Search Results (914)

Foodborne pathogenic bacteria, like Salmonella spp. and Listeria monocytogenes, can be detected in the primary food production environment. On the other hand, and in the current context of One Health, antimicrobial resistance (AMR) is gaining increased attention worldwide, as it poses significant threat to public health. The purpose of this study was to confirm the presence of Salmonella spp. and L. monocytogenes in pet food and feed samples, by means of biochemical and/or serological testing of the microbial isolates, and then to screen for AMR against a panel of selected antibiotics. Serotyping of the isolates with multiplex polymerase chain reaction revealed the presence of three of the most common clinical Salmonella serovars (S. Enteritidis, S. Typhimurium, S. Thompson) and the major epidemiologically important L. monocytogenes serotypes (1/2a, 1/2b, 1/2c, 4b) in 15 and 9 confirmed isolates of the pathogens, respectively. Strains of Salmonella spp. showed resistance to tetracycline (n = 3) and combined AMR to tetracycline with either ampicillin (n = 2) or trimethoprim-sulfamethoxazole (n = 3), without any multidrug resistance (MDR) being recorded whatsoever. AMR in L. monocytogenes was documented in 55.5% of the bacterial strains (n = 5) tested against ciprofloxacin, meropenem, penicillin, trimethoprim-sulfamethoxazole, and tetracycline. Alarmingly, one strain of L. monocytogenes was MDR to the latter five antibiotics and deemed resistant in three antibiotic groups (carbapenems, penicillins, tetracyclines), after exhibiting minimum inhibitory concentrations (MICs) to meropenem (MIC = 4 μg/mL), penicillin (MIC = 4 μg/mL), and tetracycline (MIC = 48 μg/mL). To the best of our knowledge, finding an MDR L. monocytogenes in pet food is something reported for the first time herein. The results presented in this study highlight the presence of important foodborne bacterial pathogens, such as Salmonella spp. and L. monocytogenes, with increased AMR to antibiotics and possible MDR at the primary production and at the farm level, due to the misuse of pharmacological substances used to treat zoonotic diseases, probably resulting in detection of resistant strains of these pathogenic bacteria in animal-originated food products (e.g., meat, milk, eggs). Full article

Salmonella is a major foodborne pathogen, representing a significant public health concern across the European Union (EU), accounting for 39% of foodborne illness-related hospitalizations in 2022, with the highest rates observed in Romania, Cyprus, Greece, and Lithuania. This pilot study aimed to enhance the surveillance and characterization of Salmonella by implementing both phenotypic and genotypic methods for strain typing, as well as for the detection and confirmation of resistance to ciprofloxacin. Materials and methods: A total of 109 Salmonella strains from acute diarrheal cases in North-Eastern Romania were collected (January–August 2024). From these, 19 representative isolates were selected for molecular characterization, including Multi-Locus Sequence Typing (MLST) and the detection of ciprofloxacin resistance determinants. Whole-Genome Sequencing (WGS) was subsequently performed to confirm serotype identity and resistance markers. Results: The 19 isolates underwent Multi-Locus Sequence Typing (MLST) and ciprofloxacin resistance profiling, with Whole-Genome Sequencing (WGS) for confirmation. MLST identified S. Enteritidis (42.1%) as the predominant serotype, followed by S. Typhimurium, S. Livingstone, and S. Infantis. WGS confirmed serotypes in 15 isolates; 2 showed discrepancies with phenotypic results. Phenotypic resistance to ciprofloxacin was detected in 12/19 (63.2%) of the isolates, 6/12 presenting gyrA mutations (S83Y, D87G), and 2/12 strains presenting the plasmid-mediated qnrB19 gene. Full article

The mutagenic potential of coffee by-products, including Coffea leaves, blossoms, cherries, and silverskin, was studied using thin-layer chromatography (TLC) coupled with the recent planar Ames bioassay via pH indicator endpoint. The 2LabsToGo-Eco allowed for the separation and detection of mutagens in complex samples. Hot water was the most effective extraction solvent in terms of yield and closely simulated the typical human consumption of coffee by-products. Separation was performed on TLC plates with a mixture of ethyl acetate, n-propanol, and water, followed by bioassay detection. The positive control 4-nitroquinoline 1-oxide exhibited clear mutagenic responses, confirming the proper bioassay performance. In the Ames bioautogram, none of the tested coffee by-products showed mutagenic zones, suggesting the absence of strongly acting, acute mutagens under the applied test conditions; however, given the only 5 h short incubation and the use of TA98 strain only, a longer incubation time and testing with additional Salmonella strains is recommended. The results provide new safety data for Coffea leaves and blossoms and are consistent with some previous studies demonstrating the safety of coffee by-products. However, further improvements in the sensitivity and selectivity of the planar Ames bioassay are demanded, and further in vivo and long-term safety studies are recommended. Considering natural variability, the different uses of pesticides and treatments, and the fluctuating supply chains, coffee by-products may differ highly. The planar bioassay technology using the affordable 2LabsToGo-Eco is a powerful toxicological screening option for the coffee industry, considering the increasing interest in utilizing coffee by-products. Full article

Foodborne pathogenic biofilms pose significant challenges to food safety due to their enhanced resistance to conventional antimicrobial agents. In this study, we evaluated the synergistic antibiofilm activity of oregano essential oil (OEO) from Lippia graveolens and the lytic bacteriophage phiLLS against six foodborne bacteria. GC–MS analysis achieved a 100% identification ratio, revealing that OEO was mainly composed of carvacrol (58.9%), p-cymene (28.6%), γ-terpinene (2.9%), and caryophyllene (2.6%). The MIC and MBC of OEO were 1 and 2 mg/mL, respectively, for all strains except E. coli BALL1119 (MIC = 2 mg/mL). We assessed biofilm biomass by crystal violet (CV) staining and metabolic activity using the TTC assay under both individual and combined treatments, monitored 9-hour planktonic growth kinetics to calculate Bliss and HSA synergy indexes, and employed atomic force microscopy (AFM) to visualize nanoscale alterations in Staphylococcus aureus and Escherichia coli BALL1119 biofilms. Combined OEO (2 mg/mL) and phiLLS (MOI 1) treatments achieved significantly greater biofilm biomass reduction than single agents, notably yielding >70% inhibition of S. aureus biofilms (p < 0.05) and a Bliss synergy index of 10.8% in E. coli BALL1119 growth kinetics, whereas other strains were additive. In biofilm assays, S. aureus and Salmonella spp. showed the highest reductions in biomass (CV) (71.0% and 67.8%, ΔHSA = 27.0% and 17.4%; ΔBliss = 21.1% and 13.8%) and metabolic activity (TTC) (68.6% and 48.5%). AFM revealed that OEO alone smoothed the extracellular matrix (averaging a 35% reduction in roughness), whereas the combined treatment caused fracturing (≈68 nm roughness) and prominent lytic pits. Although variability in S. aureus biofilm architecture precluded statistically significant pairwise comparisons, AFM topography and consistent trends in Ra/Rz parameters provided clear visual corroboration of the significant reductions detected by CV and TTC assays. These complementary data indicate that OEO primes the biofilm matrix for enhanced phage-mediated collapse, offering a green, two-step strategy for controlling resilient foodborne biofilms. Full article

Poultry diseases threaten animal welfare and productivity, especially in cage-free systems where communal environments increase disease transmission risks. Traditional diagnostic methods, though accurate, are often labor-intensive, time-consuming, and not suitable for continuous monitoring. This study aimed to develop a web-based disease screening tool to make this process faster and accurate using fecal images. A publicly available dataset consisting of 6812 PCR-verified images categorized into Coccidiosis, Newcastle Disease (NCD), Salmonella, and Healthy from commercial farms in Tanzania was used in this study. Augmentation was used to address the imbalance present in the dataset, with NCD underrepresented (376 images) compared to other classes (>2000 images). Five YOLOv11 detection models were trained, with YOLO11n selected due to its high mean average precision (mAP@0.5 = 0.881). For classification, EfficientNet-B0 was chosen over the EfficientNet-B1 variant because of its high accuracy (99.12% vs. 98.54% for B1). Despite high class imbalance, B0 had higher precision than B1 for the underrepresented NCD class (0.88 for B1 vs. 1.00 for B0). The system achieved an average total inference time of 25.8 milliseconds, demonstrating real-time capabilities. Field testing, expanding datasets across different regions, and incorporating additional diseases is required to further validate and enhance the robustness of the system. Full article

Artificial intelligence (AI) is transforming electrochemical biosensing systems, offering novel solutions for foodborne pathogen detection. This review examines the integration of AI technologies, particularly machine learning and deep learning algorithms, in enhancing sensor design, material optimization, and signal processing for detecting key pathogens such as Escherichia coli, Salmonella, and Staphylococcus aureus. Key advancements include improved sensitivity, multiplexed detection, and adaptability to complex environments. The application of AI to the design of recognition molecules (e.g., enzymes, antibodies, aptamers), as well as to electrochemical parameter tuning and multicomponent signal analysis, is systematically reviewed. Additionally, the convergence of AI with the Internet of Things (IoT) is discussed as a pathway to portable, real-time detection platforms. The review highlights the pivotal role of AI across multiple layers of biosensor development, emphasizing the opportunities and challenges that arise from interdisciplinary integration and the practical deployment of IoT-enabled technologies in electrochemical sensing systems. Despite significant progress, challenges remain in data quality, model generalization, and interpretability. The review concludes by outlining future research directions for building robust, intelligent biosensing systems capable of supporting scalable food safety monitoring. Full article

Antimicrobial resistance (AMR) in environmental reservoirs is an emerging global health concern, particularly in urban settings with inadequate wastewater management. This study aimed to investigate the prevalence and resistance profiles of Salmonella spp. in canal water in Bangkok and assess the distribution of key antibiotic resistance genes (ARGs). Between 2016 and 2019, a total of 1381 water samples were collected from 29 canals. Salmonella spp. were isolated using standard microbiological methods and tested for susceptibility to 13 antibiotics. Polymerase chain reaction (PCR) was used to detect extended-spectrum β-lactamase (ESBL) genes and class 1 integron. Salmonella was found in 89.7% of samples. Among these, 62.1% showed resistance to at least one antimicrobial, and 54.8% were multidrug-resistant (MDR). The highest resistance was observed against streptomycin (41.4%). ESBL genes, predominantly blaCTX-M, were detected in 72.2% of tested isolates, while class 1 integrons were found in 67.8%, indicating a strong potential for gene dissemination. The results highlight urban canals as critical environment reservoirs of AMR Salmonella serovars, posing significant public health risks, particularly where canal water is used for agriculture, household, or recreational purposes. Strengthened environmental surveillance and effective wastewater regulation are urgently needed to mitigate AMR bacteria transmission at the human–environment–animal interface. Full article

Climate change increases microbial contamination risks in food, highlighting the need for real-time biosensors. However, food residues often interfere with detection signals, limiting the direct application. An integrated system of filter-assisted sample preparation (FASP) and an immunoassay-based colorimetric biosensor offers the rapid and simple on-site detection of foodborne pathogens in complex food matrices. The accuracy and stability of biosensor analysis were ensured via filter-assisted preprocessing, which separated food residues from bacteria. The system was applied to various food matrices, including vegetables, meats, and cheese brine, using samples spiked at contamination levels ranging from 10² to 10³ CFU per 25 g, thereby demonstrating broad applicability. Bacterial recovery varied by food matrix, with vegetables showing a 1-log reduction and meats, melon, and cheese brine showing a 2-log reduction relative to the initial inoculum. A detection limit of 10¹ CFU/mL was achieved for Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in the final preprocessed sample solutions. Sample preparation took under 3 min, and detection was completed within 2 h under stationary conditions. This approach enables rapid pathogen detection in various food matrices without the need for special reading devices, contributing to food safety as a real-time, rapid-response food biosensor. Full article

In the case of a notifiable animal disease like salmonellosis, manure is contaminated and must be disinfected. This can be performed using heat measures, chemical disinfectants, or long-term storage. All these measures bring along severe economic, ecological, and logistical problems. The aim of this study was to evaluate lactic acid fermentation (LAF) as an alternative disinfection method. Fermentation was started by adding a carbohydrate source to the manure and creating anaerobic conditions. For testing, cattle manure was enriched with different carbohydrate (CHO) sources and spiked with Salmonella Typhimurium (S. Ty.). The samples were incubated at 10 °C and 21 °C for 111 days (Exp1) and at 21 °C for 50 days (Exp2). The microbial shift was determined using cultural methods and MALDI-TOF. Both the change in pH and Enterococcus spp. were tested as suitable indicators. The results showed the different suitability of the selected CHO for hygienization by LAF. Using squeezed oat as an additive, S. Ty was reduced to below the detection limit under both temperature conditions within 21 days and 14 days. Additional saccharose decreased the reduction time. This study showed that LAF is a valuable alternative for disinfecting cattle manure in the case of bovine salmonellosis. Using this method, both manure and feed residues can be treated in one approach and afterwards be used as fertilizer. Full article

This study developed a technology for restructured meat products (RMPs) from culled cow meat using the bioprotective culture Lactobacillus sakei (SafePro B-2, 10¹¹ CFU/g) and fortification with L-selenomethionine or zinc citrate. Four variants (Control, SafePro B-2, SafePro B-2 + Se, and SafePro B-2 + Zn) were produced under identical processing conditions and assessed for microbiological, physicochemical, textural, colorimetric, antioxidant, histological, mineral, and amino acid properties. Protein content remained high across all samples (up to 18.7%), while moisture increased by up to 1.4% compared to the control. The Zn-enriched sample showed the greatest cohesiveness and resistance to deformation (p < 0.05), with color stability under light exposure improving by up to 12.5%. Despite a reduction in FRAP antioxidant activity (up to 30.8% in buffer extract), the Zn-fortified product exhibited the highest levels of key essential amino acids, including leucine (12.9 mg/g) and lysine (12.6 mg/g). Microbiological analysis confirmed low total aerobic mesophilic counts (≤3.1 log CFU/g), with no detection of Salmonella spp. or Listeria monocytogenes. Histological evaluation revealed denser and more homogeneous protein matrices in fortified variants. Overall, L. sakei-driven bioprotection combined with Se/Zn fortification improved the safety and functional and nutritional characteristics of RMP from low-value beef, supporting sustainable and circular meat production. Full article

Mexican culture offers a great variety of traditional maize-based fermented foods that are beneficial for human health. Atole agrio (sour atole), prepared from blue maize (Zea mays) in the state of Veracruz, has been scarcely studied as a potential functional food. The purpose of this study was to select endogenous potentially probiotic lactic acid bacteria (LAB) from freshly fermented blue maize atole agrio. Samples of spontaneously fermented atole agrio were used for the isolation of LAB on MRS agar. The abilities to tolerate acidic pH, bile salts, and sodium chloride, as well as surface hydrophobicity and aggregation capabilities, were used as criteria for probiotic potential. Selected LAB were identified using MALDI-TOF-MS. Finally, safety-related characterizations, such as hemolytic activity and antibiotic susceptibility, were performed. In the initial stages of fermentation, the presence of fungi, yeasts, coliform organisms, and LAB were detected, and in the final fermentation process, where the blue atole agrio reached a pH of 4, 49 isolates of LAB were obtained. Sixteen isolates showed high tolerance to pH 2, and seven of them showed tolerance to 3% bile salts and 4% sodium chloride. The seven isolates were identified as Pediococcus pentosaceus. Although the seven isolates showed low hydrophobicity to hexadecane and chloroform, they had medium autoaggregation and coaggregation with pathogens. The seven isolates showed notable antibacterial properties against Staphylococcus aureus, Salmonella enterica serovar Typhimurium, Escherichia coli, and Listeria monocytogenes, as well as good amylolytic capacity. All the P. pentosaceus strains were non-hemolytic, sensible to clindamycin and resistant to the other 11 antibiotics tested. Only subtle differences were found among the seven isolates, which can be considered potential candidates for probiotics. The freshly fermented blue maize atole agrio can be considered a functional food containing potentially probiotic LAB and the antioxidant phenolic compounds present in blue maize. Full article

The emergence of multidrug-resistant Salmonella poses a significant threat to global public health and food safety, necessitating the urgent search for new strategies to replace conventional antibiotics. Phages are viruses that can directly target bacteria and have garnered attention in recent years for their development as antibiotic alternatives. In this study, 4458 samples were collected from farms, supermarkets, and human feces, yielding 65 strains of Salmonella, which were serotyped using multiplex PCR. Subsequently, a lytic phage was isolated and identified using the dominant serotype of Salmonella as the host bacterium. We further explored the biological characteristics of this phage through host range, growth properties, and genomic analysis. Finally, we analyzed the potential of the phage to block the cross-host transmission of Salmonella, combining PFGE Salmonella classification, strain sources, and phage lytic phenotypes. The results showed that phage gmqsjt-1 could lyse 69.23% (45/65) of Salmonella, of which 75.56% (34/45) were resistant strains. The optimal multiplicity of infection (MOI) for gmqsjt-1 was 0.01, with a latent period of about 10 min, maintaining high activity within the temperature range of 30 to 60 °C and pH range of 2 to 13. No virulence or resistance genes were detected in the gmqsjt-1 genome, which carries two tail spike proteins (contain FAD binding_2 superfamily, the Tail spike TSP1/Gp66 N-terminal domain, and the Pectin lyase fold) and a holin–lysozyme–spanin lytic system. Phylogenetic classification indicates that phage gmqsjt-1 belongs to a new genus and species of an unnamed family within the class Caudoviricetes. PFGE classification results show a high genetic relationship among human, farm animal, and food source Salmonella, and the comprehensive lytic phenotype reveals that phage gmqsjt-1 can lyse Salmonella with high genetic correlation. These results suggest that this novel lytic Salmonella phage has the potential to inhibit cross-host transmission of Salmonella, making it a promising candidate for developing alternative agents to control Salmonella contamination sources (farms), thereby reducing the risk of human infection with Salmonella through ensuring food system safety. Full article

The widespread prevalence of Salmonella underscores the urgent need for rapid, sensitive, and reliable detection methods to ensure food safety and protection of public health. In this study, we successfully developed an integrated detection system that combines immunomagnetic separation with surface plasmon resonance (SPR) analysis. This system achieved high capture efficiencies, exceeding 96.04% in phosphate-buffered saline and over 91.66% in milk samples artificially spiked with S. Typhimurium at concentrations below 4.2 × 10⁴ CFU/mL. However, direct SPR detection of the isolated S. Typhimurium showed limited sensitivity, with a limit of detection (LOD) of 4.2 × 10⁷ CFU/mL. Incorporating a sandwich assay with antibody-conjugated gold nanoparticles significantly enhanced sensitivity, lowering the LOD by six orders of magnitude to 4.2 × 10¹ CFU/mL. The whole integrated process, integrating immunomagnetic separation with SPR analysis, was completed within 50 min. These results demonstrate that this AuNP-enhanced SPR platform offers both the rapidity and sensitivity essential for effective monitoring of food safety and traceability in Salmonella-related foodborne outbreaks, particularly in products such as milk. Full article

The lack of improved sanitation in rural areas of developing countries, including South Africa, exacerbates open defecation, leading to the significant contamination of water sources by human and animal waste. This study aimed to establish the association of Campylobacter jejuni, Salmonella enterica serovar Typhimurium, Shigella flexneri, and Yersinia enterocolitica in open defecation sites and animal waste with the contamination of water sources in Vhembe District, South Africa. A total of 1032 water samples and 111 faecal samples from the Collins Chabane and Thulamela municipalities were analysed using qPCR. Regression models were used to assess associations, with S. Typhimurium (19–60%) and S. flexneri (11–44%) being the most prevalent bacteria in faecal matter and water, showing detection rates of 4–100% and 5–100%, respectively. Strong associations were found during the wet season between faecal waste and water contamination for S. flexneri (R² = 0.7, p = 0.005) and S. Typhimurium (R² = 0.619, p = 0.091). Urgent measures are needed to address the contamination of rural water sources due to open defecation and livestock waste. Full article

Salmonella is a zoonotic foodborne pathogen that affects poultry health and reaches consumers through the food chain via contaminated products. A cross-sectional study was conducted to isolate and identify Salmonella and to detect antibiotic resistance genes in Salmonella isolates from retail meat shops in Chitwan, Nepal. The antimicrobial susceptibility test was carried out using the Kirby–Bauer disc diffusion method. Antibiotic resistance genes were detected by using multiplex polymerase chain reaction (PCR). A total of 216 samples, chicken meat (108) and water (108), were tested for the presence of Salmonella. Out of the 216 samples tested, 38 samples were positive, giving an overall prevalence of 17.59%. A higher prevalence of Salmonella was found in meat samples, 29.62% (32/108), compared with the water samples, 5.55% (6/108), which was statistically significant (p < 0.05). The antibiogram profile showed maximum resistance to doxycycline (88%), followed by tetracycline (86%), erythromycin (79%), ampicillin + sulbactam (76%), ceftriaxone (22%), levofloxacin (21%), gentamicin (18%), chloramphenicol (13%), and amikacin (15%). The prevalence of the tetB gene and ere(A) gene was 23.68% (9/38) and 18.42% (7/38), respectively, and the association was statistically non-significant (p > 0.05). However, mcr1, catA1, and blaTEM genes were not detected. The study recommends integrated surveillance encompassing human health, food safety, and animal health under the ‘One Health’ approach, highlighting the need for effective strategies involving poultry farms, retail meat shops, and consumers to minimize contamination and reduce the transmission of Salmonella along the food chain from primary production to consumption on a global scale. Full article