Bovine Respiratory Disease Pathogens Research Articles

Minimum Inhibitory Concentration Determinations for Ceftiofur and Spectinomycin against Pasteurella multocida, Mannheimia spp. and Haemophilus somnus from France, The Netherlands, and Germany

Ceftiofur is an extended-spectrum cephalosporin approved in many countries worldwide for treatment of bovine respiratory disease (BRD), as well as respiratory disease of other animals. Ceftiofur has demonstrated excellent in vitro activity against bacteria of importance in BRD: Mannheimia spp., Pasteurella multocida, andHaemophilus somnus. Spectinomycin is an aminocyclitol antimicrobial agent. Spectinomycin sulfate was recently approved in the United States for treatment of BRD caused by P. multocida, Mannheimia spp., and H. somnus; approvals are currently pending in other countries. To determine the in vitro activity of ceftiofur and spectinomycin against recent BRD pathogens from France, The Netherlands and Germany, minimum inhibitory concentrations (MIC) were determined.

A 4-year survey of antimicrobial susceptibility trends for isolates from cattle with bovine respiratory disease in North America

The antimicrobial susceptibility trends of bovine respiratory disease (BRD) pathogens isolated from 1988 to 1992 were determined. A total of 880 isolates representing Pasteurella haemolytica, Pasteurella multocida, and Haemophilus somnus were used in the study. Overall, resistance to ampicillin, tetracycline, erythromycin, and sulfamethazine was frequently encountered among strains of P. haemolytica and P. multocida. Ceftiofur, an extended-spectrum cephalosporin originally marketed in 1988 for the treatment of BRD, was very active against the BRD pathogens tested; the MIC of ceftiofur for 90% of isolates tested was < or = 0.06 microgram/ml. Resistance to spectinomycin varied on the basis of the breakpoint used. Substantial variation in the year-to-year susceptibility of BRD pathogens to tilmicosin, a new macrolide antimicrobial agent, was observed. The proportion of susceptible P. haemolytica isolates ranged from 84.7% in the second year to 7.1% in the third year and 78.2% in the fourth year. Similar fluctuations were observed with strains of P. multocida.