Toxoplasma gondii in Meat for Human Consumption – A Brief Review of the Most Described Strategies for Its Detection and Quantification

Toxoplasmosis is a parasitic zoonotic disease widely distributed worldwide and is caused by the intracellular parasite Toxoplasma gondii. The definitive host of T. gondii is the domestic cat and the entire cat family, in which the sexual stages of the parasite develop. T. gondii can also infect a wide range of intermediate hosts, affecting most warm-blooded animals including humans. In humans, toxoplasmosis is usually asymptomatic in healthy individuals, but can develop lymphadenopathy and nonspecific symptomatology or even be fatal in infants with congenital toxoplasmosis and in immunocompromised patients. Transmission to humans is mainly through food, especially by eating undercooked meat or meat contaminated with tissue cysts. This has led to various public health organizations worldwide monitoring programs on T. gondii in animals intended for human consumption, especially in meat samples. One of the techniques employed in the laboratory is that based on the polymerase chain reaction and some of its variants, which have proven to be valuable tools for the detection of T. gondii in tissues for human consumption and many other types of biological samples. The development of different strategies for the molecular detection of T. gondii has led to the identification and quantification methodologies varying widely among laboratories. Therefore, this chapter reviews the main methods of extraction, purification, detection and quantification of T. gondii DNA in tissue samples from different species destined for human consumption

Subproductos del cacao (Theobroma cacao) como alternativa para la mejora de la dieta balanceada en rumiantes

Cocoa production is estimated at 4.7 million tons per year, of which 90% are waste residues, such as cocoa husks (CC). These agricultural by-products are a source of nutritional compounds of interest to the ruminant sector. Studies carried out on this matter have shown that it has a high percentage of proteins, fiber, phenols, among others, which give it nutraceutical properties. The fiber present in CC has the potential to absorb oils and cholesterol, thus reducing its bioavailability during digestion. Therefore, the objective of this research was to describe and analyze the nutritional properties of cocoa by-products in the induction of a balanced diet for ruminant animals. The analysis was performed by searching the literature review (Scopus, Scielo) during the months of April and May 2022, the guidelines of the PRISMA statement were followed and to establish the search string, the Boléan operators were used. Current evidence suggests the use of cocoa by-products as an alternative for the improvement of the balanced diet in ruminants (under relevant parameters), as a non-conventional alternative raw material in diets for the ruminant sector for its contribution in protein and fiber that helps fattening without detrimental effects on milk production performanceSe estima que la producción de cacao es de 4.7 millones de toneladas por año, de los cuales el 90% son residuos de desecho, tal como la cascara o cascarilla del cacao (CC). Estos subproductos agrícolas son fuente de compuestos nutritivos de interés para el sector de rumiantes. Los estudios realizados en esta materia han demostrado que tiene un alto porcentaje de proteínas, fibra, fenoles entre otros, que le otorgan propiedades nutraceúticas. La fibra presente en la CC tiene el potencial de absorción de aceites y colesterol, reduciendo de esta forma su biodisponibilidad durante la digestión. Por tanto, el objetivo de esta investigación fue describir y analizar las propiedades nutritivas de los subproductos del cacao en la inducción de una dieta balanceada para animales rumiantes. El análisis se realizó mediante la búsqueda de la revisión bibliográfica (Scopus, Scielo) durante los meses de abril y mayo del 2022, se siguió las directrices de la declaración PRISMA y para establecer la cadena de búsqueda se utilizó los operadores boléanos. La evidencia actual sugiere la utilización de los subproductos del cacao como alternativa para la mejora de la dieta balanceada en rumiantes (bajo parámetros pertinentes), como materia prima alternativa no convencional en dietas destinados al sector de rumiantes por su aporte en proteínas y fibra que ayuda al engorde sin efectos perjudícales al rendimiento de producción de leche

Comportamento de variedades sintéticas de milho no Rio Grande do Sul.

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PCR-RLFP characterization of Leishmania spp. in domestic animals from the south-western border of Brazil

Abstract The aim of this study was to characterize Leishmania spp. from canine and feline samples using Polymerase Chain Reaction (PCR)- Restriction Fragment Length Polymorphism (RFLP). It was conducted in the southern region of Brazil, located at border crossings to Argentina and Uruguay. Samples were collected from 116 dogs (Canis lupus familiaris) and 89 cats (Felis catus). The PCR was performed to screen for an LT1 fragment from kinetoplast DNA (kDNA) target gene, and positive samples were subjected to a second PCR for an internal transcribed spacers (ITS1) region from ribosomal DNA (rDNA) target. RFLP was performed using the Haemophilus aegyptius (HAE III) restriction endonuclease (Fermentas ®). Positive samples by PCR ITS1 were sequenced and deposited in NCBI GenBank, and a phylogenetic analysis was developed. We found that 12.9% (15/116) of the samples from dogs were positive. All the 89 cat samples were negative. Positive samples were tested against Leishmania reference strains presenting different patterns in PCR-RFLP, and these samples showed bands denoting similarity to the standard species of Leishmania infantum, proven through sequencing and phylogenetic analysis. The RFLP technique, alone, was shown to be feasible for practical application and confirmation of the involved Leishmania spp

Eco-epidemiological analysis of rickettsial seropositivity in rural areas of Colombia: A multilevel approach

ABSTARCT: Rickettsiosis is a re-emergent infectious disease without epidemiological surveillance in Colombia. This disease is generally undiagnosed and several deadly outbreaks have been reported in the country in the last decade. The aim of this study is to analyze the eco-epidemiological aspects of rickettsial seropositivity in rural areas of Colombia where outbreaks of the disease were previously reported. A cross-sectional study, which included 597 people living in 246 households from nine hamlets in two municipalities of Colombia, was conducted from November 2015 to January 2016. The survey was conducted to collect sociodemographic and household characteristics (exposure) data. Blood samples were collected to determine the rickettsial seropositivity in humans, horses and dogs (IFA, cut-off = 1/128). In addition, infections by rickettsiae were detected in ticks from humans and animals by real-time PCR targeting gltA and ompA genes. Data was analyzed by weighted multilevel clog-log regression model using three levels (person, household and hamlets) and rickettsial seropositivity in humans was the main outcome. Overall prevalence of rickettsial seropositivity in humans was 25.62% (95%CI 22.11-29.12). Age in years (PR = 1.01 95%CI 1.01-1.02) and male sex (PR = 1.65 95%CI 1.43-1.90) were risk markers for rickettsial seropositivity. Working outdoors (PR = 1.20 95%CI 1.02-1.41), deforestation and forest fragmentation for agriculture use (PR = 1.75 95%CI 1.51-2.02), opossum in peridomiciliary area (PR = 1.56 95%CI 1.37-1.79) and a high proportion of seropositive domestic animals in the home (PR20-40% vs 40% vs <20% = 3.14 95%CI 2.43-4.04) were associated with rickettsial seropositivity in humans. This study showed the presence of Rickettsia antibodies in human populations and domestic animals. In addition, different species of rickettsiae were detected in ticks collected from humans and animals. Our results highlighted the role of domestic animals as sentinels of rickettsial infection to identify areas at risk of transmission, and the importance of preventive measures aimed at curtailing deforestation and the fragmentation of forests as a way of reducing the risk of transmission of emergent and re-emergent pathogens

Integrative DNA Methylation and Gene Expression Analyses Identify DNA Packaging and Epigenetic Regulatory Genes Associated with Low Motility Sperm

In previous studies using candidate gene approaches, low sperm count (oligospermia) has been associated with altered sperm mRNA content and DNA methylation in both imprinted and non-imprinted genes. We performed a genome-wide analysis of sperm DNA methylation and mRNA content to test for associations with sperm function. (NCBI 1788). There was a trend among altered expression of these epigenetic regulatory genes and RPMM DNA methylation class.Using integrative genome-wide approaches we identified CpG methylation profiles and mRNA alterations associated with low sperm motility

Genetic Data Showing Evolutionary Links between Leishmania and Endotrypanum

Striking similarities at the morphological, molecular and biological levels exist between many trypanosomatids isolated from sylvatic insects and/or vertebrate reservoir hosts that make the identification of medically important parasites demanding. Some molecular data have pointed to the relationship between some Leishmania species and Endotrypanum, which has an important epidemiological significance and can be helpful to understand the evolution of those parasites. In this study, we have demonstrated a close genetic relationship between Endotrypanum and two new leishmanial species, L. (V.) colombiensis and L. (V.) equatorensis. We have used (a) numerical zymotaxonomy and (b) the variability of the internal transcribed spacers of the rRNA genes to examine relationships in this group. The evolutionary trees obtained revealed high genetic similarity between L. (V.) colombiensis, L. (V.) equatorensis and Endotrypanum, forming a tight cluster of parasites. Based on further results of (c) minicircle kDNA heterogeneity analysis and (d) measurement of the sialidase activity these parasites were also grouped together

Transcriptional and genomic parallels between the monoxenous parasite Herpetomonas muscarum and Leishmania

Trypanosomatid parasites are causative agents of important human and animal diseases such as sleeping sickness and leishmaniasis. Most trypanosomatids are transmitted to their mammalian hosts by insects, often belonging to Diptera (or true flies). These are called dixenous trypanosomatids since they infect two different hosts, in contrast to those that infect just insects (monoxenous). However, it is still unclear whether dixenous and monoxenous trypanosomatids interact similarly with their insect host, as fly-monoxenous trypanosomatid interaction systems are rarely reported and under-studied–despite being common in nature. Here we present the genome of monoxenous trypanosomatid Herpetomonas muscarum and discuss its transcriptome during in vitro culture and during infection of its natural insect host Drosophila melanogaster. The H. muscarum genome is broadly syntenic with that of human parasite Leishmania major. We also found strong similarities between the H. muscarum transcriptome during fruit fly infection, and those of Leishmania during sand fly infections. Overall this suggests Drosophila-Herpetomonas is a suitable model for less accessible insect-trypanosomatid host-parasite systems such as sand fly-Leishmania

Immunity and vaccine development efforts against Trypanosoma cruzi

Artículo de revisión especializadoTrypanosoma cruzi (T. cruzi) is the causative agent for Chagas disease (CD). There is a critical lack of methods for prevention of infection or treatment of acute infection and chronic disease. Studies in experimental models have suggested that the protective immunity against T. cruzi infection requires the elicitation of Th1 cytokines, lytic antibodies and the concerted activities of macrophages, T helper cells, and cytotoxic T lymphocytes (CTLs). In this review, we summarize the research efforts in vaccine development to date and the challenges faced in achieving an efficient prophylactic or therapeutic vaccine against human CD.UTM