Pathogenic variability among Pasteurella multocida type A isolates from Brazilian pig farms

BMC Veterinary Research

Table 4 Clinical signs (%) and pathological lesions (%) in pigs challenged with Pasteurella multocida type A

Variables	Groups†									p*
Variables	G0	G1	G2	G3	G4	G5	G6	G7	G8	p*
Clinical signs
Hyperthermia	0.00^b	100.0^a	62.50^ab	100.0^a	75.00^ab	75.00^ab	12.50^b	100.0^a	25.00^b	< 0.0001
Dyspnea	0.00^c	100.0^a	37.50^b	87.50^ab	0.00^bc	25.00^bc	0.00^bc	100.0^a	0.00^bc	< 0.0001
Cough	16.67^b	50.00^ab	37.50^ab	12.50^b	0.00^b	37.50^ab	0.00^b	87.50^a	0.00^b	0.0002
Macroscopic lesions
Cranioventral lung consolidation**	0.00^c	62.50^ab	37,5,00^ab	87.50^a	12.50^b	0.00^bc	0.00^bc	75.00^a	0.00^bc	< 0.0001
Cranioventral lung consolidation (%)***	0.00 ± 0.00^b	3.58 ± 1.51^ab	2.53 ± 1.43^ab	6.26 ± 2.38^a	1.30 ± 1.30^b	0.00 ± 0.00^b	0.00 ± 0.00^b	5.01 ± 1.58^a	0.000 ± 0.00^b	0.0004
Necrotic nodules	0.00^c	62.50^a	37.50^ab	75.00^a	0.00^bc	0.00^bc	0.00^bc	37.50^ab	0.00^bc	< 0.0001
Diffuse fibrinous pleuritis	0.00^c	50.00^ab	0.00^bc	75.00^a	0.00^bc	25.00^abc	0.00^bc	50.00^ab	0.00^bc	< 0.0001
Mild focal fibrinous pleuritis	0.00	0.00	0.00	0.00	0.00	12.50	0.00	12.50	0.00	0.7074
Diffuse fibrinous pericarditis	0.00^c	25.00^abc	25.00^abc	62.50^a	0.00b^c	25.00^abc	0.00^bc	37.50^ab	0.00^bc	0.0029
Fibrinous peritonitis	0.00^d	62.50^a	12.50^bcd	37.50^ab	25.00^abc	50.00^ab	0.00^cd	50.00^ab	0.00^cd	< 0.0001
Microscopic lesions
Fibrinonecrotic suppurative/fibrinonecro-haemorrhagic pleuropneumonia	0.00^c	87.50^a	50.00^ab	87.50^a	0.00^bc	0.00^bc	0.00^bc	75.00^a	0.00^bc	< 0.0001
Fibrinopurulent pleuropneumonia	0.00	0.00	0.00	0.00	12.50	0.00	0.00	12.50	0.00	0.7074
Suppurative lymphadenitis	0.00^c	12.50^bc	37.50^ab	75.00^a	12.50^bc	12.50^bc	0.00b^c	37.50^ab	0.00^bc	0.0005

Fever: Rectal temperature ≥ 40.0 °C
*Descriptive level of probability by Fisher’s exact test; percentages followed by different letters on the same line differ significantly by Fisher’s exact test (p ≤ 0.05)
**Suppurative bronchopneumonia in the histopathology assay
***Lung consolidation was measured based on the total percentage of the affected pulmonary area. Descriptive level of Kruskal-Wallis probability; averages followed by different letters differ significantly by the Wilcoxon test (p ≤ 0:05)
†G0 with 12 pigs and G1-G8 with eight pigs per group

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