title: The efficacy of different cleaning and disinfection procedures to reduce Salmonella and Enterobacteriaceae in the lairage environment of a pig abattoir.
abstract: This study investigated several cleaning and disinfection protocols for their ability to eliminate Salmonella and to reduce levels of Enterobacteriaceae, within the lairage pens of a commercial pig abattoir. Eight protocols were evaluated in each of 12 lairage pens at the end of the slaughtering day on 3 occasions (36 pens/protocol): (P1) high-pressure cold water wash (herein referred to as high-pressure wash); (P2) high-pressure wash followed by a quaternary ammonium compound (QAC)-based disinfectant without rinsing; (P3) high-pressure wash followed by a chlorocresol-based disinfectant without rinsing; (P4) high-pressure wash followed by a sodium hydroxide/sodium hypochlorite detergent with rinsing; (P5) P4 followed by P2; (P6) P4 followed by P3; (P7) P5 with drying for 24-48h; and (P8) P6 with drying for 24-48h. Two floor swabs and one wall swab were taken from each lairage pen before and after each protocol was applied, and examined for the presence of Salmonella and enumeration of Enterobacteriaceae. High-pressure washing alone (P1) did not reduce the prevalence of Salmonella in the lairage pens. When high-pressure washing, the probability of detecting Salmonella following application of the chlorocresol-based disinfectant (P3) was lower than with the QAC-based disinfectant, P2 (14.2% versus 34.0%, respectively; p<0.05). The probability of detecting Salmonella after the combined use of detergent and the chlorocresol-based disinfectant (P6) was also lower than application of detergent followed by the QAC-based disinfectant, P5 (2.2% versus 17.1%, respectively; p<0.05). Drying of pens (P7 and P8) greatly reduced the probability of detecting Salmonella. Only 3.8% of swabs were Salmonella-positive 48h after cleaning with detergent and the QAC-based disinfectant (P7); while an eradication of Salmonella was achieved 24h after cleaning with detergent and the chlorocresol-based disinfectant, P8. A reduction in Enterobacteriaceae counts to below the limit of detection (LOD; 10CFU/cm2) was achieved following cleaning with detergent and disinfection with the chlorocresol-based disinfectant, regardless of drying (p<0.05), whereas, applying detergent and the QAC-based disinfectant (P7) did not reduce Enterobacteriaceae counts to below the LOD. Therefore ensuring that lairage pens are allowed to dry after intensive cleaning with detergent and a chlorocresol-based disinfectant is recommended as the most effective hygiene routine to eliminate Salmonella and reduce Enterobacteriaceae counts.
authors.affiliation: Teagasc, Food Research Centre, Ashtown, Dublin 15, Ireland; Department of Science, Waterford Institute of Technology, Waterford, Ireland; Teagasc, Pig Development Department, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland.
authors.forename: Kavita
authors.initials: K
authors.lastname: Walia
authors.affiliation: Teagasc, Food Research Centre, Ashtown, Dublin 15, Ireland.
authors.forename: Hector
authors.initials: H
authors.lastname: Argüello
authors.affiliation: Teagasc, Food Research Centre, Ashtown, Dublin 15, Ireland; School of Veterinary Medicine, University College Dublin, Dublin, Ireland; Teagasc, Pig Development Department, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland.
authors.forename: Helen
authors.initials: H
authors.lastname: Lynch
authors.affiliation: Teagasc, Food Research Centre, Ashtown, Dublin 15, Ireland.
authors.forename: Jim
authors.initials: J
authors.lastname: Grant
authors.affiliation: School of Veterinary Medicine, University College Dublin, Dublin, Ireland.
authors.forename: Finola C
authors.initials: FC
authors.lastname: Leonard
authors.affiliation: Teagasc, Pig Development Department, Animal and Grassland Research and Innovation Centre, Moorepark, Fermoy, Co. Cork, Ireland.
authors.forename: Peadar G
authors.initials: PG
authors.lastname: Lawlor
authors.affiliation: Department of Science, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Gillian E
authors.initials: GE
authors.lastname: Gardiner
authors.affiliation: Teagasc, Food Research Centre, Ashtown, Dublin 15, Ireland. Electronic address: Geraldine.Duffy@teagasc.ie.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Duffy
mesh_terms: D000003:Abattoirs; D000818:Animals; D003902:Detergents; D004202:Disinfectants / Q000737:chemistry*; D004203:Disinfection / Q000379:methods*; D004755:Enterobacteriaceae / Q000302:isolation & purification*; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000517:prevention & control*; D006920:Hygiene; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012475:Salmonella / Q000302:isolation & purification*; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000517:prevention & control*; D012703:Serotyping; D012973:Sodium Hypochlorite; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000382:microbiology
chemical_list: D003902:Detergents; D004202:Disinfectants; D000644:Quaternary Ammonium Compounds; D012973:Sodium Hypochlorite
keywords: Chlorocresol; Drying; Eliminate; Lairage; Quaternary ammonium compound