Fresh Chicken Samples Research Articles

CRISPR-Cas12a-Mediated Hue-Recognition Lateral Flow Assay for Point-of-Need Detection of Salmonella.

Nucleic acid detection of pathogens in a point-of-need (PON) manner is of great significance yet remains challenging for sensitive and accurate visual discrimination. Here, we report a CRISPR-Cas12a-mediated lateral flow assay for PON detection of Salmonella typhimurium (S.ty) that is a prevailing pathogen disseminated through tainted food. The variation of the fluorescence color of the test line is exploited to interpret the results, enabling the discrimination between positive and negative samples on the basis of a hue-recognition mechanism. By leveraging the cleavage activity of Cas12a and hue-recognition readout, the assay facilitated by recombinase polymerase amplification can yield a visual detection limit of 1 copy μL-1 for S.ty genomic DNA within 1 h. The assay also displays a high specificity toward S.ty in fresh chicken samples, as well as a sensitivity 10-fold better than that of the commercial test strip. Moreover, a semiquantitative detection of S.ty ranging from 0 to 4 × 103 CFU/mL by the naked eye is made possible, thanks to the easily discernible color change of the test line. This approach provides an easy, rapid, accurate, and user-friendly solution for the PON detection of Salmonella and other pathogens.

Identification of metabolite biomarkers in Salmonella enteritidis-contaminated chickens using UHPLC-QTRAP-MS-based targeted metabolomics

This study aimed to characterize the metabolic profile of Salmonella enteritidis (S. enteritidis) in chicken matrix and to identify metabolic biomarkers of S. enteritidis in chicken. The UHPLC-QTRAP-MS high-throughput targeted metabolomics approach was employed to analyze the metabolic profiles of contaminated and control group chickens. A total of 348 metabolites were quantified, and the application of deep learning least absolute shrinkage and selection operator (LASSO) modelling analysis obtained eight potential metabolite biomarkers for S. enteritidis. Metabolic abundance change analysis revealed significantly enriched abundances of anthranilic acid, l-pyroglutamic acid, 5-hydroxylysine, n,n-dimethylarginine, 4-hydroxybenzoic acid, and menatetrenone in contaminated chicken samples. The receiver operating characteristic (ROC) curve analysis demonstrated the strong ability of these six metabolites as biomarkers to distinguish S. enteritidis contaminated and fresh chicken samples. The findings presented in this study offer a theoretical foundation for developing an innovative approach to identify and detect foodborne contamination caused by S. enteritidis.

A 3D-Printed Electrochemical Immunosensor Employing Cd/Se ZnS QDs as Labels for the Rapid and Ultrasensitive Detection of Salmonella typhimurium in Poultry Samples

Salmonella is one of the leading causes of foodborne illnesses worldwide, with poultry products being a major source of contamination. Thus, the detection of salmonella in commercial poultry products is crucial to minimize the effects on public health. Electrochemical sensors are promising tools for bacteria detection due to their sensitivity, simplicity, and potential for on-site analysis. In this work, a three-dimensional (3D) printed electrochemical immunosensor for the determination of Salmonella typhimurium in fresh chicken through a sandwich immunoassay employing biotinylated anti-S. typhimurium antibody followed by streptavidin labeled with Cd/Se ZnS quantum dots (QDs) is presented. The device features three carbon-black polylactic acid electrodes and a holder, and the quantification of S. typhimurium is performed by anodic stripping voltametric (ASV) determination of the Cd(II) released after acidic dissolution of the QDs. To enhance sensitivity, an electroplated bismuth film was deposited on the working electrode, achieving a detection limit of 5 cfu/mL in a total assay time of 25 min, whereas 5 h of sample pre-enrichment was required for the detection of 1 cfu/25 mL of chicken rinse and chicken broth. The method is accurate, with %recovery values ranging from 93.3 to 113% in fresh chicken samples, and repeatable with intra- and inter- assay coefficient of variations <2 and 5%, respectively, indicating the suitability of the proposed immunosensor for the detection of S. typhimurium at the point-of-need.

Untargeted and targeted metabolomics identify metabolite biomarkers for Salmonella enteritidis in chicken meat

Salmonella Enteritidis easily contaminate chicken during slaughtering, processing, transportation, and sales, which seriously endangers human health. This study aimed to identify metabolite biomarkers for Salmonella Enteritidis contamination in chicken meat. UPLC-Q-Orbitrap MS untargeted metabolomics analysis identified 441 and 240 confidently metabolites in positive and negative ion mode, respectively. Thirty metabolites were defined as potential biomarkers for Salmonella enteritidis contamination in chicken meat. UPLC-QQQ-MS based targeted metabolomics was used to quantitatively analyze candidate metabolite biomarkers in Salmonella enteritidis contaminated and fresh chicken samples. A total of 10 candidate metabolite biomarkers were confirmed in the validation set, among which acetylcholine, l-Methionine, l-Proline, l-Valine, and l-Norleucine were identified as biomarkers for Salmonella Enteritidis contamination in chicken. The combined receiver operating characteristic curve analysis of the five biomarkers achieved an AUC of 0.956, indicating their high sensitivity and specificity in predicting Salmonella Enteritidis in raw chicken. In conclusion, the present study identified five metabolite biomarkers for Salmonella enteritidis in raw chicken. These results provide a potential theoretical basis for developing Salmonella Enteritidis detection methods in raw chicken.

Combination effect of Alpinia malaccensis and Terminalia catappa extract for controlling foodborne pathogens and spoilage bacteria on ready to cook vacuum packed raw chicken meat

AbstractThe combined antibacterial activity of Alpinia malaccensis and Terminalia catappa, was tested for Listeria monocytogenes, Staphylococcus aureus and spoilage bacteria in vacuum packed ready‐to‐cook (RTC) chicken. The 10 g of chicken pieces were inoculated with each bacterium and marinated with 0.5 ml of the mixture of 5 mg/ml A. malaccensis and 20 mg/ml T. catappa. The chicken was vacuum packed after adding 1 ml extract mixture and stored at 4 or 8 °C for 12 days. Every three‐day intervals microbial count, lipid oxidation, pH, and the color was determined. Combination of plant extracts significantly (p < .05) inhibited the growth of S. aureus bacteria with 1.80, 2.13, 2.36, and 2.97 log CFU/g reduction over 3, 6, 9, and 12 days stored at 8 °C. Similarly, L. monocytogenes was significantly (p < .05) inhibited at 6, 9, 12 days with 1.22, 1.60, and 1.55 log CFU/g reduction compared to control at 4 °C. Lipid oxidation significantly reduced (p < .05) in treated chicken 1.39 MDA mg/kg and 2.43 MDA mg/kg at day 12 at 4 and 8 °C, respectively. Total plate count of treated chicken showed 6.59 ± 0.10 log CFU/g at 6 days of storage at 4 °C and 6.66 ± 0.36 CFU/g during 9 days of storage at 8 °C allowing safe for human consumption.Practical applicationsThe shelf‐life of RTC marinated vacuum packed fresh chicken samples stored at 4 and 8 °C were significantly extended for 6 and 9 days, respectively. Plant extracts combination showed a significant inhibition of L. monocytogenes or S. aureus and spoilage bacteria and reduced lipid oxidation. Therefore, two plants extract combinations act as antimicrobials and antioxidants which could stabilize lipid oxidation, color, and microbial growth thus extending the shelf‐life of ready to cook fresh chicken meat products. Therefore, marinated RTC chicken is economically important for the food industry.

English

Oligonucleotide array hybridisation and multiplex polymerase chain reaction (m-PCR) can be used to screen and detect multiple foodborne pathogens. In our study, m-PCR and oligonucleotide array assays for the specific detection of the dominant foodborne bacterial pathogens, including Escherichia coli, Listeria monocytogenes, Salmonella spp., andShigella spp., in chicken meat were developed. The combination of m-PCR and an oligonucleotide array targeting the 16S rRNA, uspA, prfA, fimY, and ipaH genes displayed a high discriminatory power among the aforementioned genera and species with low or no incidence of false negative results. Our combined methods could detect all 4 target bacteria at amounts as low as 1 ng of each from mixed genomic DNA extracted from pure cultures, which is equivalent to 104-106 CFU/ml. After enrichment steps for the target bacteria, E. coli, L. monocytogenes, and Salmonella sp. could be detected simultaneously from fresh chicken samples. Combining the two methods could enhance accuracy and sensitivity for foodborne pathogen detection and identification. The problems of cross-reactivities from non-target bacteria isolated from an enrichment culture and the difficulties in result interpretation by m-PCR could be solved using our oligonucleotide array hybridisation method.   Key words: Oligonucleotide array, multiplex PCR, foodborne pathogens, target bacteria.

Development of a DNA macroarray for simultaneous detection of multiple foodborne pathogenic bacteria in fresh chicken meat

A DNA macroarray was developed to provide the ability to detect multiple foodborne pathogens in fresh chicken meat. Probes targeted to the 16S rRNA and genus- and species-specific genes, including fimY, ipaH, prfA, and uspA, were selected for the specific detection of Salmonella spp., Shigella spp., Listeria monocytogenes, and Escherichia coli, respectively. The combination of target gene amplification by PCR and a DNA macroarray in our system was able to distinguish all target bacteria from pure cultures with a detection sensitivity of 10⁵ c.f.u. ml⁻¹. The DNA macroarray was also applied to 10 fresh chicken meat samples. The assay validation demonstrated that by combining the enrichment steps for the target bacteria and the DNA macroarray, all 4 target bacteria could be detected simultaneously from the fresh chicken samples. The sensitivity of L. monocytogenes and Shigella boydii detection in the fresh chicken samples was at least 10 and 3 c.f.u. of the initial contamination in 25 g samples, respectively. The advantages of our developed protocol are high accuracy and time reduction when compared to conventional culture. The macroarray developed in our investigation was cost effective compared to modern oligonucleotide microarray techniques because there was no expensive equipment required for the detection of multiple foodborne pathogens.

USE OF A CONTROLLED CHLORINE DIOXIDE (CLO2) RELEASE SYSTEM IN COMBINATION WITH MODIFIED ATMOSPHERE PACKAGING (MAP) TO CONTROL THE GROWTH OF PATHOGENS

ABSTRACT Salmonella Typhimurium and Listeria monocytogenes are major bacterial pathogens associated with poultry products. A controlled released ClO2 sachet applied with modified atmosphere packaging (MAP) was evaluated for its ability to control the growth of S. Typhimurium and L. monocytogenes on raw chicken breast during refrigerated storage. The fresh chicken samples were inoculated with one or the other of the pathogens at 104 cfu/g, and the packages (with and without ClO2 sachet) were flushed with ambient air or 30% CO2/70% N2 before sealing, and then stored at 4C for up to 21 days. The maximum reduction in MAP plus ClO2 (compared with MAP alone) was 0.68 log cfu/g for S. Typhimurium and 1.87 log cfu/g for L. monocytogenes. Color and pH changes of the chicken breast were observed at 8 µg/h of ClO2 during the storage period.PRACTICAL APPLICATIONSWe think that the results of the study with the combined treatment of chlorine dioxide (ClO2) and modified atmosphere packaging may enhance the effectiveness of antimicrobials, reduce the amount of agent needed, and decrease the risk of off‐flavors. The applications of the results will be useful for poultry industry to give the significant improvement in shelf life for packaged fresh products.

Incidence of tetracycline residues in chicken meat and liver retailed to consumers

The incidence of tetracyclines’ (TCs) residue (oxytetracycline, tetracycline, chlorotetracycline and doxycycline) in fresh chicken samples (meat and liver) collected during one year was recorded. TC residues were analysed using an HPLC-DAD method. The limit of detection for meat was 4.4, 5, 10 and 7 ng g−1 for OTC, TTC, CTC and DOC, respectively, compared with 5.5, 6, 12 and 9 ng g−1 stated for liver. The recovery of the method ranged from 91% to 70% depending upon both matrix type and tetracycline kind. The results revealed that 66 (44%) samples contained TC residues including 21 (42%) breast, 19 (38%) thigh and 26 (52%) liver samples. The corresponding contaminated ranges were 124–5812, 107–6010 and 103–8148 µg kg−1. A total of 12 (8%), 13 (7.33%) and 20 (13.33%) samples of breast, thigh and liver, respectively, had TC residues above the Codex maximum residue limit (MRL). Liver samples had a higher incidence and level than those found in breast or thigh samples.

Simultaneous Detection and Differentiation of Campylobacter jejuni, C. coli, and C. lari in Chickens Using a Multiplex Real-Time PCR Assay

A multiplex real-time PCR (qPCR) assay was developed for simultaneous detection and differentiation of the three most important Campylobacter species in chickens. Three novel sets of PCR primers and TaqMan probes were designed to amplify the unique DNA sequences within the hipO, cdtA, and pepT genes which are specific to Campylobacter jejuni, Campylobacter coli, and Campylobacter lari, respectively. To avoid competition in the multiple target amplifications, the concentrations of primers and probes were optimized. By using the optimized qPCR conditions together with a minor-groove binding probe of pepT, amplification efficiency greater than 92% and detection sensitivity of 38 genome copies/reaction have been achieved for all three targets. The assay was highly specific for C. jejuni, C. coli, and C. lari with testing of 33 Campylobacter strains and 20 non-Campylobacter strains. In chicken samples spiked with known quantities of Campylobacter cells, the assay was able to detect 1 CFU/g after a 24-h enrichment. Application of the assay in food was further evaluated using 21 fresh chicken samples obtained from local supermarkets. The results revealed that, after a 24-h or 48-h enrichment, 14 samples (66.7%) were positive for C. jejuni, five samples (23.8%) were positive for C. coli, and none of the samples was contaminated by C. lari. Taken together, the multiplex qPCR assay combined with an enrichment step is a sensitive, species-specific, and non-labor-intensive method suitable for rapid detection of C. jejuni, C. coli, and C. lari in chicken samples.

Active Packaging of Fresh Chicken Breast, with Allyl Isothiocyanate (AITC) in Combination with Modified Atmosphere Packaging (MAP) to Control the Growth of Pathogens

Listeria monocytogenes and Salmonella typhimurium are major bacterial pathogens associated with poultry products. Ally isothiocyanate (AITC), a natural antimicrobial compound, is reportedly effective against these pathogenic organisms. A device was designed for the controlled release of AITC with modified atmosphere packaging (MAP), and then evaluated for its ability to control the growth of L. monocytogenes and S. typhimurium on raw chicken breast during refrigerated storage. In order to obtain controlled release during the test period, a glass vial was filled with AITC and triglyceride. It was then sealed using high-density polyethylene film. The release of AITC was controlled by the concentration (mole fraction) of AITC in the triglyceride and by the AITC vapor permeability through the film. The fresh chicken samples were inoculated with one or the other of the pathogens at 10(4) CFU/g, and the packages (with and without AITC-controlled release device) were flushed with ambient air or 30% CO(2)/70% N(2) before sealing, and then stored at 4 degrees C for up to 21 d. The maximum reduction in MAP plus AITC (compared to MAP alone) was 0.77 log CFU/g for L. monocytogenes and 1.3 log CFU/g for S. typhimurium. The color of the chicken breast meat was affected by the concentration of AITC. Overall, a release rate of 0.6 microg/h of AITC was found to not affect the color, whereas at 1.2 microg/h of AITC the surface of the chicken was discolored.

Evaluación de la calidad de diferentes tipos de carne de pollo que se consumen en Puerto Rico

Se llevo a cabo un estudio para comparar la calidad general, microbiología y duración en almacén de pollos frescos y congelados. Se compararon dos marcas de pollo congelado Grado A, una de Grado C y una marca de pollo fresco para rendimiento, textura, aceptabilidad general, contenido de bacterias sicrotróficas luego de 1, 2 y 3 ciclos de descongelación y congelación y la duración en almacén una vez los pollos se descongelaron y se mantuvieron a 7.2° C. (45° F.). A manera de testigo, se analizó también un grupo de muestras sin congelar para bacterias sicrotróficas y duración en almacén. No encontramos diferencias significativas (P> 0.05) en rendimiento, textura y aceptabilidad general entre las muestras de pollo fresco y congelado. La abundancia de bacterias sicrotróficas generalmente no se afecto hasta por 3 ciclos de descongelación y congelación. Con la excepción de los pollos Grado C, la duración en almacen generalmente no se afectó por hasta 3 ciclos de descongelación y congelación al compararla con la de las muestras que nunca se congelaron o que se congelaron y descongelaron sólo una vez.

Serotyping of Campylobacter jejuni from an outbreak of enteritis implicating chicken

An outbreak of campylobacter enteritis involving 7 of 17 people over a period of 5 days followed a dinner at a restaurant. A chicken casserole dish was implicated with a food-specific attack rate of 58%. Campylobacter jejuni Penner serotype 18/21/29, resistant to metronidazole, was isolated from 3 of 4 symptomatic patients and from three raw fresh chicken samples closely associated with the implicated chicken. Numbers of C. jejuni in the chicken ranged from 5.3 X 10(1) to 7.5 X 10(2) colony forming units per square centimeter of surface area. This is the first outbreak of campylobacter enteritis reported in Australia in which C. jejuni has been isolated from both human and food sources and the isolates serologically confirmed as identical.