Inactivated Vaccine Trial of &i&Mycoplasma gallisepticum&/i& in Ethiopia

摘要

The study and entire laboratory works were conducted from December 2014 to April 2015 in National Veterinary Institute, Bishoftu, Ethiopia. Formaldehyde inactivated Montanide ISA70 based Mycoplasma gallisepticum (MG) trial vaccine strain was confirmed the identity with known primer using PCR from locally isolates of National Veterinary Institute of Ethiopia. This study was aimed to develop formaldehyde inactivated Montanide ISA70 based MG vaccine in Ethiopia. It can help to device strategies in controlling the disease mainly through developing more effective vaccine which will replace the currently being imported vaccines by some farms. After culturing procedure, oil based inactivated MG trial vaccine was produced in suitable clean and secure accommodation. In this study, among different isolates, local isolate of Samuel farm in NVI was prepared and evaluated in chickens. The amount of immune antigen per 0.5 ml of the dose was 10~(7) Colony forming units (CFU) of the bacteria. The trail vaccine was prepared and evaluated at the age of 16 weeks of chickens; the chickens were randomly divided into three groups (A, B and C), each having twenty birds (10 male and 10 female). Each of group B was vaccinated group of imported-live vaccine with 30 μl intraocularly for comparing with inactivated trial vaccine, each bird of group C was inoculated with 0.5 ml indigenous or trial vaccine subcutaneously at mid neck region and group A was used as a control then challenge tests were performed. After challenge test, among non-vaccinated chickens (control or group A) 2 chickens were died (10%), thicken and cloudy appearance of the air sac showed 18 (90%), 2 chickens were not showed thickened and cloudy air sack (10%). Although among vaccinated group (inactivated vaccine or group C), all chickens did not show clinical signs or post mortem changes (100%). From attenuated imported live vaccine (group B), no clinical signs or post mortem changes were observed (100%). It was concluded that oil based MG vaccine induces protective level of anti MG antibodies in chickens.