Antibiotic Use in Livestock and Residues in Food-A Public Health Threat: A Review

Molecular characterization of emerging multi-drug resistant Clostridium perfringens isolated from pork production chains in Korea

Clostridium perfringens is a common cause of foodborne illnesses and is involved in human and animal gastrointestinal diseases. Surveillance of C. perfringens in the pork production chain is crucial to manage the risk of pathogen transmission. This study aimed to investigate the prevalence, antimicrobial resistance profile, and genomic characteristics of C. perfringens in pork production chains in Korea. The overall prevalence of C. perfringens was 23.6% (330/1397), with 48.8 (178/365), 16.6 (138/832), and 7.0% (14/200) in pig farms, slaughterhouses, and retail markets, respectively. Toxinotyping revealed 98.9% type A and 1.1% type C isolates. Among them, 29.1% carried the beta-2 toxin gene. Antimicrobial susceptibility tests identified 20 multi-drug resistant isolates, with the highest resistance against tetracycline (65.1%). Whole-genome sequencing further revealed 17 antimicrobial resistance and 12 virulence genes. Subsequent phylogenetic analysis identified three clonal clusters, two of which revealed a clonal relationship with human clinical isolates reported in China. The ST408 isolate from the retail pork meat, IJCP45, harboured the optrA gene in a plasmid and was identical to known optrA-carrying plasmids in C. perfringens from livestock in China, suggesting the introduction and dissemination of optrA by the transmission of a specific plasmid in east Asian countries. To our knowledge, this is the first comprehensive study of C. perfringens in the pork meat production system as an "One Health" approach. The study findings provide baseline data for the distribution and genetic characteristics of pig-associated C. perfringens in Korea and indicate the zoonotic transmission potential of C. perfringens from pigs to humans.

Thermal stability enhancement of erythromycin esterase C from Enterobacter hormaechei through a combinatorial greedy accumulated strategy

The presence of macrolides in food and the environment poses a substantial threat to the sustainable development of natural ecosystems and presents risks to human health. Previous research has demonstrated that microbial esterases can degrade erythromycin (Ery), roxithromycin (Rox), and clarithromycin (Clr), rendering them candidates for bioremediation of macrolide residues. However, the efficacy of esterases is limited by insufficient thermal stability, restricting their widespread application. To address this challenge, this study employed a combinatorial strategy integrating computational molecular dynamics (MD) simulations, server-assisted virtual mutation prediction, and a greedy algorithm for protein engineering to enhance the thermal stability of esterase C from Enterobacter hormaechei (Ehno-EreC). After four rounds of screening, we successfully obtained a four-point mutant, M4 (D245P/S141A/D154I/T292W), which exhibited significantly improved thermal stability compared to the wild-type enzyme. Notably, the M4 mutant not only extended the enzyme's half-life at 40 °C from 7 to 1095 min, but also increased its degradation activity against Ery, Rox, and Clr. Structural analyses revealed enhanced rigidity in the loop between the major and minor lobes and the strengthened hydrophobic interactions post-mutation, contributing to the enzyme's structural stability. This finding was consistent with the observed reduction in correlated and anti-correlated motions in the MD trajectory.

The future of phage therapy in the USA

Fueled by the increasing abundance of antibiotic-resistant pathogens, there has been a resurrection in the use of bacterial viruses (bacteriophages or 'phage') for therapeutic applications. Phage therapy was used in the early 20th century to limited success, which we attribute to its haphazard employment. To avoid repeating the mistakes of the past, this Opinion first evaluates the historical reasons for the failure of phage therapy, analyzes the current state of the field, and ultimately makes recommendations for how to proceed with contemporary phage therapy. Despite many advances in phage biology, crucial gaps in our knowledge persist. Our recommendations require physicians, scientists, and public-policy leaders to cooperate to bridge the outstanding gaps around phage therapy to develop phage into a useful therapeutic tool.

Listeria monocytogenes and Listeriosis: The Global Enigma

Listeria monocytogenes is an intracellular, Gram-positive, non-spore-forming, non-encapsulated, facultative anaerobic, rod-shaped, and psychrotrophic food-borne pathogen that causes the infection, listeriosis, thus it attracts great attention following listeriosis outbreaks, which are often associated with high mortality rates. The prevalence of listeriosis is quite low globally; however, the most recent and deadliest outbreak occurred in South Africa, during which 216 persons lost their lives. L. monocytogenes is endowed with the potential to multiply through a wide range of harsh environmental conditions, forming biofilms on varying surfaces in the food industry, as well as having persistent and antibiotic-resistant cells, which pose a major threat and burden to the ready-to-eat food industry. A more frustrating characteristic of this bacterium is its strain divergence, alongside an increased level of antibiotic resistance registered among the strains of L. monocytogenes recovered from food, humans, and environmental sources, especially to those antibiotics involved in the treatment of human listeriosis. Antibiotic resistance exerted by and among pathogenic food-borne microbes is an ongoing public health menace that continues to be an issue. Against this background, a thorough search into different databases using various search engines was performed, which led to the gathering of salient information that was organised, chronologically, based on Listeria monocytogenes and listeriosis. Altogether, the findings elaborated in this study present up-to date knowledge on different aspects of this pathogen which will improve our understanding of the mystery associated with it and the ways to prevent and control its dissemination through ready-to-eat foods. In addition, constant monitoring of the antibiotic resistance profiles of strains of L. monocytogenes from varying sources detected changes, giving an update on the trend in antibiotic resistance. Overall, monitoring of bacterial contamination serves as the key aspect in the control of the food safety output in the food industry.

Antibacterial Activity of Ocimum tenuiflorum against Drug Resistant Bacteria Isolated from Raw Beef

Recent empirical evidence has acknowledged raw meat, particularly beef, as a significant reservoir for diverse foodborne pathogens and drug-resistant strains, posing severe threat to consumer health. This study aimed to isolate and identify drug-resistant bacteria from raw beef samples, obtained from different butcher shops in Khulna city, Bangladesh, as well as, to determine their susceptibility pattern against Ocimum tenuiflorum extracts. Raw beef samples were randomly collected from various butcher shops, followed by the initial isolation of thirty pure bacterial isolates. Later, 16S rRNA gene amplification and analysis identified twelve distinct bacterial species from those isolates. The antimicrobial susceptibility test results revealed ten of the isolates, including Klebsiella pneumoniae, Aeromonas veronii and Enterobacter hormaechei, to exhibit multidrug resistance pattern. Amoxicillin, nitrofurantoin, and flucloxacillin were found to be ineffective against most isolates. However, the ethanolic extracts of O. tenuiflorum were found effective in inhibiting the growth of eight species at three different concentrations. Subsequent HPLC analysis of O. tenuiflorum reported the presence of five secondary metabolites epicatechin, syringic acid, rutin hydrate, p-coumaric acid, and myricetin as potent contributors to the observed antimicrobial activity. Lastly, in silico binding interaction simulations of the secondary metabolites against five relevant targets predict syringic acid and myricetin to have effective antibacterial properties, primarily mediated by better binding affinity and molecular interactions. Thus, this study identified diverse drug-resistant bacteria in raw beef and provided novel insights into the antibacterial properties of O. tenuiflorum extracts.

Beyond antibiotics: exploring multifaceted approaches to combat bacterial resistance in the modern era: a comprehensive review

Antibiotics represent one of the most significant medical breakthroughs of the twentieth century, playing a critical role in combating bacterial infections. However, the rapid emergence of antibiotic resistance has become a major global health crisis, significantly complicating treatment protocols. This paper provides a narrative review of the current state of antibiotic resistance, synthesizing findings from primary research and comprehensive review articles to examine the various mechanisms bacteria employ to counteract antibiotics. One of the primary sources of antibiotic resistance is the improper use of antibiotics in the livestock industry. The emergence of drug-resistant microorganisms from human activities and industrial livestock production has presented significant environmental and public health concerns. Today, resistant nosocomial infections occur following long-term hospitalization of patients, causing the death of many people, so there is an urgent need for alternative treatments. In response to this crisis, non-antibiotic therapeutic strategies have been proposed, including bacteriophages, probiotics, postbiotics, synbiotics, fecal microbiota transplantation (FMT), nanoparticles (NPs), antimicrobial peptides (AMPs), antibodies, traditional medicines, and the toxin-antitoxin (TA) system. While these approaches offer innovative solutions for addressing bacterial infections and preserving the efficacy of antimicrobial therapies, challenges such as safety, cost-effectiveness, regulatory hurdles, and large-scale implementation remain. This review examines the potential and limitations of these strategies, offering a balanced perspective on their role in managing bacterial infections and mitigating the broader impact of antibiotic resistance.

Menthol in Livestock: Unveiling Its Multifaceted Properties and Future Potential for Sustainable Agriculture

Menthol, the primary active compound in the widely cultivated peppermint plant (Mentha piperita), is well known for its use in human products such as topical analgesics and cold remedies. Menthol's cooling sensation and ability to locally modulate pain through interactions with transient receptor potential channels make it a valuable bioactive compound. In recent years, menthol's antimicrobial, anti-inflammatory, and antioxidative properties have drawn attention in the livestock industry as a natural alternative to synthetic antibiotics in feed additives. This review comprehensively examines the existing literature to assess menthol's effects on animal growth performance, product quality, immune function, gastrointestinal microbial ecosystems, and metabolism across various livestock species. Notably, menthol shows potential for improving feed efficiency, mitigating chronic inflammation and oxidative stress, inhibiting environmental and gastrointestinal pathogens, and enhancing calcium absorption. However, optimal dosages, treatment durations, synergies with other phytogenic compounds, and regulatory mechanisms require further investigation. Additionally, with increasing global temperatures and growing concerns about animal welfare, menthol's cooling, methane-reducing, and analgesic properties present promising opportunities for advancing sustainable livestock practices.

Diurnal oscillations of amino acids dynamically associate with microbiota and resistome in the colon of pigs

BACKGROUND

Nutrients are one of the key determinants of gut microbiota variation. However, the intricate associations between the amino acid (AA) profile and the dynamic fluctuations in the gut microbiota and resistome remain incompletely elucidated. Herein, we investigated the temporal dynamics of AA profile and gut microbiota in the colon of pigs over a 24-hour period, and further explored the dynamic interrelationships among AA profile, microbiota, and resistome using metagenomics and metabolomics approaches.

RESULTS

JTK_circle analysis revealed that both the AA profile and the gut microbiota exhibited rhythmic fluctuations. With respect to the feed intake, all AAs except L-homoserine (PAdj = 0.553) demonstrated significant fluctuations. Over 50% of Lactobacillaceae, Ruminococcaceae, Clostridiaceae, and Eubacteriaceae species reached their peaks during T15 ∼ T21 when 50% of Lachnospiraceae species experienced a trough. The eLSA results showed that most AAs positively correlated with Prevotellaceae species but negatively correlated with Lactobacillaceae and Lachnospiraceae species. Moreover, most of the AAs negatively correlated with the mobile genetic elements Tn916 and istA group but positively correlated with plasmids. Further partial least squares structural equation model analysis indicated that AAs affected the antibiotic resistance gene dynamics through mobile genetic elements and the gut microbiota.

CONCLUSIONS

Taken together, the AA profile and the gut microbiota exhibit robust fluctuations over a day. The AA profile can affect the gut microbiota and resistome in a direct or indirect manner. These findings may provide new insights into a potential strategy for manipulating the gut microbiota and resistome.

Applications of Machine Learning in Food Safety and HACCP Monitoring of Animal-Source Foods

Integrating advanced computing techniques into food safety management has attracted significant attention recently. Machine learning (ML) algorithms offer innovative solutions for Hazard Analysis Critical Control Point (HACCP) monitoring by providing advanced data analysis capabilities and have proven to be powerful tools for assessing the safety of Animal-Source Foods (ASFs). Studies that link ML with HACCP monitoring in ASFs are limited. The present review provides an overview of ML, feature extraction, and selection algorithms employed for food safety. Several non-destructive techniques are presented, including spectroscopic methods, smartphone-based sensors, paper chromogenic arrays, machine vision, and hyperspectral imaging combined with ML algorithms. Prospects include enhancing predictive models for food safety with the development of hybrid Artificial Intelligence (AI) models and the automation of quality control processes using AI-driven computer vision, which could revolutionize food safety inspections. However, handling conceivable inclinations in AI models is vital to guaranteeing reasonable and exact hazard assessments in an assortment of nourishment generation settings. Moreover, moving forward, the interpretability of ML models will make them more straightforward and dependable. Conclusively, applying ML algorithms allows real-time monitoring and predictive analytics and can significantly reduce the risks associated with ASF consumption.

Advancements in Antibacterial Therapy: Feature Papers

Antimicrobial resistance (AMR) is a growing global health crisis that threatens the efficacy of antibiotics and modern medical interventions. The emergence of multidrug-resistant (MDR) pathogens, exacerbated by the misuse of antibiotics in healthcare and agriculture, underscores the urgent need for innovative solutions. (1) Background: AMR arises from complex interactions between human, animal, and environmental health, further aggravated by the overuse and inadequate regulation of antibiotics. Conventional treatments are increasingly ineffective, necessitating alternative strategies. Emerging approaches, including bacteriophage therapy, antimicrobial peptides (AMPs), nanotechnology, microbial extracellular vesicles (EVs), and CRISPR-based antimicrobials, provide novel mechanisms that complement traditional antibiotics in combating resistant pathogens. (2) Methods: This review critically analyzes advanced antibacterial strategies in conjunction with systemic reforms such as antimicrobial stewardship programs, the One Health framework, and advanced surveillance tools. These methods can enhance resistance detection, guide interventions, and promote sustainable practices. Additionally, economic, logistical, and regulatory challenges impeding their implementation are evaluated. (3) Results: Emerging technologies, such as CRISPR and nanotechnology, exhibit promising potential in targeting resistance mechanisms. However, disparities in resource distribution and regulatory barriers hinder widespread adoption. Public-private partnerships and sustainable agriculture practices are critical to overcoming these obstacles. (4) Conclusions: A holistic and integrated approach is essential for mitigating the impact of AMR. By aligning innovative therapeutic strategies with global health policies, fostering interdisciplinary collaboration, and ensuring equitable resource distribution, we can develop a sustainable response to this 21st-century challenge.

Computer-Aided Discovery of Synergistic Drug-Nanoparticle Combinations for Enhanced Antimicrobial Activity

Antibiotic resistance is a critical global public health challenge driven by the limited discovery of antibiotics, the rapid evolution of resistance mechanisms, and persistent infections that compromise treatment efficacy. Combination therapies using antibiotics and nanoparticles (NPs) offer a promising solution, particularly against multidrug-resistant (MDR) bacteria. This study introduces an innovative approach to identifying synergistic drug-NP combinations with enhanced antimicrobial activity. To carry this out, we compiled two groups of data sets to predict the minimal concentration (MC) and zone of inhibition (ZOI) of various drug-NP combinations. CatBoost regression models achieved the best 10-fold cross-validation R2 scores of 0.86 and 0.77, respectively. We then adopted a machine learning (ML)-reinforced genetic algorithm (GA) to identify synergistic antimicrobial NPs. The proposed approach was first validated by reproducing the previous experimental results. As a proof of concept for discovering drug-NP combinations, Au NPs were identified as highly synergistic NPs when paired with chloramphenicol, achieving a minimum bactericidal concentration (MBC) of 71.74 ng/mL against Salmonella typhimurium with a fractional inhibitory concentration index of 6.23 × 10-3. These findings present an effective strategy for identifying synergistic drug-NP combinations, providing a promising approach to combating drug-resistant pathogens and advancing targeted antimicrobial therapies.

Growth performance of neonatal Holstein heifers fed acidified waste milk containing essential oil blend and encapsulated butyrate alone or in combination

Previous research demonstrated the growth-promoting benefits of an essential oil and oligosaccharide blend (Stay Strong, Ralco, Inc.; EO) or an encapsulated sodium butyrate (C4; Ultramix GF, Adisseo, Inc.) fed to neonatal calves. The possibility exists that these technologies may be additive based on their individual mechanisms of action. The study objective was to evaluate EO and C4 alone or in combination when fed to Holstein heifers raised on a commercial Chinese dairy operation. Sixty-four heifers were blocked by calving day and randomly assigned to 1 of 4 treatments (n = 16/treatment) using a randomized complete block design. Treatments were: (1) Control: CON; milk fed 3×/d; (2) EO added to the milk at the rate of 1.50 g/d per head; (3) C4 added to the milk at 1.70 g/d per head; and (4) E4: EO and C4 added to the milk at the rates of 1.50 and 1.70 g/d per head, respectively. Heifers were fed acidified waste milk using an increasing- and decreasing-phase feeding program with weaning on d 56 for a 70-d experiment. Heifer birth weight was a significant covariate with heifers fed EO, C4, and E4, demonstrating greater BW (42.4, 47.0, 46.6, and 48.0 kg for CON, EO, C4, and E4, respectively) gains and ADG (605.0,672.5, 665.7, and 686.7 g/d, respectively) compared with heifers fed CON. Calf starter intake (0.558, 0.584, 0.692, and 0.624 kg/d, respectively) was greater for heifers fed C4 compared with heifers fed CON, with heifers fed EO and E4 being intermediate and similar. Feed conversions (0.439, 0.480, 0.444, and 0.477 kg/kg, respectively) were greater for calves fed EO and E4 compared with calves fed CON. Total days of fecal score = 0 was greater for heifers fed EO and lowest for heifers fed E4, with heifers fed CON and C4 being intermediate. Gains in body length and hip width were greater for heifers fed EO compared with heifers fed CON, C4, and E4. Total-tract apparent fiber (NDF and ADF) digestibility was greater in heifers fed EO and C4, intermediate for heifers fed E4, and lowest for heifers fed CON. Heifers fed EO demonstrated lower fecal Salmonella counts compared with heifers fed CON, C4, and E4. Heifers fed EO and C4 demonstrated greater blood serum total volatile fatty acid concentrations (9.75, 12.91, 11.22, 10.89 µM, respectively, for CON, EO, C4, and E4) compared with heifers fed CON, with heifers fed E4 being intermediate and similar. Heifers fed EO, C4, and E4 demonstrated greater growth performance, but the combination of EO and C4 did not further improve growth performance.

Strip biosensors based on broad-spectrum aptamers and cationic polymers for the on-site rapid detection of tetracycline antibiotics residues in milk

A lateral flow chromatography strip (LFS) is a chromatography-based biosensor with advantages of convenient portability, simple operation and rapid detection. In this study, a novel rapid detection technique of aptamer-based chromatography strip was developed and used for the first time for the residue detection of tetracycline antibiotics (TCs) in various milk samples. In this method, gold nanoparticles (AuNPs) modified by TCs specific aptamers were used as probes, and cationic polymers as capture molecules in a test line (T-line). Meanwhile, the analysis of the gray value of the T-line enabled a linear detection range of 1-300 nM and a limit of detection (LOD) of 0.33 nM for quantitative analysis. The biosensor demonstrated high specificity, good stability, and successfully detected tetracyclines in milk samples with recovery rate of 93.60%-106.20%. This method sets a basis for multi-residue antibiotics detection in diverse samples, showing potential for on-site applications.

Prevalence and Antibiotic Resistance of Escherichia coli Isolated from Raw Cow's Milk

Escherichia coli (E. coli) is one of the most common pathogens in both humans and livestock. This study aimed to investigate the prevalence of E. coli isolated from raw cow milk and evaluate its antimicrobial resistance rates. A total of 1696 milk samples were collected from Romanian dairy farms from 2018 to 2022. E. coli was isolated on various selective agar media, such as Cled agar and Columbia Agar with 5% Sheep Blood. The identification of E. coli was performed by MALDI-TOF MS. E. coli isolates were tested for their susceptibility against 18 commonly used antibiotics in a disk diffusion method. The overall prevalence of E. coli was 22.45% of all isolated pathogens. Antibiogram analysis revealed that 27.51% of E. coli isolates from milk were multidrug-resistant. Resistance was highest for penicillin-novobiocin (87.78%), followed by streptomycin (53.7%). Resistance to six drugs (amoxicillin, streptomycin, kanamycin-cephalexin, marbofloxacin, ampicillin) showed a significant increasing trend over time, while for two drugs (penicillin G-framycetin, doxycycline), a significant decrease was observed. Our results suggest that milk can be a reservoir of bacteria with the potential for infection in humans via the food chain. Furthermore, there is a need for surveillance and monitoring to control the increase in resistance to currently used antimicrobials in dairy farms because the occurrence of multidrug-resistant E. coli isolated from milk poses a health hazard to consumers.

Lincomycin as a growth-promoting antibiotic induces metabolic and immune dysregulation in animals

Since animal growth promoters (AGPs) are used in large quantities and commonly released to the environment from animal farms, it is necessary to determine whether such agents should be regarded as an environmental toxin that poses a threat to the ecosystem and health risk to wildlife. In this study, a multi-omics approach was employed to explore the effects of a representative AGP, lincomycin, on key metabolic and physiological functions of animals, using a mouse model. The results indicated that exposure to lincomycin resulted in a significant increase in growth rate of mice (50.11 %) over an 8 weeks period, during which significant decrease (61.94 %) and increase (68.64 %) in the relative abundance of Firmicutes and Escherichia coli, respectively, was observed in the gut microbiota, indicating that the gut microbiota structure has been altered. Moreover, the mice exhibited altered lipid profiles and liver damage suggestive of early-stage non-alcoholic fatty liver disease (NAFLD). Disruptions in blood glucose and insulin levels associated with type 2 diabetes mellitus (T2DM) were also observed. Furthermore, lincomycin was found to cause suppression in inflammatory responses, as evidenced by the downregulation of related genes and elevated inflammatory mediators, potentially resulting in increased susceptibility to microbial infection. Our findings underscore the detrimental effects of lincomycin on animal health and highlight the necessity for comprehensive toxicological assessments of lincomycin and other AGPs before their environmental release.

Antimicrobial Resistance in the Context of Animal Production and Meat Products in Poland-A Critical Review and Future Perspective

The prevalence of antimicrobial-resistant bacteria in meat and meat products is a significant public health challenge, largely driven by the excessive and inappropriate use of antimicrobials in animal husbandry. In Poland, a key meat producer in Europe, antibiotic-resistant pathogens such as Campylobacter spp., Staphylococcus spp., Enterococcus spp., Listeria monocytogenes, and Enterobacterales have been detected in meat, posing serious risks to consumers. This review examines the use of antimicrobial agents in meat production and the resulting antimicrobial resistance (AMR) in microorganisms isolated from meat products in Poland. The mechanisms of AMR, genetic factors, and prevalence in Poland are presented. It highlights key factors contributing to AMR, such as antibiotic misuse in livestock farming, and discusses the legal regulations governing veterinary drug residues in food. This review emphasizes the importance of monitoring and enforcement to safeguard public health and calls for further research on AMR in the meat industry. Antimicrobial resistance in meat and meat products in Poland is a huge challenge, requiring stricter antibiotic controls in animal husbandry and improved surveillance systems. Additionally, the impact of husbandry practices on the environment and food requires further research. Future efforts should focus on nationwide monitoring, alternative strategies to reduce antibiotic use, and stronger enforcement to combat antimicrobial resistance and protect public health.

Contract governance to reduce antimicrobial overuse in hog farms in China

Antimicrobial resistance caused by the overuse of antimicrobials by farmers is an essential health issue. Currently, signing contracts between farmers and cooperatives has become crucial for small farmers to integrate into the modern agricultural industry chain. Unlike vertical government governance, which aims to intervene in the overuse of antimicrobials by farmers through many mandatory or incentive measures, contract governance refers to the social governance model that clarifies rights and obligations between farmers and cooperatives to ensure the adequate performance of contracts, which is especially beneficial to regulate farmers' safe production behavior such as the standard use of antimicrobials. However, there is a research gap concerning the effectiveness of contract governance in inhibiting farmers' overuse of animal antimicrobials. This study applies propensity score matching and mediation analysis method to assess how contract governance affects the overuse of antimicrobials by hog farmers. The paper uses data from 498 hog farmers of China's Hebei, Henan, and Hubei provinces to explore the impact and underlying mechanisms of contract governance on antimicrobial overuse in agriculture. The results showed that contract governance was found to inhibit the overuse of antimicrobials, with the amount paid for antimicrobials reduced by 118 yuan/household. We found evidence that this effect is exerted through three mechanisms: cooperative supervision (CS), technical guidance (TG), and product premium perception (PP). The CS, TG, and PP mediation effects accounted for 19.94%, 27.90%, and 26.93% of the total impact, respectively. Therefore, policy implications of these results include strengthening the standard of contract signing procedures and the integrity of executing contracts, increasing the market premium for products that meet the antimicrobial residue standards, and enhancing farmers' knowledge and contracting ability.

Veterinary Drug Residues in Food Products of Animal Origin and Their Public Health Consequences: A Review

Veterinary medications used for disease treatment and prevention may remain in animal-origin foods, such as milk, eggs, honey and meat, which could pose a risk to the public's health. These drugs come from different groups of drugs, mostly with antibiotic, anti-parasitic or anti-inflammatory actions, in a range of food matrices including milk, meat or egg. This review is intended to provide the reader with a general insight about the current status of veterinary drug residues in food products of animal origin, detection methods and their public health consequences. The discovery of antimicrobials has led to the development of antibiotics for treating and preventing cattle illnesses and encouraging growth. However, the rise of drug resistance has led to increased antibiotic consumption and resistance among microbes in the animal habitat. This resistance can be passed to humans directly or indirectly through food consumption and direct or indirect interaction. Improper and illegal use, inadequate withdrawal periods and environmental contamination from veterinary drugs are reported to be the major causes for the formation of residue in food products of animal origin. The use of veterinary products above or below the advised level may also result in short- or long-term public health issues, such as the creation of resistant strains of micro-organisms, toxicity, allergy, mutagenesis, teratogenicity and carcinogenetic effects. To ensure consumer safety, veterinary drug residues in food must be under control.

Dual response signal CdTe QDs@ZIF-8 with butterfly spectrum for dual-mode fluorescence/colorimetric detection of tetracycline in animal feeds

In this study, a ratiometric fluorescent sensor CdTe QDs@ZIF-8 with butterfly spectra is successfully constructed by in situ encapsulating mercaptopropionic acid-modified CdTe quantum dots in zeolitic imidazolate framework-8 (ZIF-8) with a simple strategy, and used for the detection of tetracycline in fluorescence/smartphone colorimetry dual-mode. ZIF-8 not only reduces the agglomeration of the quantum dots but also surprisingly generates a new green fluorescence signal at 524 nm while the red fluorescence of the CdTe quantum dots at 650 nm quenches when tetracycline is added. The two opposing fluorescence signals create a butterfly-shaped fluorescence spectrum, allowing the sensor to detect tetracycline over a linear range of 0-70 μM with the detection limit (LOD) of 0.0155 μM by using a ratiometric fluorescence technique. What is more, based on the obvious color change of the fluorescent sensor gradually from red to green under UV light, a highly stable point-of-care testing sensor has been developed for on-site detection of tetracycline through color recognition by smartphones, which can be used for real-time detection of this antibiotic in the range of 0-1000 μM with the LOD of 0.0249 μM. This work provides a simple and efficient method for the on-site detection of tetracycline.

Comparative Characteristics of Immunochromatographic Test Systems for Tylosin Antibiotic in Meat Products

Tylosin (TYL) is a macrolide antibiotic widely used in animal husbandry. Due to associated health risks, there is a demand for sensitive methods for mass screening of TYL in products of animal origin. This article describes the development of lateral flow immunoassays (LFIAs) for TYL detection using direct (anti-TYL antibodies conjugated with nanoparticles) and indirect antibody labeling (anti-species antibodies conjugated with nanoparticles and combined with native anti-TYL antibodies). The choice of LFIA conditions, such as concentrations of hapten-protein conjugates, specific antibodies, and gold nanoparticle (GNP) conjugates with antibodies, as well as incubation time of reagents and the concentration of detergent in the sample buffer, is presented. The achieved limits of TYL detection using LFIAs with indirect labeling were 0.8 ng/mL (visual) and 0.07 ng/mL (instrumental), compared to 4 ng/mL (visual) and 0.4 ng/mL (instrumental) for the case of direct labeling. The sensitivity of the LFIA using the indirect format was up to seven times higher, allowing the determination of the target analyte at low concentrations. TYL detection in ground meat using LFIA with indirect antibody labeling ranged from 76-119%.

Antibiotic Resistance Genes in Global Food Transformation System: Edible Insects vs. Livestock

Antibiotic-resistant genes (ARGs) pose a significant threat to the global food transformation system. The increasing prevalence of ARGs in food has elicited apprehension about public health safety. The widespread dissemination of ARGs in food products, driven by the inappropriate use of antibiotics, presents significant adversity for the safety of emerging future food sources such as edible insects. As the world faces increasing challenges related to food security, climate change, and antibiotic resistance, edible insects offer a sustainable and resilient food source. The intriguing possibility of edible insects serving as a less conducive environment for ARGs compared to livestock warrants further exploration and investigation. In this recent work, we listed ARGs from edible insects detected so far by in vitro approaches and aimed to construct a fair comparison with ARGs from livestock based on relevant genes. We also presented our argument by analyzing the factors that might be responsible for ARG abundance in livestock vs. edible insects. Livestock and edible insects have diverse gut microbiota, and their diets differ with antibiotics. Consequently, their ARG abundance may vary as well. In addition, processed edible insects have lower levels of ARGs than raw ones. We hypothesize that edible insects could potentially contain a lower abundance of ARGs and exhibit a diminished ability to disseminate ARGs relative to livestock. A regulatory framework could help intercept the increasing prevalence of ARGs. Due diligence should also be taken when marketing edible insects for consumption.

Hop as a phytogenic alternative to antibiotic growth promoters in poultry production

With the rapid growth of the world's population, the demand for food is also increasing. Poultry accounts for 40% of the global meat sector and therefore represents a significant area for further growth. One starting point for increasing production is to refine the composition of feed to improve the efficiency of growth and nutrient utilization, prevent disease and at the same time reduce environmental impact. Similar considerations have led to the long-standing sub-therapeutic use of antibiotics as growth promoters in animal husbandry, which is associated with the threat of rising antimicrobial resistances and the resulting consequences for human and animal health. In order to circumvent these drawbacks, an increasing number of alternative feed additives are becoming more prevalent. The use of phytogenic feed additives, which includes hops (Humulus lupulus), is regarded as a viable alternative. In addition to its natural availability, hops have been demonstrated to exhibit antimicrobial effects and there is increasing evidence of growth-promoting effects in vivo. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Exploring the antibiotic resistance genes removal dynamics in chicken manure by composting

Prolonged antibiotic usage in livestock farming leads to the accumulation of antibiotic resistance genes in animal manure. Composting has been shown as an effective way of removing antibiotic resistance from manures, but the specific mechanisms remain unclear. This study used time-series sampling and metagenomics to analyse the resistome types and their bacterial hosts in chicken manures. Composting significantly altered the physicochemical properties and microbiome composition, reduced antibiotic resistance genes by 65.71 %, mobile genetic elements by 68.15 % and horizontal gene transfer frequency. Source tracking revealed that Firmicutes, Actinobacteria, and Proteobacteria are the major bacterial hosts involved in the resistome and gene transfer events. Composting reduces the resistome risk by targeting pathogens such as Staphylococcus aureus. Structural equation modelling confirmed that composting reduces resistome risk by changing pH and pathogen abundance. This study demonstrates that composting is an effective strategy for mitigating resistome risk in chicken manure, thereby supporting the One Health initiative.

Food Additives Derived from Fruits and Vegetables for Sustainable Animal Production and Their Impact in Latin America: An Alternative to the Use of Antibiotics

The production of healthy animal-derived food entails the effective control of foodborne pathogens and strategies to mitigate microbial threats during rearing. Antibiotics have been traditionally employed in animal farming to manage bacterial infections. However, the prohibition of antibiotic growth promoters in livestock farming has brought significant changes in animal production practices. Although antibiotics are now restricted to treating and preventing bacterial infections, their overuse has caused serious public health issues, including antibiotic resistance and the presence of antibiotic residues in food and wastewater. Therefore, sustainable animal production is crucial in reducing the spread of antibiotic-resistant bacteria. Annually, 40-50% of fruit and vegetable production is discarded worldwide. These discards present significant potential for extracting value-added ingredients, which can reduce costs, decrease waste, and enhance the food economy. This review highlights the negative impacts of antibiotic use in livestock farming and stresses the importance of analyzing the challenges and safety concerns of extracting value-added ingredients from fruit and vegetable co-products at an industrial scale. It also explores the current trends in reducing antibiotic use in livestock, with a focus on Latin American contexts. Finally, the suitability of using value-added ingredients derived from fruit and vegetable co-products for animal feeds is also discussed.

Antenna effect enhanced ECL immunoassay using microfloral europium porphyrin coordination polymers based on Eu3+ and TCPP for the detection of chloramphenicol in foods

The "antenna effect" is one of the most important energy transfer modes in lanthanide light-emitting polymers. In this study, novel luminescent nanostructured coordination polymers (Eu-PCP) were synthesized in one step using Eu3+ as the central metal ion and 5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (TCPP) as the organic ligand. The unique "antenna effect" observed between Eu3+ and TCPP leads to a substantial improvement in the electrochemiluminescence (ECL) emission efficiency. Eu-PCP exhibits good cathodic ECL characteristics. Additionally, Au@SnS2 nanosheets exhibit favorable electrical conductivity, biocompatibility, and a significant specific surface area. This makes them a suitable choice as substrate materials for the modification of electrode surfaces and capturing antigens. Being well known, the development of sensitive and rapid methods to detect chloramphenicol is essential for food safety. Based on this, we report a novel competitive electrochemiluminescence immunoassay to achieve ultra-sensitive and highly specific detection of chloramphenicol. The linear range was 0.0002-500 ng mL-1 and the detection limit was 0.09 pg mL-1. Apart from that, the experimental results proved that it provided a new analytical tool for the detection of antibiotic residues in food safety.

Spread of livestock-associated methicillin-resistant Staphylococcus aureus in poultry and its risks to public health: A comprehensive review

The livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) strains are prevalent in the poultry farming environment and are a common component of the bacterial microbiota on the skin and mucous membranes of healthy animals. The origin and spread of LA-MRSA are attributed to the use of antibiotics in animals, and close contact between people and different animal species increases the risk of animal exposure to humans. The epidemiology of LA-MRSA in poultry significantly changed when ST398 and ST9 were found in food-producing animals. The significance of LA-MRSA and zoonotic risk associated with handling and processing foods of avian origin is highlighted by the LA-MRSA strain's ability to infect chickens. People who work with poultry are more prone to contract LA-MRSA than the general population. There is scientific consensus that individuals who have close contact with chickens can become colonized and subsequently infected with LA-MRSA; these individuals could include breeders, medical professionals, or personnel at chicken slaughterhouses. The prevention of LA-MRSA infections and diseases of poultry origin requires taking precautions against contamination across the entire chicken production chain.

Phytochemical characterization and biological activities of Inula viscosa L. Aiton: a promising plant from Turkey

The methanol extract of Inula viscosa (IVM) was investigated for its antioxidant potential using the DPPH and ABTS radical scavenging as well as iron chelating assays (ICA). The total phenol (TPC) and flavonoid contents (TFC) of IVM were determined using the Folin-Ciocalteu and aluminum trichloride methods, respectively. Antimicrobial activity of different concentrations of I. viscosa methanol extract was investigated by disc diffusion and broth microdilution method. The IVM extract was found to be containing TPC (236.78 ± 7.63 mg GAE/g) and TFC (94.36 ± 1.86 mg QE/g). Antioxidant activity IC50 values for the DPPH, ABTS and ICA assays were found to be 277.7 ± 3.68, 2.44 ± 0.02, and 222.1 ± 0.71 µg/mL, respectively. The MIC values of the IVM on the tested microorganisms ranged from 0.48 to 7.81 mg/mL. Furthermore, IVM extract was demonstrated 18.32 ± 1.37%, 23.06 ± 1.05%, 4.72 ± 0.13%, 15.13 ± 0.37% and 37.64 ± 4.02% inhibition against tyrosinase, α-amylase, α-glucosidase, AChE and BChE, respectively. In the results of LC-MS/MS analysis, acacetin, quercetin, chlorogenic acid and protocatechuic acid were determined as most dominant compounds. These findings suggested that this plant may be a natural resource for creating novel medicinal compounds.

Role of immunomodulatory probiotics in alleviating bacterial diarrhea in piglets: a systematic review

Diarrhea is a common enteric disease in piglets that leads to high mortality and economic losses in swine production worldwide. Antibiotics are commonly used to prevent or treat diarrhea in piglets. However, irrational antibiotic use contributes to the development of resistance in bacteria and antibiotic residues in animal products, threatening public health, while causing gut microbiota dysbiosis and antibiotic-resistant bacterial infection in piglets. Therefore, the quest for alternative products (such as probiotics, prebiotics, organic acids, enzymes, essential oils, medium-chain fatty acids, zinc, and plant extracts) has recently been clearly emphasized through the increase in regulations regarding antibiotic use in livestock production. These antibiotic alternatives could lower the risk of antibiotic-resistant bacteria and meet consumer demand for antibiotic-free food. Several antibiotic alternatives have been proposed, including immunomodulatory probiotics, as candidates to reduce the need for antimicrobial therapy. Many studies have revealed that probiotics can avert and cure bacterial diarrhea by regulating the gut function and immune system of piglets. In this review, we focus on the major pathogenic bacteria causing piglet diarrhea, the research status of using probiotics to prevent and treat diarrhea, their possible mechanisms, and the safety issues related to the use of probiotics. Supplementation with probiotics is a possible alternative to antibiotics for the prevention or treatment of bacterial diarrhea in piglets. Furthermore, probiotics exert beneficial effects on feed efficiency and growth performance of piglets. Therefore, appropriate selection and strategies for the use of probiotics may have a positive effect on growth performance and also reduce diarrhea in piglets. This review provides useful information on probiotics for researchers, pig nutritionists, and the additive industry to support their use against bacterial diarrhea in piglets.

Dietary Supplementation of Lactococcus lactis subsp. lactis BIONCL17752 on Growth Performance, and Gut Microbiota of Broiler Chickens

The rapid rise of antimicrobial resistance (AMR) is a global concern, being triggered by the overuse or misuse of antibiotics in poultry farming sector. We evaluated Lactococcus lactis subsp. lactis BIONCL17752 strain, and characterized its probiotic potential to endure hostile gastrointestinal conditions. Genome sequencing analysis revealed probiotics traits, and gene clusters involved in bacteriocins, lactococcin A, and sactipeptides production. The absence of genes for antibiotic resistance, virulence, and biogenic amine production indicates the potential of probiotic strain. The BIONCL17752 strain was explored for antibiotic-free feed supplement for growth promotor in broiler chicken. The feed supplemented with 4 × 109 CFU/kg of probiotic strain, in combination with various concentrations of fructooligosaccharides (FOS) 1.0, 2.5, and 5.0 kg/tonne in starter, grower, and finisher diets, respectively. A significant improvement of body weight 152 to 171 g/bird (p < 0.05), and a low feed conversion ratio (FCR) of 1.62, was achieved without using synthetic antibiotics for growth promotion. The results of biochemical, hematological, and histological examinations showed normal features, indicating that the treatment had no harmful effects on the bird's health. Reduced levels of cholesterol, triglycerides, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) in serum are an indication of the health benefits for the treated birds. Microbial community analysis of fecal samples of poultry birds exhibited a higher abundance of Bacteroidetes, Firmicutes, Proteobacteria, Actinobacteria, and Fusobacteria. Probiotic treatment resulted in reduced Firmicutes and increased Bacteroidetes (F/B ratio) in the broiler's gut which highlights the benefits of probiotic dietary supplements. Importantly, the probiotic-fed group exhibited a high abundance of carbohydrate-active enzymes (CAZyme) such as glycoside hydrolases (GH), glycoside transferases (GT), and carbohydrate-binding module (CBM) hydrolases which are essential for the degradation of complex sugar molecules. The probiotic potential of the BIONCL17752 strain contributes to broilers' health by positively affecting intestinal microbiota, achieving optimal growth, and lowering mortality, demonstrating the economic benefits of probiotic treatment in organic poultry farming.

Holstein calves fed a milk replacer with a direct fed microbial (DFM) and a starter containing a botanical extract or a DFM alone or in combination

Botanical extracts (BE; Apex, Adisseo, North America) have demonstrated enhanced DMI and improved gut health, while direct fed microbials (DFM), such as Lactobacillus acidophilus fermentation product (EX: Excell, Pacer Technology, Inc.), has demonstrated improved gut health and growth performance of growing Holstein calves. The hypothesis was this combination may be synergistic to neonatal calf growth performance and intestinal health. Eighty, 2-5-d old Holstein bull calves were blocked by BW and randomly assigned to one of 8 treatments arranged in a 2 × 4 factorial using a randomized complete block design. The main factors were milk replacer (MR) without (Control) and with EX added at 5 g/d fed and calf starter (CS). The CS containing no additives (Control); CS containing BE at 496 mg/kg; CS containing EX at 2.50 g/kg; and CS containing BE and EX at the same inclusion rates. The MR were fed 2x/d at 0630 and 1800 h along with free choice CS (amounts and orts weighed d) and water. Weaning occurred after d 42 for the 56-d experiment. No MR by CS main effects interactions were detected for BW, ADG, CS intake, total DMI, feed efficiency or body frame gain parameters. The BW gain (38.0 and 39.3 kg for control and EX, respectively) for MR main effect was similar for calves fed both MR, while CS main effects (38.7, 39.7, 39.2, and 37.2 kg for control, BE, EX, and BE&EX, respectively) was similar among all CS. Gains in body length (10.6 and 10.8 cm), hip width (4.5 and 4.5 cm), withers height, (10.5 and 10.6 cm) heart girth (18.6 and 19.9 cm) and body length (9.1 and 7.9 cm) were similar for calves fed both MR, while CS main effects for hip height (10.5, 10.2, 10.3, and 10.9 cm), hip width (4.7, 4.6, 4.4, and 4.3 cm) withers height (10.7, 10.9, 10.3 and 10.6 cm), heart girth (19.9, 18.9, 18.9, and 19.4 cm), and body length (11.7, 9.1, 8.3, and 8.4 cm) were similar. Total days of a fecal score = 0 was greater for calves fed Control MR and BE CS compared with calves fed Contol MR and the combination of BE&EX with calves fed the remaining treatments being intermediated and similar. This study demonstrated little calf growth performance and health benefits when feeding a BE or EX alone or in combination compared with calves fed control.

Tackling salmonellosis: A comprehensive exploration of risks factors, impacts, and solutions

Salmonellosis, caused by Salmonella species, is one of the most common foodborne illnesses worldwide with an estimated 93.8 million cases and about 155,00 fatalities. In both industrialized and developing nations, Salmonellosis has been reported to be one of the most prevalent foodborne zoonoses and is linked with arrays of illness syndromes such as acute and chronic enteritis, and septicaemia. The two major and most common Salmonella species implicated in both warm-blooded and cold-blooded animals are Salmonella bongori and Salmonella enterica. To date, more than 2400 S. enterica serovars which affect both humans and animals have been identified. Salmonella is further classified into serotypes based on three primary antigenic determinants: somatic (O), flagella (H), and capsular (K). The capacity of nearly all Salmonella species to infect, multiply, and survive in human host cells with the aid of their pathogenic and virulence arsenals makes them deadly and important public health pathogens. Primarily, food-producing animals such as poultry, swine, cattle, and their products have been identified as important sources of salmonellosis. Additionally, raw fruits and vegetables are among other food types that have been linked to the spread of Salmonella spp. Based on the clinical manifestation of human salmonellosis, Salmonella strains can be categorized as either non-typhoidal Salmonella (NTS) and typhoidal Salmonella. The detection of aseptically collected Salmonella in necropsies, environmental samples, feedstuffs, rectal swabs, and food products serves as the basis for diagnosis. In developing nations, typhoid fever due to Salmonella Typhi typically results in the death of 5%-30% of those affected. The World Health Organization (WHO) calculated that there are between 16 and 17 million typhoid cases worldwide each year, with scaring 600,000 deaths as a result. The contagiousness of a Salmonella outbreak depends on the bacterial strain, serovar, growth environment, and host susceptibility. Risk factors for Salmonella infection include a variety of foods; for example, contaminated chicken, beef, and pork. Globally, there is a growing incidence and emergence of life-threatening clinical cases, especially due to multidrug-resistant (MDR) Salmonella spp, including strains exhibiting resistance to important antimicrobials such as beta-lactams, fluoroquinolones, and third-generation cephalosporins. In extreme cases, especially in situations involving very difficult-to-treat strains, death usually results. The severity of the infections resulting from Salmonella pathogens is dependent on the serovar type, host susceptibility, the type of bacterial strains, and growth environment. This review therefore aims to detail the nomenclature, etiology, history, pathogenesis, reservoir, clinical manifestations, diagnosis, epidemiology, transmission, risk factors, antimicrobial resistance, public health importance, economic impact, treatment, and control of salmonellosis.

Quantitative determination of tetracyclines in medicated feed for food-producing animals by HPLC-DAD

Tetracyclines are a group of antibiotic substances largely administered through medicated feed to control diseases in food-producing animals. Fine dosing of antibiotics contained in medicated feed is crucial for the success of the treatment as well as minimising potential threats such as the spread of antimicrobial resistance and the transfer of antibiotic residues in food. A rapid analytical method based on HPLC with diode array detection (HPLC-DAD) was developed to quantify oxytetracycline, chlortetracycline and doxycycline in medicated feed. The reported method underwent in-house validation and was found to be suitable for the quantification of three target tetracyclines within the concentration range of 40-1000 mg kg-1 in official routine analysis. The method was applied to 103 official samples in the framework of the Italian National Plan on animal feed during the years 2021-2023 and nine non-compliant concentrations were identified in swine and fish feed samples.

The two faces of antibiotics: an overview of the effects of antibiotic residues in foodstuffs

Antibiotics, which have been used for many years to treat infections, also play an important role in food contamination with antibiotic residues. There is also unnecessary use of antibiotics, particularly to increase production efficiency. Non-compliance with withdrawal periods and maximum residue limits (MRLs) for antibiotics used in food-producing animals results in undesirable events, such as allergic reactions, teratogenicity, carcinogenicity, changes in the microbiota and, in particular, antibiotic resistance. Therefore, it may be useful to avoid unnecessary use of antibiotics, to limit the use of antibiotics and to turn to alternatives that can be used instead of antibiotics. The aim of this review is to provide information on the undesirable effects of antibiotic residues in food-producing organisms and in the environment, their determination, and the precautions that can be taken.

Veterinary Drug Residues in the Food Chain as an Emerging Public Health Threat: Sources, Analytical Methods, Health Impacts, and Preventive Measures

Veterinary medications are necessary for both contemporary animal husbandry and food production, but their residues can linger in foods obtained from animals and pose a dangerous human risk. In this review, we aim to highlight the sources, occurrence, human exposure pathways, and human health effects of drug residues in food-animal products. Following the usage of veterinary medications, pharmacologically active compounds known as drug residues can be found in food, the environment, or animals. They can cause major health concerns to people, including antibiotic resistance development, the development of cancer, teratogenic effects, hypersensitivity, and disruption of normal intestinal flora. Drug residues in animal products can originate from variety of sources, including water or food contamination, extra-label drug use, and ignoring drug withdrawal periods. This review also examines how humans can be exposed to drug residues through drinking water, food, air, and dust, and discusses various analytical techniques for identifying these residues in food. Furthermore, we suggest some potential solutions to prevent or reduce drug residues in animal products and human exposure pathways, such as implementing withdrawal periods, monitoring programs, education campaigns, and new technologies that are crucial for safeguarding public health. This review underscores the urgency of addressing veterinary drug residues as a significant and emerging public health threat, calling for collaborative efforts from researchers, policymakers, and industry stakeholders to develop sustainable solutions that ensure the safety of the global food supply chain.

CATH-2-derived antimicrobial peptide inhibits multidrug-resistant Escherichia coli infection in chickens

Avian colibacillosis (AC), caused by infection with Escherichia coli (E. coli), is a major threat to poultry health, food safety and public health, and results in high mortality and significant economic losses. Currently, new drugs are urgently needed to replace antibiotics due to the continuous emergence and increasing resistance of multidrug-resistant (MDR) strains of E. coli caused by the irrational use of antibiotics in agriculture and animal husbandry. In recent years, antimicrobial peptides (AMPs), which uniquely evolved to protect the host, have emerged as a leading alternative to antibiotics in clinical settings. CATH-2, a member of the antimicrobial cathelicidin peptide family, has been reported to have antibacterial activity. To enhance the antimicrobial potency and reduce the adverse effects on animals, we designed five novel AMPs, named C2-1, C2-2, C2-3, C2-4 and C2-5, based on chicken CATH-2, the secondary structures of these AMPs were consistently α-helical and had an altered net charge and hydrophobicity compared to those of the CATH-2 (1-15) sequences. Subsequently, the antimicrobial activities of CATH-2 (1-15) and five designed peptides against MDR E. coli were evaluated in vitro. Specifically, C2-2 showed excellent antimicrobial activity against either the ATCC standard strain or veterinary clinical isolates of MDR E. coli, with concentrations ranging from 2-8 μg/mL. Furthermore, C2-2 maintained its strong antibacterial efficacy under high temperature and saline conditions, demonstrating significant stability. Similarly, C2-2 retained a high level of safety with no significant hemolytic activity on chicken mature red blood cells or cytotoxicity on chicken kidney cells over the concentration range of 0-64 μg/mL. Moreover, the administration of C2-2 improved the survival rate and reduced the bacterial load in the heart, liver and spleen during MDR E. coli infection in chickens. Additionally, pathological damage to the heart, liver and intestine was prevented when MDR E. coli infected chickens were treated with C2-2. Together, our study showed that C2-2 may be a promising novel therapeutic agent for the treatment of MDR E. coli infections and AC.

Rapid detection of major enterotoxin genes and antibiotic resistance of Staphylococcus aureus isolated from raw milk in the Yazd province, Iran

INTRODUCTION

Raw milk is a nutrient-rich food, but it may harbour harmful bacteria, such as enterotoxigenic Staphylococcus aureus (S. aureus), which can cause staphylococcal food poisoning. Antibiotic resistance of S. aureus in raw milk can increase the risk of such infections, particularly among susceptible individuals.

OBJECTIVE

This study aimed to investigate the prevalence of enterotoxin genes a, d, g, i and j and the antibiotic resistance of S. aureus isolated from raw milk samples.

METHODS

During a 6-month sampling period, 60 raw milk specimens were obtained from diverse locations in Yazd province, Iran. Antibiogram profiling was conducted via the disc diffusion method. In addition, staphylococcal enterotoxin (SE) genes a, d, g, i, and j were detected through real-time PCR analysis.

RESULTS

Bacteriological assays confirmed the presence of S. aureus in 11 samples (18.3%). All isolates demonstrated 100% resistance to penicillin G but exhibited sensitivity to vancomycin, while resistance to other antibiotics ranged from 36.4% to 45.5%. The prevalence of enterotoxin genes in these strains showed variable distribution, with sea being the predominant SE (45.5%), followed by sed (36.4%), seg (18.2), sej and sei (9.1% each).

CONCLUSIONS

This study discovered the presence of multiple enterotoxins in S. aureus strains obtained from raw milk samples. These strains also demonstrated resistance to a variety of antibiotics. Since enterotoxigenic S. aureus is known to cause human food poisoning, monitoring food hygiene practices, especially during raw milk production, is critical.

Rapid testing of antibiotic residues to increase food safety awareness of animal origin

Background and Aim

Antibiotics are used to improve growth, reduce disease, and decrease mortality in animals grown for food. The government regulates and prohibits the use of antibiotics, in particular, the use of antibiotic growth promoter (AGP) in livestock; however, it is not yet known whether the use of antibiotics is in accordance with regulations so that there are no antibiotic residues in food of animal origin. To ensure food safety of animal origin and to raise awareness of food safety, it is necessary to detect antibiotic residues in fish, eggs, and chicken meat from Yogyakarta Special Province through monitoring and monitoring. To ensure food safety and regulatory compliance in food samples, antibiotic residue screening techniques are essential. A number of methods, such as time-consuming and costly chromatographic and spectroscopic methods, have been developed for the detection of antibiotic residues in food samples; however, not all laboratories have these facilities. Therefore, a rapid diagnosis of food of animal origin is required. The purpose of this study was to rapidly test antibiotic residues by using Premi®test kits (R-Biopharm AG, Germany) to increase awareness of food safety of animal origin.

Materials and Methods

We tested 345 animal-based food samples from traditional markets, supermarkets, and central markets in five districts of Yogyakarta Special Province for antibiotic residues using rapid test kits and observation questionnaires to identify risk factors.

Results

The presence of antibiotic residues in food-animal origin samples from the Yogyakarta region had an antibiotic residue level of 9.28% (32/345), consisting of fish samples 11.3% (18/97), eggs 15.65% (1/114), and chicken meat samples 0.87% (13/102). The highest percentage of samples positive for residual antibiotics was 21.9% (7/32) from supermarket meat samples. The highest amounts of antibiotic residues were found in fish samples collected from Sleman Regency, up to 25% (8/32), whereas in supermarket fish samples, there were as high as 18.8% (6/32).

Conclusion

Antibiotic residues in animal-based food can be attributed to various factors, including product source, transportation conditions, and environmental conditions. The widespread distribution of antibiotic residues in fish comes from environmental conditions during maintenance, distribution, and retailing. Monitoring antibiotic residue prevalence in food-animal origins, particularly chicken meat, eggs, and fish, is crucial for improving animal food quality and safety.

Effect of wheat crops on the persistence and attenuation of antibiotic resistance genes in soil after swine wastewater application

Swine wastewater (SW) application introduces antibiotic resistance genes (ARGs) into farmland soils. However, ARG attenuation in SW-fertigated soils, especially those influenced by staple crops and soil type, remains unclear. This study investigated twelve soil ARGs and one mobile genetic element (MGE) in sandy loam, loam, and silt loam soils before and after SW application in wheat-planted and unplanted soils. The results revealed an immediate increase in the abundance of ARGs in soil by two orders of magnitude above background levels following SW application. After SW application, the soil total ARG abundance was attenuated, reaching background levels at 54 days; However, more individual ARGs were detected above the detection limit than pre-application. Among the 13 genes, acc(6')-lb, tetM, and tetO tended to persist in the soil during wheat harvest. ARG half-lives were up to four times longer in wheat-planted soils than in bare soils. Wheat planting decreased the persistence of acc(6')-lb, ermB, ermF, and intI2 but increased the persistence of others such as sul1 and sul2. Soil type had no significant impact on ARG and MGE fates. Our findings emphasize the need for strategic SW application and the consideration of crop cultivation effects to mitigate ARG accumulation in farmland soils.

Physicochemical properties, mechanism of action of lycopene and its application in poultry and ruminant production

Lycopene is a kind of natural carotenoid that could achieve antioxidant, anti-cancer, lipid-lowering and immune-improving effects by up-regulating or down-regulating genes related to antioxidant, anti-cancer, lipid-lowering and immunity. Furthermore, lycopene is natural, pollution-free, and has no toxic side effects. The application of lycopene in animal production has shown that it could improve livestock production performance, slaughter performance, immunity, antioxidant capacity, intestinal health, and meat quality. Therefore, lycopene as a new type of feed additive, has broader application prospects in many antibiotic-forbidden environments. This article serves as a reference for the use of lycopene as a health feed additive in animal production by going over its physical and chemical characteristics, antioxidant, lipid-lowering, anti-cancer, and application in animal production.

A comprehensive review on the fate and impact of antibiotic residues in the environment and public health: A special focus on the developing countries

The widespread application of antibiotics in human and veterinary medicine has led to the pervasive presence of antibiotic residues in the environment, posing a potential hazard to public health. This comprehensive review aims to scrutinize the fate and impact of antibiotic residues, with a particular focus on the context of developing nations. The investigation delves into the diverse pathways facilitating the entry of antibiotics into the environment and meticulously examines their effects on human health. The review delineates the current state of antibiotic residues, evaluates their exposure in developing nations, and elucidates existing removal methodologies. Additionally, it probes into the factors contributing to the endurance and ecotoxicity of antibiotic residues, correlating these aspects with usage rates and associated mortalities in these nations. The study also investigates removal techniques for antibiotic residues, assessing their efficiency in environmental compartments. The concurrent emergence of antibiotic-resistant bacteria, engendered by antibiotic residues, and their adverse ecological threats underscore the necessity for enhanced regulations, vigilant surveillance programs, and the adoption of sustainable alternatives. The review underlines the pivotal role of public education and awareness campaigns in promoting responsible antibiotic use. The synthesis concludes with strategic recommendations, strengthening the imperative for further research encompassing comprehensive monitoring, ecotoxicological effects, alternative strategies, socio-economic considerations, and international collaborations, all aimed at mitigating the detrimental effects of antibiotic residues on human health and the environment. PRACTITIONER POINTS: Antibiotic residues are widely distributed in different environmental compartments. Developing countries use more antibiotics than developed countries. Human and veterinary wastes are one of the most responsible sources of antibiotic pollution. Antibiotics interact with biological systems and trigger pharmacological reactions at low doses. Antibiotics can be removed using modern biological, chemical, and physical-chemical techniques.

Sulfamethoxazole removal from wastewater via anoxic/oxic moving bed biofilm reactor: Degradation pathways and toxicity assessment

The effects of sulfamethoxazole (SMZ), an antibiotic commonly detected in the water environment, on the performance of a single staged anoxic/oxic moving bed biofilm reactor (A/O MBBR), was investigated. The anoxic zone played a key role in the removal of SMZ with a percentage of contribution accounting for around 85% in the overall removal. Denitrifying heterotrophic microbes present in the anoxic zone showed relatively more resistance to higher SMZ loads. It was found that in extracellular polymeric substances, protein content was increased consistently with the increase in SMZ concentration. Based on the detected biotransformation products, four degradation pathways were proposed and the toxicity was evaluated. Metagenomic analysis revealed that at higher SMZ load the activity of genera, such as Proteobacteria and Actinobacteria was significantly affected. In summary, proper design and operation of staged A/O MBBR can offer a resilient and robust treatment towards SMZ removal from wastewater.

Residues of veterinary antibiotics in manures from pig and chicken farms in a context of antimicrobial use reduction by implementation of health and welfare plans

The use of antibiotics in food-producing animals can induce the presence of residual substances in manure, which are then released into the environment and may contribute to soil and groundwater contamination. During the on-farm implementation of strategies to improve animal health and welfare in chicken and pig farms, the consequences of antibiotic use were evaluated in terms of the occurrence and levels of antibiotic residues in manure. A set of 35 broiler farms from Cyprus, Greece, the Netherlands and 40 pig farms from France and Italy provided a total of 350 manure samples. The primary objective was to develop a specific LC/MS/MS method capable of quantifying antibiotic residues in both types of manure. The method was able to detect fifteen antibiotics belonging to nine classes, with validated limits of quantification of 10-20 μg/kg, and accuracies ranging from 81% to 138%. With the exception of amoxicillin, which was never detected in any manure, all antibiotics used were detected in manure from treated animals with typical concentrations ranging from 10 to 99198 μg/kg for both chickens and pigs. The occurrence of residual antibiotics was higher in chicken than in pig manure, especially for fluoroquinolones and doxycycline which were detected in 89% and 100% of the chicken manure, respectively, and in 28% of the pig manure. The impact of the health plans on the antibiotic load manure was assessed by measuring for each farm the ratio of the sum of all antibiotic concentrations measured after and before the implementation of the plan. The results showed that, in addition to the frequency of treatments, the class of antibiotic used is an important factor to consider as it strongly influences the stability/instability of the compounds, i.e. their ability to persist in the manure of food-producing animals.

Food Safety Issues in the Oltrepò Pavese Area: A SERS Sensing Perspective

Handly and easy-to-use optical instrumentation is very important for food safety monitoring, as it provides the possibility to assess law and health compliances at every stage of the food chain. In particular, the Surface-enhanced Raman Scattering (SERS) method appears highly promising because the intrinsic drawback of Raman spectroscopy, i.e., the natural weakness of the effect and, in turn, of the signal, is overcome thanks to the peculiar interaction between laser light and plasmonic excitations at the SERS substrate. This fact paved the way for the widespread use of SERS sensing not only for food safety but also for biomedicine, pharmaceutical process analysis, forensic science, cultural heritage and more. However, the current technological maturity of the SERS technique does not find a counterpart in the recognition of SERS as a routine method in compliance protocols. This is mainly due to the very scattered landscape of SERS substrates designed and tailored specifically for the targeted analyte. In fact, a very large variety of SERS substrates were proposed for molecular sensing in different environments and matrices. This review presents the advantages and perspectives of SERS sensing in food safety. The focus of the survey is limited to specific analytes of interest for producers, consumers and stakeholders in Oltrepò Pavese, a definite regional area that is located within the district of Pavia in the northern part of Italy. Our attention has been addressed to (i) glyphosate in rice fields, (ii) histamine in a world-famous local product (wine), (iii) tetracycline, an antibiotic often detected in waste sludges that can be dangerous, for instance in maize crops and (iv) Sudan dyes-used as adulterants-in the production of saffron and other spices, which represent niche crops for Oltrepò. The review aims to highlight the SERS performance for each analyte, with a discussion of the different methods used to prepare SERS substrates and the different reported limits of detection.

Gut Microbiota-Derived 5-Hydroxyindoleacetic Acid Alleviates Diarrhea in Piglets via the Aryl Hydrocarbon Receptor Pathway

With the improvement in sow prolificacy, formula feeding has been increasingly used in the pig industry. Diarrhea remains a serious health concern in formula-fed (FF) piglets. Fecal microbiota transplantation (FMT) is an efficacious strategy to reshape gut microbiota and the metabolic profile for treating diarrhea. This study aims to investigate whether FMT from breast-fed piglets could alleviate diarrhea in FF piglets. The piglets were randomly assigned to the control (CON) group, FF group, and FMT group. Our results showed that FF piglets exhibited a higher diarrhea incidence, damaged colonic morphology, and disrupted barrier function. In contrast, FMT treatment normalized the morphology and barrier function. FMT suppressed the JNK/MAPK pathway and production of proinflammatory cytokines. Additionally, FF piglets had a lower abundance of the beneficial bacterial genus Bifidobacterium compared to CON piglets. Following FMT administration, Bifidobacterium was restored. Meanwhile, 5-HIAA, a metabolite of tryptophan, and AHR-responsive CYP1A1 and CYP1B1 were upregulated. Importantly, integrated multiomics analysis revealed a strong positive correlation between Bifidobacterium and 5-HIAA. In vitro, 5-HIAA supplementation reversed the LPS-induced disruption of tight junctions and production of proinflammatory cytokines in IPEC-J2 cells. In conclusion, FMT reduced diarrhea incidence and improved growth performance. The alleviative effect of FMT on diarrhea was associated with Bifidobacterium and 5-HIAA.

A South African Perspective on the Microbiological and Chemical Quality of Meat: Plausible Public Health Implications

Meat comprises proteins, fats, vitamins, and trace elements, essential nutrients for the growth and development of the body. The increased demand for meat necessitates the use of antibiotics in intensive farming to sustain and raise productivity. However, the high water activity, the neutral pH, and the high protein content of meat create a favourable milieu for the growth and the persistence of bacteria. Meat serves as a portal for the spread of foodborne diseases. This occurs because of contamination. This review presents information on animal farming in South Africa, the microbial and chemical contamination of meat, and the consequential effects on public health. In South Africa, the sales of meat can be operated both formally and informally. Meat becomes exposed to contamination with different categories of microbes, originating from varying sources during preparation, processing, packaging, storage, and serving to consumers. Apparently, meat harbours diverse pathogenic microorganisms and antibiotic residues alongside the occurrence of drug resistance in zoonotic pathogens, due to the improper use of antibiotics during farming. Different findings obtained across the country showed variations in prevalence of bacteria and multidrug-resistant bacteria studied, which could be explained by the differences in the manufacturer practices, handling processes from producers to consumers, and the success of the hygienic measures employed during production. Furthermore, variation in the socioeconomic and political factors and differences in bacterial strains, geographical area, time, climatic factors, etc. could be responsible for the discrepancy in the level of antibiotic resistance between the provinces. Bacteria identified in meat including Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, Campylobacter spp., Salmonella spp., etc. are incriminated as pathogenic agents causing serious infections in human and their drug-resistant counterparts can cause prolonged infection plus long hospital stays, increased mortality and morbidity as well as huge socioeconomic burden and even death. Therefore, uncooked meat or improperly cooked meat consumed by the population serves as a risk to human health.

Prevalence of Antimicrobial-resistant Bacteria in HACCP Facilities

Foodborne pathogens, such as Staphylococcus aureus and Salmonella spp., develop antimicrobial resistance (AMR) over time, resulting in compromised food safety. Therefore, this study aimed to determine the prevalence, compliance against Malaysia's veterinary standing procedure directive (APTVM 16 (c): 1/2011): Appendix 713), and antimicrobial resistance (AMR) profiles of S. aureus and Salmonella spp., in raw poultry meat, poultry meat products, and poultry-based ready-to-eat (RTE) foods. Here, 699 raw poultry meat and meat products samples were obtained from selected hazard analysis critical control points (HACCP)-certified poultry meat-processing plants. Additionally, 377 samples of poultry-based RTE meals were collected from dine-in establishments and hospital catering facilities in Klang Valley, Malaysia. Salmonella spp. and S. aureus were present in 2.1% and 2.8% of the analyzed samples, respectively. Salmonella spp isolated from raw poultry meat and its products displayed resistance to ampicillin (100%), chloramphenicol (87.0%), cefuroxime (60.9%), cefazolin (56.5%), and kanamycin (52.2%). Similarly, S. aureus isolated from raw poultry meat, its products, and poultry-based RTE foods exhibited resistance against tetracycline, chloramphenicol, penicillin, ciprofloxacin, trimethoprim, kanamycin, and cefoxitin. The multi-antibiotic resistance (MAR) demonstrated by these foodborne pathogens makes their prevalence disconcerting. This highlights the need for more stringent monitoring and enduring sanitary and hygiene practices in HACCP establishments to prevent foodborne infections and potential transmission of AMR bacteria.

The Challenge of Overcoming Antibiotic Resistance in Carbapenem-Resistant Gram-Negative Bacteria: "Attack on Titan"

The global burden of bacterial resistance remains one of the most serious public health concerns. Infections caused by multidrug-resistant (MDR) bacteria in critically ill patients require immediate empirical treatment, which may not only be ineffective due to the resistance of MDR bacteria to multiple classes of antibiotics, but may also contribute to the selection and spread of antimicrobial resistance. Both the WHO and the ECDC consider carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Pseudomonas aeruginosa (CRPA), and carbapenem-resistant Acinetobacter baumannii (CRAB) to be the highest priority. The ability to form biofilm and the acquisition of multiple drug resistance genes, in particular to carbapenems, have made these pathogens particularly difficult to treat. They are a growing cause of healthcare-associated infections and a significant threat to public health, associated with a high mortality rate. Moreover, co-colonization with these pathogens in critically ill patients was found to be a significant predictor for in-hospital mortality. Importantly, they have the potential to spread resistance using mobile genetic elements. Given the current situation, it is clear that finding new ways to combat antimicrobial resistance can no longer be delayed. The aim of this review was to evaluate the literature on how these pathogens contribute to the global burden of AMR. The review also highlights the importance of the rational use of antibiotics and the need to implement antimicrobial stewardship principles to prevent the transmission of drug-resistant organisms in healthcare settings. Finally, the review discusses the advantages and limitations of alternative therapies for the treatment of infections caused by these "titans" of antibiotic resistance.

Antimicrobial Resistance: A Growing Serious Threat for Global Public Health

Antibiotics are among the most important discoveries of the 20th century, having saved millions of lives from infectious diseases. Microbes have developed acquired antimicrobial resistance (AMR) to many drugs due to high selection pressure from increasing use and misuse of antibiotics over the years. The transmission and acquisition of AMR occur primarily via a human-human interface both within and outside of healthcare facilities. A huge number of interdependent factors related to healthcare and agriculture govern the development of AMR through various drug-resistance mechanisms. The emergence and spread of AMR from the unrestricted use of antimicrobials in livestock feed has been a major contributing factor. The prevalence of antimicrobial-resistant bacteria has attained an incongruous level worldwide and threatens global public health as a silent pandemic, necessitating urgent intervention. Therapeutic options of infections caused by antimicrobial-resistant bacteria are limited, resulting in significant morbidity and mortality with high financial impact. The paucity in discovery and supply of new novel antimicrobials to treat life-threatening infections by resistant pathogens stands in sharp contrast to demand. Immediate interventions to contain AMR include surveillance and monitoring, minimizing over-the-counter antibiotics and antibiotics in food animals, access to quality and affordable medicines, vaccines and diagnostics, and enforcement of legislation. An orchestrated collaborative action within and between multiple national and international organizations is required urgently, otherwise, a postantibiotic era can be a more real possibility than an apocalyptic fantasy for the 21st century. This narrative review highlights on this basis, mechanisms and factors in microbial resistance, and key strategies to combat antimicrobial resistance.

The Impact of a Phytobiotic Mixture on Broiler Chicken Health and Meat Safety

The purpose of the study was to assess the effects of different doses of a phytobiotic mixture on selected production parameters and meat quality and to assess the residue of the preparation in tissues and the possible toxic effects in broiler chickens. Broiler chicks aged 160 days, divided into four equal groups, were supplemented with the phytobiotic mixture at different doses, D1-0.5 mL/L, D2-1 mL/L, and D3-2 mL/L, four times during a 42-day trial. There were no statistically significant differences in weight gain per week of life and mortality in the birds. The study also demonstrated that the use of the mixture of phytobiotics had no significant effect on colour, pH, WHC, and natural leakage. However, a beneficial effect of the additive was found in the group treated with a dose of 1 mL/L, where less thermal leakage from the meat was demonstrated. Furthermore, significant differences in the change in thigh muscle tenderness were also observed. In the histopathological analysis of the liver no significant differences were observed. In addition, no residues of the mixture or its metabolites were found in the tissues analysed. In conclusion, the proposed scheme of administration of the phytobiotic additive, regardless of the dose, does not cause pathological changes in organs and does not carry the risk of residues of the product in tissues intended for human consumption.