Isolation Of Pathogenic Bacteria Of Subclinical Mastitis And Research On Anti-inflammatory Mechanism Of Chlorogenic Acid

In order to study the kinds of pathogenic bacteria in Guiyang dairy farm which caused bovine subclinical mastitis and the anti-inflammatory mechanism of chlorogenic acid(CGA).CMT was used to detect subclinical mastitis.Pathogenic bacteria were isolated from sick cow’s milk.After purification and biochemical identification,we made mastitis model for studying anti-inflammatory mechanism of CGA.First,we did the tests, including acute toxicity,ear swelling,capillary permability and LPS induced pathological changes in mice to evaluate the protective effects of CGA for breast tissue.Then, we detected the expression of IL-6 and TNF-α by ELISA method,to preliminary discussion the anti-inflammatory mechanism of chlorogenic acid.The results showed that Gram-negative bacterias were accounted for 27.54%(46strains) and Gram-positive bacterias were 72.46%(121strains).By intraperitoneal injection of injecting 0.2mg·mL-1of CGA,CGA had significant inhibitory effects on auricle swelling and capillary permeability in mice(P<0.05,P<0.01).Under the stimulation of 25μL,0.2mg·mL-1 LPS, there were obvious inflammatory injury in observation of necropsy,pathology aspect and electronic microscopy sections of the breast tissue in pregnant female rats.Different concentration groups of CGA(25mg·kg-1,50mg·kg-1,75mg·kg-1)had dose-dependent relation,with the increase of dose,the ease of degree of hyperemia and swelling on mammary tissue,the wall of MECs became thiner,the number of neutrophil decreased,the degree of organelles damage tended to taperoff,compared with LPS group. LPS group was significantly different comparing with 50mg·kg-1,75mg·kg-1 CGA group(P<0.01).The content of IL-6 in LPS stimulation group was significantly differet comparing with CGA groups(P<0.01).The content of TNF-α in control group was significantly differet comparing with LPS stimulation group and 20μg·mL-1 and 200μg·mL-1 CGA groups(P<0.01).From the results above,we can conclude that Gram-positive bacteria play animportant role in the kinds of bacteria which caused bovine subclinical mastitis,so we have a clear direction for treatment.In general,CGA has a good anti-inflammatory activity.By the studying of above,we can provide theory basis for prevention and control of bovine subclinical mastitis,and CGA also have greatly potential.