Actavia 0 Nedbalcova, K. Satran, P. Jaglic, Z. Ondriasova, R. Kucerova, Z. 2005 2005-5-31 181-185 During the period of 2001 and 2003 a total of 238 isolates of Actinobacillus pleuropneumoniae obtained from 26 pig herds in the Czech Republic (2001 - 73 isolates, 2002 - 110 isolates, 2003 - 55 isolates) were examined for antibiotic resistance by disc diffusion method. Resistance to erythromycin (95.5% to 98.6%), streptomycin (76.4% to 82.7%) and tiamulin (72.7%) was detected most frequently over the whole monitored period. High increase in percentage of resistant isolates to tetracycline (2001 - 11.0%, 2002 - 36.4%, 2003 - 81.8%), doxycycline (2001 - 9.6%, 2002 - 34.6%, 2003 - 61.8%), nalidixic acid (2001 - 2.7%, 2002 - 14.5%, 2003 - 45.5%), and norfloxacin (2001 - 0%, 2002 - 7.3%, 2003 - 34.6%) was found, while differences in resistance to cephalotine (2001 - 1.4%, 2002 - 7.3%, 2003 - 9.1%), cotrimoxazol (2001 - 4.1%, 2002 - 10.0%, 2003 - 7.3%), amoxicillin (2001 - 12.3%, 2002 - 12.7%, 2003 - 10.9%) and amoxicillin-clavulanic acid (2001 - 9.6%, 2002 - 9.1%, 2003 - 10.9%) were small. Prevalence of isolates resistant to sulfasomidine was detected decreasing (2001 - 43.8%, 2002 - 47.3% and 2003 - 29.1%). 5 50