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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]