STUDY ON DNA POLYMORPHISM OF ADHERENCE GENE CLUSTER OF UROPATHOGENIC E.COLI

Aim In order to study the DNA polymorphism of the adherence gene cluster among uropathogenic E coli (UPEC) strains Methods Based on the hemoagglutination test, the adherence gene cluster analyses were carried out by using DNA hybridization methods with the probes of the pap ACDH including the structural gene for the P-fimbriae subunit and the papEFG including the actual P-adhesin for 95 stains of E coli isolated from urine Results It was showed that MRHA ～,and negative strains were 37 9%,32 6% and 29 5%, respectively Using colony hybridization in situ and DNA dot blotting, the hybridized positive strains with above two probes among MRHA ～, and negative stains were 91 7%, 9 7% and 21 4%, respectively; the hybridized positive strains with one of both probes in MRHA  and negative examined strains were 64 5% and 35 7% Meanwhile, the chromosomal DNA was extracted from the 10 strains with MRHA  character and was digested with the restriction endonuclease EcoR Ⅰ Then the restriction fragment length polymorphism (RFLP) of UPEC were studied by Southern hybridization methods The homologous fragments of the tested strains with two probes were different in the size and the light and shade degree Conclusion It was inferred that pap adherence gene cluster of uropathogenic E coli strains may be very diversity