Lethal dose 50 test of Pasteurella multocida Type A in mice
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- October 22, 2021
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Rohaiza Yahaya. Lethal dose 50 test of Pasteurella multocida Type A in mice. 30th Veterinary Association of Malaysia (VAM) Congress. 19th-20th October, 2018. Hilton Hotel, Petaling Jaya, Malaysia.(Abstract of e-Poster Presentation).
Rohaiza Yahaya, Suriani Mohd Nor, Ho Hung wui, Lily Rozita Md Hakin,Abdul Sukor Shaharudin, Rohayu Mohd Nasir
Veterinary Research Institute, Department of Veterinary Services,59, Jalan Sultan Azlan Shah, 31400 Ipoh, Perak, Malaysia
Corresponding author: email@example.com.
Potency test is mandatory quality control (QC) test in the vaccine production and involves using an animal model. Easy-to-manage animal mice have been selected as an alternative animal for potency testing of VRI’s Duck Pasteurellosis vaccine. However, the infectivity dose of Pasteurella multocida type A vaccine seed 5009 strain (PMA5009) that produces lethal effects has yet to be determined in mice. Hence, this study was conducted to determine the lethal dose 50 (LD50) of PMA5009 vaccine seed in mice. The PMA5009 vaccine seed was cultured from a freeze-dried working seed and incubated at37°C overnight. 10-15 single colony were added in Haemorrhagic Septicaemia Broth (HSB) for furthertest. 52 two-month-old swiss albino mice were divided equally into 13 groups according to the dilutions series (neat to -12) and were inoculated subcutaneously with 0.5 ml of serial ten-fold dilutions of bacterial suspension. Mice were closely monitored for seven days. The dilutions were also subjected to total viable count for estimation of colony forming unit (cfu). The result indicates that a titration group of 10¯â¹ contributed 50% of the mice mortality and is applicable in the vaccine potency test for QC test in vaccine production. The LD50 of 5.0 x 10¯â¹ cfu/ml of PMA5009 strain was calculated using the Spearman×Kärber method. Unfortunately, the low titration of LD50 obtained could cause toxicity to the mice. Therefore, further experiment using a different animal model such as guinea pig can also be conducted in future.
Keywords: lethal dose 50, Pasteurella multocida, duck pasteurellosis