Variability of Escherichia coli and Enterobacteriaceae counts on pig carcasses: A systematic review

BackgroundIndicator bacteria are considered an interesting target for microbiological analysis in order to obtain information about the hygiene of processes and products. Quantitative analysis targeting indicator bacteria offers several advantages over pathogenic bacteria since indicator bacteria prevalence and counts are higher, and their distribution is more homogeneous, than pathogens. However, although microbiological criteria addressing indicator bacteria are already in place in industrialised countries such as the EU and US, information on factors affecting their counts on carcasses at slaughter is scattered.ObjectivesThe aim of this review was to provide valuable information about the variability of indicator bacteria along the pig slaughterline, and to suggest suitable means for the implementation of GMP (Good Manufacturing Practices) and process hygiene in pig slaughterhouses.ConclusionsAlong the slaughterline, scalding and chilling stages effectively reduce both Escherichia coli and Enterobacteriaceae counts on pig carcasses and have to be considered in the implementation of HACCP systems. Surface pasteurisation under experimental slaughter conditions was also effective; in contrast, washing did not reduce microbial contamination on pig carcasses. Evisceration was confirmed as a key contamination point, in particular regarding Enterobacteriaceae, but it has been suggested that bacterial load can be controlled by anal plugging if it is performed according to good manufacturing practices (GMP).     

Application of multivariate statistical analysis to quality control systems. Relevance of the stages in poultry meat production

The poultry meat production includes several stages. In this study, the whole process has been evaluated in order to determine the stages or processes which must be specially taken into account in the control system, and which other could be out of the routine controls. The study has been carried out in reverse by studying the relevance of every stages starting from the end of the process towards the initial point.A sequence of operations and consecutive statistical analyses has been performed to finally state the stages and/or operations that must be controlled.Based on the result of statistical studies, the plucking, gutting, washing and classifying stages should be considered Process Control Points. Air chilling and packaging stages are not considered checkpoints in the process verification system, although they should be included within the Good Hygiene Practices, since factors such as temperature, time, cleaning, disinfection or appropriate conditions of handling should be monitored.     

HACCP plan proposal for a typical Brazilian peanut processing company

Peanuts are likely to be infested by fungi with consequent contamination by aflatoxin in post-harvest industries. A hazard analysis critical control point (HACCP) plan is proposed for a typical Brazilian post-harvest industry from raw in-shell reception to the unpeeled peanuts transportation. Codex Alimentarius Commission guidelines were followed, with four critical control points (CCP) for aflatoxin being identified. The process steps with highest probability of aflatoxin occurrence (risk) are the in-shell reception, the dried in-shell storage, and the unpeeled kernel storage. During the storage steps there is a lack of control of air moisture and temperature. Therefore, there is no option but to keep rigid monitoring and control over each CCP, and detour lots with high aflatoxin levels to either oil or seed production. Attempts to correlate the aflatoxin levels with the rainfall showed an irregular trend of the toxin level.     

On-line real time aid to the verification of CCP compliance in beef slaughter HACCP systems

This study investigated the use of an on-line monitoring and display system in a beef slaughtering plant. The objective was to determine what information was possible and what benefits could be forthcoming that would assist compliance with HACCP requirements. The system was to be low tech, user friendly and economical. The study was carried out over eleven days, spread over 13 weeks; 75 cattle were observed each day for visible faecal, rumen and ingesta contamination over six sites per carcass side. Spinal cord presence in the exposed spinal channel was also observed. Over the course of the study the number of carcasses with visible contaminated was reduced from 76% to 33.33%; visible contamination attributed to dehiding operations was reduced from 54.67% to 24.00%, visible contamination attributed to evisceration operations was reduced from 44% to 16.67%. A significant reduction in the magnitude of visible contamination per carcass was also observed. Spinal cord presence was reduced from 6% to 0%. The system facilitated the identification of the most probable causative process stages, the implementation of on-line real time immediate and long term corrective action and the establishment of a single process CCP.     

Escherichia coli and Enterobacteriaceae counts on poultry carcasses along the slaughterline: A systematic review and meta-analysis

BackgroundThe slaughtering process consists of a highly coordinated system of different operations and is of critical importance for meat hygiene. The evaluation of the impact of different stages on bacterial counts is useful to monitor carcass contamination and to improve the hygiene of different stages. Escherichia coli and Enterobacteriaceae are considered an interesting target for microbiological analysis.ObjectivesThe aim of this review was to summarize literature data about the influence of slaughter stage on E. coli and Enterobacteriaceae counts along the poultry slaughterline.ResultsSystematic review of the available literature and the meta-analysis of the data collected revealed that scalding resulted in a significant reduction of E. coli counts. Washing and chilling were able to decrease E. coli counts in a statistically significant way; however, the observed reductions were of no practical importance. Enterobacteriaceae were reduced only by defeathering and washing but no practical significance was observed. None of the other stages of the slaughterline resulted in significant changes of indicator bacteria counts.Conclusions and implicationsInformation provided would be useful to suggest suitable ways for the implementation of processes hygiene in poultry slaughterhouses in particular GMP (Good Manufacturing Practices) and HACCP through the identification of suitable CCPs.     

Prevalence of Listeria spp. at a poultry processing plant in Brazil and a phage test for rapid confirmation of suspect colonies

Sites and occurrence of Listeria contamination in an industrial poultry processing plant were investigated by sampling carcasses at varying stages of processing and testing the hands and gloves of food handlers as well as the chilling water used in the process. In the course of nine visits to a local processing plant we collected a total of 121 samples: 66 from carcasses, 37 from workers' hands and gloves and 18 from the water used for chilling. Except for the water samples Listeria was isolated at all sampling sites. The species most often isolated was Listeria innocua, which accounted for 28 of the 31 (90.3%) isolates. The frequency of Listeria in the chicken carcasses was similar at bleeding, defeathering and end of evisceration stages (33.3%), reduced during scalding (16.7%), and rose immediately after initial evisceration stage (50%) to peak after packaging (76.2%). The carcasses were contaminated by L. monocytogenes serotypes 1b and 1c only during packaging. The prevalence of Listeria spp. on workers' hands and gloves was 46% mostly with L. innocua (40.5%) followed by L. monocytogenes 1b (11.8%). Chilling water presented more than 100 ppm of chlorine, which could explain why the samples were negative to Listeria. As the contamination by Listeria in the carcasses progressively rose both in number, species and strains during processing it seems reasonable to conclude that those carcasses become contaminated at the processing level. Improvement and innovation measures to control bacteria in general at the processing plant level are necessary to effectively reduce final product contamination by L. monocytogenes. In the course of this work we introduced a bacteriophage susceptibility test to confirm suspected Listeria colonies which was able to reduce the time of analysis to a minimum of 30 h depending on the isolation technique employed.     

Monitoring the microbiological quality of raw milk through the use of an ATP bioluminescence method

Microbiological control of raw milk quality at the dairy plant is an important step before appropriate decisions concerning the milk processing can be made. This step is therefore considered a CCP in the HACCP plans. Under the European Union (EU) law, 10⁵ bacteria ml⁻¹ at this point of the process are the critical limit enforced through the Directive 92/46 EEC. In the present work, the authors propose shifting the monitoring from procedures based only in temperature measurement to direct microbial count in milk using an ATP bioluminescence method, thus improving compliance at the CCP mentioned.     

An assessment of the microbial quality of the air within a pork processing plant

The aim of this study was to assess microbial quality of the air in a pork processing plant and from visual inspection to identify factors which may contribute to increase/decrease air-borne contamination. Total viable count (TVC), total coliform count (TCC) and the presence of Staphylococcus, Listeria and Salmonella species were used to evaluate the microbial quality of the air at five locations in the plant, at five time points during production. A visual inspection was used to identify risk factors which may increase the micro flora of the air in the plant. The highest TVC (133 cfu m⁻³), coliform counts (8 cfu m⁻³) and Staphylococcus aureus counts (8 cfu m⁻³) were found in the cooking area, blast chill and raw areas respectively. The higher levels of TVC, coliforms and Staphylococcus could most likely be attributed to people in the area, condensation and mechanically generated aerosol respectively although factors such as psychrometric properties of air and building ventilation factors which were outside of the scope of the current investigation would also need to be considered before a definite conclusion could be made in this regard. Listeria and Salmonella were not detected in the air in the plant. However, the inspection suggested the air in the raw area to be most at risk of microbial contamination, due to higher levels of microbial sources. Overall, microbial levels in the air were low, which suggests that the current control measures such as the positive air pressures from high-risk to low-risk, internal separators and closed drains were effective in reducing the microbial contamination in the air of the plant.     

Antibacterial activity of decontamination treatments for cattle hides and beef carcasses

There is increasing interest in effective decontamination treatments because healthy food-producing animals can harbor food-borne pathogens and complete prevention of contamination during slaughter can hardly be warranted. Thus we reviewed the available literature and appraised the antibacterial activity of physical, chemical and biological interventions applied on cattle hides and beef carcasses. Based on the evaluated studies, the efficacy of water sprayings, organic acids and their combinations was most frequently investigated for the decontamination of cattle hides and beef carcasses. Most data originated from laboratory-based studies using inoculated samples and extrapolation of these results to commercial practices is restricted. Application of interventions at slaughter plants reduced the bacterial loads on hides and carcasses to some extent, but reductions were clearly lower than those obtained under laboratory conditions. Thus hot water, steam, acetic acid or lactic acid treatment mainly yielded bacterial reductions below two orders of magnitude on carcasses. Under commercial conditions, the use of multiple sequential interventions at different points during slaughter must also be considered in order to enhance the microbiological safety of carcasses. On the other hand, decontamination treatments always must be considered part of an integral food safety system.     

HACCP does not work from Farm to Table

Because of its inability to detect hazards that occur a low incidence, the quality control system was supplanted by the HACCP system to provide assurance of food safety. The global use and success of the HACCP system in the food processing industry created false expectations that it could be used successfully in all steps of the food supply chain, from Farm to Table. However, the lack of definitive critical control points that could eliminate or control identified hazards prevents the effective use of HACCP in all steps of the supply chain. Food safety measures can be used at each step in the supply chain, but most of these measures will be prerequisite programs rather that critical control points from a HACCP system. To better focus on the application of effective food safety control measures, we must communicate in terms of “Farm to Table Food Safety”, rather than “Farm to Table HACCP”.     

Validation of parameters in HACCP verification using univariate and multivariate statistics. Application to the final phases of poultry meat production

For Hazard Analysis and Critical Control Points (HACCP) systems verification in food industries, the selection of parameters that offer significant information about control system at each production stages is necessary. Total Count (TC), Pseudomonas (PS), Enterobacteriaceae (EB) and Staphylococcus aureus (ST) are organisms frequently measured on carcasses at slaughters. Their inclusion in HACCP system can be assessed by means of statistical techniques. Univariate and multivariate statistical methods are of great importance in order to identify most useful variables. In this study the use of these microbiological parameters in verification of refrigeration, and cutup and packaging operations has been evaluated. It has established the usefulness of these variables using statistical techniques. It makes clear the most discriminant effect of EB and TC to establish differences between the stages studied in this process.     

Implementation of traceability and food safety systems (HACCP) under the ISO 22000:2005 standard in North Africa: The case study of an ice cream company in Algeria

Our study aims at establishing and implementing the HACCP and traceability system, in an integrated approach, of ice cream processing in order to control food borne safety hazards, to minimize the production and distribution of unsafe or poor quality products, thereby the potential food safety risks and associated food recalls. Internal information capture points were identified in ice cream process and the corresponding traceability information to be recorded were determined. Biological, physical, chemical and allergens hazards that could emerge at each stage of the production were identified. After hazards identification, the critical control points (CCPs) and operational prerequisites programs (oPRPs) were selected using a decision tree. Results showed that cleaning-in-place, filtration, pasteurization, cooling storage and transport stages were the critical control points identified. Critical limits, monitoring methods and frequency, responsibilities and corrective actions of the processes are also presented. Finally, the impact of implementation of food safety system (HACCP) on aerobic plate count (APC) and coliforms in vanilla, strawberry and chocolate flavoured ice cream was investigated. The results of HACCP adoption showed the reduction of APC in all flavours of the ice cream samples tested, being higher for the strawberry from 4.18 ± 3.03 till 3.80 ± 2.71 log CFU/g. Besides, a significant decrease of coliforms from 2.39 ± 1.76 till 2.11 ± 1.42 and 2.54 ± 1.62 till 2.02 ± 1.15 log CFU/g was observed in ice cream samples with a chocolate and strawberry flavour, respectively. In conclusion, the implementation of traceability and HACCP system, under the ISO 22000 standard has allowed tracking and tracing of ice cream products improving the microbiological quality of the ice creams.     

How to make HACCP really work in practice

A HACCP system that really works in practice will depend on the competency of the people who both developed it and who operate it, and the prerequisite programmes, which support it. If it is to be truly successful then there must be an overriding internal belief in the HACCP approach and what it can do for the business once properly implemented. There are fundamental issues concerning the Training and Education which need to be considered, such as the variable quality of education and training available on a global basis, impinge on the ability of HACCP teams to conduct a Hazard Analysis. Compounded with this is the general weak understanding of the HACCP and prerequisite programme relationship and of the implementation and maintenance phases … on how to make it really happen. These elements are considered against four key stages to the application of HACCP principles.     

Systematic review-meta-analysis of the effect of chilling on Campylobacter spp. during primary processing of broilers

Carcass chilling is a critical control point for Campylobacter spp. during the primary processing of broiler chickens. Our objective was to evaluate chilling intervention research that measured the change in Campylobacter prevalence and concentration on broiler chicken carcasses during primary processing using systematic review-meta-analysis (SR-MA) methodology. Experimental and observational research published in English that investigated impacts of chilling on Campylobacter spp. during primary processing of broiler chicken carcasses were considered. Random-effects MA of air chilling resulted in heterogenous summary effect estimates (mean reduction = 0.74 log₁₀ CFU/carcass, 95% CI: 0.32–1.17, I² = 91.3%; and odds ratio = 7.42, 95% CI: 0.32–174.05, I² = 92.3%). Random-effects MA of immersion chilling with chlorine resulted in heterogenous summary effect estimates (mean reduction = 1.74 log₁₀ CFU/carcass, 95% CI: 1.32–2.16, I² = 86.4%; and odds ratio = 0.50, 95% CI: 0.20–1.28, I² = 90.6%). Effects of immersion chilling with unspecified disinfectants were also determined and varied depending on study design. The SR-MA indicated that air chilling and immersion chilling reduce Campylobacter concentrations. Due to conflicting results across studies, the estimated average effect of air chilling on Campylobacter prevalence is not informative. Immersion chilling with chlorine demonstrated a trend towards reduced Campylobacter prevalence, but this result was not significant; results should be interpreted with caution because the overall methodological soundness of included studies was low. Existing research on the effectiveness of broiler carcass chilling on Campylobacter concentration or prevalence is limited and heterogenous. Results generated herein can inform decisions makers and stakeholders on potential effective chilling interventions, and can be used to inform quantitative microbial risk assessment to estimate processing measure impacts on public health.     

Improving microbiological food Safety in peri-urban Mali; an experimental study

IntroductionTwenty years ago, a WHO review of the literature assumed that most food-borne disease transmission in developing countries takes place within the home, and advocated a major programme of interdisciplinary research to develop and test cost-effective interventions to promote food hygiene.MethodsThe HACCP approach was applied step by step, to two selected weaning foods prepared by 15 volunteer mothers in peri-urban Mali. After setting Critical Control Points (CCP), actions were taken to control, reduce or eliminate microbial growth at these points. 432 food samples were collected and examined for thermotolerant coliforms in a local laboratory to assess the effectiveness of the approach. Lessons learnt were translated into messages delivered in a pilot study.ResultsTraditional cooking was very effective in eliminating faecal contamination; reheating was as effective as cooking when adopted, because there was no significant difference in the temperatures reached in both cases. Behavioural corrective actions were effective in controlling faecal contamination at the other CCPs (serving the child after cooking and after reheating).ConclusionIn conclusion, the HACCP experiment improved significantly the bacterial safety of both types of weaning food studied.     

PCR detection of Campylobacter sp. from turkey carcasses during processing plant in Iran

Turkey carcasses were sampled in one commercial poultry processing plant of Isfahan (Iran) to evaluate the contamination of carcasses to Campylobacter spp. along the processing plant by PCR method. A total of 348 samples were collected during six plants visit from May to December 2007. Campylobacter spp. were isolated from 62.1% (216 out of 348) of the samples. Out of 216 Campylobacter isolates, 175 (81.0%) were identified as Campylobacter jejuni and 41 (19.0%) as Campylobacter coli. The occurrences of Campylobacter spp. contamination after defeathering, evisceration and chilling were 75.9%, 77.6% and 32.8% respectively. The results indicate that the fecal recontamination of the avian skin occurred during defeathering and evisceration. However chilling process decreases Campylobacter spp. contamination of the turkey skin significantly.     

Antimicrobial activity of decontamination treatments for poultry carcasses: A literature survey

The decontamination of poultry carcasses is gaining increased interest in Europe, especially because poultry is implicated as a risk factor in human campylobacteriosis. Thus we appraised the antibacterial activity of interventions applied on poultry carcasses. Physical interventions included water-based treatments, irradiation, ultrasound, air chilling, or freezing. Especially hot water, steam, electrolyzed water (EW), and irradiation effectively reduced the bacterial load. Reductions obtained by hot water, steam, and EW mainly ranged from 0.9 to 2.1, 2.3 to 3.8, and 1.1 to 2.3 orders of magnitude, respectively. However, hot water or steam might exert an adverse impact on the carcass appearance. Chemical interventions primarily comprised organic acids, chlorine-based treatments, or phosphate-based treatments. Thereby, acetic and lactic acid, acidified sodium chlorite, and trisodium phosphate mainly yielded reductions in the range from 1.0 to 2.2 orders of magnitude. Besides, some combination treatments further enhanced the reductions. However, organic matter often reduces the antimicrobial activity of chemicals. Furthermore, biological interventions (e.g. bacteriophages) constitute promising alternatives, but further investigations are required. Although the mentioned interventions reduced the bacterial loads on poultry carcasses to some extent, decontamination treatments always must be considered part of an integral food safety system.     

Integrating statistical process control to monitor and improve carcasses quality in a poultry slaughterhouse implementing a HACCP system

In meat slaughterhouses, the enumeration of certain microorganisms as microbiological quality indicators is very important for verifying effectiveness of the Good Hygiene Practices (GHP) and Hazard Analysis Critical Control Points (HACCP) systems. Microbiological testing of final products as part of the HACCP verifying process may provide information that a process is in control. The aim of this work was to exploit the data from a poultry slaughterhouse implementing HACCP and demonstrate an alternative approach to the conventional statistical analysis using the principles of the Six Sigma quality. The data collected on Total Viable, Total Coliforms and Staphylococcus aureus counts were used to construct control charts (X bar–R control chart) and perform process capability analysis. Based on X bar–R control charts, the process was in a statistical control state but this before its automation was not capable since process capability and process performance indices were below 1.00, indicating the production of poultry carcasses with poor microbiological quality. After process automation, the indices were much higher than 2.00, indicating that the process was capable of producing poultry carcasses within the specification limits.     

Antibacterial activity of decontamination treatments for pig carcasses

Prevention or reduction of carcass contamination with food-borne pathogens during slaughter is of particular importance. Antimicrobial intervention technologies are therefore gaining increasing interest in the slaughter process. In this review, we screened the available recent literature on the decontamination of pig carcasses and appraised the antibacterial activity of treatments. Compared to poultry and beef carcasses, data on decontamination treatments for pig carcasses are so far limited and mainly physical and chemical interventions were investigated. Physical treatments were on the one hand part of the normal pig slaughter process. Dependent on time and temperature conditions, the bactericidal effect of scalding was shown in several studies, whereas the effect of singeing or chilling differed widely. On the other hand, interventions as hot water spraying, steam treatment or ultraviolet light were additionally applied with the specific objective of carcass decontamination. Hot water spraying and steam treatment thereby yielded bacterial reductions ranging from 1.0 to 2.1 orders of magnitude. Chemical interventions primary included lactic and acetic acid. Under commercial conditions, lactic acid treatment yielded bacterial reductions ranging from 0.2 to 1.0 orders of magnitude.     

Implementation of HACCP to large scale production line of Greek ouzo and brandy: a case study

The advanced technology of high speed operations and the large scale of incoming materials and components used for food and drink production often cause hazards for the product safety. These hazards can hardly be controlled by the use of classical quality control methods. The most secure and cost-effective method for controlling the possible product contamination or cross contamination, due to physical or chemical hazard during the production is the implementation of the Hazard Analysis of Critical Control Points (HACCP system), particularly, if the latter is a part of a total quality system (TQS). The following case study on the application of HACCP to ouzo and brandy production demonstrates how the hazards at the 6 Critical Control Points (CCPs) of the process are easily and effectively controlled through the implementation of HACCP.