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Table 4 Protective efficacy of the S-8clpapxIIC mutant against A. pleuropneumoniae S-8 and K17 challenge in pigs

From: Attenuated Actinobacillus pleuropneumoniae double-deletion mutant S-8∆clpP/apxIIC confers protection against homologous or heterologous strain challenge

Group Immunogen Strain for challenge Temperature (°C) a Appetiteb Lethargyb Dyspneab Lung lesion scorec
1 S-8clpPapxIIC S-8 39.4 ± 0.2 0.2 ± 0.3* 0.2 ± 0.3** 0.1 ± 0.2** 1.4 ± 2.2*
2 PBS S-8 40.3 ± 0.5 2.4 ± 1.1 2.0 ± 0.6 2.3 ± 0.6 20.2 ± 11.9
3 S-8clpPapxIIC K17 39.6 ± 0.3 0.3 ± 0.4* 0.3 ± 0.4** 0.4 ± 0.4** 1.7 ± 2.5**
4 PBS K17 40.5 ± 0.4 2.6 ± 1.7 2.3 ± 0.5 2.6 ± 0.4 22.8 ± 9.3
  1. a The average temperature value for each piglet during the observation period after challenge was calculated and the mean temperature value for each group was determined
  2. b Clinical signs were scored as described by Jolie et al [24]. Appetite was scored as follows: 0, did eat; and 1, did not eat. The total score equaled the number of 12-h periods of not eating over the 36-h observation period. Lethargy was scored as follows: 0, normal; 1, slight inactivity; 2, moderate; and 3, severe. Dyspnea was scored as follows: 0, normal; 1, slight; 2, moderate; and 3, severe. The final scores were obtained from the average of all of the data within the observation time and are expressed as arithmetic means ± SD; *, significance at a P value of <0.05; **, significance at a P value of <0.01
  3. c The lung lesion score was determined as described by Hannan et al [25]