Fig. 8

Determination of growth rate of phage-resistant bacteria in culturable bacteria targeted by phages in the gut of housefly larvae. To determine the growth rate of phage-resistant bacteria of culturable bacteria targeted by phages in the gut of housefly larvae, phage-resistant bacteria R1 and phage-resistant bacteria R4 were obtained after co-culture of phage and host bacteria for 1 (A) and 4 days (B), respectively. Bacterial growth tests were carried out in NA medium plates under aerobic culture conditions. In the case of phage-resistant R1 bacteria R1, RHB (resistant Y12 [RY12], resistant Ef [REf]) and RBB (resistant EhX [REhX], resistant KX [RKX],resistant Ec [REc], resistant Lf [RLf], resistant Bs [RBs]) were inoculated in LB liquid medium and cultured at 37 °C overnight (OD₆₀₀ > 1.0). Two 6 mm-diameter sterile filter papers were placed symmetrically on both sides of the agar medium, and 10 µl REhX: resistant EhX was added to the filter papers. All plates were cultured at 37 °C and cultured under aerobic conditions for 24, 48, 72, 96 and 120 h, respectively. The growth diameter of bacteria was recorded. Other bacteria were cultured and the growth diameter measured similarly. The growth rate was evaluated by measuring the colony size. The experiments were conducted with three independent biological replications. The data were compared by one-way analysis of variance. LB, Luria-Bertani (negative control); NA, neutral agar; RBB, phage-resistant bacteria of beneficial bacteria; RHB, phage-resistant bacteria of harmful bacteria