Anti-CsbD MAb cross-reactivities to a panel of class 5 adhesins in the ELISAs. MAbs with similar cross-reactivity patterns are grouped together. (A and B) MAbs cross-reactive to the CS17 and CS1 adhesins. (C) MAb cross-reactive to the CFA/I, CS4, CS14, CS17, and CS1 adhesins. (D) MAb cross-reactive to the CFA/I, CS4, CS14, CS1, CS17, and CS2 adhesins. The bars and error bars represent the mean OD values and standard deviations from at least two repeated assays. The dashed lines represent the limit of detection in the anti-CsbD MAb ELISAs, which was the sum of the average PBS background level and three times the standard deviation.