Effect of simulated spray chilling with chemical solutions on acid-habituated and non-acid-habituated Escherichia coli O157:H7 cells attached to beef carcass tissue.

Samples (10 by 20 by 2.5 cm) of beef carcass tissue were inoculated (10(4) to 10(5) CFU/cm2) with Escherichia coli O157: H7 that was either non-acid habituated (prepared by incubating at 15 degrees C for 48 h in inoculated filter-sterilized composite [1:1] of hot and cold water meat decontamination runoff fluids, pH 6.05) or acid habituated (prepared in inoculated water fluids mixed with filter-sterilized 2% lactic acid [LA] runoff fluids in a proportion of 1/99 [vol/vol], pH 4.12). The inoculated surfaces were exposed to conditions simulating carcass chilling (- 3 degrees C for 10 h followed by 38 h at 1 degree C). Treatments applied to samples (between 0 and 10 h) during chilling included the following: (i) no spraying (NT) or spraying (for 30 s every 30 min) with (ii) water, (iii) cetylpyridinium chloride (CPC; 0.1 or 0.5%), (iv) ammonium hydroxide (AH; 0.05%), (v) lactic acid (LA; 2%), (vi) acidified sodium chlorite (ASC; 0.12%), (vii) peroxyacetic acid (PAA; 0.02%), (viii) sodium hydroxide (SH; 0.01%), or (ix) sodium hypochlorite (SC; 0.005%) solutions of 4 degrees C. Samples were taken at 0, 10, 24, 36, and 48 h of the chilling process to determine changes in E. coli O157:H7 populations. Phase 1 tested water, SH, PAA, LA, and 0.5% CPC on meat inoculated with non-acid-habituated pathogen populations, whereas phase 2 tested water, SC, AH, ASC, LA, and 0.1% CPC on meat inoculated with acid- and non-acid-habituated populations. Reductions in non-acid-habituated E. coli O157:H7 populations from phase 1 increased in the order NT = water = SH < PAA < LA < CPC. Reductions from phase 2 for acid-habituated cells increased in the order NT = water = SC < ASC = LA = AH < CPC, whereas on non-acid-habituated cells the order observed was NT = water = SC < AH = ASC < LA < CPC. Previous acid habituation of E. coli O157:H7 inocula rendered the cells more resistant to the effects of spray chilling, especially with acid; however, the trend of reduction remained spray chilling with water = non-spray chilling < spray chilling with chemical solutions.

[1]  J. Sofos,et al.  Influence of organic acid concentration on survival of Listeria monocytogenes and Escherichia coli 0157:H7 in beef carcass wash water and on model equipment surfaces , 2003 .

[2]  J. Sofos,et al.  Influence of extended acid stressing in fresh beef decontamination runoff fluids on sanitizer resistance of acid-adapted Escherichia coli O157:H7 in biofilms. , 2003, Journal of food protection.

[3]  C. Gill,et al.  Effects of spray-cooling processes on the microbiological conditions of decontaminated beef carcasses. , 2003, Journal of food protection.

[4]  J. Sofos,et al.  Acid adaptation does not promote survival or growth of Listeria monocytogenes on fresh beef following acid and nonacid decontamination treatments. , 2003, Journal of food protection.

[5]  J. Sofos,et al.  Comparison of Intervention Technologies for Reducing Escherichia coli 0 157:H7 on Beef Cuts and Trimmings , 2003 .

[6]  J. Sofos,et al.  Strategies to Control Stress- Adapted Pathogens , 2002 .

[7]  J. Sofos,et al.  Biofilm formation by acid-adapted and nonadapted Listeria monocytogenes in fresh beef decontamination washings and its subsequent inactivation with sanitizers. , 2002, Journal of food protection.

[8]  T. Humphrey,et al.  The prevalence and number of Salmonella in sausages and their destruction by frying, grilling or barbecuing , 2002, Journal of applied microbiology.

[9]  J. Sofos,et al.  Exposure to non‐acid fresh meat decontamination washing fluids sensitizes Escherichia coli O157:H7 to organic acids , 2002, Letters in applied microbiology.

[10]  J. Sofos,et al.  Effect of acid adaptation on survival of Escherichia coli O157:H7 in meat decontamination washing fluids and potential effects of organic acid interventions on the microbial ecology of the meat plant environment. , 2002, Journal of food protection.

[11]  M. Uyttendaele,et al.  Effect of acid resistance of Escherichia coli O157:H7 on efficacy of buffered lactic acid to decontaminate chilled beef tissue and effect of modified atmosphere packaging on survival of Escherichia coli O157:H7 on red meat. , 2001, Journal of food protection.

[12]  J. Sofos,et al.  Fate of Escherichia coli O157:H7, Salmonella typhimurium DT 104, and Listeria monocytogenes in fresh meat decontamination fluids at 4 and 10 degrees C. , 2001, Journal of food protection.

[13]  J. Sofos,et al.  Influence of the Natural Microbial Flora on the Acid Tolerance Response of Listeria monocytogenes in a Model System of Fresh Meat Decontamination Fluids , 2001, Applied and Environmental Microbiology.

[14]  A. Castillo,et al.  Lactic acid sprays reduce bacterial pathogens on cold beef carcass surfaces and in subsequently produced ground beef. , 2001, Journal of food protection.

[15]  J. O. Reagan,et al.  Microbial populations on animal hides and beef carcasses at different stages of slaughter in plants employing multiple-sequential interventions for decontamination. , 2000, Journal of food protection.

[16]  C. Cutter,et al.  Antimicrobial activity of cetylpyridinium chloride washes against pathogenic bacteria on beef surfaces. , 2000, Journal of food protection.

[17]  A. Castillo,et al.  Reduction of Escherichia coli O157:H7 and Salmonella typhimurium on beef carcass surfaces using acidified sodium chlorite. , 1999, Journal of food protection.

[18]  J. Sofos,et al.  Nonacid meat decontamination technologies: model studies and commercial applications. , 1998, International journal of food microbiology.

[19]  J. Savell,et al.  Comparison of water wash, trimming, and combined hot water and lactic acid treatments for reducing bacteria of fecal origin on beef carcasses. , 1998, Journal of food protection.

[20]  C. Gill Microbiological contamination of meat during slaughter and butchering of cattle, sheep and pigs , 1998 .

[21]  C. Gill,et al.  Assessment of the hygienic performances of two beef carcass cooling processes from product temperature history data or enumeration of bacteria on carcass surfaces , 1997 .

[22]  D. E. Conner,et al.  Effects of Acetic-Lactic Acid Treatments Applied to Beef Trim on Populations of Escherichia coli O157:H7 and Listeria monocytogenes in Ground Beef †. , 1997, Journal of food protection.

[23]  C. Cutter,et al.  Effects of Steam-Vacuuming and Hot Water Spray Wash on the Microflora of Refrigerated Beef Carcass Surface Tissue Inoculated with Escherichia coli O157:H7, Listeria innocua , and Clostridium sporogenes †. , 1997, Journal of food protection.

[24]  R. Buchanan,et al.  Culturing enterohemorrhagic Escherichia coli in the presence and absence of glucose as a simple means of evaluating the acid tolerance of stationary-phase cells , 1996, Applied and environmental microbiology.

[25]  W. Jones,et al.  Use of Organic Acids To Improve the Chemical, Physical, and Microbial Attributes of Beef Strip Loins Stored at -1°C for 112 Days ‡. , 1996, Journal of food protection.

[26]  M. Slavik,et al.  Cetylpyridinium chloride (CPC) treatment on poultry skin to reduce attached Salmonella. , 1996, Journal of food protection.

[27]  J. Savell,et al.  Comparison of Methods for Decontamination from Beef Carcass Surfaces. , 1995, Journal of food protection.

[28]  M. E. Anderson,et al.  Microbiological Decontamination of Food Animal Carcasses by Washing and Sanitizing Systems: A Review. , 1992, Journal of food protection.

[29]  James S. Dickson,et al.  Control of Salmonella typhimurium, Listeria monocytogenes, and Escherichia coli 0157:H7 on Beef in a Model Spray Chilling System , 1991 .

[30]  J. Frank,et al.  Surface-adherent Growth of Listeria monocytogenes is Associated with Increased Resistance to Surfactant Sanitizers and Heat. , 1990, Journal of food protection.

[31]  H R Cross,et al.  Spray-chilling and carcass decontamination systems using lactic and acetic acid. , 1987, Meat science.