Feedmill IPM

Project Title: Bacteria associated with stored-product insects in feed mills and their susceptibility to antibiotics

Investigators: (past) Zeb Larson, Bh. Subramanyam, Ludek Zurek, Kantha and Tim Herrman

Objectives: To determine types and numbers of stored-product insects found in eight feed mills in the Midwestern US, isolate gut bacteria from live adults collected from products, culture gut enterococci and evaluate their susceptibility to antibiotics used for treating human bacterial infections.

Methods: Commercial food-baited pit fall traps and pheromone-baited sticky traps were used (50-100/facility) to capture stored-product insect adults in the eight mills. Mills were sampled 2 to 4 times during 2002-2003.  In addition, product samples were collected from each mill to extract live adults. Individual insects will be homogenized and plated on specific media to isolate enterococci. Diffusion disk assay will be used to determine susceptibility to nine antibiotics.

Impacts: We understand very little about the types and numbers of insects found in feed mills, and their importance as vectors of antibiotic resistance genes or as reservoirs of bacteria that could contaminate feed products.  Our research sheds new light on these aspects.