Enterocytozoon bieneusi and Encephalitozoon intestinalis (microsporidia) in HIV-positive patients in central Spain.

Microsporidia are fungi-related eukaryotic intracellular parasites that opportunistically infect immunocompromised individuals such as those infected by the human immunodeficiency virus (HIV). Among them, Enterocytozoon bieneusi and Encephalitozoon spp. are the most clinically relevant species. We investigated the occurrence and genetic diversity of microsporidial and protist infections in mostly immunocompetent HIV-positive patients in Madrid, Spain. A structured questionnaire was used to retrieve data on factors potentially associated with an increased risk of infection, including sexual attitudes and sex-risk behaviour. Faecal samples (n = 96) from 81 HIV-positive patients were collected and analysed by molecular (PCR and Sanger sequencing) methods. Two microsporidial pathogens were detected: Ent. bieneusi (2.5%, 95% CI: 0.3-8.6) and Enc.intestinalis (4.9%, 95% CI: 1.4-12.2). The two Ent. bieneusi isolates were identified as zoonotic genotype A. Among protists, Entamoeba dispar was the species most prevalently found (33.3%, 95% CI: 23.2-44.7), followed by Blastocystis spp. (19.8%, 95% CI: 11.7-30.1), Giardia duodenalis (13.6%, 95% CI: 7.0-23.0), and Cryptosporidium spp. and Entamoeba histolytica (2.5%, 95% CI: 0.3-8.6 each). Cyclospora cayetanensis and Cystoisospora belli were not detected. Subtypes ST1 (70.6%, 12/17) and ST3 (29.4%, 5/17) were identified within Blastocystis sp., sub-assemblages AII and BIII (50%, 1/2 each) within G. duodenalis, and Cry. parvum and canine-adapted Cry. canis (50%, 1/2 each) within Cryptosporidium spp. Microsporidial and protist parasites were frequent in well-controlled, mostly immunocompetent HIV-positive patients and should be included in diagnostic algorithms when diarrhoea is present.

Opportunistic microsporidial and protist intestinal infections were relatively common in well-controlled HIV-positive patients in Madrid, Spain. These agents should be suspected and appropriately diagnosed in HIV-positive patients presenting with diarrhoea regardless of their immunological status.

Intestinal parasite infections associated with sociodemographic and seasonal factors in the Western Amazon.

Intestinal parasites are a constant public health problem in the Amazon region, with a high prevalence of cases related to poor sanitary conditions. We investigated the sociodemographic and seasonal factors associated with human intestinal parasite infections in an area of the Western Amazon, Brazil, from September 2017 to August 2019. Data were collected using a database available at the Diagnostic Support Centre (Centro de Apoio ao Diagnóstico, CAD) of the Municipality of Rio Branco, on positive diagnoses for intestinal parasites. Among the 53,200 samples analysed, 18.3% (n = 9712) were positive. Of these, 96.4% (n = 9363) and 3.6% (n = 349) were protozoan and helminthic infections, respectively. Males showed higher odds ratio (OR) for Enterobius vermicularis infection (OR: 2.3) and giardiasis (OR: 1.9) and lower OR for Endolimax nana (OR: 0.9) and Entamoeba coli (OR: 0.9) infections. Individuals aged ≥ 15 presented higher OR for Strongyloides stercoralis (OR: 3.4), hookworms (OR: 2.3), and almost all protozoan infections than younger individuals. In the dry season, the OR for hookworms (OR: 1.5), Iodamoeba butschlii (OR: 1.4), and Endolimax nana (OR: 1.3) infections was higher than that in the rainy season, including a high chance of polyparasitism (OR: 1.6). We concluded that there was a significant difference between the different types of intestinal parasites, particularly protozoa, with high OR in the dry season and for certain groups.

Prevalence and Risk Factors for Intestinal Protozoan Infections in Children with Cancer in Taif, Western Saudi Arabia.

BACKGROUND: Cancer is a category of diseases that cause an individual's immune system to become suppressed. In a case-control study, the current study aims to detect the frequency of intestinal parasites and related risk factors in children with cancer. METHODS: Stool samples were collected from 178 children with cancers (cases) and 150 cancer-free children (controls) who sought treatment for diarrheal episodes at nearby hospitals. Samples were processed by direct smear examination, concentration technique, permanent staining by Lugol's iodine, modified Ziehl-Neelsen, modified trichrome, and chromotrope 2R stains. RESULTS: The overall prevalence of intestinal parasites was 7.3% (24/328), with non-statistically significant differences between cases (7.8%; 14/178) and controls (6.6%; 10/150). Children with leukemia had a higher infection rate (9%; 9/100) than children with lymphoma (6.9%; 3/43) or solid tumors (5.7%; 2/35). Blastocystis sp. (3.3%) was the most common intestinal parasite found in cases, followed by Cryptosporidium sp. (2.2%), Giardia lamblia (1.6%), and Microsporidia sp. (0.5%). For all parasites, no statistical difference was found between the two groups. (p > 0.05). Male gender, young age, non-bottled water use, travel to parasite-endemic areas, living in an urban area, and infrequent hand washing were all associated with intestinal parasitosis, with non-statistical significance observed between the two groups. In children with cancer, intestinal parasites were found to be significantly associated with chronic (p = 0.04) and severe (p = 0.03) diarrhea. CONCLUSIONS: Children with cancer, particularly those with hematological cancers, should be screened for intestinal parasites on a regular basis and treated for their overall health.

Prevalence of Pathogens in Young Children Presenting to Hospital with Diarrhea from Lambaréné, Gabon.

Diarrheal disease is the second most frequent cause of mortality in children younger than 5 years worldwide, causing more than half a million deaths each year. Our knowledge of the epidemiology of potentially pathogenic agents found in children suffering from diarrhea in sub-Saharan African countries is still patchy, and thereby hinders implementation of effective preventative interventions. The lack of cheap, easy-to-use diagnostic tools leads to mostly symptomatic and empirical case management. An observational study with a total of 241 participants was conducted from February 2017 to August 2018 among children younger than 5 years with diarrhea in Lambaréné, Gabon. Clinical and demographic data were recorded, and a stool sample was collected. The samples were examined using a commercial rapid immunoassay to detect Rotavirus/adenovirus, conventional bacterial culture for Salmonella spp., and multiplex real-time PCR for Cryptosporidium spp., Giardia lamblia, Cyclospora cayetanensis, enterotoxigenic Escherichia coli (ETEC), and enteroinvasive Escherichia coli (EIEC)/Shigella. At least one infectious agent was present in 121 of 241 (50%) samples. The most frequently isolated pathogens were EIEC/Shigella and ETEC (54/179; 30.2% and 44/179; 24.6%, respectively), followed by G. lamblia (33/241; 13.7%), Cryptosporidium spp. (31/241; 12.9%), and Rotavirus (23/241; 9.5%). Coinfection with multiple pathogens was observed in 33% (40/121) of the positive cases with EIEC/Shigella, ETEC, and Cryptosporidium spp. most frequently identified. Our results provide new insight into the possible causes of diarrheal disease in the Moyen-Ogooué region of Gabon and motivate further research on possible modes of infection and targeted preventive measures.

Iron in parasitic protists - from uptake to storage and where we can interfere.

It is well known that iron is a crucial micronutrient for all living organisms. Due to its chemical properties, iron is an irreplaceable cofactor of many essential enzymes but is also potentially toxic when present in excess. The acquisition of iron from the environment can be challenging for organisms, especially for parasitic protists that rely solely on the host for available nutrients. One of the host defense mechanisms is to starve parasites by detaining the crucial iron in a form unreachable for pathogens. In this review, we summarize current information about iron homeostasis-related pathways of important human parasites, such as Plasmodium, trypanosomes, Leishmania, pathogenic amoebas and Trichomonas. We focus on the parasites' strategies of iron acquisition, storage/detoxification, trafficking, and iron-regulated protein expression and address the questions of iron-influenced virulence and anti-parasitic chemotherapeutics targeted to iron metabolism. Finally, we outline the potential of understudied and somewhat neglected iron chelating agents as safe chemotherapeutics against protozoan parasites.

Prevalencia de parásitos intestinales en muestras de pacientes atendidos en el Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Argentina, 2018-2019 / Prevalence of intestinal parasites in samples of patients attending the Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Argentina, 2018-2019 / Prevalência de parasitas intestinais em amostras de pacientes atendidos no Hospital de Pediatría "Prof. Dr. Juan P. Garrahan", Argentina, 2018-2019

Resumen Se evaluaron retrospectivamente los resultados obtenidos de estudios parasitológicos en muestras de heces y escobillados anales remitidos al Laboratorio de Parasitología y Gastroenterología del Hospital de Pediatría "Prof. Dr. Juan P. Garrahan" de la Ciudad de Buenos Aires, Argentina. El objetivo del trabajo fue conocer la prevalencia de los parásitos intestinales observados en las muestras remitidas a este hospital y su distribución en rangos etarios. En el período comprendido entre mayo de 2018 y abril de 2019 se analizó un total de 4713 muestras pertenecientes a 3311 pacientes, que arrojó un resultado total de 29% de positivos (1371/4713). De los exámenes coproparasitológicos el 30% fueron positivos (1193/4025) y se hallaron huevos de Enterobius vermicularis en el 26% (178/688) de los escobillados anales. En las muestras seriadas de heces se obtuvo un 37% de positividad mientras que en muestras únicas un 21%. En la totalidad de muestras fecales, los enteroparásitos más prevalentes fueron Blastocystis spp. en un 14% (579/4025), Giardia duodenalis 11% (456/4025) y Dientamoeba fragilis 7% (291/4025). Los resultados demostraron diferencias significativas con mayor prevalencia de parásitos intestinales en pacientes en edad escolar comprendidos entre los 6 y 10 años, en relación a los de edad preescolar. En las muestras fecales analizadas se evidenció un predominio de parasitismo de protozoos sobre helmintos, por lo que se debería considerar reforzar el diagnóstico de laboratorio de esas especies mediante técnicas, como coloraciones, que posibiliten su hallazgo y confirmación.

Abstract The results obtained of the coproparasitological studies and anal swab submitted to the laboratory of the Parasitology Section of the Hospital de Pediatría "Prof. Dr. Juan P. Garrahan" of the Buenos Aires City, Argentina, were retrospectively evaluated The aim of this study was to determine the prevalence of intestinal parasites found on the submitted samples and to evaluate their frequency according to the age of the patients. Within the period between May 2018 and April 2019, a total of 4713 samples corresponding to 3311 patients were analyzed and intestinal parasites were present in 29% (1371/4713). In 30% of coproparasitological studies parasite estructures were found (1193/4025) and 26% of anal swab samples were positive for the presence of Enterobius vermicularis eggs (178/688). In serial fecal samples, 37% positive results were obtained, while in single samples, 21%. The most prevalent enteroparasites calculated from the total fecal samples were: Blastocystis spp. with 14% (579/4025), followed by Giardia duodenalis 11% (456/4025) and Dientamoeba fragilis 7% (291/4025). The incidence of intestinal parasites was higher in the group of patients between 6 and 10 years, and the existence of significant differences between proportions of parasitized patients in preschool and school infants, was observed. In the faecal samples analyzed, a greater prevalence of parasitism caused by protozoa than by helminths was evidenced, for which reason it should be considered, reinforcing the laboratory diagnosis using techniques such as stains that allow its finding and confirmation.

Resumo Os resultados obtidos de estudos parasitológicos em amostras fecais e esfregaços anais enviados ao Laboratório de Parasitologia e Gastroenterologia do Hospital de Pediatría "Prof. Dr. Juan P. Garrahan" da Cidade de Buenos Aires, Argentina, foram avaliados retrospectivamente. O objetivo do estudo foi avaliar a prevalência dos parasitas intestinais observados nas amostras enviadas a este hospital e sua distribuição por faixas etárias. Durante o período compreendido entre maio de 2018 a abril de 2019 foram analisadas 4713 amostras, correspondentes a 3311 pacientes, o que deu um resultado total de 29% de positivos (1371/4713). 30% dos exames coproparasitológicos foram positivos (1193/4025) e foram encontrados ovos de Enterobius vermicularis em 26% (178/688) dos esfregaços anais. Nas amostras seriadas fecais foram obtidos 37% de resultados positivos, enquanto que em amostras únicas, 21%. Os enteroparasitas mais prevalentes na totalidade das amostras fecais foram Blastocystis spp. em 14% (579/4025), Giardia duodenalis 11% (456/4025) e Dientamoeba fragilis 7% (291/4025). Os resultados demonstraram diferenças significativas com maior prevalência de parasitas intestinais em pacientes em idade escolar da faixa etária entre 6 e 10 anos, em relação aos da pré-escola. Nas amostras fecais analisadas, evidenciou-se um predomínio de parasitismo por protozoários por sobre helmintos, pelo qual deve ser considerado o reforço do diagnóstico laboratorial dessas espécies por meio de técnicas, como colorações que permitam a sua localização e confirmação.

Molecular prevalence of intestinal parasites infections in children with diarrhea in Franceville, Southeast of Gabon.

BACKGROUND: Pediatric diarrhea caused by a range of pathogens, including intestinal parasites, is one of main causes of death among children under 5 years of age. The distribution of these parasitic infections overlaps in many environmental, socioeconomic and epidemiological settings. Their distribution and prevalence varies from region to region. In the current study, we assess the prevalence of intestinal parasites among pediatric patients with syndromic diarrheal disease living in Franceville, Gabon. METHODS: A cross-sectional study conducted in the Amissa Bongo Regional Hospital and Chinese-Gabonese Friendship Hospital in Franceville, between November 2016 and August 2017, enrolled a total of 100 diarrheic children between 0 and 180 months of age. Parasite detection in stool samples was performed using molecular diagnostic by PCR. Difference in means were tested by Student's t test and ANOVA while principal component analysis was used to determine the correlation between parasite distributions and age groups. RESULTS: The overall prevalence of intestinal parasite infection was 61% (61/100). Hymenolepis sp and Cryptosporidium hominis/parvum were the most common parasites (31 and 19%, respectively), followed by Encephalitozoon intestinalis (15%), Trichuris trichiura (4%), Dientamoeba fragilis (4%), and Enterocytozoon bieneusi (2%). The polyparasitism rate was 19.7%, with 83.3% double and 16.7% triple infections. Protozoan infections (66.7%) were more prevalent than helminths infections (33.3%). Seasonal association of the circulation of intestinal parasite was statistically significant (p = 0.03). Correlations between different parasites was also observed. CONCLUSION: The prevalence of intestinal parasitic infections is highest in diarrheic pediatric children. The prevalence of parasitic infections indicates that protozoa and helminths are the most common parasites in the Franceville environment. This study reinforces the importance of routine examination of diarrheic stool samples for the diagnostic of intestinal parasites. Further analyses are required to better understand the local epidemiology and risk factors associated with the transmission of intestinal parasites in Franceville, Gabon. KEYSWORDS: diarrhea, children, intestinal parasitic infections, molecular diagnostic, Franceville, Gabon.

Alta prevalência de Balantidium coli em crianças de uma Escola Municipal de Moreira Sales - Pr / High prevalence of balantidium coli in children of a Municipal School in Moreira Sales - Pr

As doenças causadas por parasitos intestinais estão entre os mais frequentes agravos do mundo, pois é um problema de saúde pública que atinge a maioria da população. O presente estudo teve como objetivo verificar a prevalência de parasitos em crianças de 4 a 6 anos de uma escola municipal de Moreira Sales, PR. A pesquisa foi composta por inquérito parasitológico e epidemiológico em crianças matriculadas em uma escola municipal em julho de 2017. O critério para inclusão no estudo foi: coletar a amostra de fezes, responder o questionário socioepidemiológico e ter o Termo de Consentimento Livre e Esclarecido (TCLE) assinado pelos pais e/ou responsáveis. Participaram do estudo 42 crianças com idades entre 4 e 6 anos, das quais 66,7% eram meninas. Dos participantes, dez crianças (23,8%) apresentaram infecção por Balantidium coli, sendo que destas, duas apresentaram infecção mista por Entamoeba coli. Foi observado que a maioria dos infectados possuíam animais de estimação (60%), roíam unhas (60%), consumiam hortaliças (80%) e todas as crianças brincavam na terra, sendo esses alguns fatores de risco para a infecção. Diante dos resultados apresentados, é possível perceber que existem vários fatores que podem estar associados à infecção por Balantidium coli, sendo os principais: falta de saneamento básico e os hábitos de higiene inadequado. Portanto, fatores importantes para se promover a conscientização e ação profilática da população, com o intuito de minimizar as parasitoses, principalmente nas crianças.

Diseases caused by intestinal parasites are among the most frequent ones in the world, since it is a public health issue affecting most of the population. The purpose of this study was to verify the prevalence of parasites in children aged 4 to 6 years at a school in the municipality of Moreira Sales, in the state of Paraná, Brazil. The study was comprised by the parasitological and epidemiological investigation in children enrolled in a school in the city in July 2017. The criteria for inclusion in the study was to collect the stool sample, answer the socio-epidemiological questionnaire and sign a Free and Clarified Consent Form. A total of 42 children took part in this study, with ages ranging between 4 and 6 years, of which 66.7% were female. From the participants, ten children (23.8%) presented infection by Balantidium coli, and among which, two of them presented mixed infection by Entamoeba coli. It was observed that most of the infected children had pets (60%), bit their nails (60%), consumed vegetables (80%) and all children played on dirt, which are some of the risk factors for infection. Considering the results, it is possible to observe that there are several factors that can be associated to infection by Balantidium coli, among which: basic sanitation and hygiene habits. Therefore, raising awareness and presenting prophylactic action to the population is essential in order to minimize intestinal parasitosis, especially in children.

Cryptic species in the parasitic Amoebophrya species complex revealed by a polyphasic approach.

As critical primary producers and recyclers of organic matter, the diversity of marine protists has been extensively explored by high-throughput barcode sequencing. However, classification of short metabarcoding sequences into traditional taxonomic units is not trivial, especially for lineages mainly known by their genetic fingerprints. This is the case for the widespread Amoebophrya ceratii species complex, parasites of their dinoflagellate congeners. We used genetic and phenotypic characters, applied to 119 Amoebophrya individuals sampled from the same geographic area, to construct practical guidelines for species delineation that could be applied in DNA/RNA based diversity analyses. Based on the internal transcribed spacer (ITS) regions, ITS2 compensatory base changes (CBC) and genome k-mer comparisons, we unambiguously defined eight cryptic species among closely related ribotypes that differed by less than 97% sequence identity in their SSU rDNA. We then followed the genetic signatures of these parasitic species during a three-year survey of Alexandrium minutum blooms. We showed that these cryptic Amoebophrya species co-occurred and shared the same ecological niche. We also observed a maximal ecological fitness for parasites having narrow to intermediate host ranges, reflecting a high cost for infecting a broader host range. This study suggests that a complete taxonomic revision of these parasitic dinoflagellates is long overdue to understand their diversity and ecological role in the marine plankton.

Melaleuca alternifolia (tea tree) oil and its monoterpene constituents in treating protozoan and helminthic infections.

Australian tea tree (Melaleuca alternifolia) oil (TTO) and its monoterpene constituents such as terpinen-4-ol (T4O), 1,8-cineole, limonene, p-cymene, and α-terpinene have been shown to be effective in controlling a wide range of parasitic infections. The anti-parasitic effects of these compounds are mainly due to their anti-histamine and anti-acetylcholinesterase activities as well as their ability to modulate host inflammatory responses. This review attempts to summarize recent advances in the uses of TTO and its 15 major monoterpene constituents in treating parasitic infections in both humans and animals. Activities against parasitic protozoans (Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Acanthamoeba castellanii, Trichomonas vaginalis, Eimeria, and Ichthyophthirius multifiliis), nematodes (Haemonchus contortus and Anisakis simplex), cestode (Echinococcus ortleppi), and monogeneans (Gasterosteus spp. and Dactylogyrus minutus) have been reported, showing good potentials in treating parasitic infections. Further studies are necessary for developing anti-parasite therapies using TTO or its monoterpenes constituents.

Hepatozoon sp. gamonts as an accidental finding in synovial liquid from an injured maned wolf (Chrysocyon brachyurus) in southeastern Brazil / Gamontes de Hepatozoon sp. como achado acidental em líquido sinovial de lobo guará (Chrysocyon brachyurus) no sudeste do Brasil

Abstract A free-living, adult male maned wolf (Chrysocyon brachyurus) was referred to the Governador "Laudo Natel" - FCAV/Unesp veterinary hospital after being found with skin lesions and a fracture on the right pelvic limb, which had to be amputated due to compromised integrity. Around 20 days later, bilateral accentuated swollen on humerus-radius-ulna articulation was observed. The synovial liquid was drained and sent to the laboratory for synovial cytology with Rosenfeld staining that revealed predominantly degenerated neutrophils with karyolytic chromatin associated with intracellular inclusions suggestive of Hepatozoon sp. gametocytes. Blood and synovial liquid samples were submitted to molecular analysis, aiming to amplify the Hepatozoon spp. 18S rRNA gene fragment. Despite the positioning of the found Hepatozoon sequence together with Hepatozoon canis previously detected in domestic carnivores, the BLAST analysis showed only 98% identity with H. canis. To the best of the authors' knowledge, this is the first time a Hepatozoon was detected in the synovial liquid by clinical pathology and molecular analyses.

Resumo Um lobo guará (Chrysocyon brachyurus) adulto, macho, de vida livre foi encaminhado para atendimento no hospital veterinário Governador "Laudo Natel" - FCAV/Unesp após ser encontrado com lesões de pele e fratura em membro pélvico direito, sendo amputado devido a comprometimento da integridade do membro. Aproximadamente 20 dias após a chegada ao hospital, foi notado acentuado aumento de volume bilateral em região de articulação úmero-rádio-ulnar. O líquido sinovial foi drenado e enviado para análise citológica com coloração de Rosenfeld, revelando a presença de neutrófilos degenerados com cromatina cariolítica associados a inclusões intracelulares sugestivas de gametócitos de Hepatozoon sp. Amostras de sangue e líquido sinovial foram submetidas a análises moleculares visando amplificar um fragmento do gene 18S rRNA de Hepatozoon spp. Apesar da sequência de Hepatozoon detectada se posicionar filogeneticamente no mesmo clado que H. canis previamente detectado em carnívoros domésticos, o resultado da análise do BLAST mostrou somente 98% de identidade com H. canis. De acordo com o conhecimento dos autores, esta é a primeira vez que Hepatozoon foi detectado no líquido sinovial por meio de patologia clínica e análises moleculares.

Small Molecule Inhibitors Targeting the Heat Shock Protein System of Human Obligate Protozoan Parasites.

Obligate protozoan parasites of the kinetoplastids and apicomplexa infect human cells to complete their life cycles. Some of the members of these groups of parasites develop in at least two systems, the human host and the insect vector. Survival under the varied physiological conditions associated with the human host and in the arthropod vectors requires the parasites to modulate their metabolic complement in order to meet the prevailing conditions. One of the key features of these parasites essential for their survival and host infectivity is timely expression of various proteins. Even more importantly is the need to keep their proteome functional by maintaining its functional capabilities in the wake of physiological changes and host immune responses. For this reason, molecular chaperones (also called heat shock proteins)-whose role is to facilitate proteostasis-play an important role in the survival of these parasites. Heat shock protein 90 (Hsp90) and Hsp70 are prominent molecular chaperones that are generally induced in response to physiological stress. Both Hsp90 and Hsp70 members are functionally regulated by nucleotides. In addition, Hsp70 and Hsp90 cooperate to facilitate folding of some key proteins implicated in cellular development. In addition, Hsp90 and Hsp70 individually interact with other accessory proteins (co-chaperones) that regulate their functions. The dependency of these proteins on nucleotide for their chaperone function presents an Achille's heel, as inhibitors that mimic ATP are amongst potential therapeutic agents targeting their function in obligate intracellular human parasites. Most of the promising small molecule inhibitors of parasitic heat shock proteins are either antibiotics or anticancer agents, whose repurposing against parasitic infections holds prospects. Both cancer cells and obligate human parasites depend upon a robust protein quality control system to ensure their survival, and hence, both employ a competent heat shock machinery to this end. Furthermore, some inhibitors that target chaperone and co-chaperone networks also offer promising prospects as antiparasitic agents. The current review highlights the progress made so far in design and application of small molecule inhibitors against obligate intracellular human parasites of the kinetoplastida and apicomplexan kingdoms.

Host Invasion by Pathogenic Amoebae: Epithelial Disruption by Parasite Proteins.

The epithelium represents the first and most extensive line of defence against pathogens, toxins and pollutant agents in humans. In general, pathogens have developed strategies to overcome this barrier and use it as an entrance to the organism. Entamoeba histolytica, Naegleriafowleri and Acanthamoeba spp. are amoebae mainly responsible for intestinal dysentery, meningoencephalitis and keratitis, respectively. These amoebae cause significant morbidity and mortality rates. Thus, the identification, characterization and validation of molecules participating in host-parasite interactions can provide attractive targets to timely intervene disease progress. In this work, we present a compendium of the parasite adhesins, lectins, proteases, hydrolases, kinases, and others, that participate in key pathogenic events. Special focus is made for the analysis of assorted molecules and mechanisms involved in the interaction of the parasites with epithelial surface receptors, changes in epithelial junctional markers, implications on the barrier function, among others. This review allows the assessment of initial host-pathogen interaction, to correlate it to the potential of parasite invasion.

Intestinal parasitic infections and associated factors in children of three rural schools in Colombia. A cross-sectional study.

Rural children are one of the populations that are most vulnerable to gastrointestinal parasite infections. Such diseases decrease the quality of life and result in growth and cognitive delays in the long term. This cross-sectional study was conducted to determine the frequency of intestinal parasite infections among rural schoolchildren in the municipality of Apulo, Colombia. A total of 97 stool samples from children aged between 5 and 15 years were collected and examined via direct light microscopy. Microscopic examination was repeated with sediments obtained using a fecal parasite concentrator, and the Kato-Katz test was performed. Frequency of intestinal parasite infection was 100%. Endolimax nana (77.35%), Blastocystis sp. (71.1%), Giardia intestinalis (39.1%), Entamoeba coli (25.7%), and the Entamoeba histolytica/dispar/moshkovskii complex (9.2%) were the most prevalent protozoa. Trichuris trichiura was the most prevalent helminth (12.3%), followed by Enterobius vermicularis (6.15%) and Ascaris lumbricoides (5.1%). Among the analyzed associated factors, consumption of untreated water increased the risk of acquiring pathogenic intestinal parasites. Finally, because G. intestinalis was the most prevalent pathogenic protozoan, molecular analysis was conducted to establish genetic assemblages and subassemblages of Giardia through sequence-based genotyping of the glutamate dehydrogenase, triose phosphate isomerase, and beta-giardin genes. A total of 14 G. intestinalis-positive samples were genotyped, which revealed the presence of subassemblages AI (n = 1), AII (n = 7), BIII (n = 2), BIV (n = 2), and BIII/BIV (n = 1) as well as a mixed subassemblage AII + BIII (n = 1). Our results indicate that gastrointestinal parasite infections in the tested population were mainly caused by suboptimal water quality. Moreover, molecular typing of G. intestinalis suggested contamination of water by animal- and human-derived cysts.

B-1 cell response in immunity against parasites.

The peritoneal cavity has a microenvironment capable of promoting proliferation, differentiation, and activation of the resident cells and recruitment of blood cells through the capillary network involved in the peritoneum. Among the cells found in the peritoneal cavity, B-1 cells are a particular cell type that contains features that are not very well defined. These cells differ from conventional B lymphocytes (B-2) by phenotypic, functional, and molecular characteristics. B-1 cells can produce natural antibodies, migrate to the inflammatory focus, and have the ability to phagocytose pathogens. However, the role of B-1 cells in immunity against parasites is still not completely understood. Several experimental models have demonstrated that B-1 cells can affect the susceptibility or resistance to parasite infections depending on the model and species. Here, we review the literature to provide information on the peculiarities of B-1 lymphocytes as well as their interaction with parasites.

Use of Mini-FLOTAC and Fill-FLOTAC for rapidly diagnosing parasitic infections in zoo mammals / Utilização do Mini-FLOTAC e Fill-FLOTAC no diagnóstico rápido de infecções parasitárias de mamíferos em zoológicos

Abstract Animals reared in restricted environments are highly susceptible to gastrointestinal infection by helminths and protozoa and therefore zoos are characterized as being parasite-rich environments. Successful implementation of control programs of these parasites in zoo environment depends upon precise and rapid diagnosing of gastrointestinal infections. The aim of this study was to demonstrate the role of the Mini-FLOTAC technique in combination with Fill-FLOTAC for rapidly diagnosing parasitic infections in zoo mammals. Fecal samples were collected from 70 animals in four different zoos located in central and southern Italy. All the samples were analyzed using Mini-FLOTAC in combination with Fill-FLOTAC. Out of the 70 pooled samples examined, 80% (24/30) were positive for at least one parasite. Among the gastrointestinal nematodes, Strongyles were the most frequent (40%), followed by Trichuris spp. (23.3%), Parascaris spp. (13.3%) and Capillaria spp. (3.3%). Among the protozoa, Blastocystis spp., Giardia spp. and Eimeria spp. were detected in 6.6%, 3.3% and 3.3%, respectively. These results show that Mini-FLOTAC in combination with Fill-FLOTAC can be used, not only for rapidly diagnosing parasitic infections in zoo mammals, but also for monitoring control programs in which large numbers of fecal samples need to be examined rapidly and reliably.

Resumo Animais criados em ambiente restritos são altamente suscetíveis a infecção gastrointestinal por helmintos e protozoários, constituindo os zoológicos em ambientes com alta contaminação por parasitos. O sucesso da implementação de programas de controle contra estes parasitos em zoológicos depende do rápido diagnóstico das infecções por parasitas gastrointestinais. O objetivo deste estudo foi demonstrar o papel da técnica do Mini-FLOTAC em combinação com o Fill-FLOTAC no diagnóstico rápido das infecções parasitárias em mamíferos em zoológicos. Amostras de fezes foram coletadas de 70 animais de quatro diferentes zoológicos no centro e sudoeste da Itália. Todas as amostras foram analisadas pela técnica do Mini-FLOTAC em combinação com o Fill-FLOTAC. Do total de 70 pools de fezes examinadas, 80% (24/30) foram positivas para pelo menos um parasito. Entre os nematoides gastrointestinais a maior frequência foi observada para estrongilídeos (40%), seguida por Trichuris spp. (23,3%), Parascaris spp. (13,3%) e Capillaria spp. (3,3%). Entre os protozoários Blastocystis spp., Giardia spp. e Eimeria spp. foram detectados em 6,6%, 3,3% e 3,3%, respectivamente. Estes resultados demonstram que a técnica do Mini-FLOTAC em combinação com o Fill-FLOTAC pode ser utilizada não somente para o diagnóstico rápido das infecções parasitárias em mamíferos em zoológicos, mas também no monitoramento de programas de controle onde grande número de amostras fecais devem ser examinadas de forma rápida e confiável.

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.

Intestinal helminths and protozoan infections in patients with colorectal cancer: prevalence and possible association with cancer pathogenesis.

The purpose of the present study was to determine the prevalence of intestinal helminths and protozoa in colorectal cancer (CRC) patients and to evaluate the possible association between the prevalence and CRC pathogenesis. A total of 200 CRC patients and 200 residents of Tashkent, who had no complaints related to the gastrointestinal tract, were examined by triple coproscopy using a concentration method and estimations of protozoan infection intensity. Of the CRC patients tested, 144 were classified as T1-4N0M0 (without metastases) and 56 were classified as T1-4N1-2M0-1 (with metastases). Parasitological examination was performed during CRC diagnosis before and after surgery and chemotherapy. A significantly higher prevalence of Blastocystis sp., Chilomastix mesnili, Jodamoeba butschlii, and Endolimax nana was found in CRC patients than in the control population (p < 0.0001), amounting to 80, 20, 22.5, and 11.5%, respectively. The high prevalence of Blastocystis sp., as well as the patterns of infection intensity, was stable at all stages of examination. The ratio of the number of CRC patients with and without Blastocystis sp. in the T1-4N0M0 and T1-4N1-2M0-1 groups amounted to 3.3 and 7.0, respectively. The ratios for C. mesnili, E. coli, J. butschlii, and E. nana in both groups were 0.2 and 0.2, 0.07 and 0.07, 0.3 and 0.16, and 0.18 and 0.01, respectively. The prevalence of helminths and Giardia lamblia in CRC patients and the control population was not significantly different. Taken together, these data indicate a possible role for Blastocystis sp. in CRC pathogenesis. Diagnosis, treatment, and further observation of patients with Blastocystis sp. are necessary at all stages of CRC, including during diagnosis and before and after surgery and chemotherapy.

Development of nanoparticle-assisted PCR assay in the rapid detection of brain-eating amoebae.

Brain-eating amoebae (Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri) have gained increasing attention owing to their capacity to produce severe human and animal infections involving the brain. Early detection is a pre-requisite in successful prognosis. Here, we developed a nanoPCR assay for the rapid detection of brain-eating amoebae using various nanoparticles. Graphene oxide, copper and alumina nanoparticles used in this study were characterized using Raman spectroscopy measurements through excitation with a He-Ne laser, while powder X-ray diffraction patterns were taken on a PANanalytical, X'Pert HighScore diffractometer and the morphology of the materials was confirmed using high-resolution transmission electron microscopy (HRTEM). Using nanoparticle-assisted PCR, the results revealed that graphene oxide, copper oxide and alumina nanoparticles significantly enhanced PCR efficiency in the detection of pathogenic free-living amoebae using genus-specific probes. The optimal concentration of graphene oxide, copper oxide and alumina nanoparticles for Acanthamoeba spp. was determined at 0.4, 0.04 and 0.4 µg per mL respectively. For B. mandrillaris, the optimal concentration was determined at 0.4 µg per mL for graphene oxide, copper oxide and alumina nanoparticles, and for Naegleria, the optimal concentration was 0.04, 4.0 and 0.04 µg per mL respectively. Moreover, combinations of these nanoparticles proved to further enhance PCR efficiency. The addition of metal oxide nanoparticles leads to excellent surface effect, while thermal conductivity property of the nanoparticles enhances PCR productivity. These findings suggest that nanoPCR assay has tremendous potential in the clinical diagnosis of parasitic infections as well as for studying epidemiology and pathology and environmental monitoring of other microbes.