Isolation And Identification Of Mycoplasma Felis And Study On The Curative Effect Of Huangqin Jinxia Prescription On Mycoplasma Pneumonia Model

Mycoplasmafelis pneumonia is a highly contagious respiratory disease in cats caused by Mycoplasma felis.The clinical symptoms of cats are mainly manifested as wet cough,sneezing,purulent nasal discharge,and other respiratory symptoms.Some can also infect the eyes,resulting in serous and purulent secretions.Mycoplasmafelis is prone to develop drug resistance and is very difficult to isolate and cultivate,which has become one of the challenges faced by clinical veterinary physicians.This study isolated Mycoplasma felis and infected New Zealand rabbits with Mycoplasma felis through nasal drops of concentrated bacterial solution,exhibiting clinical symptoms such as wet cough,sneezing,and purulent nasal fluid,laying the foundation for further research on Mycoplasma felis.After that,New Zealand rabbits were treated with "Huangqin Jinxia Prescription" and compared from imaging,pathological anatomy,pathological sections,inflammatory factors,oxidative stress indicators,pyroptosis factors and other aspects to explore the efficacy of traditional Chinese medicine prescriptions on mycoplasma pneumonia and provide new ideas for solving the problem of drug resistance of Mycoplasmafelis.The main research content includes:(1)Isolation and identification of MycoplasmafelisFour strains of mycoplasma were isolated from 80 cat nasal swabs collected from Shuangliu District,Qingyang District,and Wenjiang District in Chengdu,all of which exhibited typical "fried egg like" colonies under low magnification.After 16 s r DNA gene sequence alignment,all 4 strains were Mycoplasmafelis.A phylogenetic tree based on 16 s r DNA gene was constructed using MEGA-X 8.0,and the results showed that the isolate(0519)had the closest genetic relationship to the international standard strain ATCC23391.Selecting 0519 for drug sensitivity experiments,the results showed that in terms of traditional Chinese medicine,self-made traditional Chinese medicine drug sensitivity paper sheets with different concentrations have a certain inhibitory ability on 0519;In terms of western medicine,0519 was completely resistant to erythromycin and sensitive to doxycycline,tylosin,enrofloxacin and azithromycin.(2)Construction of a New Zealand Rabbit Mycoplasma Pneumonia ModelTo address the ethical issues that may arise from conducting experiments on cats,a model of mycoplasma pneumoniae infection in New Zealand rabbits was explored and established.The results showed that after 3 days of 108 CCU bacterial solution nasal drip,New Zealand rabbits could experience clinical symptoms such as decreased appetite,wet cough,and purulent nasal fluid;Digital X-ray imaging(DR)shows pathological images such as sarcoidosis,fibrosis,and bronchopneumonia in the lungs;On autopsy,pulmonary sarcoidosis,emphysema,congestion of the trachea,and phlegm were observed;Pathological sections showed changes in alveolar structure and extensive lymphocyte infiltration.(3)A Study on the Curative Effect of Huangqin Jinxia Prescription on Mycoplasma Pneumonia in New Zealand RabbitsIn order to explore the curative effect of Huangqin Jinxia Prescription on mycoplasma pneumonia in New Zealand rabbits,this experiment has set up a high-dose prevention group,high\medium\low-dose groups of Huangqin Jinxia Prescription,a doxycycline positive control group,a blank negative control group,and a model group.After 7 days of treatment,serum inflammatory factor C-reactive protein(CRP),interleukin-6(IL-6),and tumor necrosis factor-α(TNF-α)were measured through clinical symptoms,DR imaging,lung dissection,pathological sections,and ELISA methods;Oxidative stress indicators:superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),malondialdehyde(MDA),and pyroptosis factor cysteine aspartate specific proteinase-1(Caspase-1),antiskin D(GSDMD),interleukin-18(IL-18),interleukin-1β(IL-1β)Compare the therapeutic effects.The results showed that different medication regimens can effectively alleviate clinical symptoms and alleviate pulmonary pathological changes in New Zealand rabbits.ELISA results showed that compared with the blank group,inflammatory factors,pyroptosis factor and MDA in the model group were significantly increased(p<0.01),while SOD and GSH-Px were significantly reduced(p<0.01);Compared with the model group,the levels of inflammatory factors,pyroptosis factors and MDA in each administration scheme group decreased to varying degrees,and SOD,GSH-Px increased to varying degrees with similar trends,all of which were the most obvious changes in the prevention group,followed by the high-dose group.To sum up,Huangqin Jinxia Prescription can effectively alleviate the development of mycoplasma pneumonia in New Zealand rabbits,reduce the damage to tissues caused by inflammatory reaction and oxidative stress,and alleviate pyroptosis.The prevention group has the best therapeutic effect,and the therapeutic effect is positively correlated with the dosage.