Quick and high-throughput quantification of ß-agonist residues in bovine liver, meat, milk, kidney, poultry, and egg using dispersive solid phase extraction.

A reliable liquid chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap HRMS) method was developed for the simultaneous identification and quantification of 13 ß-agonist residues in bovine liver, meat, milk, kidney, poultry, and egg. Dispersive-solid phase extraction (d-SPE) using acetonitrile (ACN) was used to prepare the samples. The analyte in the extracts was separated on a reversed-phase Accucore aQ (50 mm × 2.1 mm, 2.6 µm) using a mobile phase of an aqueous solution containing 2 mM ammonium acetate and acetonitrile (ACN) 0.1 % formic acid. The method was validated in accordance with Commission Implementing Regulation (CIR) EU 2021/808 at six different concentrations ranging from 0.1 to 5 µg/kg. The mean recoveries ranged from 65 to 94 %, while repeatability and reproducibility values were all below 13 %. The linearity, as correlation coefficients (R2) ranged from 0.9955 to 0.9999. The decision limit (CCα) and detection capability (CCß) ranges were 0.11-0.13 µg/kg and 0.12-0.15 µg/kg, respectively. The limits of detection (LOD) and limits of quantification (LOQ) were in the range of 0.004-0.048 µg/kg and 0.010-0.075 µg/kg, respectively. Of the 180 samples that were collected from local markets in Egypt, 21.11 % had ß-agonist residues. The mean concentration (µg/kg) and detection frequency (%) of the most frequently found ß-agonist in the samples were as follows: terbutaline (2.63 µg/kg and 90 %), ractopamine (5.14 µg/kg and 23.3 %). The method's applicability was verified by successfully completing two rounds of proficiency testing (PT).

A Novel Method for the Determination of Squalene, Cholesterol and Their Oxidation Products in Food of Animal Origin by GC-TOF/MS.

Cholesterol present in food of animal origin is a precursor of oxysterols (COPs), whose high intake through diet can be associated with health implications. Evaluation of the content of these contaminants in food is associated with many analytical problems. This work presents a GC-TOF/MS method for the simultaneous determination of squalene, cholesterol and seven COPs (7-ketocholesterol, 7α-hydroxycholesterol, 7ß-hydroxycholesterol, 25-hydroxycholesterol, 5,6α-epoxycholesterol, 5,6ß-epoxycholesterol, cholestanetriol). The sample preparation procedure includes such steps as saponification, extraction and silylation. The method is characterized by high sensitivity (limit of quantification, 0.02-0.25 ng mL-1 for instrument, 30-375 µg kg of sample), repeatability (RSD 2.3-6.2%) and a wide linearity range for each tested compound. The method has been tested on eight different animal-origin products. The COP to cholesterol content ratio in most products is about 1%, but the profile of cholesterol derivatives differs widely (α = 0.01). In all the samples, 7-ketocholesterol is the dominant oxysterol, accounting for 31-67% of the total COPs level. The levels of the other COPs range between 0% and 21%. In none of the examined products are cholestanetriol and 25-hydroxycholesterol present. The amount of squalene, which potentially may inhibit the formation of COPs in food, ranges from 2 to 57 mg kg-1.

Hygiene practices of food of animal origin operators in primary schools in the Mono Department of Benin. A cross-sectional study.

Food of animal origin is an important source of proteins for human beings. However, they are subject to microbial contamination. It is essential to ensure the safety of food products intended for school children regarding their vulnerability to food poisoning. Good sanitary quality of these products requires the respect of good practices during their processing and distribution. This study aims to evaluate the conditions of processing and sale of food of animal origin to school children in public schools, with or without canteens, in the Department of Mono in southern Benin. In the Department of Mono in the Republic of Benin, 137 operators were interviewed in public schools, with one operator per school, using a questionnaire created on the Epicollect5 platform. The interview showed that the operators involved in the processing and sale of food to school children were women. Most of these operators had primary education and did not undergo a medical examination. They transported food of animal origin mixed with other types of food. Frying and cooking were used to prepare or process the food. Direct observation revealed that food is produced in an unhealthy environment. The operators did not wear gloves during food processing but some wore aprons. All the operators washed their hands with soap and water (tap or well water) after using the toilet. There was not an adequate handwashing facility. The majority of operators used wooden cutting boards. Overall, food operators especially in schools without a canteen do not follow good hygiene and manufacturing practices in the kitchen. To guarantee food safety for school children, training should be organized to make operators aware of good hygiene and manufacturing practices in kitchens.

Nontyphoid Salmonella in farm animals and food products in the Middle East and North Africa: a systematic review.

Aim: This study aimed to document the prevalence, serotype distribution and antibiotic resistance of nontyphoidal Salmonella in animal food products from Middle East/North Africa (MENA) countries. Methods: Peer-reviewed articles published from 1 January 2011 to 7 March 2023 were included and the data were narratively synthesized and statistically analyzed to estimate and compare the overall prevalence. Results: The authors found a high prevalence of Salmonella in MENA countries (12.80%), with the highest prevalence in Lebanon (41.10%). Poultry had a higher prevalence of Salmonella (14.49%) than livestock (9.62%). Salmonella enteritidis was the most commonly identified serotype (21.99%), and sulfamethoxazole had the highest resistance rate (78.81%). Conclusion: The authors emphasize the importance of implementing control measures in MENA countries to limit the spread of the Salmonella pathogen.

Critical Evaluation of Two Qualitative Analytical Approaches for Multiclass Determination of Veterinary Drugs in Bovine Muscle Using UHPLC-Q-Orbitrap: The Wind of Change in Brazilian Monitoring.

Food safety is recognized as a main requirement for consumers, food industries, and official laboratories. Here, we present the optimization and screening qualitative validation of two multianalyte methods in bovine muscle tissues by ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry with an Orbitrap-type analyzer, operated with a heated ionization source in positive and negative mode. This aims for not only the simultaneous detection of veterinary drugs regulated in Brazil but also the prospection of antimicrobials not yet monitored. Two different sample preparation procedures were applied: method A-generic solid-liquid extraction with 0.1% formic acid (v/v) in an aqueous solution of EDTA 0.1% (w/v)-acetonitrile-methanol (1:1:1, v/v/v), followed by an additional ultrasound-assisted extraction and method B-QuEChERS. In both procedures, selectivity showed satisfactory conformity. From a detection capability (CCß) equivalent to ½ the maximum residue limit, >34% of the analyte resulted in a false positive rate of <5%, preponderant by the QuEChERS method, which exhibited a higher yield of the sample. The results showed the potential application of both procedures in the routine analysis of foods by official laboratories, enabling the expansion of this methodological portfolio as well as its analytical scopes, thus optimizing the control of residues of veterinary drugs in the country.

Antibiotic Resistance in Campylobacter: A Systematic Review of South American Isolates.

In recent years, Campylobacter has become increasingly resistant to antibiotics, especially those first-choice drugs used to treat campylobacteriosis. Studies in South America have reported cases of antibiotic-resistant Campylobacter in several countries, mainly in Brazil. To understand the current frequency of antibiotic-resistant Campylobacter in humans, farm animals, and food of animal origin in South America, we systematically searched for different studies that have reported Campylobacter resistance. The most commonly reported species were C. jejuni and C. coli. Resistance to ciprofloxacin was found to be ubiquitous in the isolates. Nalidixic acid and tetracycline showed a significantly expressed resistance. Erythromycin, the antibiotic of first choice for the treatment of campylobacteriosis, showed a low rate of resistance in isolates but was detected in almost all countries. The main sources of antibiotic-resistant Campylobacter isolates were food of animal origin and farm animals. The results demonstrate that resistant Campylobacter isolates are disseminated from multiple sources linked to animal production in South America. The level of resistance that was identified may compromise the treatment of campylobacteriosis in human and animal populations. In this way, we are here showing all South American communities the need for the constant surveillance of Campylobacter resistance and the need for the strategic use of antibiotics in animal production. These actions are likely to decrease future difficulties in the treatment of human campylobacteriosis.

Fast and Sensitive Analysis of Short- and Long-Chain Perfluoroalkyl Substances in Foods of Animal Origin.

The availability of sensitive analytical methods to detect per- and polyfluoroalkyl substances (PFASs) in food of animal origin is fundamental for monitoring programs to collect data useful for improving risk assessment strategies. The present study aimed to develop and validate a fast and sensitive method for determining short and long-chain PFASs in meat (bovine, fish, and swine muscle), bovine liver, hen eggs, and cow's milk to be easily applicable in routine analysis of food. A QuEChERS extraction and clean-up method in combination with liquid chromatography coupled to mass spectrometry (LC-MSMS) were used. The method resulted in good linearity (Pearson's R > 0.99), low limits of detection (7.78−16.35 ng/kg, 8.26−34.01 ng/kg, 6.70−33.65 ng/kg, and 5.92−19.07 ng/kg for milk, liver, egg, and muscle, respectively), and appropriate limits of quantification (50 ng/kg for all compounds except for GenX and C6O4, where the limits of quantification were 100 ng/kg). Trueness and precision for all the tested levels met the acceptability criteria of 80−120% and ≤20%, respectively, regardless of the analyzed matrix. As to measurement uncertainty, it was <50% for all compound/matrix combinations. These results demonstrate the selectivity and sensitivity of the method for simultaneous trace detection and quantification of 14 PFASs in foods of animal origin, verified through the analysis of 63 food samples.

The Current Status of Analytical Methods Applied to the Determination of Polar Pesticides in Food of Animal Origin: A Brief Review.

The use of high polar pesticides such as glyphosate and metabolites has increased due to their low cost, low persistence in the environment and high effectiveness. The use of glyphosate is currently permitted in the European Union until 15 December 2022. However, the possible toxic effects on human health and the environment are under debate. Their widespread application on various crops might lead to residues in food intended for animal consumption. For this reason, the Commission, implementing Regulation (EU) 2021/601, recommends the analyses of polar pesticides, not only in matrices of plant origin, but also in those of animal origin such as fat, liver, milk and eggs throughout the years 2022, 2023 and 2024. The determination of polar pesticides is hampered by their chemical nature, which poses challenges both in the instrumental detection (poor column retention, low molecular weight MS/MS fragments, etc.) and in the management of matrix effects, which may vary significantly from matrix to matrix within the same food commodity group. For these reasons, nowadays, there is a limited number of methods for the detection of polar pesticides in food of animal origin. This brief review discusses the different approaches for the simultaneous determination of polar pesticides in food of animal origin using both chromatographic and non-chromatographic techniques.

Development of multidrug-resistant Escherichia coli in some Egyptian veterinary farms.

Background and Aim: Food of animal origin is considered a major source of foodborne diseases. In this context, multidrug-resistant (MDR) Escherichia coli pose a serious hazard to public health due to the consumption of food contaminated with antibiotics that are used for the treatment of various bacterial infections in farm animals. Therefore, this study aimed to determine the effect of the excessive use of antibiotics on the development of MDR E. coli strains in Egyptian poultry, dairy, and meat farms. Materials and Methods: A total of 1225 samples were randomly collected from poultry, dairy, and meat products intended for human consumption in different governorates. E. coli were isolated from the collected samples and subjected to biochemical identification and antibiotic sensitivity tests with antibiotics commonly used in human and veterinary medicine. Then, amoxicillin (AML)- and oxytetracycline (OT)-resistant E. coli isolates were subjected to a polymerase chain reaction test to detect the bla TEM and tetA genes, respectively. Results: E. coli were isolated from 132 out of 350, 148 out of 350, 177 out of 350, and 35 out of 175 poultry, milk, meat, and human samples, respectively. Most of the isolates expressed multidrug resistance, and resistance genes (bla TEM and tetA) were detected in all the tested AML- and OT-resistant E. coli isolates. Conclusion: Foods of animal origin may represent a source of MDR E. coli, which can be a major threat to public health.

Development and Validation of Multi-Residue Method for Drugs Analysis in Human Feces by Liquid Chromatography-Tandem Mass Spectrometry.

The use of veterinary drugs in animal production is a common practice to secure animal and human health. However, residues of administrated drugs could be present in animal food products. Levels of drugs in food of animal origin are regulated within the European Union. In recent years, residues have been detected not only in food, but also in the environmental elements such as water or soil, meaning that humans are involuntarily exposed to these substances. This article presents a multiclass method for the analysis of various therapeutic groups of pharmaceuticals in human feces. Pharmaceuticals are extracted from feces with an acid extraction solvent, and after filtration the extract was analyzed by HPLC-MS/MS. A limit of detection of 10 ng/g was achieved for 9 pharmaceuticals, with linearity over 0.99 and repeatability and reproducibility lower than 20%. The method was satisfactorily applied in 25 feces samples of individuals that had declared not to be under medical treatment for the last two months. Results indicate the presence of six different compounds at concentration between 10 and 456 ng/g. This preliminary study showed the involuntary exposure of human gut microbiota to active substances such as pharmaceuticals.

The ability of Aliarcobacter butzleri strains isolated from foods of animal origin in Costa Rica to form biofilm.

Aliarcobacter butzleri is a zoonotic emerging food and waterborne pathogen widely distributed in nature. It is present in food processing environments and can easily be spread through the food industry because of its ability to form biofilm. The aim of this work was to determine the ability of strains isolated in Costa Rica from different food matrixes of animal origin to form biofilm. Thirty-eight A. butzleri strains previously isolated and identified from animal origin products were analyzed using the method described by Stepmovic et al. (2000), in three culture broths, brain heart infusion broth, Boer broth and Houf broth. Results showed that 67% of poultry origin strains, 62.5% of meat origin strains and just 8% of milk origin strains showed ability to form biofilm. The findings of this study confirm the adherence ability of A. butzleri to form biofilm, a characteristic that can promote dispersion and cross contamination along food industry processing lines.

Global Prevalence of Vancomycin-Resistant Enterococci in Food of Animal Origin: A Meta-Analysis.

Vancomycin-resistant enterococci (VRE) are a leading cause of nosocomial infections in patients worldwide. VRE contamination in food of animal origin may create a risk for human health. This study was conducted to estimate the pooled prevalence of VRE in food of animal origin worldwide, to assess the result heterogeneity, and to determine cumulative evidence and the trend of the prevalence over time. Relevant studies were retrieved from PubMed, Scopus, and Web of Science. A random-effects model was used to calculate the pooled prevalence of VRE in food of animal origin. Subgroup meta-analysis was used to assess the heterogeneity of the results. A cumulative meta-analysis and meta-regression were conducted to determine cumulative evidence and the trend of the prevalence of VRE in food of animal origin over time, respectively. Of the 1352 retrieved studies, 50 articles were included. The pooled prevalence of VRE in food of animal origin was 11.7% (95% confidence interval [95% CI] = 8.4 to 16.0). Subgroup meta-analyses showed a significant difference in the prevalence of VRE for two characteristics. First, for the source of food, the prevalence of VRE was highest in aquatic food (43.4% [95% CI = 28.4 to 59.7]) and lowest in dairy food (4.1% [95% CI = 1.7 to 9.8]). Second, for continents, the prevalence of VRE was highest in Africa (18.5% [95% CI = 12.8 to 26.1]) and lowest in North America (0.3% [95% CI = 0.1 to 1.1]). Cumulative evidence showed two distinct features in two different periods. The pooled prevalence of VRE rapidly decreased from 79.3% in 1998 to 13.1% in 2003; it has slightly fluctuated between 10.5% and 20.5% since 2004. The results of the meta-regression indicated that the prevalence gradually decreased over time. In conclusion, the estimate of overall VRE prevalence worldwide in food of animal origin was ∼12%, indicating the burden of VRE contamination in food of animal origin.

Rapid extraction of total lipids and lipophilic POPs from all EU-regulated foods of animal origin: Smedes' method revisited and enhanced.

BACKGROUND: Persistent organic pollutants (POPs) such as dioxins, dioxin-like chemicals and non-dioxin-like PCBs causing adverse effects to human health bio-accumulate through the food web due to their affinity for adipose tissues. Foods of animal origin are therefore the main contributors to human dietary exposure. The European Union's (EU) food safety policy requires checking of a wide range of samples for compliance with legal limits on a regular basis. Several methods of varying efficiency are applied by official control laboratories for extraction of the different classes of lipids and associated POPs, bound to animal tissue and animal products in varying degrees, sometimes leading to discrepancies especially in fresh weight based analytical results. RESULTS: Starting from Smedes' lipid extraction from marine tissue, we optimized the extraction efficiency for both lipids and lipophilic pollutants, abandoning the time-consuming centrifugation step. The resulting modified Smedes extraction (MSE) method was validated based on multiple analyses of a large number of real world samples, matrix calibration and performance assessment in proficiency testing utilizing both instrumental and bioanalytical methodologies. Intermediate precision in 12 different foods was below 3% in chicken eggs, egg powder, animal fat, fish, fish oil, poultry, whole milk, milk fat and milk powder, and below 5% in bovine meat, liver, and infant food. In comparison to Twisselmann hot extraction, results presented here show an increased efficiency of MSE by +25% for bovine liver, +14% for chicken eggs, +13% for poultry meat, +12% for fish, 8% for bovine meat, and 6% for infant food. CONCLUSIONS: For the first time, a fast and reliable routine method is available that enables the analyst to reproducibly extract "total" lipids from any EU-regulated food sample of animal origin within 6 to 8 minutes. Increased efficiency translates into a considerable increase in both lipid and wet weight-based analytical results measured for associated POPs, reducing the risk of false non-compliant results. Compared to a 4 hour Twisselmann extraction, the extraction of 1000 samples using MSE would result in annual savings of about 250 hours or 32 working days. Our MSE procedure contributes to the European Commission's objective of harmonising analytical results across the EU generated according to Commission Regulation (EU) 2017/644.

Avaliação de indicadores higienicossanitários em mortadelas fatiadas / Evaluation of sanitary hygienic indicators in the sliced bolognas

Os embutidos cárneos estão entre os produtos mais consumidos e comercializados e podem representar uma importante fonte de contaminação por micro-organismos patogênicos ou deteriorantes decorrentes de manipulação excessiva, do aumento da superfície de contato e pela maior exposição ao oxigênio atmosférico. Este trabalho avaliou a qualidade microbiológica de mortadelas fatiadas comercializadas em Fortaleza, CE. Foram coletadas 12 amostras de mortadelas, de diferentes marcas, em supermercados de Fortaleza, CE e estas foram fatiadas e embaladas no momento da compra. As amostras foram submetidas à avaliação microbiológica quanto à presença de coliformes termotolerantes, estafilococos coagulase positiva e presença/ausência de Salmonella spp. Os resultados obtidos demonstraram que todas as amostras analisadas estavam dentro dos padrões estabelecidos pela legislação brasileira. A presença de coliformes e estafilococos coagulase positiva nos alimentos, mesmo que seja em níveis inferiores aos preconizados pela legislação vigente, pode indicar condições higienicossanitárias insatisfatórias. Neste contexto, enfatiza-se a necessidade de efetuar a adoção de boas práticas em supermercados e maior fiscalização por parte dos órgãos responsáveis, com o intuito de minimizar os possíveis problemas de saúde pública.

Meat sausages are among the mostly consumed and commercialized products, and they are the important source of contamination by pathogenic or deteriorating microorganisms due to the excessive manipulation, the increased surface contact and the considerable exposure to the atmospheric contents. The objective of this study was to evaluate the microbiological quality of sliced mortadella commercialized in Fortaleza, CE. Twelve samples of mortadella from different brands were collected in supermarkets located in Fortaleza, CE, and they were sliced and packed at the time of purchase. The samples were evaluated by the microbiological analyses for detecting the occurrence of thermotolerant coliforms, coagulase positive staphylococci and presence/absence of Salmonella spp. The results from the present study showed that all of the analyzed samples were within the standards established by the Brazilian legislation. The occurrence of coliforms and coagulase-positive staphylococci in food, even at lower levels than those recommended by current legislation, they indicate the unsatisfactory sanitary hygienic conditions. Therefore, it is emphasized the need to adopt the good practices in supermarkets and a major supervision by the responsible agencies, in order to minimize the occurrence of possible public health problems.

Multi-analyte method for the analysis of legacy and alternative brominated and chlorinated flame retardants in food products of animal origin using gas chromatography - magnetic sector high resolution mass spectrometry.

An analytical method was developed and validated for the analysis of 32 halogenated flame retardants (HFRs), including 13 polybrominated diphenyl ethers (PBDEs), 9 dechlorane-related compounds (DRCs) and 10 of the so-called alternative BFRs in food samples of animal origin. Gas chromatography (GC) coupled with magnetic sector high resolution mass spectrometry (HRMS) was used for the instrumental analysis. Intralaboratory validation of the developed method was performed in terms of recovery, repeatability, linear calibration ranges, instrumental and method limits of quantitation (i-LOQ and m-LOQ). Where possible, trueness was verified by the analysis of reference materials (RMs). For analytes with available isotopically labeled surrogates, recoveries in the range of 70-120% and repeatability rates below 20% were observed, while for compounds quantitated using absolute calibration the values of recovery ranged from 59 to 153% and the repeatability in terms of RSDs was in the range of 1-26%. The values measured for the four analyzed RMs agreed with the provided consensus values, revealing that the recovery of reference concentrations for compounds with assigned consensus values was in 72-119% range. The elaborated method met the sensitivity criteria according to the Commission Recommendation, 2014/118/EU on the monitoring of BFRs in food products. The developed method was successfully applied for the analysis of numerous food samples. The analyses revealed ubiquitous presence of PBDEs and the majority of DRCs in the analyzed samples, while alternative BFRs were detected only occasionally.

Impact of Selenium Addition to Animal Feeds on Human Selenium Status in Serbia.

Research conducted during the 1980s demonstrated Se deficiency in humans. Increased inclusion of selenium in animal feeds started from the year 2000 onwards. The aim of this study was to estimate the effects of selenium inclusion in animal feeds on human selenium status and dietary habits of the Serbian population related to food of animal origin. Plasma selenium concentration in healthy adult volunteers, including residents of one of the regions with the lowest (Eastern Serbia, n = 60) and of one of the regions with the highest Se serum levels reported in the past (Belgrade, n = 82), was determined by hydride generation atomic absorption spectrometry. Multivariate analysis was employed to determine the correlation between Se plasma levels and dietary intake data derived from food frequency questionnaires and laboratory tests. The mean plasma Se level of the participants was 84.3 ± 15.9 µg/L (range: 47.3-132.1 µg/L), while 46% of participants had plasma Se levels lower than 80 µg/L. Frequency of meat, egg, and fish consumption was significantly correlated with plasma selenium level (r = 0.437, p = 0.000). Selenium addition to animal feed in the quantity of 0.14 mg/kg contributed to the improvement of human plasma selenium levels by approximately 30 µg/L.

Polymerase chain reaction detection of genes responsible for multiple antibiotic resistance Staphylococcus aureus isolated from food of animal origin in Egypt.

AIM: The aim of our study was polymerase chain reaction (PCR) detection of the genes responsible for the multiple antibiotic resistance S. aureus isolated from food of animal origin in Egypt. MATERIALS AND METHODS: A total of 125 samples were randomly collected from milk, meat, and their products from Giza and Beni-Suef Governorates markets. The S. aureus isolates were subjected to antimicrobial sensitivity tests using four antibacterial disks (Oxoid), and then the polymerase chain reaction (PCR) was performed for detection of antibiotic resistance genes. RESULTS: Out of 125 samples, 19 S. aureus isolates were detected. All detected isolates were multiple drug resistance (MDR). The penicillin-, erythromycin-, kanamycin-, and tetracycline-resistant isolates were examined by PCR for resistance genes blaZ, (msrA, ermB, and ermC), aac(6')aph (2"), and tetK. The isolates harbored these resistance genes with percentage of 100% (100%, 0%, and 100%), 62.5%, and 100%, respectively. CONCLUSION: Contaminated foods of animal origin may represent a source of MDR S. aureus that can be a major threat to public health.

Analysis of cannabinoids by liquid chromatography-mass spectrometry in milk, liver and hemp seed to ensure food safety.

A method for determining cannabinoids, Δ9-tetrahidrocannabinol (THC), 11-nor-9-carboxy-Δ9-THC (THC-COOH) and 11-hidroxy-Δ9-THC (THC-OH) in milk, liver and hemp seeds based on liquid chromatography tandem mass spectrometry has been optimized and validated. Analytes were extracted with methanol and the extracts cleaned-up by solid-phase extraction using Oasis HLB (60mg). The developed method was validated according to the Commission Decision 2002/657/EC. The decision limit (CCα) and detection capability (CCß) ranged from 3.10-10.5ngg-1 and 3.52-11.5ngg-1, the recoveries were 76-118% and matrix effect ranged from -17.8% to 19.9% in the three matrices studied. The method was applied to food samples obtaining positive results for THC in hemp seeds (average 0.82µgg-1) and three brands of junior formula milk at concentrations from 4.76 to 56.11ngg-1. The developed method was suitable achieving identification and quantification of cannabinoids in food matrices.

Antimicrobial Resistance and Molecular Characterization of Extended-Spectrum ß-Lactamases and Other Escherichia coli Isolated from Food of Animal Origin and Human Intestinal Isolates.

Antibiotics have always appeared miraculous, saving innumerable lives. However, the unwise use of antimicrobial drugs has led to the appearance of resistant bacteria. The purpose of this study was to evaluate antimicrobial resistance in Escherichia coli (n =160) isolated from food of animal origin. The focus was on E. coli -producing extended-spectrum ß-lactamases. E. coli was chosen because it is a part of the normal microbiota in mammals and can enter the food chain during slaughtering and food manipulation. Subsequently, its resistance genes can be transferred to pathogenic bacteria and human microbiota. Phenotypic and genotypic analyses of selected antimicrobial resistances were carried out together with a molecular analysis of virulence genes. E. coli isolates from food of animal origin were compared with clinical E. coli strains isolated from the human intestinal tract. Extended-spectrum ß-lactamase-producing E. coli isolates were found in 9.4% of food isolates and in 1.8% of intestinal isolates. Phylogenetically, the majority of food (86.3%) and intestinal E. coli (58.1%) isolates were found to belong to the commensal phylogenetic groups A and B1. The distribution of 4 of 14 analyzed virulence factors was similar in the food and intestinal isolates. Strains isolated from food in Slovenia harbored resistance genes and virulence factors, which can constitute a problem for food safety if not handled properly.

Analytical Strategy for Determination of Chloramphenicol in Different Biological Matrices by Liquid Chromatography - Mass Spectrometry.

INTRODUCTION: The main problem in determination of chloramphenicol in food of animal origin is a large number of matrices. The main target of this study was to create a method for determination and confirmation of chloramphenicol in products and food of animal origin. MATERIAL AND METHODS: Each 5 g matrix sample was mixed with 5 mL of water and 10 mL of acetonitrile/ethyl acetate, homogenised, and centrifuged. The organic layer was evaporated and redissolved in 6 mL of 4% NaCl. The extract was cleaned up by SPE technique. Chloramphenicol was analysed by LC-MS/MS in electrospray mode. RESULTS: The procedure was validated according to the Commission Decision No. 2002/657/EC. The apparent recoveries were in the range of 92.1% to 107.1% with a repeatability less than 11.0% (4.4%-11.0%) and within-laboratory reproducibility below 13.6% (4.7%-13.6%). CONCLUSION: The method was successfully validated and proved to be efficient, precise, and useful for quantification of chloramphenicol in more than 20 different matrices.