Effect of selected feed additives to improve growth and health of dairy calves.

The aim was to evaluate the effect of different feed additives on intake, performance, and fecal consistency index (FCI) of dairy calves from 6-60 d of age and its residual effect 15 d after weaning. Fifty Holstein calves (38 ± 1.0 kg BW) were fed 5 L/d of milk plus starter feed until weaning, and corn silage and concentrate after weaning.

Yersinia enterocolitica in a Brazilian pork production chain: Tracking of contamination routes, virulence and antimicrobial resistance.

This study aimed to track Yersinia enterocolitica contamination in a pork production chain in Minas Gerais, Brazil, and to characterize the virulence and antibiotic resistance of isolates. Samples were collected from four different steps of the pork production chain (pig farm, carcass, processing environment and end product; n = 870), and tested for the presence of Y. enterocolitica.

Expression of genes associated with stress conditions by Listeria monocytogenes in interaction with nisin producer Lactococcus lactis.

The use of nisin producers in foods is considered a mitigation strategy to control foodborne pathogens growth, such as Listeria monocytogenes, due to the production of this bacteriocin in situ. However, when the bacteriocin does not reach an adequate concentration, the target bacteria can develop a cross-response to different stress conditions in food, such as acid, thermal and osmotic. This study aimed to evaluate the interaction of a nisin-producing strain of Lactococcus lactis DY-13 and L.

Changes in the Salmonella enterica Enteritidis phenotypes in presence of acyl homoserine lactone quorum sensing signals.

Quorum sensing is used by bacteria to coordinate gene expression in response to population density and involves the production, detection and response to extracellular signaling molecules known as autoinducers (AIs). Salmonella does not synthesize the AI-1, acyl homoserine lactone (AHL) common to gram-negative bacteria; however, it has a receptor for AI-1, the SdiA protein. The effect of SdiA in modulating phenotypes of Salmonella has not been elucidated.