ANTIBIOTIC SUSCEPTIBILITY OF PIGS TO E. COLI F4+

Abstract

The prevalence and antibiotic sensitivity of E. coli., and haemolytic E. coli. F4+ and haemolytic E. coli. F4- (E/F4+, E/F4-, HE/F4+ and HE/F4-) was investigated in five hundred and thirty, randomly collected, rectal swabs from pig herds in five areas of Thailand, between the dates June 2000 and January 2001. The prevalence of E/F4+,
in each area was statistically significantly different with a range of 21.8-42.5% (30.4±8.8%). The greatest prevalence was found in the Northern area of Thailand, following by the Central, Western, Eastern, and Northeastern areas, respectively. The prevalence of E. coli. and haemolytic E. coli. F4+ and F4- was significantly different from each other, which was not the case for haemolytic E. coli. F4+ and F4-. The antibiotic susceptibility patterns of E/F4+ from each area were similar, being sensitive to Apramycin, Colistin, Gentamicin and Norfloxacin, intermediately sensitive to Ceftiofur, Enrofloxacin, and Cephalexin but resistant to Chloramphenicol, Kanamycin, Furazolidone, Sulfamethoxazole & trimethoprim and Neomycin. When a comparison was made between E. coli. F4+ and F4-, the antibiotic sensitivity patterns were similar. In addition, HE/F4+ strains were sensitive to Apramycin, Cephalexin, Colistin, Gentamicin, Neomycin and Norfloxacin while HE/F4- strains were sensitive to Cephalexin, Colistin and Gentamicin. However, some herds were found to be different from the majority, due to different antibiotic usage in each herd.