Microbiological safety of aged meat.

The impact of dry-ageing of beef and wet-ageing of beef, pork and lamb on microbiological hazards and spoilage bacteria was examined and current practices are described. As 'standard fresh' and wet-aged meat use similar processes these were differentiated based on duration. In addition to a description of the different stages, data were collated on key parameters (time, temperature, pH and aw) using a literature survey and questionnaires. The microbiological hazards that may be present in all aged meats included Shiga toxin-producing Escherichia coli (STEC), Salmonella spp., Staphylococcus aureus, Listeria monocytogenes, enterotoxigenic Yersinia spp., Campylobacter spp. and Clostridium spp. Moulds, such as Aspergillus spp. and Penicillium spp., may produce mycotoxins when conditions are favourable but may be prevented by ensuring a meat surface temperature of -0.5 to 3.0°C, with a relative humidity (RH) of 75-85% and an airflow of 0.2-0.5 m/s for up to 35 days. The main meat spoilage bacteria include Pseudomonas spp., Lactobacillus spp. Enterococcus spp., Weissella spp., Brochothrix spp., Leuconostoc spp., Lactobacillus spp., Shewanella spp. and Clostridium spp. Under current practices, the ageing of meat may have an impact on the load of microbiological hazards and spoilage bacteria as compared to standard fresh meat preparation. Ageing under defined and controlled conditions can achieve the same or lower loads of microbiological hazards and spoilage bacteria than the variable log10 increases predicted during standard fresh meat preparation. An approach was used to establish the conditions of time and temperature that would achieve similar or lower levels of L. monocytogenes and Yersinia enterocolitica (pork only) and lactic acid bacteria (representing spoilage bacteria) as compared to standard fresh meat. Finally, additional control activities were identified that would further assure the microbial safety of dry-aged beef, based on recommended best practice and the outputs of the equivalence assessment.

A European survey on post-mortem inspection of finishing pigs: Total condemnation criteria to declare meat unfit for human consumption.

Meat inspection (MI) is essential to verify compliance with legal requirements related to human and animal health and animal welfare protections. Judgement criteria applied during MI, resulting in condemnation data of importance, among other things, for livestock producers and for benchmarking reasons. However, although the Meat Inspection Regulation sets out judgement criteria, most are generic, favouring flexibility, but also subjectivity. To address the degree of variation on total condemnation (TC) criteria applied during post-mortem inspection (PMI) of finishing pigs, an online survey was prepared aiming to collect this information from several European countries. The focus was on TC criteria regarding the following PMI findings: abscesses, arthritis, cachexia, erysipelas, icterus, Mycobacterium-like lesions, osteomyelitis, peritonitis, pleuritis and pneumonia. From September to November 2020, a total of 44 completed questionnaires were obtained from 26 European countries. The results showed a substantial variation in the TC criteria in place in the participating countries. One of the main reasons for the variability seen in the respondents' reported answers was related to the indicators used to define a generalised condition related to the 10 PMI findings addressed, making harmonisation a challenge and avoiding to draw conclusions when comparing condemnation causes between abattoirs. This implies that it would make sense to look into how a generalised condition can be identified/described and how it should be judged. The results should be used as inspiration towards possible harmonisation, improving decision-making, and permitting comparative analysis between different reports to allow trend analyses and benchmarking.

Systematic Review and Meta-Analysis of the Efficacy of Interventions Applied during Primary Processing to Reduce Microbial Contamination on Pig Carcasses.

Interventions from lairage to the chilling stage of the pig slaughter process are important to reduce microbial contamination of carcasses. The aim of this systematic review and meta-analysis was to assess the effectiveness of abattoir interventions in reducing aerobic colony count (ACC), Enterobacteriaceae, generic Escherichia coli, and Yersinia spp. on pig carcasses. The database searches spanned a 30 year period from 1990 to 2021. Following a structured, predefined protocol, 22 articles, which were judged as having a low risk of bias, were used for detailed data extraction and meta-analysis. The meta-analysis included data on lairage interventions for live pigs, standard processing procedures for pig carcasses, prechilling interventions, multiple carcass interventions, and carcass chilling. Risk ratios (RRs) for prevalence studies and mean log differences (MDs) for concentration outcomes were calculated using random effects models. The meta-analysis found that scalding under commercial abattoir conditions effectively reduced the prevalence of Enterobacteriaceae (RR: 0.05, 95% CI: 0.02 to 0.12, I2 = 87%) and ACC (MD: -2.84, 95% CI: -3.50 to -2.18, I2 = 99%) on pig carcasses. Similarly, significant reductions of these two groups of bacteria on carcasses were also found after singeing (RR: 0.25, 95% CI: 0.14 to 0.44, I2 = 90% and MD: -1.95, 95% CI: -2.40 to -1.50, I2 = 96%, respectively). Rectum sealing effectively reduces the prevalence of Y. enterocolitica on pig carcasses (RR: 0.60, 95% CI: 0.41 to 0.89, I2 = 0%). Under commercial abattoir conditions, hot water washing significantly reduced ACC (MD: -1.32, 95% CI: -1.93 to -0.71, I2 = 93%) and generic E. coli counts (MD: -1.23, 95% CI: -1.89 to -0.57, I2 = 61%) on pig carcasses. Conventional dry chilling reduced Enterobacteriaceae prevalence on pig carcasses (RR: 0.32, 95% CI: 0.21 to 0.48, I2 = 81%). Multiple carcass interventions significantly reduced Enterobacteriaceae prevalence (RR: 0.11, 95% CI: 0.05 to 0.23, I2 = 94%) and ACC on carcasses (MD: -2.85, 95% CI: -3.33 to -2.37, I2 = 97%). The results clearly show that standard processing procedures of scalding and singeing and the hazard-based intervention of hot water washing are effective in reducing indicator bacteria on pig carcasses. The prevalence of Y. enterocolitica on pig carcasses was effectively reduced by the standard procedure of rectum sealing; nevertheless, this was the only intervention for Yersinia investigated under commercial conditions. High heterogeneity among studies and trials investigating interventions and overall lack of large, controlled trials conducted under commercial conditions suggest that more in-depth research is needed.

Prevalence and Persistence of Multidrug-Resistant Yersinia enterocolitica 4/O:3 in Tonsils of Slaughter Pigs from Different Housing Systems in Croatia.

Yersinia enterocolitica is one of the priority biological hazards in pork inspection. Persistence of the pathogen, including strains resistant to antimicrobials, should be evaluated in pigs from different housing systems for risk ranking of farms. In this 2019 study, tonsils were collected from 234 pigs, of which 69 (29.5%) were fattened on 3 big integrated farms, 130 (55.5%) on 10 medium-sized farms, and 35 (15%) on 13 small family farms. In addition, 92 pork cuts and minced meat samples from the same farms were tested for the presence of Y. enterocolitica using the culture method. Phenotypic and genetic characteristics of the isolates were compared with previously collected isolates from 2014. The overall prevalence of Y. enterocolitica in pig tonsils was 43% [95% CI 36.7−49.7]. In pigs from big integrated, medium-sized, and small family farms, the prevalence was 29%, 52%, and 40%, respectively. All retail samples of portioned and minced pork tested negative for pathogenic Y. enterocolitica, likely due to high hygienic standards in slaughterhouses/cutting meat or low sensitivity of culture methods in these matrices. The highest recovery rate of the pathogen from tonsils was found when alkali-treated PSB and CIN agar were combined. The biosecurity category of integrated and medium farms did not affect the differences in prevalence of Y. enterocolitica (p > 0.05), in contrast to family farms. Pathogenic ail-positive Y. enterocolitica biotype 4 serotype O:3 persisted in the tonsils of pigs regardless of the type of farm, slaughterhouse, and year of isolation 2014 and 2019. PFGE typing revealed the high genetic concordance (80.6 to 100%) of all the Y. enterocolitica 4/O:3 isolates. A statistically significant higher prevalence of multidrug-resistant Y. enterocolitica 4/O:3 isolates was detected in the tonsils of pigs from big integrated farms compared to the other farm types (p < 0.05), with predominant and increasing resistance to nalidixic acid, chloramphenicol, and streptomycin. This study demonstrated multidrug resistance of the pathogen in pigs likely due to more antimicrobial pressure on big farms, with intriguing resistance to some clinically relevant antimicrobials used in the treatment of yersiniosis in humans.

Prevalence, characterization, and antibiotic susceptibility of Cronobacter spp. in a milk powder processing environment: The first reported case in Serbia.

Cronobacter spp. are opportunistic foodborne pathogens that most often infect neonates and infants through contaminated powdered infant formula. No reports have been published in Serbia on the prevalence of Cronobacter spp. in powdered milk production environments. Consequently, this study aimed to determine the prevalence, molecular characterization, antimicrobial susceptibility, and biofilm-forming ability of Cronobacter spp. isolated from a milk powder plant. Hundred samples were collected from the production facility. Fifteen Cronobacter sakazakii strains were isolated and identified, giving a contamination rate of 15%. Using multi-locus sequence typing, the isolates were divided into five sequence types (STs). Cronobacter sakazakii ST4 (50%), ST1 (16.67%), and ST83 (16.67%) were the dominant STs isolated. A novel sequence type (ST759) was identified and registered in the Cronobacter MLST database. The results of the antibiotic susceptibility testing indicated that C. sakazakii strains were susceptible to piperacillin/tazobactam, ampicillin/sulbactam, and amoxicillin/clavulanate, especially to meropenem and cefotaxime. Most of the ST4 showed moderate-to-strong biofilm-forming ability. The presence of clinically relevant isolates (ST4, ST1, ST83, and ST8) revealed that the production plant is likely a potential concern for public health. Finally, finding new sequence types like the one detected in this study (ST759) underlines evolving genetic changes in C. sakazakii.

Beef abattoir interventions in a risk-based meat safety assurance system.

In risk-based meat safety assurance system, the use of interventions is intended to accomplish the meat safety targets on chilled carcasses, particularly in situations when an abattoir is unable to sufficiently reduce risks arising from specific farms/animal batches by using process hygiene alone. Furthermore, interventions are considered whenever food safety authorities identify meat production processes associated with high risks for consumers. This paper overviews the role of beef interventions in a risk-based, meat safety assurance system. Cattle hide interventions (chemical hide washes and microbial immobilisation treatment with shellac) and beef carcass interventions (pasteurisation treatments with hot water and/or steam and organic (lactic) acid washes), show consistent reduction effects of aerobic bacteria and faecal indicators and reduced prevalences of naturally present VTEC and Salmonella. The review also identified interventions where there was a lack of data and further research was needed, and other contextual factors to inform the risk management decisions for further development of risk-based meat safety assurance system.

Evaluation of public and animal health risks in case of a delayed post-mortem inspection in ungulates.

The potential effects of a 24 or 72-h delay in post-mortem inspection (PMI) of ungulates on public health and monitoring of animal health and welfare was evaluated. The assessment used a survey of meat inspectors, expert opinion, literature search and a stochastic model for Salmonella detection sensitivity. Disease detection sensitivity at a delayed PMI is expected to reduce detection sensitivity to a variable extent, depending on the hazard and on the signs/lesions and organs involved. No reduction is expected for Trichinella detection in meat from susceptible animal species and any decrease in detection of transmissible spongiform encephalopathies (TSEs) will not exceed the current tolerance for fallen stock. A 24-h delay in PMI could result in a small reduction in sensitivity of detection for tuberculosis, echinococcosis and cysticercosis. A greater reduction is expected for the detection of pyaemia and Rift valley fever. For the detection of Salmonella, the median model estimates are a reduction of sensitivity of 66.5% (90% probability interval (PI) 0.08-99.75%) after 24-h delay and 94% (90% PI 0.83-100%) after 72-h delay of PMI. Laboratory testing for tuberculosis following a sampling delay of 24-72 h could result in no, or a moderate, decrease in detection depending on the method of confirmation used (PCR, culture, histopathology). For chemical contaminants, a delay in meat inspection of 24 or 72 h is expected to have no impact on the effectiveness of detection of persistent organic pollutants and metals. However, for certain pharmacologically active substances, there will be a reduced effectiveness to detect some of these substances due to potential degradation in the available matrices (tissues and organs) and the non-availability of specific preferred matrices of choice.

Mapping knowledge and comprehension of antimicrobial stewardship and biosecurity among veterinary students.

OBJECTIVES: As an important public health concern, antimicrobial resistance (AMR) is related to lack of knowledge among healthcare professionals. Since the Global Action Plan on AMR highlights the importance of training all healthcare professionals, it is essential to focus our attention on the education related to judicious antimicrobial use. The current study was the first attempt in southeastern Europe to quantify the knowledge about antimicrobial usage and biosecurity measure among veterinary students. METHODS: This questionnaire-based study was performed between April and May of 2019 on 213 veterinary students of the University of Novi Sad, Serbia and the University of Zagreb, Croatia. RESULTS: Veterinary students appeared to be little aware of antimicrobial use in veterinary medicine contribution to overall AMR since only 56.8% have chosen strong contribution as the answer. Of the students surveyed, only 22.1%/35.7% of them strongly agreed/agreed that the amount of teaching time for pharmacology was about right. Students who denied having good knowledge of the pharmacology of antimicrobials showed higher knowledge about systemic use of antimicrobials in different clinical scenarios (p = 0.002). High importance of some antimicrobials for human medicine was not recognized by surveyed students. Only 8.5% of them identified gentamicin correctly, as first-line therapy. Students expected to graduate later were more likely to identify the importance of rating antimicrobials correctly than those who thought they would graduate earlier (p = 0.002). More than half of students gave correct answer at scenario regarding a dog with recurrent pyoderma by choosing culture and susceptibility (C & S) testing. Our students who think they will graduate sooner have higher knowledge level on C & S testing sample submission for range of clinical scenarios (p = 0.004). Moreover, appropriate use of PPE (personal protective equipment) procedure and biosecurity measure were reported for two thirds of our students in case of only for two clinical scenarios. CONCLUSION: This study reveals that among veterinary students from Croatia and Serbia improved undergraduate education is needed on the AMR with emphasis on antimicrobial stewardship (AMS) and appropriate biosecurity.

The effects of season on health, welfare, and carcass and meat quality of slaughter pigs.

This study assessed the effects of season on health, behaviour, physiological stress parameters, and carcass and meat quality in a total of 480 slaughter pigs. The following health indicators were recorded: pneumonia, pleurisy, milk spots, and pericarditis. Behaviour was monitored during unloading (slipping, falling, turning back, reluctance to move, panting, shivering) and lairaging (panting, shivering, huddling). Blood lactate and glucose concentrations were determined at exsanguination. Performance indices (live weight, daily weight gain), carcass (carcass weight, backfat and loin thickness, lean meat content, carcass lesion score), and meat quality (pH, temperature, drip, thawing and cooking losses, colour, marbling) traits were measured postmortem. Pigs slaughtered in winter had the highest live weight, carcass weight, loin thickness, and carcass lesion score, while the lowest live weight, carcass weight, and backfat thickness were recorded in pigs slaughtered in summer. The highest lactate and glucose concentrations were recorded in pigs slaughtered in summer. The highest prevalence of red, soft, and exudative meat was recorded in pigs slaughtered in winter. Pigs slaughtered in summer had the lowest pH, the highest thawing loss, L* value, b* value, and occurrence of pale, soft, and exudative meat. Pigs slaughtered in autumn had the lowest drip loss, cooking loss, L* value, b* value, and the greatest percentage of red, firm, and nonexudative meat. In conclusion, the summer and winter temperatures compromised health and welfare and reduced carcass and meat quality in slaughter pigs, indicating that protection against heat and cold stress is not yet effective.

Serbian students' knowledge, attitudes and behaviour towards antibiotic use: is there room for improvement?

OBJECTIVES: This study has been aimed at evaluating knowledge, attitudes and behaviour of university students regarding the usage of antibiotics focusing on differences between medical and nonmedical students. METHODS: This cross-sectional questionnaire-based study was performed on 800 students of the University of Novi Sad, Serbia. RESULTS: The identified predictors of adequate antibiotic knowledge were enrolled in medical program, higher grade average and appropriate use of antibiotics during last infection. Multivariate regression identified following predictors of self-medication: being medical student (B = 0.715; p < 0.001), more frequent (B = 0.628; p < 0.001) and irregular (B = 0.584; p = 0.001) antibiotic use, a family member engaged in medical profession (B = 0.789; p < 0.001), living in dormitory (B = 0.679; p = 0.007) or rented apartment (B = 0.621; p = 0.002), using antibiotics until symptoms resolved (B = 1.616; p < 0.001) or until the bottle was finished (B = 0.628; p < 0.001) during the last infection. CONCLUSIONS: Although a high number of students showed adequate knowledge about antibiotics, numerous misconceptions were recorded, including self-medication. Further educational interventions are necessary to improve their understanding, perceptions as well as their behaviour towards antibiotic use.

Heavy metals and PAHs in canned fish supplies on the Serbian market.

The aim of this study was to determine the level of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in 57 samples of canned tuna, 25 samples of canned sardines, and 16 samples of canned smoked sprouts, collected from supermarkets in Serbia. Heavy metal levels (lead, cadmium, mercury, arsenic, iron, copper, and zinc) were determined using an inductive coupled plasma mass spectrometry method. Sixteen analysed PAHs were determined using a gas chromatography-mass spectrometry method. The trace elements in canned fish were in the range (mg kg-1) of 0.01-0.28 for lead, 0.003-0.08 for cadmium, 0.007-0.64 for mercury, 0.17-3.73 for arsenic, 3.88-52.2 for iron, 0.2-5.95 for copper, and 1.35-44.5 for zinc. Total PAH levels reached 17.67 µg kg-1 in canned tuna and 15.12 µg kg-1 in sardines, whereas in smoked sprouts it amounted to 57.19 µg kg-1. Some of the samples contained cadmium, arsenic, copper, and benzo(a)pyrene above the limits as set by the European and Serbian legislation.

Green offal inspection of cattle, small ruminants and pigs in the United Kingdom: Impact assessment of changes in the inspection protocol on likelihood of detection of selected hazards.

The changes in detection of selected public and animal health as well as welfare hazards due to the change in current inspection of green offal in cattle, small ruminants and pigs were assessed. With respect to public health and animal health, the conditional likelihood of detection with the current green offal inspection was found to be low for eleven out of the twenty-four selected hazard-species pairings and very low for the remaining thirteen pairings. This strongly suggests that the contribution of current green offal inspection to risk mitigation is very limited for public and animal health hazards. The removal of green offal inspection would reduce the detection of some selected animal welfare conditions. For all selected public and animal health as well as welfare hazards, the reduced detection could be compensated with other pre-harvest, harvest and/or post-harvest control measures including existing meat inspection tasks.

Microbial pathogen control in the beef chain: recent research advances.

Within a recent EU research project ("ProSafeBeef"), research on foodborne pathogens in the beef chain was conducted by using a longitudinally integrated (fork-to-farm) approach. There is not any "single intervention-single chain point" combination by which the pathogens would be reliably and entirely eliminated from the chain resulting in total prevention of pathogens in beef and products thereof at the consumption time. Rather, a range of control interventions have to be applied at multiple points of the chain, so to achieve an acceptable, ultimate risk reduction. Various novel interventions were developed and evaluated during the project, and are briefly summarized in this paper. They include on-farm measures, risk categorisation of cattle presented for slaughter, hygiene-based measures and antimicrobial treatments applied on hides and/or carcasses during cattle slaughter, those applied during beef processing-storage-distribution, use of Time Temperature Integrator-based indicators of safety, and effective sanitation of surfaces.

A study of haptoglobin levels in groups of cattle and pigs with and without abnormalities at meat inspection.

A total of 96 bovines originating from 36 farms and 97 pigs from five farms were slaughtered in two multispecies abattoirs and subjected to official meat inspection and haptoglobin (Hp) testing using a single radial immunodiffusion method. No direct correlation between Hp level and specific postmortem abnormalities was found at individual cattle/pig level. However, at animal group level, the mean of Hp values (in both cattle and pigs) were statistically significantly higher in animals with abnormalities than in those without. The study indicated that the mean Hp value in groups of cattle or pigs can be useful as an overall objective indicator of the overall status of cattle/pig batches when analyzing the food chain information as a part of the antemortem inspection at abattoirs, but related specific Hp criteria are currently missing. Because of the large variability and nonspecific nature of Hp-related responses in cattle and pigs, establishing a single, reliable cutoff Hp value differentiating batches that may pose public health risks does not appear as a realistic approach presently. Rather, establishing wider, unsatisfactory/marginal/satisfactory ranges of batch-based Hp values indicating general appropriateness of the cattle/pigs source appears more promising. For that, wider Hp baseline studies are necessary at abattoir.