Tracking of Salmonella through the Pork Slaughter Process

End of project reportTo help address the problem of salmonellosis in the Republic of Ireland (RoI), a national Salmonella control programme was introduced in 1997 with a view to reducing the prevalence of Salmonella in pigs on the farm and on pig carcasses. The primary objective of this present study was to determine the correlation between the Salmonella serological and bacteriological status of pigs presented for slaughter and the Salmonella status of pork cuts following slaughter, dressing and chilling. Two additional studies investigated the prevalence and numbers of Salmonella spp. in the boning halls of four commercial pork abattoirs and at retail level in butcher shops and supermarkets in the RoI. The results indicated that categorisation of pig herds on the basis of a historical serological test for Salmonella was not a good predictor of the bacteriological Salmonella status of individual pigs at time of slaughter. However, it is acknowledged that serological testing does help in giving a rough estimate of the overall Salmonella status of a pig herd. There was a linear correlation between prevalence of Salmonella in caecal contents and on pork cuts at factory level; therefore, if the number of herds presented for slaughter with high levels of Salmonella (category 3) was reduced, there would be less potential for contamination of the lairage, equipment etc. and so less likelihood of Salmonella contamination on pork. The impact of crosscontamination during transport, lairage, processing and distribution cannot be ignored and measures to diminish this would significantly reduce the dissemination of Salmonella in the chain and the consequent risk posed. A key finding was the considerable variation in the incidence of Salmonella on different sampling days and in different slaughter plants.National Development Plan 2007-201

Antibiotic Resistance in Foodborne Pathogens

Wide-spread antibiotic resistance among bacterial pathogens is now a serious public health issue and multi-antibiotic resistance has been reported in many foodborne pathogens including Salmonella and E. coli. A study to determine antibiotic resistance profiles of a range of Salmonella and Verocytotoxigenic E.coli (VTEC) isolated from Irish foods revealed significant levels of antibiotic resistance in the strains. S. typhimurium DT104 were multiantibiotic resistant with 97% resistant to 7 antibiotics. S. Dublin and S. Agona showed lower levels of antibiotic resistance. Antibiotic resistance among VTEC isolates was generally low but two isolates of E. coli O157:H7 from minced beef were shown to be multi-antibiotic resistant (8 to 10 antibiotics). Studies to determine the relationship between antibiotic resistance and tolerance to heat were conducted. The survival of Salmonella spp. with different antibiotic profiles (antibiotic sensitive, laboratory-developed antibiotic resistant mutants or multi-antibiotic resistant) on chicken heated to 55ºC with or without a prior heat shock at 48ºC was established. The D value (time in minutes to achieve a 90% or 1 log reduction in the Salmonella population) recorded for a multi-antibiotic resistant S. Typhimurium DT104 was significantly higher (P\u3c0.05) than for all other strains tested (antibiotic sensitive or with laboratory-acquired antibiotic resistance). These results suggest that the presence of multi-antibiotic resistance genes increased the heat tolerance of Salmonella. The survival of VTEC, E. coli O157:H7 and E. coli O26 (antibiotic sensitive, laboratory-developed antibiotic resistant mutants or multi-antibiotic resistant) in minced beef heated to 55ºC with or without a prior heat shock at 48ºC was established. The D value recorded for multi-antibiotic resistant E. coli O157:H7 was significantly lower than for the other strains tested. These results indicate that the presence of multi-antibiotic resistant genes rendered the pathogens more sensitive to heat. Studies to determine whether antibiotic resistance could be transferred within species (Salmonella Typhimurium to Salmonella Agona) and between species (Salmonella to E. coli) when co-inoculated into laboratory media, milk or minced beef at different storage temperatures (37, 25, 15 and 4ºC) showed that horizontal antibiotic resistance gene transfer occurred in all substrates at temperatures of 37 and 25ºC. At 15ºC, transfer of resistance occurred only in minced meat. Similar results were reported for transfer of antibiotic resistance both within the Salmonella spp. and between different species (Salmonella to E. coli)

Letter from Thomas Duffy, New York State Special Prosecutor, to Geraldine Ferraro

Congratulatory letter from Thomas A. Duffy, New York State Special Prosecutor, to Geraldine Ferraro. Includes standard response letter from Ferraro.https://ir.lawnet.fordham.edu/vice_presidential_campaign_correspondence_1984_new_york/1213/thumbnail.jp

Investigation of the Causes of Shigatoxigenic Escherichia coli PCR Positive and Culture Negative Samples

peer-reviewedMolecular methods may reveal the presence of pathogens in samples through the detection of specific target gene(s) associated with microorganisms, but often, the subsequent cultural isolation of the pathogen is not possible. This discrepancy may be related to low concentration of the cells, presence of dead cells, competitive microflora, injured cells and cells in a viable but non-culturable state, free DNA and the presence of free bacteriophages which can carry the target gene causing the PCR-positive/culture-negative results. Shiga-toxigenic Escherichia coli (STEC) was used as a model for studying this phenomenon, based on the phage-encoded cytotoxins genes (Stx family) as the detection target in samples through real-time qPCR. Stx phages can be integrated in the STEC chromosome or can be isolated as free particles in the environment. In this study, a combination of PCR with culturing was used for investigating the presence of the stx1 and stx2 genes in 155 ovine recto-anal junction swab samples (method (a)-PCR). Samples which were PCR-positive and culture-negative were subjected to additional analyses including detection of dead STEC cells (method (b)-PCR-PMA dye assay), presence of Stx phages (method (c)-plaque assays) and inducible integrated phages (method (d)-phage induction). Method (a) showed that even though 121 samples gave a PCR-positive result (78%), only 68 samples yielded a culturable isolate (43.9%). Among the 53 (34.2%) PCR-positive/culture-negative samples, 21 (39.6%) samples were shown to have STEC dead cells only, eight (15.1%) had a combination of dead cells and inducible stx phage, while two samples (3.8%) had a combination of dead cells, inducible phage and free stx phage, and a further two samples had Stx1 free phages only (3.8%). It was thus possible to reduce the samples with no explanation to 20 (37.7% of 53 samples), representing a further step towards an improved understanding of the STEC PCR-positive/culture-negative phenomenon

Investigation of accessibility of electronic music resources for the visually impaired

The number of students at Western Michigan University (WMU) who require accommodation for disabilities has been increasing in recent years, and is expected to continue to increase in the future. While the University Libraries tries to be responsive to all types of accommodations, students with visual impairments present a particular challenge for libraries to ensure their electronic resources are accessible. Most visually impaired students utilize “screen readers,” software programs that use a speech synthesizer to “read” the text that is displayed on the screen, to navigate web based resources. In an effort to try to better understand how specific screen readers work with our library electronic resources we employed a visually impaired student who is a sophisticated user of screen readers to test our electronic resources.Using a combination of browsers and operating systems, we used Job Access With Speech (JAWS), the most widely used screen reader, and NonVisual Desktop Access (NVDA), an open source screen reader, to test our website, our discovery layer and selected music databases. Databases tested include Music Periodicals Database (ProQuest), RILM Abstracts of Music Literature (EBSCO), and Grove Music Online. As WMU Libraries uses the ExLibris Primo discovery product, our instance of Primo was also tested for accessibility. The presenters will share the findings of the screen reader testing, including a pre-recorded demonstration of a visually impaired student conducting searches with screen readers, and describe our experiences in investigating accessibility of our electronic resources for visually impaired students. Presenters will also make recommendations for improving electronic resources and library services, in general, to better meet the needs of visually impaired patrons

Comparative effect of different cooking methods on the physicochemical and sensory characteristics of high pressure processed marinated pork chops

peer-reviewedThe objective of this study was to assess the effect of griddle and steam cooking on the physicochemical and sensory characteristics of high pressure processed (HPP) piri-piri marinated pork chops (MPC). Raw MPC that were HPP at 400 MPa had higher (P < 0.05) marinade absorption compared to untreated samples. After cooking, griddled MPC were significantly (P < 0.05) darker, less red, less yellow, tougher and had higher cook loss compared to steam cooked samples. The appearance of the griddled MPC was preferred while the texture, tenderness, juiciness and overall sensory acceptability (OSA) were preferred in steam cooked MPC. The increased marinade absorption in MPC that were HPP modified the fatty acid composition resulting in increased (P < 0.05) levels of oleic acid (C18:1c). Steam cooked MPC had a lower (P < 0.05) n-6: n-3 PUFA ratio and were preferred by the sensory panel compared to griddled MPC. Overall, from the cooking methods assessed steam cooking was the best cooking method for untreated and MPC that were HPP. Industrial relevance: Processed meat manufacturers are constantly looking for new ways to increase yield, safety and shelf life of meat products. While high pressure processing (HPP) of raw meat has been shown to increase the safety and shelf life of these products; however, negative effects on the physicochemical characteristics of raw meat products have been reported. For example, HPP of raw meat products causes a whitening effect which may negatively affect consumers' acceptance of these products. In this study, we used a novel approach (a combination of HPP, marinade and a mix of organic acids Inbac™) which showed great potential not only for enhancing the yield of marinated pork chops but also enhancement of the sensory properties, safety and shelf life and particularly the piri-piri marinade masked the discoloration of raw pork meat caused by HPP. This study also provides consumers, retailers and caterers with information on how to best prepare HPP meat products and showed that steam cooked HPP marinated pork chops had the best physicochemical and sensory characteristics compared to griddled marinated pork chops

Transfer of Ampicillin resistance from S. Typhimurium DT104 to E. coli K12 in food

Aims:  To investigate the transfer of antibiotic resistance from a donor Salmonella Typhimurium DT104 strain to a recipient Escherichia coli K12 strain. Methods and Results:  Mating experiments were conducted in broth, milk and ground meat (beef) at incubation temperatures of 4, 15, 25 and 37°C for 18 and 36 h. Ampicillin-resistance transfer was observed at similar frequencies in all transfer media at 25 and 37°C (10−4 to 10−5 log10 CFU ml g−1, transconjugants per recipient) for 18 h. At 15°C, transfer was observed in ground meat in the recipient strain (10−6, log10 CFU g−1, transconjugants per recipient), but not in broth or milk. At 4°C, transfer did not occur in any of the examined mediums. Further analysis of the E. coli K12 nalR transconjugant strain revealed the presence of a newly acquired plasmid (21 kbp) bearing the β-lactamase gene blaTEM. Transconjugants isolated on the basis of resistance to ampicillin did not acquire any other resistant markers. Conclusion:  This study demonstrates the transfer of antibiotic resistance in food matrices at mid-range temperatures. Significance and Impact of the Study:  It highlights the involvement of food matrices in the dissemination of antibiotic-resistant genes and the evolution of antibiotic-resistant bacteria

Antimicrobial Resistance in Irish isolates of Verocytotoxigenic Escherichia coli (E. coli)-VTEC.

This study compared the antimicrobial resistance profiles of Escherichia coli O157:H7 isolates (n = 257) recovered from bovine hides, minced beef and human clinical samples in Ireland, to those profiles of a range of Irish non-O157 E. coli (O111 and O26) isolates (n=31) from a variety of clinical and veterinary sources. Four multi-drug resistant (MDR) E. coli O157:H7 food isolates were identified, with resistance to 10 (1 isolate), 6 (1 isolate) and 4 (2 isolates) antimicrobial agents respectively. Two of these isolates (resistant to 7 and 4 antimicrobial classes) were characterised further by molecular methods and found to contain class 1 integrons along with a -lactamase-encoding tem-1 gene. Transfer of antimicrobial resistance (ampicillin, streptomycin and sulphonamides), the tem-1 gene and markers (int1, qacE1, sul1) characteristic of class 1 integrons were evident in one MDR isolate (resistant to 4 antimicrobial classes) when conjugation and transformation experiments were performed. A clinical isolate and a veterinary isolate of the O111 serotype were MDR and resistant to 4 and 3 antimicrobial classes respectively. These data suggests that the prevalence of antimicrobial resistance among the three VTEC serotypes examined in this study is low. These organisms may become a public health risk should they enter the food chain

Emerging Technologies for Aerial Decontamination of Food Storage Environments to Eliminate Microbial Cross-Contamination

peer-reviewedAir is recognized as an important source of microbial contamination in food production facilities and has the potential to contaminate the food product causing food safety and spoilage issues for the food industry. Potential for aerial microbial contamination of food can be a particular issue during storage in cold rooms when the food is not packaged and is exposed to contaminated air over a prolonged period. Thus, there are potential benefits for the food industry for an aerial decontamination in cold storage facilities. In this paper, aerial decontamination approaches are reviewed and challenges encountered for their applications are discussed. It is considered that current systems may not be completely e ective and environmentally friendly, therefore, it is of great significance to consider the development of nonresidual and verified decontamination technologies for the food industry and, in particular, for the cold storage rooms

Epidemiological indicators for meat inspection of bovine animals

n/