Figure 1.

Modeling viral-bacterial co-infection in zebrafish. Scheme of the experimental set up of viral bacterial co-infection using zebrafish. A 72 hpf zebrafish larva is shown. Microbes are injected in the bloodstream [intravenously (iv)] via the dorsal aorta (red line) or the ventral vein (blue line). Subcutaneous injections of the bacteria (sc) are performed over a somite, in the caudal region of the larva. Sindbis virus (SINV) and Shigella flexneri bacteria (Shigella) are sequentially injected in the bloodstream (iv) of zebrafish larvae at 72 and 96 hpf. Both SINV + Shigella and Shigella + SINV sequential co-infections are tested. Non-injected fish and fish injected with SINV or Shigella alone are used as a control. Single SINV or Shigella injections are performed at 72 or 96 hpf depending on the sequential co-infection tested. Survival, viral replication, bacterial burden, neutrophil behavior and expression of antiviral and antibacterial related genes are monitored over time as represented (dotted black line).