Isolation And Identification Of Arcanobacterium Pyogenes From Goat And It's Pathogenicity Experiment On Mice

Arcanobacterium pyogenes often cause cattle, sheep, pigs and other animals, purulent infection, mainly pneumonia, arthritis, endocarditis, mastitis, subcutaneous abscess and so on can cause great harm with livestock. Recent in pig, cattle, dogs and wild animals, Arcanobacterium pyogenes are isolated and reported in domestic and abroad. This study Isolated and identified Arcanobacterium pyogenes from goat and do pathogenicity experiment in mice.1,Isolation and Identification of Arcanobacterium pyogenes from goatSterile taken lungs from goat inoculated blood culture medium were cultured for anaerobic and aerobic culture, the culture temperature were 37℃. Anaerobic and aerobic culture after 48h culture, blood culture medium were grown 1-2mm, round, colorless, surface uplift, neat edge, dew-like colonies; strain withβ-hemolytic properties, as facultative anaerobic; this of the bacteria were Garm, methylene blue staining and capsule, spores, flagella staining. Gram-positive bacteria, no movement, no capsule, no small Bacillus subtilis, form heterogeneous, multi-alone or in pairs in particular showed a "V" shape, or there were bundles, methylene blue coloring bad; on isolates the best medium for screening, the result is bacteria in nutrient broth and nutrient agar growth poor, in serum broth, serum agar growing well, more rapid growth of anaerobic culture; bacteria can ferment glucose, lactose, fructose, maltose produced acid but no gas, can not ferment raffinose, sorbitol, mannitol, sucrose, arabinose, Euonymus alcohol and rhamnose. MR test, tested positive for gelatin liquefaction, indole test, hydrogen sulfide, VP test, nitrate reduction test, catalase test was negative, can peptone acid coagulation of milk, biochemical test results and the biochemical characteristics of bacteria Arcanobacterium pyogenes agreement; of the 16s rRNA sequence analysis of the bacteria, the results with the Genebank Arcanobacterium pyogenes 99% homology, the sequence has been included Genebank, accession number for the HM246725. The test successfully isolated Arcanobacterium pyogenes from goat, named SC-1.2,Pathogenicity experiment of Arcanobacterium pyogenes on mice Take amount of Arcanobacterium pyogenes from goat (about 7.9×108 cfu/0.3ml), equal amount of sterile saline washing three times, according to 0.3ml/10 mice by intraperitoneal injection only. Results dose of 7.9×108 cfu/0.3ml Arcanobacterium pyogenes causes all mice died within 72h, dead mice, liver, lung purulent swelling, spleen congestion, epicardial bleeding points, kidney and brain had no significant lesions and death of mice from the heart, liver, spleen, lung, kidney isolated the bacteria. Pathological results showed that the heart, liver, spleen, lung, kidney pathological changes of different degrees; take appropriate bacteria strain, repeated washing three times, resuspended appropriate sterile saline (about 7.9×108 cfu/0.3ml), Repeated freezing and thawing 3 times, sonication cell filtration sterilization, the filtrate by 0.5ml/only tail vein injection of 5 mice were continuously observed for 15d 5 mice were healthy living; the check amount of bacteria bacteria (about 7.9×108 cfu/0.3ml), filter sterilization, the filtrate by 0.5ml/only tail vein injection of 5 mice. Results filtrate in 48～72h in all the mice died; this Arcanobacterium pyogenes were hemolysin gene (PLO) of the PCR amplification. The PCR products PLO hemolysin gene, the size of 270bp; test results showed that the Arcanobacterium pyogenes SC-1 in mice with lethal and external toxins is the main pathogenic factor, endotoxin induced non-pathogenic or disease was not strong, with the PLO hemolysin gene. Selected 16 kinds of drugs to the strains of Arcanobacterium pyogenes susceptibility test. Bacteria to penicillin, cefotaxime, gentamicin, tetracycline, rifampin is highly sensitive to amikacin, neomycin, erythromycin and moderately sensitive to azithromycin resistance. The test of the Arcanobacterium pyogenes from goats the pathogenicity preliminary study, the follow-up depth for the diagnosis of this bacteria, and pathogenic mechanism of prevention and control research foundation.