Foods Of Animal Origin Research Articles

Micro(nano)plastic and Related Chemicals: Emerging Contaminants in Environment, Food and Health Impacts

Microplastic pollution is a problem of increasing concern in food, and while food safety issues around the world are serious, an increasing number of food safety issues related to microplastics have become the focus of people’s attention. The presence of microplastics in food is a worldwide problem, and they are present in all kinds of foods, foods of both animal and plant origin, food additives, drinks, plastic food packaging, and agricultural practices. This can cause problems for both humans and the environment. Microplastics have already been detected in human blood, heart, placenta, and breastmilk, but their effects in humans are not well understood. Studies with mammals and human cells or organoids have given perspective about the potential impact of micro(nano)plastics on human health, which affect the lungs, kidneys, heart, neurological system, and DNA. Additionally, as plastics often contain additives or other substances, the potentially harmful effects of exposure to these substances must also be carefully studied before any conclusions can be drawn. The study of microplastics is very complex as there are many factors to account for, such as differences in particle sizes, constituents, shapes, additives, contaminants, concentrations, etc. This review summarizes the more recent research on the presence of microplastic and other plastic-related chemical pollutants in food and their potential impacts on human health.

Knowledge, attitude and practices towards antibiotic usage among farmers rearing yaks, dzomo and hill cattle in the high-altitude regionsof Himachal Pradesh

The present cross-sectional survey aimed to investigate knowledge, attitudes and practices (KAP) of farmers of high altitude regions of Himachal Pradesh towards antibiotics and their usage. The survey was carried out using pre-validated questionnaires among 162 farmers (40 males and 122 females) engaged in animal husbandry practices particularly rearing yaks, dzomo and hill cattle from Lahaul, Spiti and Kinnaur regions of Himachal Pradesh. More than 75% of the respondents were aware of antibiotics, with females (83.6%) having more knowledge in comparison to males (52.5%). Using antibiotics in lactating animals may lead to, occurrence of antibiotics or their residues in milk, question was correctly answered by 110/162 (67.91%) respondents with significant difference with respect to educational levels. It was observed that 78.68% respondents adopted the best practice of not purchasing antibiotics without prescription. Overall, it was found that farmers’ perceptions of the use of antibiotics and their side effects are directly influenced by their education. Majority of the farmers were having significant knowledge regarding antibiotics, their usage and effects on consumers. They also had very positive attitude towards antibiotic usage but the practices were average in context of purchasing of antibiotics without prescription and consumption of milk from animals undergoing treatment. Therefore, education of farmers on food safety and antibiotic misuse becomes imperative for production of good quality animal origin foods.

Fishy Forensics: FT-NIR and Machine Learning based authentication of Mediterranean Anchovies (Engraulis encrasicolus)

Seafood authentication and traceability is a challenging issue owing to its complex supply chain and fishing in international waters. NIR spectroscopy has been successfully used to authenticate food of animal and plant origin. In this study, FT-NIR was used to discriminate between Mediterranean anchovies (Engraulis encrasicolus) fished from Adriatic, Balearic, and Tyrrhenian Sea. The spectra were prepared using the standard normal variate (SNV) and the Savitzky-Golay 1st derivative, 2nd order (SG), as well as both together. The model was built, after outlier removal, with linear-support vector machine (L-SVM), polynomial-SVM (P-SVM), k-nearest neighbor (k-NN) and Random Forest (RF). Spectral preprocessing improved model classification accuracy for all algorithms. The data could not be put into groups by linear algorithms like L-SVM and k-NN because the NIR spectra were not linear and had many columns. Non-linear algorithms, P-SVM and RF when coupled with SG+SNV, successfully produced models with maximum robustness. P-SVM and RF models had 100% accuracy in training set and 95.7% and 95.5% accuracy in testing set, respectively and 95.2 and 95.1 accuracy in cross-validation set.

Brominated flame retardant in animal feeds from Poland

The safety of food of animal origin is closely related to feed quality. Feed pollution by brominated flame retardants (BFRs) leads to the exposure of animals and consumers of food of animal origin to these substances. The study aimed to assess the concentration of ten PBDE (BDE-28, 47, 49, 99, 100, 138, 153, 154, 183, and 209) congeners and eight nBFRs (TBX, PBT, HBB, PBEB, EH-TBB, BTBPE, BEH-TBPH, and DBDPE) in 59 feed and feed materials from six different feed categories (277/2012/EU). The quantification of analytes was based on isotopic dilution and gas chromatography–high-resolution mass spectrometry (GC-HRMS). All 59 feed samples were contaminated with at least one of the analytes. PBDEs and nBFRs were found in 78% and 91% of the samples, respectively. BFR content ranged from 0.18 to 5.87 μg·kg-1 in feed with a 12% moisture content, and the most contaminated category was vegetable oils, followed by fishmeal, feeds for fish, animal fats, and compound feeds for pigs. The least contaminated samples turned out to be compound feeds for chickens. This study confirms the general trend of decreasing PBDE concentrations in fishmeal. In the investigated samples, BDE-47 and BDE-209 contributed the most to the ∑PBDE content. DBDPE, HBB, and PBT contributed the most to the investigated ∑nBFRs. The widespread occurrence of nBFRs in feed seems disturbing because these compounds have replaced PBDEs. Their concentrations in the feed may most likely exceed those of PBDEs in the coming years.

Safety and efficacy of a feed additive consisting of lutein-rich extract of Tagetes erecta L. for turkeys for fattening (EW Nutrition).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of lutein-rich extract of Tagetes erecta L. as sensory additive (functional group: Colourants (ii) substances which, when fed to animals, add colours to food of animal origin) for turkeys for fattening. The additive is already authorised for use in feed for chickens for fattening and minor poultry for fattening and laying hens and minor poultry for laying. The FEEDAP Panel concluded that the use of lutein-rich extract of T. erecta is safe for turkeys for fattening when used up to the maximum proposed use level of 80 mg total carotenoids/kg complete feed. The Panel concluded that the use of lutein-rich extract of T. erecta in feed for turkeys for fattening under the proposed conditions of use would not be of concern for the consumer, considering also its use in other poultry for fattening and for laying hens. Regarding user safety, the lutein-rich extract of T. erecta extract is irritant to skin and eyes and any exposure is considered a risk. The conclusions on user safety reached for the lutein-rich extract of T. erecta would, in principle, apply to preparations made with it. The use of the additive in feed for turkeys for fattening under the proposed conditions of use is safe for the environment. The FEEDAP Panel concluded that the additive has the potential to colour the skin of turkeys for fattening at the proposed conditions of use.

The gut microbiome without any plant food? A case study on the gut microbiome of a healthy carnivore

Objective The carnivore diet is a ketogenic diet based exclusively on the consumption of food of animal origin. While the impact of various diets on the gut microbiome is extensively documented, the effects of a carnivore diet remain unclear. To address this gap, we conducted a pilot study on the gut microbiome of an individual following a carnivore diet and compared it with that of a subgroup of healthy individuals. Methods A stool sample was collected from a healthy 32-year-old male adhering to a carnivore diet and was sequenced using 16S DNA Amplicon Sequencing. The results were then compared to those from three control groups possessing similar anthropometric characteristics and differing in their frequency of meat consumption. Results The gut microbiome of the carnivore was dominated by the phylum Firmicutes and the genera Faecalibacterium, Blautia, unspecific Lachnospiraceae, Bacteroides, and Roseburia—bacteria known for fiber degradation. Furthermore, neither alpha- nor beta-diversity, nor the functional capacity of the gut microbiome, showed differences when compared to the control groups. Additionally, the gut microbiome of the carnivore showed the least similarities with the microbiome of the cohort consuming meat on a daily basis. Conclusions In our study, we showcase the compositional and functional characteristics of the gut microbiome in an individual on a carnivorous diet, finding no differences in comparison to a control cohort. Further research is needed to investigate the short- and long-term impacts of a carnivorous diet on gut health through cross-sectional and longitudinal studies. Significance statement To the best of our knowledge this is the first study to report on the composition of the gut microbiome of a person adhering long-term to the carnivore diet.

Portable detection of Salmonella in food of animal origin via Cas12a-RAA combined with an LFS/PGM dual-signaling readout biosensor.

Ahighly specific and sensitive rapid two-signal assay was developedfor the detection of Salmonella typhimurium in foods of animal origin. TheinvA gene of Salmonella was usedas the biorecognition element and recombinase-assisted amplification (RAA) technology for signal amplification. By utilizing the specific recognition and efficient trans-cleavage activity of CRISPR/Cas12a, point-of-care testing (POCT) for S. typhimurium was achieved via lateral flow strips (LFS) and personal glucometer (PGM) biosensors as dual signal readout systems, with sensitivities of 33CFU/mL and 20CFU/mL, respectively. Users can select the appropriate test system on the basis of specific application requirements: LFSs are ideal for rapid onsite screening, whereas glucometer biosensors offer precise quantitative determination. This approach simplifies the use of large instruments and overcomes site constraints, demonstrating good accuracy and applicability in animal-derived samples, with significant potential for the detection of other pathogens and for use in restricted environments.

Development of a Method for the Determination of Rifaximin and Rifampicin Residues in Foods of Animal Origin.

Rifaximin and rifampicin are good broad-spectrum antimicrobials. The irrational use of antimicrobial drugs in veterinary clinics could threaten public health and food safety. It is necessary to develop a reliable detection method of the residue for enhancing the rational supervision of the use of such drugs, reducing and slowing down the generation of bacterial resistance, and promoting animal food safety and human health. So, this study developed an LC-MS/MS method for the detection of rifaximin and rifampicin residues in animal-origin foods. The residual rifaximin and rifampicin of homogenized test materials were extracted with acetonitrile-dichloromethane solution or acetonitrile in the presence of anhydrous sodium sulfate and vitamin C, purified by dispersible solid phase extraction, determined by LC-MS/MS, and quantified by the internal standard method. The specificity, sensitivity, matrix effect, accuracy, and precision of the method were investigated in the edible tissues of cattle, swine, or chicken. In addition, the stability of the standard stock solution and the standard working solution was also investigated. The method was suitable for the muscle, liver, kidney, fat, milk, and eggs of cattle, swine, or chicken, as well as fish and shrimp. The specificity of the method was good, and the detection of the analytes was not affected by different matrices. Both the LOD and LOQ of the two analytes were 5 μg/kg and 10 μg/kg, respectively. The results of matrix effects in each tissue were in the range of 80-120%; there were no significant matrix effects. The average accuracy of rifaximin and rifampicin in different foodstuffs of animal origin was between 80% and 120%, and the method precision was below 20% (RSD). The proposed method showed good performance for determination, which could be employed for the extraction, purification, and detection of residual rifaximin and rifampicin in edible animal tissues. The pretreatment procedure of tissue samples was simple and feasible. The method was highly specific, stable, reliable, and with high sensitivity, accuracy, and precision, which met the requirements of quantitative detection of veterinary drug residues.

Yogurt as a fermented food for healthy and sustainable daily consumption. Recommendations to the population

Yogurt has been valued very positively for centuries, but the concern for food sustainability and the fact that it is a food of animal origin has raised doubts about the consumption that may be convenient. The objective of this work is to deepen the topic and establish recommendations for the population. From the nutritional point of view, yogurt is a valuable food, for its high content, quality and bioavailability of its nutrients, in a low energy content, its components together with probiotic microorganisms are provided in a matrix that helps achieve greater nutritional and health benefit. Regular consumption of yogurt has been linked to cardiovascular protection, against diabetes, excess weight, cancer, bone health. Thinking about environmental sustainability, yogurt production is not particularly dangerous, as the kg of CO2 eq (greenhouse gases) associated with their production are the lowest obtained compared to other animal foods and even lower than those associated with the production of some plant foods and the supply of nutrients per 1000 kcal, per 100 g, or per euro is one of the highest available. There is the possibility to further improve sustainability with improvements in animal feed, packaging, transport, etc. Considering this evidence, the daily consumption of yogurt / fermented milk should be included in the food guidelines, not only as one more milk option, but specifying a specific consumption such as a ration / day, this pattern can be useful from the nutritional point of view and for the improvement of public health.

Boronate affinity molecularly imprinted electrochemical sensor based on electrospun carbon nanofibres for selective kanamycin detection

The presence of trace kanamycin (KANA) residues in animal-derived foods from its improper use present a critical public health issue, making the urgent need for the development of sensitive and selective KANA detection methods. In this study, we developed molecularly imprinted polymers (MIPs)-based electrochemical sensor for the detection of KANA, incorporating Co, Mo-doped carbon nanofibres (Co, Mo@CNFs) to modify a glassy carbon electrode (GCE). Then, the MIPs layer was synthesized via electropolymerization using KANA as a template molecule and 3-aminophenylboronic acid (3-APBA) as the functional monomer (as MIPs/Co, Mo@CNFs/GCE), facilitating selective recognition through boric acid affinity. The presence of Co, Mo@CNFs enhanced electron transport across the otherwise insulating MIPs layer, thereby improving the sensor’s selective recognition capabilities. Under optimal conditions, the MIPs/Co, Mo@CNFs/GCE sensor demonstrated precise KANA detection within a concentration range of 1 × 10−2 to 1 × 105 nmol·L−1, achieving a detection limit of 2.56 pmol·L−1. Furthermore, the sensor’s applicability was validated in complex matrices, successfully detecting KANA in serum and milk samples with recovery rates ranging from 95.05 % to 116.43 %. These results confirmed that the proposed sensor is highly effective for detecting KANA in both biological and animal-origin food samples.

EXAMINATION OF THE DYNAMICS OF ANALYZES PERFORMED FOR THE PRESENCE OF RADIONUCLEIDE RESIDUES IN FOOD IN THE PERIOD 2019-2023 IN THE REPUBLIC OF NORTH MACEDONIA

The main focus of this research is to determine the extent of analyzes performed for the presence of radionuclides in food, their dynamics, which radionuclides are present in food, and how much their radioactivity was in the period 2019-2023. The research covers the period from January 01, 2019. until December 31, 2023. The data we used to conduct this research were obtained from the Public Health Institute of R. N. Macedonia. The tests were carried out with accredited methods and by the Regulation on the maximum allowed amounts of radionuclides in food, water, air, land, products, and raw materials of animal and plant origin and objects for general use. Relative numbers and trends are used as statistical methods of work. According to the results, in the period 2019-2023, radionuclides were analyzed in 6065 samples (2711 samples from imports, and 3354 samples from domestic production). The largest amount of radioactivity analyzes were performed in the group of mushrooms (51%) and the group of grain and flour (44%). The scope of analyzes performed for the presence of radionuclide residues in food in R.N. Macedonia shows a downward trend. In the analyzed products, no radioactivity above the limit values was detected (except in 2020 when only in 1 product from the mushroom group - dry morel) detected a value for Cs-137 = 662.8 Bq/kg, and the maximum allowed value is 600 Bq/kg ). It can be concluded from the study that food is safe in terms of the presence of radionuclide residues, but work should be done to increase the volume of analyzes performed for the presence of radionuclides in food, as well as to increase the coverage of different groups of products (fruit, vegetables, coffee, tea, etc.) in which such analyzes would be performed.

Chemiluminescence detection of kanamycin by DNA aptamer regulating peroxidase-like activity of Co3O4 nanoparticles.

Kanamycin (KAN) is widely used as a growth hormone analog and an antibacterial agent. However, abuse of this substance has resulted in the accumulation of excessive residue levels in foods of animal origin, which presents a significant risk to human health. A chemiluminescent aptasensor was constructed for the rapid quantitative detection of KAN by combining the properties of Co3O4 nanoparticles (Co3O4 NPs) nanozyme activity and DNA aptamer with high specificity. The DNA aptamer/Co3O4 NPs nanozyme regulated the chemiluminescence signal by exploiting the chemiluminescent properties of luminol oxidation by H2O2. Specific binding of KAN to the aptamer led to the formation of a steric hindrance block in the solution, which inhibited the activity of nanozyme and reduced signal intensity. The degree of signal reduction is related to the concentration of KAN. Under optimal conditions, there was good linearity between KAN concentration and chemiluminescence signal intensity in the range of 0.5-8.0 μΜ, with a detection limit of 0.26 μΜ. The detection system performed well in the presence of competing antibiotics and was virtually unaffected. The method was also suitable for the detection of KAN in milk samples with sample recoveries of 97.8%-99.1%. The chemiluminescence sensor has the advantages of low cost, specificity, and sensitivity, and does not require an external light source or modification of the nucleic acid aptamer which makes it a promising candidate for applications in the field of food detection.

The acquired pco gene cluster in Salmonella enterica mediates resistance to copper.

The pervasive environmental metal contamination has led to selection of heavy-metal resistance genes in bacteria. The pco and sil clusters are located on a mobile genetic element and linked to heavy-metal resistance. These clusters have been found in Salmonella enterica serovars isolated from human clinical cases and foods of animal origin. This may be due to the use of heavy metals, such as copper, in animal feed for their antimicrobial and growth promotion properties. The sil cluster can be found alone or in combination with pco cluster, either in the chromosome or on a plasmid. Previous reports have indicated that sil, but not pco, cluster contributes to copper resistance in S. enterica Typhimurium. However, the role of the pco cluster on the physiology of non-typhoidal S. enterica remains poorly understood. To understand the function of the pco gene cluster, a deletion mutant of pcoABCD genes was constructed using allelic exchange mutagenesis. Deletion of pcoABCD genes inhibited growth of S. enterica in high-copper medium, but only under anaerobic environment. Complementation of the mutant reversed the growth phenotype. The survival of S. enterica in RAW264.7 macrophages was not affected by the loss of pcoABCD genes. This study indicates that the acquired pco cluster is crucial for copper detoxification in S. enterica, but it is not essential for intracellular replication within macrophages.

The Environmental Perception and Vegetarian Motivation of People in Ho Chi Minh City, Vietnam

Abstract Studies have previously shown that there were many vegetarian movements in the world, using many different models to indicate vegetarian food choice behavior. Among the factors affecting the motivation to become a vegetarian, perception and attitude are considered important factors influencing the decision to switch from using foods of animal origin to plant-based ones. There are many measured aspects of perception ranging from health, religion, love of animals, or animal rights. Among these, environmental perception increasingly shows a clear influence on vegetarian motivation, especially for young people. This current study aims to find out whether factors relating to perception including environmental perception, influence people’s motivation to become vegetarian in Ho Chi Minh City. To achieve this goal, the research surveyed 360 people living in Ho Chi Minh City (divided into three groups (students, office workers, and manual workers) using a direct questionnaire. Research results show that among the four independent variables (perception, ability, opportunity, barriers), there are three variables (1) perception; (2) opportunity; and (3) barriers having a significant relationship with the vegetarian motivation of people in Ho Chi Minh City. From the findings, this study points out key highlights in people’s current vegetarian food choices in this area, including environmental perception.

Fabrication of magnetic functionalized layered double hydroxide nanomaterials for detecting trace fluoroquinolones residues in meat integrated with HPLC-MS/MS

Fluoroquinolones (FQs) are widely used to treat various animal diseases. The high residue of veterinary drugs in animal-origin food are new pollutants that seriously threaten human health. In this work, Fe3O4@LDH/ZIF was prepared by the in situ growth of zeolitic imidazolium skeletons (ZIFs) on Fe3O4@Zn/Al-layered double hydroxides (Fe3O4@Zn/Al-LDH), which was used as the adsorbent of FQs for magnetic solid phase extraction (MSPE). The prepared materials were characterized by using FT-IR, XRD, TEM, SEM, VSM, zeta, and nitrogen adsorption-desorption analyses. Under the optimized conditions, the limit of detections (LODs) of proposed methods for FQs is determined as low as 0.1–0.6 μg·kg−1 with good linearity (R2≥0.9972). Furthermore, the MSPE approach has been effectively utilized to extract of FQs from a range of meat varieties including fish, pork, chicken, bullfrog, and beef. The recoveries from the spiked samples ranged from 86.5 % to 107 %, with relative standard deviations (RSD) below 8.8 %. These results demonstrated that the prepared nanoparticles hold unique advantages for trace FQs analysis in foodstuffs. This study provides a magnetic adsorbent for food sample pretreatment, which can rapidly enrich compounds similar in structure to fluoroquinolones.

Assessment of the presence of multidrug-resistant Escherichiacoli, Salmonella and Staphylococcus in chicken meat, eggs and faeces in Mymensingh division of Bangladesh

The emergence of bacteria that is resistant to several drugs of clinical importance poses a threat to successful treatment, a phenomenon known as multidrug resistance that affects diverse classes of antibiotics. The purpose of this study was to evaluate the prevalence of multidrug-resistant Escherichiacoli, Salmonella spp. and Staphylococcusaureus in chicken egg, meat and faeces from four districts of Bangladesh. A total of 120 chicken samples were collected from different poultry farms. Conventional culture and molecular detection methods were used for identification of bacterial isolates from the collected samples followed by antibiotic susceptibility test through the disc diffusion method, finally antibiotic resistant genes were detected by PCR. E. coli, Salmonella spp. and Staphylococcusaureus were detected in meat, egg and faecal samples. Antimicrobial susceptibility results revealed isolates from faeces were 100 % resistant to amoxicillin, while all S.aureus and Salmonella sp. from faeces were resistant to doxycycline, tetracycline and erythromycin. Salmonella spp. isolates from eggs indicated 100 % resistance to erythromycin, amoxycillin, while E.coli were 100 % resistant to erythromycin. E.coli and S.aureus from meat were 100 % resistant to amoxicillin and erythromycin. However, Salmonella spp. from eggs were 100 % susceptible to doxycycline, gentamicin, levofloxacin and tetracycline. The mecA and aac(3)-IV genes were only found in S.aureus and E.coli, respectively. The Sul1,tetB, and aadA1 were highest in Salmonella spp. and S.aureus, while the sul1,tetA and blaSHV were higher in E.coli. Isolates from all samples were multidrug resistant. These findings indicate a high risk of transmission of resistance genes from microbial contamination to food of animal origin. The study emphasizes the need for effective biosecurity measures, responsible antibiotic use, and strict regulations in poultry production to prevent the spread of antibiotic resistance.

Novel phenazine-based microporous organic network for selective and sensitive determination of trace sulfonamides in milk samples

BackgroundSulfonamide (SA) residues in food of animal origin possess a potential threat to human health and environment. However, due to the polar and ionic characteristics and trace level of SAs and the complexity of food matrices, direct measurement of SAs in these samples is still very difficult. Development of efficient sample pretreatment method for sensitive and selective extraction of trace SAs is of great significance and urgently desired. Therefore, rational design and synthesizing advanced and selective extractants is quite important. ResultsIn this work, a novel phenazine-based microporous organic network (MON) named TEPM-DP is reasonably synthesized and employed as a packing material for selective solid phase extraction (SPE) and sensitive determination of four typical SAs in milk samples. Phenazine-based monomer with aromatic and heteroaromatic ring and numerous N atoms is chosen to construct TEPM-DP adsorbent to provide π-π, hydrogen bonding, hydrophobic, and electrostatic extraction sites for SAs. The proposed method owns wide linear ranges, low limits of detection, high enrichment factors, and good precisions and recoveries for SAs in complex milk samples. The recoveries of SAs on TEPM-DP are much higher than those of commercial C18 and activated carbon. The extraction mechanisms are also elucidated via FT-IR, XPS, and comparative experiments. SignificanceThis work reports the first example of design and synthesizing phenazine-based MON in SPE via a simple and rapid solvothermal method. The results reveal the great prospects of TEPM-DP for enriching polar and ionic SAs in complex samples and uncover the potency of phenazine-based MON in sample pretreatment, which will promote the development of MON.

Optimisation and validation of liquid-liquid extraction of aminoglycosides from foods of animal origin

ABSTRACT This study focused on evaluating and optimising the liquid-liquid extraction (LLE) method for the multi-residue analysis of seven AGs in bovine liver, meat, milk, and kidney in conjunction with liquid chromatography coupled to a quadrupole-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap HRMS) for quantification. Of all the hydrophilic interaction liquid chromatography (HILIC) stationary phases tested, the ZIC-HILIC column yielded the best performance. The method was validated according to Commission Implementing Regulation (CIR) EU 2021/808, which encompassed various concentration ranges from 25–7500 µg/kg. The mean recoveries ranged from 79% for liver matrix to 87% for meat matrix, with coefficients of variation (CV) below 18%. The method exhibited excellent linearity, as indicated by correlation coefficients (R2) greater than 0.9903 across all tested matrices. The decision limit (CCα) and detection capability (CCβ) varied from 62 to 5984 µg/kg and 71 to 6471 µg/kg, respectively. The limits of detection (LOD) and quantification (LOQ) were established between 1 and 45 µg/kg, and 2 and 75 µg/kg, respectively. No AG residues were detected in the 120 samples that were collected from different local markets in Egypt using the developed analytical method.

Biochemical characteristics of E. coli isolated from food of animal origin

Food of animal origin is a potential source of pathogenic E. coli that are dangerous to humans. While most strains are intestinal commensals, some can cause intestinal and extraintestinal infections. Their pathogenicity is associated with the presence of virulence genes, phylo-group and, in some strains, biochemical characteristics. In this study, a total of 61 E. coli isolates from meat, minced meat, meat preparations and carcass swabs from different animal species were analysed. The biochemical properties of the strains were determined using VITEK2 system and the data was compared with the presence of virulence genes from previous studies. The results showed a correlation between the presence of the eae virulence gene and the alkalinization of succinate. In addition, the presence of the virulence gene cnf1 was correlated with the enzyme tyrosine arylamidase, though the correlation between biochemical characteristics and the presence of virulence genes is questionable due to the small sample size and more strains need to be tested for further conclusions. Although no significant correlations were found between biochemical characteristics and the presence of virulence genes, this study describes the diversity of E. coli in the Republic of Croatia. The collected data also reveal new insights into biochemical characteristics of E. coli isolated from domestic and wild animals in the Republic of Croatia.

Control of residues of non-authorized pharmacologically active substance in food of animal origin. Results of a proficiency test for determination of chloramphenicol in honey organized by the Italian National Reference Laboratory for Residues

Chloramphenicol is a non-authorized substance for veterinary treatments. The Commission Regulation (EU) 2019/1871 set a Reference Point of Action (RPA) equal to 0.15 µg/kg in force from 28 November 2022, lowering the Minimum Required Performance Limit set in the Commission Decision 2002/657/CE. A Proficiency testing (PT) for the determination of chloramphenicol in honey was organized by the Italian National Reference Laboratory (NRL) for Residues to check the capability of official laboratories (OfLs) to enforce the new RPA. Six Italian OfLs and five European laboratories joined PT and received a blank and two spiked samples. The reference values (0.17 µg/kg and 0.34 µg/kg) were established as consensus from expert laboratories (the European Union Reference Laboratory and some NRLs). The PT was organized before the enforcement of the new RPA giving the OfLs the chance to test their methods in an early stage. Six participants sent results using both screening and confirmatory methods, two submitted only confirmatory data and three performed exclusively screening analysis. For screening methods all laboratories discriminated between blank and contaminated samples. The z scores were calculated only for confirmatory data and all laboratories got a |z|< 2 corresponding to a satisfactory performance.