| Swine Streptococcosis is an important zoonosis,which has brought great harm to Pig Industry and human health as well as public health security in clinical practice.In order to ascertain the infection circumstances and incidence condition of Swine streptococcal diseases in some piggery in Korla city of Xinjiang,this study made investigation on pig farms where Swine Streptococcosis were suspected occurring in Korla city of Xinjiang,through field investigation,clinical observation,pathological anatomy and isolation and identification of pathogen,with the aimof providing technical support for prevention and control of Swine Streptococcosis and offering theoretical basis to formulate valid prevention and control measure.1.To make on-spot epidemiological investigation on part of piggery in Korla city of XinjiangSince 2014 to 2016,we have made investigation on the suspected Swine Streptococcosis in 7 pig farms,as for the pigs of 21-70 days age,the incidence rate of Swine Streptococcosis reaches 4.97%-5.3%,the adult pigs 18.8%-19.9%;the fatality rate for the pigs of 21-70 days age reaches 54.24%-56.24%,the adult pigs15.3%-19.7%.The sick pigs present depressed in spirit clinically,with the body temperature 41.5-42?,continuous fever,dullness,lethargy,loss of appetite,or not eating food,and fondness of drinking;Eye conjunctiva is flush,there is a speck,tears,and the serous or purulent nasal fluid,difficult to breathe,there are hemorrhagic erythema under the tip of ear,the lower four limbs and under abdomen,combined with arthritis,which are in conformity with the symptoms of infection of Swine Streptococcosis.The necropsy of the dead pigs demonstrates pathological changes characterized by exudative diathesis of the body and the congestion and enlargement of the viscera,in accordance with Swine Streptococcosis disease and primarily diagnosd as infected by Swine Streptococcosis.2.The isolation and identification of pathogen and serotyping for Swine streptococcal diseases in some piggery in Korla city of Xinjiang.The specimen of liver,spleen,lung,synovial fluid,skin abscess from 120 dead pigs of 7 pig farms in Korla city have been conducted smear dyeing for microscopic examination,isolation and culture,biochemical character and PCR identification,in result,10 strains of Streptococcosis are isolated and identified.The morphology,dyeing and culture characteristics are basically in line with the characteristics of Streptococcus,and the biochemical test results basically accorded with the biochemical characteristics of swine streptococcus.According to swine streptococcus 16 SrRNA ribosomal gene and gdh gene primers by using PCR methodfor identification of streptococcus species,and on this basis to isolate and identify the1,2,7,9 serotype of Streptococcus by using the PCR method.The results showed that16 SrRNA positive strain havespecificity bands at 328 bp,gdh positive strains have specificity bands at 688 bp,2 strains of type-1 streptococcus,2 strains of type-3Streptococcus,type-7 and type-9 were not detected,and other 5 strains of Streptococcus are unknown serotype.3.Drug susceptibility test for isolated strains of Swine streptococcosis in some piggery in Korla city of XinjiangDrug susceptibility tests were carried out on Streptococcosis which have been isolated and identified.The test results presented that the strains isolated have strong resistance to enrofloxacin,Benzylpenicillin potassium and Gentamicin with resistance rate of 80%,and resistance rate of 70% to Ampicillin,while they have high sensitivity to kanamycin,ciprofloxacin and florfenicol,especially they are sensitive to ciprofloxacin with sensitivity rate of 90%,as for azithromycin,oxytetracycline and sulfadiazine they showed moderate resistance.The results showed that surveyed isolated strains of Swine streptococcal are highly resistant to penicillin,ampicillin,enrofloxacin,gentamicin;so it needs our attention in choosing antibacterial drugs in prevention of swine streptococcus disease. |
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