Phylogenetic And Resistance Analysis And Virulence Factors Of Escherichia Coli From The Uterine Of Postpartum Dairy Cows

Endometritis is the most common reproductive disease after parturition. The outcome disorders of the uterus and ovaries, calving interval prolongation and the conception rate can reduce milk yield, which seriously affected the economic efficiency of dairy production. Our study was conducted to determine the relationship among E. coli serotypes, resistance of E. coli, uterus mucus traits, E. coli phylogenetic group and virulence factors by culture and molecular biology techniques infecting endometritis after21-30days parturition.1The serotypes of E. coli isolated from uterus of parturitum dairy cowsUterine secretion was collected and rectal temperature were measured from60dairy cows from d21to d30after parturition. Bacteria was identified with aerobic culture in vitro. The results showed that43of60cows (71.7%) were isolated E. coli. The body temperature from both health and endometritis cows were38.7℃on the average. Sixty-one E. coli were isolated from18healthy dairy cows; Eighty-four E. coli were isolated from25endometritis cows. The results showed that the high ratio of separation of E. coli were isolated from the dairy cow uterus after21-30days parturition. Inflammatory uterine from the systemic inflammatory have changed to the partial inflammatory, and the body temperature recovered to normal. Ninety-six of145strains E. coli were serotyped belonging to15different serotypes, of which84(87.5%) belonging to the7serotypes were O2, O5, O26, O44, O73,086and O111. These were common serotypes. O2(3strain) and O86(4strains) appeared in the infected cows, O2and O86were may be pathogenic E. coli.2Phylogenetic grouping and resistance of E. coli isolated from uterus of dairy cowsThe145E. coli were collected from60dairy cows from d21to d30after parturition, E. coli phylogenetic groups were determined by PCR, and antibiotic resistance was determined by23types of antibiotic. E. coli belonging to phylogenetic group A (n=51,35.2%), B1(n=87,60.0%), D (n=7,4.8%), had no isolated B2E. coli. E. coli from group A had more group B1from endometritis cows (P<0.05); Healthy cows were isolated more E. coli of group D than endometritis, but it was not different (P=0.513); Group B1both in healthy and endometritis cows (P=0.801). The results showed that group A may have the pathogens E. coli that could cause bovine endometritis, E. coli from group B1may be the common of the host or potential pathogens of some situationgs, which may be the E. coli from group D that had no pathogenicity. Twenty-three types of antibiotic tests of the145E. coli showed that131E. coli (83.4%) had more than one antibiotic resistance. The strongest multi-drug resistant E. coli had16types of antibiotics resistance. The E. coli antibiotics resistance was stronger in endometritis than healthy cows. E. coli multidrug resistance was stronger from group A than B1.E. coli from group A, which may be more likely to cause recurrent endometritis.3E. coli fingerprinting and virulence factors of postpartum cows uterineCombined with the serotype and phylogenetic groups of E. coli,145E. coli from postpartum cows, was determined fingerprints by RAPD. E. coli phylogenetic was based on UPGMA algorithm.20virulence genes of E. coli were determined by PCR. The results showed that the cow delivery associated with intrauterine infection risk probability from high to low after giving birth to the first cattle> retained placenta> male calf stillbirth> twins. The RAPD results indicated that the145E. coli belonging to four clusters had lower similarity. The E. coli of the same cow was similar. Different E. coli phylogenetic groups showed different clusters. E. coli from group A may be potentially pathogenic; Group B1may appear purulent inflammation, relating with the serious endometritis; Group D had no obvious correlation with cows. In some certain clusters, O44E. coli was associated with serious purulent inflammation of endometritis. Serotypes of E. coli and phylogenetic group existed no differences. E. coli virulence gene by PCR showed that20virulence factors were detected out of10species. An E. coli strain has five kinds of virulence factors at least and has nine at most. FimH and OmpA were found that were risk of endometritis. FimH existed and contained another or more virulence factors leading to enhancement of E. coli pathogenic.In conclusion, we found no relationship between E. coli virulence factors and polymorphism analysis.