|Iwen, Peter -|
Submitted to: International Association for Food Protection
Publication Type: Abstract Only
Publication Acceptance Date: March 2, 2011
Publication Date: July 31, 2011
Citation: Bosilevac, J.M., Iwen, P.C. 2011. Sensitivity of Mycobacterium bovis to common beef processing interventions [abstract]. International Association for Food Protection, Milwaukee, WI. July 31 - August 3, 2011. Poster Abstract P2-42, p. 65. Technical Abstract: Introduction. Cattle infected with Mycobacterium bovis, the causative agent of bovine tuberculosis and a relevant zoonosis to humans, may be sent to slaughter before diagnosis of infection because of slow multiplication of the pathogen. Purpose. This study evaluates multiple processing interventions to determine a best practice as a means to control the spread of M. bovis in the beef processing environment. Methods. Four strains of M. bovis isolated from cattle were evaluated in vitro for their ability to survive when exposed to seven commonly used interventions for 30 s in suspension. Treatments consisted of hot water (HW) at 65 deg, 70 deg, 75 deg, 80 deg, and 85 deg C; lactic acid (LA) at 2 and 5% used at 25 deg and 50 deg C; acidified sodium chlorite (ASC) at 500 and 1,200 ppm; Inspexx200™ (prepared at 220 ppm peroxyacetic acid, POAA); FreshFx™ (FF) at 2%; chlorine (Cl) at 50 ppm and bromine (Br) at 300 ppm, prepared from Bovibrom™ and from hypobromous acid. All effects were measured by most probable number (MPN) determinations and colony forming unit (CFU) counts then compared to the level of M. bovis remaining after control (25 deg C) treatments in saline. Results. Treatments with Cl, FF and either concentration of LA at ambient temperatures did not reduce the number of M. bovis. However, treatment with either concentration of LA at 50 deg C, POAA, or Br reduced M. bovis by 1.5 to 2 log CFU when compared to the control (P < 0.05). Additionally, both concentrations of ASC and hot-water at greater than or equal to 75 deg C reduced M. bovis by at least 3 log CFU (P < 0.05) when compared to controls. In a timed exposure to 75 deg C HW the reduction was observed at 5 sec. Significance. The most effective methods to reduce M. bovis viability were treatment with HW at or above 75 deg C and 500 or more ppm of ASC. Additional studies are recommended to evaluate efficacy of these treatments on carcass surfaces.