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The aim was to determine whether probiotics-feeding can affect the expression and localization of avian beta defensins (AvBDs) and proinflammatory cytokines in response to Salmonella minnesota lipopolysaccharide (LPS) in the gastrointestinal tract. One-day-old male Chunky broiler chicks were fed with or without 0.4% probiotics for 7 days (P-group and non-P-group, respectively). Then, they were orally challenged with no LPS (0-LPS), 1 µg LPS (1-LPS), or 100 µg LPS (100-LPS) (n = 5, each), in experiment 1, and with no LPS and 1 µg LPS (n = 6, each) in experiment 2. Five hours after LPS challenge, the proventriculi and ceca were collected. A total of seven and eight AvBDs were identified in proventriculus and cecum, respectively. The density of ir-AvBD12 in the surface epithelium of proventriculus increased in the P-group in response to 1-LPS and 100-LPS stimulation. In experiment 1, the expression of two AvBDs in the proventriculus and six AvBDs in the cecum of 1-LPS chicks was higher in P-group than in the non-P-group. Results of experiment 2 showed similar tendency to experiment 1. These results suggest that probiotics-feeding may enhance the immunodefense system mediated by AvBDs but not by cytokine, against infection by Gram-negative bacteria., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.)

Extended-spectrum cephalosporin (ESC)-resistant Salmonella have been described at a low level in the EU, nevertheless the increasing importation of poultry meat could be an important source of epidemic strains carrying ESC resistance genes. This study evaluated ESC resistance and its genetic platform among Salmonella isolates from poultry meat products imported into Portugal as well as clonal relatedness of the isolates. All Salmonella isolates recovered from samples of fresh meat destined for import into the EU in the scope of Portuguese official border control (2014-2015) were studied. Antibiotic susceptibility and β-lactamase production was determined by disk diffusion/microdilution. Molecular studies included detection of genes encoding acquired AmpC and extended-spectrum β-lactamases, plasmid-mediated quinolone resistance and other antibiotic resistance genes by PCR/sequencing, and clonality by MLST and XbaI-PFGE. Plasmid characterisation was assessed by conjugation assays, replicon typing (PCR-PBRT/pMLST) and hybridisation experiments (I-CeuI/S1-PFGE nuclease). Isolates belonged to Salmonella Heidelberg (n = 6; ST15/eBG26) and Salmonella Minnesota (n = 1; ST548/eBG77) and presented multidrug-resistant profiles, including to ESCs and/or fluoroquinolones. All but one carried bla CMY-2 , located on two epidemic plasmids, IncA/C (ST2, n = 5) or transferable IncI1 (ST12, n = 1). Salmonella Heidelberg was associated with five PFGE types, including one similar to an American epidemic clone. This study reveals imported poultry products as a source of uncommon and/or invasive ESC-resistant Salmonella strains in the EU. The increase of clinically relevant poultry-related serotypes in Europe must be taken into account in the current monitoring of antibiotic resistance trends and in re-evaluation of food regulations., (Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.)

In this study, we aimed to evaluate the antioxidant and anti-inflammatory properties of Opuntia ficus-indica cactus cladode extracts in microglia BV-2 cells. Inflammation associated with microglia activation in neuronal injury can be achieved by LPS exposure. Using four different structurally and biologically well-characterized LPS serotypes, we revealed a structure-related differential effect of LPS on fatty acid β-oxidation and antioxidant enzymes in peroxisomes: Escherichia coli -LPS decreased ACOX1 activity while Salmonella minnesota -LPS reduced only catalase activity. Different cactus cladode extracts showed an antioxidant effect through microglial catalase activity activation and an anti-inflammatory effect by reducing nitric oxide (NO) LPS-dependent production. These results suggest that cactus extracts may possess a neuroprotective activity through the induction of peroxisomal antioxidant activity and the inhibition of NO production by activated microglial cells.