Comparison of resistance and virulence patterns of Escherichia colistrains isolated from vaginal secretion of normal and infected sows

摘要

During the last few years, there has been an increase in the number of reports of piggeries with low fertility associated to vaginal secretion, which can have urinary or genital origin. Discharges of genital origin can occur in the periods after farrowing or after breeding. The most frequently isolated bacterium is Escherichia colt, possibly due to ascendant infections. It was recently suggested that the pathogenicity of E. coli strains, isolated from sows with genital infections, has many factors.However, there is still little information on virulence factors present in strains isolated from the genital tract of normal and infected pigs. In E. coli samples isolated from the intestinal tract of humans and animals, the presence of fimbriae is an important factor of pathogenicity, as it provides the bacteria the ability to adhere to the mucosa. There are evidences that the ability to adhere also participates in extra-intestinal infections caused by E. coli. The production of hemolysin has been related to the ability of E. coli strains to cause cellular lesions, and has been used as a virulence marker. ViruIent strains of several pathogenic bacteria are also more hydrophobic than non-virulent strains. The Congo Red test is used to indicate hydrophobicity and is related to the pathogenicity of bacteria. This study aimed to compare the presence of some virulence factors in samples of E. coli isolated from the cervix secretion of sows with clinical signs of vulvar secretion to normal sows. The levelof resistance of the isolated samples to some antibiotics was also studied.