Anin-vitroinvestigation into the efficacy of disinfectants used in the duck industry againstSalmonella

Abstract

In 2010, 81 confirmed cases of Salmonella Typhimurium DT8 were reported across England and Northern Ireland - an increase of 26% from 2009 and 41% since 2008. Five cases were hospitalized and one death reported, with a strong association found between cases and the consumption of duck eggs. Once present on farms, Salmonella may become persistent and can survive for long periods of time in residual organic matter, increasing risk of infection for follow-on flocks if cleaning and disinfection is not carried out effectively. The aim of this study was to investigate the efficacy of a range of disinfectants used by the duck industry against Salmonella using laboratory models. Sixteen products were selected from seven chemical groups and the Minimum Inhibitory Concentration and Minimum Bactericidal Concentrations determined. Each product was also tested at the recommended general orders (GO) concentration using a faecal suspension model to mimic boot dips and a surface contamination model to simulate contaminated building fabric and equipment. In the faecal suspension model, all products were effective at 2 × GO concentration, and activity was more inconsistent at GO concentration. At 0.5 × GO concentration, iodine-based and quaternary-ammonium-compound-based products were significantly less effective than products within other chemical groups (P < 0.001). Glutaraldehyde-based products were significantly more effective than the other products in the surface contamination tests (P < 0.001). Chlorocresol-based products were found to be most effective for use in boot dips and aldehyde-based products for surface disinfection, although there was variability between products within a chemical group.

Evaluation of an enhanced cleaning and disinfection protocol in Salmonella contaminated pig holdings in the United Kingdom

“…Formaldehyde, particularly if applied by spraying, has demonstrated the highest efficacy in in vitro and on farm studies, however, due to its potentially hazardous properties, it is recommended that it is applied by specialist contractors [ 20 , 23 ] and is difficult to apply safely on pig farms unless there is a long empty period. Glutaraldehyde and QAC combinations have been shown to have good effectiveness, even in the presence of some residual organic matter [ 16 , 18 , 22 ]. The intervention buildings in the study described here were significantly less likely to be positive for Salmonella than the control buildings after C&D. Only one intervention building (farm 228C) had detectable residual Salmonella contamination after C&D. The reason for this apparent failure is uncertain, but monophasic S .…”

“…The effective removal of organic matter is crucial to eliminate Salmonella from farm buildings, but this can be hindered by the presence of cracks and crevices in floors, walls and ceilings and the formation of biofilms [ 16 , 17 ]. The ability of disinfectants to eliminate Salmonella is influenced by the type of disinfectant chosen and its concentration, and may be severely compromised by the presence of organic matter [ 16 , 18 , 19 ]. Different types of disinfectant are commercially available, such as quaternary ammonium compounds (QAC) products containing glutaraldehyde or formaldehyde, peroxygen or peracetic acid based compounds, iodine based compounds or chlorocresols.…”

“…Different types of disinfectant are commercially available, such as quaternary ammonium compounds (QAC) products containing glutaraldehyde or formaldehyde, peroxygen or peracetic acid based compounds, iodine based compounds or chlorocresols. Their effectiveness against Salmonella varies greatly, as demonstrated in several in vitro and on farm studies [ 16 , 18 , 20 – 23 ]. Currently, disinfectants intended for veterinary use may be assessed for efficacy using standardised methods of either suspension or surface types, which do not use the matrices commonly found on farms, and therefore the efficacy of a disinfectant in field conditions can be overestimated [ 22 ].…”

Results from a study of the effect of enhanced cleaning and disinfection on Salmonella prevalence in finisher pig building

“…Environmental Salmonella contamination increases the risk of Salmonella shedding in newly introduced batches of pigs [4]. The ability of disinfectants to eliminate Salmonella is influenced by the type of disinfectant chosen and its concentration, and may be severely compromised by the presence of organic matter [5,6]. Different types of disinfectant are commercially available, such as quaternary ammonium compounds (QAC) products containing glutaraldehyde or formaldehyde, peroxygen or peracetic acid based compounds, iodine based compounds or chlorocresols.…”

“…Different types of disinfectant are commercially available, such as quaternary ammonium compounds (QAC) products containing glutaraldehyde or formaldehyde, peroxygen or peracetic acid based compounds, iodine based compounds or chlorocresols. Their effectiveness against Salmonella varies greatly, as demonstrated in several in vitro and on farm studies [5,6,7]. Currently, disinfectants intended for veterinary use may be assessed for efficacy using methods which do not use the matrices commonly found on farms, and therefore the efficacy of a disinfectant in field conditions can be overestimated.…”