Monitoring of meat quality and change-point detection by a sensor array and profiling of bacterial communities.

BACKGROUND: Real-time monitoring of food consumer quality remains challenging due to diverse bio-chemical processes taking place in the food matrices, and hence it requires accurate analytical methods. Thresholds to determine spoiled food are often difficult to set. The existing analytical methods are too complicated for rapid in situ screening of foodstuff. RESULTS: We have studied the dynamics of meat spoilage by electronic nose (e-nose) for digitizing the smell associated with volatile spoilage markers of meat, comparing the results with changes in the microbiome composition of the spoiling meat samples. We apply the time series analysis to follow dynamic changes in the gas profile extracted from the e-nose responses and to identify the change-point window of the meat state. The obtained e-nose features correlate with changes in the microbiome composition such as increase in the proportion of Brochothrix and Pseudomonas spp. and disappearance of Mycoplasma spp., and with representative gas sensors towards hydrogen, ammonia, and alcohol vapors with R2 values of 0.98, 0.93, and 0.91, respectively. Integration of e-nose and computer vision into a single analytical panel improved the meat state identification accuracy up to 0.85, allowing for more reliable meat state assessment. SIGNIFICANCE: Accurate identification of the change-point in the meat state achieved by digitalizing volatile spoilage markers from the e-nose unit holds promises for application of smart miniaturized devices in food industry.

Colorimetric aptasensor for Listeria monocytogenes detection using dual functional Fe3O4@MIL-100(Fe) with magnetic separation and oxidase-like activities in food samples.

A novel colorimetric aptasensor assay based on the excellent magnetic responsiveness and oxidase-like activity of Fe3O4@MIL-100(Fe) was developed. Fe3O4@MIL-100(Fe) absorbed with aptamer and blocked by BSA served as capture probe for selective isolation and enrichment of Listeria monocytogenes one of the most common and dangerous foodborne pathogenic bacteria. The aptamer absorbed on Fe3O4@MIL-100(Fe) was further used as signal probe that specifically binds with target bacteria conjugation of capture probe for colorimetric detection of Listeria monocytogenes, taking advantages of its oxidase-like activity. The linear range of the detection of Listeria monocytogenes was from 102 to 107 CFU mL-1, with the limit of detection as low as 14 CFU mL-1. The approach also showed good feasibility for detection of Listeria monocytogenes in milk and meat samples. The spiked recoveries were in the range 81-114% with relative standard deviations ranging from 1.28 to 5.19%. Thus, this work provides an efficient, convenient, and practical tool for selective isolation and colorimetric detection of Listeria monocytogenes in food.

Salmonella Prevalence and antibiotic resistance profile in raw poultry meat sold in North Lebanon: Insights from the COVID-19 pandemic and economic crisis.

Salmonella-related foodborne illness is a significant public health concern, with the primary source of human infection being animal-based food products, particularly chicken meat. Lebanon is currently experiencing a dual crisis: the COVID-19 pandemic and an unprecedented economic crisis, which has resulted in substantial challenges to the public health system and food safety. This study aims to assess the prevalence and antibiotic resistance profile of Salmonella in raw poultry meat sold in North Lebanon during this dual crisis. A cross-sectional study was carried out between May 2021 and April 2022 across six different districts in North Lebanon. A total of 288 whole, unprocessed chickens were examined. The isolation and identification of Salmonella isolates were done based on cultural and biochemical properties. All isolates were subjected to antimicrobial susceptibility testing and phenotypic assays for Extended-Spectrum Beta-lactamase (ESBL) detection. The prevalence of Salmonella in raw poultry meat purchased in North Lebanon reached 18.05 % (52/288). The dry season and chilled chicken were significantly associated with an increased risk of Salmonella contamination (P < 0.05). Additionally, 34.61 % of the isolates were potential ESBL producers, and 57.69 % exhibited multidrug resistance (MDR). This study highlights the existence of MDR in chicken meat in North Lebanon, posing a potential health risk if undercooked chicken meat is consumed. This emphasizes the importance of the implementation of preventive strategies and hygienic procedures throughout the food chain to reduce the risk of Salmonella spp. contamination in chicken meats and its potential transmission to humans.

High prevalence and transmission of blaNDM-positive Escherichia coli between farmed ducks and slaughtered meats: An increasing threat to food safety.

The emergence of carbapenem-resistant bacteria especially carbapenem-resistant Escherichia coli (CREC) in food animals poses a serious threat to food safety and public health. Reports about the dissemination of carbapenem-resistant bacteria along the food animal production chain are scattered and mainly focus on swine and chicken. Abuse of antibiotics in duck farms is common especially in China which has the largest duck production industry, however, the CREC transmission between farmed ducks and slaughtered meats remains unclear and the role of slaughterhouse in disseminating CREC among duck meats remains largely unknown. Herein, we collected 251 fecal samples from five typical duck farms along with 125 slaughtered meat samples (25 from each farm) in the corresponding slaughterhouse in Anhui Province, China, in December 2018. All samples were screened for CREC isolates which were analyzed for the presence of carbapenemase genes and colistin resistance gene mcr. The resistance profiles, transferability, pulsed-field gel electrophoresis (PFGE), whole-genome sequencing and phylogenetic analysis of the CREC isolates from both ducks and meats were further characterized. This is the first report presenting the high prevalence of blaNDM-positive CREC isolates in ducks from duck farms (57.8 %) and slaughtered meats (33.6 %) in the corresponding slaughterhouse. Among the 203 blaNDM-positive CREC isolates obtained in this study, 19.2 % harbored mcr-1 and all CREC isolates showed resistance to nearly all currently available antibiotics (except tigecycline). Of note, mcr-1 was found in 17.8 % of the meat-derived CREC carrying blaNDM. Based on the PFGE analysis, clonal spread of blaNDM-positive CREC including some also carrying mcr-1 was found between farmed ducks and slaughtered duck meats even from different farms. Special attention should be paid to the clonal dissemination of meat-derived CREC within the slaughterhouse, which contributed to the high prevalence of blaNDM in slaughtered meats. Additionally, horizontal transmission mainly mediated by transferable blaNDM-5-bearing IncX3 plasmids, untypable blaNDM-1-bearing plasmids and mcr-1-bearing IncHI2 plasmids further facilitated the rapid spread of such multidrug-resistant strains. Notably, the blaNDM-bearing plasmids and mcr-1-bearing plasmids in CREC from meats were highly similar to those from animals and humans. More worryingly, the phylogenomic analysis showed that CREC isolates from both ducks and corresponding meats clustered with previously reported human CREC isolates carrying mcr-1 in different geographical areas including China. These findings further prove that the CREC and resistance plasmids in farmed ducks could transmit to meats even from different farms via the slaughterhouse and then trigger infections in humans. The high prevalence and clonal transmission of CREC isolates including those also carrying mcr-1 between ducks and meats are alarming, and urgent control measures are required to reduce the dissemination of such organisms.

Effect of Rheum ribes L. pulp enriched with eugenol or thymol on survival of foodborne pathogens and quality parameters of chicken breast fillets.

The aim of this study was to characterize the pulp of Rheum ribes L. and to determine the effect of the pulp enriched with eugenol (1 %) or thymol (1 %) on the microbiological and physico-chemical quality of chicken breast fillets. Chicken breast fillets, inoculated with Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium, and Escherichia coli O157:H7 (~6.0 log10), were marinated for 24 h in a mixture prepared from a combination of Rheum ribes L. pulp with eugenol or thymol. The quality parameters were analyzed for 15 days at +4 °C. The Rheum ribes L. pulp was found to have high antioxidant activity, high total phenolic content and contained 22 different phenolic substances, among which rutin ranked first. The pulp contained high levels of p-xylene and o-xylene as volatile substances and citric acid as an organic acid. The combination of Pulp + Eugenol + Thymol (PET) reduced the number of pathogens in chicken breast fillets by 2.03 to 3.50 log10 on day 0 and by 2.25 to 4.21 log10 on day 15, compared to the control group (P < 0.05). The marinating treatment significantly lowered the pH values of fillet samples on the first day of the study, compared to the control group (P < 0.05). During storage, TVB-N levels showed slower increase in the treatment groups compared to the control group (P < 0.05). In addition, the marinating process led to significant changes in physicochemical parameters such as water holding capacity, color, texture, cooking loss, and drip loss compared to the control group (P < 0.05). In conclusion, the results of this study showed that the pulp of Rheum ribes L., which has a high antioxidant capacity and contains various bioactive compounds. Furthermore, S. Typhimurium, E. coli O157:H7 and L. monocytogenes were inhibited considerably by marinating Rheum ribes L. pulp with a combination of eugenol and thymol.

High Campylobacter diversity in retail chicken: epidemiologically important strains may be missed with current sampling methods.

Campylobacter spp. are leading bacterial gastroenteritis pathogens. Infections are largely underreported, and the burden of outbreaks may be underestimated. Current strategies of testing as few as one isolate per sample can affect attribution of cases to epidemiologically important sources with high Campylobacter diversity, such as chicken meat. Multiple culture method combinations were utilized to recover and sequence Campylobacter from 45 retail chicken samples purchased across Norwich, UK, selecting up to 48 isolates per sample. Simulations based on resampling were used to assess the impact of Campylobacter sequence type (ST) diversity on outbreak detection. Campylobacter was recovered from 39 samples (87%), although only one sample was positive through all broth, temperature, and plate combinations. Three species were identified (Campylobacter jejuni, Campylobacter coli, and Campylobacter lari), and 33% of samples contained two species. Positive samples contained 1-8 STs. Simulation revealed that up to 87 isolates per sample would be required to detect 95% of the observed ST diversity, and 26 isolates would be required for the average probability of detecting a random theoretical outbreak ST to reach 95%. An optimized culture approach and selecting multiple isolates per sample are essential for more complete Campylobacter recovery to support outbreak investigation and source attribution.

Efficiency of using lactic acid and beefxide to reduce indicator microorganisms on beef in Mosul slaughterhouse.

Background: Meat contamination occurs in various ways, the most important of which are live animals before slaughter and the slaughter process (de-hiding and evisceration). For this, many substances were used that have an antimicrobial effect and can disinfect the surfaces of the carcass and extend its shelf life. Aim: This research aimed to study the efficiency of using some organic acids (lactic acid and beefxide) to reduce the microbial load (indicator microorganisms) on the surfaces of beef carcasses and some edible organs in the Mosul slaughterhouse. Methods: Two hundred sixty-four swabs (192 carcasses + 72 edible organ samples) were collected over the course of three months from the Mosul slaughterhouse in Nineveh Governorate between September 2023, and December 2023 (132 treated with organic acids and 132 not treated). The petrifilm method was used to detect indicator microorganisms in the samples. Results: Our results showed that the contamination rate in beef carcasses with generic Escherichia coli, coliforms, total coliform counts, and Enterobacteriaceae before treatment was 0.81, 1.22, 1.48, and 1.38 mean log colony forming unit (CFU/cm2), respectively. While the contamination rate in samples treated with organic acids for generic E. coli, coliforms, total coliform counts, and Enterobacteriaceae was -0.1, 0.31, 0.45, and 0.41 mean log CFU/cm2, respectively. Moreover, the level of contamination with indicator microorganisms in edible organs treated with organic acids was lower compared to untreated samples. Even though there was contamination with indicator microorganisms in the liver, heart, and kidney, there was no "significant" difference between them. Whereas there was no significant difference (p > 0.05) between lactic acid and beefxide solution in terms of reducing the rate of contamination of the indicator microorganisms in carcasses and the edible organs samples. Regarding the type of swabs used in the study, the results showed the effectiveness of sponge swabs, as the rate of microbial recovery (indicator microorganisms) was higher (p < 0.01) compared to cotton swabs. Conclusion: The study demonstrated the efficiency of using organic acids (lactic acid and beefxide solution) in reducing the microbial load to a level that does not cause diseases.

Dynamics of microbiome and resistome in a poultry burger processing line.

Traditionally, surveillance programs for food products and food processing environments have focused on targeted pathogens and resistance genes. Recent advances in high throughput sequencing allow for more comprehensive and untargeted monitoring. This study assessed the microbiome and resistome in a poultry burger processing line using culturing techniques and whole metagenomic sequencing (WMS). Samples included meat, burgers, and expired burgers, and different work surfaces. Microbiome analysis revealed spoilage microorganisms as the main microbiota, with substantial shifts observed during the shelf-life period. Core microbiota of meat and burgers included Pseudomonas spp., Psychrobacter spp., Shewanella spp. and Brochothrix spp., while expired burgers were dominated by Latilactobacillus spp. and Leuconostoc spp. Cleaning and disinfection (C&D) procedures altered the microbial composition of work surfaces, which still harbored Hafnia spp. and Acinetobacter spp. after C&D. Resistome analysis showed a low overall abundance of resistance genes, suggesting that effective interventions during processing may mitigate their transmission. However, biocide resistance genes were frequently found, indicating potential biofilm formation or inefficient C&D protocols. This study demonstrates the utility of combining culturing techniques and WMS for comprehensive of the microbiome and resistome characterization in food processing lines.

The challenges and prospects of using cold plasma to prevent bacterial contamination and biofilm formation in the meat industry.

The risk of foodborne disease outbreaks increases when the pathogenic bacteria are able to form biofilms, and this presents a major threat to public health. An emerging non-thermal cold plasma (CP) technology has proven a highly effective method for decontaminating meats and their products and extended their shelf life. CP treatments have ability to reduce microbial load and, biofilm formation with minimal change of color, pH value, and lipid oxidation of various meat and meat products. The CP technique offers many advantages over conventional processing techniques due to its layout flexibility, nonthermal behavior, affordability, and ecological sustainability. The technology is still in its infancy, and continuous research efforts are needed to realize its full potential in the meat industry. This review addresses the basic principles and the impact of CP technology on biofilm formation, meat quality (including microbiological, color, pH value, texture, and lipid oxidation), and microbial inactivation pathways and also the prospects of this technology.

Comparative genomics of quinolone-resistant Escherichia coli from broilers and humans in Norway.

BACKGROUND: The usage of fluoroquinolones in Norwegian livestock production is very low, including in broiler production. Historically, quinolone-resistant Escherichia coli (QREC) isolated from Norwegian production animals rarely occur. However, with the introduction of a selective screening method for QREC in the Norwegian monitoring programme for antimicrobial resistance in the veterinary sector in 2014; 89.5% of broiler caecal samples and 70.7% of broiler meat samples were positive. This triggered the concern if there could be possible links between broiler and human reservoirs of QREC. We are addressing this by characterizing genomes of QREC from humans (healthy carriers and patients) and broiler isolates (meat and caecum). RESULTS: The most frequent mechanism for quinolone resistance in both broiler and human E. coli isolates were mutations in the chromosomally located gyrA and parC genes, although plasmid mediated quinolone resistance (PMQR) was also identified. There was some relatedness of the isolates within human and broiler groups, but little between these two groups. Further, some overlap was seen for isolates with the same sequence type isolated from broiler and humans, but overall, the SNP distance was high. CONCLUSION: Based on data from this study, QREC from broiler makes a limited contribution to the incidence of QREC in humans in Norway.

Prevalence and types of methicillin-resistant Staphylococcus aureus (MRSA) in meat and meat products from retail outlets and in samples of animal origin collected in farms, slaughterhouses and meat processing facilities. A review.

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of nosocomial and community infections, in some cases severe and difficult to treat. In addition, there are strains of MRSA that are specifically associated with food-producing animals. For this reason, in recent years special attention has been paid to the role played by foodstuffs of animal origin in infections by this microorganism. With the aim of gaining knowledge on the prevalence and types of MRSA in meat and meat products, a review was undertaken of work published on this topic since 2001, a total of 259 publications, 185 relating to meat samples from retail outlets and 74 to samples of animal origin collected in farms, slaughterhouses and meat processing facilities. Strains of MRSA were detected in 84.3% reports (156 out of 185) from retail outlets and 86.5% reports (64 out of 74) from farms, slaughterhouses and meat processing facilities, although in most of the research this microorganism was detected in under 20% of samples from retail outlets, and under 10% in those from farms, slaughterhouses and meat processing facilities. The meat and meat products most often contaminated with MRSA were pork and chicken. In addition to the mecA gene, it is crucial to take into consideration the mecB and mecC genes, so as to avoid misidentification of strains as MSSA (methicillin-susceptible Staphylococcus aureus). The great variety of methods used for the determination of MRSA highlights the need to develop a standardized protocol for the study of this microorganism in foods.

Multiplex PCR-based genotyping of Salmonella Enteritidis and Salmonella Typhimurium from food sources and assessment of their antimicrobial resistance profiles in Egypt.

BACKGROUND: Salmonellosis is a widespread zoonotic disease that poses a significant threat to livestock and public health. This study aimed to serotype 20 Salmonella isolates obtained from sixty retail chicken meats, assess Salmonella contamination from eggs, and evaluate antibiotic resistance profiles. METHODS AND RESULTS: Twenty eggs were randomly collected in the new Borg El Arab market. Bacterial isolation was carried out utilizing both traditional culture, biochemical, and PCR methods. Among the twenty eggs analyzed, three (15%) tested positive for Salmonella, while the remaining seventeen (85%) were confirmed as negative. Genotyping through multiplex PCR revealed the presence of two S. Enteritidis and other serovar, with the use of three specific gene sets: a random sequence for Salmonella spp., sdfI gene for S. Enteritidis, and flagellin (fliC gene) for S. Typhimurium. Out of the 20 isolates obtained from chicken meat, five (25%) were identified as S. Typhimurium, and three (15%) were classified as S. Enteritidis. All isolates sourced from chicken meat exhibited resistance to Rifampicin and Amoxicillin, with 90% displaying sensitivity to cefotaxime, gemifloxacin, and Erythromycin. Importantly, S. Blegdam, identified via serological methods, displayed resistance to all tested antibiotics. For the three isolates obtained from eggs, 66.6% showed sensitivity to cefotaxime, erythromycin, cefuraxime, and cefaclor, while displaying complete resistance (100%) to Amoxicillin, rifampicin, clarithromycin, and cefadroxil. Notably, one serovar exhibited absolute resistance to all tested drugs. CONCLUSION: Stakeholders must implement strict control measures and rationalize antibiotic use in veterinary and human medicine due to the rise of antibiotic-resistant strains.

Food safety control in poultry industry: prevalence and antimicrobial susceptibility of Escherichia coli isolated from raw chicken and the potential use of Origanum essential oils as alternative to antibiotics.

1. The extensive use of antimicrobials in poultry production may contribute to the emergence of resistant bacteria. This study was conducted to determine the prevalence and resistance of different E. coli strains isolated from raw chicken meat and to investigate the possibility to use Lebanese native oregano essential oils as alternatives.2. In total, 250 chickens from Lebanese markets were examined for the presence of E. coli. Isolates were then screened for susceptibility using 19 antibiotics and two essential oils extracted from oregano plants.3. Of the 250 chickens tested, 80% were contaminated with E. coli. Main resistance was seen against amoxycillin, ampicillin, penicillin, tetracycline, tylosin, streptomycin and erythromycin. The highest rate of sensitivity was found in 86.1% of strains to Amoxycillin/Clavulanic acid, 80.09% to Tilmicosin. Both essential oils from Origanum syriacum (98%) and O. ehrenbergii (97.3%) showed promising potential in inhibiting the growth of the tested bacteria. Oil from O. syriacum exhibited superior efficacy against 200 E. coli strains, inhibiting 46.1% at 200 mg/l and all at 400 mg/l, while O. ehrenbergii oil showed slightly lower inhibition, affecting 41.6% at 200 mg/l and all at 400 mg/l.

Isolation, whole genome sequencing and application of a broad-spectrum Salmonella phage.

Salmonella is considered as one of the most common zoonotic /foodborne pathogens in the world. The application of bacteriophages as novel antibacterial agents in food substrates has become an emerging strategy. Bacteriophages have the potential to control Salmonella contamination.We have isolated and characterized a broad-spectrum Salmonella phage, SP154, which can lyse 9 serotypes, including S. Enteritidis, S. Typhimurium, S. Pullorum, S. Arizonae, S. Dublin, S. Cholerasuis, S. Chester, S. 1, 4, [5], 12: i: -, and S. Derby, accounting for 81.9% of 144 isolates. SP154 showed a short latent period (40 min) and a high burst size (with the first rapid burst size at 107 PFUs/cell and the second rapid burst size at approximately 40 PFUs/cell). Furthermore, SP154 activity has higher survival rates across various environmental conditions, including pH 4.0-12.0 and temperatures ranging from 4 to 50 °C for 60 min, making it suitable for diverse food processing and storage applications. Significant reductions in live Salmonella were observed in different foods matrices such as milk and chicken meat, with a decrease of up to 1.9 log10 CFU/mL in milk contamination and a 1 log10 CFU/mL reduction in chicken meat. Whole genome sequencing analysis revealed that SP154 belongs to the genus Ithacavirus, subfamily Humphriesvirinae, within the family Schitoviridae. Phylogenetic analysis based on the terminase large subunit supported this classification, although an alternate tree using the tail spike protein gene suggested affiliation with the genus Kuttervirus, underscoring the limitations of relying on a single gene for phylogenetic inference. Importantly, no virulence or antibiotic resistance genes were detected in SP154. Our research highlights the potential of using SP154 for biocontrol of Salmonella in the food industry.

Characteristics of changes in volatile organic compounds and bacterial communities in physically preserved pigeon breast meat.

To understand the relationship between changes in aroma and bacteria in pigeon breast meat (PBM) during preservation, bacterial communities and volatile compounds in PBM were analyzed using high-throughput sequencing and gas chromatography-ion mobility spectrometry. Analyses of total viable bacteria counts revealed that modified atmospheric packaging (MAP) and electron beam irradiation (EBI) could be used to extend the shelf-life of PBM to 10 d and 15 d, respectively. Furthermore, Lactococcus spp. and Psychrobacter spp. were the dominant bacterial genera of the MAP and EBI groups, respectively. The results of the study revealed 91 volatile organic compounds, one of which, butanal, was the most intense volatile organic compound while being an important source of aroma differences between the physical preservation techniques. Alpha-terpinolene, acetoin-M, gamma-butyrolactone, 1-hexanol-M, and 2,6-dimethyl-4-heptanone may be markers of PBM spoilage. During preservation, the MA group (treatment with 50 % CO2 + 50 % N2) demonstrated greater stabilization of PBM aroma. A Spearman correlation analysis showed that Lactococcus spp., Psychrobacter spp., and Pseudomonas spp. were the dominant bacterial genera of PBM during preservation and were closely related to an increase in the intensity of anisole, 2-methyl-3-furanthiol, and 5-methyl-2-furanmethanol, respectively. Lactococcus spp. and Psychrobacter spp. play crucial roles in the sensory degradation of PBM. In this study, we analyzed the changes in bacterial genera and volatile organic compounds of PBM under different physical preservation techniques to identify a suitable method for preserving PBM and evaluating its freshness.

Characterization of the prevalence of Salmonella in different retail chicken supply modes using genome-wide and machine-learning analyses.

Salmonella is a foodborne pathogen that causes salmonellosis, of which retail chicken meat is a major source. However, the prevalence of Salmonella in different retail chicken supply modes and the threat posed to consumers remains unclear. The prevalence, serotype distribution, antibiotic resistance, and genomic characteristics of Salmonella in three supply modes of retail chicken (live poultry, frozen, and chilled) were investigated using whole-genome sequencing (WGS) and machine learning (ML). In this study, 480 retail chicken samples from live poultry, frozen, and chilled supply modes in Guangzhou from 2020 to 2021, as well as 253 Salmonella isolates (total isolation rate = 53.1 %), were collected. The prevalence of isolates in the live poultry mode (67.5 %, 81/120) was statistically higher than in the frozen (50.0 %, 120/240) and chilled (43.3 %, 52/120) (P < 0.05) modes. Serotype identification showed significant differences in the serotype distribution of Salmonella in different supply modes. S. Enteritis (46.7 %) and S. Indiana (14.2 %) were predominant in the frozen mode. S. Agona (23.5 %) and S. Saintpaul (13.6 %) were predominant in live poultry, while S. Enteritis (40.4 %) and S. Kentucky (17.3 %) were predominant in chilled mode. Antibiotic testing showed that frozen mode isolates were more resistant; the multidrug-resistant (MDR) rate of isolates in the frozen mode reached 91.8 %, significantly higher than in the chilled (86.5 %) and live (74.1 %) (P < 0.05) modes. WGS was performed on 155 top serotypes (S. Enteritidis, S. Kentucky, S. Indiana, and S. Agona). The antibiotic resistance gene analysis showed that the abundance and carrying rate of antibiotic resistance genes of Salmonella in the frozen mode (54 types, 16.1 %) were significantly higher than in other modes (live poultry: 36 types, 9.4 %, P < 0.05; chilled: 31 types, 11.6 %). The blaNDM-1 and blaNDM-9 genes encoding carbapenem resistance were found in frozen mode isolates on a complex transposon consisting of TnAS3-IS26. Virulence factors and plasmid replicons were abundant in the studied frozen mode isolates. In addition, single nucleotide polymorphism (SNP) phylogenetic tree results showed that in the frozen supply mode, the S. Enteritidis clonal clade continued to contaminate retail chicken meat and was homologous to S. Enteritidis strains found in farm chicken embryos, slaughterhouse chicken carcasses, and patients from hospitals in China (SNP 0 = 10). Notably, the pan-genome-based ML model showed that characteristic genes in frozen and live poultry isolates differed. The narZ gene was a key characteristic gene in frozen isolates, encoding nitrate reductase, relating to anaerobic bacterial growth. The ydgJ gene is a key characteristic gene in the live mode and encodes an oxidoreductase related to oxidative function in bacteria. The high prevalence of live poultry mode Salmonella and the transmission of frozen mode MDR Salmonella in this study pose serious risks to food safety and public health, emphasizing the importance of improving disinfection and cold storage measures to reduce Salmonella contamination and transmission. In conclusion, the continued surveillance of Salmonella across different supply models and the development of an epidemiological surveillance system based on WGS is necessary.

High prevalence and genomic features of multidrug-resistant Salmonella enterica isolated from chilled broiler chicken on retail sale in the United Arab Emirates.

Non-typhoidal Salmonella represents a significant global concern for food safety and One Health. Despite the United Arab Emirates (UAE) being a leading consumer of chicken meat globally, there is a lack of comprehensive understanding regarding the prevalence and genomic characteristics of Salmonella within the country. This study aims to address this gap by conducting a thorough analysis of Salmonella prevalence, antimicrobial resistance, and genomic profiles of isolates obtained from whole broiler carcasses retailed under chilled conditions in the UAE. Our findings reveal that Salmonella was detected in 41.2 % (130/315) of the sampled chilled broiler carcasses, with notable variability observed among samples sourced from six different companies. Phenotypic antimicrobial resistance (AMR) testing, among 105 isolates, highlighted high resistance rates to tetracycline (97.1 %), nalidixic acid (93.3 %), ampicillin (92.4 %), azithromycin (75.2 %), ciprofloxacin (63.8 %), and ceftriaxone (54.3 %). Furthermore, a concerning 99 % (104/105) of the isolates exhibited multidrug resistance. Whole-genome sequencing (WGS) of 60 isolates identified five serovars, with S. infantis/Sequence Type (ST) 32 (55 %) and S. Minnesota/ST-458 (28.3 %) being the most prevalent. WGS analysis unveiled 34 genes associated with antimicrobial resistance, including mcr-1.1 (only in two isolates), conferring resistance to colistin. The two major serovars, Infantis and Minnesota, exhibited significant variation (P-values <0.001) in the distribution of major AMR genes (aadA1, blaCMY-2, blaSHV-12, qnrB19, qnrS1, sul1, and sul2). Notably, the gene qacEdelta, conferring resistance to quaternary ammonium compounds commonly found in disinfectants, was universally present in all S. Infantis isolates (n = 33), compared to only one S. Minnesota isolate. Additionally, all S. Infantis isolates harbored the IncFIB (pN55391) plasmid replicon type. Major serovars exhibited distinct distributions of antimicrobial resistance genes, underscoring the importance of serovar-specific surveillance. These findings emphasize the critical need for continuous surveillance and intervention measures to address Salmonella contamination risks in poultry products, providing valuable insights for public health and regulatory strategies not only in the UAE but also globally.

Limited transmission of carbapenem-resistant Klebsiella pneumoniae between animals and humans: a study in Qingdao.

ABSTRACTDespite no carbapenem use in food animals, carbapenem-resistant Klebsiella pneumoniae (CRKP) perseveres within food animals, rising significant concerns regarding public health risks originating from these non-clinical reservoirs. To investigate the potential link between CRKP in food animals and its infections in humans, we conducted a cross-sectional study encompassing human clinical, meat products, and farm animals, in Qingdao city, Shandong province, China. We observed a relatively higher presence of CRKP among hospital inpatients (7.3%) compared to that in the meat products (2.7%) and farm animals (pig, 4.6%; chicken, 0.63%). Multilocus sequence typing and core-genome phylogenetic analyses confirm there is no evidence of farm animals and meat products in the clinical acquisition of K. pneumoniae isolates and carbapenem-resistant genes. However, potential transmission of K. pneumoniae of ST659 and IncX3 plasmid harbouring blaNDM-5 gene from pigs to pork and farm workers was observed. Our findings suggest a limited role of farm animals and meat products in the human clinical acquisition of K. pneumoniae, and the transmission of K. pneumoniae is more common within settings, than between them.

Sensitive and rapid detection of three foodborne pathogens in meat by recombinase polymerase amplification with lateral flow dipstick (RPA-LFD).

Foodborne illnesses, caused by harmful microorganisms in food, are a significant global health issue. Current methods for identifying these pathogens are both labor-intensive and time-consuming. In this research, we devised a swift and precise detection technique using recombinase polymerase amplification combined with a lateral flow dipstick (RPA-LFD) for three foodborne pathogens found in meat. By employing a dedicated detection device, RPA-LFD allows for the rapid analysis of DNA from Escherichia coli O157 (E. coli O157), Salmonella, and Shigella-pathogens that are prohibited in food. The detection thresholds for E. coli O157, Salmonella, and Shigella are 0.168 fg/µl (1.04 CFU/ml), 0.72 fg/µl (27.49 CFU/ml), and 1.25 fg/µl (48.84 CFU/ml), respectively. This method provides a short detection window, operates at low temperatures, follows simple procedures, and exhibits high sensitivity. Our study establishes the RPA-LFD method for simultaneously identifying the nucleic acid of three foodborne pathogens, offering an efficient solution for quickly identifying multiple contaminants.

Reduction of Campylobacter jejuni contamination by using UVA-LED and sodium hypochlorite on the surface of chicken meat.

Campylobacter jejuni causes gastroenteritis in humans and is a major concern in food safety. Commercially prepared chicken meats are frequently contaminated with C. jejuni, which is closely associated with the diffusion of intestinal contents in poultry processing plants. Sodium hypochlorite (NaClO) is commonly used during chicken processing to prevent food poisoning; however, its antimicrobial activity is not effective in the organic-rich solutions. In this study, we investigated the potential of a new photo-disinfection system, UVA-LED, for the disinfection of C. jejuni-contaminated chicken surfaces. The data indicated that UVA irradiation significantly killed C. jejuni and that its killing ability was significantly facilitated in NaClO-treated chickens. Effective inactivation of C. jejuni was achieved using a combination of UVA and NaClO, even in the organic-rich condition. The results of this study show that synergistic disinfection using a combination of UVA and NaClO has potential beneficial effects in chicken processing systems.