• Control and detection of food-borne pathogens

      Duffy, Geraldine; Cloak, Orla; Sheridan, James J.; Department of Agriculture, Food and the Marine, Ireland (Teagasc, Ballsbridge, Dublin 4, 1998-08)
      The objective of this study was to develop rapid methods for the detection of bacteria from food.
    • Control of Blown Pack Spoilage in Vacuum Packaged Meat

      Bolton, Declan; Moschonas, Galatios; Sheridan, James J.; Downey, Gerard; National Development Plan (Teagasc, 01/10/2009)
      Blown pack spoilage (BPS) represents a significant commercial loss to Irish meat processors. This research discovered that the organisms causing BPS are ubiquitous in the abattoir environment, making eradication very difficult. The risk of BPS is best managed through a process of regular treatment of plant and equipment with a sporicidal agent such as peroxyacetic acid, good hygiene to minimise carcass contamination and removal of the heat shrinkage stage during vacuum packaging as this activates the spores and reduces the time to spoilage.
    • Control of escherichia coli 0157:H7 in beefburgers

      Bolton, Declan; Byrne, Catriona; Catarame, Terese; Sheridan, James J. (Teagasc, 2001-04)
      The inactivation of E. coli O157:H7 by heating, freezing, pulsed electric field, sodium lactate, lactic acid and citric acid, alone or in combination was investigated. The industrial process for beefburger manufacture did not significantly reduce E.coli O157:H7 numbers regardless of the burger recipe and method of tempering used. Fast freezing of the burgers (to -18°C in 30 minutes as opposed to 36 hours), pulsed electric field, sodium lactate, lactic acid and citric acid, individually and in combination, did not significantly reduce E. coli O157:H7 numbers when applied at different stages throughout the beef burger manufacturing process. Beefburger safety is therefore reliant on proper storage, handling and thermal processing in the domestic or catering kitchen. The lethal effect of thermal processing may be enhanced by the addition of sodium lactate to the burger during mixing. These results are presented and discussed.
    • Development of a critical control step for E.coli 0157:H7 in pepperoni

      Duffy, Geraldine; Riordan, Denise C.; Sheridan, James J.; US-Ireland Co-operation Programme in Agriculture Science and Technology (Teagasc, 1999-10)
      Verocytotoxin producing Escherichia coli (VTEC) and particularly strains of serogroup O157, have emerged as food poisoning pathogens which can cause a severe and potentially fatal illness. The symptoms of VTEC infection include haemorrhagic colitis with bloody diarrhoea and severe abdominal pain. The infection may lead to renal failure as a result of haemolytic uraemic syndrome. Because of the severity of the illness and the low infectious dose, this pathogen is classed as a serious food safety issue. It is recommended by the United States Department of Agriculture that the production process for ready to eat foods such as fermented meats (pepperoni, salami etc.) should be capable of addressing a worst case scenario ie. the production process should be able to yield a log105.0cfu /g (105 cfu/g) reduction in numbers of E. coli O157:H7 on the raw meat. The aim of this study was to develop an industrially viable critical control step(s) which could be implemented into the pepperoni production process.
    • Development of HACCP analysis systems for beef slaughter

      Doherty, Alice M.; McEvoy, John M.; Sheridan, James J.; McGuire, Liam; O'Sullivan, Marian; Department of Agriculture, Food and the Marine, Ireland (Teagasc, Ballsbridge, Dublin 4, 1999-01)
      The aim of this study was to establish the types and levels of bacterial contamination on beef carcasses slaughtered under commercial conditions. This information is necessary as baseline data for the implementation of a Hazard Analysis Critical Control Point (HACCP) plan in a meat factory. Samples were taken over a twelve month period from five carcass sites representing the fore and hind quarters of the carcass. These included the hock, bung, inside round, cranial back and brisket. The carcasses were sampled at different stages of dressing namely legging, hide removal, evisceration, carcass splitting, carcass washing and chilling (24 h later). Four meat cuts (inside round, outside round, chuck roll (cranial back) and brisket) were also sampled after boning. Counts were enumerated for the following groups of bacteria: total bacterial counts (25°C and 4°C); pseudomonad counts (25°C and 4°C); E nterobacteriaceae counts; E scherichia coli O157:H7 and L isteria spp.
    • Escherichia coli 0157:H7: implications for HACCP on the farm and in the abattoir

      Bolton, Declan; Byrne, Catriona; Sheridan, James J.; Riordan, Denise C.; European Union (Teagasc, 1999-01)
      Experiments were designed to assess the risks associated with Escherichia coli O157:H7 on the farm, through the abattoir and into the butcher shop. Data was also generated for application in model building and the reliability of pathogen models for predicting pathogen growth in different foods was examined.
    • A European study on animal food & biomedical aspects of E.coli 0157:H7

      Duffy, Geraldine; Garvey, Patricia; Sheridan, James J.; European Union; CT98-3935 (Teagasc, 2002-02)
      Verocytotoxin producing Escherichia coli (VTEC) and, in particular, strains of serogroup O157, have emerged as significant pathogens causing a range of severe and potentially fatal illnesses. The European Union has recognised the threat posed by E coli O157:H7 and the need to devise control strategies based on an understanding of VTEC pathogenicity, transmission, survival and growth. It acknowledges the importance of informing farmers, veterinarians, food producers and health authorities so that each of these groups can act appropriately to reduce the overall hazards posed by these organisms. To contribute to the development and dissemination of effective control strategies, the European Commission funded this Concerted Action Project 1
    • HACCP for Irish beef, pork and lamb slaughter

      Bolton, Declan; Sheridan, James J.; US-Ireland Co-operation Programme in Agriculture Science and Technology; Department of Agriculture, Food and the Marine, Ireland (Teagasc, 2002-02)
      It is generally accepted that HACCP principles should be incorporated into the food safety control systems in meat processing plants to better assure food safety. The objective of this project was to publish detailed HACCP slaughter documents for the Irish beef, pork and lamb processing industries. These would provide the necessary information and detail to facilitate the implementation of HACCP on the slaughter floor (from lairage to chilling) in Irish meat plants. To this end `HACCP for Irish Beef Slaughter' was published in October 2000, `HACCP for Irish Pork Slaughter' in December 2001 and `HACCP for Irish Lamb Slaughter' will be available early in 2002. These are non-generic, detailed documents which provide the scientific basis for establishing critical control points (CCP), critical limits, monitoring and corrective action procedures.
    • Hygiene and safety of Irish beef carcasses.

      Kerr, Marie; Sheridan, James J. (Teagasc, 2002-10)
      Investigations were carried out in a number of beef abattoirs in Ireland. Information was obtained on the hygienic status of the carcasses being produced and also on their safety, using the presence of Salmonella as an indicator. The data showed that, in general, the hygiene of the carcasses being produced was of a satisfactory quality and that faecal contamination was low, as indicated by the coliform and E. coli counts. The safety of the carcasses as indicated by the presence of Salmonella was considered to be a cause for concern. The level of contamination by this pathogen of 7.6% was considered to be high and requires investigation. The majority of the Salmonella present on carcasses was S. typhimurium DT104, which is resistant to a range of antibodies. The work was part of an EU project and some results are presented from other partners.
    • Indicator organisms to determine the use of chilling as a critical point in beef slaughter HACCP

      Prendergast, Deirdre M.; Sheridan, James J.; Downey, Gerard (Teagasc, 2008-11)
      During chilling, temperatures of carcass surfaces at different sites change over time as do other parameters such as water activity (aw), the structure of the muscle and other tissues, as the carcass enters rigor mortis. Many of these factors are known to have a major effect on cell survival and growth and must be considered in determining the influence of chilling on bacterial survival on carcass surfaces. This study aimed to determine if chilling could be used as a critical control point (CCP) in beef slaughter in relation to pathogens such as E. coli O157:H7 and L. monocytogenes, using E. coli and Listeria innocua as pathogen indicators. The present study was designed to determine the influence of (a) chilling at 10oC for 72 h on the survival of E. coli and (b) chilling at 4oC for 72 h on the survival of L. innocua inoculated at different sites on beef carcasses. Three sites (neck, outside round and brisket) were inoculated (1) immediately after dressing while hot (E. coli and L. innocua) and (2) when cold after chilling (L. innocua). The influence of changes in surface aw was also considered and their relationship to the survival of E. coli and L. innocua over time was assessed. The data are discussed in relation to the use of chilling as a CCP in beef hazard analysis (HACCP) and the monitoring of neck temperature as the most suitable CCP.
    • A nationwide surveillance study on E.coli 0157:H7 and enterobacteriaceae in Irish minced beef products

      Duffy, Geraldine; Cagney, Claire; Crowley, Helen; Sheridan, James J.; Food Safety Authority of Ireland (Teagasc, 2003-04)
      A surveillance study on prevalence and numbers of E . coli O157: H7 in minced beef (unpackaged or packaged) and beefburgers (frozen, fresh and unpackaged or packaged) was carried out over a period of 12 months in the Republic of Ireland. A total of 1533 products were tested with approximately 15 products collected from each of the 26 counties every 3 months. Mince and beefburgers were collected from both supermarkets and butcher shop outlets. A standard analysis was conducted by sample enrichment, IMS extraction and plating onto SMAC agar with confirmation by PCR. The results showed that 43 retail beef products (2.8 %) contained E .coli O157:H7. The number of E .coli O157: H7 in 21 of these samples ranged from log100.51 - 4.03 cfu g-1 ( i.e. 3 to 10,700 bacteria per gram) while in the remaining 22 the pathogen was detectable by enrichment only. There was a seasonal effect observed with 33 of 43 positive samples detected in January (n = 8), April /May(n=20) and August (n=5) and the remaining 10 positive samples detected over the other 8 months. Of the beef products testing positive, 32 were purchased from supermarkets and 11 from butcher shops. E .coli O157:H7 was recovered from 2.8% (13 / 457) of fresh packaged mince and from 1.88 % (3 / 160) of fresh unpackaged burgers purchased from butcher shops. Of the 43 isolates recovered, 41 contained the virulence genes v t1, v t2, E aeA and H lyA while the remaining 2 isolates contained only one of the vtproducing genes (v t1or v t2).
    • Risk-based determination of critical control points for pork slaughter

      Bolton, Declan; Pearce, Rachel; Sheridan, James J.; Department of Agriculture, Food and the Marine, Ireland (Teagasc, 2002-05)
      To identify the critical control points (CCPs) during commercial pork slaughter, 60 pigs in a small abattoir (80 pigs per day) and a similar number in a larger plant (2000 pigs per day) and/or their resultant carcasses were swabbed at the ham, belly and neck. The total bacterial contamination was determined after each stage from the live pigs on the farm to chilling of the carcasses in the abattoir.
    • Routine diagnostic tests for food-borne pathogens

      Duffy, Geraldine; Kilbride, Brendan; Fitzmaurice, Justine; Sheridan, James J. (Teagasc, 2001-01)
      Rapid techniques were developed and applied to the determination of total viable bacteria and to the detection of food borne pathogens (Listeria monocytogenes, Salmonella, Campylobacter jejuni and E. coli O157:H7). The method developed for total viable counts is based on membrane filtration and fluorescent staining and the technique can be performed and a result obtained within 20 min. The results correlate well with the standard plate count and the technique is now being implemented in Irish food factories.
    • Spread of brain and spinal cord material during beef slaughter

      Daly, Dyan J.; Prendergast, Deirdre M.; Sheridan, James J. (Teagasc, 2002-04)
      Emboli of brain tissue in the lungs have been reported in cases following severe head injury (McMillan 1956) and birth trauma in people (Hauck e t al 1990) and in cattle following stunning (Bauer 1996; Garland 1996). This has important implications for food safety if the brain tissue of stunned cattle is infected with the prion responsible for bovine spongiform encephalopathy (BSE), (Prusiner 1991). BSE emerged following changes in the rendering process in the early 1980s which allowed the aetiologic agent to survive, contaminate protein feed supplement and infect cattle (Brown e t al. 2001). Within a short period of time after the first case of BSE, concerns were expressed regarding the transmission of BSE to humans and the likelihood of infection from consumption of beef and beef products. This has become increasingly significant with the discovery of the link between BSE in cattle and variant Creutzfeldt-Jakob disease (vCJD) in man (Bruce e t al 1997).
    • A study of cryptosporidium parvum in beef

      Duffy, Geraldine; McEvoy, John M.; Moriarty, Elaine M.; Sheridan, James J.; European Union; QLK1 CT 1999 00775 (Teagasc, 2003-07)
      There is increasing concern that foods, particularly those of animal origin, may play a role in the transmission of C ryptosporidium parvum to humans. Studies were undertaken to examine the risk posed by C . parvum in the beef chain.
    • A study on the use of chilling as a critical control point in a beef HACCP plan.

      Kinsella, Kathleen; Sheridan, James J.; Rowe, T. (Teagasc, 2006-02)
      Investigations were undertaken to establish the critical limits for use of chilling in a Hazard Analysis Critical Control Point (HACCP) system for beef. Information was obtained on the influence of chilling on the survival of bacteria, including the pathogen Salmonella Typhimurium DT104, attached to beef carcass surfaces. In general, a chilling regime could not be identified that gave consistent and meaningful reductions in surface bacterial counts while not seriously compromising the quality of the carcasses in terms of excessive amounts of weight loss. The study concluded that chilling was not a satisfactory process for use as a critical control point (CCP) in beef chilling and could not be recommended to the Irish beef industry for inclusion in a HACCP plan.
    • The survival of added escherichia coli O157:H7 in natural mineral water and its products and the development of a rapid method for enumeration of the heterotrophic bacteria in natural mineral water

      Kerr, Marie; Fitzgerald, Margaret; Sheridan, James J. (Teagasc, 2000-12)
      The consumption of natural mineral water is rapidly growing and outpacing all other beverages on a global scale. In Europe, bottled water already has a bigger market share than carbonated soft drinks. Yet there is only a limited availability of information on the microbiological safety and quality of bottled natural mineral waters sold within the European Community. As natural mineral water does not receive any bacteriocidal treatment prior to bottling, the risk of pathogen contamination is a public health concern. Pathogen contamination may occur as a result of over exploitation of natural mineral water resources i.e. over abstraction by commercial bottling companies may lead to disturbance of the water table causing contaminated surface water to be drawn down into ground water supplies (Green and Green 1994). Such contamination was implicated in an outbreak of cholera associated with the consumption of bottled natural mineral water in Portugal in 1974 (Blake et al. 1977). The transport and dissemination of E. coli and enterococci in a limestone aquifer had been demonstrated by Personné et al. (1998), confirmation that E. coli can survive the transitory period from the surface to underground water supplies, thus raising the question of E. coli O157:H7 with its low infective dose < 10 cells (Willshaw et al. 1994 and Tilden et al. 1996) surviving the transitory period from surface to a natural mineral water aquifer.
    • The virulence of E. coli 0157:H7 isolated from Irish sheep and pigs to humans

      Lenahan, Mary; Sheridan, James J.; O'Brien, Stephen (Teagasc, 2008-02)
      Investigations were carried out at five sheep and five pig export abattoirs situated in the Republic of Ireland to determine the prevalence of E. coli O157:H7 in these animals at slaughter. This is the first study for the presence of E. coli O157:H7 on sheep and pigs to be carried out in Ireland. Faeces and pre- and post-chill carcass swabs were collected from pigs over a one year period between January and December 2004. Samples were collected from sheep over a 13-month period between February 2005 and February 2006. The pig study recovered E. coli O157:H7 from 0.24 % (n=4) of 1680 porcine samples while the sheep study isolated the pathogen from 2.1 % (n=33) of 1600 ovine samples. PCR analysis of E. coli O157:H7 isolates determined that they carried the virulence genes vt1, vt2, eaeA and hlyA typically associated with clinical illness in humans. The results presented indicate that Irish sheep and pigs are reservoirs for E. coli O157:H7 which may be potentially harmful to humans.