The immunoglobulin M-degrading enzyme of Streptococcus suis, Ide Ssuis , is involved in complement evasion

Table 1 Scoring of fibrinosuppurative lesions of growing piglets intranasally infected with the indicated S. suis strains after prime-vaccination with a S. suis serotype 2 bacterin

Infection strain ^a	Piglets without lesions	Piglets with lesions in three or more locations	Brain			Serosae			Joint			Spleen and liver			Lung			Heart
			Meningitis, chorioiditis			Pleuritis or peritonitis			Synovialitis			Splenitis ^b or hepatitis			Pneumonia			Endocarditis
			5 ^c	3 ^d	1 ^e	4 ^c	2 ^d	1 ^e	4 ^c	2 ^d	1 ^e	4 ^c	2 ^d	1 ^e	4 ^c	2 ^d	1 ^e	4 ^c	2 ^d	1 ^e	ω ^f
wt	1/9	5/9	1/9	0/9	0/9	4/9	0/9	0/9	2/9	0/9	0/9	3/9	3/9	0/9	6/9	0/9	0/9	0/9	0/9	0/9	3.7
Δ	3/8	3/8	3/8	0/8	0/8	0/8	1/8	0/8	1/8	2/8	0/8	1/8	1/8	3/8	1/8	2/8	0/8	0/8	0/8	0/8	2.2
Δ_h	2/8	4/8	2/8	0/8	0/8	3/8	0/8	0/8	0/8	0/8	0/8	0/8	4/8	2/8	3/8	1/8	0/8	2/8	0/8	0/8	2.9

^aInfection strains were strain 10 (wt), 10Δide _Ssuis (Δ) and 10Δide _Ssuis _homologue (Δ_h).
^bNeutrophilic accumulation of the splenic red pulp.
^cScoring of 4 and 5 indicates moderate to severe diffuse or multifocal fibrinosuppurative inflammations.
^dScoring of 2 and 3 indicates mild focal fibrinosuppurative inflammation.
^eIndividual single perivascular neutrophils received a score of 1.
^fω = Σscore_max/n_animals [15].

ISSN: 1297-9716