Serum Antibodies Protect against Intraperitoneal Challenge with Enterotoxigenic Escherichia coli

Figure 5

The sera from the CFA/I-immunized mice are effective in killing wt CFA/I⁺ ETEC H10407 but not K99⁺ ETEC B41. The sera of the 60 μg CFA/I-immunized mice were compared to those from sPBS-dosed mice (Figure 2) for bactericidal activity serially diluted (a, e) 2-, (b, f) 4-, (c, g) 8-, and (d, h) 16-fold. Depicted are the percentages of the survival bacterial CFU relevant to the initial bacterial CFU before supplement of sera (time = 0 min). At 20, 40, and 60 min after incubation, the bacterial survival rates were statistically calculated between anti-CFA/I sera and the -sPBS sera via Student’s 𝑡-test: *𝑃<0.05, **𝑃<0.01, and ***𝑃<0.001. Values are the mean ± SEM (𝑛=3).

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