Antimicrobials In Food-producing Animals Research Articles

Veterinarians approach towards antimicrobial stewardship and one health: A survey study.

Antimicrobial resistance (AMR) is one of the top 10 global public health threats. One Health approach is needed to tackle antimicrobial resistance as most antimicrobials used in animals are also used in humans and affect the environment. Although the knowledge and attitudes of personnel in the human healthcare sector are studied more frequently in Gujarat, veterinarians' approaches also play a pivotal role in attaining antimicrobial stewardship. Thus, an online survey was conducted to understand the knowledge, attitudes, and practices of veterinarians regarding AMR and antimicrobial stewardship in Gujarat. A total of 691 respondents included 300 government veterinarians (44%), 258 cooperative veterinarians (37%), 45 private veterinarians (5%), 69 MVD GVK veterinarians (10%), and 19 others (4%). Several veterinarians (77%) believe that farmers' misuse of antimicrobials contributes significantly to AMR. According to 78% of respondents, the inappropriate use of antimicrobials in food-producing animals contributes to AMR, which can be reduced by vaccines, biosecurity measures, and hygiene (79%). As per 86% of the responders, antimicrobial stewardship is important, and 81% educate farmers on the rational use of antimicrobials. Though 92% of veterinarians agreed that culture and antimicrobial sensitivity testing (AST) should be done as frequently as possible to guide antimicrobial usage, only 4% always, and 68% sometimes send samples for AST. However, 31% think it is acceptable to commence antimicrobial therapy without a confirmatory diagnosis. The study findings suggest that AMR awareness among farmers, increased provision of laboratory services, and AST at affordable costs should be developed to combat the development of AMR.

Phytogenic feed additives as alternatives to antibiotics in poultry production: A review

The overuse of antimicrobials in food-producing animals, particularly poultry, has led to growing concerns about multidrug microbial resistance, posing significant risks to both human and animal health. Subtherapeutic doses of antibiotics have traditionally been used to enhance growth and improve economic efficiency in poultry farming. However, these practices have facilitated the emergence of resistant microbial strains, threatening global health security and prompting a search for sustainable alternatives. This review highlights the significance of phytogenic as feed additives (PFAs) as promising substitutes for antibiotic as feed additives (AFAs) in poultry production. PFAs, derived from plant-based compounds, exhibit multiple beneficial properties, including antimicrobial, antioxidative, anti-inflammatory, and immune-modulatory effects. Moreover, they offer the potential to produce high-quality organic poultry products while reducing the likelihood of microbial resistance. Despite these advantages, inconsistent results among studies underscore the importance of standardized approaches to maximize their efficacy. This review aims to evaluate the current status of antibiotic use in poultry farming globally, explore the properties and mechanisms of PFAs, and assess their potential as viable alternatives to antibiotics. By consolidating available knowledge, this review provides insights into the benefits and challenges associated with PFAs, offering guidance for future research and practical applications in sustainable poultry production. Keywords: alternatives, antibiotics, phytogenic, poultry production.

Consumption of antimicrobials for use in food-producing animals in New Zealand, a measure of progress in reduction from 2015 to 2022

ABSTRACT Aims To describe progress in the reduction of the consumption of antimicrobial drugs by food-producing animals in New Zealand to 2022 and to identify the animal production sectors where progress has been greatest, and those where opportunities remain. Methods Data were sourced from official government and industry reports to update previous estimates of consumption (as sales) of antimicrobial products applied to food-producing animals in New Zealand, European countries and the USA. Antimicrobial consumption (AMC) was estimated based on the amount of active ingredient sold, per kg of animal biomass standardised to the probable weight at time of treatment or lifetime mean weight but not slaughter weight (population correction unit; PCU). This methodology is widely used for international comparisons. Results The estimated gross consumption of antimicrobials in food-producing animals in New Zealand increased steadily from 2005 to 2013 (from 7.54 to 11.28 mg/PCU). From 2014 to 2018 the estimate flattened to a 5-year rolling mean of 10.40 mg/PCU. In 2019–2021 the consumption dropped. The NZ consumption in 2022 was substantially lower, estimated at 5.84 mg/PCU, 29% less than in 2005 and 45% less than the peak that occurred in 2017. Conclusions The use of antimicrobials in food-producing animals in New Zealand is at the lowest rate for nearly 20 years, at 5.8 mg/PCU. Key progress has been made particularly by the poultry industry. Clear future areas to be targeted include prophylactic use of intramammary products applied when drying off dairy cows and a more widespread strategic use in treatment of clinical mastitis. Clinical relevance Veterinarians in New Zealand should leverage the significant reduction achieved in AMC by food-producing animals by continuing to improve strategies for antimicrobial use to further reduce the risk of antimicrobial resistance.

Immunomodulation and Humoral Immune Response in Teleost Immunized with Aeromonas-Derived Antigenic Extracellular Bioactive Molecules.

The common use of antimicrobials in food-animal production can lead to drug residues in edible tissues for consumers. However, immunomodulators enhance immune responses and vaccine effectiveness. A new perspective explores bacterial extracellular bioactive molecules (EBMs) in food-animal production to modulate host immune responses, potentially transforming pathogen management and antimicrobial use. This study investigates the immunogenic potential of Aeromonas hydrophila-derived EBMs (Antigens) to enhance the immune system. Four Antigens were administered intraperitoneally to Oreochromis niloticus (Nile Tilapia). Antigens 2 and Antigens 3 boosted fish immune competence within 21days. Remarkably, Antigens 3 induced robust immunity against A. hydrophila with a single dose, notably enhancing antibody-based immune responses. The increased antibody activity suggests Antigens 3 could be a vaccine candidate, promising further research and potential application in food-animal production to improve disease control. This study highlights immunomodulators' potential in reshaping disease management in the food-animal industry, emphasizing the benefits of focusing on bacterial EBMs to reduce reliance on antimicrobials and achieve sustainable disease prevention.

BlaTEM-positive Salmonella enterica serovars Agona and Derby are prevalent among food-producing animals in Chongqing, China.

Salmonella is one of the most important foodborne zoonotic pathogens, causing global morbidity and mortality in both humans and animals. Due to the extensive use of antimicrobials in food-producing animals, the antimicrobial resistance of Salmonella has attracted increasing attention globally. There have been many reports concerning the antimicrobial resistance of Salmonella from food-producing animals, meats and the environment. However, few studies on Salmonella from food-producing animals have been reported in Chongqing municipality, China. The aim of the present study was to determine the prevalence, serovar diversity, sequence types, and antimicrobial resistance of Salmonella isolated from livestock and poultry in Chongqing. Meanwhile, we also want to know the presence of β-lactamase genes, plasmid-mediated quinolone resistance (PMQR) genes and quinolone resistance-determining region (QRDR) mutations of Salmonella isolates. A total of 129 Salmonella strains were recovered from 2,500 fecal samples at 41 farms from pigs, goats, beef cattle, rabbits, chickens, and ducks. Fourteen serovars were identified, with S. Agona and S. Derby being the dominant serovars. The 129 isolates had high resistance to doxycycline (87.6%), ampicillin (80.6%), tetracycline (79.8%), trimethoprim (77.5%), florfenicol (76.7%) chloramphenicol (72.9%), and trimethoprim-sulfamethoxazole (71.3%), but were susceptible to cefepime. A total of 114 (88.4%) isolates showed multidrug resistant phenotypes. The prevalence of β-lactamase genes in Salmonella isolates was 89.9% (116/129), and among these isolates, 107 (82.9%) harbored blaTEM, followed by blaOXA (26, 20.2%), blaCTX-M (8, 6.2%), and blaCMY (3, 2.3%). In addition, qnrB, qnrD, qnrS, oqxA, oqxB, and aac(6')-Ib-cr were detected in 11, 2, 34, 34, 43, and 72 PMQR-producing isolates, respectively. Moreover, QRDR mutations were very common in PMQR-positive Salmonella isolates (97.2%, 70/72) with mutation(s) in parC or combinative mutations in gyrA and parC. More significantly, 32 extended spectrum beta-lactamase (ESBL)-producing isolates were identified, and 62.5% of them were found to harbor one to four PMQR genes. Furthermore, 11 sequence types were identified from the isolates, and most of ESBL-producing isolates were attributed to ST34 (15.6%) and ST40 (62.5%). The coexistence of PMQR genes with β-lactamase genes and the extensive mutations in QRDR present in Salmonella isolates from food-producing animals suggest a potential threat to public health. Reasonable utilization and strict control strategies for antimicrobials in animal husbandry and animal treatment are necessary to reduce the emergence and dissemination of drug-resistant Salmonella isolates.

Antimicrobial consumption in food-producing animals in Thailand between 2017 and 2019: The analysis of national importation and production data.

Antimicrobial resistance (AMR) threatens health security and the economy worldwide. AMR bacteria can spread across humans, animals, food webs and the environment. Excessive use of antimicrobials in food-producing animals has been recognised as one of the main drivers of the emergence of resistant bacteria. This study aims to quantify and identify patterns of antimicrobial consumption in food-producing animals in Thailand in a three-year period (2017-2019). Milligrams of active ingredient from total volume of imported and locally manufactured products minus exports were obtained from Thai FDA. Annual population production of food-producing animals in 2017, 2018 and 2019 was compiled and validated through cooperation between the Department of Livestock Development (DLD), Department of Fisheries (DOF). The total amount of antimicrobial consumption for food-producing animals decreased 49.0% over the three-year period from 658.7 mg/PCUThailand in 2017 to 336.3 mg/PCUThailand in 2019. In 2017, the most common antimicrobials used was macrolides which was replaced by aminopenicillins and pleuromutilins in 2019, while tetracyclines was consistently common over the three-year period. Consumption of the WHO Critically Important Antimicrobials (CIA) group declined significantly over this period, from 259.0 in 2017 to 193.2 mg/PCUThailand in 2019 (a 25.4% reduction). Findings from this study were in line with national policies which curtails prudent use of antimicrobials in food-producing animals. The government should maintain the decreasing trend of consumption, in particular of the CIA category. Improving information systems which captures consumption by specific species contributes to precision of interventions to minimise prudent use in each species.

Antimicrobial resistance in food-producing animals: towards implementing a one health based national action plan in Israel

BackgroundDevelopment of antimicrobial resistance poses a major threat to human and animal health worldwide. Antimicrobials are frequently used in animal husbandry, making food-producing animals a widespread and important source of antimicrobial resistance. Indeed, recent evidence demonstrates that antimicrobial resistance in food-producing animals poses a threat to the health of humans, animals and the environment. To address this threat, national action plans have been implemented based on a ‘One Health’ approach, which integrates actions across human and animal health sectors to combat antimicrobial resistance. Although under development, Israel has yet to publish a national action plan against antimicrobial resistance, despite alarming findings of resistant bacteria in food-producing animals in the country. Here we review several national action plans against antimicrobial resistance around the world in order to suggest approaches to develop a national action plan in Israel.Main bodyWe investigated worldwide national action plans against antimicrobial resistance based on a ‘One Health’ approach. We also conducted interviews with representatives of relevant Israeli ministries to understand antimicrobial resistance policy and regulatory frameworks in Israel. Finally, we present recommendations for Israel towards implementing a ‘One Health’ national action plan against antimicrobial resistance. Many countries have developed such plans, however, only a few are currently funded. Furthermore, many countries, especially in Europe, have taken action to reduce the use of antimicrobials and the spread of antimicrobial resistance in food-producing animals by banning the use of antimicrobials to promote growth, reporting data on the use and sales of antimicrobials in food-producing animals, operating centralized antimicrobial resistance surveillance systems and preventing the use of antimicrobials important to human medicine to treat food-producing animals.ConclusionsWithout a comprehensive and funded national action plan, the risks of antimicrobial resistance to the public health in Israel will escalate. Thus, several actions should be considered: (1) Reporting data on the use of antimicrobials in humans and animals. (2) Operating a centralized surveillance system for antimicrobial resistance in humans, animals and the environment. (3) Improving awareness regarding antimicrobial resistance in the general public and in health practitioners from both human and animal sectors. (4) Composing a list of critically important antimicrobials to human medicine that’s use should be avoided in food-producing animals. (5) Enforcing best practices of antimicrobial use at the farm-level. (6) Reducing incidence of infection through farm biosecurity. (7) Supporting research and development of new antimicrobial treatments, vaccines and diagnostic tools.

Antimicrobial resistance in fish and poultry: Public health implications for animal source food production in Nigeria, Egypt, and South Africa.

Antimicrobial resistance (AMR) is a significant threat to global public health. Specifically, excessive usage of antimicrobials in food animal production is one significant reason for AMR development in humans. Therefore, it is essential to identify the trends of AMR in fish and poultry and develop better surveillance strategies for the future. Despite this imperative need, such information is not well documented, especially in Africa. This study used a systematic review to assess AMR trend, spatial distribution, and incidence in fish and poultry research in Nigeria, Egypt, and South Africa. A literature assessment was conducted for published studies on AMR between 1989 and 2021 using the Scopus and Web of Science databases. One hundred and seventy-three relevant articles were obtained from the database search. Egypt was the leading exponent of antimicrobial resistance research (43.35%, 75 studies), followed by Nigeria (39.31%, 68 studies), then South Africa (17.34%, 30 studies). The majority of the antimicrobial resistance studies were on poultry in Egypt (81%, 61 studies), Nigeria (87%, 59 studies), and South Africa (80%, 24 studies). Studies on fish were 17% (13 studies), 9% (6 studies), and 10% (3 studies) in Egypt, Nigeria, and South Africa, respectively. Antimicrobial resistance patterns showed multiple drug resistance and variations in resistant genes. AMR research focused on sulfamethoxazole groups, chloramphenicol, trimethoprim, tetracycline, erythromycin, and ampicillin. Most studies employed the disk diffusion method for antimicrobial susceptibility tests. Among the four mechanisms of AMR, limiting drug uptake was the most reported in this study (both in fish and poultry). The findings reveal public and environmental health threats and suggest that it would be useful to promote and advance AMR research, particularly for countries on the global hotspot for antimicrobial use.

Swine enteric colibacillosis: Current treatment avenues and future directions.

Enteric colibacillosis is a common disease in nursing and weanling pigs. It is caused by the colonization of the small intestine by enterotoxigenic strains of Escherichia coli (ETEC) that make use of specific fimbria or pili to adhere to the absorptive epithelial cells of the jejunum and ileum. Once attached, and when both the immunological systems and the gut microbiota are poorly developed, ETEC produce one or more enterotoxins that can have local and, further on, systemic effects. These enterotoxins cause fluid and electrolytes to be secreted into the intestinal lumen of animals, which results in diarrhea, dehydration, and acidosis. From the diversity of control strategies, antibiotics and zinc oxide are the ones that have contributed more significantly to mitigating post-weaning diarrhea (PWD) economic losses. However, concerns about antibiotic resistance determined the restriction on the use of critically important antimicrobials in food-producing animals and the prohibition of their use as growth promoters. As such, it is important now to begin the transition from these preventive/control measures to other, more sustainable, approaches. This review provides a quick synopsis of the currently approved and available therapies for PWD treatment while presenting an overview of novel antimicrobial strategies that are being explored for the control and treatment of this infection, including, prebiotics, probiotics, synbiotics, organic acids, bacteriophages, spray-dried plasma, antibodies, phytogenic substances, antisense oligonucleotides, and aptamers.

Factors influencing usage of antimicrobial drugs among pastoralists in Kenya.

Agricultural use of antimicrobials in food animal production may contribute to the global emergence of antimicrobial resistance (AMR). However, considerable gaps exist in research on the use of antimicrobial drugs (AMDs) in food animals in small-scale production systems in low- and middle-income countries, despite the minimal regulation of antimicrobials in such regions. The aim of this study was to identify factors that may influence AMD use in livestock among pastoral communities in Kenya. We collected data related to household and herd demographics, herd health, and herd management from 55 households in the Maasai Mara ecosystem, Kenya, between 2018 and 2019. We used multi-model logistic regression inference (supervised machine learning) to ascertain trends in AMD use within these households. AMD use in cattle was significantly associated with AMD use in sheep and goats (p = 0.05), implying that decisions regarding AMD use in cattle or sheep and goats were interdependent. AMD use in sheep and goats was negatively associated with vaccination against the foot and mouth disease (FMD) virus in cattle (OR = 0.06, 95% CI 0.01-0.67, p = 0.02). Less AMD use was observed for vaccine-preventable diseases like contagious ecthyma when households had access to state veterinarians (OR = 0.06, p = 0.05, 95% CI 0.004-0.96). Overall, decisions to use AMDs were associated with vaccine usage, occurrence of respiratory diseases, and access to animal health advice. This hypothesis-generating study suggests that applying community-centric methods may be necessary to understand the use of AMDs in pastoral communities.

PREVALENCE OF ANTIMICROBIAL-RESISTANT ENTEROCOCCUS FAECIUM IN COMMERCIAL CATTLE: A SYSTEMATIC REVIEW AND META-ANALYSIS

The use of antimicrobials in animals is broader compared to humans, which can influence the increase in microbial resistance. This study was a systematic review which determined the prevalence of resistant Enterococcus faecium in commercial cattle. Eighteen studies were included, mainly carried out in European countries (n= 9) and in the production (n= 11) and retail (n= 7) environments. The main material used in the detection of the microorganism was milk. The mean prevalence of resistant E. faecium in cattle was 4.3% (95% CI= 2.8–5.0%), but the prevalence in Asia was higher [25.4% (95% CI= 20.5-30.6%)]. There was a higher prevalence in samples from retail (13.7%; 95% CI= 11.5-16.1%) and collected mainly from equipment surfaces (12.5%; 95% CI= 5.5-26.1%) than in the others tested samples. Antibiotics frequently tested were vancomycin, tetracycline, ciprofloxacin, and erythromycin, with resistance percentages of 50%, 59%, 79%, and 94%, respectively. These results reinforce the need to plan interventions to reduce antimicrobials in food-producing animals.

Antimicrobial Resistance and Livestock Trade for Low and Middle Income Countries: Regional Analysis of Global Coordination Policies

Antimicrobial resistance is a threat to global health, aggravated by the use of antimicrobials in livestock production. Mitigating the growing economic costs related to antimicrobial use in livestock production requires strong global coordination, and to that end policy makers can leverage global and national food animal trade policies, such as bans and user fees. Evaluation of such policies requires representing the interactions between competing producers in the global meat market, which is usually out of the scope of statistical models. For that, we developed a game-theoretic food system model of global livestock production and trade between 18 countries and aggregate world regions. The model comprises the largest producing and consuming countries, the explicit interconnections between countries, and the use of antimicrobials in food animal production. Our model allows us to provide policy insights beyond standard literature and assess the trade-off between trade, cost of a policy, and antimicrobials-induced productivity. We studied three scenarios: global increased user fees on antimicrobials, a global ban of meat imports from Brazil, and a decrease in China's meat consumption. We found that a user fee that increases the price of antimicrobials by 50% globally leads to a 33% reduction in global antimicrobial use. However, participation of developing and emerging countries in the coordination scheme is jeopardized, since they become less competitive for meat sales compared to developed countries. When meat imports from Brazil are banned globally, importers of Brazil's meat would turn primarily to the U.S. to supplement their demand. Lastly, meeting China's medium-term lower meat consumption target would not affect global antimicrobial use, but could increase China's antimicrobial use by 11%. We highlighted the importance of trade for the outcome of a policy and concluded that global cooperation is required to align the incentives of all countries toward tackling antimicrobial resistance.

Antimicrobial resistance of Salmonella from poultry meat in Brazil: results of a nationwide survey

Abstract The use of antimicrobials in food-producing animals can lead to increased bacterial resistance. Important information to address this problem can be provided by monitoring antimicrobial resistance (AMR) in foodborne pathogens. As part of preliminary activities for the implementation of AMR surveillance in Brazil, a nationwide survey on AMR in Salmonella enterica isolates from poultry meat was conducted. The survey evaluated 146 Salmonella isolates from poultry meat in 2014, and 163 isolates obtained in 2017. Minimal inhibitory concentrations of 13 antimicrobials were determined by broth microdilution, and isolates were assigned to serotypes by automated ribotyping. High resistance rates were found in 2014 and 2017, in particular to nalidixic acid (84/146, 57.5% and 141/163, 86.5%, respectively), ampicillin (82/146, 56.2% and 125/163, 76.7%), cefotaxime (76/146, 52.1% and 124/163, 76.1%), ceftazidime (73/146, 50.0% and 124/163, 76.1%), ciprofloxacin (83/146, 56.9% and 145/163, 89.0%) and tetracycline (88/146, 60.3% and 135/163, 82.8%). There was a significant increase in resistance to these antibiotics in the second survey period. Salmonella ser. Heidelberg and Salmonella ser. Minnesota were the main serotypes expressing resistance to these antimicrobials. Multidrug resistance was found in 50.7% (74/146) of the isolates from 2014, and in 77.3% (126/163) of isolates from 2017 (P < 0.05). None of the isolates was resistant to azithromycin or meropenem. These findings indicate high and increasing rates of resistance among Salmonella from poultry meat in Brazil, mainly associated with Salmonella ser. Heidelberg and Salmonella ser. Minnesota, stressing the importance of continuous monitoring of AMR in the poultry chain.

Prevalence of antimicrobial resistance genes and its association with restricted antimicrobial use in food-producing animals: a systematic review and meta-analysis.

There is ongoing debate regarding potential associations between restrictions of antimicrobial use and prevalence of antimicrobial resistance (AMR) in bacteria. To summarize the effects of interventions reducing antimicrobial use in food-producing animals on the prevalence of AMR genes (ARGs) in bacteria from animals and humans. We published a full systematic review of restrictions of antimicrobials in food-producing animals and their associations with AMR in bacteria. Herein, we focus on studies reporting on the association between restricted antimicrobial use and prevalence of ARGs. We used multilevel mixed-effects models and a semi-quantitative approach based on forest plots to summarize findings from studies. A positive effect of intervention [reduction in prevalence or number of ARGs in group(s) with restricted antimicrobial use] was reported from 29 studies for at least one ARG. We detected significant associations between a ban on avoparcin and diminished presence of the vanA gene in samples from animals and humans, whereas for the mecA gene, studies agreed on a positive effect of intervention in samples only from animals. Comparisons involving mcr-1, blaCTX-M, aadA2, vat(E), sul2, dfrA5, dfrA13, tet(E) and tet(P) indicated a reduced prevalence of genes in intervention groups. Conversely, no effects were detected for β-lactamases other than blaCTX-M and the remaining tet genes. The available body of scientific evidence supported that restricted use of antimicrobials in food animals was associated with an either lower or equal presence of ARGs in bacteria, with effects dependent on ARG, host species and restricted drug.

Determinants influencing antibiotic use in Singapore's small-scale aquaculture sectors: A qualitative study.

Singapore’s Antimicrobial Resistance (AMR) national strategic action plan includes inappropriate use of antimicrobials in food-producing animals as a specific priority. Although the use of antibiotics and other drugs are monitored by regulatory bodies, food fish farmers are allowed to buy and administer antimicrobials without a veterinary prescription. We conducted a qualitative study of Singaporean food fish farmers to understand patterns and determinants of antibiotic use, their knowledge of antibiotic resistance, as well as perceptions of on-farm infection prevention and control measures. During the interview, participants were asked about their farming processes, farm infrastructure, antibiotic use and any disease prevention measures. Thematic analysis of participants’ interviews showed that antibiotic for growth promotion and infection prevention was uncommon among local food fish farmers. The following three main themes influenced participants’ decisions to use antibiotics in their practice: 1) individual factors, 2) local regulatory factors as well as 3) market-related factors. Individual factors included their personal experience and knowledge both with antibiotics as well as with alternate options. In terms of local regulatory factors, we found that regular oversight was a strong deterrent in antibiotic use. Last, at the market level, the relatively high price of antibiotics in Singapore coupled with stiff competition was a strong disincentive for participants to use antibiotics in their farming practice. These factors were also influential in their relationships with local regulatory bodies as well as their counterparts. Although industries differ significantly across countries, lessons learnt from Singapore’s food fish farming demonstrate the importance of an environment where multi-dimensional factors come together to discourage the irrational use of antibiotics in food animal production. In addition, our results allow greater insight into food fish farmers’ perspectives on infection control and form a basis from which further research work can be undertaken.

Evaluation and quantification of antimicrobial residues and antimicrobial resistance genes in two Italian swine farms

Antimicrobial resistance genes (ARGs) are considered emerging environmental pollutants, posing potential risks for human and animal health: the misuse of antimicrobials in food-producing animals could favour the maintenance and spread of resistances in bacteria. The occurrence of ARGs in Italian swine farming – which has specific characteristics – was investigated in order to explore resistance spread dynamics. Two farrow-to-finish pig farms were longitudinally monitored: faecal samples from animals and environmental samples were collected. DNA was extracted and tetA, ermB, qnrS and mcr1 ARGs were analysed by qPCR for their ability to confer resistance to highly or critically important antimicrobials (CIAs). Moreover, 16SrDNA gene was analysed to assess bacterial abundance. ermB and tetA genes were found in animal samples and manure samples. On the contrary, mcr1 was exclusively found in weaners, while qnrS occurred in all animal categories but sows and finishers. Among the analysed genes, ermB and tetA showed the highest absolute and relative abundances. Our results indicate that ermB and tetA ARGs are widely disseminated in the explored farms, suggesting efficient maintenance among bacteria and persistence in the environment. Interestingly, the presence of qnrS and mcr1, limited to just a few animal categories, highlights inefficient dissemination of these genes in the farm environment, in particular for mcr1, a stable plasmid gene conferring resistance to the last-resort antimicrobial, colistin. Paying close attention only to the finishing phase would have hampered the discovery of resistances to CIAs at farm level, which we instead identified thanks to an intensive longitudinal monitoring programme.

Exploring Perspectives on Antimicrobial Use in Livestock: A Mixed-Methods Study of UK Pig Farmers.

Increasing levels of antimicrobial resistance in human and veterinary medicine have raised concerns over the irresponsible use of antimicrobials. The role of administering antimicrobials in food producing animals most frequently falls to the farmer, therefore it is essential that their use of antimicrobials is both optimal and responsible. This study sought in-depth information on the drivers behind antimicrobial use behaviors and farmer attitudes to responsible use using a mixed-methodological approach. Initially, in-depth semi-structured interviews were conducted with a purposively selected sample of farmers (n = 22). A thematic analysis approach was taken to identify key themes from these qualitative data. The generalizability and variation of these themes was then tested on a larger randomly selected sample of pig farmers through a questionnaire study (n = 261). The influences behind antimicrobial use were complex with multiple drivers motivating decisions. There was no consensual opinion on what farming systems resulted in either a low or high antimicrobial requirement however, farmers reported that good management practices, low stocking densities, and a high health status were associated with low antimicrobial use. Farmers expressed desire to avoid the long-term use of in-feed antimicrobials, but identified barriers to discontinuing such behaviors, such as pig morbidity, mortality, and economic losses. The high cost of antimicrobials was described as a motivation toward seeking alternative methods of controlling disease to prophylactic use; however, this expense was balanced against the losses from an increased burden of disease. The high financial costs involved in pig production alongside the economic uncertainty of production and pressure from retailers, were identified as limiting the scope for improvements in pig accommodation and facilities which could reduce the antimicrobial requirements on farm. Long-term, sustainable and economically stable relationships between retailers and farmers may allow farmers to make necessary investments in improving management and housing in order to reduce antimicrobial use. Greater use and more widespread deployment of effective vaccinations were highlighted by farmers as being a feasible alternative to antimicrobial use in preventing disease.

Perceptions of Tennessee cattle producers regarding the Veterinary Feed Directive.

Since January 1, 2017, the United States Food and Drug Administration (FDA) has fully implemented the Veterinary Feed Directive (VFD) final rule aimed at facilitating the judicious use of medically important antimicrobials in food-producing animals. The objective of this study was to identify the common perceptions of Tennessee (TN) cattle producers regarding the VFD. We used a combination of focus groups and survey questionnaires to explore TN cattle producers’ perceptions regarding the VFD. Preliminary findings from seven focus groups of 62 producers were used in the development of the questionnaire sent both online and in-print to rest of cattle producers in TN. The beef focus group participants perceived the VFD: to be a top-down policy; to have led to unregulated access to in-feed antimicrobials; a regulation that has limited the producers’ ability to prevent disease and leading to economic losses; to negatively affect small producers; and to be affected by challenges related to prescription writing and disposal of un-used medicines. The dairy focus group participants perceived the VFD as unnecessary and burdensome, to have affected small producers, and introduced additional costs. Among the survey questionnaire respondents, 35 (15.4%) beef producers and 6 (13.6%) dairy producers respectively were not familiar at all with the VFD. Forty-eight (21.1%) beef producers and 11 (25%) dairy producers were slightly familiar with VFD. Gender was significantly associated (P = 0.02) with the beef producers’ belief in the usefulness of the VFD. Similarly, for dairy producers, herd size was significantly associated (P = 0.002) with their perceptions regarding the usefulness of the VFD. The findings of this study could inform future VFD policy review processes. More awareness regarding the VFD and its benefits is needed among both beef and dairy producers in TN.

Antimicrobial drug usage from birth to 180 days of age in Irish dairy calves and in suckler beef calves

ABSTRACT Concern about the use of antimicrobials in food producing animals is increasing. The study objective was to quantify antimicrobial drug usage in calves using antimicrobial treatment records from Irish suckler beef and dairy farms. Antimicrobial treatment records for calves born between 1 July 2014 and 30 June 2015 on 79 suckler beef and 44 dairy farms were analyzed. Calves were followed from birth (day 0) until 6 months of age. According to standard farm protocol, calves exhibiting clinical signs of any disease were identified and antimicrobial treatment was administered. Farmers recorded the following information for each treatment administered: calf identification, age at treatment, disease event, drug name, number of treatment days, and amount of drug administered. In total, 3,204 suckler beef calves and 5,358 dairy calves, representing 540,953 and 579,997 calf-days at risk, respectively, were included in the study. A total of 1,770 antimicrobial treatments were administered to suckler beef (n = 841) and dairy calves (n = 929) between birth and 6 months of age. There was large variation in TIDDDvet and TIDCDvet by farm. This study provides new insights into the time periods and indications for which specific antimicrobial substances are used in Irish dairy and beef suckler calves.

Antimicrobial Resistance: a One Health Perspective.

One Health is the collaborative effort of multiple health science professions to attain optimal health for people, domestic animals, wildlife, plants, and our environment. The drivers of antimicrobial resistance include antimicrobial use and abuse in human, animal, and environmental sectors and the spread of resistant bacteria and resistance determinants within and between these sectors and around the globe. Most of the classes of antimicrobials used to treat bacterial infections in humans are also used in animals. Given the important and interdependent human, animal, and environmental dimensions of antimicrobial resistance, it is logical to take a One Health approach when addressing this problem. This includes taking steps to preserve the continued effectiveness of existing antimicrobials by eliminating their inappropriate use and by limiting the spread of infection. Major concerns in the animal health and agriculture sectors are mass medication of animals with antimicrobials that are critically important for humans, such as third-generation cephalosporins and fluoroquinolones, and the long-term, in-feed use of medically important antimicrobials, such as colistin, tetracyclines, and macrolides, for growth promotion. In the human sector it is essential to prevent infections, reduce over-prescribing of antimicrobials, improve sanitation, and improve hygiene and infection control. Pollution from inadequate treatment of industrial, residential, and farm waste is expanding the resistome in the environment. Numerous countries and several international agencies have included a One Health approach within their action plans to address antimicrobial resistance. Necessary actions include improvements in antimicrobial use regulation and policy, surveillance, stewardship, infection control, sanitation, animal husbandry, and alternatives to antimicrobials. WHO recently has launched new guidelines on the use of medically important antimicrobials in food-producing animals, recommending that farmers and the food industry stop using antimicrobials routinely to promote growth and prevent disease in healthy animals. These guidelines aim to help preserve the effectiveness of antimicrobials that are important for human medicine by reducing their use in animals.