RESUMEN

Despite global efforts to assess the early response and persistence of SARS-CoV-2 antibodies in patients infected with or recovered from COVID-19, our understanding of the factors affecting its dynamics remains limited. This work aimed to evaluate the early and convalescent immunity of outpatients infected with SARS-CoV-2 and to determine the factors that affect the dynamics and persistence of the IgM and IgG antibody response. Seropositivity of volunteers from Mexico City and the State of Mexico, Mexico, was evaluated by ELISA using the recombinant receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein for 90 days, at different time points (1, 15, 45, 60, and 90 days) after molecular diagnosis (RT-qPCR). Gender, age range, body mass index (BMI), comorbidities, and clinical spectrum of disease were analyzed to determine associations with the dynamics of anti-SARS-CoV-2 antibodies. On 90 days post-infection, individuals with moderate and asymptomatic disease presented the lowest levels of IgM, while for IgG, at the same time, the highest levels occurred with mild and moderate disease. The IgM and IgG levels were related to the clinical spectrum of disease, BMI, and the presence/absence of comorbidities through regression trees. The results suggest that the dynamics of anti-SARS-CoV-2 IgM and IgG antibodies in outpatients could be influenced by the clinical spectrum of the disease. In addition, the persistence of antibodies against SARS-CoV-2 could be related to the clinical spectrum of the disease, BMI, and the presence/absence of comorbidities.

Asunto(s)

COVID-19 , Humanos , SARS-CoV-2 , Anticuerpos Antivirales , Inmunoglobulina G , Inmunoglobulina M , Inmunidad

RESUMEN

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.

Asunto(s)

Amebiasis , Disentería Amebiana , Entamoeba histolytica , Entamoeba , Humanos , Entamoeba histolytica/genética , Ecosistema , Amebiasis/diagnóstico , Amebiasis/terapia , Amebiasis/parasitología , Disentería Amebiana/diagnóstico , Disentería Amebiana/terapia , Disentería Amebiana/parasitología , Intestinos , Entamoeba/genética

RESUMEN

Blastocystis spp. is a unicellular organism that resides in digestive tract of various vertebrates, with a worldwide distribution and a variable prevalence. For many years, Blastocystis spp. was considered a cyst of a flagellate, a fungus, or a saprophyte yeast of the digestive tract; in 1996, it is placed in the group of stramenopiles (heterokonts). Since its new classification, many questions have arisen around this protist about its role as a pathogen or non-pathogen organism. Recent evidence indicates that Blastocystis spp. participates in the immune inflammatory response in the intestinal microbiome generating an anti-inflammatory response, showing a lower concentration of fecal inflammatory markers in infected human hosts. Here, we review recent findings on the regulatory function of Blastocystis spp. in the immune inflammatory response to comprehend the purpose of Blastocystis spp. in health and disease, defining if Blastocystis spp. is really a pathogen, a commensal or even a mutualist in the human gut microbiome.

Asunto(s)

Infecciones por Blastocystis , Blastocystis , Microbioma Gastrointestinal , Animales , Antiinflamatorios , Infecciones por Blastocystis/epidemiología , Heces/microbiología , Humanos

RESUMEN

An estimated 3.5 billion people are colonized by intestinal parasites worldwide. Intestinal parasitic eukaryotes interact not only with the host but also with the intestinal microbiota. In this work, we studied the relationship between the presence of multiple enteric parasites and the community structures of gut bacteria and eukaryotes in an asymptomatic mother-child cohort from a semirural community in Mexico. Fecal samples were collected from 46 mothers and their respective children, with ages ranging from 2 to 20 months. Mothers and infants were found to be multiparasitized by Blastocystis hominis, Entamoeba dispar, Endolimax nana, Chilomastix mesnili, Iodamoeba butshlii, Entamoeba coli, Hymenolepis nana, and Ascaris lumbricoides. Sequencing of bacterial 16S rRNA and eukaryotic 18S rRNA genes showed a significant effect of parasite exposure on bacterial beta-diversity, which explained between 5.2% and 15.0% of the variation of the bacterial community structure in the cohort. Additionally, exposure to parasites was associated with significant changes in the relative abundances of multiple bacterial taxa, characterized by an increase in Clostridiales and decreases in Actinobacteria and Bacteroidales. Parasite exposure was not associated with changes in intestinal eukaryote relative abundances. However, we found several significant positive correlations between intestinal bacteria and eukaryotes, including Oscillospira with Entamoeba coli and Prevotella stercorea with Entamoeba hartmanni, as well as the co-occurrence of the fungus Candida with Bacteroides and Actinomyces, Bifidobacterium, and Prevotella copri and the fungus Pichia with Oscillospira. The parasitic exposure-associated changes in the bacterial community structure suggest effects on microbial metabolic routes, host nutrient uptake abilities, and intestinal immunity regulation in host-parasite interactions. IMPORTANCE The impact of intestinal eukaryotes on the prokaryotic microbiome composition of asymptomatic carriers has not been extensively explored, especially in infants and mothers with multiple parasitic infections. In this work, we studied the relationship between protist and helminth parasite colonization and the intestinal microbiota structure in an asymptomatic population of mother-child binomials from a semirural community in Mexico. We found that the presence of parasitic eukaryotes correlated with changes in the bacterial gut community structure in the intestinal microbiota in an age-dependent way. Parasitic infection was associated with an increase in the relative abundance of the class Clostridia and decreases of Actinobacteria and Bacteroidia. Parasitic infection was not associated with changes in the eukaryote community structure. However, we observed strong positive correlations between bacterial and other eukaryote taxa, identifying novel relationships between prokaryotes and fungi reflecting interkingdom interactions within the human intestine.

Asunto(s)

Bacterias/genética , Heces/parasitología , Microbioma Gastrointestinal/genética , Helmintos/fisiología , Parasitosis Intestinales/epidemiología , Parásitos/fisiología , Adolescente , Adulto , Animales , Bacterias/clasificación , Estudios de Cohortes , Femenino , Microbioma Gastrointestinal/fisiología , Helmintos/genética , Interacciones Huésped-Parásitos , Humanos , Lactante , México/epidemiología , Persona de Mediana Edad , Modelos Estadísticos , Madres , Parásitos/clasificación , Parásitos/genética , ARN Ribosómico 16S/genética , Población Rural/estadística & datos numéricos , Adulto Joven

RESUMEN

The etiological agent of human amoebiasis is the protozoan parasite E. histolytica; the disease is still an endemic infection in some countries and the outcome of infection in the host infection can range from asymptomatic intestinal infection to intestinal or liver invasive forms of the disease. The invasive character of this parasite is multifactorial and mainly due to the differential expression of multiple pathogenic genes. The aim of the present work was to measure the differential expression of some genes in different specimens of patients with amoebic liver abscess (ALA) and specimens of genital amoebiasis (AG) by RT-qPCR. Results show that the expression of genes is different in both types of samples. Almost all studied genes were over expressed in both sets of patients; however, superoxide dismutase (Ehsod), serine threonine isoleucine rich protein (Ehstirp), peroxiredoxin (Ehprd) and heat shock protein 70 and 90 (Ehhsp-70, EHhsp-90) were higher in AG biopsies tissue. Furthermore, cysteine proteinases 5 and 2 (Ehcp5, Ehcp2), lectin (Ehgal/galnaclectin) and calreticulin (Ehcrt) genes directly associate with pathogenic mechanisms of E. histolytica had similar over expression in both AG and ALA samples. In summary the results obtained show that trophozoites can regulate the expression of their genes depending on stimuli or environmental conditions, in order to regulate their pathogenicity and ensure their survival in the host.

RESUMEN

The Wnt signaling pathway is a crucial regulator of the intestinal epithelium homeostasis and is altered in most colon cancers. While the role of aberrant canonical, ß-catenin-dependent Wnt signaling has been well established in colon cancer promotion, much less is known about the role played by noncanonical, ß-catenin-independent Wnt signaling in this type of cancer. This work aimed to characterize the noncanonical signal transduction pathway in colon cancer cells. To this end, we used the prototype noncanonical ligand, Wnt5a, in comparison with Wnt3a, the prototype of a canonical ß-catenin activating ligand. The analysis of the expression profile of Wnt receptors in colon cancer cell lines showed a clear increase in both level expression and variety of Frizzled receptor types expressed in colon cancer cells compared with non-malignant cells. We found that Wnt5a activates a typical Wnt/Ca++ - noncanonical signaling pathway in colon malignant cells, inducing the hyperphosphorylation of Dvl1, Dvl2 and Dvl3, promoting Ca++ mobilization as a result of phospholipase C (PLC) activation via pertussis toxin-sensitive G-protein, and inducing PLC-dependent cell migration. We also found that while the co-receptor Ror2 tyrosine kinase activity is not required for Ca++ mobilization-induced by Wnt5a, it is required for the inhibitory effects of Wnt5a on the ß-catenin-dependent transcriptional activity. Unexpectedly, we found that although the prototype canonical Wnt3a ligand was unique in stimulating the ß-catenin-dependent transcriptional activity, it also simultaneously activated PLC, promoted Ca++ mobilization, and induced Rho kinase and PLC-dependent cell migration. Our data indicate, therefore, that a Wnt ligand can activate at the same time the so-called Wnt canonical and noncanonical pathways inducing the formation of complex signaling networks to integrate both pathways in colon cancer cells.

Asunto(s)

Neoplasias del Colon/metabolismo , Proteínas Wnt/metabolismo , Vía de Señalización Wnt , Animales , Calcio/metabolismo , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Neoplasias del Colon/patología , Proteínas de Unión al GTP/metabolismo , Humanos , Ligandos , Ratones , Modelos Biológicos , Toxina del Pertussis/farmacología , Fosforilación/efectos de los fármacos , Isoformas de Proteínas/metabolismo , Estabilidad Proteica/efectos de los fármacos , Receptores Huérfanos Similares al Receptor Tirosina Quinasa/metabolismo , Receptores Wnt/metabolismo , Factores de Tiempo , Transcripción Genética/efectos de los fármacos , Vía de Señalización Wnt/efectos de los fármacos , beta Catenina/metabolismo

RESUMEN

Calreticulin (CRT) is a highly conserved protein in the endoplasmic reticulum that plays important roles in the regulation of key cellular functions. Little is known about the participation of E. histolytica CRT (EhCRT) in the processes of pathogenicity or in the modulation of the host immune response. The aim of this study was to evaluate the role of CRT in the proliferation and the cytokine profile in peripheral blood mononuclear cells (PBMCs) from patients with amebic liver abscess (ALA) during the acute phase (AP-ALA) of the disease compared to patients during the resolution phase (R-ALA). The PBMCs from each participant were cocultured with EhCRT and tested by the colorimetric method to evaluate their proliferation index (PI). The supernatants were subjected to an enzyme-linked immunosorbent assay (ELISA) to evaluate the concentration of cytokines. The mean values of all groups were compared using the independent t-test. When the PIs of individuals without diagnosis of liver abscess (NEG) were compared, there were no statistically significant differences in the proliferation of PBMCs between patients with AP-ALA and R-ALA when stimulated with EhCRT or concanavalin A (ConA). However, the levels of interleukins [IL-6, IL-10, granulocyte colony stimulating factor (GCSF), and transforming growth factor ß1 (TGFß1)] were higher in patients with AP-ALA, whereas in patients with R-ALA, higher levels of interferon gamma (IFNγ) were detected. These results suggest that EhCRT acts as a mitogen very similar to the activity of ConA. In addition, EhCRT is an excellent immunogen for the specific activation of PBMCs, inducing the differential expression of ILs depending on the outcome of disease, determining the type of immune response: a Th2 cytokine profile during the acute phase and a Th1 profile during the resolution phase.

Asunto(s)

Calreticulina/metabolismo , Citocinas/biosíntesis , Entamoeba histolytica/crecimiento & desarrollo , Entamoeba histolytica/inmunología , Interacciones Huésped-Patógeno , Leucocitos Mononucleares/parasitología , Absceso Hepático Amebiano/parasitología , Calreticulina/inmunología , Células Cultivadas , Técnicas de Cocultivo , Medios de Cultivo/química , Entamoeba histolytica/aislamiento & purificación , Ensayo de Inmunoadsorción Enzimática , Humanos , Leucocitos Mononucleares/inmunología , Proteínas Protozoarias/inmunología , Proteínas Protozoarias/metabolismo

RESUMEN

Blastocystis subtype 3 (ST3) is a parasitic protist found in the digestive tract of symptomatic and asymptomatic humans around the world. While this parasite exhibits a high prevalence in the human population, its true geographic distribution and global genetic diversity are still unknown. This gap in knowledge limits the understanding of the spread mechanisms, epidemiology, and impact that this parasite has on human populations. Herein, we provided new data on the geographical distribution and genetic diversity of Blastocystis ST3 from a rural human population in Mexico. To do so, we collected and targeted the SSU-rDNA region in fecal samples from this population and further compared its genetic diversity and structure with that previously observed in populations of Blastocystis ST3 from other regions of the planet. Our analyses reveled that diversity of Blastocystis ST3 showed a high haplotype diversity and genetic structure to the world level; however, they were low in the Morelos population. The haplotype network revealed a common widespread haplotype from which the others were generated recently. Finally, our results suggested a recent expansion of the diversity of Blastocystis ST3 worldwide.

Asunto(s)

Infecciones por Blastocystis/genética , Blastocystis/genética , ADN Ribosómico/genética , Variación Genética , Adolescente , Adulto , Blastocystis/patogenicidad , Infecciones por Blastocystis/epidemiología , Infecciones por Blastocystis/parasitología , Niño , Preescolar , ADN Protozoario , Heces/parasitología , Femenino , Tracto Gastrointestinal/parasitología , Tracto Gastrointestinal/patología , Haplotipos/genética , Humanos , Masculino , México/epidemiología , Persona de Mediana Edad , Filogenia , Población Rural , Adulto Joven

RESUMEN

NK cells are important in innate immunity for their capacity to kill infected or cancer cells. The killer cell immunoglobulin-like receptors (KIR) are a family of polymorphic genes with inhibitory and activating functions. The main driving force for gastric cancer (GC) development is a chronic response, which causes an increase of NK cells in the gastric mucosa. The aim of this work was to study polymorphisms in KIR genes in patients with either GC or non-atrophic gastritis (NAG). We studied 242 patients (130 with NAG and 112 with GC) and contrasted with 146 asymptomatic individuals. We analyzed diversity in the content and localization of KIR genes in the different clinical groups studied. Four activating and one inhibitory genes were associated with GC: 2DS1 (OR 3.41), 2DS3 (OR 4.66), 2DS5 (OR 2.25), 3DS1 (OR 3.35) and 2DL5 (OR 3.6). The following were also found as risk factors for GC: Bx genotype (OR 4.2), Bx-Bx centromere-telomere (OR 2.55), cA01|cB03 (OR 36.39) and tB01|tB01 (OR 7.55) gene content and three B motifs (OR 10.9). Polymorphisms in KIR genes were associated with GC and suggest that mutated NK cells may contribute to GC development by increasing gastric mucosa inflammation, leading to constant tissue damage.

Asunto(s)

Polimorfismo Genético , Receptores KIR/genética , Neoplasias Gástricas/genética , Adulto , Anciano , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Células Asesinas Naturales/metabolismo , Células Asesinas Naturales/patología , Masculino , Persona de Mediana Edad , Neoplasias Gástricas/patología

RESUMEN

OBJETIVO: Caracterizar pacientes con indicación de cesárea atendidas en el servicio de ginecología y obstetricia de la clínica médica previsional Asunción ­ MINSA, Juigalpa Chontales, Nicaragua ,2016. DISEÑO: Estudio descriptivo, cuantitativo de corte transversal. Está constituido por 161 mujeres que se les practicó cirugía vía cesárea, se recolectó la información de expedientes clínicos médico legales, del departamento de archivo, que cumplieròn los criterios de inclusión correspondientes. RESULTADOS: El 86.96%se trataba de mujeres en el rango de edad entre 20-35 años, en un 72.05% de educación universitaria, el 54.04% laboraban de acuerdo a su formación profesional, 58.39% eran casadas y el 75.78% procedían del área urbana. De acuerdo a los factores gineco - obstétricos, las pacientes en el estudio no tenían antecedentes personales no patológicos hasta en un 96.89%, con embarazos de término hasta en 83.23%, 42.24% tenían cesáreas anteriores y hasta 72.05% no tenían antecedentes patológicos personales, el 100% recibió atención prenatal, el 86.34% recibió más de 4 atenciones prenatales. 43.48% no presentarón factores de riesgo durante su embarazo y 91.93% no tuvierón factores de riesgo durante el parto. La principal indicación de cesárea hasta en 36.65% precisamente fue cesárea anterior. CONCLUSIONES: Con respecto a las características sociodemográficas, todos estos factores no favorecierón a indicación absoluta de cesárea, no presentarón factores ginecológicos y obstétricos de relevancia que hayan favorecido su indicación absoluta de cesárea, la cual fue la principal causa de indicación para realizar interrupción del embarazo vía alta actual

Asunto(s)

Humanos , Femenino , Embarazo , Servicio de Ginecología y Obstetricia en Hospital , Cesárea

RESUMEN

The coffee berry borer (CBB) Hypothenemus hampei is the most limiting pest of coffee production worldwide. The CBB genome has been recently sequenced; however, information regarding the presence and characteristics of transposable elements (TEs) was not provided. Using systematic searching strategies based on both de novo and homology-based approaches, we present a library of TEs from the draft genome of CBB sequenced by the Colombian Coffee Growers Federation. The library consists of 880 sequences classified as 66% Class I (LTRs: 46%, non-LTRs: 20%) and 34% Class II (DNA transposons: 8%, Helitrons: 16% and MITEs: 10%) elements, including families of the three main LTR (Gypsy, Bel-Pao and Copia) and non-LTR (CR1, Daphne, I/Nimb, Jockey, Kiri, R1, R2 and R4) clades and DNA superfamilies (Tc1-mariner, hAT, Merlin, P, PIF-Harbinger, PiggyBac and Helitron). We propose the existence of novel families: Hypo, belonging to the LTR Gypsy superfamily; Hamp, belonging to non-LTRs; and rosa, belonging to Class II or DNA transposons. Although the rosa clade has been previously described, it was considered to be a basal subfamily of the mariner family. Based on our phylogenetic analysis, including Tc1, mariner, pogo, rosa and Lsra elements from other insects, we propose that rosa and Lsra elements are subfamilies of an independent family of Class II elements termed rosa. The annotations obtained indicate that a low percentage of the assembled CBB genome (approximately 8.2%) consists of TEs. Although these TEs display high diversity, most sequences are degenerate, with few full-length copies of LTR and DNA transposons and several complete and putatively active copies of non-LTR elements. MITEs constitute approximately 50% of the total TEs content, with a high proportion associated with DNA transposons in the Tc1-mariner superfamily.

Asunto(s)

Elementos Transponibles de ADN/genética , Genoma de los Insectos/genética , Secuencias Repetidas Terminales/genética , Gorgojos/genética , Animales , Coffea

RESUMEN

The human gut is a highly complex ecosystem with an extensive microbial community, and the influence of the intestinal microbiota reaches the entire host organism. For example, the microbiome regulates fat storage, stimulates or renews epithelial cells, and influences the development and maturation of the brain and the immune system. Intestinal microbes can protect against infection by pathogenic bacteria, viruses, fungi and parasites. Hence, the maintenance of homeostasis between the gut microbiota and the rest of the body is crucial for health, with dysbiosis affecting disease. This review focuses on intestinal protozoa, especially those still representing a public health problem in Mexico, and their interactions with the microbiome and the host. The decrease in prevalence of intestinal helminthes in humans left a vacant ecological niche that was quickly occupied by protozoa. Although the mechanisms governing the interaction between intestinal microbiota and protozoa are poorly understood, it is known that the composition of the intestinal bacterial populations modulates the progression of protozoan infection and the outcome of parasitic disease. Most reports on the complex interactions between intestinal bacteria, protozoa and the immune system emphasize the protective role of the microbiota against protozoan infection. Insights into such protection may facilitate the manipulation of microbiota components to prevent and treat intestinal protozoan infections. Here we discuss recent findings about the immunoregulatory effect of intestinal microbiota with regards to intestinal colonization by protozoa, focusing on infections by Entamoeba histolytica, Blastocystis spp, Giardia duodenalis, Toxoplasma gondii and Cryptosporidium parvum. The possible consequences of the microbiota on parasitic, allergic and autoimmune disorders are also considered.

Asunto(s)

Disbiosis/inmunología , Microbioma Gastrointestinal/inmunología , Parásitos/inmunología , Parásitos/microbiología , Infecciones por Protozoos/etiología , Animales , Disbiosis/microbiología , Disbiosis/parasitología , Homeostasis , Humanos , México , Infecciones por Protozoos/inmunología , Infecciones por Protozoos/microbiología

RESUMEN

BACKGROUND: This study aimed to determine the frequency of Entamoeba histolytica and Entamoeba dispar infection in school children in the community of Tlaltizapan, in order to understand the dynamics of infection within the school and family spheres of this population. Amoebiasis is an unsolved public health problem and an endemic disease in Mexico. The incidence rate varies depending on the state; the most affected states show the highest numbers of new cases of amoebiasis per year. Previously, we reported the molecular frequency of infection with E. histolytica and/or E. dispar in other rural communities of the state of Morelos. METHODS: Children from 3 schools were studied to estimate the frequency of intestinal parasites through microscopic examination of fresh stool samples. The number of studied individuals were 309 school children. The molecular characterization of E. histolytica or E. dispar was carried out by Polymerase Chain Reaction (PCR) using species-specific primers to amplify short tandem repeats (STR) in non-coding sequences associated with the tRNA gene; the amplified fragments were sequenced and analyzed. RESULTS: Eight different genotypes were obtained from E. dispar isolates with the molecular marker NKD3-D5. None of the cases in which the species E. histolytica was detected developed symptoms attributable to an invasive process of disease. Moreover, the parasitized condition appeared to have no significant impact on the development or nutritional status of affected children. Genotype 1, which corresponds to the reference strain E. dispar SAW760, considered a non-pathogenic amoeba, was the most prevalent. CONCLUSIONS: The comparison of the genotypes of Entamoeba species did not show a correlation between children and their relatives. In this community, the species Entamoeba dispar genotype 1 was the most widespread. Based on the indicators of growth, development and nutrition status, the studied community seems to be reasonably adapted to constant exposure to intestinal parasites, since there were no evidences of a serious impact of the parasitized condition on the children's health.

Asunto(s)

Entamoeba/aislamiento & purificación , Entamebiasis/epidemiología , Parasitosis Intestinales/epidemiología , Adolescente , Animales , Niño , Preescolar , Estudios Transversales , Cartilla de ADN , ADN Protozoario/análisis , Entamoeba/genética , Entamoeba histolytica/genética , Entamoeba histolytica/aislamiento & purificación , Entamebiasis/parasitología , Heces/parasitología , Femenino , Genotipo , Humanos , Parasitosis Intestinales/parasitología , Masculino , México/epidemiología , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia

RESUMEN

Amebiasis is an endemic disease and a public health problem throughout Mexico, although the incidence rates of amebic liver abscess (ALA) vary among the geographic regions of the country. Notably, incidence rates are high in the northwestern states (especially Sonora with a rate of 12.57/100,000 inhabitants) compared with the central region (Mexico City with a rate of 0.69/100,000 inhabitants). These data may be related to host genetic factors that are partially responsible for resistance or susceptibility. Therefore, we studied the association of the HLA-DRB1 and HLA-DQB1 alleles with resistance or susceptibility to ALA in two Mexican populations, one each from Mexico City and Sonora. Ninety ALA patients were clinically diagnosed by serology and sonography. Genomic DNA was extracted from peripheral blood mononuclear cells. To establish the genetic identity of both populations, 15 short tandem repeats (STRs) were analyzed with multiplexed PCR, and the allelic frequencies of HLA were studied by PCR-SSO using LUMINEX technology. The allele frequencies obtained were compared to an ethnically matched healthy control group (146 individuals). We observed that both affected populations differed genetically from the control group. We also found interesting trends in the population from Mexico City. HLA-DQB1*02 allele frequencies were higher in ALA patients compared to the control group (0.127 vs 0.047; p= 0.01; pc= NS; OR= 2.9, 95% CI= 1.09-8.3). The less frequent alleles in ALA patients were HLA-DRB1*08 (0.118 vs 0.238 in controls; p= 0.01; pc= NS; OR= 0.42, 95% CI= 0.19-0.87) and HLA-DQB1*04 (0.109 vs 0.214; p= 0.02; pc= NS; OR= 0.40, 95% CI= 0.20-0.94). The haplotype HLA-DRB1*08/-DQB1*04 also demonstrated a protective trend against the development of this disease (0.081 vs. 0.178; p=0.02; pc=NS; OR= 0.40, 95% CI= 0.16-0.93). These trends suggest that the prevalent alleles in the population of Mexico City may be associated with protection against the development of ALA.

Asunto(s)

Alelos , Resistencia a la Enfermedad/genética , Antígenos de Histocompatibilidad Clase II/genética , Absceso Hepático Amebiano/genética , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Geografía , Antígenos de Histocompatibilidad Clase I/genética , Prueba de Histocompatibilidad , Humanos , Absceso Hepático Amebiano/epidemiología , Masculino , México , Prevalencia

RESUMEN

The role of calreticulin (CRT) in host-parasite interactions has recently become an important area of research. Information about the functions of calreticulin and its relevance to the physiology of Entamoeba parasites is limited. The present work demonstrates that CRT of both pathogenic E. histolytica and nonpathogenic E. dispar species specifically interacted with human C1q inhibiting the activation of the classical complement pathway. Using recombinant EhCRT protein, we demonstrate that CRT interaction site and human C1q is located at the N-terminal region of EhCRT. The immunofluorescence and confocal microscopy experiments show that CRT and human C1q colocalize in the cytoplasmic vesicles and near to the surface membrane of previously permeabilized trophozoites or are incubated with normal human serum which is known to destroy trophozoites. In the presence of peripheral mononuclear blood cells, the distribution of EhCRT and C1q is clearly over the surface membrane of trophozoites. Nevertheless, the level of expression of CRT in situ in lesions of amoebic liver abscess (ALA) in the hamster model is different in both Entamoeba species; this molecule is expressed in higher levels in E. histolytica than in E. dispar. This result suggests that EhCRT may modulate some functions during the early moments of the host-parasite relationship.

Asunto(s)

Calreticulina/inmunología , Vía Clásica del Complemento/inmunología , Entamoeba histolytica/inmunología , Entamoeba histolytica/patogenicidad , Absceso Hepático Amebiano/inmunología , Absceso Hepático Amebiano/parasitología , Regulación de la Expresión Génica/inmunología , Humanos

RESUMEN

Cutaneous amebiasis is the least common clinical form of human amebiasis in Mexico, sexual amebiasis was only occasionally observed before the late 1980s. However, in the last few decades, most of the documented cases of cutaneous amebiasis from around the world are sexually transmitted. We present two cases of sexually transmitted genital amebiasis. The molecular characterization of the Entamoeba species in the affected tissues underlines the importance of an etiological diagnosis using specific and sensitive techniques that avoid the rapid destruction of tissues and the irreversible sequelae to the anatomy and function of the affected organs. In addition, for those interested in the study of the human-amoebic disease relationship and its epidemiology, the detection of a new, mixed infection in an invasive case of amebiasis reveals new perspectives in the study of the extraordinarily complex host-parasite relationship in amebiasis.

Asunto(s)

Amebiasis/diagnóstico , Enfermedades de la Piel/diagnóstico , Adulto , Anciano , Amebiasis/genética , Humanos , Masculino , Enfermedades de la Piel/genética

RESUMEN

In accordance with the 1997 documents of the World Health Organization (WHO), amoebiasis is defined as the infection by the protozoan parasite Entamoeba histolytica with or without clinical manifestations. The only known natural host of E. histolytica is the human with the large intestine as major target organ. This parasite has a very simple life cycle in which the infective form is the cyst, considered a resistant form of parasite: The asymptomatic cyst passers and the intestinal amoebiasis patients are the transmitters; they excrete cysts in their feces, which can contaminate food and water sources. E. histolytica sensu stricto is the potentially pathogenic species and E. dispar is a commensal non-pathogenic Entamoeba. Both species are biochemical, immunological and genetically distinct. The knowledge of both species with different pathogenic phenotypes comes from a large scientific debate during the second half of the 20(th) century, which gave place to the rapid development of diagnostics technology based on molecular and immunological strategies. During the last ten years, knowledge of the new epidemiology of amoebiasis in different geographic endemic and non-endemic areas has been obtained by applying mostly molecular techniques. In the present work we highlight novelties on human infection and the disease that can help the general physician from both endemic and non-endemic countries in their medical practice, particularly, now that emigration is undoubtedly a global phenomenon that is modifying the previous geography of infectious diseases worldwide.

RESUMEN

Entamoeba histolytica calreticulin (EhCRT) is remarkably immunogenic in humans (90-100% of invasive amoebiasis patients). Nevertheless, the study of calreticulin in this protozoan is still in its early stages. The exact location, biological functions, and its role in pathogenesis are yet to be fully understood. The aim of the present work is to determine the location of EhCRT in virulent trophozoites in vivo and the expression of the Ehcrt gene during the development of experimentally induced amoebic liver abscesses (ALA) in hamsters. Antibodies against recombinant EhCRT were used for the immunolocalization of EhCRT in trophozoites through confocal microscopy; immunohistochemical assays were also performed on tissue sections of ALAs at different times after intrahepatic inoculation. The expression of the Ehcrt gene during the development of ALA was estimated through both in situ RT-PCR and real-time RT-PCR. Confocal assays of virulent trophozoites showed a distribution of EhCRT in the cytoplasmic vesicles of different sizes. Apparently, EhCRT is not exported into the hepatic tissue. Real-time RT-PCR demonstrated an over-expression of the Ehcrt gene at 30 min after trophozoite inoculation, reaching a peak at 1-2 h; thereafter, the expression fell sharply to its original levels. These results demonstrate for the first time in an in vivo model of ALA, the expression of Ehcrt gene in E. histolytica trophozoites and add evidence that support CRT as a resident protein of the ER in E. histolytica species. The in vivo experiments suggest that CRT may play an important role during the early stages of the host-parasite relationship, when the parasite is adapting to a new environment, although the protein seems to be constitutively synthesized. Moreover, trophozoites apparently do not export EhCRT into the hepatic tissue in ALA.

Asunto(s)

Calreticulina/metabolismo , Entamoeba histolytica/metabolismo , Absceso Hepático Amebiano/metabolismo , Proteínas Protozoarias/metabolismo , Trofozoítos/metabolismo , Animales , Western Blotting , Calreticulina/genética , Calreticulina/inmunología , Cricetinae , Modelos Animales de Enfermedad , Retículo Endoplásmico/metabolismo , Entamoeba histolytica/genética , Entamoeba histolytica/inmunología , Amplificación de Genes , Expresión Génica , Interacciones Huésped-Parásitos , Hígado/metabolismo , Hígado/parasitología , Hígado/patología , Absceso Hepático Amebiano/parasitología , Absceso Hepático Amebiano/patología , Mesocricetus , Ratones , Ratones Endogámicos BALB C , Microscopía Confocal , Proteínas Recombinantes

RESUMEN

For over 30 years it has been established that the Entamoeba histolytica protozoan included two biologically and genetically different species, one with a pathogenic phenotype called E. histolytica and the other with a non-pathogenic phenotype called Entamoeba dispar. Both of these amoebae species can infect humans. E. histolytica has been considered as a potential pathogen that can cause serious damage to the large intestine (colitis, dysentery) and other extraintestinal organs, mainly the liver (amebic liver abscess), whereas E. dispar is a species that interacts with humans in a commensal relationship, causing no symptoms or any tissue damage. This paradigm, however, should be reconsidered or re-evaluated. In the present work, we report the detection and genotyping of E. dispar sequences of DNA obtained from patients with amebic liver abscesses, including the genotyping of an isolate obtained from a Brazilian patient with a clinical diagnosis of intestinal amebiasis that was previously characterized as an E. dispar species. The genetic diversity and phylogenetic analysis performed by our group has shown the existence of several different genotypes of E. dispar that can be associated to, or be potentiality responsible for intestinal or liver tissue damage, similar to that observed with E. histolytica.

Asunto(s)

Entamebiasis/parasitología , ADN Protozoario/aislamiento & purificación , Entamoeba/clasificación , Entamoeba/genética , Humanos , Filogenia , Reacción en Cadena de la Polimerasa , Especificidad de la Especie

RESUMEN

El análisis de la hormona tiroestimulante (TSH) de tercera generación permite la diferenciación de pacientes con hipertiroidismo real y pacientes con niveles suprimidos de TSH asociados con otras patologías, lo cual era imposible determinar con los análisis de primera y segunda generación

Asunto(s)

Humanos , Hormonas Glicoproteicas de Subunidad alfa/análisis , Hormonas Glicoproteicas de Subunidad alfa/farmacocinética , Hormonas Glicoproteicas de Subunidad alfa/farmacología , Hormonas Glicoproteicas de Subunidad alfa/fisiología , Hormonas Glicoproteicas de Subunidad alfa , Hormonas Glicoproteicas de Subunidad alfa/uso terapéutico , Hipertiroidismo/sangre , Hipertiroidismo/clasificación , Hipertiroidismo/complicaciones , Hipertiroidismo/diagnóstico , Hipertiroidismo/tratamiento farmacológico , Hipertiroidismo/epidemiología , Hipertiroidismo/etiología , Hipertiroidismo/patología , Hipertiroidismo/fisiopatología , Hipertiroidismo/cirugía , Hipertiroidismo/terapia , Hormonas Tiroideas/fisiología