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

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.

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.

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 host 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 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.

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.

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.

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.

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.

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.

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.

Prototype for rapid test devices to detect residues of sulfonamides in chicken carcasses from traditional breeders in Surabaya, Indonesia

Background and Aim

Sulfadiazine, one of the sulfonamide group's active compounds, is widely used for therapeutic production against several diseases. Veterinary drug residues can have a significant impact on human health conditions. This study aimed to develop a prototype of rapid test devices (RTDs) for detecting sulfadiazine residues on chicken carcasses based on the color indication.

Materials and Methods

Seven samples of carcasses collected from traditional breeders in Surabaya-Indonesia were prepared and tested using RTDs. This sample represents the population considering that in the last report, the use of antibiotics was more than 40%, while the ability to monitor RTDs was estimated at 100. The standard color of purple by Hex code standard color or decimal code color was used to compare the positive samples. A light-emitting diode (LED) lamp was used to observe purple color. Analysis of sulfonamides resulting from RTDs was compared using a ultraviolet-visible spectrophotometer.

Results

Sulfonamides contamination levels of 50% and 100% were detected at concentrations of 0.472 μg/mL and 0.642 μg/mL, respectively. Sulfonamides contamination that was <0.395 μg/mL did not appear purple.

Conclusion

The study's findings showed that RTDs can be used to detect sulfonamides residues at a limit of detection 0.5 mg/mL after a 45 min exposure to an LED operating at a wavelength of 980 nm (p < 0.05). The limitation of RTDs was not being able to monitor the presence of residues bound in fat samples. Rapid test devices can be developed for commonly monitoring devices due to the limited technology available in the market.

Bacteriostatic Effects of Yujin Powder and Its Components on Clinical Isolation of Multidrug-Resistant Avian Pathogenic Escherichia coli

Escherichia coli is one of the most common pathogenic bacteria in diarrheal chickens, leading to serious economic losses in the poultry industry. The limited effect of antibiotics on antibiotic-resistant E. coli makes this bacterium a potential threat to human health. Yujin powder (YJP) has been reported as an agent that releases the symptoms caused by E. coli for a long time. The objective of this study is to investigate the effect of Yujin powder (YJP) and its components, Scutellariae Radix (SR) and Baicalin (Bac), anti-against multi-drug-resistant E. coli in vitro and in vivo. A multi-drug-resistant bacteria was isolated and identified from a clinical diarrheal chick. Then, the anti-bacterial effects of drugs were assessed in vitro and in vivo by analyzing the bacteria loads of organs, the levels of endotoxin, TNF-α, IL-1β, and IL-6 of the serum. Results found that the pathogenic E. coli was resistant to 19 tested antibiotics. YJP, SR, and Bac could directly inhibit the growth of this strain at high concentrations in vitro, and presents obvious anti-bacterial effects by reducing the bacterial loads, the release of endotoxin, and inflammation in vivo, which was much more effective than the resistant antibiotic ciprofloxacin. This study demonstrates that those natural medicines have the potential to be used as novel treatments to treat the disease caused by this isolated MDREC strain.

Antibiotic Resistance and Food Safety: Perspectives on New Technologies and Molecules for Microbial Control in the Food Industry

Antibiotic resistance (ABR) has direct and indirect repercussions on public health and threatens to decrease the therapeutic effect of antibiotic treatments and lead to more infection-related deaths. There are several mechanisms by which ABR can be transferred from one microorganism to another. The risk of transfer is often related to environmental factors. The food supply chain offers conditions where ABR gene transfer can occur by multiple pathways, which generates concerns regarding food safety. This work reviews mechanisms involved in ABR gene transfer, potential transmission routes in the food supply chain, the prevalence of antibiotic residues in food and ABR organisms in processing lines and final products, and implications for public health. Finally, the paper will elaborate on the application of antimicrobial peptides as new alternatives to antibiotics that might countermeasure ABR and is compatible with current food trends.

Lebanese fermented goat milk products: From tradition to meta-omics

Ambriss, Serdaleh and Labneh El Darff are traditional Lebanese products made from fermented goat's milk. A questionnaire completed by 50 producers of these products showed that they are prepared by periodic percolation either by milk or by Laban in amphora or goat skins during the lactation season. Production is carried out on a small scale and in a limited number of production units, often by elderly people, resulting in a real risk of disappearance of these products and loss of the corresponding microbial resources. In this study, 34 samples from 18 producers were characterized by culture-dependent and -independent analyses. The results obtained from these two methods were radically different, the latter revealing in Ambriss and Serdaleh the co-dominance of Lactobacillus kefiranofaciens, a fastidious-growing species, and Lactococcus lactis in a viable but not culturable state. Overall, their composition is reminiscent of kefir grains. Phylogenomic and functional analyses of the genomes of the key species Lb. kefiranofaciens have revealed differences from those found in kefir, particularly in their polysaccharide genes, which may explain the absence of grains. However, Labneh El Darff displayed a dominance of Lactobacillus delbrueckii, probably due to the addition of Laban. In addition, the study identified several zoonotic pathogens, including Streptococcus parasuis, which dominated in one sample. Metagenome-Assembled Genome (MAG) analysis indicated that this pathogen acquired lactose utilization genes through horizontal gene transfer. The contamination of the herd with Mycoplasmopsis agalactiae in the Chouf region was also revealed by MAG analysis of the Serdaleh samples. Antibiotic resistance genes were detected in most of the samples, particularly in the Serdaleh ones, where the dominant L. lactis strains possessed a plasmid with a multi-resistance island. Finally, this study paves the way for further analyses to shed light on the resilience of these ecosystems established in amphora or in goatskins and to improve hygiene practices for milk production.

Research Progress on Lycopene in Swine and Poultry Nutrition: An Update

Oxidative stress and in-feed antibiotics restrictions have accelerated the development of natural, green, safe feed additives for swine and poultry diets. Lycopene has the greatest antioxidant potential among the carotenoids, due to its specific chemical structure. In the past decade, increasing attention has been paid to lycopene as a functional additive for swine and poultry feed. In this review, we systematically summarized the latest research progress on lycopene in swine and poultry nutrition during the past ten years (2013-2022). We primarily focused on the effects of lycopene on productivity, meat and egg quality, antioxidant function, immune function, lipid metabolism, and intestinal physiological functions. The output of this review highlights the crucial foundation of lycopene as a functional feed supplement for animal nutrition.

Evaluation of the efficacy of the antimicrobial peptide HJH-3 in chickens infected with Salmonella Pullorum

As a promising substitute for antibiotics, increasing attention has been given to the clinical application of antimicrobial peptides (AMPs). In this study, the mode of action of the HJH-3 against Salmonella Pullorum was investigated. The structure and properties of HJH-3 were examined in silico, and minimum inhibitory concentrations (MICs) were determined to evaluate its antimicrobial spectrum. The time-kill kinetics of HJH-3 was determined. The hemolytic activity of HJH-3 was determined by measuring the hemoglobin ultraviolet absorption value, and the cytotoxicity was determined using a CCK-8 kit. The protective effect of HJH-3 on chickens infected with S. Pullorum was evaluated in vivo. The results demonstrated that HJH-3 exhibited strong antibacterial activity against Gram-negative pathogens at MIC values of 1.5625-25 μg/mL and against Gram-positive pathogens at MIC values of 25-50 μg/mL. HJH-3 also showed activity against the Candida albicans (100 μg/mL) and Bacillus subtilis (6.25-12.5 μg/mL). HJH-3 at 100 μg/mL completely killed S. Pullorum after co-incubation for 6 h. Likewise, the hemolysis rate of CRBCs treated with 100 μg/mL HJH-3 (7.31%) was lower than that of CRBCs treated with 100 μg/mL pexiganan (40.43%). Although the hemolysis rate of CRBCs treated with 400 μg/mL HJH-3 was increased to 13.37%, it was much lower than that of 400 μg/mL pexiganan (57.27%). In regards to cytotoxicity, HJH-3 had almost no-effect on the CEF proliferation, pexiganan decreased CEFs proliferation from 56.93 to 31.00% when increasing the concentration from 50 to 200 μg/mL. In a chicken infection model, the results showed that the antibiotic prevention and HJH-3 prevention groups exhibited the best treatment effect, with the chickens being protected from the lethal dose of S. Pullorum, a decreased number of bacteria in the blood and spleen, and less pathological changes in intestinal segments. The prevention of infection by HJH-3 was similar to that by Ampicillin; the effect of treatment after infection was lower than that of treatment before infection, and the survival rate of infected chicks treated with HJH-3 was 70%, which was still higher than that of the infected chickens. These results suggest that HJH-3 has good clinical application potential and can be used as a substitute for antibiotics for the prevention and treatment of S. Pullorum infection.

Current Landscape of Methods to Evaluate Antimicrobial Activity of Natural Extracts

Natural extracts have been and continue to be used to treat a wide range of medical conditions, from infectious diseases to cancer, based on their convenience and therapeutic potential. Natural products derived from microbes, plants, and animals offer a broad variety of molecules and chemical compounds. Natural products are not only one of the most important sources for innovative drug development for animal and human health, but they are also an inspiration for synthetic biology and chemistry scientists towards the discovery of new bioactive compounds and pharmaceuticals. This is particularly relevant in the current context, where antimicrobial resistance has risen as a global health problem. Thus, efforts are being directed toward studying natural compounds' chemical composition and bioactive potential to generate drugs with better efficacy and lower toxicity than existing molecules. Currently, a wide range of methodologies are used to analyze the in vitro activity of natural extracts to determine their suitability as antimicrobial agents. Despite traditional technologies being the most employed, technological advances have contributed to the implementation of methods able to circumvent issues related to analysis capacity, time, sensitivity, and reproducibility. This review produces an updated analysis of the conventional and current methods to evaluate the antimicrobial activity of natural compounds.

Microbial Resistance to Antibiotics and Biofilm Formation of Bacterial Isolates from Different Carp Species and Risk Assessment for Public Health

The aim of this research was to investigate the effects of biofilm on antibiotic resistance of the bacterial isolates present in fish meat and to assess the risk of antibiotic residues for public health. Common carp, silver carp and grass carp fishes were purchased from retail stores for an in vitro biofilm investigation and a drug-resistant pattern determination. In all samples, up to 10⁴ CFU/g of bacteria, such as Escherichia coli, Aeromonas hydrophila, Shewanella putrefaciens, Vibrio spp. and Staphylococcus spp., were observed. Isolates from the samples and their biofilms were subjected to an antibiogram assay using antibiotics such as amoxicillin, ampicillin, cefotaxime, ciprofloxacin, chloramphenicol, gentamicin, streptomycin, tetracycline and trimethoprim. Obtained results showed that some of the isolates were sensitive to antibiotics and some were resistant. Results of LC-MS/MS analysis showed that antibiotics residues were present in fish samples in the range between 4.9 and 199.4 µg/kg, with a total sum of 417.1 µg/kg. Estimated daily intake (EDI) was established to be 0.274 μg/kg of body weight/day for men and 0.332 μg/kg of body weight/day for women, with an acceptable daily intake (ADI) of 8.5 and 7.0 µg/kg of body weight/day for men and women, respectively. The results of the present study, therefore, highlight the safe consumption of fresh fish.

Antibiotic-Resistant Bacteria, Antimicrobial Resistance Genes, and Antibiotic Residue in Food from Animal Sources: One Health Food Safety Concern

Antibiotic-resistant bacteria causing foodborne serious illnesses can be found in contaminated food. Therefore, this study aimed to identify the pathogens, genes, and antimicrobial residues present in raw milk and meat. We collected 40 raw milk and 40 beef samples using the aseptic method from various parts of the Faisalabad metropolis, Pakistan. The samples were cultured on blood, MacConkey, and UTI chrome agar. The VITEK 2 compact system was used for microbial identification and determination of minimum inhibitory concentrations. Antimicrobial resistance genes for extended-spectrum β-lactamases, methicillin resistance in Staphylococcus aureus, and carbapenem resistance were identified using molecular techniques. ELISA was used to determine the tetracycline residue level in each sample. The beef samples showed polymicrobial contamination with 64 bacterial isolates, with Escherichia coli (29; 45.3%) and Klebsiella pneumoniae (11; 17.1%) predominating. The milk samples showed polymicrobial contamination with 73 bacterial isolates, with E. coli (22; 30%), K. pneumoniae (12; 16.4%), and S. aureus (10; 13.6%) forming the majority. Twenty-eight (43.7%) isolates from beef harbored tet genes, nineteen (29.6%) bla_CTX-M, and fourteen (21.8%) bla_NDM-1, and twenty-six (35.6%) isolates from milk harbored tet genes, nineteen (26%) bla_TEM and bla_CTX-M, and three (4%) bla_NDM-1. Twenty-two (55%) each of the beef and milk samples exceeded the maximum residue limit for tetracycline. Polymicrobial contamination by bacteria possessing bla_CTX-M, bla_TEM, bla_NDM-1, bla_OXA, mecA, and tet genes was identified in food samples. The high tetracycline residue levels pose a serious health risk to consumers.

Microbiological and chemical evaluation of dairy products commercialized in the Lebanese market

Background and Aim

Cheese is considered an essential component of the Lebanese table, however, several foodborne illnesses have been reported due to cheese consumption. This study aimed to assess the microbiological quality and the occurrence of antibiotic and pesticide residues in two traditional Lebanese cheeses, Akkawi and Baladiyeh. In addition, drug resistance of isolated pathogens from the cheese samples was evaluated.

Materials and Methods

Fifty Akkawi and Baladiyeh cheese samples were obtained in duplicate from 37 different commercial brands in supermarkets and shops from various regions of Lebanon. Samples of different weights were either individually vacuum packed or soaked in brine unpacked where it was placed in plastic bag after being purchased. Samples were homogenized to determine antibiotic and pesticide residues using liquid and gas chromatography coupled to mass spectrometry, and microbiological evaluation was performed according to the International Organization for Standardization reference analytical methods. The disk diffusion method was used to determine the susceptibility of these isolates to antibiotics.

Results

Microbiologically, 17% of Akkawi and 14% of Baladiyeh samples were found to be non-conforming. The bacterial isolates (n = 29) were tested for their susceptibility to 11 different antibiotics commonly prescribed in the Lebanese community or used for treating infections caused by Gram-negative bacteria and listeriosis. Each isolate was found to be resistant to at least three antibiotics. Liquid and gas chromatography coupled to mass spectroscopy analysis showed the absence of pesticide residues in all samples. However, sulfamethazine antibiotic residue was found in 14% of the samples.

Conclusion

The results suggest that the cheese samples tested could cause foodborne illnesses due to the detection of pathogenic bacteria and are a public health concern due to the presence of antibiotic residues and the transmission of multidrug-resistant organisms.

Impact of Anthropogenic Activities on the Dissemination of ARGs in the Environment-A Review

Over the past few decades, due to the excessive consumption of drugs in human and veterinary medicine, the antimicrobial resistance (AR) of microorganisms has risen considerably across the world, and this trend is predicted to intensify. Many worrying research results indicate the occurrence of pools of AR, both directly related to human activity and environmental factors. The increase of AR in the natural environment is mainly associated with the anthropogenic activity. The dissemination of AR is significantly stimulated by the operation of municipal facilities, such as wastewater treatment plants (WWTPs) or landfills, as well as biogas plants, agriculture and farming practices, including animal production and land application of manure. These activities entail a risk to public health by spreading bacteria resistant to antimicrobial products (ARB) and antibiotic resistance genes (ARGs). Furthermore, subinhibitory concentrations of antimicrobial substances additionally predispose microbial consortia and resistomes to changes in particular environments that are permeated by these micropollutants. The current state of knowledge on the fate of ARGs, their dissemination and the complexity of the AR phenomenon in relation to anthropogenic activity is inadequate. This review summarizes the state-of-the-art knowledge on AR in the environment, in particular focusing on AR spread in an anthropogenically altered environment and related environmental consequences.

Exposure to Veterinary Antibiotics via Food Chain Disrupts Gut Microbiota and Drives Increased Escherichia coli Virulence and Drug Resistance in Young Adults

Exposure to veterinary antibiotics (VAs) and preferred as veterinary antibiotics (PVAs) via the food chain is unavoidable for their extensive use not only for treating bacterial infections, but also for use as growth promoters in livestock and aquaculture. One of the consequences is the disturbance of gut microbiota. However, its impact on the virulence and drug resistance of opportunistic pathogens is still unclear. In this study, a total of 26 antibiotics were detected in the urine of 300 young undergraduates in Anhui Province. We found that excessive intake of milk was positively correlated to high levels of VAs and PVAs. It led to the dysbiosis of gut microbiota characterized by high abundance of Bacteroidetes and Proteobacteria. The increase in Proteobacteria was mainly due to a single operational taxonomic unit (OTU) of Escherichia coli (E. coli). We isolated several E. coli strains from participants and compared their drug resistance and virulence using PCR assay and virulence-related assays. We observed that exposure to high levels of VAs and PVAs induced more resistant genes and drove E. coli strain to become more virulent. At last, we conducted transcriptome analysis to investigate the molecular mechanism of virulent and drug-resistant regulators in the highly virulent E. coli strain. We noted that there were multiple pathways involved in the drug resistance and virulence of the highly virulent strain. Our results demonstrated that participants with high-level VAs and PVAs exposure have a disrupted gut microbiota following the appearance of highly drug-resistant and virulent E. coli and, therefore may be at elevated risk for long-term health complications.