Fig. 8

a: Western blot of IgA1 protease in a collection of serogroup W and Y isolates and compared to a serogroup B isolate (MC58). A mutant strain, Δiga, was used as a negative control [6]. The IgA1 protease consisting of the IgaP and Igaα domains generates a protein of size 150 kDa in MC58. An IgA1 protease consisting of only the IgaP domain results in a protein with a size of 100 kDa in MC58. The serogroup W isolates generated a protein that was smaller than 150 kDa. b: PCR amplified Igaα domains of serogroup W and Y isolates compared to MC58, which has a complete Igaα domain. The complete Igaα domain of MC58 has a size of approximately 1.5 kb while the serogroup W and Y isolates are smaller, approximately 0.9 kb. The serogroup Y isolates seem to have a slightly smaller Igaα domain than serogroup W