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Chapter 4
outflow of excess disinfectant diluted water may create a reservoir of
antimicrobial resistant bacteria circulating in the environment of a food
plant. Antimicrobial compounds associated with meat processing and
washing include hydrogen peroxide, ozone, chlorine, sodium chlorite,
peroxyacetic acid or trisodium phosphate [200].
Post slaughter washing may produce a build-up of antimicrobial
compounds meat products or create a reservoir of excess antimicrobial
resistant bacteria in the environment of a food processing area. During the
surveillance of four slaughter houses, Arguello et al. detected Salmonella in
the majority of areas in all four slaughter houses tested. In 3 of the 4
slaughter houses, the bung droppers (used for cutting the carcasses) were
still contaminated with Salmonella after application of the processes
intended to achieve sterilization [201]. Arguello et al. also isolated
Salmonella from contaminated scalding tanks used to wash the carcasses
[201]. The results from the surveillance indicated that sterilization and
disinfection procedures in use at the time of testing were not effective
[201].
The presence of Salmonella after the cleaning and decontamination
processes may also indicate a build up of disinfectant resistant bacteria or
biofilm formation. Anderson et al. investigated the formation of a multi
Pseudomonas species biofilm inside a polyvinyl chloride pipe (PVC pipe)
over the course of eight weeks[202]. The PVC pipe was then treated with
disinfectant agents for 7 days at the recommended working concentrations.
Sterile water was then used to examine if remaining cells could
contaminate the flow-through effluent. As a result of the biofilm formation,
the pathogen was found to contaminate the disinfectant agents recovered
from the surface and the water used as wash-out effluent for up to 7 days
post treatment [202]. The disinfectants used included chlorine, phenolic
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