ABSTRACT
Salmonella is the main human pathogen present in the poultry chain. Salmonella Heidelberg is one of the most important serovars for public health since it has been frequently isolated in broiler chickens from different countries and may present multidrug resistance (MDR). This study was carried out with 130 S. Heidelberg isolates collected from pre-slaughter broiler farms in 2019 and 2020 in 18 cities from three Brazilian states to study relevant aspects regarding their genotypic and phenotypic resistance. The isolates were tested and identified using somatic and flagellar antiserum (0:4, H:2, and H:r), and an antimicrobial susceptibility test (AST) was performed against 11 antibiotics for veterinary use. The strains were typed by Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR, and representatives of the main clusters of the identified profiles were sequenced by Whole Genome Sequencing (WGS). AST results showed that all isolates were resistant to sulfonamide, 54 % (70/130) were resistant to amoxicillin, and only one was sensitive to tetracycline. Twelve isolates (15.4 %) were MDR. The dendrogram obtained from the ERIC-PCR showed that the strains were grouped into 27 clusters with similarity above 90 %, with some isolates showing 100 % similarity but with different phenotypic profiles of antimicrobial resistance. Identical strains collected on the same farm on other dates were identified, indicating that they were residents. WGS identified 66 antibiotic-resistance genes. The sul2 (present in all sequenced samples) and tet(A) genes were highlighted and validated in the experimental analysis. The fosA7 gene was also identified in all sequenced samples, but resistance was not observed in the phenotypic test, possibly due to the heteroresistance of the S. Heidelberg strains evaluated. Considering that chicken meat is one of the most consumed meats in the world, the data obtained in the present study can corroborate the mapping of the origin and trends of antimicrobial resistance.
Subject(s)
Chickens , Drug Resistance, Multiple, Bacterial , Animals , Humans , Brazil , Drug Resistance, Multiple, Bacterial/genetics , Chickens/microbiology , Microbial Sensitivity Tests , Salmonella , Anti-Bacterial Agents/pharmacologyABSTRACT
Microbiota alterations are observed in pathological conditions, and their regulation is a subject of great interest. Gut microbes are affected by diet, and plant polyphenols may have positive effect on gut microbiota; however, plant-derived extracts may have toxic effects. Guarana (Paullinia cupana Mart.) is a nontraditional medicinal plant applied worldwide. Guarana yields an alkaloid and polyphenol-rich seed with antimicrobial, antioxidant, and anti-inflammatory properties, where caffeine is the major compound. We evaluated the effects of guarana seed powder (GSP) and purified caffeine on gut microbial composition and redox and inflammatory parameters in Wistar rats after 21 days of treatment. Fecal microbiota was analyzed utilizing 16S rDNA sequencing. Antioxidant enzymes activities from liver, kidney, and colon, as well as oxidative damage markers, were evaluated. Total nonenzymatic antioxidant potential was also evaluated. Microbiota was altered by both treatments, GSP and caffeine, without loss of diversity. In the liver, the kidney, and the colon, we observed a decrease in the antioxidant enzymes activities in the GSP group with no increase in the expression of oxidative damage markers, although some enzymes were also regulated by caffeine. Taken together, these results suggested that GSP ameliorates redox parameters but negatively affected gut microbiota, partially via caffeine.
Subject(s)
Caffeine/pharmacology , Gastrointestinal Microbiome/drug effects , Oxidative Stress/drug effects , Theobromine/pharmacology , Theophylline/pharmacology , Animals , Antioxidants/pharmacology , Caffeine/chemistry , Dysbiosis/chemically induced , Dysbiosis/microbiology , Dysbiosis/pathology , Male , Oxidation-Reduction/drug effects , Paullinia/chemistry , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Rats , Rats, Wistar , Seeds , Theobromine/chemistry , Theophylline/chemistryABSTRACT
The development of a simulator for a packing and weighing system (PWS) of granulated powder is described. It employed system identification to obtain the deterministic part of the model and stochastic processes to reproduce disturbances. It reproduces the fluctuations in carton weight observed in real packing systems. Its final use is to evaluate proposed improvements in the PWS, aiming at reducing overweight and underweight. Its performance is satisfactory, as the oscillations observed in the carton weights, due to powder density variability, are close to reality as well as the monetary losses due to overweight and underweight and the power spectral density graphs of the real and simulated weights.
