Research on the drug resistance mechanism of foodborne pathogens

Impact of Metabolites from Foodborne Pathogens on Cancer

Foodborne pathogens are microorganisms that cause illness through contamination, presenting significant risks to public health and food safety. This review explores the metabolites produced by these pathogens, including toxins and secondary metabolites, and their implications for human health, particularly concerning cancer risk. We examine various pathogens such as Salmonella sp., Campylobacter sp., Escherichia coli, and Listeria monocytogenes, detailing the specific metabolites of concern and their carcinogenic mechanisms. This study discusses analytical techniques for detecting these metabolites, such as chromatography, spectrometry, and immunoassays, along with the challenges associated with their detection. This study covers effective control strategies, including food processing techniques, sanitation practices, regulatory measures, and emerging technologies in pathogen control. This manuscript considers the broader public health implications of pathogen metabolites, highlighting the importance of robust health policies, public awareness, and education. This review identifies research gaps and innovative approaches, recommending advancements in detection methods, preventive strategies, and policy improvements to better manage the risks associated with foodborne pathogens and their metabolites.

Understanding Consumers' Purchase Intention Towards Meat Produced Without Preventive Antibiotic Use

Antibiotics are widely used to prevent healthy animals from getting diseases in livestock industries. Such practice has greatly contributed to the increase in antibiotic-resistant pathogens in animals and in the environment, which poses severe health threats to humans. This study aims to investigate consumers' purchase intention towards meat produced without preventive antibiotic use, and to identify key factors influencing this purchase intention. An online survey of 1123 participants was conducted in China. Descriptive statistical analysis, correlation, and regression analysis were conducted. The results suggested that consumers had a negative attitude towards preventive antibiotic use in food animals and a strong purchase intention towards meat produced without it. The key drivers of this purchase intention included health consciousness, trust in responsible antibiotic use in farming, objective knowledge about antibiotics used in food animals, subjective knowledge about preventive antibiotic use, concerns over antibiotic residues, and attitude towards preventive antibiotic use. These findings can provide deep insights for policymakers and livestock industries who seek to promote responsible antibiotic use and develop effective communication strategies with consumers.

Ocimum basilicum seed-mediated green synthesis of silver nanoparticles: characterization and evaluation of biological properties

Nanoparticles synthesized from green sources have attracted great recognition in the present times, which can be ascribed to their distinctive attributes and diversified applicability. Therefore, the present study employed Ocimum basilicum seed extract to synthesize silver nanoparticles. UV-vis spectrophotometry revealed strenuous peaks for different concentrations of silver nanoparticles ranging between 400 and 430 nm. The average crystal size calculated using X-ray diffraction analysis was 6.7 nm. Energy-dispersive X-ray analysis clearly displayed the presence of silver ions in the elemental structure of the synthesized nanoparticles. The morphology of synthesized nanoparticles revealed by scanning electron microscopy was documented in terms of spherical shape surrounded by an organic layer and nanoparticle size was estimated to be in between 10 and 80 nm. The nanoparticles exhibited substantial antibacterial activity against 46 foodborne bacterial isolates and 15 clinical isolates of Klebsiella pneumoniae, with the largest inhibition zones measuring 24 and 13 mm, respectively. Minimum inhibitory concentration values ranged between 500 and 800 µl/ml for various isolates. The antibacterial effect of all antibiotics revealed considerable enhancement when combined with nanoparticles. The calculated fractional inhibitory concentration index values were < 1 validating excellent synergism between nanoparticles and all antibiotics except ciprofloxacin against the majority of bacterial isolates. Interestingly, the biogenic nanoparticles showed significant antioxidant potential with IC50 value of 165 µg/ml as well as anti-inflammatory activity with an IC50 value of 82 µg/ml. Conclusively, the seed extract of Ocimum basilicum can be prospected for the development of antibacterial silver nanoparticles against pathogenic bacteria.

Ultrasensitive Electrochemical Detection of Salmonella typhimurium in Food Matrices Using Surface-Modified Bacterial Cellulose with Immobilized Phage Particles

The rapid and sensitive detection of Salmonella typhimurium in food matrices is crucial for ensuring food safety. This study presents the development of an ultrasensitive electrochemical biosensor using surface-modified bacterial cellulose (BC) integrated with polypyrrole (Ppy) and reduced graphene oxide (RGO), further functionalized with immobilized S. typhimurium-specific phage particles. The BC substrate, with its ultra-fibrous and porous structure, was modified through in situ oxidative polymerization of Ppy and RGO, resulting in a highly conductive and flexible biointerface. The immobilization of phages onto this composite was facilitated by electrostatic interactions between the polycationic Ppy and the negatively charged phage capsid heads, optimizing phage orientation and enhancing bacterial capture efficiency. Morphological and chemical characterization confirmed the successful fabrication and phage immobilization. The biosensor demonstrated a detection limit of 1 CFU/mL for S. typhimurium in phosphate-buffered saline (PBS), with a linear detection range spanning 100 to 107 CFU/mL. In real samples, the sensor achieved detection limits of 5 CFU/mL in milk and 3 CFU/mL in chicken, with a linear detection range spanning 100 to 106 CFU/mL, maintaining high accuracy and reproducibility. The biosensor also effectively discriminated between live and dead bacterial cells, demonstrating its potential in real-world food safety applications. The biosensor performed excellently over a wide pH range (4-10) and remained stable for up to six weeks. Overall, the developed BC/Ppy/RGO-phage biosensor offers a promising tool for the rapid, sensitive, and selective detection of S. typhimurium, with robust performance across different food matrices.

Use of Metallic Nanoparticles Against Eimeria-the Coccidiosis-Causing Agents: A Comprehensive Review

Coccidiosis is a protozoan disease caused by Eimeria species and is a major threat to the poultry industry. Different anti-coccidial drugs (diclazuril, amprolium, halofuginone, ionophores, sulphaquinoxaline, clopidol, and ethopabate) and vaccines have been used for their control. Still, due to the development of resistance, their efficacy has been limited. It is continuously damaging the economy of the poultry industry because under its control, almost $14 billion is spent, globally. Recent research has been introducing better and more effective control of coccidiosis by using metallic and metallic oxide nanoparticles. Zinc, zinc oxide, copper, copper oxide, silver, iron, and iron oxide are commonly used because of their drug delivery mechanism. These nanoparticles combined with other drugs enhance the effect of these drugs and give their better results. Moreover, by using nanotechnology, the resistance issue is also solved because by using several mechanisms at a time, protozoa cannot evolve and thus resistance cannot develop. Green nanotechnology has been giving better results due to its less toxic effects. Utilization of metallic and metallic oxide nanoparticles may present a new, profitable, and economical method of controlling chicken coccidiosis, thus by changing established treatment approaches and improving the health and production of chickens. Thus, the objective of this review is to discuss about economic burden of avian coccidiosis, zinc, zinc oxide, iron, iron oxide, copper, copper oxide, silver nanoparticles use in the treatment of coccidiosis, their benefits, and toxicity.

A CRISPR/Cas12a-powered gold/nickel foam surface-enhanced Raman spectroscopy biosensor for nucleic acid specific detection in foods

Food is a necessary source of energy, but it also serves as a pathway for transmitting infectious pathogens, making food safety a matter of great concern. Rapid, accurate, and specific detection methods for foodborne viruses are crucial. Surface-Enhanced Raman Scattering (SERS), due to its superior sensitivity and characteristic fingerprint spectra, holds enormous potential. However, due to the limitations of SERS, it requires specific conditions to achieve specificity. In order to enhance the specificity and accuracy of nucleic acid detection based on SERS, we have developed a CRISPR-Cas12a-mediated SERS technique to identify target DNA, harnessing the targeting recognition capability of CRISPR-Cas12a and ultra-sensitive SERS tags and successfully addressing SERS' lack of specific detection capability. This system includes a gold/nickel foam substrate (Au-NFs) and a reporter (ssDNA-ROX). The phenomenon of colloidal gold/silver nano-aggregation due to magnesium ions, which is commonly encountered in CRISPR-SERS, was simultaneously solved using AuNFs. The qualitative and quantitative analysis of target DNA in drinking water was performed by monitoring the intensity change of ROX Raman reporter molecules. The results showed that the sensor detected DNA within 30 min and the limit of detection (LOD) was 8.23 fM. This is expected to become one of the alternative methods for nucleic acid detection for its rapid detection and high specificity.

A Nomogram for Predicting the Effectiveness of Consultations on Multi-Drug Resistant Infections: An Exploration for Clinical Pharmacy Services

Purpose

The increasing multi-drug resistance (MDR) is a serious threat to human health. The appropriate use of antibiotics can control the progression of MDR and clinical pharmacists play an important role in the rational use of antibiotics. There are many factors that influence the effectiveness of multi-drug resistant organisms (MDRO) infection consultations. The study aimed to establish a model to predict the outcome of consultation and explore ways to improve clinical pharmacy services.

Patients and methods

Patients diagnosed with MDRO infection and consulted by clinical pharmacists were included. Univariate analysis and multivariate logistic regression analysis were used to identify independent risk factors for MDRO infection consultation effectiveness, and then a nomogram was constructed and validated.

Results

198 patients were finally included. The number of underlying diseases (OR=1.720, 95% CI: 1.260-2.348), whether surgery was performed prior to infection (OR=8.853, 95% CI: 2.668-29.373), ALB level (OR=0.885, 95% CI: 0.805~0.974), pharmacist title (OR=3.463, 95% CI: 1.277~9.396) and whether the recommendation was taken up (OR=0.117, 95% CI: 0.030~0.462) were identified as independent influences on the effectiveness of the consultation. The nomogram prediction model was successfully constructed and the AUC of the training set and the verification set were 0.849 (95% CI: 0.780-0.917) and 0.761 (95% CI: 0.616-0.907) respectively. The calibration curves exhibited good overlap between the data predicted by the model and the actual data.

Conclusion

A nomogram model was developed to predict the risk of consultation failure and was shown to be good accuracy and good prediction efficiency, which can provide proactive interventions to improve outcomes for potentially treatment ineffective patients.

Antimicrobial resistance in food-borne pathogens at the human-animal interface: Results from a large surveillance study in India

Background

The burden of foodborne diseases and antimicrobial resistance carried by key foodborne pathogens in India is unknown due to a lack of an integrated surveillance system at the human-animal interface.

Methods

We present data from the WHO-AGISAR (Advisory Group on Integrated Surveillance of Antimicrobial Resistance), India project. Concurrent human and animal sampling was done across a large area across north India. Community-acquired diarrhea cases (n = 1968) of all age groups were included. Cross-sectional sampling of stool/ intestinal contents (n = 487) and meat samples (n = 419) from food-producing animals was done at farms, retail shops, and slaughterhouses. Pathogens were cultured and identified, and antimicrobial susceptibility was performed.

Results

Over 80% of diarrhoeal samples were obtained from moderate to severe diarrhea patients, which yielded EAEC (5%), ETEC (4.84%), EPEC (4.32%), and Campylobacter spp. (2%). A high carriage of EPEC (32.11%) and Campylobacter spp. (24.72%) was noted in food animals, but the prevalence of ETEC (2%) and EAEC (1%) was low. Atypical EPEC (aEPEC, 84.52%, p ≤0.0001) were predominant and caused milder diarrhea. All EPEC from animal/poultry were aEPEC. Overall, a very high level of resistance was observed, and the MDR rate ranged from 29.2% in Campylobacter spp., 53.6% in EPEC, and 59.8% in ETEC. Resistance to piperacillin-tazobactam, cefepime, ceftriaxone, and co-trimoxazole was significantly higher in human strains. In contrast, resistance to ciprofloxacin, aminoglycosides, and tetracycline was higher in animal strains, reflecting the corresponding usage in human and animal sectors. ESBL production was commoner in animal isolates than in humans, indicating high use of third-generation cephalosporins in the animal sector. C. hyointestinalis is an emerging zoonotic pathogen, first time reported from India.

Conclusion

In one of the most extensive studies from India, a high burden of key foodborne pathogens with MDR and ESBL phenotypes was found in livestock, poultry, and retail meat.

Simultaneous Dual-Gene Test of Methicillin-Resistant Staphylococcus Aureus using an Argonaute-Centered Portable and Visual Biosensor

The development of novel method for drug-resistant bacteria detection is imperative. A simultaneous dual-gene Test of methicillin-resistant Staphylococcus aureus (MRSA) is developed using an Argonaute-centered portable biosensor (STAR). This is the first report concerning Argonaute-based pathogenic bacteria detection. Simply, the species-specific mecA and nuc gene are isothermally amplified using loop-mediated isothermal amplification (LAMP) technique, followed by Argonaute-based detection enabled by its programmable, guided, sequence-specific recognition and cleavage. With the strategy, the targeted nucleic acid signals gene are dexterously converted into fluorescent signals. STAR is capable of detecting the nuc gene and mecA gene simultaneously in a single reaction. The limit of detection is 10 CFU/mL with a dynamic range from 10 to 107 CFU/mL. The sample-to-result time is <65 min. This method is successfully adapted to detect clinical samples, contaminated foods, and MRSA-infected animals. This work broadens the reach of Argonaute-based biosensing and presents a novel bacterial point-of-need (PON) detection platform.

Effects of UV/H2O2 Degradation on the Physicochemical and Antibacterial Properties of Fucoidan

The applications of fucoidan in the food industry were limited due to its high molecular weight and low solubility. Moderate degradation was required to depolymerize fucoidan. A few studies have reported that fucoidan has potential antibacterial activity, but its antibacterial mechanism needs further investigation. In this study, the degraded fucoidans were obtained after ultraviolet/hydrogen peroxide treatment (UV/H2O2) at different times. Their physicochemical properties and antibacterial activities against Staphylococcus aureus and Escherichia coli were investigated. The results showed that the average molecular weights of degraded fucoidans were significantly decreased (up to 22.04 times). They were mainly composed of fucose, galactose, and some glucuronic acid. Fucoidan degraded for 90 min (DFuc-90) showed the strongest antibacterial activities against Staphylococcus aureus and Escherichia coli, with inhibition zones of 27.70 + 0.84 mm and 9.25 + 0.61 mm, respectively. The minimum inhibitory concentrations (MIC) were 8 mg/mL and 4 mg/mL, respectively. DFuc-90 could inhibit the bacteria by damaging the cell wall, accumulating intracellular reactive oxygen species, reducing adenosine triphosphate synthesis, and inhibiting bacterial metabolic activity. Therefore, UV/H2O2 treatment could effectively degrade fucoidan and enhance its antibacterial activity.

Bacteriophages in nature: recent advances in research tools and diverse environmental and biotechnological applications

Bacteriophages infect and replicate within bacteria and play a key role in the environment, particularly in microbial ecosystems and bacterial population dynamics. The increasing recognition of their significance stems from their wide array of environmental and biotechnological uses, which encompass the mounting issue of antimicrobial resistance (AMR). Beyond their therapeutic potential in combating antibiotic-resistant infections, bacteriophages also find vast applications such as water quality monitoring, bioremediation, and nutrient cycling within environmental sciences. Researchers are actively involved in isolating and characterizing bacteriophages from different natural sources to explore their applications. Gaining insights into key aspects such as the life cycle of bacteriophages, their host range, immune interactions, and physical stability is vital to enhance their application potential. The establishment of diverse phage libraries has become indispensable to facilitate their wide-ranging uses. Consequently, numerous protocols, ranging from traditional to cutting-edge techniques, have been developed for the isolation, detection, purification, and characterization of bacteriophages from diverse environmental sources. This review offers an exploration of tools, delves into the methods of isolation, characterization, and the extensive environmental applications of bacteriophages, particularly in areas like water quality assessment, the food sector, therapeutic interventions, and the phage therapy in various infections and diseases.

Optical nanosensors based on noble metal nanoclusters for detecting food contaminants: A review

Food contaminants present a significant threat to public health. In response to escalating global concerns regarding food safety, there is a growing demand for straightforward, rapid, and sensitive detection technologies. Noble metal nanoclusters (NMNCs) have garnered considerable attention due to their superior attributes compared to other optical materials. These attributes include high catalytic activity, excellent biocompatibility, and outstanding photoluminescence properties. These features render NMNCs promising candidates for crafting nanosensors for food contaminant detection, offering the potential for the development of uncomplicated, swift, sensitive, user-friendly, and cost-effective detection approaches. This review investigates optical nanosensors based on NMNCs, including the synthesis methodologies of NMNCs, sensing strategies, and their applications in detecting food contaminants. Furthermore, it involves a comparative assessment of the applications of NMNCs in optical sensing and their performance. Ultimately, this paper imparts fresh perspectives on the forthcoming challenges. Hitherto, optical (particularly fluorescent) nanosensors founded on NMNCs have demonstrated exceptional sensing capabilities in the realm of food contaminant detection. To enhance sensing performance, future research should prioritize atomically precise NMNCs synthesis, augmentation of catalytic activity and optical properties, development of high-throughput and multimode sensing, integration of NMNCs with microfluidic devices, and the optimization of NMNCs storage, shelf life, and transportation conditions.

Foodborne Pathogen Dynamics in Meat and Meat Analogues Analysed Using Traditional Microbiology and Metagenomic Sequencing

Meat analogues play an increasing role in meeting global nutritional needs. However, while it is well known that meat possesses inherent characteristics that create favourable conditions for the growth of various pathogenic bacteria, much less is known about meat analogues. This study aimed to compare the growth and survival of Escherichia coli HEHA16, Listeria monocytogenes, Salmonella enterica Typhi, Cronobacter sakazakii, and a cocktail of these bacteria in sterile juices from minced chicken, pig, and beef, as well as pea-based and soy-based minced meat. Traditional microbiology and next-generation sequencing of those metagenomes were employed to analyse the pathogen variability, abundance, and survival after an incubation period. Our findings show that all the meat juices provided favourable conditions for the growth and proliferation of the studied bacteria, with the exception of E. coli HEHA16, which showed lower survival rates in the chicken matrix. Meat analogue juice mainly supported L. monocytogenes survival, with C. sakazakii survival supported to a lesser extent. A correlation was observed between the traditional culturing and metagenomic analysis results, suggesting that further work is needed to compare these technologies in foodborne setups. Our results indicate that plant-based meats could serve as vectors for the transmission of certain, but likely not all, foodborne pathogens, using two accurate detection methods. This warrants the need for additional research to better understand and characterise their safety implications, including their potential association with additional pathogens.

A review on synthesis and antibacterial potential of bio-selenium nanoparticles in the food industry

Effective control of foodborne pathogen contamination is a significant challenge to the food industry, but the development of new antibacterial nanotechnologies offers new opportunities. Notably, selenium nanoparticles have been extensively studied and successfully applied in various food fields. Selenium nanoparticles act as food antibacterial agents with a number of benefits, including selenium as an essential trace element in food, prevention of drug resistance induction in foodborne pathogens, and improvement of shelf life and food storage conditions. Compared to physical and chemical methods, biogenic selenium nanoparticles (Bio-SeNPs) are safer and more multifunctional due to the bioactive molecules in Bio-SeNPs. This review includes a summarization of (1) biosynthesized of Bio-SeNPs from different sources (plant extracts, fungi and bacteria) and their antibacterial activity against various foodborne bacteria; (2) the antibacterial mechanisms of Bio-SeNPs, including penetration of cell wall, damage to cell membrane and contents leakage, inhibition of biofilm formation, and induction of oxidative stress; (3) the potential antibacterial applications of Bio-SeNPs as food packaging materials, food additives and fertilizers/feeds for crops and animals in the food industry; and (4) the cytotoxicity and animal toxicity of Bio-SeNPs. The related knowledge contributes to enhancing our understanding of Bio-SeNP applications and makes a valuable contribution to ensuring food safety.

Antibiotic resistance mechanism and diagnosis of common foodborne pathogens based on genotypic and phenotypic biomarkers

The emergence of antibiotic-resistant bacteria due to the overuse or inappropriate use of antibiotics has become a significant public health concern. The agri-food chain, which serves as a vital link between the environment, food, and human, contributes to the large-scale dissemination of antibiotic resistance, posing a concern to both food safety and human health. Identification and evaluation of antibiotic resistance of foodborne bacteria is a crucial priority to avoid antibiotic abuse and ensure food safety. However, the conventional approach for detecting antibiotic resistance heavily relies on culture-based methods, which are laborious and time-consuming. Therefore, there is an urgent need to develop accurate and rapid tools for diagnosing antibiotic resistance in foodborne pathogens. This review aims to provide an overview of the mechanisms of antibiotic resistance at both phenotypic and genetic levels, with a focus on identifying potential biomarkers for diagnosing antibiotic resistance in foodborne pathogens. Furthermore, an overview of advances in the strategies based on the potential biomarkers (antibiotic resistance genes, antibiotic resistance-associated mutations, antibiotic resistance phenotypes) for antibiotic resistance analysis of foodborne pathogens is systematically exhibited. This work aims to provide guidance for the advancement of efficient and accurate diagnostic techniques for antibiotic resistance analysis in the food industry.

Portable dual-mode biosensor based on smartphone and glucometer for on-site sensitive detection of Listeria monocytogenes

Contamination of Listeria monocytogenes (L. monocytogenes) in the environment and food can pose a serious threat to human health, and there is an urgent need to establish sensitive on-situ detection methods to mitigate its hazards. In this study, we have developed a field assay that combines magnetic separation technology with antibody-labeled ZIF-8 encapsulating glucose oxidase (GOD@ZIF-8@Ab) to capture and specifically identify L. monocytogenes while GOD catalyzes glucose catabolism to produce signal changes in glucometers. On the other side, horseradish peroxidase (HRP) and 3,3',5,5'-tetramethylbenzidine (TMB) were added to recombined with the H₂O₂ generated by the catalyst to form a colorimetric reaction system that changes from colorless to blue. The smartphone software was used for RGB analysis to complete the on-site colorimetric detection of L. monocytogenes. This dual-mode biosensor showed good detection performance for the on-site application of L. monocytogenes in lake water and juice samples, both with a limit of detection up to 10¹ CFU/mL and a good linear range of 10¹-10⁶ CFU/mL. Therefore, this dual-mode on-site detection biosensor has a promising application for the early screening of L. monocytogenes in environmental and food samples.

Antibiotic Resistance in Selected Emerging Bacterial Foodborne Pathogens-An Issue of Concern?

Antibiotic resistance (AR) and multidrug resistance (MDR) have been confirmed for all major foodborne pathogens: Campylobacter spp., Salmonella spp., Escherichia coli and Listeria monocytogenes. Of great concern to scientists and physicians are also reports of antibiotic-resistant emerging food pathogens-microorganisms that have not previously been linked to food contamination or were considered epidemiologically insignificant. Since the properties of foodborne pathogens are not always sufficiently recognized, the consequences of the infections are often not easily predictable, and the control of their activity is difficult. The bacteria most commonly identified as emerging foodborne pathogens include Aliarcobacter spp., Aeromonas spp., Cronobacter spp., Vibrio spp., Clostridioides difficile, Escherichia coli, Mycobacterium paratuberculosis, Salmonella enterica, Streptocccus suis, Campylobacter jejuni, Helicobacter pylori, Listeria monocytogenes and Yersinia enterocolitica. The results of our analysis confirm antibiotic resistance and multidrug resistance among the mentioned species. Among the antibiotics whose effectiveness is steadily declining due to expanding resistance among bacteria isolated from food are β-lactams, sulfonamides, tetracyclines and fluoroquinolones. Continuous and thorough monitoring of strains isolated from food is necessary to characterize the existing mechanisms of resistance. In our opinion, this review shows the scale of the problem of microbes related to health, which should not be underestimated.

An Overview of the Public Health Challenges in Diagnosing and Controlling Human Foodborne Pathogens

Pathogens found in food are believed to be the leading cause of foodborne illnesses; and they are considered a serious problem with global ramifications. During the last few decades, a lot of attention has been paid to determining the microorganisms that cause foodborne illnesses and developing new methods to identify them. Foodborne pathogen identification technologies have evolved rapidly over the last few decades, with the newer technologies focusing on immunoassays, genome-wide approaches, biosensors, and mass spectrometry as the primary methods of identification. Bacteriophages (phages), probiotics and prebiotics were known to have the ability to combat bacterial diseases since the turn of the 20th century. A primary focus of phage use was the development of medical therapies; however, its use quickly expanded to other applications in biotechnology and industry. A similar argument can be made with regards to the food safety industry, as diseases directly endanger the health of customers. Recently, a lot of attention has been paid to bacteriophages, probiotics and prebiotics most likely due to the exhaustion of traditional antibiotics. Reviewing a variety of current quick identification techniques is the purpose of this study. Using these techniques, we are able to quickly identify foodborne pathogenic bacteria, which forms the basis for future research advances. A review of recent studies on the use of phages, probiotics and prebiotics as a means of combating significant foodborne diseases is also presented. Furthermore, we discussed the advantages of using phages as well as the challenges they face, especially given their prevalent application in food safety.

Integrating Network Pharmacology Approaches to Decipher the Multi-Target Pharmacological Mechanism of Microbial Biosurfactants as Novel Green Antimicrobials against Listeriosis

Listeria monocytogenes (L. monocytogenes) is a serious food-borne pathogen that can cause listeriosis, an illness caused by eating food contaminated with this pathogen. Currently, the treatment or prevention of listeriosis is a global challenge due to the resistance of bacteria against multiple commonly used antibiotics, thus necessitating the development of novel green antimicrobials. Scientists are increasingly interested in microbial surfactants, commonly known as "biosurfactants", due to their antimicrobial properties and eco-friendly nature, which make them an ideal candidate to combat a variety of bacterial infections. Therefore, the present study was designed to use a network pharmacology approach to uncover the active biosurfactants and their potential targets, as well as the signaling pathway(s) involved in listeriosis treatment. In the framework of this study, 15 biosurfactants were screened out for subsequent studies. Among 546 putative targets of biosurfactants and 244 targets of disease, 37 targets were identified as potential targets for treatment of L. monocytogenes infection, and these 37 targets were significantly enriched in a Gene Ontology (GO) analysis, which aims to identify those biological processes, cellular locations, and molecular functions that are impacted in the condition studied. The obtained results revealed several important biological processes, such as positive regulation of MAP kinase activity, protein kinase B signaling, ERK1 and ERK2 cascade, ERBB signaling pathway, positive regulation of protein serine/threonine kinase activity, and regulation of caveolin-mediated endocytosis. Several important KEGG pathways, such as the ERBBB signaling pathway, TH17 cell differentiation, HIF-1 signaling pathway, Yersinia infection, Shigellosis, and C-type lectin receptor signaling pathways, were identified. The protein-protein interaction analysis yielded 10 core targets (IL2, MAPK1, EGFR, PTPRC, TNF, ITGB1, IL1B, ERBB2, SRC, and mTOR). Molecular docking was used in the latter part of the study to verify the effectiveness of the active biosurfactants against the potential targets. Lastly, we found that a few highly active biosurfactants, namely lichenysin, iturin, surfactin, rhamnolipid, subtilisin, and polymyxin, had high binding affinities towards IL2, MAPK1, EGFR, PTPRC, TNF, ITGB1, IL1B, ERBB2, SRC, and mTOR, which may act as potential therapeutic targets for listeriosis. Overall, based on the integrated network pharmacology and docking analysis, we found that biosurfactants possess promising anti-listeriosis properties and explored the pharmacological mechanisms behind their effect, laying the groundwork for further research and development.

Multidrug-Resistant Biofilms (MDR): Main Mechanisms of Tolerance and Resistance in the Food Supply Chain

Biofilms are mono- or multispecies microbial communities enclosed in an extracellular matrix (EPS). They have high potential for dissemination and are difficult to remove. In addition, biofilms formed by multidrug-resistant strains (MDRs) are even more aggravated if we consider antimicrobial resistance (AMR) as an important public health issue. Quorum sensing (QS) and horizontal gene transfer (HGT) are mechanisms that significantly contribute to the recalcitrance (resistance and tolerance) of biofilms, making them more robust and resistant to conventional sanitation methods. These mechanisms coordinate different strategies involved in AMR, such as activation of a quiescent state of the cells, moderate increase in the expression of the efflux pump, decrease in the membrane potential, antimicrobial inactivation, and modification of the antimicrobial target and the architecture of the EPS matrix itself. There are few studies investigating the impact of the use of inhibitors on the mechanisms of recalcitrance and its impact on the microbiome. Therefore, more studies to elucidate the effect and applications of these methods in the food production chain and the possible combination with antimicrobials to establish new strategies to control MDR biofilms are needed.

Advances in magnetic nanoparticles for the separation of foodborne pathogens: Recognition, separation strategy, and application

Foodborne pathogens contamination is one of the main sources of food safety problems. Although the existing detection methods have been developed for a long time, the complexity of food samples is still the main factor affecting the detection time and sensitivity, and the rapid separation and enrichment of pathogens is still an objective to be studied. Magnetic separation strategy based on magnetic nanoparticles (MNPs) is considered to be an effective tool for rapid separation and enrichment of foodborne pathogens in food. Therefore, this study comprehensively reviews the development of MNPs in the separation of foodborne pathogens over the past decade. First, various biorecognition reagents for identification of foodborne pathogens and their modifications on the surface of MNPs are introduced. Then, the factors affecting the separation of foodborne pathogens, including the size of MNPs, modification methods, separation strategies and separation forms are discussed. Finally, the application of MNPs in integrated detection methods is reviewed. Moreover, current challenges and prospects of MNPs for the analysis of foodborne pathogens are discussed. Further research should focus on the design of multifunctional MNPs, the processing of large-scale samples, the simultaneous analysis of multiple targets, and the development of all-in-one small analytical device with separation and detection.

Modification of polyacrylonitrile-derived carbon nanofibers and bacteriophages on screen-printed electrodes: A portable electrochemical biosensor for rapid detection of Escherichia coli

A facile method was developed for fabricating a disposable phage-based electrochemical biosensor for the detection of Escherichia coli. Bare screen-printed electrodes (SPEs) were modified using a two-step drop-casting method, in which polyacrylonitrile-derived electrospun carbon nanofibers (CNFs) were deposited, followed by E. coli bacteriophage immobilization. The deposition of CNFs increased the surface area for bacteriophage immobilization while maintaining a conductive link for ferro/ferricyanide redox transitions. Cyclic voltammetry and electrochemical impedance spectroscopy confirmed that the CNF modification increased the electron-transfer rate, whereas bacteriophages and E. coli blocked electron transfer at the electrode. The biosensor achieved a response within 10 min and a linear response in the E. coli concentration range of 10²-10⁶ CFU/mL. A limit of detection (LOD) of 36 CFU/mL in phosphate-buffered saline was achieved, which is the lowest LOD reported thus far for phage-based disposable SPE sensors. The biosensor exhibited recovery rates between 106 % and 119 % for E. coli detection in apple juice. The proposed fabrication method allowed electrodes to be obtained from different production batches with remarkable consistency and reproducibility, and they remained stable at room temperature for one month. Thus, a phage-based disposable SPE that can be used for bacterial detection was developed for the first time.

Application of sonodynamic technology and sonosensitizers in food sterilization: a review of developments, trends and challenges

Food safety and food waste have always been hot topics of discussion in recent years. However, the infection of human pathogenic bacteria and the waste of food resources caused by microbial-contaminated food remains common. Although traditional sterilization technology has been very mature, it causes changes in food flavor and excessive energy consumption to a certain extent. Moreover, the widespread bacterial resistance has also sounded a warning for researchers and finding a new alternative to antibiotics is urgently needed. The application of sonodynamic sterilization technology in medical treatment has aroused the interest of researchers. It provides ideas for new food sterilization technology. As a new non-thermal sterilization technology, sonodynamic sterilization technology has strong penetration, safety, less residue and by-products, and will less change the quality of the food itself. Therefore, sonodynamic sterilization technology has great potential applied in food sterilization technology. This review describes the concept of sonodynamic sterilization technology, the sterilization mechanism of sonodynamic sterilization and the inactivation mechanism of various pathogens, the classification and application of sonosensitizers, and the ultrasonic technology in sonodynamic sterilization in the application over the recent years. It provides a scientific reference for the application of sonodynamic sterilization technology in the field of food sterilization.

Research progress on detection techniques for point-of-care testing of foodborne pathogens

The global burden of foodborne disease is enormous and foodborne pathogens are the leading cause of human illnesses. The detection of foodborne pathogenic bacteria has become a research hotspot in recent years. Rapid detection methods based on immunoassay, molecular biology, microfluidic chip, metabolism, biosensor, and mass spectrometry have developed rapidly and become the main methods for the detection of foodborne pathogens. This study reviewed a variety of rapid detection methods in recent years. The research advances are introduced based on the above technical methods for the rapid detection of foodborne pathogenic bacteria. The study also discusses the limitations of existing methods and their advantages and future development direction, to form an overall understanding of the detection methods, and for point-of-care testing (POCT) applications to accurately and rapidly diagnose and control diseases.

Antimicrobial Properties of Chilean Native Plants: Future Aspects in Their Application in the Food Industry

Food contamination with microorganisms is responsible for food spoilage, deterioration and change of organoleptic properties of foods. Besides, the growth of pathogenic microorganisms can provoke serious health problems if food is consumed. Innovative packaging, such as active packaging, is increasing rapidly in the food industry, especially in applying antimicrobials into delivery systems, such as sachets. Chile is a relevant hotspot for biodiversity conservation and a source of unique bio-resources with antimicrobial potential. In this review, fifteen native plants with antimicrobial properties are described. Their antimicrobial effects include an effect against human pathogens. Considering the emergence of antimicrobial resistance, searching for new antimicrobials to design new strategies for food pathogen control is necessary. Chilean flora is a promising source of antimicrobials to be used in active packaging. However, further studies are required to advance from laboratory tests of their antimicrobial effects to their possible effects and uses in active films.

Characterization of Erysipelothrix rhusiopathiae Isolates from Diseased Pigs in 15 Chinese Provinces from 2012 to 2018

Erysipelothrix rhusiopathiae can cause erysipelas in animals and erysipeloid in humans. Since its recurrence in 2012, swine erysipelas has caused serious losses within the pig industry in China. The aim of this study was to perform multilocus sequence typing and understand the virulence and antimicrobial susceptibility of E. rhusiopathiae isolates in China. Multilocus sequence typing (MLST) of a total of 120 strains was performed, and as a result, three different sequence types were identified, of which ST48 was the main one. Five isolates of each MLST type were randomly selected to be used to challenge mice. ST48 was associated with a higher virulence. Antimicrobial susceptibility was tested using a microdilution technique and, to analyze the resistance mechanism, six strains were selected for genome sequencing. A comparison of the six genomes indicated the presence of a suspected macrolide resistance gene, namely, Erm(A)-like, in erythromycin-resistant strains, which increased the minimum inhibitory concentration (MIC) of erythromycin against E. coli C600 at least four-fold. In addition, three mutations (gyrA86T-I, gyrA90D-N, and parC81S-I) were observed in the quinolone resistance-determining regions (QRDRs) of gyrA and parC in quinolone-resistant strains. After the gyrA gene with the 86T-I mutation or the parC gene with the 81S-I mutation was transfected into E. coli C600, the MIC of enrofloxacin against this strain increased at least two-fold. Our findings provide a theoretical basis for developing antibacterial drugs and may contribute to the clinical prevention and control of E. rhusiopathiae.