Resistance to selected beta-lactam antibiotics

Area of Science:

• Veterinary Microbiology
• Antimicrobial Resistance
• Animal Health

Background:

• Antimicrobial susceptibility and resistance are critical concerns in livestock health.
• Monitoring resistance trends in key bacterial pathogens is essential for effective treatment strategies.
• The Czech Republic has observed specific patterns in antimicrobial use and resistance in cattle and swine.

Purpose of the Study:

• To determine in vitro antimicrobial susceptibility and resistance trends.
• To analyze antimicrobial sales data in relation to resistance patterns.
• To assess pathogens like Actinobacillus pleuropneumoniae, Pasteurella multocida, Mannheimia haemolytica, and Escherichia coli.

Main Methods:

• A micro-dilution method was used for antimicrobial susceptibility testing.
• Isolates were collected from clinical cases of cattle and swine diseases (2007-2011).
• Antimicrobial sales data (population correction unit) were analyzed.

Main Results:

• High susceptibility to antimicrobials was observed in most respiratory pathogens.
• Mannheimia haemolytica showed moderate resistance to ampicillin.
• Escherichia coli exhibited low susceptibility to ampicillin and amoxicillin/clavulanic acid, with increasing resistance trends.

Conclusions:

• While respiratory pathogens generally remain susceptible, E. coli resistance is a growing concern.
• Increased sales of certain beta-lactams (ceftiofur, cefquinome) in pigs and cattle correlate with resistance trends.
• Judicious antimicrobial use is crucial to mitigate further resistance development.