Identification On Etiology And Drug Resistance Of Henna Chicken Diarrhea Streptococcus

In aquaculture production. chicken has been plagued by diarrhea causing serious losses to the development of poultry industry. Diarrhea is just a clinical manifestation of digestive system caused by many reasons, diarrheal diseases can be divided into two major categories:infectious and non-communicable, according to the causes. many pathogenic microorganisms, the chicken Streptococcus is important one of pathogenic microorganisms causing chicken diarrhea. Chicken Streptococcosis is characterized by diarrhea. It can effect both young and adult chickens and show endemic. Streptococcus is widespread in nature and chicken farm and is also an integral part of the chicken intestinal flora.Flocks are prone to streptococcosis due to other diseases or stress factors. There is still no effective vaccine to prevent the disease. It is one of the major diseases threatening poultry industry. It is not difficult to treat streptococcosis if it is correctly diagnosed. But it must be noted that chicken streptococcus has showed drug resistance for antibiotic abuse. It is necessary to select suitable drug with drug sensitivity assay before to treat the disease.The study was carried out to determine serotypes of chicken streptococcus various regions of Henan province. At the same time, drug sensitivity assay was done to determine suitable drugs for chicken streptococcosis in Henan province, and it is also benefical to guide clinical medicine.Firstly, chicken streptococcosis was surveyed in several regions of Henan province. Pathological materials collected were sent to laboratory of microbiology and Immunology in Henan Agricultural University. Bacteria was separated and identified through agar culture, biochemical test. Pathogenicity of the isolated bacteria was evaluated through animal inoculation test. Finally, sensitive drugs to the bacteria were determined through drug sensitivity test.Survey results showed streptococcosis occurred in 19 chicken farms in 10 of 12 surveyed regions. Both layer and chickens could be infected at 10 up to 150 days old.32 strains of typical Streptococcus were isolated from the material collected. They were identified belonging to D streptococci poultry serogroup accounting for 68.75%(22/32). D fecal streptococci serogroup accounting for 28.12%(9/32). and D serogroup fecal Streptococcus accounting for 3.12%(1/32) respectively through biochemical test.Animal pathogenicity test was carried for every streptococcus strains isolated. They showed various degrees of symptom. lesion and mortality rate in chickens.13 kinds of antibiotics were used in the drug sensitivity test. Results showed that the majority of streptococcus strains were sensitive to penicillin, amoxicillin and cefazolin. but resistant to gentamicin. roxithromycin and norfloxacin. This was not consistent with the report by Zizhen Wang. All the results indicated that drug resistance of Streptococcus strains in Henan province have changed in certain degree.