed a close genetic relationship between RL13 and Entamoeba. hartmanni. Genotyping of E. nuttalli obtained 24 genotypes from five populations and further analysis showed E. nuttalli had a high degree of genetic differentiation (FST > 0.25, Nm < 1) between the host populations. The result of analysis of molecular variance (AMOVA) revealed that observed genetic differences mainly originate from differences among populations (FST = 0.91). Meanwhile, the phylogenetic tree showed that these genotypes of E. nuttalli were clustered according to geographical populations, indicating a significant phylogeographic distribution pattern. Considering the potential pathogenicity of E. nuttalli, attention should be paid to its risk of zoonotic transmission.

No siempre es una enfermedad de Crohn: amebiasis como diagnóstico diferencial de la enfermedad inflamatoria intestinal / It is not always Crohn's disease: Amebiasis as a differential diagnosis of inflammatory bowel disease

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Intestinal parasites in cancer patients in the South of Brazil / Parasitos intestinais em pacientes com câncer do Sul do Brasil

Abstract Intestinal parasitic infections in immunocompromised patients can lead to serious complications when not diagnosed and treated early. This study aimed to investigate the frequency of intestinal parasites in cancer patients undergoing chemotherapy in the South of Brazil. Three fecal samples collected from each patient (73 individuals) were processed by Ritchie and Faust techniques and submitted to specific staining methods for intestinal protozoa. A 61.6% parasite and/or commensal positivity was found. Helminths identified were Ascaris lumbricoides (33.3%), Taenia spp. (6.6%), Strongyloides stercoralis (4.4%) and Trichuris trichiura (2.2%). Among protozoans, Giardia lamblia (26.6%), Cryptosporidium spp. (13.3%) and Cystoisospora belli (4.4%) were identified. The presence of Entamoeba coli, Endolimax nana and Entamoeba hartmanni was also recorded. The results obtained warn of the importance of fecal parasitological diagnosis and the use of specific staining methods for the detection of intestinal parasites in cancer patients. These exams should be regularly requested at the patient's first clinic visit, given the high prevalence found in this study and the possible severity of such conditions for these individuals.

Resumo As parasitoses intestinais em pacientes imunocomprometidos podem levar a graves complicações se não diagnosticadas e tratadas precocemente. Este estudo teve como objetivo investigar a frequência de parasitos intestinais em pacientes oncológicos submetidos ao tratamento quimioterápico. Foram coletadas três amostras de fezes de cada paciente, sendo processadas pelas técnicas de Ritchie e Faust e submetidas à métodos de coloração específicos para protozoários intestinais. Foi encontrada positividade de 61,6% para parasitos e/ou comensais. Os helmintos identificados foram Ascaris lumbricoides (33,3%), Taenia spp. (6,6%), Strongyloides stercoralis (4,4%) e Trichuris trichiura (2,2%). Dentre os protozoários, foram identificados Giardia lamblia (26,6%), Cryptosporidium spp. (13,3%) e Cystoisospora belli (4,4%). Também foi registrada presença de Entamoeba coli, Endolimax nana e Entamoeba hartmanni. Os resultados encontrados alertam para a importância do diagnóstico parasitológico de fezes junto à utilização de colorações específicas para parasitos intestinais em pacientes oncológicos, sendo que os mesmos deveriam ser requeridos como conduta já na primeira consulta clínica destes pacientes, dada à elevada prevalência aqui constatada e a possível severidade que tais moléstias podem acarretar nestes indivíduos.

Detection and differentiation of Entamoeba histolytica and Entamoeba dispar in clinical samples through PCR-denaturing gradient gel electrophoresis

Amebiasis is one of the twenty major causes of disease in Mexico; however, the diagnosis is difficult due to limitations of conventional microscopy-based techniques. In this study, we analyzed stool samples using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) to differentiate between Entamoeba histolytica (pathogenic) and E. dispar (non-pathogenic). The target for the PCR amplification was a small region (228 bp) of the adh112 gene selected to increase the sensitivity of the test. The study involved 62 stool samples that were collected from individuals with complaints of gastrointestinal discomfort. Of the 62 samples, 10 (16.1%) were positive for E. histolytica while 52 (83.9%) were negative. No sample was positive for E. dispar. These results were validated by nested PCR-RFLP (restriction fragment length polymorphism) and suggest that PCR-DGGE is a promising tool to differentiate among Entamoeba infections, contributing to determine the specific treatment for patients infected with E. histolytica, and therefore, avoiding unnecessary treatment of patients infected with the non-pathogenic E. dispar.

Prevalence of ittestinal parasites among food handlers in western Iann / La prevalencia de parasitos intestinales entre los manipuladores de alimentos en el oeste de Iran

Parasitic infection is one of the problems that affect human health, especially in developing countries. In this study, all of the fast food shops, restaurants, and roast meat outlets of Khorramabad (Western Iran) and all the staff employed by them, some 210 people, were selected through a census and their stools were examined for the presence of parasites. The parasitological tests of direct wet-mount, Lugol's iodine staining, formaldehyde-ether sedimentation and Trichrome staining techniques were performed on the samples. The data was analyzed with a chi-square test and logistic regression was selected as the analytical model. The results showed 19 (9%) stool specimens were positive for different intestinal parasites. These intestinal parasites included Giardia lamblia 2.9%, Entamoeba coli 4.3%, Blastocystis sp. 1.4%, and Hymenolepis nana 0.5%. There was a significant difference between the presence of a valid health card, awareness of transmission of intestinal parasites, participation in training courses in environmental health with intestinal parasites (p < 0.05). No statistically significant difference was found between the rate of literacy and gender among patients infected with intestinal parasites (p > 0.05). To control parasitic infection in food handlers, several strategies are recommended such as stool examinations every three months, public education, application of health regulations, controlling the validity of health cards and training on parasitic infection transmission. In this regard, the findings of the present study can be used as a basis to develop preventive programs targeting food handlers because the spread of disease via them is a common problem worldwide.

Infección parasitaria es uno de los problemas de salud humana, especialmente en los países en desarrollo. En este estudio, todas las tiendas de comida rápida, restaurantes, y tiendas de carne asada en Khorramabad (oeste de Irán) y todo el personal que trabaja en ellos, incluyendo 210 personas fueron seleccionadas a través de los censos y las heces fueron examinadas para detectar la presencia de parásitos. La prueba parasitológica directa de mojado de montaje, la tinción de Lugol's yodo, sedimentación formaldehído-éter y tricrómicas técnicas de tinción se realizaron sobre las muestras. Los datos fueron analizados con la prueba de chi-cuadrado y regresión logística seleccionado como el modelo analítico. Los resultados mostraron 19 (9%) muestras de heces fueron positivos para diferentes parásitos intestinales. Los parásitos intestinales incluyen Giardia lamblia 2.9%, Entamoeba coli 4.3%, Blastocystis sp. 1.4%, Hymenolepis nana 0.5%. Hubo diferencia significativa entre la presencia de la tarjeta sanitaria válida, el conocimiento de la transmisión de los parásitos intestinales, la participación en cursos de formación en materia de salud ambiental con parásitos intestinales (p < 0.05). No hubo diferencia estadísticamente significativa entre la tasa de alfabetización y el sexo entre los pacientes infectados con parásitos intestinales (p > 0.05). Para controlar la infección parasitaria en los manipuladores de alimentos se recomiendan varias estrategias, tales como examen de heces cada tres meses, la educación pública, se aplican las normas sanitarias, el control de validez de la tarjeta sanitaria y la transmisión formación infección parasitaria. En este sentido, los resultados del presente estudio se pueden utilizar como una base para desarrollar programas de prevención dirigidos a los manipuladores de alimentos debido a la propagación de enfermedades a través de ellos es un problema común en todo el mundo.

Laboratory diagnosis of amebiasis in a sample of students from southeastern Brazil and a comparison of microscopy with enzyme-linked immunosorbent assay for screening of infections with Entamoeba sp.

Introduction: Epidemiological studies on amebiasis have been reassessed since Entamoeba histolytica and E. dispar were first recognized as distinct species. Because the morphological similarity of these species renders microscopic diagnosis unreliable, additional tools are required to discriminate between Entamoeba species. The objectives of our study were to compare microscopy with ELISA kit (IVD®) results, to diagnose E. histolytica infection, and to determine the prevalence of amebiasis in a sample of students from southeastern Brazil. Methods: In this study, diagnosis was based on microscopy due to its capacity for revealing potential cysts/trophozoites and on two commercial kits for antigen detection in stool samples. Results: For 1,403 samples collected from students aged 6 to 14 years who were living in Divinópolis, Minas Gerais, Brazil, microscopy underestimated the number of individuals infected with E. histolytica/E. dispar (5.7% prevalence) compared with the ELISA kit (IVD®)-based diagnoses (15.7% for E. histolytica/E. dispar). A comparison of the ELISA (IVD®) and light microscopy results returned a 20% sensitivity, 97% specificity, low positive predictive value, and high negative predictive value for microscopy. An ELISA kit (TechLab®) that was specific for E. histolytica detected a 3.1% (43/1403) prevalence for E. histolytica infection. Conclusions: The ELISA kit (IVD®) can be used as an alternative screening tool. The high prevalence of E. histolytica infection detected in this study warrants the implementation of actions directed toward health promotion and preventive measures. .

Diferenciación del complejo Entamoeba histolytica/Entamoeba dispar mediante Gal/GalNAc-lectina y PCR en aislamientos colombianos / Differentiation of entamoeba histolytica from entamoeba dispar using Gal/GalNAc-lectin and polymerase chain reaction

Background: Entamoeba histolytica and Entamoeba dispar are morphologically identical. However, the former is highly pathogenic and the latter is not. Aim: To differentiate Entamoeba histolytica from Entamoeba dispar through ELISA and PCR techniques in Colombian isolates from feces. Material and Methods: Descriptive study of Colombian fecal samples from 53 males and 47 women, that were positive for the complex E. histolytica/E. dispar on light microscopy. Positive samples were cultured on Robinson medium to isolate trophozoites. The presence of specific Gal/ GalNAc-lectin was determined by ELISA and polymerase chain reaction in genomic DNA, using the combination of three nucleotides that recognize a variable region of 16S small subunit ribosomal RNA, generating a 166 base pair (bp) product for E. histolytica and 752 pb product for E. dispar. Results: After verification, only eight of the 100 samples were positive for the complex E. histolytica/E. dispar and were cultivated. Isolates were obtained in six cultures, one corresponded to E. histolytica and six to E. dispar. Conclusions: The presence of E. histolytica/E. dispar complex was largely overestimated with light microscopy. In the few samples where isolates were obtained, the technique described differentiated between both strains.

Environmental analyses of the parasitic profile found in the sandy soil from the Santos municipality beaches, SP, Brazil / Análise ambiental do perfil de estruturas parasitárias encontradas no solo arenoso das praias do município de Santos, SP, Brasil

The environmental contamination by geohelminths represents a world public health problem and has been well documented by several authors. However, few papers describe the presence of such contamination in saline soils of coastal beaches. A study was performed on the beaches of the municipality of Santos in the period between May 2004 to April 2005 with the aim of determining the degree of contamination, and the correlation between contamination level and seasonal conditions and characteristics of the environment. Of the 2,520 samples analyzed, 18.2 percent (458) were contaminated, 32.3 percent (148) of which were localized in children's recreational areas (playgrounds). The parasite profile found in the analyzed samples indicated the presence of several zoonotic parasites: Ancylostoma larvae (82.5 percent), Toxocara sp. eggs (59.4 percent), Ancylostomidae-like eggs (37.1 percent), coccid oocysts (13.5 percent), Trichostrongylus sp. eggs and larvae, Ascaris lumbricoides eggs, (11.6 percent), Entamoeba sp. cysts (10.0 percent), Strongyloides sp. (4.8 percent), several free nematoids and some non-identified parasitic structures (3.3 percent). It was established that the highest frequency of parasitic structures occurred in the months between May and October 2004, and from February to March 2005. An increase in the diversity of parasitic forms was documented in the months between February to December 2004 and from January to April 2005, these periods having the highest rainfall.

A contaminação ambiental por geohelmintos representa um problema mundial de saúde pública e tem sido bem documentada por diversos autores. No entanto, poucos trabalhos descrevem a presença de contaminação em solos salinos de praias litorâneas. Este estudo foi realizado nas praias do município de Santos no período entre maio de 2004 a abril de 2005 com o objetivo de determinar o grau de contaminação, e possíveis correlações entre sazonalidade e características ambientais. Das 2.520 amostras analisadas, 18,2 por cento (458) estavam contaminadas, 32,3 por cento (148) das quais foram localizadas em areas de lazer das crianças(playgrounds). O perfil parasitário encontrado nas amostras analisadas indicaram a presença de vários parasitos com potencial zoonótico: larvas de Ancylostoma (82,5 por cento), ovos de Toxocara sp (59,4 por cento), ovos semelhantes aos de Ancilostomídeos (37,1 por cento), oocistos de coccídeos (13,5 por cento), ovos de Trichostrongylus sp., ovos de Ascaris lumbricoides, (11,6 por cento), cistos de Entamoeba sp. (10,0 por cento), Strongyloides sp. (4,8 por cento), vários nematóides de vida livre e algumas estruturas parasitárias não identificadas que podem corresponder a um parasita (3,3 por cento). Foi estabelecido que a maior frequência de estruturas parasitárias ocorreu nos meses entre maio e outubro de 2004, e de fevereiro a março de 2005. Um aumento na diversidade de formas parasitárias foi documentado nos meses entre fevereiro a dezembro de 2004 e de janeiro a abril de 2005, esses períodos com a maior pluviosidade.

Validation and utilization of PCR for differential diagnosis and prevalence determination of Entamoeba histolytica/Entamoeba dispar in Salvador City, Brazil

Amoebiasis is an infection caused by Entamoeba histolytica and is a potential health risk in countries in which health barriers are inappropriate. Since the discovery of Entamoeba dispar, the prevalence of amoebiasis has been modified. OBJECTIVE: This study has standardized the PCR technique applied for the diagnosis of different species of the E. histolytica/E. dispar complex and has evaluated the prevalence of infection among patients attending private and public clinical laboratories in Salvador City, Bahia State, Brazil. RESULTS: Analysis of 52,704 stool samples by microscopic examination demonstrated that 1,788 (3.4 percent) were positive for the E. histolytica/E. dispar complex and infection occurred more often in samples originated from public clinical laboratories (5.0 percent) than those that came from private laboratories (3.2 percent). PCR performed in approximately 15 percent (262) E. histolytica/E. dispar complex positive samples, randomly chosen, amplified 227 samples (86.6 percent), all of them positive for E. dispar. The non-amplified 35 samples (13.4 percent) were also negative for E. histolytica-specific galactose adhesin. Moreover, to exclude a probable infection caused by E. hartmanni, morphometric analysis demonstrated that non-amplified samples had cyst sizes comparable to E. histolytica/E. dispar (>10 µm). CONCLUSION: The absence of amplification of these samples indicates the presence of PCR inhibitors in the stool samples or the presence of DNA from Entamoeba species other than E. dispar, E. histolytica or E. hartmanni.

Amebas intestinales no patógenas: una visión clinicoanalítica / Non-pathogenic intestinal amoebae: a clinical-analytical overview

El ser humano puede ser parasitado por diferentes especies de amebas intestinales. Entamoeba histolytica es la única de reconocido poder patógeno, mientras que las restantes, E. dispar, E. moshkovskii, E. hartmanni, E. coli, E. polecki, Endolimax nana y Iodamoeba buetschlii, se consideran no patógenas. El objetivo de esta revisión es sintetizar las características morfológicas fundamentales de los estadios de trofozoíto y de quiste de cada una de ellas como base primordial para llevar a cabo un diagnóstico microscópico preciso. La dificultad que conlleva la diferenciación morfológica entre las especies englobadas en el denominado “complejo Entamoeba” obliga al uso de métodos diagnósticos inmunológicos y moleculares. También se lleva a cabo una síntesis de los aspectos epidemiológicos e incluso terapéuticos y profilácticos básicos de este grupo de amebas no patógenas. Todo ello resulta relevante porque estas amebas se encuentran presentes habitualmente en las analíticas coproparasitológicas humanas y deben ser diferenciadas de la especie patógena, E. histolytica. Además, se pueden utilizar como adecuados marcadores biológicos del grado de saneamiento ambiental y de las medidas higienicosanitarias de la población (AU)

Human beings can be parasitized by various species of intestinal amoebae. Entamoeba histolytica is the onlyintestinal amoeba recognized to be pathogenic, while other amoeba species, E. dispar, E. moshkovskii, E.hartmanni, E. coli, E. polecki, Endolimax nana and Iodamoeba buetschlii are considered to be non-pathogenic.The aim of this review is to synthesize the main morphological characteristics of the trophozoite and cyststages of each amoeba as the basis for precise microscopical diagnosis. The difficulty of morphological differentiation among species included in the so-called “Entamoeba complex” entails the use of immunological and molecular diagnoses. In addition, a summary of basic epidemiological, therapeutic and prophylactic aspects of these non-pathogenic amoebae is provided. All of these aspects are crucial since these amoebae are usually found to be present in human coproparasitological analyses and must be differentiated from the pathogenic species E. histolytica. Furthermore, they can be used as suitable biological tags of the hygienic state of the environment and the health and hygiene measures of the population (AU)

Detección y diferenciación de Entamoeba histolytica y Entamoeba dispar mediante reacción en cadena de la polimerasa en individuos de una comunidad del Estado Zulia, Venezuela / Detection and differentiation of Entamoeba histolytica and Entamoeba dispar by polymerase chain reaction in a community in Zulia State, Venezuela

Differential identification of Entamoeba histolytica and Entamoeba dispar is essential for both appropriate patient treatment and epidemiological purposes. To determine the prevalence of these amoeba infections in Santa Rosa de Agua (Maracaibo, Zulia State, Venezuela), a PCR assay using specific primers for each species was standardized and applied. 204 stool samples were analyzed through direct microscopic examination with SSF (0.85 percent) and lugol, formol-ether concentration, and PCR. Under direct microscopy, 42 individuals (20.58 percent) presented the E. histolytica/E. dispar complex. Meanwhile PCR showed 47 positive cases for these amoebas: 22 E. histolytica (10.78 percent), 16 E. dispar (7.84 percent), and 9 (4.41 percent) mixed infections. There was no significant difference in the presence of E. histolytica and/or E. dispar according to either gender or age. There were no cases of these amoebas in children under 2 years of age. Observed frequency of E. histolytica (31/204) shows the endemic nature of amoeba infection in this community.

La identificación diferencial de Entamoeba histolytica y Entamoeba dispar es esencial para un tratamiento adecuado del paciente y con fines epidemiológicos. Para determinar la prevalencia de E. histolytica y E. dispar se estandarizó y aplicó un ensayo de PCR, utilizando oligonucleótidos específicos para cada especie. 204 muestras de heces de individuos de la comunidad de Santa Rosa de Agua (Municipio Maracaibo, Estado Zulia, Venezuela), fueron analizadas a través del examen directo con SSF (0,85 por ciento) y lugol, concentrado de formol-éter y PCR. Al examen microscópico, 42 individuos (20,58 por ciento) presentaron formas evolutivas del complejo E. histolytica/E. dispar; mientras que la técnica de PCR evidenció un total de 47 casos positivos a estas amibas; de los cuales 22 eran portadores de E. histolytica (10,78 por ciento), 16 (7,84 por ciento) de E. dispar y 9 (4,41 por ciento) presentaron infección mixta. No hubo diferencia significativa al relacionar las variables sexo y presencia de E. histolytica y/o E. dispar, ni con los grupos etarios. No existieron casos de estas amibas, en los menores de 2 años. La frecuencia observada de E. histolytica (31/204), demuestra el carácter endémico de la amibiasis en esta comunidad.