Teat skin normal flora and colonization with mastitis pathogen inhibitors

Area of Science:

• Veterinary Microbiology
• Bacterial Pathogenesis
• Animal Health

Background:

• Mastitis remains a significant concern in dairy cattle, impacting animal welfare and economic viability.
• The teat canal is a primary site for mastitis-causing pathogen entry.
• Developing effective strategies for preventing pathogen colonization at the teat surface is crucial.

Purpose of the Study:

• To evaluate the potential of commensal bacteria, specifically Staphylococcus hominis 1, for colonizing teat surfaces.
• To assess the in vivo efficacy of S. hominis 1 in inhibiting mastitis pathogens.
• To determine the persistence of S. hominis 1 on the teats of dry cows and neonatal calves.

Main Methods:

• Isolation and characterization of normal teat flora.
• In vitro screening of isolates for inhibition of mastitis pathogens.
• Experimental inoculation of dry cow and neonatal calf teats with S. hominis 1.
• Sequential sampling to monitor the persistence and recovery of inoculated bacteria.

Main Results:

• Three of four tested normal flora isolates (Corynebacterium xerosis, Bacillus sp., Aerococcus viridans) showed limited persistence (<10 days) on dry cow teats.
• Staphylococcus hominis 1, an inhibitor of Gram-positive mastitis pathogens, demonstrated prolonged colonization.
• S. hominis 1 persisted for an average of 51 days or longer in neonatal calves and up to 28 days on dry cow teats.

Conclusions:

• Staphylococcus hominis 1 exhibits promising potential for colonizing teat surfaces and inhibiting mastitis pathogens.
• Colonization with S. hominis 1 in neonatal calves and dry cows warrants further investigation as a mastitis prevention strategy.
• Targeted application of S. hominis 1 could serve as an adjunct to existing mastitis control measures, particularly during the critical dry period.