FIG 3 .
Expression of the K1 capsule in PA45B and isogenic mutants. (A) Cross-brush agar test results, showing K1 phage reactions of PA45B and isogenic kpsD, mprA, rfaH, and typA mutants. The dashed line indicates the line of phage suspension. (B) Measurement of susceptibility to phage lysis following growth in microtiter plates. The OD600 is shown 3 h postinfection. ****, P < 0.0001. Data were obtained from three independent experiments; error bars indicate standard deviations. Statistical analysis was performed using an unpaired, two-tailed t test.