**5. Conclusions**

Current mastitis control programs are based on teat disinfection, antibiotic therapy, and culling of chronically infected cows. There is no single effective vaccine against any mastitis pathogen. The physiological nature of mammary glands where induced systemic immune responses need to cross from the body into the mammary glands, the dilution of effector immune responses by large volume of milk coupled with the ability of mastitis causing bacteria to develop immune evasion mechanisms and resistance to antimicrobials makes control of mastitis very difficult. However, developing improved and effective vaccines that overcomes these constraints using these quickly advancing molecular, genomic and immunological tools is a sustainable intervention approach.

Use of antibiotics in food-producing animals does contribute to increased antimicrobial resistance in dairy cattle and farm environments. Antimicrobial resistance among dairy pathogens, particularly those bacterial strains that cause mastitis in dairy cattle, is not increasing at alarming rate. However, antimicrobial resistance among Gram-negative bacteria particularly those strains that mainly cause disease in humans are extremely high in dairy cattle and dairy farm environments. Transmission of an antimicrobial resistant mastitis pathogen and/or foodborne pathogen to humans could occur through direct contact with animal or indirectly through the food chain, if contaminated unpasteurized milk or dairy products made from contaminated raw milk is consumed, which is another very important reason why people should not consume raw milk. Likewise, resistant bacteria contaminating meat from culled dairy cows can easily transmit to humans through consumption of undercooked meat.

We emphasize and recommend the prudent use of antibiotics in dairy farms. Strategies involving prudent use of antibiotics for treatment encompass identification of the pathogen causing the infection, determining the susceptibility/ resistance pattern of the pathogen to assess the most appropriate antibiotic to use for treatment, and a long enough treatment duration to ensure effective concentrations of the antibiotic to eliminate the pathogen. Alternatives to use of antibiotics for maintaining animal health and productivity based on preventative measures, such as vaccination, improved nutrition, environmental sanitation, use of teat sealants, and selection for disease resistance genetic traits together with advances in more rapid pathogen detection and characterization systems will undoubtedly play an integral role in strategies aimed at improving dairy productivity with improved safety of dairy products for human consumption.
