Antimicrobial Use and Stewardship
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Resources & Outreach
The AUS program provides resources for all stakeholders, including veterinarians and producers, about the effort in California to reduce antimicrobial resistance in livestock. Below please find outreach and educational materials, best management practices and guidance documents, programmatic reports, and other publications produced or supported by the AUS program. Information on AUS presentations and events, past and upcoming, is also provided. Additionally, other resources related to antimicrobial resistance education and research are listed.
Frequently Asked Questions:
Answers to frequently asked questions regarding the AUS program.
Requirements for Prescription Antibiotics:
Existing requirements for veterinary prescriptions, options for filling prescriptions, and establishing a valid veterinarian-client-patient relationship (VCPR).
Veterinarian | Producer | Spanish (Español: Requisitos para Antibióticos Recetados)
AUS Annual Reports: Description and highlights of program activities reported for each fiscal year. Attached appendices provide more detailed information for a selection of AUS' studies and projects.
Veterinary Feed Directive (VFD) Summary Reports: Annual summaries of manufacturing and distribution data for California medicated feed containing a VFD drug or combination VFD drugs, by VFD order written by a licensed veterinarian.
AUS Report to the Legislature: The AUS Report to the Legislature, published in 2019, fulfills the mandate in FAC 14405 (d) by providing the results of the program’s outreach activities and monitoring efforts during its first years of implementation.
AUS Strategic Plans: AUS publishes its Strategic Plans as appropriate to update stakeholders on programmatic goals and plans for implementation.
CDFA AUS – Best Management Practices (BMPs) // Vaccine Handling Guidelines: Five infographics providing foundational knowledge of proper vaccine handling to ensure an effective vaccination program.
CDFA AUS – Best Management Practices (BMPs) // Vaccine Handling Guidelines – Resources for Veterinarians: These veterinary considerations offer a more in-depth instruction on the nuances of creating an effective vaccination program, along with additional scientific resources.
These cow calf guidelines provide direction for producers and veterinarians to assist with the detection, prevention and management of the top three diseases that can lead to antibiotic use in cow calf operations: pinkeye, scours and bovine respiratory disease.
The documents titled Strategies for Management are infographic documents designed for producers. The documents titled Practical Guide for Veterinarians are to be used by veterinarians in addition to the infographic guidelines.
Pinkeye
- Cow Calf Pinkeye: Strategies for Management | Español: Conjuntivitis bovina: Estrategias de manejo
- Pinkeye Management in Cow Calf Operations: A Practical Guide for Veterinarians
Scours
- Cow Calf Scours: Strategies for Management | Español: Diarrea neonatal de los terneros: Estrategias de manejo
- Prevention of Neonatal Calf Diarrhea in Cow Calf Operations: A Practical Guide for Veterinarians
Bovine Respiratory Disease
Antimicrobial Stewardship Principles: Please visit the AUS Antimicrobial Stewardship page.
Guidelines for Judicious Use of Antimicrobials: These guidelines are intended to support decision-making surrounding responsible antibiotic use, under the guidance of a veterinarian in compliance with state and federal laws.
Antimicrobial Stewardship Planning Checklist: Resources to promote or support veterinarians engaging in conversations with their livestock producers regarding broad, non–species specific health related topics.
- Antimicrobial Stewardship Planning Checklist One–Page | Español: Lista de verificación para la planificación de administración de antimicrobianos de una página
- Antimicrobial Stewardship Planning Checklist Workbook | Español: Cuaderno de trabajo de la lista de verificación para la planificación de administración de antimicrobianos
Veterinarian–Client–Patient Relationship (VCPR) Resources: Establishing a veterinarian–client–patient relationship (VCPR) is an essential first step in the development of an Antimicrobial Stewardship Plan.
Antimicrobial Selection: Considerations for Veterinarians : This guide provides an overview of concepts to consider when using antimicrobial susceptibility test data to guide clinical decisions.
These cattle-specific fly identification, monitoring, and tracking resources support producers in identification/monitoring of common cattle fly pests, as well as provide the framework for development and evaluation of on-farm pest management plans. The Fly Identification, Monitoring, and Tracking Resource specifically provides a comprehensive overview of cattle fly pest management, with species-specific information and infographics, monitoring guidelines, and resources for pest management strategies.
- Fly Identification, Monitoring, and Tracking Resource
- Fly Identification: General Monitoring Worksheet
- Fly Identification: Species Monitoring and Abundance Graph Worksheet
- Fly Identification: Strategy Tracker Worksheet
- Fly Identification: Species Monitoring and Abundance Graph Interactive Excel Worksheet
2019 NAHMS Goat Study – CA Results: Summary results from USDA NAHMS' 2019 two-phase study of antibiotic use and stewardship in California's goat operations. CDFA provided funding to expand Phase I and provided personnel to conduct Phase II.
2017 Cow Calf Survey: Summary findings from AUS’ 2017 survey of antibiotic use and stewardship on California’s cow calf operations.
2018 Commercial Sheep Survey: Summary findings from AUS’ 2018 survey of antibiotic use and stewardship on California’s commercial sheep operations.
2018 Commercial Sheep Survey | Español: Encuesta de Ovejas Comerciales 2018
Veterinary Feed Directive (VFD) Resources: Resources related to VFDs and VFD orders. For more information on VFDs, please visit the CDFA FFLDRS Livestock Drug Program page.
Confidentiality in Data Reporting: Brochure with information on AUS’ approach to confidentiality in data reporting.
AUS Surveys & Studies Resources: Materials addressing the who, what, why, and how the AUS program is collecting information on California animal agriculture and what you can do to help. For more information on AUS Surveys & Studies, please visit the Surveys & Studies page.
Antimicrobial Stewardship During COVID-19 Pandemic: COVID-19 has brought numerous challenges to the animal production industry. This infographic lists considerations for the continuation of antimicrobial stewardship in livestock during the COVID-19 pandemic.
In addition to materials, events, and research produced by the AUS team, the AUS program provides funding and support for a number of studies, projects, publications, and other resources led by external partners. Below find information on work produced with AUS funding and/or collaborative support.
Please Note: The New flag indicates publications new to this list, not necessarily chronological in time for work performed or publication date. To facilitate searching for subjects of interest, keywords have been provided for each publication.
Abdelfattah EM, Ekong PS, Okello E, Chamchoy T, Karle BM, Black RA, Sheedy D, ElAshmawy WR, Williams DR, Califano D, Tovar LF. Epidemiology of antimicrobial resistance (AMR) on California dairies: descriptive and cluster analyses of AMR phenotype of fecal commensal bacteria isolated from adult cows. PeerJ. 2021;9. https://peerj.com/articles/11108/
This study describes the occurrence of antibiotic resistance in commensal Escherichia coli and Enterococcus/ Streptococcus spp. isolated from fecal samples of dairy cows and assesses the variation in antibiotic resistance profiles across regions and seasons following the implementation of the Food and Agricultural Code (FAC) Sections 14400 - 14408 (formerly known as Senate Bill, SB 27) in California.
Keywords: antimicrobial resistance; dairy cattle; Escherichia coli, Enterococcus spp; multidrug resistance, phenotype; California; region; season; cohort study
Abdelfattah EM, Ekong PS, Okello E, Williams DR, Karle BM, Rowe JD, Marshall ES, Lehenbauer TW, Aly SS. 2019 Survey of Antimicrobial Drug Use and Stewardship Practices in Adult Cows on California Dairies: Post Senate Bill 27. Microorganisms. 2021 Jul;9(7):1507.507. https://doi.org/10.3390/microorganisms9071507
In this project, surveys were sent out to 1282 California dairies in both 2018 and 2019 to determine and evaluate changes in antibiotic use, health management, and antibiotic drug stewardship practices of adult cows on California dairies following the initiation of implementation of California Food and Agriculture Code 14400 - 14408 (formerly SB 27).
Keywords: antimicrobial drug resistance; antimicrobial stewardship; California; dairy cattle; judicious use; survey
Basbas C, Byrne BA, Chigerwe M, Escobar ED, Hodzic E, Pires AF, Pereira RV. Detection of Cephalosporin and Fluoroquinolone Resistance Genes via Novel Multiplex qPCR in Fecal Salmonella Isolates From Northern Californian Dairy Cattle, 2002 - 2016. Frontiers in Microbiology. 2021;12. https://doi.org/10.3389/fmicb.2021.601924
In this study, Salmonella isolates obtained from dairy cattle were screened for beta-lactam resistance genes, focusing on genes linked to resistance to cephalosporin drugs, and quinolone resistance genes. Testing included whole genome studies focusing on isolates resistant to quinolones to identify potential chromosomal mutations leading to resistance to quinolone drugs. Temporal distribution of genetic elements was evaluated for links to antibiotic resistance, as well as potential trends or factors that could have influenced changes in their prevalence.
Keywords: fluoroquinolone; cephalosporin; qPCR; antimicrobial resistance genes; Salmonella
New Bernal-Córdoba, C., Branco-Lopes, R., Latorre-Segura, L., de Barros-Abreu, M., Fausak, E.D., and Silva-del-Río, N. (2022). Use of antimicrobials in the treatment of calf diarrhea: a systematic review. Animal Health Research Reviews 23, no. 2: 101-12. https://doi.org/10.1017/S1466252322000032
The objective of this study was to conduct a systematic review of the scientific literature evaluating the efficacy and comparative efficacy of antimicrobials for the treatment of diarrhea in calves. Eligible studies were non- and randomized controlled trials evaluating an antimicrobial intervention against a positive and negative control, with at least one of the following outcomes: fecal consistency score, fever, dehydration, appetite, attitude, weight gain, and mortality. The results reveal few studies evaluating the efficacy of antimicrobials for the calf diarrhea treatment, thus a metaanalysis can not be conducted.
Keywords: antimicrobials, calf diarrhea, systematic review
Chen, S.-Y.; Negri Bernardino, P.; Fausak, E.; Van Noord, M.; Maier, G. (2022) Scoping Review on Risk Factors and Methods for the Prevention of Bovine Respiratory Disease Applicable to Cow-Calf Operations. Animals, 12, 334. https://doi.org/10.3390/ani12030334
https://www.mdpi.com/2076-2615/12/3/334
This scoping review summarizes the English scientific literature on articles about risk factors for the disease as well as ways to prevent bovine respiratory disease (BRD) that are applicable to cow-calf operations. Numerous management and animal factors have been identified as increasing the risk for BRD. Vaccinations, metaphylactic use of antibiotics, and feed supplements are areas of research into the prevention of BRD. Genetics have also been explored to determine the heritability of BRD resistance. While vaccinations and metaphylactic use of antibiotics have been evaluated in multiple systematic reviews and meta-analyses, these types of summaries are missing for commonly studied feed supplements, such as yeast and trace minerals, and the use of nitric oxide releasing substance to prevent BRD.
Keywords: bovine respiratory disease, prevention, risk factors, antimicrobial stewardship, shipping fever
Depenbrock S, Aly S, Wenz J, Williams D, ElAshmawy W, Clothier K, Fritz H, McArthur G, Heller M, Chigerwe M. In-vitro antibiotic resistance phenotypes of respiratory and enteric bacterial isolates from weaned dairy heifers in California. PLoS One. 2021 Nov 24;16(11):e0260292. doi: 10.1371/journal.pone.0260292. PMID: 34818352; PMCID: PMC8612539. https://pubmed.ncbi.nlm.nih.gov/34818352/
This study aimed to provide data from weaned dairy heifers regarding antimicrobial resistance in bovine respiratory isolates and identify relationships between respiratory and enteric antimicrobial drug susceptibility. A cross-sectional study was performed between June 2019 and February 2020 on six calf rearing facilities in California. Deep nasopharyngeal and rectal swabs were collected from 341 weaned heifers and submitted for selective bacterial culture and antimicrobial susceptibility testing against 19 antimicrobial drugs. Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni were selectively isolated from respiratory samples; Escherichia coli and Enterococcus spp. were selectively isolated from rectal swabs. Antimicrobial resistance (AMR), including multidrug resistance, in respiratory isolates appears to be widespread in weaned dairy heifers; enteric bacterial susceptibility appears to have limited direct association with respiratory isolate AMR classification.
Keywords: antimicrobial resistance; bovine; dairy; heifers; MIC; respiratory; Mannheimia haemolytica; Pastuerella multocida; Entrerococcus; Escherichia coli; bacterial pathogens; cattle; enteric; California; BRD
Ekong PS, Abdelfattah EM, Okello E, Williams DR, Lehenbauer TW, Karle BM, Rowe JD, Aly SS. 2018 Survey of factors associated with antimicrobial drug use and stewardship practices in adult cows on conventional California dairies: immediate post-Senate Bill 27 impact. PeerJ. 2021 Jul 13;9:e11596. https://peerj.com/articles/11596/
This project examined good antibiotic drug stewardship practices on conventional dairies in California using survey data from 2018 that was previously described in another publication. The authors applied machine learning to model the associations between management practices and seven outcome variables relating to antibiotic use and stewardship.
Keywords: California dairy industry; antimicrobial drug use; antimicrobial stewardship; judicious use of antibiotics; risk factors; logistic regression; machine learning; decision tree; random forest; gradient boosting
Ekong PS, Abdelfattah EM, Okello E, Williams DR, Lehenbauer TW, Karle BM, Rowe JD, Marshall ES, Aly SS. 2018 Survey of antimicrobial drug use and stewardship practices in adult cows on California dairies: post-Senate Bill 27. PeerJ. 2021 Jul 13;9:e11515. https://peerj.com/articles/11515.pdf
In this project, surveys were sent out to 1282 California dairies in both 2018 and 2019 to determine and evaluate changes in antibiotic use, health management, and antibiotic drug stewardship practices of adult cows on California dairies following the initiation of implementation of California Food and Agriculture Code 14400 - 14408 (formerly SB 27).
Keywords: California dairy industry survey; antimicrobial resistance; antimicrobial stewardship; antimicrobial drugs (AMD); judicious use of AMD
New Ferreira, F. C., Martínez-López, B., and Okello, E. (2022). Potential impacts to antibiotics use around the dry period if selective dry cow therapy is adopted by dairy herds: An example of the western US. Preventive Veterinary Medicine, Volume 206, 105709, ISSN 0167-5877. https://doi.org/10.1016/j.prevetmed.2022.105709
Objectives in this cross-sectional study were to estimate the potential reduction in the use of antimicrobials if selective dry cow therapy (SDCT) was adopted in the United States by using cow-level dairy herd data and to describe the factors associated with cows being classified as high-risk for an intramammary infection at dry-off. Cow-level somatic cell score (SCS) test-day data from herds in the western United States was used to create five scenarios to classify cows as high risk for intramammary infection at dry-off. Associations between cow-level data and state were also used in logistic regression models. Calculations of the average animal-defined daily dosage of antimicrobials per cow per year around the dry period if a blanket dry cow therapy (BDCT) or SDCT approach is used, adjusting for the risk of cases of clinical mastitis in the next lactation for the SDCT approach. By extrapolating the results obtained from using data from dairies enrolled in the testing program for the western United States, it was demonstrated that, regardless of the criteria used to classify cows as high risk of intramammary infection at dry-off (scenarios 1 - 5), if selective dry cow therapy is adopted in the United States, the dairy industry could reduce the use of antimicrobials around the dry-off between 31% and 66%.
Keywords: selective dry cow therapy, intramammary infection, dry-off, antimicrobial use
New
Fritz, H. M., Pereira, R. V., Toohey-Kurth, K., Marshall, E., Tucker, J., and Clothier, K. A. (2022). Salmonella enterica serovar Dublin from cattle in California from 1993-2019: antimicrobial resistance trends of clinical relevance. Antibiotics 11, no. 8: 1110. https://doi.org/10.3390/antibiotics11081110
https://www.mdpi.com/2079-6382/11/8/1110
Salmonella enterica subsp. enterica serovar Dublin (S. Dublin) is a cattle-adapted pathogen that has emerged as one of the most commonly isolated and multidrug resistant (MDR) serovars in cattle. Though infections with S. Dublin in humans are rare, they are frequently severe, with extraintestinal spread that requires hospitalization and antimicrobial therapy. To determine minimum inhibitory concentration (MIC) and antimicrobial resistance (AMR) patterns and trends in cattle in California, broth microdilution testing was performed on 247 clinical S. Dublin isolates recovered from cattle at the California Animal Health and Food Safety Laboratory System (CAHFS) over the last three decades (1993 - 2019). Findings indicate an increase in AMR for the years 1993 to 2015. Notably, compared to the baseline year interval (1993 - 1999), there was an increase in resistance among quinolone and cephalosporin drugs, as well as an increased number of isolates with an MDR profile.
Keywords: Salmonella enterica serovar Dublin, cattle, antimicrobial resistance, trends, antimicrobial susceptibility testing, MIC
New Garzon, A., Hoyos-Jaramillo, A., Hustad, S., Byrne, B. A., Fritz, H. M., Lehenbauer, T. W., Aly, S., and Pereira, R. (2023). In vitro evaluation of the effect of transport medium, temperature, and time on the recovery of Mannheimia haemolytica and Pasteurella multocida. JDS Communications, Short Communication: Health, Behavior, and Well-being, Volume 4, pgs 214-218. https://www.jdscommun.org/article/S2666-9102(23)00010-8/fulltext
Microbiological diagnosis is an important step in controlling and preventing bovine respiratory disease. Adequate sample transport medium, elapsed time, and storage temperature before laboratory submission are critical for optimal results. The objective was to evaluate the effect of transport storage medium, time, and storage temperature on Mannheimia haemolytica (MH) and Pasteurella multocida (PM) yield using an in-vitro model simulation. The results support the use of Aimes culture media with charcoal and Cary-Blair transport Agar for increasing recovery of PM and MH in samples, especially when samples are exposed to high temperatures during transport and longer intervals from collection to diagnostic evaluation. The combination of longer elapsed time and higher temperatures can impair diagnostic accuracy in detecting PM and MH from swabs.
Keywords: Mannheimia haemolytica, Pasteurella multocida, transport media, bovine respiratory disease, cattle
An article published in the publication Progressive Dairy promoting an AUS funded study that explores the use of Selective Dry Cow Therapy in dairy herds and the opportunity to reduce the use of antibiotics in dairy production systems, which may also be an economic opportunity for dairy farmers.
Hommels NM, Ferreira FC, van den Borne BH, Hogeveen HT. Antibiotic use and potential economic impact of implementing selective dry cow therapy in large U.S. dairies. Journal of Dairy Science. 2021 Apr 30. https://doi.org/10.3168/jds.2020-20016
In this study, the objectives were to evaluate the economic feasibility of implementing selective dry cow therapy (SDCT) in large U.S. dairy herds and to estimate the potential reduction in antibiotic use around the dry period if SDCT management is adopted. Cow-level data were obtained from the Dairy Herd Improvement Association and individual dairy herds in California. Logistic regression models were used to predict the incidence risk of subclinical and clinical mastitis in the subsequent lactation for 96 last test-day somatic cell score categories. This study showed that it is economically feasible on some farms to reduce antibiotic use associated with dry cow therapy in large U.S. dairy herds. This contributes to the efforts of reducing antibiotic use worldwide.
Keywords: selective dry cow therapy; antibiotic use; economics; optimization
New Latack, B. C., Carvalho, P. H. V., and Zinn, R. A. (2022). The interaction of feeding an eubiotic blend of essential oils plus 25-hydroxy-vit-D3 on performance, carcass characteristics, and dietary energetics of calf-fed Holstein steers. Frontiers in Veterinary Science, Volume 9. https://www.frontiersin.org/articles/10.3389/fvets.2022.1032532
Bans on ionophores in several regions of the world have led to a need to identify alternative feed additives to support feed efficiency in cattle. Essential oil blends have been identified as a potential alternative to ionophores in feedlot diets. This study evaluated the effects of a supplemental blend of essential oils and 25-hydroxyvitamin D3 on growth performance, energetic efficiency, and carcass characteristics in calf-fed Holstein steers. Ninety Holstein steer calves (123 ± 7 kg; 4 months old) were randomly assigned to 18 pens (5 steers/pen; 6 pens/treatment). Dietary treatments consisted of a steam-flaked corn-based diet supplemented with (DM basis): (1) no additives (CON); (2) 30 mg/kg of monensin (MON); (3) 200 mg/kg mixture of essential oils plus 25-hydroxyvitamin D3 (EO+HYD). There were no treatment effects (P > 0.05) on initial, intermediate, and final cattle live weight; moreover, cattle had similar average daily gain (ADG) and dry matter intake (DMI) among dietary treatments. Study results suggest that supplementing calf-fed Holstein steer diets with MON or EO+HYD for over 285 days increases dietary net energy utilization for maintenance and gain by 3 and 4%, respectively.
Keywords: cattle, ionophores, monensin, antibiotic alternative
New Lee, K., Pereira, R.V., Martínez-López, B., Busch, R.C., and Pires, A.F.A. (2022). Assessment of the knowledge and behavior of backyard and small-scale producers in California regarding disease prevention, biosecurity practices and antibiotics use. PLoS ONE 17(11): e0277897. https://doi.org/10.1371/journal.pone.0277897
The number and popularity of backyard poultry and livestock farming have rapidly increased in California and other states in the United States, following consumers’ preference for local and organic products in the last few years. This study aimed to investigate current on-farm management and farmers’ understanding of the Veterinary Feed Directive (VFD) and California Senate Bill 27 (SB 27) implications for disease prevention, biosecurity procedures, and antimicrobial use in small-scale and backyard farms in California. The survey consisted of 38 questions. The responses of 242 backyard and small-scale livestock owners were investigated in this study. Descriptive statistics summarized survey responses, and multivariable logistic regression evaluated the association of antibiotics purchase and use, and the impact of VFD and SB 27 on antibiotic use with demographics and on-farm management. Backyard and small-scale farmers in California mostly raised chickens or small ruminants with small herd sizes kept for personal use. Antibiotics were generally used for individual treatment of a sick animal with the guidance of a veterinarian. VFD and SB 27 implementation promoted the judicious use of antibiotics, specifically, by enhancing the relationship between backyard and small-scale farmers with veterinarians and treating fewer animals with antibiotics under veterinary oversight. Therefore, better access to veterinary services in backyard and small-scale farms will improve the farmer’s knowledge of good husbandry practices with judicious antimicrobial use in livestock and finally contribute to reducing the risk of antimicrobial resistance in California.
Keywords: backyard livestock producers, antimicrobial use, biosecurity, disease prevention, SB 27, veterinary feed directives
Maier, G, Breitenbuecher J, Gomez JP, Samah F, Fausak E, Van Noord M (2022). Vaccination for the Prevention of Neonatal Calf Diarrhea in Cow-Calf Operations: A Scoping Review. Veterinary and Animal Science, Volume 15: 100238, ISSN 2451-943X, https://doi.org/10.1016/j.vas.2022.100238. https://www.sciencedirect.com/science/article/pii/S2451943X22000096
Neonatal calf diarrhea (NCD), also known as scours, is an important disease of preweaned calves that affects the production and welfare of beef herds. While hygiene and nutrition are important in reducing the incidence of NCD, vaccination of dams or calves is often employed for the prevention of NCD. This scoping review summarizes the available peer-reviewed scientific English literature on vaccination of dams or calves for the prevention of NCD over the past decades. In the 113 articles included in the review, vaccines tested targeted the pathogens E. coli (n = 43), bovine rotavirus (BRV, n = 38), Salmonella (n = 29), bovine coronavirus (BCV, n = 14), bovine viral diarrhea virus (n= 7), and other pathogens (n = 8). Field trials for commercial vaccines have been published for the most important pathogens, and results on efficacy are variable for such vaccines targeting BRV, BCV, and E. coli. Meta-analyses exploring efficacy of these vaccines would be helpful to practitioners and producers. No field studies on commercial products have shown efficacy for Salmonella vaccines, so that a meta-analysis would unlikely come to a different conclusion. Further research is needed on vaccines for protozoal pathogens like Cryptosporidium parvum as well as on the importance of several emerging enteric viruses in calves.
Keywords: calf scours, diarrhea, enteritis, vaccine
Michael A, Kelman T, Pitesky M. Overview of quantitative methodologies to understand antimicrobial resistance via minimum inhibitory concentration. Animals. 2020 Aug;10(8):1405. https://doi.org/10.3390/ani10081405
Minimum Inhibitory Concentration (MIC) testing is a common method of measuring the susceptibility of bacteria to antibiotic drugs. Several quantitative techniques exist for analyzing MIC data, but the application of these methods is not consistent across studies and no guidelines exist for how to choose the most appropriate method. The purpose of this paper is to outline important considerations for selecting the appropriate analytic method to use with MIC data based on the purpose and context of the study.
Keywords: MIC; AMR; mixed effect models; logistic regression; cumulative logistic regression; accelerated failure time-frailty models; mixture models
Morgan, B L, Depenbrock, S, Martinez-Lopez, B. Identifying Associations in Minimum Inhibitory Concentration Values of Escherichia coli Samples Obtained from Weaned Dairy Heifers in California using Bayesian Network Analysis. (2022) Frontiers in Veterinary Science, Vol. 9, ISSN: 2297-1769. https://doi.org/10.3389/fvets.2022.771841. https://www.frontiersin.org/articles/10.3389/fvets.2022.771841/full
Many antimicrobial resistance studies in both human and veterinary medicine use traditional statistical methods that consider one bacteria and one antibiotic match at a time. A more robust analysis of antimicrobial resistance patterns in groups of animals is needed to improve on traditional methods examining antibiotic resistance profiles, or the associations between the patterns of resistance or reduced susceptibility for all isolates in an investigation. The use of Bayesian network analysis can identify associations between distributions; this investigation seeks to add to the growing body of antimicrobial resistance pattern research by using Bayesian networks to identify relationships between susceptibility patterns in Escherichia coli isolates obtained from weaned dairy heifers in California.
Keywords: bovine, Bayesian Network Analysis, minimum inhibitory concentration, antibiotics, antimicrobial resistance
Okello E, Williams DR, ElAshmawy WR, Adams J, Pereira RV, Lehenbauer TW, Aly SS. Survey on antimicrobial drug use practices in California preweaned dairy calves. Frontiers in Veterinary Science. 2021;8. https://doi.org/10.3389/fvets.2021.636670
This survey allows immediate assessment of the impact of VFD final rule implementation and provides baseline data for future evaluation of the impact of VFD as well as SB 27 regulatory changes. The knowledge gained from this study is a valuable resource that could guide future recommendations for best health management practices and promote antibiotic stewardship efforts.
Keywords: antimicrobial drug use; veterinary feed directive; perception; preweaned dairy calves; California Senate Bill 27
Sheedy DB, Okello E, Williams DR, Precht K, Cella E, Lehenbauer TW, Aly SS. Effect of Antimicrobial Treatment on the Dynamics of Ceftiofur Resistance in Enterobacteriaceae from Adult California Dairy Cows. Microorganisms. 2021 Apr;9(4):828. https://doi.org/10.3390/microorganisms9040828
This study investigates the time to peak population and time to return to pre-treatment population of phenotypically ceftiofur-resistant enteric commensal bacteria in response to systemic antibiotic treatment, in commercial dairy cows during the first 60 days of lactation, on two California dairies each across two seasons.
Keywords: antimicrobial resistance; ceftiofur; medically important antimicrobial drugs; dairy; minimum inhibitory concentration
Sheedy DB, Samah FE, Garzon A, Fausak E, Van Noord M, Angelos JA, Maier GU. Non-antimicrobial approaches for the prevention or treatment of infectious bovine keratoconjunctivitis in cattle applicable to cow-calf operations: A scoping review. Animal. 2021 Jun 1;15(6):100245. https://www.sciencedirect.com/science/article/pii/S1751731121000872
Findings of the AUS 2017 Cow Calf Survey of California producers showed that pinkeye was one of the top three diseases of concern in this livestock population. In response, AUS funded a study to further explore options for producers to reduce the burden of this disease. In this scoping review, various non-antibiotic options for management of pinkeye were explored, resulting in the determination that further research is needed on the efficacy of fly control, and on non-antibiotic treatment options such as topical disinfectants or immune stimulants. The continued search for a viable vaccine, as well as identifying genetic markers associated with traits that confer resistance to the disease, are also needed.
Keywords: breed susceptibility; fly control; Moraxella bovis; pinkeye; vaccine
New Wright, A., Li, X., Yang, X., Soto, E., and Gross, J. (2023). Disease prevention and mitigation in US finfish aquaculture: A review of current approaches and new strategies. Reviews in Aquaculture. 2023;1-16. https://onlinelibrary.wiley.com/doi/10.1111/raq.12807
This review discusses how various strategies used by the aquaculture industry contribute to the overall protection of fish from pathogens in the aquaculture industries. In the era of antimicrobial resistance, this review also highlights current and emerging alternative strategies that do not rely on traditional antimicrobial products (e.g., vaccines, dietary supplements, novel antimicrobials, stock selection) for disease prevention and mitigation.
Keywords: antimicrobial resistance, aquaculture, disease management, immunocompetence
FARM Everyday Biosecurity Reference Manual: Farmers Assuring Responsible Management (FARM) has released a manual that includes management practices designed to protect cattle and people from disease exposure, which can in turn reduce antimicrobial use. The Everyday Biosecurity Manual provides you with the steps to get started and build additional protections for your cattle.