Completed Research

The research determined if strains of Lm develop filaments under stress conditions. These filaments may contribute to pathogen survival and subsequently multiply in contaminated product or human hosts.

The study characterized the genetic basis for the apparent differences in prevalence of different serotypes and strain types of L. monocytogenes in the processing plant environment and in foods, specifically if genes mediating adaptations are highly relevant to the ability of the pathogen to colonize the processing plant and contaminate RTE meats.  

The overall objective is to validate effectiveness of antimicrobial compound treatments on inactivation of STEC and Salmonella (MDR versus non-MDR strains) inoculated fresh beef. AMIF recently funded ARS to conduct a similar study on the following non-O157 STEC: O26, O103, O111, and O145. This study completed the work by adding the other two non-O157 STEC from the CDC’s top six and include MDR and non-MDR Salmonella Typhimurium and Newport.

This research evaluated peroxyacetic acid, novel organic acids alone or in combination with a non-ionic surfactant on beef trimmings against E. coli O157:H7, O26, O103, O111, O121, O45, and O145 and Salmonella Typhimurium DT 104, Newport MDR-AmpC to achieve maximum ground beef product safety without altering product quality.

The goals of this project were to develop and implement new control strategies for L. monocytogenes in commercial retail delis and to test the ability of these strategies to reduce and control L. monocytogenes contamination.
Project co-sponsored by the Food Marketing Institute Foundation.

Research demonstrated that STEC O26, O45, O103, O111, O121, and O145 strains expressing different flagellar types and variants of intimin adhered to bovine colonic epithelium and induced the formation of attaching-effacing lesions. Interventions that block the effects of flagella, intimin, and other adherence mechanisms in non-O157 STEC may be effective for pre-harvest control of non-O157 STEC in cattle.

The white paper summarizes all historical data on C. difficile infections in humans; evaluates epidemiological data on animals, non-animal sources, and foods that have the potential to cause human infections and factors that affect transmission of C. difficile; evaluates hospital acquired C. difficile infections; evaluates worldwide understanding of C. difficile infections and their sources; and identifies the data gaps and discusses how these gaps influence the understanding of C. difficile and proposes tasks needed to close the gaps.

The project evaluated supplementation of cattle diets with Lactobacillus acidophilus NP51 to reduce Salmonella in lymph nodes at slaughter and concluded high doses of NP51 could be a viable intervention.

This white paper summarizes all epidemiological data on the relationships between food and non-food vehicles and vectors, and human illnesses caused by Salmonella published in the past 5 years; compares data published since 2008 with that presented in the 2009 white paper for AMIF on vehicles associated with human illness caused by Salmonella; describes surveillance strategies, regulations, and industry initiatives to control this pathogen; and identifies gaps in understanding of food attribution data and surveillance strategies for illness caused by Salmonella.

This project determined the prevalence, level, and types of O157 and non-O157 Shiga toxin-producing E. coli (STEC) in cattle from different production systems.