Pathological, morphological, and molecular characterization of the infection by Brachycladium goliath in humpback whale Megaptera novaeangliae.

The humpback whale (Megaptera novaeangliae) is a cosmopolitan migratory, seasonal mysticete that frequents the Brazilian coast. Strands of specimens may occur during the migratory stay in the country. In 2021 and 2022, three live humpback whales stranded on the coast of Rio Grande do Sul and Santa Catarina states in southern Brazil. After euthanasia, specimens were necropsied, and organs were thoroughly examined for lesions. Grossly, in all three cases, the liver exhibited multifocal, irregular, firm, white areas on the hepatic capsule, which extended into the parenchyma. On the cut surface, the livers were yellow to pale brown with orangish to greenish areas, the bile ducts were prominent, thickened, and severely dilated, and leaf-shaped flukes were found inside of them. Additionally, one case showed moderate atrophy of the right hepatic lobe. The histological findings included dilation of bile ducts, hyperplasia of the bile duct epithelium, marked inflammatory infiltration of lymphocytes, plasma cells, and eosinophils, and portal fibrosis. The parasite Brachycladium goliath was both morphologically and molecularly identified based on diagnostic key for trematodes and the original description of the species, and the amplification and sequencing of the ITS-2 region, respectively. Even though hepatic injury was not the primary cause of stranding, it may have contributed to the debilitation of the whales. To the authors' knowledge, this is the first study that reports M. novaeangliae as a definitive host of B. goliath and that describes the lesions caused by the parasite in cetaceans.

Septicemic salmonellosis in suckling piglets resulting from improper intramuscular administration of an oral vaccine.

We describe an unusual outbreak of mortality in suckling piglets following the misadministration of an oral vaccine against Salmonella Typhimurium and Salmonella Choleraesuis. Within 3-48 h of vaccination of a batch of ~700 piglets, ~300 developed marked swelling in the dorsal neck region, respiratory distress, fever, recumbency, and apathy. In total, ~100 died, and 4 were submitted for autopsy. Gross and microscopic lesions consisted of focally extensive areas of purple discoloration in the skin of the cervical region, associated with edema and hemorrhage in the subcutis and muscles. Additionally, there was interstitial pneumonia with marked interlobular edema and mild fibrinous pleuritis. Aerobic bacterial culture identified Salmonella Typhimurium (3 cases) and Salmonella Choleraesuis (1 case) in samples of skeletal muscle and lung and from pleural swab samples. Marked immunostaining against Salmonella spp. was observed in the skeletal muscle of the cervical region, as well as in blood vessels and macrophages from the lung, liver, spleen, and kidney. We concluded that inappropriate intramuscular administration of an oral vaccine against Salmonella resulted in septicemia and death in a batch of piglets.

Auricular and laryngeal chondritis in nursery and finishing pigs.

This work aimed to characterize the clinic-pathological presentation of an outbreak of auricular and laryngeal chondritis in pigs. Visits were made to pig farms, where the clinical history was obtained, and clinical and postmortem examinations were performed. In those farms, 3% to 4% of pigs presented otohematomas, which started in the nursery and extended to the finishing phase. Moreover, some finishing pigs presented with respiratory distress, initially characterized as inspiratory dyspnea, associated by an uncommon respiratory stridor and culminating in death. Grossly, nursery piglets had enlarged ears, and on the cut surface, the cartilage was fragmented and associated with blood clots. In the finishing phase, in addition to auricular lesions, the epiglottis and arytenoid cartilages were thickened and distorted, which partially occluded the lumen. Microscopically, the laryngeal and auricular cartilages were fragmented, displayed a loss of matrix basophilia, and were surrounded by lymphohistiocytic inflammatory infiltrate, with occasional multinucleated giant cells and fibrosis. The lesions exclusively affected elastic cartilages. The disease in finishing pigs led to increased mortality and was a differential diagnosis to respiratory challenges. It was not possible to determine the factor that triggered this condition; however, a nutritional association is suspected. To the authors' knowledge, this is the first report of primary auricular and laryngeal chondritis in pigs.

Main Causes of Death in Piglets from Different Brazilian Nursery Farms Based on Clinical, Microbiological, and Pathological Aspects.

Necropsies can reveal herd problems or comorbidities that can lead to management corrections, improvements in animal performance, and better decision making. Furthermore, the pattern and causes of mortality might differ when different systems are evaluated. The present study was conducted to establish the main causes of death in nursery pigs from different systems in Brazil, as well as the clinical, microbiological, and pathological aspects of these mortalities. Eighteen nurseries were analyzed (a total of 120,243 housed piglets), and 557 necropsies were performed. Streptococcus suis infection was the most prevalent cause of death (21.2%), followed by bacterial polyserositis (16.7%), chronic atrophic enteritis (13.5%), salmonellosis (8.8%), pneumonia (8.6%), and colibacillosis (6.1%). The increase in mortality rate in individual nurseries and, consequently, in the diagnoses was commonly associated with disease outbreaks. Infectious diseases constituted the largest portion of the diagnoses, making a great opportunity for improving production rates in herds. Moreover, the extensive range of observed diagnoses highlights the importance of conducting preliminary diagnostic investigations based on necropsy to determine the causes of death. This approach allows for the direction of complementary tests, which can diagnose agents with greater specificity. As a result, this allows for the implementation of more effective prevention and control strategies.

Anatomopathological characterization of branchial cysts in slaughtered pigs.

Branchial cysts are a congenital anomaly in humans and other animal species. In this study, twenty commercially bred slaughtered pigs ranging from 120 to 150 days of age, sourced from different farms and lots, were found to have cysts in the oropharyngeal region at meat inspection despite the absence of clinical signs. Two cysts were selected for histopathological examination. The first cyst was surrounded by fibrous connective tissue and lined by a simple single cell layer of epithelium. The second cyst comprised a squamous pseudostratified to simple stratified epithelium, accompanied by a mild inflammatory infiltrate. This cyst was also surrounded by fibrous connective tissue and glands. The pathological diagnosis of branchial cysts in slaughtered pigs was established on the basis of their anatomical location and gross and microscopic findings.

Fatal Simplexvirus humanalpha1 infection in howler-monkeys (Alouatta sp.) under human care: Clinical, molecular, and pathological findings.

BACKGROUND: Simplexvirus humanalpha1 (HuAHV-1) are common anthropozoonosis reported in marmosets but rare in howler monkeys (Alouatta sp.). METHODS: Necropsy of two brown-howler monkeys (A. caraya) and one red-howler monkey (A. guariba clamitans) from different zoo collections were performed. Fragments of all organs were examined through microscopy. Samples were submitted to IHC for Simplexvirus humanalpha 2 (HuAHV-2) [sin. Herpesvirus simplex type 2] and PCR. RESULTS: Grossly, only the A. guariba showed liver lesions characterized by multifocal, pinpoint white areas corresponding microscopically as random necrotizing herpetic hepatitis and ulcerative glossitis. Both A. caraya showed necrotizing meningoencephalitis with Cowdry A-type body inclusions within neurons and astrocytes. Immunolabeling for HuAHV-1/2 was observed in the tongue, liver, and brain. HuAHV-1 was confirmed in all samples by PCR, Sanger sequencing, and phylogenetic analyses. CONCLUSION: Necrotizing meningoencephalitis was appreciated in 2/3 of animals, and it is associated with neurologic signs. Along with ulcerative glossitis, a hallmark lesion in marmosets, it was present in one animal. Regarding herpetic hepatitis, it is not frequent in monkeys and occurs mainly in immunocompromised animals. HuAHV-1 infection was confirmed corroborating with a human source. This is the second report on captive black-howler monkeys and the first gross, histologic, immunohistochemical, and molecular description of herpetic hepatitis and ulcerative glossitis in red-howler monkeys (A. guariba).

Acute necrotic hepatotoxicity caused by Melanthera latifolia (Asteraceae) in cattle.

This study aims to report a spontaneous and experimental intoxication in cattle by Melanthera latifolia (Asteraceae) for the first time, and to describe its epidemiological, clinical, and pathological findings. An outbreak of acute toxic hepatopathy in cattle occurred from December of 2021 to January of 2022 in a beef cattle farm from Rio Grande do Sul state, Southern Brazil, and resulted in 94 deaths from a herd of 430 animals. At necropsy, lesions consisted of enhanced lobular pattern of the liver, transmural gallbladder edema, and hemorrhages on the surface of multiple organs. The main microscopic lesion was marked hepatocellular necrosis in the centrilobular region associated with hemorrhage and infiltration of neutrophils. During the outbreak, multiple specimens of M. latifolia were noted in the paddocks where affected cattle were grazing and many showed signs of consumption. No other known acute hepatotoxic plants were found. Two 12-month-old steers were experimentally intoxicated with a single oral dose of the fresh plant (flowers, leaves, and less fibrous stalks). One bovine ingested a dose of 10 g/kg and was euthanized after 48 h, and the other ingested 15 g/kg and was euthanized 17 h later. Clinical signs, macroscopic, and microscopic lesions in both animals were similar to those observed in the spontaneous cases. Thus, this study demonstrates that M. latifolia was the cause of the outbreak of acute toxic hepatopathy with significant mortality in cattle. M. latifolia nor any plant of the genus Melantherahad ever been reported as toxic.

Differential proteomics of Zika virus (ZIKV) infection reveals molecular changes potentially involved in immune system evasion by a Brazilian strain of ZIKV.

Zika virus (ZIKV) is an arbovirus that was responsible for multiple outbreaks from 2007 to 2015. It has been linked to cases of microcephaly in Brazil in 2015, among other neurological disorders. Differences among strains might be the reason for different clinical outcomes of infection. To evaluate this hypothesis, we performed a comparative proteomic analysis of Vero cells infected with the African strain MR766 (ZIKVAFR) and the Brazilian strain 17 SM (ZIKVBR). A total of 550 proteins were identified as differentially expressed in ZIKVAFR- or ZIKVBR-infected cells compared to the control. The main findings included upregulation of immune system pathways (neutrophil degranulation and adaptive/innate immune system) and potential activation of immune-system-related pathways by ZIKVAFR (mTOR, JAK-STAT, NF-κB, and others) compared with the ZIKVBR/control. In addition, phagocytosis by macrophages and engulfment of leukocytes were activated in ZIKVAFR infection. An in vivo analysis using an immunocompetent C57BL/6N mouse model identified interstitial pneumonia with neutrophil infiltration in the lungs only in mice infected with ZIKVBR at 48 hours postinfection, with a significant amount of virus detected. Likewise, only animals infected with ZIKVBR had viral material in the cytoplasm of lung macrophages. These results suggest that activation of the immune system by ZIKVAFR infection may lead to faster viral clearance by immune cells.

Acute Oral Chromium Exposure Resulting in Ulcerative Gastritis and Perforated Ulcers in Swine.

Heavy metal poisoning poses a challenge in diagnostic practices and environmental safety. This study describes the epidemiological, clinical, and pathological aspects of a chromium (Cr) poisoning outbreak in growing/finishing pigs housed in pens with bedding of pine wood shavings containing Cr. A visit to the affected farm was conducted. Epidemiological data were collected, and necropsy and histopathological examinations and heavy metal quantifications were performed. Up to 30% of the animals from the affected pens displayed clinical signs 48 h after housing, characterized by apathy, rigid gait, distended abdomen, pain to abdominal palpation, fever, vomiting, and skin cyanosis. The lethality rate reached 76.6%. Main postmortem findings consisted of ulcerative gastritis with perforation of the glandular stomach in all necropsied swine. Heavy metal analysis revealed a higher concentration of Cr in the bedding of the affected pens, along with elevated levels of Cr in the livers of the affected swine. Given that Cr is a known cause of poisoning in humans (with acute oral exposure resulting in corrosive lesions in the gastrointestinal tract), this study marks the first diagnosis of acute oral natural Cr poisoning in animals. This diagnosis was established through the association of epidemiological, pathological, and heavy metal quantification data.

Nutritional chondrodysplasia in cattle in Brazil.

In this work, we investigated cases of birth of calves with congenital defects in a farm in Southern Brazil. Only calves born from heifers were affected, and the disease occurred in both crossbred and purebred calves. Three necropsies were performed, tissues were collected for histopathology, and samples of liver of calves, blood serum, and food provided for cows and heifers were collected to quantify the levels of the minerals: manganese, copper, and zinc. The calves were born weak, with disproportionate dwarfism, limb deformities, and enlarged joints. Heads were shortened and domed. Long bones had a shortened diaphysis and a normal-sized epiphysis, when compared to the control. In one of the cases, there were white-yellowish lines on the metaphyseal surface of the epiphyseal plate. Histopathology of growth plates revealed premature closure, disarrangement of chondrocyte columns, and collapse of primary spongiosa. These findings supported a diagnosis of chondrodysplasia. Liver manganese levels were under the reference values in the three calves. Food analysis revealed insufficient levels of manganese in the diet of heifers, especially in sorghum silage, which was provided as the main source of food for the category in some periods. Approximately 6 months after the diet was changed, the problem ceased and only normal calves continued to be born. Our findings allowed to conclude the diagnosis of chondrodysplasia of nutritional origin and reinforce the thesis that manganese is the mineral deficient in these cases.

Pathogenetic effects of feed intake containing of fumonisin (Fusarium verticillioides) in early broiler chicks and consequences on weight gain.

Fusarium verticillioides is often responsible for contamination of poultry feed with the mycotoxin fumonisin. The objective of the study was to determine whether fumonisin-contaminated feed in the early phase of broiler chicks causes oxidative imbalances and interferes with weight gain. One-day-old male Cobb 500 broiler chicks (n = 80) were divided into four treatments of 20 birds each, all of which were fed basal feed until the 11th day of age. From day 12, some birds were challenged with fumonisin in the feed: Control (T0) continued receiving the basal ration; treatments T1, T2, and T3 were given feed experimentally contaminated with fumonisin at concentrations of 2.5 ppm, 5 ppm and 10 ppm, respectively. After the 5th (day 17) and 10th (day 21) days, ten birds from each treatment were euthanized for blood and tissue collection to measure histopathological, biochemical and oxidative stress markers. All animals were weighed individually at the beginning of the experiment (day 12), and at 17 and 21 days of age. Birds that ingested 10 ppm of fumonisin (T3) had lower (P < 0.05) weight gain compared to those in T0. At 21 days, the body weights of the T1, T2 and T3 chicks were 1.3%, 8.97% and 18.7% lower, respectively, than those of T0. No histological lesions in the livers were observed for any treatment; however, higher levels of reactive oxygen species (ROS: day 21) and lipoperoxidation (LPO: days 17 and 21) were observed, associated with lower liver activity of the enzymes superoxide dismutase (SOD: day 21), glutathione peroxidase (GPx: day 17 and 21) and glutathione S-transferase (GST: day 21) when birds consumed 5 or 10 ppm of fumonisin. In serum, LPO levels and SOD and GPx activities were lower for groups consuming high doses of fumonisin in the diet (T2 and T3); ROS levels and GST activity were higher in these birds. Birds that consumed fumonisin-containing diets had lower levels of alanine aminotransferase, total protein and albumin (T3); as well as lower serum glucose levels (days 17 and 21), uric acid and triglycerides (day 21) in T3 than in T0. At 21 days, there were smaller crypt sizes and intestinal villi in birds that consumed high levels of fumonisin. These results suggest that fumonisin (10 ppm) in chick diet causes hepatic oxidative stress and impairs intestinal health, consequently negatively affecting weight gain.

Effects of glycerol monolaurate on growth and physiology of chicks consuming diet containing fumonisin.

Glycerol monolaurate (GML) is composed of lauric acid and glycerol. Research has shown that such organic acids can minimize negative effects caused by mycotoxins. Therefore, the objective of this study was to determine whether adding GML (free or encapsulated) to chick feed minimizes the effects of natural contamination by fumonisin (Fusarium verticillioides), evaluating parameters such as biochemistry, antioxidant properties, histological analysis and chick growth. Were weighed 84 chicks of the Cobb 500 strain and randomly distributed them into six groups of two replicates each (n = 14). The F group consumed feed containing fumonisin (levels 400 ppb), with no performance enhancer; F + ZB- feed with fumonisin (levels 400 ppb) + zinc bacitracin; F + GLM100 - feed with fumonisin (levels 400 ppb) + 100 mg of GML/kg of feed; F + NGLM4 - feed with fumonisin (levels 400 ppb) + 4 mg GML/kg in nanocapsules added to the feed; F + NGLM8 - fumonisin feed (levels 400 ppb) + 8 mg GML/kg in nanocapsules in the feed; and F0 - fumonisin-free feed (negative control) + zinc bacitracin. The body weights of birds fed with feed fumonisin-contaminated feed (F, F + ZB, F + GLM100, F + NGLM4 and F + NGLM8) were significantly lower (P < 0.05) than those of the negative control (F0), despite the use of GML (free and nanoencapsulated). Serum levels of triglycerides, globulins and cholesterol were significantly lower in the F0 group than in the other groups (P < 0.05), except for the F + NGLM8 group. Significantly greater levels of lipid peroxidation were observed in livers in the groups that consumed fumonisin than in the control group (F0) (P < 0.05). Serum levels of reactive oxygen species were significantly lower in groups F + NGLM8 and F0 than in the other treatments (P < 0.05). Superoxide dismutase activity was significantly greater in groups F + NGLM8 and F0 than in groups F, F + ZB and F + NGLM4. Hepatic catalase activity was significantly lower in birds that consumed contaminated feed (F, F + ZB, F + GLM100, F + NGLM4 and F + NGLM8) than in the control group (F0). Greater hepatic glutathione S-transferase activity was observed in the F + NGLM8 group than in the F0 group. Despite changes in cellular lesions in the liver, no histological changes were observed in the liver or intestines, even though visually there was yellowing of the liver. Taken together, the data suggest that free or nano-encapsulated GML did not minimize oxidative stress caused by fumonisin, and consequently, these birds had less weight gain.

Experimental infection by Neospora caninum in gerbil reduces activity of enzymes involved in energy metabolism.

Neospora caninum is a protozoan that has tropism for the central nervous system. The aim of this study was to determine whether experimental infection of gerbils would interfere with activity of enzymes associated with energy metabolism. We randomized 20 gerbils into two groups (ten animals per group): the control group (healthy animals; uninfected) and the infected group (experimentally infected with dose 7.8 × 102 tachyzoites of N. caninum per gerbil). On day six and twelve post-infection (PI), brain and spleen tissues were collected for biochemical and histopathological analyses. No histopathological lesions were observed in the brains of infected animals; however, inflammatory infiltrates were found in the spleen. Significantly greater levels of reactive oxygen species (ROS) were observed in the brain and spleen of infected gerbils than in the control group at 12 days PI. Cytosolic creatine kinase (CK-CYT), mitochondrial creatine kinase (CK-MIT), and pyruvate kinase (PK) activities were lower in the brains of infected gerbils than in those of the control group on day 12 PI. There was significantly less CK-CYT activity in the spleens of infected gerbils on day 6 and 12 PI. Finally, there was significantly less sodium-potassium ion pump (Na+/K+ ATPase) activity in the brains and spleens of infected gerbils on day 12 PI. These data suggest that experimental infection with N. caninum interfered with energy metabolism associated with ATP homeostasis in the brain and spleen, directly or indirectly, apparently mediated by ROS overproduction, contributing to inhibition of Na+/K+ ATPase activity.

Combination of herbal components (curcumin, carvacrol, thymol, cinnamaldehyde) in broiler chicken feed: Impacts on response parameters, performance, fatty acid profiles, meat quality and control of coccidia and bacteria.

The objective of this study was to determine whether curcumin and a commercial microencapsulated phytogenic supplement containing thymol, cinnamaldehyde and carvacrol in broiler chicken feed would improve health and meat quality (fatty acid profile), as well as to determine the coccidiostatic and bactericidal potential of the additives. The broiler chickens were divided into five groups: NC - negative control feed; PC - positive control; CU - with 50 mg/kg of curcumin, PHY - 100 mg/kg phytogenic; and PHY + CU, a combination of both additives at 50 mg/kg (curcumin) and 100 mg/kg (phytogenic). We observed significantly higher levels of total proteins associated with increased circulating globulins, as well as lower levels of uric acid, cholesterol and triglycerides in the PHY + CU group than in the NC. There were significantly fewer oocysts in birds supplemented with additives in the NC group on day 21; on day 35, the NC, PHY and PHY + CU groups had significantly lower counts than the PC and CU groups; however, at 44 days, the lowest counts were in PC group. The bacterial counts were significantly lower on day 21 in all groups that received additives than those of the control group; however, at 44 days, the bacterial and Escherichia coli counts in these groups were significantly higher than those of the control. Curcumin with or without phytogenic agent improved meat quality, with increased antioxidant levels and reduction of lipid peroxidation. There were significantly lower total saturated fatty acid levels and significantly greater monounsaturated/polyunsaturated fatty acid levels in broilers that consumed additives individually and in combination. The combination of additives significantly increased the crypt/villus ratio, a marker of improved intestinal health and performance. Additives potentiated their individual effects, suggesting they can replace conventional growth promoters without compromising health, intestinal mucosa or meat quality.

Impact of Escherichia coli infection in broiler breeder chicks: The effect of oxidative stress on weight gain.

The aim of this study was to determine whether oxidative stress occurs in Escherichia coli-infected broiler breeder chicks, as well as the impact of this infection on bird growth. Twenty birds, 25-day-old female birds were divided into two groups (n = 10 per group): an intraperitoneally-infected group (1 mL containing 1.5 × 108 CFU of E. coli) and a control group that received 1 mL of culture medium (uninfected birds). Birds were weighed individually at the beginning and at the end of the experiment, and samples were collected on days 0, 5 and 10 post-infection (PI). No clinical signs were observed throughout the experimental period; nevertheless, on day 10 PI, there was lower growth and weight gain in infected birds than in the control group. The infected birds showed pericarditis and liver congestion, as well as moderate periportal inflammatory infiltrates with predominance of neutrophils. Significantly higher numbers of total leukocytes, lymphocytes, heterophils and monocytes were observed in the infected group on days 5 and 10 PI, as well as significantly higher total protein and globulin levels; albumin values significantly decreased over the same period. Levels of serum oxidative biomarkers (lipid peroxidation (TBARS) and free radicals (ROS)) were significantly higher at 10 PI, as was glutathione S-transferase (GST) activity during the same period. Hepatic ROS and protein thiol levels were significantly higher in E. coli-infected birds, as well as activities of the antioxidant enzymes catalase, superoxide dismutase. In the spleen, only GST activity was significantly higher for the infected group, unlike the brain, where SOD activity, ROS and non-protein thiol levels were significantly higher in infected birds than in the control group. These data suggested that colibacillosis causes oxidative stress in broiler breeder chicks, negatively affecting their weight gain.

Cholinesterase as an inflammatory marker of subclinical infection of dairy cows infected by Neospora caninum and risk factors for disease.

The aim of this study was to evaluate the seroprevalence of Neospora caninum in dairy cows, as well as to verify the risk factors for N. caninum infection and inflammatory response in dairy cows. Using the indirect immunofluorescence reaction, the seroprevalence of neosporosis was determined to be 32.82%. Based on regression analysis, the presence of dogs at a farm increased the probability of a cow testing positive for N. caninum (OR = 20.01 [5.21-123.12]). These data suggest that N. caninum has a relevant prevalence in dairy cows of the Microregion of Rio do Sul (Brazil), with elevated frequencies of anti-N. caninum IgG. The data also suggest that the parasite is widely distributed in dairy herds of the micro-region, because 94.4% of properties screened had at least one seropositive animal. The principal risk factors for disease maintenance in herds may be considered the presence of dogs and absence of a diagnostic test when introducing new animals. Blood from these cows was used to measure variables related to the inflammatory response. Serum cholinesterase activity, as well as serum levels of globulins and C-reactive protein were higher in seropositive to N. caninum than in seronegative cows. Furthermore, the infection by parasite causes an intense inflammatory process, contributing to disease pathophysiology.

Lipid peroxidation and protein oxidation in broiler breast fillets with white striping myopathy.

The aim of this study was to evaluate whether broiler breast fillets with severe white striping (WS) had elevated levels of lipid peroxidation and protein oxidation, as well as antioxidant responses. A total of 45 breast muscles from broiler chickens were divided into three groups (n = 15): normal, moderate (stripes <1 mm) and severe (stripes >1 mm). Chicken breasts with severe WS showed muscular cells with small areas and diameters (p < 0.05), as well as the presence of inflammatory cells. Higher percentages of moisture content, fat, collagen, and smaller protein content than did WS breast samples compared control. Breast samples with moderate and severe degrees of WS had higher reactive oxygen species levels and advanced oxidation protein products than did the control group, and animals with severe WS had higher lipid peroxidation levels. The activities of glutathione peroxidase and glutathione S-transferase were higher (p < 0.0001) in animals with moderate WS than those in the control. PRACTICAL APPLICATIONS: White striping myopathy in broiler breast fillets is characterized by the presence of parallel white stripes in the same direction as the muscular fiber, commonly occurring in the pectoralis major muscle. The results showed that chicken breasts with WS demonstrated imbalances of antioxidant/oxidant status, characterizing increases of lipid peroxidation and protein oxidation in muscle. This situation does not prevent the consumption of the meat, but negatively affects its quality.

Intestinal injury caused by Eimeria spp. impairs the phosphotransfer network and gain weight in experimentally infected chicken chicks.

Parasitic infections caused by protozoan belonging to genus Eimeria are considered important for the poultry industry, due to their severe intestinal lesions and high mortality rates, causing significant economic losses. Although several mechanisms of coccidiosis pathogenesis are known, the effects of this infection on intestinal enzymes linked to adenosine triphosphate (ATP) metabolism, as creatine kinase (CK), adenylate kinase (AK), and pyruvate kinase (PK), remain unknown. Thus, the aim of this study was to evaluate whether coccidiosis impairs enzymes linked ATP metabolism in the intestine of chicken chicks. For this, 42 animals that were 2 days old were divided into two groups: uninfected (the negative control group) and experimentally infected on second day of life (the positive control group). On days 5, 10, and 15 post-infection (PI), fecal samples were collected for oocyst counts; intestinal tissue was collected in order to evaluate CK, AK, and PK activities, as well as parameters of the oxidative stress and histopathology. On days 10 and 15 PI, infected animals showed high counts of oocysts in fecal samples and intestinal lesions compared to the control group. Cytosolic CK activity was higher in infected animals on days 10 and 15 PI compared to the control group, while mitochondrial CK activity was lower on days 5, 10, and 15 PI. Also, AK activity was lower in infected animals on days 10 and 15 PI compared to control group, while no differences were observed between groups regarding PK activity. In relation to parameters of oxidative stress, intestinal lipid peroxidation and reactive oxygen species levels were higher in infected animals on days 10 and 15 PI compared to the control group, while non-protein thiol levels were lower on day 10 PI. On the 15th day, infected animals had lower body weight (P < 0.05). Based on this evidence, inhibition of mitochondrial CK activity causes an impairment of intestinal energetic homeostasis possibly through depletion on ATP levels, although the cytosolic CK activity acted as an attempt to restore the mitochondrial ATP levels through a feedback mechanism. Moreover, the impairment on energy metabolism appears to be mediated by excessive production of intestinal ROS, as well as oxidation of lipids and thiol groups.

Oxidative stress linked to changes of cholinesterase and adenosine deaminase activities in experimentally infected chicken chicks with Eimeria spp.

Both oxidative stress and alterations in adenosinergic and cholinergic systems participate in initiation and progression of parasitic infectious diseases. Nevertheless, the involvement of these pathways during eimeriosis remains poorly understood. Therefore, the aim of this study was to evaluate the involvement of adenosinergic and cholinergic systems in regulation of inflammatory response and oxidative stress in chicken chicks experimentally infected with Eimeria spp. Two groups were formed for comparison at 3 time points (days 5, 10 and 15) of infection (PI): uninfected (control) and infected. Erythrocyte counts, hematocrit and hemoglobin levels were lower in infected chicks on day 15 post-infection (PI). Total leukocytes, heterophil and lymphocyte counts were higher in infected chicks on days 5 and 10 PI, while eosinophil counts were higher only on day 10 PI. Serum levels of total protein and globulins were higher in infected chicks on days 10 and 15 PI, while triglycerides and cholesterol levels were lower on day 15 PI. Acetylcholinesterase activity in total blood and butyrylcholinesterase activity in serum were higher in infected chicks on day 15 PI, while adenosine deaminase activity was higher on day 10 PI and lower on day 15 PI compared with the respective control. Finally, serum levels of reactive oxygen species and catalase activity in total blood were higher in infected chicks on day 15 PI, while superoxide dismutase activity in total blood was lower at the same time of infection. These data suggest that cholinergic and adenosinergic systems display a pro-inflammatory profile that contributes to impairment of immune and inflammatory responses in a mixed Eimeria infection. Furthermore, oxidative stress may contribute to clinical signs of disease as well as to pathogenesis. In summary, the impairment of immune response and alterations in blood antioxidant/oxidant status contributes to disease pathophysiology.

Disturbance of energetic homeostasis and oxidative damage provoked by trichlorfon as relevant toxicological mechanisms using silver catfish as experimental model.

Recent evidences have suggested the involvement of phosphoryl transfer, catalyzed by creatine kinase (CK), adenylate kinase (AK) and pyruvate kinase (PK), to metabolic alterations and impairment of bioenergetics homeostasis linked to adenosine triphosphate (ATP) production, and utilization during exposure to pesticides. It is recognized that sublethal concentrations of trichlorfon alter hepatic and branchial metabolism, but the pathways involved in this process remains unknown. Thus, the aim of this study was to evaluate whether phosphoryl transfer network can be a pathway involved in the hepatic and branchial metabolic alterations during exposure to sublethal concentrations of trichlorfon using silver catfish Rhamdia quelen as experimental model. Hepatic and branchial CK (cytosolic and mitochondrial isoforms) and PK activities were inhibited after 48 h of exposure to 11 and 22 mg/L trichlorfon compared to control group, while AK activity did not differ between groups. In addition, sodium-potassium pump (Na+, K+-ATPase) activity was lower after 48 h of exposure to 22 mg/L trichlorfon compared to control group. Thiobarbituric acid reactive substances (TBARS) were higher in liver samples after 24 h of exposure to 22 mg/L trichlorfon compared to control group, as well as after 48 h of exposure to 11 and 22 mg/L trichlorfon in liver and gills. Finally, hepatic and branchial non-protein thiol (NPSH) levels were lower after 48 h of exposure to 11 and 22 mg/L trichlorfon. All evaluated parameters did not recover after 48 h in clean water. Based on these evidence, the impairment of phosphoryl transfer network can be considered a pathway involved in the hepatic and branchial metabolic alterations during exposure to sublethal concentrations of trichlorfon. Moreover, alterations on CK and PK activities provoke an impairment on Na+, K+-ATPase activity, which can be mediated by lipid oxidative damage and reduction of NPSH content.