Table 2 Summary of the experimental conditions of S. suis co-infection with viral pathogens using in vivo models
From: Review of the speculative role of co-infections in Streptococcus suis-associated diseases in pigs
S. suis co-infection parhogen | Age of pigs at the infection Virus / Bacteria | Route of infection Virus / Bacteria | Virus strain and dose | S. suis strain and dose | Main observed effects of co-infection | Ref | ||
|---|---|---|---|---|---|---|---|---|
PRRSV | 19 days | 26 days | IN | IN | 2 × 104.99 TCID50, high virulent PRRSV strain, genotype 2 2 × 104.47 TCID50, low virulent PRRSV vaccine strain RespPRRS/Repro™ | 2 × 108.3 CFU; serotype 2 (no further details on the strain) | ↑ Severity of clinical signs, mortality, and interstitial pneumonia lesions (especially those infected with the high virulent PRRSV strain) | [61] |
|  | 98 days of sow gestation | 5 days | IN | IN | 103.5 TCID50, PRRSV, genotype 2 | 8 × 107 CFU, serotype 2 (no further details on the strain) | ↑ Susceptibility of piglets to bacterial infection | [52] |
|  | 21 days | 28 days | IN/IM | IN/IM | 2 × 104.97 TCID50 PRRSV, genotype 2 | 109 CFU; serotype 7 (no further details on the strain) | ↑ Clinical signs and mortality | [65] |
|  | 49 days | 42 days* | IN | IN | 2 × 104 TCID50 Asian HP-PRRSV strains; US PRRSV strains, genotype 2 | 106 CFU; serotype 2 (no further details on the strain) | ↑ Clinical severity related to PRRSV virulence; ↓ levels of proinflammatory cytokines | [64] |
|  | 28 days | 21 days* | IN | IM | 106 TCID50 PRRSV MLV-like strain | 2 × 108 CFU; serotype 2 low virulence strain (no further details on the strain) | ↑ Clinical signs and mortality | [67] |
SIV | 35 days | 38 days | IN | IN | 2 × 107 egg infectious dose50/mL, H1N1 strain | 2 × 106 CFU; serotype 2; ST7 | ↑ Clinical signs, pathological changes, and cell apoptosis; ↑ gene expression for pro-inflammatory mediators | [76] |
PCV-2 | 28 days | 33 days | IN/IM 2 mL/3 mL | IN/IM 2 mL/3 mL | 2 × 106.5 TCID50 | 4.5 × 109 CFU; serotype 2; ST7 | ↑ Clinical signs; ↑ gene expression for pro-inflammatory mediators; ↓ gene expression for CD4, CD8, and MHC-II | [21] |
PRV | 63 days | 63 days | IN | IN | 5 × 103 TCID50 high or low virulent PRV strains | 109 CFU S. suis serotype 2 (no further details on the strain) | ↑ Clinical signs | [107] |