The effect of co-culture on Stx2 production and release of bacteriophages.

(A) Stx2 production by EHEC NIPH-11060424 was measured by reverse passive latex agglutination (RPLA) test. EHEC NIPH-11060424 was co-cultured with B. thetaiotaomicron, using different initial bacterial concentrations. The reciprocal of the highest twofold serial dilution causing latex agglutination was recorded as the titre. Data represent means ± standard errors of the mean (SEM) from three independent experiments. (B) Plaque assay demonstrating production of fewer bacteriophages when EHEC NIPH-11060424 was co-cultured with B. thetaiotaomicron compared to pure culture.