Antibiotics in Dairy Production: Where Is the Problem?

Antibiotics have long been used for the prevention and treatment of common diseases and for prophylactic purposes in dairy animals. However, in recent decades it has become a matter of concern due to the widespread belief that there has been an abuse or misuse of these drugs in animals and that this misuse has led to the presence of residues in derived foods, such as milk and dairy products. Therefore, this review aims to compile the scientific literature published to date on the presence of antibiotic residues in these products worldwide. The focus is on the reasons that lead to their presence in food, on the potential problems caused by residues in the characteristics of dairy products and in their manufacturing process, on the development and spread of antibiotic-resistant bacteria, and on the effects that both residues and resistant bacteria can cause on human and environmental health.he research group was funded by The University of the Basque Country (UPV/EHU) (grant COLAB20/14) and by the Basque Government, grant to Research Groups number IT944-16. G. Santamarina-García received a predoctoral grant from the University of the Basque Country

Antimicrobial resistance in dairy slurry tanks: A critical point for measurement and control

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Antimicrobial Resistance: the use of antimicrobials in the Livestock Sector

The use of antimicrobials in livestock production provides a basis for improving animal health and productivity. This in turn contributes to food security, food safety, animal welfare, protection of livelihoods and animal resources. However, there is increasing concern about levels of antimicrobial resistance in bacteria isolated from human, animal, food and environmental samples and how this relates to use of antimicrobials in livestock production. The report examines antimicrobial usage in livestock and its impact on public health and the food economy. Policy issues and knowledge gaps to manage antimicrobial use and the risk of antimicrobial resistance are identified and discussed

A Narrative Review on the Unexplored Potential of Colostrum as a Preventative Treatment and Therapy for Diarrhea in Neonatal Dairy Calves

Diarrhea is the leading cause of morbidity and mortality in pre-weaned dairy calves and, as such, represents a significant animal health and welfare concern. Furthermore, digestive disease early in life is associated with several long-term consequences such as reduced growth rate and decreased milk yield during the first lactation, thus generating severe economic losses. The majority of diarrheic cases in young calves are treated with antimicrobials; however, it is necessary to develop alternative treatments, as excessive antimicrobial usage can lead to antimicrobial resistance and can negatively impact the gut microflora of a calf. Bovine colostrum is abundant in immune and bioactive factors that improve immune function and development. This rich and natural combination of immunoglobulins, natural antimicrobial factors, growth factors, anti-inflammatories and nutrients may be an attractive alternative to antimicrobials in the treatment of diarrhea in young dairy calves. There is evidence that supports the use of colostrum as an early treatment for diarrhea in young calves. Future research should investigate its therapeutic and economic effectiveness

Bacteriophage Therapy to Control Bovine Mastitis: A Review

Bovine mastitis is a polymicrobial disease characterised by inflammation of the udders of dairy and beef cattle. The infection has huge implications to health and welfare of animals, impacting milk and beef production and costing up to EUR 32 billion annually to the dairy industry, globally. Bacterial communities associated with the disease include representative species from Staphylococcus, Streptococcus, Enterococcus, Actinomyces, Aerococcus, Escherichia, Klebsiella and Proteus. Conventional treatment relies on antibiotics, but antimicrobial resistance, declining antibiotic innovations and biofilm production negatively impact therapeutic efficacy. Bacteriophages (phages) are viruses which effectively target and lyse bacteria with extreme specificity and can be a valuable supplement or replacement to antibiotics for bovine mastitis. In this review, we provide an overview of the etiology of bovine mastitis, the advantages of phage therapy over chemical antibiotics for the strains and research work conducted in the area in various model systems to support phage deployment in the dairy industry. We emphasise work on phage isolation procedures from samples obtained from mastitic and non-mastitic sources, characterisation and efficacy testing of single and multiple phages as standalone treatments or adjuncts to probiotics in various in vitro, ex vivo and in vivo bovine mastitis infection models. Furthermore, we highlight the areas where improvements can be made with focus on phage cocktail optimisation, formulation, and genetic engineering to improve delivery, stability, efficacy, and safety in cattle. Phage therapy is becoming more attractive in clinical medicine and agriculture and thus, could mitigate the impending catastrophe of antimicrobial resistance in the dairy sector

Occurrence of Antibiotic Resistance in Environmental and Amphibian E. coli Isolates Associated with Cattle and Aquatic Environments

The widespread use of antibiotics in human medicine and livestock production has been linked to an increase in resistant bacteria, which may carry transferable resistance factors, including integrons. Foodborne pathogens, such as Escherichia coli and salmonella, commonly reside in livestock, including cattle, and these pathogens may acquire resistance genes as a result of routine antibiotic use. As cattle are often located in close proximity to aquatic environments, they may disperse antibiotic resistant pathogens into such environments, which may lead to contamination of aquatic wildlife. We hypothesize that class 1 integrons and/or antibiotic resistant bacteria occur more frequently in environments with cattle exposure, and resistance and class 1 integrons disperse into aquatic environments and wildlife, which in turn provides a reservoir of antibiotic resistant bacteria for cattle within that environment. We investigated the prevalence of resistance genes and class 1 integrons in E. coli from selected amphibian species from ponds within and adjacent to cow-calf beef production systems. Escherichia coli were isolated from bullfrog (Rana catesbeiana) and green frog (Rana clamitans) tadpoles, green frog metamorphs, cow manure, and pond water samples within each livestock system in an attempt to determine if transfer of resistant bacteria occurs. Integron prevalence within E. coli was determined by multi-plex PCR. Antibiotic resistance to tetracyclines, florfenicol, and sulfisoxazole were determined using standard microdilution broth Minimum Inhibitory Concentration technique. A selected subset of bacteria was analyzed for resistance patterns using the National Antimicrobial Resistance Monitoring System (N.A.R.M.S.). Class 1 integrons were detected in 3% of isolates (n = 63) from pond water and in 1% of isolates (n = 123) from cow manure. Integrons were not detected in isolates (n = 1014) from tadpoles or metamorphs. Tadpole samples with isolates resistant to tetracycline, florfenicol and sulfisoxazole were more prevalent (P=0.0001, P = 0.006 and P=0.0156 respectively) from cattle-accessible ponds compared to cattle-excluded ponds. The percentage of pond water samples with tetracycline resistant E. coli isolates was also greater in cattle-accessible ponds (P = 0.0283) compared to isolates from cattle-excluded ponds. Antimicrobial resistance patterns were observed to differ between treatments. Information from this study will provide key information for the development of strategies to reduce the prevalence and risk of antibiotic resistant organisms