Iron metabolism and its relationship to anemia and immune system in Trypanosoma evansi infected rats

Trypanosoma sp. infection in Boa constrictor snakes: morphological, hematological, clinical biochemistry, molecular, and phylogenetic characteristics

There are few reports of Trypanosoma in snakes, as well as little information about its pathogenicity in these animals. Thus, the present study aimed to characterize Trypanosoma found in Boa constrictor snakes, to verify the influence of the parasitism on hematological and clinical biochemistry parameters, and to perform a phylogenetic study of the isolates. Blood samples from sixty-one boas were analyzed for the presence of trypanosomatids and by hematological and clinical biochemistry assays. The flagellates that were found in this analysis were used for cell culture, morphometry, and molecular analysis. Later, molecular typing phylogenetic studies were performed. Nine positive animals (14.75%) were identified by microscopy analysis. The hematological results showed that parasitized animals presented significantly lower levels of packed cell volume, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin. In the leukogram, eosinophils and heterophils counts were higher in parasitized animals. Considering the molecular analyses, the isolates presented a higher identity of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the 18S small subunit ribosomal RNA (SSU rRNA) gene fragments with Trypanosoma serpentis. The phylogenetic tree, using the GAPDH, clustered all isolates with T. serpentis and Trypanosoma cascavelli. This is the first description of T. serpentis parasitizing boas and of the clinical changes caused by trypanosomatid infection in snakes.

Reactive oxygen species, glutathione, and vitamin E concentrations in dogs with hemolytic or nonhemolytic anemia

BACKGROUND

Red blood cells (RBC) are uniquely susceptible to oxidative injury. Oxidative stress is both a cause for, and effect, of anemia in people but this has been minimally documented in dogs.

OBJECTIVE

To describe direct and indirect markers of oxidative stress in anemic dogs.

HYPOTHESIS

Anemic dogs will have oxidative stress when compared to healthy dogs.

ANIMALS

Forty-seven dogs with anemia (10 with hemolytic anemia) and 70 healthy control dogs.

METHODS

Prospective, cross-sectional study. Anemic dogs were identified from the patient population, and medical records were reviewed to classify the anemia as hemolytic or nonhemolytic. Flow cytometry was used to detect reactive oxygen species (ROS) in erythrocyte isolates. Reduced glutathione (GSH) concentrations were measured in both plasma and hemolysate samples, and vitamin E was measured in serum.

RESULTS

Anemic dogs (both hemolytic and nonhemolytic) had significantly lower median RBC hemolysate GSH concentrations (3.1 μM [0.4-30.8]) when compared to healthy dogs (7.0 μM [0.5-29.7]; P = .03). Dogs with hemolytic anemia had significantly higher median plasma GSH (7.6 μM [0.4-17.8]) when compared to dogs with nonhemolytic anemia (1.6 μM [0.01-7.1]; P = .04) and healthy dogs (2.8 μM [0.1-29.9]; P < .0001). Reactive oxygen species were detectable in all samples, but there was no difference in ROS or vitamin E between groups.

CONCLUSIONS AND CLINICAL IMPORTANCE

Oxidative stress is present in anemic dogs. Derangements in biomarkers of oxidative stress are different in dogs with hemolytic anemia and nonhemolytic anemia.

Impacts of Time-Fed Concentrate-Based Diets on Plasma Metabolites, Rumen Histology, and mRNA Expression of Hepatic Enzymes of Wethers

Simple Summary

In modern ruminant meat production systems, wethers and steers are commonly fed diets containing 80% grain, or more. These diets are commonly fed to increase fat deposition in meat-producing ruminants. However, when wethers and steers are not appropriately transitioned to grain-based diets, they can experience metabolic and inflammatory conditions that negatively affect health and production. It is still unclear how meat-producing ruminants adapt to grain-based diets over time. This study evaluated the effects of an abrupt dietary change, from 80% forage to 80% grain, on rumen, plasma, and liver metabolism in growing wethers and monitored their ability to adapt over time. The results of the study suggest that wethers fed an 80% grain diet adapt over time by altering the expression of key enzymes involved in the systemic inflammation, iron metabolism, and cholesterol and glucose synthesis. This study provides novel insight into the physiology of fattening ruminants that have been abruptly fed grain-based diets and highlights the fact that meat-producing animals can be fed grain-based diets to meet increasing human meat requirements.

Abstract

Transition to grain increases inflammation and causes parakeratosis, which can decrease growth performance in fattening animals. It is unknown if ruminants adapt to these inflammatory responses over time. In a three-phase, 49-day experiment, all wethers (n = 13, BW = 50.6 ± 4.7 kg; 4.9 ± 0.3 months of age) were fed an 80% forage diet during P1(day 0 to 21). On day 21, 4 wethers were slaughtered to obtain baseline liver and rumen tissue. During P2 (day 22 to 25), the remaining wethers were fed an 80% concentrate diet. Four wethers were slaughtered on day 25 to obtain P2 liver and rumen tissue. During P3 (day 22 to 49), the remaining five wethers were fed 80% concentrate diets and were slaughtered on day 49 to obtain P3 liver and rumen tissue. Rumen parakeratosis was greater (p ≤ 0.02) in wethers sampled in P2 and P3 when compared to those sampled in P1. Among positive acute phase reactants, expression of serum α-amyloid (SAA) and haptoglobin (HPT) tended (p ≤ 0.12) to be 6- and 10-fold greater, respectively, in wethers sampled in P2 compared to wethers sampled in P1; however, SAA and HPT expression was not different between wethers sampled in P3 and P1. Plasma glucose and β-hydroxybutyric acid (BHBA) increased (p ≤ 0.03) in wethers sampled in both P2 and P3 compared to the wethers sampled in P1, while total protein and cholesterol decreased (p ≤ 0.06) only in wethers sampled from P2 compared to those sampled in P1. Hepatic acute phase responses suggest that the wethers adapted to an 80% concentrate diet over time.

Salivarian Trypanosomosis: A Review of Parasites Involved, Their Global Distribution and Their Interaction With the Innate and Adaptive Mammalian Host Immune System

Salivarian trypanosomes are single cell extracellular parasites that cause infections in a wide range of hosts. Most pathogenic infections worldwide are caused by one of four major species of trypanosomes including (i) Trypanosoma brucei and the human infective subspecies T. b. gambiense and T. b. rhodesiense, (ii) Trypanosoma evansi and T. equiperdum, (iii) Trypanosoma congolense and (iv) Trypanosoma vivax. Infections with these parasites are marked by excessive immune dysfunction and immunopathology, both related to prolonged inflammatory host immune responses. Here we review the classification and global distribution of these parasites, highlight the adaptation of human infective trypanosomes that allow them to survive innate defense molecules unique to man, gorilla, and baboon serum and refer to the discovery of sexual reproduction of trypanosomes in the tsetse vector. With respect to the immunology of mammalian host-parasite interactions, the review highlights recent findings with respect to the B cell destruction capacity of trypanosomes and the role of T cells in the governance of infection control. Understanding infection-associated dysfunction and regulation of both these immune compartments is crucial to explain the continued failures of anti-trypanosome vaccine developments as well as the lack of any field-applicable vaccine based anti-trypanosomosis intervention strategy. Finally, the link between infection-associated inflammation and trypanosomosis induced anemia is covered in the context of both livestock and human infections.

Outcomes of Trypanosoma cruzi and Trypanosoma evansi infections on health of Southern coati (Nasua nasua), crab-eating fox (Cerdocyon thous), and ocelot (Leopardus pardalis) in the Brazilian Pantanal

The occurrence of Trypanosoma spp. in wild carnivore populations has been intensively investigated during the last decades. However, the impact of these parasites on the health of free-living infected animals has been largely neglected. The Pantanal biome is the world’s largest seasonal wetland, harboring a great diversity of species and habitats. This includes 174 species of mammals, of which 20 belong to the order Carnivora. The present study aimed to investigate the effect of Trypanosoma evansi and Trypanosoma cruzi infections and coinfections on the health of the most abundant carnivores in the Pantanal: coati (Nasua nasua), crab-eating fox (Cerdocyon thous), and ocelot (Leopardus pardalis). We captured 39 coatis, 48 crab-eating foxes, and 19 ocelots. Diagnostic tests showed T. cruzi infection in 7 crab-eating foxes and 5 coatis. Additionally, 7 crab-eating foxes, 10 coatis, and 12 ocelots were positive for T. evansi. We observed coinfections in 9 crab-eating foxes, 8 coatis, and 2 ocelots. This is the first report of T. evansi and T. cruzi infection on the health of free-living ocelots and crab-eating foxes. We showed that single T. evansi or T. cruzi infection, as well as coinfection, caused some degree of anemia in all animals, as well as an indirect negative effect on body condition in coatis and crab-eating foxes via anemia indicators and immune investment, respectively. Furthermore, the vigorous immune investment observed in sampled coatis, crab-eating foxes and ocelots infected by T. evansi, T. cruzi and coinfected can be highly harmful to their health. Overall, our results indicate that single and combined infection with T. evansi and T. cruzi represent a severe risk to the health of wild carnivores in the Pantanal region.

Possible Differences in the Effects of Trypanosoma cruzi on Blood Cells and Serum Protein of Two Wildlife Reservoirs

A key step in the dynamics of vector-borne diseases is the role of seasonality. Trypanosoma cruzi is a protozoan that causes Chagas disease. Some wild mammals are considered natural hosts, yet not all mammals show the same response to infection. We explored the effect of T. cruzi on blood parameters in two mammal carnivores, coati (Nasua narica) and raccoon (Procyon lotor), that were naturally infected in summer and winter seasons. The study was carried out in the Zoological Park "Parque Museo de la Venta," in Southeastern Mexico. Blood samples were collected in summer and winter from 2010 to 2013. Parasite infection was assessed by PCR from whole blood, and a complete hemogram was determined by traditional manual methods. We found that both species had the same T. cruzi I lineage. For coatis, mean corpuscular volume, mean corpuscular hemoglobin, and monocytes were dependent of season, while eosinophils and plasma proteins were significantly different, but with no season effect. For raccoon, erythrocytes, mean corpuscular volume, mean corpuscular hemoglobin, and monocytes were dependent of season. These results and a previous study that indicated interspecific differences in parasitemia in both species suggest that raccoon is a better reservoir than coati. Such a different interspecific response implies that animals do not contribute equally to maintain T. cruzi parasites in the ecosystem. Such inequality differs according to season.