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1.
Front Cell Infect Microbiol ; 14: 1384393, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38720960

RESUMEN

The clinical consequences of toxoplasmosis are greatly dependent on the Toxoplasma gondii strain causing the infection. To better understand its epidemiology and design appropriate control strategies, it is important to determine the strain present in infected animals. Serotyping methods are based on the detection of antibodies that react against segments of antigenic proteins presenting strain-specific polymorphic variations, offering a cost-effective, sensitive, and non-invasive alternative to genotyping techniques. Herein, we evaluated the applicability of a panel of peptides previously characterized in mice and humans to serotype sheep and pigs. To this end, we used 51 serum samples from experimentally infected ewes (32 type II and 19 type III), 20 sheep samples from naturally infected sheep where the causative strain was genotyped (18 type II and 2 type III), and 40 serum samples from experimentally infected pigs (22 type II and 18 type III). Our ELISA test results showed that a combination of GRA peptide homologous pairs can discriminate infections caused by type II and III strains of T. gondii in sheep and pigs. Namely, the GRA3-I/III-43 vs. GRA3-II-43, GRA6-I/III-213 vs. GRA6-II-214 and GRA6-III-44 vs. GRA6-II-44 ratios showed a statistically significant predominance of the respective strain-type peptide in sheep, while in pigs, in addition to these three peptide pairs, GRA7-II-224 vs. GRA7-III-224 also showed promising results. Notably, the GRA6-44 pair, which was previously deemed inefficient in mice and humans, showed a high prediction capacity, especially in sheep. By contrast, GRA5-38 peptides failed to correctly predict the strain type in most sheep and pig samples, underpinning the notion that individual standardization is needed for each animal species. Finally, we recommend analyzing for each animal at least 2 samples taken at different time points to confirm the obtained results.


Asunto(s)
Antígenos de Protozoos , Ensayo de Inmunoadsorción Enzimática , Proteínas Protozoarias , Serotipificación , Enfermedades de las Ovejas , Toxoplasma , Toxoplasmosis Animal , Animales , Ovinos , Toxoplasma/genética , Toxoplasma/inmunología , Toxoplasma/clasificación , Toxoplasmosis Animal/diagnóstico , Toxoplasmosis Animal/parasitología , Porcinos , Proteínas Protozoarias/genética , Proteínas Protozoarias/inmunología , Antígenos de Protozoos/genética , Antígenos de Protozoos/inmunología , Enfermedades de las Ovejas/parasitología , Enfermedades de las Ovejas/diagnóstico , Ensayo de Inmunoadsorción Enzimática/métodos , Serotipificación/métodos , Anticuerpos Antiprotozoarios/sangre , Péptidos/inmunología , Enfermedades de los Porcinos/parasitología , Enfermedades de los Porcinos/diagnóstico , Genotipo
2.
Front Vet Sci ; 10: 1214971, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37662990

RESUMEN

The successful isolation of four new Neospora caninum strains from different regions and with different backgrounds (obtained from an abortion storm or congenitally infected and asymptomatic calves) allowed us previously to characterize natural isolates, finding differences in phenotype and microsatellites. Given the variability observed, we wondered in this work whether these differences had consequences in virulence, invasion and vertical transmission using cell cultures and murine neosporosis models. In addition, we performed the genomic analysis and SNP comparative studies of the NcURU isolates. The results obtained in this work allowed us to establish that NcURU isolates are of low virulence and have unique phenotypic characteristics. Likewise, sequencing their genomes has allowed us to delve into the genetic singularities underlying these phenotypes, as well as the common mutated genes. This work opens a new perspective for diagnostic purposes and formulating possible vaccines based on attenuated strains.

3.
Front Cell Infect Microbiol ; 13: 1134471, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37313339

RESUMEN

A variety of intestinal-derived culture systems have been developed to mimic in vivo cell behavior and organization, incorporating different tissue and microenvironmental elements. Great insight into the biology of the causative agent of toxoplasmosis, Toxoplasma gondii, has been attained by using diverse in vitro cellular models. Nonetheless, there are still processes key to its transmission and persistence which remain to be elucidated, such as the mechanisms underlying its systemic dissemination and sexual differentiation both of which occur at the intestinal level. Because this event occurs in a complex and specific cellular environment (the intestine upon ingestion of infective forms, and the feline intestine, respectively), traditional reductionist in vitro cellular models fail to recreate conditions resembling in vivo physiology. The development of new biomaterials and the advances in cell culture knowledge have opened the door to a next generation of more physiologically relevant cellular models. Among them, organoids have become a valuable tool for unmasking the underlying mechanism involved in T. gondii sexual differentiation. Murine-derived intestinal organoids mimicking the biochemistry of the feline intestine have allowed the generation of pre-sexual and sexual stages of T. gondii for the first time in vitro, opening a window of opportunity to tackling these stages by "felinizing" a wide variety of animal cell cultures. Here, we reviewed intestinal in vitro and ex vivo models and discussed their strengths and limitations in the context of a quest for faithful models to in vitro emulate the biology of the enteric stages of T. gondii.


Asunto(s)
Toxoplasma , Animales , Gatos , Ratones , Diferenciación Sexual , Intestinos , Mucosa Intestinal , Biología
4.
Rev. derecho genoma hum ; (58): 163-182, Ene.-jun. 2023.
Artículo en Inglés | IBECS | ID: ibc-231273

RESUMEN

Los avances en las estrategias multiómicas, tanto a nivel analítico como computacional, han llevado al desarrollo de la medicina personalizada, que adapta el tratamiento médico al individuo basado en la comprensión de su composición biológica. Este enfoque tiene el potencial de revolucionar la atención médica, al proporcionar tratamientos más efectivos y eficientes. Sin embargo, la implementación de la medicina personalizada plantea importantes cuestiones éticas, legales y sociales. Las consideraciones éticas y legales en torno a las pruebas multiómicas, los desafíos de implementar la medicina personalizada en países de rentas bajas y el papel de las leyes de propiedad intelectual en la configuración del acceso a tratamientos personalizados son temas de creciente preocupación. Algunas consideraciones incluyen cuestiones de privacidad, consentimiento informado y posibles discriminaciones. Consideraciones relevantes, en términos penales, por los importantes avances que se van a producir en los próximos años en el análisis multiómico. Los estudios ómicos van a conllevar una mayor comprensión de los mecanismos biológicos que contribuyen a enfermedades mentales y comportamientos agresivos (Jakovljevic and Jakovljevic 2019). La biología humana, que subyace a determinados trastornos que tienen gran influencia en la cuestión penal, va a ser explicada mejor por el sistema multicapa que las pruebas multiómicas propician y va a posibilitar biomarcadores bioquímicos de la agresión que nos proporcionarán gran información en los ámbitos penal y criminológico. Un aspecto ético importante es el derecho a la privacidad de la información genética. Los pacientes pueden dudar en someterse a pruebas genéticas si temen que su información sea compartida o utilizada de formas que no pretendían. El consentimiento informado es otra consideración ética y legal importante. ... (AU)


Advances in multi-omics strategies, both analytical and computational, have led to the development of personalized medicine, which tailors medical treatment to the individual based on an understanding of their biological makeup. This approach has the potential to revolutionize medical care by providing more effective and efficient treatments. However, the implementation of personalized medicine raises important ethical, legal, and social issues. Ethical and legal considerations surrounding multiomics testing, the challenges of implementing personalized medicine in low-income countries, and the role of intellectual property laws in shaping access to personalized treatments are issues of growing concern. Some considerations include issues of privacy, informed consent, and possible discrimination, considerations that may apply in criminal terms because of the significant advances that will be made in the coming years in multi-omics analysis. Omics studies are going to lead to a greater understanding of the biological mechanisms that contribute to mental illness and aggressive behaviors (Jakovljevic and Jakovljevic 2019). Human biology, which underlies certain disorders that have a great influence on the criminal issue, will be better explained by the multi-layered system that multi-omics testing provides and will reveal biochemical biomarkers of aggression that will provide us with vital information in the criminal and criminological fields. An important ethical aspect is the right to privacy of genetic information. Patients may hesitate to undergo genetic testing if they fear that their information will be shared or used in ways they did not intend. Informed consent is another important ethical and legal consideration. The potential for discrimination is also an important legal consideration surrounding genetic testing. ... (AU)


Asunto(s)
Humanos , /ética , /legislación & jurisprudencia , Criminología/legislación & jurisprudencia , /métodos , Medicina Legal
5.
Biomedicines ; 11(5)2023 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-37239081

RESUMEN

Measuring the non-pathogenic Torque Teno Virus (TTV) load allows assessing the net immunosuppressive state after kidney transplantation (KTx). Currently, it is not known how exposure to maintenance immunosuppression affects TTV load. We hypothesized that TTV load is associated with the exposure to mycophenolic acid (MPA) and tacrolimus. We performed a prospective study including 54 consecutive KTx. Blood TTV load was measured by an in-house PCR at months 1 and 3. Together with doses and trough blood levels of tacrolimus and MPA, we calculated the coefficient of variability (CV), time in therapeutic range (TTR) and concentration/dose ratio (C/D) of tacrolimus, and the MPA-area under the curve (AUC-MPA) at the third month. TTV load at the first and third month discriminated those patients at risk of developing opportunistic infections between months 1 and 3 (AUC-ROC 0.723, 95%CI 0.559-0.905, p = 0.023) and between months 3 and 6 (AUC-ROC 0.778, 95%CI 0.599-0.957, p = 0.028), respectively, but not those at risk of acute rejection. TTV load did not relate to mean tacrolimus blood level, CV, TTR, C/D and AUC-MPA. To conclude, although TTV is a useful marker of net immunosuppressive status after KTx, it is not related to exposure to maintenance immunosuppression.

6.
Front Cell Infect Microbiol ; 13: 1130901, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36968102

RESUMEN

Toxoplasma gondii is a ubiquitous apicomplexan parasite that can infect virtually any warm-blooded animal. Acquired infection during pregnancy and the placental breach, is at the core of the most devastating consequences of toxoplasmosis. T. gondii can severely impact the pregnancy's outcome causing miscarriages, stillbirths, premature births, babies with hydrocephalus, microcephaly or intellectual disability, and other later onset neurological, ophthalmological or auditory diseases. To tackle T. gondii's vertical transmission, it is important to understand the mechanisms underlying host-parasite interactions at the maternal-fetal interface. Nonetheless, the complexity of the human placenta and the ethical concerns associated with its study, have narrowed the modeling of parasite vertical transmission to animal models, encompassing several unavoidable experimental limitations. Some of these difficulties have been overcome by the development of different human cell lines and a variety of primary cultures obtained from human placentas. These cellular models, though extremely valuable, have limited ability to recreate what happens in vivo. During the last decades, the development of new biomaterials and the increase in stem cell knowledge have led to the generation of more physiologically relevant in vitro models. These cell cultures incorporate new dimensions and cellular diversity, emerging as promising tools for unraveling the poorly understood T. gondii´s infection mechanisms during pregnancy. Herein, we review the state of the art of 2D and 3D cultures to approach the biology of T. gondii pertaining to vertical transmission, highlighting the challenges and experimental opportunities of these up-and-coming experimental platforms.


Asunto(s)
Toxoplasma , Toxoplasmosis , Animales , Humanos , Embarazo , Femenino , Placenta/parasitología , Toxoplasmosis/parasitología , Transmisión Vertical de Enfermedad Infecciosa , Modelos Animales
7.
mBio ; 13(5): e0185922, 2022 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-36069445

RESUMEN

Centrosomes are the main microtubule-organizing center of the cell. They are normally formed by two centrioles, embedded in a cloud of proteins known as pericentriolar material (PCM). The PCM ascribes centrioles with their microtubule nucleation capacity. Toxoplasma gondii, the causative agent of toxoplasmosis, divides by endodyogeny. Successful cell division is critical for pathogenesis. The centrosome, one of the microtubule organizing centers of the cell, plays central roles in orchestrating the temporal and physical coordination of major organelle segregation and daughter cell formation during endodyogeny. The Toxoplasma centrosome is constituted by multiple domains: an outer core, distal from the nucleus; a middle core; and an inner core, proximal to the nucleus. This modular organization has been proposed to underlie T. gondii's cell division plasticity. However, the role of the inner core remains undeciphered. Here, we focus on understanding the function of the inner core by finely studying the localization and role of its only known molecular marker; TgCep250L1. We show that upon conditional degradation of TgCep250L1 parasites are unable to survive. Mutants exhibit severe nuclear segregation defects. In addition, the rest of the centrosome, defined by the position of the centrioles, disconnects from the nucleus. We explore the structural defects underlying these phenotypes by ultrastructure expansion microscopy. We show that TgCep250L1's location changes with respect to other markers, and these changes encompass the formation of the mitotic spindle. Moreover, we show that in the absence of TgCep250L1, the microtubule binding protein TgEB1, fails to localize at the mitotic spindle, while unsegregated nuclei accumulate at the residual body. Overall, our data support a model in which the inner core of the T. gondii centrosome critically participates in cell division by directly impacting the formation or stability of the mitotic spindle. IMPORTANCE Toxoplasma gondii parasites cause toxoplasmosis, arguably the most widespread and prevalent parasitosis of humans and animals. During the clinically relevant stage of its life cycle, the parasites divide by endodyogeny. In this mode of division, the nucleus, containing loosely packed chromatin and a virtually intact nuclear envelope, parcels into two daughter cells generated within a common mother cell cytoplasm. The centrosome is a microtubule-organizing center critical for orchestrating the multiple simultaneously occurring events of endodyogeny. It is organized in two distinct domains: the outer and inner cores. We demonstrate here that the inner core protein TgCEP250L1 is required for replication of T. gondii. Lack of TgCEP250L1 renders parasites able to form daughter cells, while unable to segregate their nuclei. We determine that, in the absence of TgCEP250L1, the mitotic spindle, which is responsible for karyokinesis, does not assemble. Our results support a role for the inner core in nucleation or stabilization of the mitotic spindle in T. gondii.


Asunto(s)
Toxoplasma , Toxoplasmosis , Humanos , Animales , Toxoplasma/metabolismo , Centrosoma/metabolismo , Toxoplasmosis/parasitología , Mitosis , Cromatina/metabolismo
8.
Front Vet Sci ; 9: 889157, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35958312

RESUMEN

Neospora caninum is a leading cause of bovine abortion worldwide. Although the genetic diversity of this apicomplexan parasite has long been recognized, there is little information on whether infection with different genotypes results in different clinical outcomes or whether infection by a given genotype impairs protective immunity against abortion induced by different genotypes. Here, we provide evidence supporting that natural subclinical infection with isolate NcUru3 of N. caninum in a pregnant heifer did not provide protection against abortion caused by a different N. caninum genotype in the subsequent gestation. A Holstein heifer delivered a healthy calf congenitally infected with N. caninum. Specific anti-N. caninum IgG was detected by indirect ELISA in sera obtained from the dam at calving and the calf before ingestion of colostrum, indicating in utero exposure to the parasite in the latter. A N. caninum strain named NcUru3 was isolated and characterized by multilocus microsatellite typing from the brain of this neonate euthanized at 9 days of age. Sixty days after calving, the cow got pregnant, although she aborted spontaneously at ~6 months of gestation. Pathologic examination of the aborted fetus and placenta revealed typical lesions of neosporosis, including encephalitis, myocarditis, hepatitis, myositis, and placentitis. Neospora caninum DNA was amplified from the fetal brain, heart, kidney, and placenta, and multilocus microsatellite typing revealed a genotype that differed from isolate NcUru3 at the level of microsatellite marker 6A (MS6A). Serum obtained from the dam at the time of abortion had IgG that cross-recognized isolate NcUru3, as demonstrated by immunoblotting, indicating that the humoral immune response did not prevent the other genotype from infecting the fetus and inducing fetoplacental lesions and abortion. This is the first description of one same dam transmitting two N. caninum genotypes to her offspring in subsequent gestations.

9.
Front Vet Sci ; 9: 904786, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35664842

RESUMEN

The aim of this work was to identify causes of abortion through laboratory investigations in sheep flocks in Uruguay. One hundred cases of abortion, comprising 58 fetuses, 36 fetuses with their placentas, and 6 placentas were investigated in 2015-2021. Cases were subjected to gross and microscopic pathologic examinations, and microbiological and serological testing for the identification of causes of abortion, including protozoal, bacterial, and viral pathogens. An etiologic diagnosis was determined in 46 (46%) cases, including 33 (33%) cases caused by infectious pathogens, as determined by the detection of a pathogen along with the identification of fetoplacental lesions attributable to the detected pathogen. Twenty-seven cases (27%) were caused by Toxoplasma gondii, 5 (5%) by Campylobacter fetus subspecies fetus, and 1 (1%) by an unidentified species of Campylobacter. Fourteen cases (14%) had inflammatory and/or necrotizing fetoplacental lesions compatible with an infectious etiology. Although the cause for these lesions was not clearly identified, T. gondii was detected in 4 of these cases, opportunistic bacteria (Bacillus licheniformis, Streptococcus sp.) were isolated in 2 cases, and bovine viral diarrhea virus 1 subtype i (BVDV-1i) was detected in another. Campylobacter jejuni was identified in 1 (1%) severely autolyzed, mummified fetus. BVDV-2b was identified incidentally in one fetus with an etiologic diagnosis of toxoplasmosis. Microscopic agglutination test revealed antibodies against ≥1 Leptospira serovars in 15/63 (23.8%) fetuses; however, Leptospira was not identified by a combination of qPCR, culture, fluorescent antibody testing nor immunohistochemistry. Neospora caninum, Chlamydia abortus, Chlamydia pecorum, Coxiella burnetii and border disease virus were not detected in any of the analyzed cases. Death was attributed to dystocia in 13 (13%) fetuses delivered by 8 sheep, mostly from one highly prolific flock. Congenital malformations including inferior prognathism, a focal hepatic cyst, and enterohepatic agenesis were identified in one fetus each, the latter being the only one considered incompatible with postnatal life. Toxoplasmosis, campylobacteriosis and dystocia were the main identified causes of fetal losses. Despite the relatively low overall success rate in establishing an etiologic diagnosis, a systematic laboratory workup in cases of abortion is of value to identify their causes and enables zoonotic pathogens surveillance.

11.
Microorganisms ; 9(12)2021 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-34946106

RESUMEN

Microtubule organizing centers (MTOCs) perform critical cellular tasks by nucleating, stabilizing, and anchoring microtubule's minus ends. These capacities impact tremendously a wide array of cellular functions ranging from ascribing cell shape to orchestrating cell division and generating motile structures, among others. The phylum Apicomplexa comprises over 6000 single-celled obligate intracellular parasitic species. Many of the apicomplexan are well known pathogens such as Toxoplasma gondii and the Plasmodium species, causative agents of toxoplasmosis and malaria, respectively. Microtubule organization in these parasites is critical for organizing the cortical cytoskeleton, enabling host cell penetration and the positioning of large organelles, driving cell division and directing the formation of flagella in sexual life stages. Apicomplexans are a prime example of MTOC diversity displaying multiple functional and structural MTOCs combinations within a single species. This diversity can only be fully understood in light of each organism's specific MT nucleation requirements and their evolutionary history. Insight into apicomplexan MTOCs had traditionally been limited to classical ultrastructural work by transmission electron microscopy. However, in the past few years, a large body of molecular insight has emerged. In this work we describe the latest insights into nuclear MTOC biology in two major human and animal disease causing Apicomplexans: Toxoplasma gondii and Plasmodium spp.

12.
Front Microbiol ; 12: 751775, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34721355

RESUMEN

Mitochondria are vital organelles of eukaryotic cells, participating in key metabolic pathways such as cellular respiration, thermogenesis, maintenance of cellular redox potential, calcium homeostasis, cell signaling, and cell death. The phylum Apicomplexa is entirely composed of obligate intracellular parasites, causing a plethora of severe diseases in humans, wild and domestic animals. These pathogens include the causative agents of malaria, cryptosporidiosis, neosporosis, East Coast fever and toxoplasmosis, among others. The mitochondria in Apicomplexa has been put forward as a promising source of undiscovered drug targets, and it has been validated as the target of atovaquone, a drug currently used in the clinic to counter malaria. Apicomplexans present a single tubular mitochondria that varies widely both in structure and in genomic content across the phylum. The organelle is characterized by massive gene migrations to the nucleus, sequence rearrangements and drastic functional reductions in some species. Recent third generation sequencing studies have reignited an interest for elucidating the extensive diversity displayed by the mitochondrial genomes of apicomplexans and their intriguing genomic features. The underlying mechanisms of gene transcription and translation are also ill-understood. In this review, we present the state of the art on mitochondrial genome structure, composition and organization in the apicomplexan phylum revisiting topological and biochemical information gathered through classical techniques. We contextualize this in light of the genomic insight gained by second and, more recently, third generation sequencing technologies. We discuss the mitochondrial genomic and mechanistic features found in evolutionarily related alveolates, and discuss the common and distinct origins of the apicomplexan mitochondria peculiarities.

13.
Mol Biol Rep ; 48(6): 5013-5021, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34164751

RESUMEN

Neospora caninum, Toxoplasma gondii and Hammondia spp. are coccidian parasites similar in morphology. Molecular techniques are necessary to detect parasite DNA isolated from stool samples in wild canids because they were reported as definitive hosts of N. caninum life cycle. The objective of this study was to develop a highly sensitive and accurate molecular method for the identification of coccidian Apicomplexa parasites in crab-eating fox (Cerdocyon thous) and pampas fox (Lycalopex gymnocercus). Tissue samples from road-killed animals (pampas fox = 46, crab-eating fox = 55) and feces (pampas fox = 84, crab-eating fox = 2) were collected, and species were diagnosed through molecular assay. PCR was used for the amplification of a fragment of the coccidian Apicomplexa nss-rRNA gene. Additionally, we developed a novel real-time PCR TaqMan™ probe approach to detect T. gondii- Hammondia spp. and N. caninum. This is the first report of N. caninum DNA in pampas fox feces (n = 1), thus it was also detected from pampas fox tissues (n = 1). Meanwhile, T. gondii was found in tissues of pampas (n = 1) and crab-eating (n = 1) foxes and H. triffittae in one crab-eating fox tissue. Despite the low percentage (2.5%) of positive samples, the molecular method developed in this study proved to be highly sensitive and accurate allowing to conduct an extensive monitoring analysis for these parasites in wildlife.


Asunto(s)
Apicomplexa/genética , Zorros/parasitología , Infecciones por Protozoos/diagnóstico , Animales , Animales Salvajes/genética , Apicomplexa/patogenicidad , Coccidios/genética , Coccidios/parasitología , Heces/microbiología , Heces/parasitología , Conducta Alimentaria , Zorros/genética , Epidemiología Molecular/métodos , Neospora/genética , Neospora/patogenicidad , Parásitos/genética , Reacción en Cadena de la Polimerasa/métodos , Infecciones por Protozoos/genética , Uruguay
15.
Genome Res ; 31(5): 823-833, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33906964

RESUMEN

Neospora caninum primarily infects cattle, causing abortions, with an estimated impact of a billion dollars on the worldwide economy annually. However, the study of its biology has been unheeded by the established paradigm that it is virtually identical to its close relative, the widely studied human pathogen Toxoplasma gondii By revisiting the genome sequence, assembly, and annotation using third-generation sequencing technologies, here we show that the N. caninum genome was originally incorrectly assembled under the presumption of synteny with T. gondii We show that major chromosomal rearrangements have occurred between these species. Importantly, we show that chromosomes originally named Chr VIIb and VIII are indeed fused, reducing the karyotype of both N. caninum and T. gondii to 13 chromosomes. We reannotate the N. caninum genome, revealing more than 500 new genes. We sequence and annotate the nonphotosynthetic plastid and mitochondrial genomes and show that although apicoplast genomes are virtually identical, high levels of gene fragmentation and reshuffling exist between species and strains. Our results correct assembly artifacts that are currently widely distributed in the genome database of N. caninum and T. gondii and, more importantly, highlight the mitochondria as a previously oversighted source of variability and pave the way for a change in the paradigm of synteny, encouraging rethinking the genome as basis of the comparative unique biology of these pathogens.


Asunto(s)
Coccidiosis , Neospora , Toxoplasma , Animales , Bovinos , Coccidiosis/veterinaria , Femenino , Cariotipo , Neospora/genética , Embarazo , Toxoplasma/genética
16.
Front Cell Infect Microbiol ; 10: 608291, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33365279

RESUMEN

Toxoplasma gondii is a widely prevalent protozoan parasite member of the phylum Apicomplexa. It causes disease in humans with clinical outcomes ranging from an asymptomatic manifestation to eye disease to reproductive failure and neurological symptoms. In farm animals, and particularly in sheep, toxoplasmosis costs the industry millions by profoundly affecting their reproductive potential. As do all the parasites in the phylum, T. gondii parasites go through sexual and asexual replication in the context of an heteroxenic life cycle involving members of the Felidae family and any warm-blooded vertebrate as definitive and intermediate hosts, respectively. During sexual replication, merozoites differentiate into female and male gametes; their combination gives rise to a zygotes which evolve into sporozoites that encyst and are shed in cat's feces as environmentally resistant oocysts. During zygote formation T. gondii parasites are diploid providing the parasite with a window of opportunity for genetic admixture making this a key step in the generation of genetic diversity. In addition, oocyst formation and shedding are central to dissemination and environmental contamination with infectious parasite forms. In this minireview we summarize the current state of the art on the process of gametogenesis. We discuss the unique structures of macro and microgametes, an insight acquired through classical techniques, as well as the more recently attained molecular understanding of the routes leading up to these life forms by in vitro and in vivo systems. We pose a number of unanswered questions and discuss these in the context of the latest findings on molecular cues mediating stage switching, and the implication for the field of newly available in vitro tools.


Asunto(s)
Toxoplasma , Toxoplasmosis Animal , Animales , Gatos , Femenino , Gametogénesis , Masculino , Oocistos , Ovinos , Esporozoítos , Toxoplasma/genética
18.
Artículo en Inglés | MEDLINE | ID: mdl-32714878

RESUMEN

Apicomplexa are obligate intracellular parasites which cause various animal and human diseases including malaria, toxoplasmosis, and cryptosporidiosis. They proliferate by a unique mechanism that combines physically separated semi-closed mitosis of the nucleus and assembly of daughter cells by internal budding. Mitosis occurs in the presence of a nuclear envelope and with little appreciable chromatin condensation. A long standing question in the field has been how parasites keep track of their uncondensed chromatin chromosomes throughout their development, and hence secure proper chromosome segregation during division. Past work demonstrated that the centromeres, the region of kinetochore assembly at chromosomes, of Toxoplasma gondii remain clustered at a defined region of the nuclear periphery proximal to the main microtubule organizing center of the cell, the centrosome. We have proposed that this mechanism is likely involved in the process. Here we set out to identify underlying molecular players involved in centromere clustering. Through pharmacological treatment and structural analysis we show that centromere clustering is not mediated by persistent microtubules of the mitotic spindle. We identify the chromatin binding factor a homolog of structural maintenance of chromosomes 1 (SMC1). Additionally, we show that both TgSMC1, and a centromeric histone, interact with TgExportin1, a predicted soluble component of the nuclear pore complex. Our results suggest that the nuclear envelope, and in particular the nuclear pore complex may play a role in positioning centromeres in T. gondii.


Asunto(s)
Toxoplasma , Animales , Centrómero , Segregación Cromosómica , Cromosomas Humanos Par 1 , Humanos , Poro Nuclear , Toxoplasma/genética
19.
Rev. cient. Esc. Univ. Cienc. Salud ; 7(1): 22-28, ene.-jun. 2020. tab, graf
Artículo en Español | LILACS | ID: biblio-1223261

RESUMEN

Según la Organización Mundial dela Salud (OMS), entre el 60 y 90% de la población infantil presenta lesiones cariosas concavitación. Las patologías pulpares son consecuencia de la evolución de la caries o traumatismo dental, manifestándose con dolor, inflamación o infección, que obliga a los pacientesa acudir de forma urgente a la consulta odontológica con cuadros de pulpitis reversible, irreversible o necrosis pulpar. Dependiendo dela gravedad de la patología, esta puede intervenirse mediante terapias curativas y cuando ha alcanzado un nivel muy avanzado, laúnica opción es la exodoncia, dejando secuelas a corto, mediano y largo plazo en el niño. Objetivo: Analizar las diferentes patologías pulpares en molares de ciduos de pacientes infantiles entre 5 y 9 años que acuden a la clínica de Odontopediatría de la Facultad de Odontología de la Universidad Nacional Autónoma de Honduras (UNAH) durante 2016-2018.Pacientes y métodos: Estudio descriptivo, retrospectivo y cuantitativo.Se recolectaron historias clínicas de niños entre 5 y 9 años que acudieron entre 2014 -2016 con una muestra de 310 expedientes de un universo de1605. Resultados: Predominaron las patologías pulpares en el género masculino (54.2%). La caries dental fue la etiología más registrada (77.34%),predominó la pulpitis reversible (9.3%), el órgano dentario más afectado, en el sistema de nomenclatura FDI, (Federation Dentaire Internationale), fue el primer molar deciduo inferior izquierdo (7,4). El tratamiento más realizado fue pulpotomía (15.2%). Conclusión: en la población infantil la caries dental no tratada evolucionó en su mayoría apulpitis reversible...(AU)


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Niño , Pulpitis , Caries Dental/diagnóstico , Traumatismos de los Dientes , Pulpa Dental
20.
Pesqui. vet. bras ; 40(5): 325-332, May 2020. tab, graf
Artículo en Inglés | VETINDEX, LILACS | ID: biblio-1135637

RESUMEN

A case series study was conducted to determine the frequency of causes of abortion in dairy cattle in Uruguay. The sample size of 102 cases was composed of 53 fetuses, 35 fetuses with placentas, and 14 placentas without an associated fetus. All cases underwent gross and microscopic pathologic examinations as well as microbiological and serological testing. The etiology was determined in 54 (53%) of cases, 51 of which were caused by infectious agents. Within the observed 102 cases, 30 (29%) were caused by Neospora caninum, six (6%) by Coxiella burnetii and two (2%) by Campylobacter fetus subsp. venerealis. Bovine Parainfluenza-3 virus and Salmonella enterica serovar Newport caused one abortion each. Opportunistic bacteria (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes, and Providencia stuartii) were associated with 11 abortions. In two cases the fetal death was attributed to dystocia, and in one case the fetus had a congenital mesothelioma. Bovine viral diarrhea virus (BVDV) infection was identified in three fetuses; two of which were co-infected with and had typical lesions of N. caninum. No lesions were observed in the other fetus infected by BVDV. Leptospira interrogans was identified in one fetus without lesions. Despite the relatively low overall success rate in establishing an etiological diagnosis in cases of abortion in cattle, a systemic workup of bovine abortion is necessary to establish prevention and control strategies. This also facilitates monitoring and surveillance of reproductive diseases in dairy cattle, some of which represent a risk to public health.(AU)


Uma série de casos foi estudada para determinar a frequência de causas do aborto em bovinos leiteiros no Uruguai. A amostra, de 102 casos, foi composta por 53 fetos, 35 fetos com placentas e 14 placentas sem feto associado. Todos os casos foram submetidos a exames patológicos macroscópicos e microscópicos, além de testes microbiológicos e sorológicos. A etiologia foi determinada em 54 (53%) dos casos, 51 dos quais foram causados por agentes infecciosos. Nos 102 casos observados, 30 (29%) foram causados por Neospora caninum, seis (6%) por Coxiella burnetii e dois (2%) por Campylobacter fetus subsp. venerealis. O vírus da Parainfluenza-3 e Salmonella enterica serovar Newport causaram um aborto cada. Bactérias oportunistas (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes e Providencia stuartii) foram associadas a 11 abortos. Em dois casos, a morte fetal foi atribuída a distocia e, em um caso, o feto apresentava mesotelioma congênito. A infecção pelo vírus da diarreia viral bovina (BVDV) foi identificada em três fetos; dois dos quais foram co-infectados e apresentavam lesões típicas de N. caninum. Não foram observadas lesões no outro feto infectado pelo BVDV. Leptospira interrogans foi identificada em um feto sem lesões. Apesar da relativamente baixa taxa de sucesso no diagnóstico etiológico nos casos de aborto em bovinos, é necessário o diagnóstico sistemático dos abortos para estabelecer estratégias de prevenção e controle. Isso também facilita o monitoramento e a vigilância de doenças reprodutivas em bovinos leiteiros, algumas das quais representam um risco para a saúde pública.(AU)


Asunto(s)
Animales , Femenino , Embarazo , Bovinos , Campylobacter fetus , Infecciones por Campylobacter/veterinaria , Coxiella burnetii , Coccidiosis/veterinaria , Neospora , Aborto Veterinario/etiología , Aborto Veterinario/patología , Uruguay , Leptospira , Leptospirosis/veterinaria
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