Abstract
The handling and packing of eggs in commercial production creates opportunities for the spread of those pathogenic microorganisms that can survive on the surfaces of eggs and equipment, and in organic soiling such as egg contents and faeces. Salmonella Enteritidis is a key zoonotic pathogen, and its spread between egg production premises in recent years has implicated cross-contamination via egg handling and packing equipment. Cleaning and disinfection to prevent such spread have to be performed using food-grade agents, which limits the options available to manufacturers of disinfectants and sanitisers. The present review examines the active components of such products, based upon the most frequently used disinfectants and sanitisers in this part of the egg industry in the United Kingdom. Peer-reviewed data are summarised for the main bactericidal elements, comprising sodium hypochlorite and surfactants including quaternary ammonium compounds. In addition, there is brief consideration of ancillary agents with cleaning, pH-modulating, water-softening and additional bacter-icidal effects. The amount of published surveillance and experimental data for the effect of these agents on Salmonellaspp. and related organisms is very variable, and in addition findings illustrate substantial differences in biocidal effect between and within studies. Some of these relate to test variables such as surface material, concentration, exposure time, and the presence of organic soil or biofilm. Other differences reflect inherent variability in disinfectant testing. It is suggested that inadequate disinfection may occur under some foreseeable conditions of application, even if concentration and exposure time recommendations are followed. Further testing may be useful if it more closely replicates the products and conditions of use.