Seven years survey of susceptibility to marbofloxacin of bovine pathogenic strains from eight European countries

Abstract

This study was conducted from 1994 to 2001 to determine the susceptibility of bovine pathogenic bacteria to marbofloxacin (a third generation fluoroquinolone used only in individual administration for animals). Strains originated in bovine diseases from eight European countries. They were isolated from gut infections ( Escherichia coli, salmonellae), mastitis ( E. coli, Staphylococcus aureus, Streptococcus uberis, S. agalactiae, S. dysgalactiae) and respiratory diseases ( Mannheimia haemolytica, Pasteurella multocida, Haemophilus somnus). There was no change in the MIC distributions for each species after the launch of marbofloxacin in 1997. In E. coli, a resistant population was present before the use of marbofloxacin having been induced by co- or cross-resistance to other antibiotics used previously. Over this period the only a significant change seen was an increase in MIC 90 of E. coli from the gut (1.275 μg/ml in 1994/1995 to 5.098 μg/ml in 2001). All the salmonellae were susceptible to marbofloxacin with a MIC 90 = 0.073 μg/ml in 2001 without development of high level resistance. The use of marbofloxacin seems not to have favoured a significant increase and spreading of resistant bacteria.