Occurrence of Salmonella spp. in the broiler production chain

ABSTRACT Brazilian chicken meat is exported to more than 150 countries and consumed by consumer markets that demand high quality and food safety, thus, requiring very strict control of pathogens present in food to guarantee these rigorous safety standards. This study evaluates the reports from the Salmonella spp. Control and Monitoring Program of the Brazilian Ministry of Agriculture, Livestock and Food Supply of seven slaughterhouses inspected by the Federal Inspection Service from the western region of Paraná state, Brazil, from March 2017 to February 2019. The broiler litter swab and carcass analyses revealed a Salmonella spp. positivity ratio of 5.9% (19/319) and 23.5% (75/319), respectively. The concomitant presence of Salmonella spp. in the broiler litter swab and chicken carcasses occurred in 58% of the positive samples. The most frequently isolated serovar in the carcasses was Salmonella Heidelberg (85.3%) followed by Salmonella spp. (10.6%). During slaughter, carcass positivity to Salmonella spp. was significantly different (p=0.047) between the first (19.6%) and the second (29.4%) shifts. The results alert for the possibility of carcass contamination during slaughtering and, therefore, more stringent hygiene measures between shifts must be implemented to mitigate carcass contamination

Evidence for eosinophil recruitment, leukotriene B4 production and mast cell hyperplasia following Toxocara canis infection in rats

It is well known that eosinophilia is a key pathogenetic component of toxocariasis. The objective of the present study was to determine if there is an association between peritoneal and blood eosinophil influx, mast cell hyperplasia and leukotriene B4 (LTB4) production after Toxocara canis infection. Oral inoculation of 56-day-old Wistar rats (N = 5-7 per group) with 1000 embryonated eggs containing third-stage (L3) T. canis larvae led to a robust accumulation of total leukocytes in blood beginning on day 3 and peaking on day 18, mainly characterized by eosinophils and accompanied by higher serum LTB4 levels. At that time, we also noted increased eosinophil numbers in the peritoneal cavity. In addition, we observed increased peritoneal mast cell number in the peritoneal cavity, which correlated with the time course of eosinophilia during toxocariasis. We also demonstrated that mast cell hyperplasia in the intestines and lungs began soon after the T. canis larvae migrated to these compartments, reaching maximal levels on day 24, which correlated with the complete elimination of the parasite. Therefore, mast cells appear to be involved in peritoneal and blood eosinophil infiltration through an LTB4-dependent mechanism following T. canis infection in rats. Our data also demonstrate a tight association between larval migratory stages and intestinal and pulmonary mast cell hyperplasia in the toxocariasis model

Discovery and Kinetic Profiling of 7-Aryl-1,2,4-triazolo[4,3-a]pyridines: Positive Allosteric Modulators of the Metabotropic Glutamate Receptor 2

We report the synthesis and biological evaluation of a series of 7-aryl-1,2,4-triazolo[4,3-c]pyridines with mGlu(2) positive allosteric modulator (PAM) activity and affinity. Besides traditional in vitro parameters of potency and affinity, kinetic parameters k(on), k(off) and residence time (RT) were determined. The PAMs showed various kinetic profiles; k(on) values ranged over 2 orders of magnitude, whereas RT values were within a 10-fold range. Association rate constant k(on) was linearly correlated to affinity. Evaluation of a short, medium, and long RT compound in a label-free assay indicated a correlation between RT and functional effect. The effects of long RT compound 9 on sleep-wake states indicated long RT was translated into sustained inhibition of rapid eye movement (REM) in vivo. These results show that affinity-only driven selection would have resulted in mGlu(2) PAMs with high values for k(on) but not necessarily optimized RT, which is key to predicting optimal efficacy in vivo

Applications of scalar attractor solutions to Cosmology

We develop a framework to study the phase space of a system consisting of a scalar field rolling down an arbitrary potential with varying slope and a background fluid, in a cosmological setting. We give analytical approximate solutions of the field evolution and discuss applications of its features to the issues of quintessence, moduli stabilisation and quintessential inflation.Comment: 9 pages, 7 figures. Accepted for publication in PR