Beta-lactam antibiotics prevent Salmonella-mediated bovine encephalopathy regardless of the β-lactam resistance status of the bacteria

This study assessed the capacity of beta-lactam antibiotics to prevent salmonella-mediated encephalopathy in calves given the putative neuroprotective effects of these drugs of increasing glutamate export from the brain. Both ampicillin and ceftiofur prevented the development of encephalopathy despite resistance of the inoculated Salmonella enterica serovar Saint-Paul isolate to both drugs. A glutamate receptor antagonist also prevented this salmonella-mediated encephalopathy. Glutamate exporters were hyper-expressed in the presence of beta-lactam antibiotics while a glutamate export inhibitor obviated the effects of these antibiotics, demonstrating a neuroprotective effect through glutamate export from the brain. The findings indicate that beta-lactam antibiotics remain an important treatment option for this atypical form of bovine salmonellosis. (C) 2011 Elsevier Ltd. All rights reserved.