Fig. 6: PICMI115 and UP2 confer host immunity to specific phages.
a PICMI115 greatly affected the infection outcome by the phage Φ511. Vibrio strain V511 (wt) and transductants carrying the full satellite marked by CmR (PICMI115, two clones c1 and c2) were infected with Φ511 at an MOI 10. The bar charts depict the average phage titer with the SEM from three independent experiments, represented by individual dots. The measurements were taken 60 min post-infection of the specified strains or for the equivalent volume of phage added to the culture media without bacteria. The ratio of phage titer in PICMI115+ to PICMI115- strain V511 is noted above the bar chart. b The gene up2 encodes a novel defense system which activity depends on the phage and host genetic background. A plasmid carrying the gene up2 under the control of its native promoter or, as control, the gfp under the constitutive promoter PLAC, were transferred to diverse V. chagasii strains that are susceptible to at least one phage22. Rows represent sequenced Vibrio strains ordered according to the Maximum Likelihood persistent genome phylogeny of V. chagasii (n = 46). Columns represent phages (n = 48) ordered by VIRIDIC clustering dendrogram. Changes in susceptibility related to the presence of UP2 are indicated by a red square (Supplementary Fig. 18). c The susceptibility to UP2 of six phages that belong to the same VIRIDIC family than Φ115 was tested using their original host, i.e., the host used to isolate these phages. Phage titer was determined 60 min post-infection of the host or for the equivalent volume of phage added to the culture media without bacteria. The bar charts display the average phage titer with the SEM from three independent experiments, indicated by individual dots. The ratio of phage titer in UP2 to GFP strains is provided above the bar chart. A one-tailed t-student tests with Log10 transformation reveal that UP2 < GFP with p-values of 0.0112 (Φ511), 0.0004 (Φ191), 0.0091 (Φ217), 0.0250 (Φ455), 0.0294 (Φ120), and 0.1024 (Φ466).
