Fig. 4: Antimicrobial activity of hybrid phage microgels.

a Schematic image of a phage microgel where the M13 g3p is binding to the tip of the F pilus on the host E. coli. Box on the bottom right: Comparison of the shapes of phage M13 (filamentous), HER262 (long tailed), T7 (short tailed). b Photos of the HER262-embedded hybrid phage microgels patch arrays forming lysis zones on the lawn of both E. coli ER2738 and E. coli O157:H7. c HER262-embedded hybrid phage microgels sprayed on the lawn of both E. coli ER2738 and O157:H7, showing clearing zones on both lawns. d Titer count of E. coli O157:H7 incubated in PBS after 9 h at different initial concentration with (n = 5 independent experiments per bacterial concentration) and without (n = 3 independent experiments per bacterial concentration) HER262 microgels. (p < 0.0001 for all 5 bacterial concentrations). e Kill curves for E. coli O157:H7 suspension, incubated in TSB for 9 h at different initial concentration with and without HER262 microgels (n = 3 independent experiments per bacterial concentration). f Final titer count of the E. coli O157:H7 incubated in TSB with (n = 5 independent experiments per bacterial concentration) and without (n = 3 independent experiments per bacterial concentration) HER262 microgels after 9 h in part e. g Left: Schematic image of microgel sprays decontaminating multidrug-resistant E. coli O157:H7 in lettuce. Right: pictures of lettuce and meat. White boxes indicate where we cut the lettuce and meat into small pieces. h Left: pictures of wrapped artificially contaminated lettuces sprayed with water and microgels, respectively, at 0 and 9 h. Right: bacterial titer count of the collected bacterial suspension from contaminated lettuces (n = 12 independent lettuces per group). i Left: pictures of wrapped artificially contaminated meats sprayed with water and microgels, respectively, at 0 and 9 h. Right: bacterial titer count of the collected bacterial solution from the contaminated meat (n = 12 independent meat per group). Date are presented as mean ± SD. Box plots show minimum to maximum (whiskers), 25–75% (box), median (band inside) with all data points. Statistical significance is derived from unpaired t-test in panel d–f, and two-way analysis of variance (ANOVA) in panel h–i. ****p < 0.0001. Schematics created with BioRender.com.