Goat's Bacteriological Investigation Of Subcutaneous Abscess In Sichuan Areas

Goat's breeding has a long history, and has very high economic value. Since China's reform and opening up 30 years, the animal husbandry industry of goats develops rapidly, it has accounted for about 6% of the total output value of national animal husbandry industry. As a goat's raising big province, the total amount of goats in Sichuan province occupied the fifth of goats industry in our country. In the process of livestock production, subcutaneous abscesses of goat causes a huge economic losses to the sheep breeding industry as a common frequently-occurring disease. Untill now, there were many cases reported about this disease, but there was no effective treatment because of the diversity of the source of pathogenic bacteria. For this, our experiment surveyed the epidemiology of goat's subcutaneous abscess, collected samples of the cases,seprated and identified the pathogens from the samples.The results could provide effective scientific data for the prevention and treatment of the disease.From April to September in 2015, By investigating the prevalence of the disease in Xuanhan, Guang'an, Panzhihua, Bazhong and Ziyang, totally collected 47 samples of subcutaneous abscesses. Pathogenic bacteria were cultured from the samples of goats by anaerobic and aerobic conditions. Based on the colonal morphology and biochemical characteristics of bacteria, and 16S rRNA gene sequence analysis, pathogenic bacteria were isolated and identified. And two pathogenic bacterial strains were selected to determine the half lethal dose (LD50). Finally, drug sensitivity test of the pathogenic strains was carried out by means of Kirby-Bauer recommended by CLSI.1. Six goat farms has a total amount of 2440 goats, including 230 sick goats. The incidence ratio of the disease is from 8.36% to 11.27%, and the average incidence rate was 9.43%.47 subcutaneous abscesses samples were collected from goat farms for bacterial isolation and identification. Totally 118 bacteria including 42 gram negative bacteria and 76 gram positive bacteria were isolated and idetified. Gram negative bacteria included 15 isolates of E.coli.(accounting for 12.7%) and 27 isolates of Pseudomonas (accounting for 22.9%); gram positive bacteria included 22 isolates of Corynebaeterium pseuotuberculosis(accounting for 18.6%),13 isolates of Staphylococcus aureus(accounting for 11.0%) and 41 isolates of Bacillus(accounting for 34.7%).2. Isolation of the pathogenic bacteria strains are mainly Corynebacterium pseudotuberculosis strains and Staphylococcus aureus strains. Among them, the strain of Corynebacterium pseudotuberculosis on the pathogenicity of mice is stronger than Staphylococcus aureus strain, and LD50 were 107.5 cfu/ml and 109.7 cfu/ml, respectively.3. Drug sensitivity of 22 Corynebaeterium pseuotuberculosis strains and 13 Staphylococcus aureus to 9 commonly used antimicrobial agents were tested. The results showed that the tested strains appeared serious multidrug resistant. Drug sensitivity test showed that these two kinds of pathogens were different. Corynebacterium pseudotuberculosis strains are highly sensitive to Sulfamethoxazole, Streptomycin, Ciprofloxacin and levofloxacin,and highly resistant to Penicillin and Gentamicin. Staphylococcus aureus strains are sensitive to ampicillin, levofloxacin and rifampicin, and highly resistant to Penicillin, Ampicillin, Clindamycin and Ceftazidime.The study preliminarily suggested that both of Corynebaeterium pseuotuberculosis and staphylococcus aureus were the main pathogens in Sichuan goat subcutaneous abscess disease. The results could provide scientific reference for the research and development of the drug for the prevention and treatment of the disease.