Research On HPI Main Structure Genes Of E.coli Derived From Yunnan Saba Pigs And Their Pathogenicity

In order to know the relationships between HPI main structure genes of YunnanSaba Pigs E.coli and its pathogenicity, according to include PCR amplification test、colonyspots in situ hybridization test、iron-uptake system、animal experiment and drug-resistanceexperiments，for studying the pathogenic relationship of e.coli.Firstly，according to thedetection for CVCC1565strains by PCR amplification testing,which get the positivecontrol,then based on44superiority serotype strains of e. coli,by PCR amplification andcolony spots in situ hybridization method to detect the HPI irp2、irp1、irp3、irp4and irp5gene,sequencing, blasted the sequence of genes and published on the sequences ofGENBANK which get the homology were above95%, in adddition,based on comparisonof the system the evolution of the evolutionary tree distance, it is concluded that theexperimental strains on genetics has the feature of EIEC、UPEC、Y pestis and EPEC,Theprediction results of protein show that concerned to the differences of HPI HMWP1protein bands is related of glycosylation sites, and phosphorylation sites involved inenergy-and bio-oxidizing bacteria, which made bacteria get iron to enhance virulence ofHPI;SDS-PAGE experiment (under the concentration of0.2mmol/L2-2,-bipyridine)under the condition of iron deficiency shows that10superiority serotype HPI strains of e.coli have HMWPs expression; On CAS solid medium which strains can produce saffronyellow halo; sensitive experiment of beta lactam antibiotic, it is concluded that is sensitiveto cefoperazone, cefazolin;Animal pathogenic test get the LD50as102.93μl, anatomical deadmice found obvious pathological changes that swelling of the liver gray, spleen enlargement, and a dark purple rim, duodenal edema etc. Pathological histologyobservation, lung capillary hyperemia, emphysema and wide alveolar septa, myocardialfiber rupture, disordered arrangement, liver cell swelling, degeneration, and hepatic sinusbleeding, duodenal epithelium cell degeneration necrosis, intestinal villus off.Above theseexperimental results，which analysis that exists a certain connection between Yunnan Sabaswine E. coli HPI major structural gene and its pathogenic relationship.