Correlation between veterinary antimicrobial use and antimicrobial resistance in food-producing animals: a report on seven countries

Situational analysis of human and agricultural health practice: One Health and antibiotic use in an indigenous village in rural Punjab, India

Antimicrobial resistance (AMR) represents one of the biggest threats to health globally. The rise of AMR has been largely attributed to the misuse and abuse of antimicrobials in veterinary, human, and agricultural medicine. This study aimed to assess human, livestock, and agricultural health profiles, and practices of One Health and antibiotic use through a situational analysis of an Indigenous village Gurah, in a rural area of Mohali district in Punjab state using a demographic and facility survey. A survey questionnaire was used to collect information on the village's socio-demographic, human, livestock, and agricultural profiles. The study included 77 households from the village Gurah, with the majority i.e., 71.4 % engaged in agricultural activity and 68.8 % with livestock. Survey results showed that self-reported adherence to any medicine prescribed by doctors was high (92.3 %) and self-medication reported by the respondents was 11 %. Forty-two percent of antibiotic consumption was verified from prescription. The major crops grown in the village were exposed to pesticides, and most dairy and non-dairy products were sold in markets, with consumers unaware of any pesticide or antibiotic exposure. Additionally, villagers were unaware of disease diagnosis and the medicines their livestock consumed. Findings from veterinarians revealed that around 50 % of the livestock was given antibiotics for treatment for mastitis. In our study, 67.9 % of the green fodder for animals was homegrown and pesticide use was reported. The study reported that 81.1 % of the animal feed additives were purchased from the market and farmers might be unaware whether commercially-purchased feed contains antibiotics. The results provide a picture of the current situation and guide further research for the containment of AMR under the One Health approach. Inadequate multi-sectoral and cross-disciplinary efforts to combating AMR in current practice call for prompt coordinated action integral to a "One Health approach."

Knowledge, attitudes and practices of veterinarians and para-veterinarians towards antimicrobial stewardship in Malawi: underutilized strength in the fight against antimicrobial resistance

Antimicrobial resistance (AMR) is a global public health concern, and the inappropriate use of antibiotics in animals and humans is considered a significant contributing factor. Para-veterinarians and veterinarians are vital in the fight against AMR. The study aimed to evaluate the knowledge, attitudes and practices of the para-veterinarians and veterinarians towards antimicrobial stewardship in Malawi. A cross-sectional questionnaire survey among the para-veterinarians and veterinarians was conducted from October 2024 to January 2025. A total of 69 participants, comprised of 42 para-veterinarians and 27 veterinarians, participated in this study, and the response rate for the survey was 44% (n = 158). The study used a predetermined cutoff of ≥ 55% to classify scores as having good knowledge, good practice, and a positive attitude. The study found that 85.5% of the respondents had good knowledge and 98.6% had good practices towards antimicrobial stewardship and prevention of AMR, while 92.8% had favorable attitude towards AMR and antimicrobial stewardship. The maximum obtainable scores for each construct were 11, 13 and 13 for knowledge, practice, and attitude, respectively. The overall mean scores for knowledge, practice and attitude were 11.25 ± 2.83, 8.71 ± 1.34 and 9.04 ± 1.64, respectively. These findings indicated that the respondents had good knowledge, good practices and favorable positive attitude towards AMR and antimicrobial stewardship. The study concludes that there is good level of knowledge, practice and favorable attitude among para-veterinarians and veterinarians towards antimicrobial stewardship which can be capitalized in the fight against AMR in Malawi. The veterinary professionals can be entrusted to comply with responsible antimicrobial prescriptions and use.

High prevalence of low-concentration antimicrobial residues in commercial fish: A public health concern in Bangladesh

Antibiotics are widely used in commercial fish farms in Bangladesh for therapeutic and prophylactic purpose, raising concerns about antimicrobial resistance (AMR) and environmental contamination. This study used Thin Layer Chromatography to detect antimicrobial residues in four commercially available fish species- Tilapia (Oreochromis aureus), Stinging catfish (Heteropneustes fossilis), Climbing perch (Anabas testudineus), and Pabda (Ompok pabda)-with 100 samples per species. Ultra High-Performance Liquid Chromatography quantified residues in a subset of 25 samples per species. The prevalence of Ciprofloxacin, Oxytetracycline, and Chlortetracycline residues varied significantly among fish species, with the highest prevalence observed for Ciprofloxacin in Tilapia (42%), Oxytetracycline in Pabda (41%), and Chlortetracycline in Tilapia (49%). Additionally, the prevalence of Levofloxacin and Chlortetracycline differed by sampling location, with the highest levels found in Jhawtala market, 27.5% for Levofloxacin and 53.8% for Chlortetracycline. Furthermore, residue concentrations were highest for Enrofloxacin in Climbing perch (69.32 µg/Kg) and Oxytetracycline in Pabda (88.73 µg/Kg). The highest Hazard Quotient (HQ) was for Enrofloxacin in Climbing perch (0.480), followed by Pabda (0.460), Stinging catfish (0.420), and Tilapia (0.387). While the HQ values were below 1.0, indicating no immediate toxicological risk, residues raise public health concerns due to the chance of potential AMR development. Further research is needed on antimicrobial bioaccumulation, indirect exposure sources, environmental contamination, and antimicrobial resistance in aquaculture and wild fish.

Growth, Carcass Traits, Blood Chemistry and Gut Microbiota in Broiler Chickens Fed Diets Enriched With Garden Cress Seed Powder as a Natural Growth Enhancer

This study investigated the effects of garden cress seed powder (GCSP) as a natural growth promoter and antioxidant agent in broiler diets, focusing on growth performance, carcass characteristics, microbial load and blood traits. A total of 210 1-day-old Arbor Acres broiler chicks were assigned to 3 experimental groups in a completely randomized design. Each group consisted of 7 replicates with 10 unsexed chicks per replicate. The dietary treatments included: (A) a basal diet without additives (control); (GCSP 1) a basal diet supplemented with 1 g GCSP/kg diet and (GCSP 2) a basal diet supplemented with 2 g GCSP/kg diet. The results revealed no significant differences in body weight (BW), BW gain (BWG), feed intake (FI) and feed conversion ratio (FCR) between the GCSP-treated groups and the control. However, numerically, the GCSP-supplemented groups exhibited improved BW, BWG and FCR compared to the control. Carcass traits remained largely unaffected, except for dressing percentage, carcass yield, thigh proportion and abdominal fat percentage, where significant differences were observed. Blood biochemical analysis showed a reduction in total protein, albumin and globulin levels in GCSP-fed groups, whereas high-density lipoprotein (HDL) levels increased and low-density lipoprotein (LDL) and very LDL (VLDL) levels decreased, though these changes were not statistically significant. Immunological and antioxidative responses improved, as evidenced by elevated immunoglobulin Y (IgY), immunoglobulin M (IgM) and superoxide dismutase (SOD) levels, alongside reduced malondialdehyde (MDA) levels in the GCSP-fed groups compared to the control. In conclusion, dietary supplementation with GCSP enhanced broiler immunity and antioxidative status, promoting increased IgY, IgM and SOD levels while reducing MDA levels. These findings highlight GCSP as a potential natural additive to improve broiler health and contribute to the production of healthier poultry products for consumers.

Improved pharmacotherapy after revised dosing regimens of two slow-release formulations of benzylpenicillin in an Actinobacillus pleuropneumoniae infection model in pigs

BACKGROUND

Actinobacillus pleuropneumoniae (APP) is a Gram-negative bacterium that causes respiratory disease in pigs, resulting in significant economic losses and reduced animal welfare. In Sweden, the drug of choice for treatment of APP infections is benzylpenicillin. However, limited pharmacokinetic and pharmacodynamic data for benzylpenicillin in pigs have led to variations in recommended dosing regimens. In this study, the impact of different dosing regimens and benzylpenicillin preparations on the progression of APP infection in pigs was investigated. Two experimental trials involving a total of 66 pigs were conducted. Pigs were intranasally inoculated with a pathogenic strain of APP serotype 2, and treatment was initiated upon the appearance of clinical signs. Two intramuscularly administered benzylpenicillin formulations, an aqueous and an oil-based suspension, were used with varying dosing regimens. The clinical outcome was assessed based on respiratory signs and rectal temperature measurements. Blood samples were collected for measuring white blood cell counts, serum antibody levels, and acute-phase protein concentrations. Necropsies were performed to evaluate lung lesions and to reisolate APP.

RESULTS

The results indicated that benzylpenicillin dosing regimens of 20-30 mg/kg administered every 12 h achieved larger benzylpenicillin plasma-exposure compared to the labelled dose of 10-30 mg/kg every 24 h. The oil-based suspension demonstrated superior efficacy compared to the aqueous suspension. Dosing regimens that maintain effective plasma concentrations of benzylpenicillin were shown to have better clinical outcomes as measured by reduced lung lesions at necropsy. Increased benzylpenicillin exposure was associated with a better ranking of overall treatment response.

CONCLUSIONS

Several dosing regimens that increased the plasma benzylpenicillin exposure were associated with better clinical success than the labelled doses. The findings support the treatment of APP-infected pigs with optimised benzylpenicillin dosing regimens. Optimising the use of existing antibiotics is crucial given the limited development of new antimicrobial agents and the need to combat antimicrobial resistance with regards to both human and animal health.

Biosecurity Implications, Transmission Routes and Modes of Economically Important Diseases in Domestic Fowl and Turkey

The poultry industry is a critical source of affordable protein worldwide; however, it faces continuous threats from various poultry diseases that significantly impact public health, economic stability, and food security. Knowledge of and examination of the transmission routes, risk factors, and environmental survival characteristics of the most important pathogens affecting poultry populations, as well as the importance of strict biosecurity, are pivotal. Transmission routes are split into direct and vector-borne pathways, and indirect ways, which include infections via contaminated surfaces and vector-borne pathways, including insects and rodents. Avian influenza virus and Newcastle disease virus spread through respiratory droplets, and their transmission risk increases with increasing stocking density. While other pathogens (e.g., infectious bursal disease virus and Salmonella spp.), to persist long-term in the environments, for example, feed and litter, increasing the probability to persist long-term in the environments, for example, feed and litter, increasing the probability of infection. The long-term resilience of pathogens in multiple pathogens in various environmental conditions highlights the role of biosecurity, sanitation, and hygiene controls in preventing disease outbreaks. High stocking density in production systems, suboptimal ventilation, and inadequate biosecurity controls further increase transmission risks. This paper summarizes important disease transmissions and reinforces the need for strict biosecurity protocols and routine health monitoring to prevent the spread of pathogens within and beyond poultry facilities. These strategies can support safe poultry production, address growing global demand, and ensure food safety and public health.

Whole genome sequencing of non-aureus Staphylococcus species from poultry barn bioaerosols across Alberta reveals circulation of isolates with multiple antibiotic resistant genes and disinfectant resistant genes

OBJECTIVES

Poultry environment has vast variety of bacterial species and non-aureus Staphylococcus species (NASS) are predominantly found. Various NASS are normal inhabitant of gastrointestinal tract and skin of chickens. The study objective was to isolate and identify NASS from bioaerosols of layer chicken barns across Alberta, leading to the phenotypic and genotypic antimicrobial resistance (AMR) profiling of the isolated bacterial colonies.

METHODS

A total of 15 barns were sampled in this study with an XMX-CV microbial air sampler. Phenotypic AMR profiles were determined using the Sensititre® broth microdilution method on the standard CMV3AGPF plates and whole genome sequencing (WGS) was conducted to confirm the species and AMR genes.

RESULTS

Seven Staphylococcus equorum, 5 Staphylococcus shinii, 1 Staphylococcus pseudoxylosus, 1 Staphylococcus cohnii, and 1 Staphylococcus gallinarum isolates were confirmed and identified by WGS and comparative genomic analysis. One of the S. equorum isolate was genetically highly divergent from the remaining isolates of the study. The phenotypic susceptibility profile showed 73.3% (11/15) of the isolates were resistant to lincomycin, 66.7% (10/15) were resistant to tetracycline, 33.3% (5/15) were resistant to streptomycin, 20% (3/15) were resistant to erythromycin, and 6.3% were resistant to gentamicin. A total of 10 antimicrobial resistance genes (ARGs) for antibiotics and 1 gene encoding resistance to disinfectants were detected among the study isolates by WGS.

CONCLUSIONS

Normal bioaerosol microflora having ARGs may lead to reduced therapeutic effectiveness of antibiotics in poultry and these ARGs can be a source of serious public health concern.

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.

Distribution, lipophilicity and tissue half-life as key factors in sulphonamide clearance from porcine tissues

Introduction

Sulphonamides are some of the most widely used antimicrobial drugs in the treatment of bacterial diseases in pigs. The study was conducted to compare the total exposure of tissue to a group of active substances in a single formulation and evaluate the impact of the volume of distribution, lipophilicity and tissue half-life of sulfadimethoxine, sulphathiazole, sulphamethazine and sulphacetamide in two different veterinary drug formulations - Polisulfalent, which was preparation A, and Polisulfamid, which was preparation B.

Material and Methods

Each tested therapeutic preparation was administered to 15 piglets of the Polish Landrace breed. To assume general exposure expressed as the sum of all observed concentrations of all active substances, semi-log regression analyses were performed for both formulations.

Results

The estimated tissue half-life was 21.19 h for preparation A and 17.36 h for preparation B. The comparison of the semi-log regression parameters shows that formulation B's Y-intercept and slope values were higher than formulation A's. The upper-bound CI for the Y-intercept and slope value of formulation B was higher than those of formulation A, at 38.7 and 20.8%, respectively.The lower-bound CI for the Y-intercept and slope value of formulation B was also higher than those of formulation A, at 20.6 and 42.9%, respectively.

Conclusion

Current observations lead to the conclusion that in late-stage drug elimination, it is not the blood half-life, but rather a drug's volume of distribution which is key in determining the clearance period, this volume being dependent on the physicochemical characteristics of the drug.

Effectiveness of a single-dose phage cocktail on the reduction of multidrug-resistant Escherichia coli in suckling piglets

Antibiotics are commonly used in pig farming to control infections caused by diarrhea-causing Escherichia coli (E. coli). However, improper or excessive use of antibiotics in pigs can enhance antibiotic resistance (ABR). This study used bacteriophage (phage) treatment to control ABR E. coli in diarrheal suckling piglets. Fifty E. coli isolates were previously isolated from suckling pigs, which showed resistance to amoxicillin (100 %), oxytetracycline and neomycin (94 %), sulfamethoxazole-trimethoprim (70 %), gentamicin (56 %), cephalexin (54 %), enrofloxacin (42 %), and colistin (28 %). Five phages (WPEC1, WPEC2, WPEC3, WPEC4, and WPEC5) were included in this study. These phages showed a diverse lytic profile ranging from 46.0 % to 64.0 % on the tested ABR E. coli isolates. The phage cocktail reduced the count of five representative E. coli by showing up to 8 log-units reduction (p < 0.05) after phage treatment for 6-24 h. From the in vivo study, a single dose of the phage cocktail (9 log PFU/mL) reduced the number of E. coli present in the gastrointestinal tract of suckling piglets by showing a 1.33 log-units reduction on day 7 (p < 0.05). In addition, the fecal score of the phage treatment group was lower than that of the control group (p < 0.05). However, body weight gain (BWG) and average daily gain (ADG) were not significantly different in both groups (p > 0.05). These findings suggest that a developed phage cocktail could be used as a potential biocontrol to fight ABR E. coli, reduce the chance of piglet mortality, and increase safety during pig production.

Dietary supplementation of microbiota inoculum and single clove garlic extract on growth performance, egg quality, reproductive organ, and hematological trait in laying quail

Background

Several alternative feed additives to replace AGP to maintain good quail performance include the use of probiotics and herbal extracts.

Aim

In this study, the researchers want to find out the best dosage of microbiota inoculum as probiotics (Lactobacillus acidophilus, Bifidobacterium, and Lactobacillus plantarum), single garlic extract (Allium Sativum L), and combination groups to improve laying quail egg production, hematology profile (erythrocytes, hemoglobin, hematocrit, leukocytes, and platelets), and reproductive organs in terms of length and weight and have better egg quality on the internal (Haugh units, yolk score, albumin index, yolk index) and external (shell thickness, egg weight) while laying phase of laying quail.

Methods

A total of 100 4-week-old laying quails of uniform body weight were randomly distributed into five treatments with four replicates each and five quails in each replicate. There were 5 treatment groups: T0 quails were given basal feed; T1 quails were given basal feed and drinking water added with probiotics at a dose of 4 ml/l; T2 quails were given feed added with a single garlic extract at a dose of 2 ml/g and ordinary drinking water; T3 quails were given feed with a single garlic extract at a dose of 2 ml/g and drinking water supplemented with probiotics at a dose of 4 ml/l; and T4 quails were given a single garlic extract at a dose of 1 ml/g and drinking water supplemented with probiotics at a dose of 2 ml/l. The study investigated the effects of microbiota inoculum, including probiotics, garlic extract, and a control group, on reproductive organ morphologies in chickens. Results showed significant improvements in weight vagina, uterus, oviduct, ovarium, weight cloaca, growth performance, body weight, egg production, internal egg quality, yolk color score, yolk index, albumin index, external egg quality, Haugh unit, egg height, shape index, egg cell weight, and egg cell thickness.

Results

The number of erythrocytes was significantly higher in the chickens treated with the microbiota inoculum compared to the control group. Hemoglobin levels were not significant in all treatments, but hematocrit levels were significant in the chickens treated with the microbiota inoculum. Leukocytes were also significantly higher in the chickens treated with the microbiota inoculum compared to the control group.

Conclusion

The use of a combination of microbiota inoculum in drinking water and garlic extract in feed has been proven to be effective in reducing feed consumption, maintaining hematology, increasing reproductive organs, and boosting the number of laying quail productions, thereby reducing feed conversion ratio.

Cultured Bacteria in the Abdominal Wall Incision During the Realisation of Caesarean Section in Cows: A Preliminary Study

Although caesarean section (CS) is a common surgery, the bacteria contaminating the abdominal incision during this operation are not documented. This study aimed to enhance perioperative antibiotic therapy and reduce post-operative surgical site infections by describing the bacteria contaminating the abdominal incision during CS. Bacterial culture was performed on swabs sampled from the abdominal incision (muscular layers) of 23 cows during the realisation of CS. Bacteriology was positive in 6/22 samples. while 16/22 were negative (p = 0.03), and one sample was contaminated. All identified bacteria were aerobic, and 8/14 isolates were Gram-positive and 6/14 were Gram-negative (p = 0.7). The most encountered species were Acinetobacter spp., Aerococcus viridans, Neisseria spp. and Streptococcus spp.; other species were isolated only once. The abdominal incision of elective CS can be contaminated by ubiquitous aerobic Gram-positive and Gram-negative species coming from the environment. This contamination might be avoided by using a better aseptic protocol and by improving the conditions in which CSs are performed. However, more samples are required, and antibiotic susceptibility determination is needed to identify the adequate pre-operative antibiotic.

Temporal trends in biosecurity in Irish pig herds using a standardized scoring system

BACKGROUND

Biosecurity measures are crucial to the introduction and spread of pathogens both within and between farms. External biosecurity focuses on preventing pathogens from entering or leaving the farm, while internal biosecurity aims to limit or stop the spread of pathogens within the farm. Implementing biosecurity measures not only protects animals from disease but also has positive effects on productivity, welfare and farm profitability. By reducing the need for antimicrobials, biosecurity measures also contribute to combating antimicrobial resistance. To assess and improve biosecurity, tools like Biocheck.UGent have been developed. In Ireland, the Biocheck.UGent tool has been widely used in pig farms since 2018. The aims of this study were firstly to assess temporal trends on biosecurity scores in Irish pig farms from 2018 to 2023 using the Biocheck.UGent tool and secondly to identify areas for improvement.

RESULTS

There was an increase in the number of annual assessments over the study period, with the majority of farms being assessed multiple times. Overall, external biosecurity scores were higher than internal scores. Improvements in the scores were observed over time for most of the subcategories for external and internal biosecurity and across the different farm types. Analysis of the subcategories within the scoring system revealed areas with lower scores, including disease management, cleaning and disinfection, and measures between compartments. Weaner-to-finisher farms tended to have lower scores compared to other farm types.

CONCLUSIONS

While external biosecurity in Irish pig farms is generally high, there is room for improvement in internal biosecurity. This study highlights the importance of continuous efforts to improve biosecurity. The data obtained will aid in estimating the cost-benefit of implementing biosecurity measures, crucial for decision-making and better returns on investments.

Antimicrobial use in animal farms in Egypt: rates, patterns, and determinants

BACKGROUND

While antimicrobial use (AMU) in human healthcare has received significant attention as a key driver of antimicrobial resistance (AMR), less emphasis has been placed on AMU practices and attitudes in animal husbandry. To address this gap, this study examines the patterns and underlying drivers of AMU on animal farms.

METHODS

A survey instrument was distributed to farm staff in 150 animal farms across 15 Egyptian governorates. Farms were selected from a list curated by a private platform specialized in Egypt's poultry and cattle industry. An online search was conducted to identify additional farms not included in the list or when the contact information was unavailable. The instrument covered key items related to AMU including types of antimicrobials used, indications, their perceived benefits, and the feed conversion ratio (FCR). Using the theory of reasoned action (TRA) as a guiding theoretical framework, this study assesses key factors influencing the AMU behavior of farm personnel.

RESULTS

Out of 150 farm personnel invited to fill out the survey forms, 111 (74%) responded and agreed to participate. All surveyed personnel reported using antimicrobials, and almost two-thirds (65%) reported using them for non-therapeutic purposes. Non-therapeutic use of antimicrobials, however, had no impact on FCR across all farm types (poultry, cattle, and mixed). The most used antimicrobials were penicillins (81%), followed by macrolides (78%) and tetracyclines (72%). Half of the studied farms reported using colistin, with more than half of this segment (55%) reporting using it for non-therapeutic purposes. Farm personnel's AMU behavior was associated with the TRA constructs: perceived benefits of antimicrobials (attitude) and perceived AMU behavior in other farms (subjective norm).

CONCLUSIONS

Antimicrobials are unanimously used in animal farms in Egypt, including those classified as last-resort options, such as colistin. Using antimicrobials for disease prevention or growth promotion did not decrease the FCR. Interventions that target the farm personnel's attitude and the subjective norm should be carried out to change their behavior regarding the use of antimicrobials. Egyptian guidelines for AMU in livestock are urgently needed, along with training to raise awareness of AMR and safer practices. The use of last-resort drugs like colistin should be banned in animal farming, and national surveillance systems should monitor AMU and AMR trends.

Making sense of sentinels: wildlife as the One Health bridge for environmental antimicrobial resistance surveillance

Antimicrobial resistance (AMR), arising from decades of imprudent anthropogenic use of antimicrobials in healthcare and agriculture, is considered one of the greatest One Health crises facing healthcare globally. Antimicrobial pollutants released from human-associated sources are intensifying resistance evolution in the environment. Due to various ecological factors, wildlife interact with these polluted ecosystems, acquiring resistant bacteria and genes. Although wildlife are recognized reservoirs and disseminators of AMR in the environment, current AMR surveillance systems still primarily focus on clinical and agricultural settings, neglecting this environmental dimension. Wildlife can serve as valuable sentinels of AMR in the environment, reflecting ecosystem health, and the effectiveness of mitigation strategies. This review explores knowledge gaps surrounding the ecological factors influencing AMR acquisition and dissemination in wildlife, and highlights limitations in current surveillance systems and policy instruments that do not sufficiently address the environmental component of AMR. We discuss the underutilized opportunity of using wildlife as sentinel species in a holistic, One Health-centred AMR surveillance system. By better integrating wildlife into systematic AMR surveillance and policy, and leveraging advances in high-throughput technologies, we can track and predict resistance evolution, assess the ecological impacts, and better understand the complex dynamics of environmental transmission of AMR across ecosystems.

Comparative metagenomics reveals limited differences in antimicrobial resistance gene abundance across conventional and natural livestock production systems

The livestock industry has been a source of concern in terms of antimicrobial resistance (AMR) development and spread, especially from a One Health perspective. Raising livestock without antimicrobials, so called natural (NAT) production, is an increasingly popular practice. This study used metagenomics to compare this practice to conventional (CONV) antimicrobial use (AMU) on the microbiome and resistome in the feces of beef cattle and swine and the cecal contents of broiler chickens. In cattle, Bacteroidetes, Euryarchaeota, and Spirochaetes were more abundant (q < 0.01) in CONV than NAT systems, with no differences (q > 0.05) in bacterial profiles in either swine or chickens. Classes of antimicrobial resistant genes (ARG) were not impacted regardless of AMU in any of the livestock species. However, many tetracycline resistance genes were more abundant in CONV as compared to NAT swine (q < 0.05), but this difference was not observed in cattle or chickens. This study confirmed that elimination of AMU does not necessarily result in an immediate decline in the abundance or diversity of ARGs within a single livestock production cycle.

The correlation between on-farm biosecurity and animal welfare indices in large-scale turkey production

This research aimed to determine the association between biosecurity and animal welfare measures in large-scale fattening turkey farms in Hungary. Large-scale farms raising male fattening turkeys across Hungary were contacted, with 24 agreeing to participate. The Biocheck.UGent questionnaire was used to evaluate biosecurity measures, and Animal Welfare Indicators (AWIN) protocol was used for welfare assessment. The association between biosecurity and welfare indicators was investigated by correlation testing and prediction accuracy using random forest classification. The areas of biosecurity that were shown to be closely linked to the welfare index were the organization of the farm (farm management, supply of materials), the control and hygienic measures implemented between farm structures, cleaning and disinfection measures on the farm, and control and hygienic measures implemented in the case of farm workers and visitors upon entrance and exit. The study highlighted the link between biosecurity and animal welfare in turkey production, concluding that enhanced biosecurity measures correlate with better welfare outcomes and emphasizing the need for comprehensive and well-implemented biosecurity protocols.

The efficacy of Artichoke leaf extract conjugated with organic zinc nanoparticles on growth, carcass traits and blood biochemical parameters of broilers

This study aimed to discover how using nano artichoke leaf extract Stabilized with zinc Nanoparticles (ZnO-Nano-ALPE) as an alternative to antibiotics and an antioxidant in broiler feed affected their growth, meat quality, and blood. In a completely randomized design experiment, 210 1-day-old chicks (Arbor Acres) were assigned to three trial groups. Each group was subdivided into seven replicates, each with ten unsexed chicks. The groups formed were as follows: the control group received a basal diet without additives. In contrast, the ZnO-Nano-ALPE1 and ZnO-Nano-ALPE2 groups received a basal diet plus 1.0 and 2.0 cm3 of nano artichoke leaf extract ZnO-Nano-ALPE /kg diet, respectively. The results showed significant changes in LBW on days 28 and 31 of their lives, with the ZnO-Nano-ALPE groups showing the greatest changes. Variation analysis revealed no discernible changes between the treatment groups; however, there were notable variations in the calculated feed intake (FI) on days 29 and 31. There were no notable variations in carcass features between treatments, except for the percentage of carcass, dressing, thigh, heart, and intestine cecum in the control group. In addition, we found significant differences in total protein, albumin, and globulin levels between treatments, with the control group showing higher levels compared to the other two groups. The diet increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and elevated cholesterol levels. The study revealed significant differences in immunoglobulins, Superoxide dismutase (SOD) and Malondialdehyde (MDA) levels among the treatments, with the 1.0 cm3 treatment group exhibiting the highest levels. Thus, adding ZnO-Nano-ALPE to growing chick feeds at 1.0 and 2.0 cm3 rates could improve productivity, some carcass characteristics, and blood parameters.

Phage diversity in One Health

One Health aims to bring together human, animal, and environmental research to achieve optimal health for all. Bacteriophages (phages) are viruses that kill bacteria and their utilisation as biocontrol agents in the environment and as therapeutics for animal and human medicine will aid in the achievement of One Health objectives. Here, we assess the diversity of phages used in One Health in the last 5 years and place them in the context of global phage diversity. Our review shows that 98% of phages applied in One Health belong to the class Caudoviricetes, compared to 85% of sequenced phages belonging to this class. Only three RNA phages from the realm Riboviria have been used in environmental biocontrol and human therapy to date. This emphasises the lack in diversity of phages used commercially and for phage therapy, which may be due to biases in the methods used to both isolate phages and select them for applications. The future of phages as biocontrol agents and therapeutics will depend on the ability to isolate genetically novel dsDNA phages, as well as in improving efforts to isolate ssDNA and RNA phages, as their potential is currently undervalued. Phages have the potential to reduce the burden of antimicrobial resistance, however, we are underutilising the vast diversity of phages present in nature. More research into phage genomics and alternative culture methods is required to fully understand the complex relationships between phages, their hosts, and other organisms in the environment to achieve optimal health for all.

Antimicrobial Use in the Animal Sector in Japan from 2011 to 2022

Background/Objectives: Evaluating antimicrobial use (AMU) is essential in the investigation and implementation of antimicrobial resistance (AMR) prevention measures. Here, we examined AMU using an index (mg/kg biomass) that considers the antimicrobial sales volume and livestock biomass in Japan from 2011 to 2022. Methods: Antimicrobial sales volumes were obtained from JVARM data, and biomass data were obtained from reliable statistics. Beef cattle, dairy cattle, pigs, broiler chickens, layer chickens, fish raised in freshwater, and fish raised in seawater were targeted in this study. Results: Tetracycline accounted for 39%, macrolides for 18%, penicillins for 12%, and sulfonamides for 11% of the sales in 2022. The peak antimicrobial sales volume was 847 tons in 2017, and then declined to 766 tons by 2022 with fluctuations in the interim. From the perspective of mg/kg biomass, AMU tended to increase in beef cattle, dairy cattle, and fish raised in seawater, while pigs, broilers, layers, and fish raised in freshwater showed a decreasing trend. In broilers, the decreasing trend that could not be confirmed by sales amount alone was detected using the newly established index. Conclusions: By calculating the mg/kg biomass, it became possible to create an interpretation that is different from that of the simple sales quantity data. We believe that this indicator is stable, transparent, and easily understandable for national monitoring.

Antimicrobial Usage and Antimicrobial Resistance in Commensal Escherichia coli from Broiler Farms: A Farm-Level Analysis in West Java, Indonesia

Background/Objectives: Antimicrobial resistance (AMR) is a global public health threat, with antimicrobial use (AMU) in livestock recognized as a significant driver. This study examines farm-level AMU and AMR as well as the relationship between AMU and AMR on broiler farms in Indonesia. Methods: Data were collected from 19 farms in West Java between 2019 and 2021 to examine AMU in depth across four to five successive production cycles. The correlation between AMU and AMR in commensal Escherichia coli (E. coli) was investigated. AMU was recorded as treatment days per 30-day production cycle, and antimicrobial susceptibility was assessed using epidemiological cut-off (ECOFF) values to differentiate wildtype (WT) and non-wildtype (NWT) E. coli. Results: The average AMU was 12 treatment days per 30-day production cycle, with a wide range of 4 to 22 days. On average, E. coli isolates from each farm exhibited NWT phenotypes, reflecting AMR levels, for 6 out of 14 antimicrobials tested. This included notable levels for the highest priority critically important antimicrobials (HPCIAs) ciprofloxacin (93%) and nalidixic acid (64%). A significant correlation (Spearman ρ = 0.67, p < 0.05) was observed between the total farm-level AMU and the number of antimicrobials for which NWT E. coli isolates were found. However, no significant correlation was found between AMU and AMR for the five most frequently used antimicrobials, likely due to a high baseline prevalence of NWT E. coli isolates and relatively few independent observations. Conclusions: These findings highlight the urgent need to reduce AMU in general, specifically the use of (HP)CIAs, to mitigate AMR on Indonesian broiler farms.

Quantification of Antimicrobial Use on Commercial Broiler Farms in Pakistan

Pakistan has a large, intensive broiler production industry, where antimicrobials are extensively used for both therapeutic and prophylactic purposes. Monitoring antimicrobial use (AMU) at the farm level is crucial to guide interventions for antimicrobial stewardship. The objective of this study was to comprehensively quantify AMU on commercial broiler farms in Pakistan using different metrics. Data on on-farm AMU (both therapeutic and prophylactic) were collected from intensive commercial broiler farms in Punjab, Pakistan. AMU was quantified using four different metrics: treatment incidence (TI) based on defined daily dose (TIDDDvetPK), TI based on defined course dose (TIDCDvetPK), TI based on used daily dose (TIUDDvetPK), and mg/kg biomass. The median TIDDDvetPK, TIDCDvetPK, TIUDDvetPK, and mg/kg biomass values were 57.7 (7.5-257.9), 13.3 (1.8-52.5), 75.3 (21.1-182.9), and 301 (46.8-1009.6), respectively, based on 741 group treatments given at 100 participating farms with 225 flocks. About 34% treatments were administered for therapeutic purposes, with 66% administered as prophylaxis. A total of 41 active substances, distributed across 17 antimicrobial classes, were identified from 139 commercial antimicrobial products used. The most commonly used active substances (AS), out of total 741 group treatments, were colistin (polymyxins) at 17%, enrofloxacin (quinolones) at 8%, neomycin (aminoglycosides) and amoxicillin (aminopenicillins) at 7% each, and procaine penicillin (NS penicillins) and streptomycin (aminoglycosides) at 6% each. According to the WHO categorization, 57% of the used AS were found to be critically important antimicrobials (CIAs) for human medicine. As many as 30% of treatments were administered in the first week (13% on the first day of production), and the main indication was prophylaxis for early chick mortality, followed by 21% in week 5, with main indication being feed supplements for necrotic enteritis. The average weight at slaughtering was 2.25 kg, gained after an average of 44 days of the production cycle. The alarmingly high AMU in Pakistani broiler production emphasizes the urgent need to reduce AMU, particularly involving CIAs and the prophylactic use of antimicrobials. This can be achieved by improving farm management practices and strengthening regulatory oversight to enable prudent antimicrobial use, eventually reducing the risk of AMR.

Positive impact of early-probiotic administration on performance parameters, intestinal health and microbiota populations in broiler chickens

Minimizing the utilization of antibiotics in animal production is crucial to prevent the emergence of antimicrobial resistances. Thus, research on alternatives is needed to maintain productivity, sustainability, and animal health. To gain a comprehensive understanding of probiotics' modes of action on performance, intestinal microbiota, and gut health in poultry, 3 probiotic strains (Enterococcus faecalis CV1028 [EntF], Bacteroides fragilis GP1764 [BacF], and Ligilactobacillus salivarius CTC2197 [LacS]) were tested in 2 in vivo trials. Trial 1 comprised of a negative control group fed basal diet (BD) and 3 treatment groups that received BD with EntF, BacF and LacS. Trial 2 included a negative control group, a positive control group with Zinc-Bacitracin as antibiotic growth promoter (AGP), and 2 groups treated with a blend of probiotics (EntF+BacF+LacS) during 0 to 10 or 0 to 35 d, respectively. Wheat-soybean-rye based diets without exogenous enzymes were used as a challenge model to induce intestinal mild- or moderate-inflammatory process in the gut. In Trial 1, individually administered probiotics improved FCR at 8 d compared to Control, but these positive effects were lost in the following growing periods probably due to the high grade of challenging diet and a too low dose of probiotics. In Trial 2, both Probiotic treatments, administered only 10 or 35 d, significantly improved FCR to the same extent as of the Antibiotic group at the end of the trial. Although the performance between antibiotic and probiotic mixture showed similar values, microbiota analysis revealed different microbial composition at 7 d, but not at 21 d. This suggests that modes of action of the AGP and the tested probiotic blend differ on their effects on microbiome, and that the changes observed during the first days' posthatch are relevant on performance at the end of the study. Therefore, the probiotics administration only during the first 10 d posthatch was proven sufficient to induce similar performance improvements to those observed in birds fed antibiotic growth promoters throughout the whole experimental trial.

How policy advocacy promotes regulated antibiotic use: Evidence from meat duck farmers of China

Antibiotic residues resulting from the misuse of veterinary antibiotics pose a serious threat to global food safety and the ecological environment. Regulating the use of antibiotics is currently a major concern; however, existing literature on this issue remains insufficient. Therefore, to advance research in this area, this study utilizes data from 988 questionnaires collected across 9 provinces in China and employs the 3SLS systematic estimation method. It constructs an analytical framework to explore the mechanisms through which policy advocacy (PA) influences regulating antibiotics use (RAU) among meat duck farmers. Specifically, the study examines two pathways: " PA - public opinion pressure perception (POPP) - RAU" and " PA - moral responsibility (MR) - RAU." Additionally, it explores the potential mechanisms through which PA impacts RAU among farmers. The results show that PA (Coef = 0.070, SE = 0.014) can promote RAU by increasing the level of POPP (Coef = 0.173, SE = 0.091). PA (Coef = 0.351, SE = 0.028) can also promote RAU by enhancing MR (Coef = 0.239, SE = 0.035). Meanwhile, this study introduces Internet use (IU) and reputational incentives (RI) as moderating variables to analyze their role in moderating the impact of PA on RAU. It was demonstrated that IU (Coef = 0.088, SE = 0.016) significantly enhances farmers' awareness of the value of RAU and amplifies the impact of PA on MR. However, IU (Coef = -0.017, SE = 0.008) was found to inhibit the effect of PA on POPP. RI fully satisfies farmers' need for " honor " and enhances the effectiveness of PA in promoting both POPP (Coef = 0.009, SE = 0.002) and MR (Coef = 0.058, SE = 0.004). Finally, the study proposes that the government expand PA channels, innovate methods, and combine online outreach with demonstrations to improve farmers' awareness of antibiotic use and address their reputational needs.

Awareness of Poultry Farmers of Interconnected Health Risks: A Cross-Sectional Study on Mycotoxins, Biosecurity, and Salmonellosis in Jimma, Ethiopia

Poultry farming in Ethiopia is crucial for food security and income, but it faces significant challenges due to gaps in farmer awareness. A cross-sectional study was conducted using the Biocheck.UGent™ biosecurity scoring system and a questionnaire to evaluate poultry farmers' basic and practical knowledge concerning salmonellosis and mycotoxins. The questionnaire revealed substantial gaps in basic and practical knowledge regarding Salmonella spp infections and mycotoxin among 38 poultry farmers in Jimma. About 68.4% of farmers were unaware of the impact of salmonellosis on both poultry and human health. Moreover, 78.9% had limited basic knowledge of how salmonellosis affects production and the economy. Farmers also showed limited practical knowledge of farm management and hygiene practices essential for preventing Salmonella spp. infections. Regarding mycotoxins, 63.2% of farmers lacked awareness of poultry feed management, 60.5% were unaware of the health risks mycotoxins pose, and 73.7% did not recognize signs of mycotoxin contamination. Although 55.3% of farmers demonstrated acceptable practical knowledge of strategies to reduce the impact of mycotoxin contaminations, there are still concerns, particularly since 65.8% and 55.3% only showed moderate practical knowledge of feed storage and mycotoxin prevention, respectively. The overall biosecurity scores of poultry farms were below the global average, with a score of 41.7 compared to the worldwide average of 64. The overall mean score for external biosecurity was 44.9, below the global average of 63. All 3 scoring platforms and biosecurity parameters indicated that internal biosecurity was the weakest aspect, with a score of 31.6, well below the global standard of 64. The results showed a weak correlation (rₛ = 0.06) between farmers' basic and practical knowledge scores about Salmonella spp. infections and mycotoxins. Similarly, there was a weak correlation between the poor biosecurity score of poultry farms and the basic and practical knowledge of poultry farmers on Salmonella spp. infections (rₛ = 0.17) and mycotoxins (rₛ = 0.25). In conclusion, the study found that poultry farmers in Jimma had poor basic and practical knowledge scores on Salmonella, mycotoxins, and biosecurity measures. Thus, awareness creation is paramount to improve these gaps to reduce the impact of mycotoxin contamination and poultry diseases and consequently to improve food security and food safety.

Prevalence and molecular characterization of ESBL-producing Escherichia coli isolated from broiler chicken and their respective farms environment in Malaysia

BACKGROUND

Extended spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) is an increasing public health threat. This study aimed to determine the prevalence and characterization of ESBL-producing Escherichia coli (E. coli) isolated from broiler chicken and their farm environment, in Kelantan Malaysia.

METHODS

Escherichia coli was isolated from 453 collected samples, including 210 cloacal swabs and 243 environmental samples. The antimicrobial susceptibility profile of the E. coli isolates was assessed for sixteen antibiotics using the disc diffusion method. The E. coli isolates were evaluated for phenotypic ESBL production using modified double disc synergy. After extraction of genomic DNA, ESBL resistance genes, phylogenetic group, and virulence genes were detected by PCR using appropriate primers. ESBL genes were further confirmed by sequencing. The molecular typing of E. coli strains was determined by Multilocus Sequence Typing (MLST).

RESULTS

A total of 93.8% (425/453) E. coli were isolated from the collected samples. Out of 334 E. coli isolates screened, 14.7% (49/334) were phenotypically ESBL producers. All the ESBL-EC were resistant to tetracycline, ciprofloxacin, and ampicillin. Thus, 100% of the ESBL-EC were multidrug resistant. Of the ESBL-EC 81.6% were positive for at least one ESBL encoding gene. The most prevalent ESBL gene detected was blaTEM (77.6%; 38/49) followed by blaCTX-M (32.7%; 16/49) and blaSHV (18.4%; 9/49). The majority of ESBL-EC belonged to phylogenic groups A followed by B1 accounting for 44.9% and 12.2%, respectively. The most frequently identified sequence types were ST10 (n = 3) and ST206 (n = 3). The most detected virulence genes in the E. coli isolates were astA (33.3%; 22/66) followed by iss (15.2%; 10/66).

CONCLUSIONS

Our results show both broiler chicken and their respective farms environment were reservoirs of multi-drug resistant ESBL-producing E. coli and ESBL resistance genes.

Prevalence, Antimicrobial Susceptibility, and Resistance Genes of Extended-Spectrum β-Lactamase-Producing Escherichia coli from Broilers Sold in Open Markets of Dakar, Senegal

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-Ec) poses a significant public health concern due to its widespread prevalence and resistance to multiple antibiotics. This study aimed to assess the prevalence, resistance profile, and carriage of ESBL-encoding genes in ESBL-Ec isolates from broilers in two markets of Dakar, Senegal. Sampling over a one-year period revealed that 61.7% of broilers carried ESBL-Ec in their cecum. Antibiotic susceptibility testing of 186 ESBL-Ec isolates showed high resistance to β-lactam antibiotics, including ampicillin, ticarcillin, and third-generation cephalosporins. Notably, all isolates were susceptible to imipenem. Multidrug resistance was frequent, with 91.4% of the isolates displaying this phenotype. Comparison between the two markets revealed variations in resistance to quinolones. PCR analysis detected blaCTX-M genes in all isolates, with blaCTX-M-1 being the most prevalent subgroup. Additionally, blaTEM and blaOXA genes were found in 26.3% and 2.7% of isolates, respectively, while no blaSHV genes were detected. Combinations of ESBL genes were common, with blaCTX-M15-blaTEM being the most frequent. These findings highlight the widespread prevalence of ESBL-Ec in broilers from Dakar markets, indicating a potential risk of transmission to humans through the food chain. Effective surveillance and intervention strategies are crucial to mitigate the spread of antimicrobial resistance in humans and animals.

Assessing veterinarians' opinions of antimicrobial stewardship initiative acceptability for farm practice in Wales

BACKGROUND

Antimicrobial stewardship (AMS) initiatives are imperative to safeguard antimicrobials and reduce resistance. Across the UK, AMS relies in part on the self-regulation of the veterinary profession, particularly in farm animal practice, alongside voluntary schemes and quality assurance systems. In Europe, AMS initiatives are often statutory and require responsibility from several sectors. Consideration of broader AMS initiatives, potentially unfamiliar to the Welsh veterinary profession, could optimise future policy and align it with the requirements of Welsh veterinarians.

METHODS

AMS initiatives were collated from nations with long-standing low antimicrobial use. A survey was constructed permitting veterinarians' evaluation of initiative feasibility and effectiveness (collectively, 'acceptability') within Welsh farm animal practice.

RESULTS

Veterinarian-directed AMS initiatives, particularly those implemented within individual practices, were considered most acceptable. Initiatives that demanded cooperation from entities outside practices, or those regarded as punitive, were less acceptable.

LIMITATIONS

The findings of this voluntary survey may be biased towards particularly motivated respondents in the veterinary sector. Additionally, the cause or effect of the recorded professional behaviour is not known in this study.

CONCLUSION

Future antimicrobial policy should consider AMS acceptability by veterinarians, alongside farmers and other stakeholders, to promote compliance and attainment. The study data suggest that veterinarians may perceive continuous professional development/knowledge exchange as being most acceptable, alongside activities allied to a strong veterinarian‒client prescribing relationship. Continued support should focus on expanding these areas. Decoupling (ie, abolishing the professional licence for veterinarians to both prescribe and dispense medicines) was viewed as least acceptable by veterinarians in this study.

Development of a Method for the Determination of Rifaximin and Rifampicin Residues in Foods of Animal Origin

Rifaximin and rifampicin are good broad-spectrum antimicrobials. The irrational use of antimicrobial drugs in veterinary clinics could threaten public health and food safety. It is necessary to develop a reliable detection method of the residue for enhancing the rational supervision of the use of such drugs, reducing and slowing down the generation of bacterial resistance, and promoting animal food safety and human health. So, this study developed an LC-MS/MS method for the detection of rifaximin and rifampicin residues in animal-origin foods. The residual rifaximin and rifampicin of homogenized test materials were extracted with acetonitrile-dichloromethane solution or acetonitrile in the presence of anhydrous sodium sulfate and vitamin C, purified by dispersible solid phase extraction, determined by LC-MS/MS, and quantified by the internal standard method. The specificity, sensitivity, matrix effect, accuracy, and precision of the method were investigated in the edible tissues of cattle, swine, or chicken. In addition, the stability of the standard stock solution and the standard working solution was also investigated. The method was suitable for the muscle, liver, kidney, fat, milk, and eggs of cattle, swine, or chicken, as well as fish and shrimp. The specificity of the method was good, and the detection of the analytes was not affected by different matrices. Both the LOD and LOQ of the two analytes were 5 μg/kg and 10 μg/kg, respectively. The results of matrix effects in each tissue were in the range of 80-120%; there were no significant matrix effects. The average accuracy of rifaximin and rifampicin in different foodstuffs of animal origin was between 80% and 120%, and the method precision was below 20% (RSD). The proposed method showed good performance for determination, which could be employed for the extraction, purification, and detection of residual rifaximin and rifampicin in edible animal tissues. The pretreatment procedure of tissue samples was simple and feasible. The method was highly specific, stable, reliable, and with high sensitivity, accuracy, and precision, which met the requirements of quantitative detection of veterinary drug residues.

Progress and Challenges: Implementation of the UK Antimicrobial Resistance National Action Plan 2019-2024 within the Beef Cattle Sub-Sector

The five-year UK antimicrobial resistance (AMR) National Action Plan (NAP) was published in 2019 focusing on reducing the need for, and unintentional exposure to antimicrobials (AMs); optimising the use of AMs; and investing in innovation, supply and access of AMs. This study aimed to evaluate the progress made in the beef cattle sub-sector in addressing specific NAP commitments related to improving animal health and welfare and responsible antimicrobial use (AMU). A thematic analysis was conducted of 21 semi-structured interviews with stakeholders from government organisations, farms, veterinary practices, levy boards and livestock associations. The findings indicate substantial progress, with various initiatives implemented targeting data collection, farmer and veterinarian engagement, and herd health planning. However, there remain a number of challenges and barriers that need to be addressed in order to assess the impacts of these initiatives, such as the availability of AMU and AMR data. Ensuring the adequacy of resources was found to be critical for the sustainability of effective initiatives, considering competing demands on people's time. Additionally, the importance of other outcomes from these initiatives such as developing and strengthening the farmer-veterinarian relationship should not be underestimated since it is fundamental to successfully addressing issues such as AMR.

Residue depletion of enrofloxacin and flumequine in feathers of broilers based on quantitative UHPLC-MS/MS detection

To explore potential factors contributing to high fluoroquinolone resistance levels, it is essential to develop analytical methods capable of detecting residues and trace amounts of antibiotic use in broilers. The aim of the present study was to develop and in-house validate a sensitive UHPLC-MS/MS method capable of determining enrofloxacin (ENR) and flumequine (FLU) residues at slaughter age (day 45) when the animals were treated with these antimicrobials one day after hatching. Residue depletion of ENR and FLU in feathers was also assessed. Two experimental trials were performed, both consisting of 5 different treatment groups. In the first trial animals were treated with ENR and in the second one with FLU. The developed method was successfully validated and was found to be sensitive enough to detect residues of fluoroquinolones in the feathers up until slaughter age in all treatment groups. Average ENR concentration on day 45 was 10 ng g-1 feather after drinking water treatment, with all concentrations above the limit of quantification (LOQ) of 5 ng g-1 feather. For FLU average concentration on day 45 after drinking water administration was 4 ng g-1 feather, with an LOQ of 1 ng g-1 feather. Therefore, the method is suited for application to monitor fluoroquinolone use in broilers.

Dietary Exposure to Pesticide and Veterinary Drug Residues and Their Effects on Human Fertility and Embryo Development: A Global Overview

Drug residues that contaminate food and water represent a serious concern for human health. The major concerns regard the possible irrational use of these contaminants, since this might increase the amplitude of exposure. Multiple sources contribute to the overall exposure to contaminants, including agriculture, domestic use, personal, public and veterinary healthcare, increasing the possible origin of contamination. In this review, we focus on crop pesticides and veterinary drug residues because of their extensive use in modern agriculture and farming, which ensures food production and security for the ever-growing population around the world. We discuss crop pesticides and veterinary drug residues with respect to their worldwide distribution and impacts, with special attention on their harmful effects on human reproduction and embryo development, as well as their link to epigenetic alterations, leading to intergenerational and transgenerational diseases. Among the contaminants, the most commonly implicated in causing such disorders are organophosphates, glyphosate and antibiotics, with tetracyclines being the most frequently reported. This review highlights the importance of finding new management strategies for pesticides and veterinary drugs. Moreover, due to the still limited knowledge on inter- and transgenerational effects of these contaminants, we underlie the need to strengthen research in this field, so as to better clarify the specific effects of each contaminant and their long-term impact.

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

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

Climate change and resilience for antimicrobial stewardship and infection prevention

PURPOSE OF REVIEW

This review covers recent research regarding the challenges posed by climate change within the areas of antimicrobial stewardship and infection prevention, and ways to build resiliency in these fields.

RECENT FINDINGS

Infectious disease patterns are changing as microbes adapt to climate change and changing environmental factors. Capacity for testing and treating infectious diseases is challenged by newly emerging diseases, which exacerbate challenges to antimicrobial stewardship and infection prevention.Antimicrobial resistance is accelerated due to environmental factors including air pollution, plastic pollution, and chemicals used in food systems, which are all impacted by climate change.Climate change places infection prevention practices at risk in many ways including from major weather events, increased risk of epidemics, and societal disruptions causing conditions that can overwhelm health systems. Researchers are building resilience by advancing rapid diagnostics and disease modeling, and identifying highly reliable versus low efficiency interventions.

SUMMARY

Climate change and associated major weather and socioeconomic events will place significant strain on healthcare facilities. Work being done to advance rapid diagnostics, build supply chain resilience, improve predictive disease modeling and surveillance, and identify high reliability versus low yield interventions will help build resiliency in antimicrobial stewardship and infection prevention for escalating challenges due to climate change.

Streambed immobilization controls the transport of antibiotic resistance genes in flowing water

Antibiotic resistance is a serious global health issue, resulting in at least 1.2 million deaths in 2019. The environment is a potentially important reservoir of antibiotic resistance; however, the fate of Antibiotic Resistance Genes (ARGs) in the environment remains poorly characterized. One important environmental source of ARGs is manure used as a soil amendment. ARGs from manure may then enter nearby flowing waterbodies, where the factors governing their downstream transport remain unknown. To address this, we conducted experiments by spiking cattle manure in an artificial stream to estimate removal rates (k; m-1) for three ARGs (mefA, tetQ, and tetW) and a ruminant fecal marker (bacR). We then used a Stochastic Mobile-Immobile Model (SMIM) to separate the overall removal into two components, rs, and rh, corresponding to immobilizations in the surface (i.e., water column) and subsurface (i.e., streambed), respectively. Finally, we applied the SMIM across four model streams to predict the downstream travel distance of ARGs and bacR. Our results showed measurable removal for all targets in all experimental replicates (n = 3) and no differences were found in the removal rates among replicates for any target (ANCOVA; p > 0.05). We found that the removal of bacR was significantly lower than tetW (p < 0.05) and slightly lower than mefA (p = 0.088), while tetQ removal was slightly different from tetW's (p = 0.072). We also found that rh values were orders of magnitude larger than rs for ARGs and bacR (t-test; p < 0.05). These findings suggest that ARGs and bacR are being removed from the water column through immobilization reactions occurring in the streambed. Additionally, we predicted that the 90 % removal (or D90) of targets occurs within the first 500 m in all model streams except in a slow-flow pastoral stream, which required 1400 m of downstream transport for 90 % removal. Our findings and model stand out as promising tools to predict the fate of ARGs in streams and will contribute to improving and managing agricultural practices that employ animal manure.

Comparative Antimicrobial Resistance and Prevalence of Methicillin Resistance in Coagulase-Positive Staphylococci from Conventional and Organic Dairy Farms in South Korea

Bovine mastitis (BM) has caused huge economic and financial losses in the dairy industry worldwide, with Staphylococcus aureus as one of its major pathogens. BM treatment still relies on antibiotics and its extensive use often generates methicillin-resistant S. aureus (MRSA) and mupirocin-resistant S. aureus (MuRSA). This study compared the antimicrobial resistance trend in coagulase-positive Stapholococci (CoPS) isolated from BM milk in conventional and organic dairy farms and checked prevalence of MRSA and MuRSA. A total of 163 presumptive Staphylococci were isolated, wherein 11 out of 74 from 4 conventional farms (CF1, CF2, CF3, CF4) and 17 out of 89 from 3 organic farms (OF1, OF2, OF3) exhibited coagulase activity. Multiplex-PCR amplification confirmed at least one coagulase-positive isolate from CF1, CF2, CF3, CF4, and OF1 as S. aureus, denoted by the presence of the nuc gene. Three isolates from CF2 contained the mecA gene, indicating MRSA prevalence, while the MuRSA gene marker, mupA, was not detected in any of the isolates. Antimicrobial testing showed that conventional farm isolates were more resistant to antibiotics, especially ampicillin and tetracycline. This suggests a risk of developing multidrug resistance in dairy farms if antibiotic use is not properly and strictly monitored and regulated.

High frequency of multidrug-resistant Escherichia coli from cattle in the Cerrado and Pantanal biomes of Brazil

The indiscriminate use of antimicrobials has led to the emergence of resistant bacteria, especially pathogenic strains of Escherichia coli, which are associated with diseases in animals and humans. The aim of the present study was to characterize E. coli isolates in calves with regards to the presence of virulence genes and investigate the resistance of the isolates to different antimicrobials. Between 2021 and 2023, 456 fecal samples were collected from calves in the Pantanal and Cerrado biomes of the state of Mato Grosso do Sul, Brazil. All samples were subjected to microbiological analysis and disc diffusion antibiogram testing. The polymerase chain reaction method was used to detect virulence genes. Bacterial growth was found in 451 of the 456 samples and biochemically identified as Escherichia coli. All 451 isolates (100 %) exhibited some phenotypic resistance to antimicrobials and 67.62 % exhibited multidrug resistance. The frequency of multidrug-resistant isolates in the Cerrado biome was significantly higher than that in the Pantanal biome (p = 0.0001). In the Cerrado, the most common pathotype was Shiga toxin-producing Escherichia coli (STEC) (28 %), followed by toxigenic Escherichia coli (ETEC) (11 %), enterohemorrhagic Escherichia coli (EHEC) (8 %) and enteropathogenic Escherichia coli (EPEC) (2 %). In most cases, the concomitant occurrence of pathotypes was more common, the most frequent of which were ETEC + STEC (33 %), ETEC + EHEC (15 %) and ETEC + EPEC (3 %). The STEC pathotype (30 %) was also found more frequently in the Pantanal, followed by EHEC (12 %), ETEC (9 %) and EPEC (6 %). The STEC pathotype had a significantly higher frequency of multidrug resistance (p = 0.0486) compared to the other pathotypes identified. The frequency of resistance was lower in strains from the Pantanal biome compared to those from the Cerrado biome. Although some factors are discussed in this paper, it is necessary to clarify the reasons for this difference and the possible impacts of these findings on both animal and human health in the region.

Factors Associated with Inappropriate Use of Antibiotics Among Animal Health Professionals in Selected Districts of Rwanda, 2021

BACKGROUND

Antibiotic resistance is a global health concern. Humans can acquire antibiotic resistance through human-to-human transmission, from the environment, via the food chain, and through the contact with animals. The National Action Plan on antimicrobial resistance 2020-2024 highlights the prudent use of antibiotics in veterinary activities as the key element in keeping antibiotics effective. We determined the factors associated with misuse of antibiotics among animal health professionals in Rwanda.

METHODS

This was a cross-sectional study that enrolled animal health field professionals from five districts, where stratified random sampling was used to select one district by each province of Rwanda. Structured questions were used during face-to-face interviews. The misuse of antibiotics was defined as the use of antibiotics for reasons other than treatment, the non-completion of required courses, or the use of a high dose (i.e., an overdose) of antibiotics. We collected socio-demographic data of respondents, as well as elementary knowledge and perceptions on veterinary antibiotics and antibiotic resistance. A backward stepwise logistic regression model was used to identify the factors that were predictive of the inappropriate use of antibiotics.

RESULTS

There were 256 respondents to the survey. Of those, 198 were male and 58 were female. Almost three quarters of respondents (n = 174/256; 68%) reported the misuse of antibiotics at least once in the previous 12 months. The final logistic regression analysis identified the following factors to be predictive of antibiotics misuse: aged ≤ 24 years (aOR 0.92; 95% CI [0.88, 0.96]; p < 0.001); low trust in veterinary antibiotics available in the local market (aOR 8.45; 95% CI [4.18, 17.07]; p < 0.01), insufficient knowledge about basic understanding of antibiotics and antibiotic resistance (aOR 2.78; 95% CI [1.38, 5.58], p < 0.01) and not acquiring any continuing education (aOR 1.97; 95% CI [1.02, 4.19]; p = 0.04).

CONCLUSIONS

This study identified inadequate perceptions of proper antibiotic use among animal health professionals. There is a need for continuous education on appropriate antibiotic use among animal health professionals to lessen the negative impact of antibiotic resistance on public health security.

Effect of prudent use of antimicrobials in the early phase of infection in pigs on the performance and meat quality of fattening pigs

The presented study was a part of the ThermoEye project. The study examined the effect of prudent antibiotic treatment in response to illness on the fattening performance, slaughter traits, and meat quality of the pig fatteners. Pigs were divided into an experimental group - EXP and a control - CON. In both groups, the body temperature was monitored, and diseases were confirmed by a veterinarian. In the EXP group, metaphylaxis was used in each case of confirmed disease. The EXP fatteners had greater slaughter weight (by 4.7 kg) and meatiness (by 2.1 percentage points) compared to the CON pigs. The pH in pork was lower in EXP compared to CON pigs. The longissimus thoracis et lumborum of EXP pigs was characterised by a lower cooking loss (28.30 vs. 30.45%) and yellower colour compared to the CON group. Among the amino acids, only the content of histidine (by 5.2%; P < 0.01) and tyrosine (by 7.2%; P < 0.01) was significantly greater in the meat of the CON group compared to EXP, with no effect of sex noted. The content of SFA (by 14.6%; P < 0.05), UFA (by 15.6%; P < 0.05), MUFA (by 17.8%; P < 0.05), MCFA (by 14.1%; P < 0.05), and LCFA (by 15.6%; P < 0.05) was also greater in CON compared to EXP meat. In conclusion, automated monitoring of pig body temperature during the fattening period enables more precise, prudent treatment and effective animal health control while reducing costs due to disease losses and pharmacotherapy. It allows optimal production and affects meat quality.

Unveiling the genomic landscape of Salmonella enterica serotypes Typhimurium, Newport, and Infantis in Latin American surface waters: a comparative analysis

Surface waters are considered ecological habitats where Salmonella enterica can persist and disseminate to fresh produce production systems. This study aimed to explore the genomic profiles of S. enterica serotypes Typhimurium, Newport, and Infantis from surface waters in Chile, Mexico, and Brazil collected between 2019 and 2022. We analyzed the whole genomes of 106 S. Typhimurium, 161 S. Newport, and 113 S. Infantis isolates. Our phylogenetic analysis exhibited distinct groupings of isolates by their respective countries except for a notable case involving a Chilean S. Newport isolate closely related to two Mexican isolates, showing 4 and 13 single nucleotide polymorphisms of difference, respectively. The patterns of the most frequently detected antimicrobial resistance genes varied across countries and serotypes. A strong correlation existed between integron carriage and genotypic multidrug resistance (MDR) across serotypes in Chile and Mexico (R > 0.90, P < 0.01), while integron(s) were not detected in any of the Brazilian isolates. By contrast, we did not identify any strong correlation between plasmid carriage and genotypic MDR across diverse countries and serotypes.IMPORTANCEUnveiling the genomic landscape of S. enterica in Latin American surface waters is pivotal for ensuring public health. This investigation sheds light on the intricate genomic diversity of S. enterica in surface waters across Chile, Mexico, and Brazil. Our research also addresses critical knowledge gaps, pioneering a comprehensive understanding of surface waters as a reservoir for multidrug-resistant S. enterica. By integrating our understanding of integron carriage as biomarkers into broader MDR control strategies, we can also work toward targeted interventions that mitigate the emergence and dissemination of MDR in S. enterica in surface waters. Given its potential implications for food safety, this study emphasizes the critical need for informed policies and collaborative initiatives to address the risks associated with S. enterica in surface waters.

Evaluation of cattle farmers' knowledge, attitudes, and practices regarding antimicrobial use and antimicrobial resistance in Rwanda

The misuse of antimicrobials in livestock may lead to the emergence and spread of resistant pathogens harmful to human, animal, and environmental health. Therefore, determining the behavior and practices of farmers regarding antimicrobial use (AMU) and antimicrobial resistance (AMR) is crucial for addressing the growing threat of AMR. This cross-sectional study was conducted in the Eastern Province of Rwanda on 441 participants using a structured questionnaire to determine the knowledge, attitudes, and practices (KAP) towards AMU and AMR. Frequency distributions, chi-square test of association and logistic regression model were used to analyze the data. This study showed poor biosecurity measures at the farm level with various antimicrobials used here; 83.9% of participants obtained them from friends and neighbors and 61.9% used them for growth promotion. Our assessment revealed a low level of KAP towards AMR among cattle farmers from the study districts. Our data showed that at a 69% cutoff, only 52.6% of farmers had correct knowledge, whereas 56% had good attitudes (47% cutoff). Finally, 52.8% had correct practices toward AMR based on a calculated cutoff of 50%. Positive attitudes, correct knowledge, and practices regarding AMU and AMR were associated with higher educational levels. Sex was correlated with knowledge and attitudes, whereas farm location was associated with attitudes and practices. Farmers expressed a need for more access to veterinary services and AMR-related training for themselves, the community animal health workers, and veterinarians. This study highlighted the low levels of KAP associated with using antimicrobials, which may lead to the misuse of antimicrobials and the spread of AMR. It is imperative to develop and implement cross-cutting measures to minimize antibiotic usage and reduce the risk of antibiotic resistance.

Antimicrobial resistance of Escherichia coli from dairy farms participating in an antimicrobial stewardship educational program for farm employees

Antimicrobial use in food-producing animals is under increasing scrutiny due to the potential effect on the selection of antimicrobial-resistant bacteria that may be transmitted to humans by direct contact, with the food chain, or the environment. Novel data monitoring commensal Escherichia coli from dairy farms is essential for understanding antimicrobial resistance (AMR) patterns and their association with herd health management practices. The objectives of this study were to: (1) compare the prevalence of antimicrobial resistance in the E. coli isolates from the hospital, fresh, and mid-lactation pens from 18 conventional dairy farms participating in an educational training program in antimicrobial stewardship practices in California and Ohio, and (2) to characterize the prevalence of antimicrobial resistance of commensal E. coli isolated from pooled fecal pat samples before and 3 mo after participating in the educational training program. Pooled fecal pat samples were collected from the hospital pen, the fresh pen (1 to 5 DIM), and the mid-lactation pens (90 to 150 DIM) on conventional dairies in CA (n = 9) and OH (n = 9). Fecal samples were collected as part of a larger study using a quasi-experimental design that assigned farms to the training intervention group (TG; 6 per state) or the control group (CG; 3 per state). For the TG, farm worker(s) identified as having the task of diagnosis and treatment of adult cows on the farm participated in a training program on antimicrobial stewardship practices. Pooled fecal samples (n = 7) were collected at enrollment and 3 mo after completing the intervention on each of the participating farms (n = 18), followed by culture for E. coli isolation and antimicrobial sensitivity testing using the broth microdilution methodology. Logistic regression models were used to evaluate the association between E. coli antimicrobial resistance patterns with the training intervention and farm-level factors. No effect was observed in the prevalence of resistant isolates between the control and intervention farms after the training was delivered. Isolates from the hospital pens were 2.48 (95% CI: 1.06-6.22, P = 0.03) and 5.61 (95% CI: 1.94-16.91, P < 0.001) times, more likely to be resistant to streptomycin and chloramphenicol, respectively, than isolates from the mid-lactation pens. Our findings indicate there was a higher prevalence of AMR in E. coli associated with the hospital pen within the farm, while the training program for 3 mo did not affect the prevalence of AMR in E. coli on the farms participating in the program. Further research efforts should be conducted to identify factors driving AMR at the pen level, as well as approaches that could be used to reduce the risk of disseminating AMR from sick pens to animals being housed and to other pens on the farm.

Antimicrobial resistance profiles of Escherichia coli derived from an integrated agroforestry-livestock system in Deli Serdang Regency, Indonesia

Background and Aim

Antimicrobial resistance (AMR) has become a significant global concern. Epidemiological data do not provide a robust description of the potential risks associated with AMR in the integrated agroforestry-livestock systems in Indonesia. Thus, the present study investigated the phenotypic and multidrug resistance (MDR) profiles of Escherichia coli strains isolated from the feces of livestock raised in the agro-silvopastoral system in Deli Serdang Regency, North Sumatra Province.

Materials and Methods

A standard microbiological culture procedure was followed to isolate the organism and test antibiotic susceptibility using the Kirby-Bauer disk diffusion protocol. Furthermore, the multiple antibiotic resistance index was determined. Univariate analysis was conducted to identify the risk factors associated with AMR.

Results

The vast majority (77.5%) of livestock farmers were aged >30 years. All farmers were men and had no higher education (100% of them). The majority of the animal species managed were cattle and goats (37.5% each) and the livestock grazing pasture system (67.5%). In addition, the majority of farmers reported high antimicrobial use on their farms (87.5%). Of the samples (n = 142) analyzed, n = 70 were positive, with an overall prevalence of 44.4%. The species-specific prevalences of E. coli were 32.5%, 47.8%, and 50% in buffalo, goat, and cattle, respectively. Ampicillin and tetracyclines exhibited high resistance levels among the studied animal species. A relatively lower MDR for E. coli was associated with grazing on the pasture.

Conclusion

The findings from the current study provide baseline epidemiological information for future robust studies aimed at elucidating the drivers and patterns of AMR in agro-silvopastoral systems in the study area or elsewhere.

Assessment of the Implementation of Pakistan's National Action Plan on Antimicrobial Resistance in the Agriculture and Food Sectors

The agriculture and food (agrifood) sectors play key roles in the emergence, spread, and containment of antimicrobial resistance (AMR). Pakistan's first National Action Plan (NAP) on AMR was developed to guide One Health interventions to combat AMR through 2017-2022. To improve subsequent iterations, we assessed the implementation of Pakistan's NAP in the agrifood sectors (NAPag) in October 2022, using the Progressive Management Pathway on AMR tool developed by the Food and Agriculture Organization of the United Nations (FAO). The assessment tool addressed four crucial focus areas of the NAPag: governance, awareness, evidence, and practices. Each focus area contains multiple topics, which involve four sequential stages of activities to progressively achieve systematic management of AMR risk in the agrifood sectors. High-level representatives of the NAPag stakeholders provided information for the assessment through pre-event documentary review and workshop discussions. The assessment results showed that Pakistan's NAPag had an overall moderate coverage (59%) of the anticipated activities. Gaps were particularly notable in strengthening governance, good practices, and interventions in non-livestock sectors. Furthermore, only 12% of the evaluated activities were fully executed and documented, consistently remaining at the planning and piloting stages in the livestock sector across all the examined topics. Insufficient attention to non-livestock sectors, inadequate regulation and enforcement capacity, and resource constraints have hindered scalable and sustainable interventions under the current plan. This assessment provides valuable insights to strengthen the inclusiveness and contribution of the agrifood sectors in the next NAP iteration. In the short-to-medium term, strategic prioritization is necessary to optimize the use of limited resources and target the most critical gaps, such as improving awareness among key stakeholders and fortifying regulations for prudent antimicrobial use. In the long term, integration of AMR into the country's broader health, development, and agricultural transformation agendas will be needed to generate sustainable benefits.

Temporal variations of antimicrobial resistance genes in aerosols: A one-year monitoring at the puy de Dôme summit (Central France)

The recent characterization of antibiotic resistance genes (ARGs) in clouds evidenced that the atmosphere actively partakes in the global spreading of antibiotic resistance worldwide. Indeed, the outdoor atmosphere continuously receives large quantities of particles of biological origins, emitted from both anthropogenic or natural sources at the near Earth's surface. Nonetheless, our understanding of the composition of the atmospheric resistome, especially at mid-altitude (i.e. above 1000 m a.s.l.), remains largely limited. The atmosphere is vast and highly dynamic, so that the diversity and abundance of ARGs are expected to fluctuate both spatially and temporally. In this work, the abundance and diversity of ARGs were assessed in atmospheric aerosol samples collected weekly between July 2016 and August 2017 at the mountain site of puy de Dôme (1465 m a.s.l., central France). Our results evidence the presence of 33 different subtypes of ARGs in atmospheric aerosols, out of 34 assessed, whose total concentration fluctuated seasonally from 59 to 1.1 × 105 copies m-3 of air. These were heavily dominated by genes from the quinolone resistance family, notably the qepA gene encoding efflux pump mechanisms, which represented >95 % of total ARGs concentration. Its abundance positively correlated with that of bacteria affiliated with the genera Kineococcus, Neorhizobium, Devosia or Massilia, ubiquitous in soils. This, along with the high abundance of Sphingomonas species, points toward a large contribution of natural sources to the airborne ARGs. Nonetheless, the increased contribution of macrolide resistance (notably the erm35 gene) during winter suggests a sporadic diffusion of ARGs from human activities. Our observations depict the atmosphere as an important vector of ARGs from terrestrial sources. Therefore, monitoring ARGs in airborne microorganisms appears necessary to fully understand the dynamics of antimicrobial resistances in the environment and mitigate the threats they may represent.

Global antimicrobial resistance and use surveillance system (GLASS 2022): Investigating the relationship between antimicrobial resistance and antimicrobial consumption data across the participating countries

For the first time since 2015, the World Health Organization's (WHO) global Antimicrobial Resistance and Use Surveillance (GLASS) featured both global reports for antimicrobial resistance (AMR) and antimicrobial consumption (AMC) data in its annual reports. In this study we investigated the relationship of AMR with AMC within participating countries reported in the GLASS 2022 report. Our analysis found a statistically significant correlation between beta-lactam/cephalosporin and fluoroquinolones consumption and AMR to these antimicrobials associated with bloodstream E. coli and Klebsiella pneumoniae among the participating countries (P<0.05). We observed that for every 1 unit increase in defined daily dose DDD of beta-lactam/cephalosporins and quinolone consumptions among the countries, increased the recoveries of bloodstream-associated beta-lactam/cephalosporins-resistant E. coli/Klebsiella spp. by 11-22% and quinolone-resistant E. coli/Klebsiella spp. by 31-40%. When we compared the antimicrobial consumptions between the antimicrobial ATC (Alphanumeric codes developed by WHO) groups and countries, we observed a statistically significant higher daily consumption of beta-lactam-penicillins (J01C, DDD difference range: 5.23-8.13) and cephalosporins (J01D, DDD difference range: 2.57-5.13) compared to other antimicrobial groups among the countries (adjusted for multiple comparisons using Tukey's method). Between the participating countries, we observed a statistically significant higher daily consumption of antimicrobial groups in Iran (DDD difference range: 3.63-4.84) and Uganda (DDD difference range: 3.79-5.01) compared to other participating countries (adjusted for multiple comparisons using Tukey's method). Understanding AMC and how it relates to AMR at the global scale is critical in the global AMR policy development and implementation of global antimicrobial stewardship.

European Food Safety Authority (EFSA), European Centre for Disease Prevention and Control (ECDC). The European Union summary report on antimicrobial resistance in zoonotic and indicator bacteria from humans, animals and food in 2021-2022

This report by the European Food Safety Authority and the European Centre for Disease prevention and Control, provides an overview of the main findings of the 2021-2022 harmonised Antimicrobial Resistance (AMR) monitoring in Salmonella spp., Campylobacter jejuni and C. coli from humans and food-producing animals (broilers, laying hens and fattening turkeys, fattening pigs and cattle under one year of age) and relevant meat thereof. For animals and meat thereof, AMR data on indicator commensal Escherichia coli, presumptive extended-spectrum beta-lactamases (ESBL)-/AmpC beta-lactamases (AmpC)-/carbapenemase (CP)-producing E. coli, and the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) are also analysed. Generally, resistance levels differed greatly between reporting countries and antimicrobials. Resistance to commonly used antimicrobials was frequently found in Salmonella and Campylobacter isolates from humans and animals. In humans, increasing trends in resistance to one of two critically antimicrobials (CIA) for treatment was observed in poultry-associated Salmonella serovars and Campylobacter, in at least half of the reporting countries. Combined resistance to CIA was however observed at low levels except in some Salmonella serovars and in C. coli from humans and animals in some countries. While CP-producing Salmonella isolates were not detected in animals in 2021-2022, nor in 2021 for human cases, in 2022 five human cases of CP-producing Salmonella were reported (four harbouring bla OXA-48 or bla OXA-48-like genes). The reporting of a number of CP-producing E. coli isolates (harbouring bla OXA-48, bla OXA-181, bla NDM-5 and bla VIM-1 genes) in fattening pigs, cattle under 1 year of age, poultry and meat thereof by a limited number of MSs (5) in 2021 and 2022, requires a thorough follow-up. The temporal trend analyses in both key outcome indicators (rate of complete susceptibility and prevalence of ESBL-/AmpC-producers in E. coli) showed an encouraging progress in reducing AMR in food-producing animals in several EU MSs over the last 7 years.

Antimicrobial resistance in Escherichia coli isolated from pigs and associations with aggregated antimicrobial usage in Ireland: A herd-level exploration

AIMS

Antimicrobial resistance (AMR) is of significant global concern and is a major One Health issue. There is evidence to suggest that increased antimicrobial usage (AMU) can be associated with AMR patterns, and therefore, there have been efforts to reduce AMU in anticipation of reducing AMR emergence risk. The aim of this study was to investigate whether there were any associations between AMU and AMR patterns of commensal Escherichia coli isolated from pig herds in Ireland.

METHODS AND RESULTS

Data on AMR from a panel of antimicrobials (AMDs) were gathered as part of national surveillance activities. These data were associated with reported usage of AMDs, on a year-quarter basis, measured in mg/kg at a herd-level using generalized estimating equation regression analysis. Associations were tested with AMR presence or multi-drug resistance (MDR; ≥3 classes) profiles and total AMU during the contemporaneous quarter and previous quarter, respectively. Furthermore, individual and AMD class-based associations were tested. The final dataset contained 218 observations (herd-quarter usage and AMR resistance profile) from 122 herds during 2019-2021. Apparent resistance prevalence varied according to AMD type, with the highest mean prevalence found with tetracycline at 51.57% (95% CI: 45.06%-58.09%). There were significant associations between a herd obtaining a positive AMR result for any AMDs and the overall levels of AMU during the year-quarter. Furthermore, there were significant positive associations between MDR and total AMU. At the compound level, chloramphenicol resistance was significantly associated with increased usage of trimethoprim/sulfadiazine and chlortetracycline, respectively (p < 0.010). Tetracycline resistance was associated with increased use of chlortetracycline (p = 0.008). At the antimicrobial class level, there was a significant positive relationship between the usage of phenicol and the probability of a resistance for chloramphenicol (p = 0.026) and between the usage of tetracycline and tetracycline resistance probability (p = 0.018).

CONCLUSIONS

Our data provide evidence of associations between overall AMU and AMR or MDR risk at the herd-quarter level. There was also evidence of associations between specific AMDs and patterns of resistance. Associations varied depending on whether time lags in usage were modelled or how usage was modelled (e.g. dichotomized or continuous). Associations with rarely used AMDs (e.g. critically important AMDs) were precluded due to a lack of statistical power. Continued monitoring of both AMU and AMR is crucial to assess the impacts of policy changes aimed at reducing AMU.

European Centre for Disease Prevention and Control (ECDC), European Food Safety Authority (EFSA), European Medicines Agency (EMA). Antimicrobial consumption and resistance in bacteria from humans and food-producing animals: Fourth joint inter-agency report on integrated analysis of antimicrobial agent consumption and occurrence of antimicrobial resistance in bacteria from humans and food-producing animals in the EU/EEA JIACRA IV - 2019-2021

The fourth joint inter-agency report on integrated analysis of antimicrobial consumption (AMC) and the occurrence of antimicrobial resistance (AMR) in bacteria from humans and food-producing animals (JIACRA) addressed data obtained by the Agencies' EU-wide surveillance networks for 2019-2021. The analysis also sought to identify whether significant trends in AMR and AMC were concomitant over 2014-2021. AMC in both human and animal sectors, expressed in mg/kg of estimated biomass, was compared at country and European level. In 2021, the total AMC was assessed at 125.0 mg/kg of biomass for humans (28 EU/EEA countries, range 44.3-160.1) and 92.6 mg/kg of biomass for food-producing animals (29 EU/EEA countries, range 2.5-296.5). Between 2014 and 2021, total AMC in food-producing animals decreased by 44%, while in humans, it remained relatively stable. Univariate and multivariate analyses were performed to study associations between AMC and AMR for selected combinations of bacteria and antimicrobials. Positive associations between consumption of certain antimicrobials and resistance to those substances in bacteria from both humans and food-producing animals were observed. For certain combinations of bacteria and antimicrobials, AMR in bacteria from humans was associated with AMR in bacteria from food-producing animals which, in turn, was related to AMC in animals. The relative strength of these associations differed markedly between antimicrobial class, microorganism and sector. For certain antimicrobials, statistically significant decreasing trends in AMC and AMR were concomitant for food-producing animals and humans in several countries over 2014-2021. Similarly, a proportion of countries that significantly reduced total AMC also registered increasing susceptibility to antimicrobials in indicator E. coli from food-producing animals and E. coli originating from human invasive infections (i.e., exhibited 'complete susceptibility' or 'zero resistance' to a harmonised set of antimicrobials). Overall, the findings suggest that measures implemented to reduce AMC in food-producing animals and in humans have been effective in many countries. Nevertheless, these measures need to be reinforced so that reductions in AMC are retained and further continued, where necessary. This also highlights the importance of measures that promote human and animal health, such as vaccination and better hygiene, thereby reducing the need for use of antimicrobials.