Table 3 Summary of the experimental conditions of S. suis co-infection with bacterial pathogens using in vitro models
From: Review of the speculative role of co-infections in Streptococcus suis-associated diseases in pigs
Pathogen studied | Type of cells or growth medium | Co-infection bacterial strain(s) | S. suis serotype 2 strain | Co-infection dose | Goal of the study | Conclusions | Refs. |
|---|---|---|---|---|---|---|---|
Glaesserella parasuis | Neonatal tracheal porcine cell line (NTPr) cells | G. parasuis serotype 6 (low virulence) and serotype 5 (high virulence) | ST1 (high virulence) and ST25 (intermediate virulence) | Adhesion/invasion assays: 5 MOI (both bacterial species) Gene expression: 10 MOI (both bacterial species) | Adhesion and invasion; expression of inflammatory genes (qRT-PCR) | No effect | [54] |
| Â | Pulmonary alveolar macrophages | G. parasuis serotype 6 (low virulence) and serotype 5 (high virulence) | ST1 (high virulence) and ST25 (intermediate virulence) | Adhesion/invasion assays: 5 MOI (both bacterial species) Gene expression: 10 MOI (both bacterial species) *Phagocytosis: 100 MOI (both bacterial species) Expression of surface markers: 500 MOI/ 50 MOI for G. parasuis/S. suis | Adhesion/invasion, phagocytosis, inflammatory gene expression, and expression of surface markers | No effect | [54] |
Actinobacillus pleuropneumoniae (App) | Medium for bacterial culture (no cells) | App (no further details on the strain) | No details | App and S. suis mixed in 1:1 ratio | Biofilm formation, antibiotic resistance, and expression of genes for virulent factors | ↑ Biofilm formation (App), antibiotic resistance and genes coding for different (putative) virulence factors for both pathogens | [136] |
Bordetella bronchiseptica | Porcine precision-cut lung slice | Field strain of B. bronchiseptica | ST1 (high virulence) | 104 and 104 CFU/well for B. bronchiseptica and S. suis, respectively | Effect of a pre-infection with B. bronchiseptica on adhesion, colonization and toxicity of S. suis | ↑ Bacterial adherence, colonization and cell toxicity | [137] |