Environmental Gram-Positive Mastitis Treatment: In Vitro Sensitivity and Bacteriologic Cure

¹ Department of Clinical Sciences and CSU Diagnostic Laboratory, Colorado State Univeristy, Fort Collins 80525
² Pharmacia and Upjohn Animal Health, Kalamazoo 49001

A clinical trial was conducted in a large dairy herd to determine the efficacy of intramammary pirlimycin hydrochloride administration during lactation for bacteriologic clearance of gram-positive environmental clinical and subclinical mastitis infections. Quarters infected with environmental streptococci that received pirlimycin therapy (13/28) were 1.8 times more likely to resolve infection than untreated quarters (5/14). The small numbers of quarters infected with coagulase-negative staphylococci resulted in inadequate power to assess treatment differences in cure rate. Although the association was not statistically significant, quarters from cows with sensitive environmental streptococci isolates from composite samples (8/13) resolved infection with treatment at approximately twice the rate of treated quarters with resistant isolates (3/10).

Key Words: dairy cows • mastitis • treatment • sensitivity

Submitted on October 18, 1999
Accepted on April 23, 2001

This article has been cited by other articles:

				S. Marques, E. Silva, J. Carvalheira, and G. Thompson Short communication: In vitro antimicrobial susceptibility of Prototheca wickerhamii and Prototheca zopfii isolated from bovine mastitis. J Dairy Sci, November 1, 2006; 89(11): 4202 - 4204. [Abstract] [Full Text] [PDF]