Association between Salmonella sp. and Yersinia enterocolitica infection in swine

By: Erin Shaw

Michigan State University, Class of 2013

Shaw, Erin; Funk, Julie; Plovanich-Jones, Anne E.; College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824

Swine are known reservoirs for both Salmonella and Yersinia enterocolitica. Both are foodborne pathogens and can result in zoonotic disease if contamination of pork products occurs during harvest.  The epidemiology of Y. enterocolitica and Salmonella in swine is not well understood, and cost-effective preharvest control measures have not been identified. Previous reports from experimental studies in mice suggest that, via quorum-sensing, Salmonella detects Y. enterocolitica signals, increasing Salmonella colonization (Dyszel et al, 2009). This may present an opportunity for preharvest control via targeting Y. enterocolitica infection or disruption of quorum sensing. Demonstration of this association in naturally infected swine has not been demonstrated.

Click to read more ...

A New Look at Vaccines

By: Laura Stoeker

North Carolina State University

Our companion animals are routinely vaccinated against infectious diseases that target the respiratory, intestinal, and reproductive tracts, collectively known as mucosal tissue. Veterinarians typically inject vaccines into the muscle, leading to a system-wide immune response. However, recent research suggests that vaccine effectiveness may be improved by administering a vaccine at the pathogen’s point of entry, leading to a stronger local immune response that may prevent initial entry of the pathogen into the host.

Click to read more ...

An Investigation of the Synergistic Effects of Procaine G Penicillin and Oxytetracycline on the bacillum Listeria monocytogenes

By: Alicia Agnew

Virginia-Maryland Regional College of Veterinary Medicine, Class of 2013

Listeria monocytogenes is a food-borne pathogen that causes disease in twenty-eight mammalian species including humans.  The bacterium is opportunistic, and for this reason, outbreaks tend to be sporadic in nature.  Listeria monocytogenes is ubiquitous in nature, so forty environmental samples were collected from a goat farm in Maryland.  Twenty samples were then isolated to purity using Oxford Enrichment media.  These samples were then tested for sensitivity to the antibiotics Penicillin Procaine G and Oxtetracycline.  I hypothesized that the combination of these two drugs would have a synergistic effect in inhibition of bacterial growth.  Microtitrator tests were carried out for each environmental sample as well as a sample obtained from a commercial lab.  The minimum inhibitory concentrations of Procaine G and Oxytetracycline were determined individually for each sample and then in combination for each sample to test for synergism.  The results of the study were inconclusive, showing neither an antagonistic nor a synergistic effect when the two drugs were used in combination.