INVESTIGATION OF THE ROLES OF TOXIN-COREGULATED PILI AND MANNOSE-SENSITIVE HEMAGGLUTININ PILI IN THE PATHOGENESIS OF VIBRIO-CHOLERAE O139 INFECTION

In this study, adult volunteers were fed tcpA and mshA deletion mutant s of V, cholerae O139 strain CVD 112 to determine the role of toxin-co regulated pill (TCP) and mannose-sensitive hemagglutinin (MSHA) in int estinal colonization, Eight of 10 volunteers who received CVD 112 or C VD 112 Delta mshA shed the vaccine strains in their stools; the geomet ric mean peak excretion for both groups was 1.4 x 10(5) CFU/g of stool . In contrast, only one of nine recipients of CVD 112 Delta tcpA shed vibrios in his stool (P < 0.01); during the first 24 h after inoculati on, 3 x 10(2) CFU/g was recovered from this volunteer, All recipients of CVD 112 and 8 (80%) of the recipients of CVD 112 Delta mshA develop ed at least a fourfold rise in vibriocidal titer after immunization. I n contrast, only one (11%) of the nine recipients of CVD 112 Delta tcp A developed a fourfold rise in vibriocidal titer (P < 0.01), We conclu de that TCP are an important colonization factor of V, cholerae O139 a nd probably of El Tor V. cholerae O1, In contrast, MSHA does not appea r to promote intestinal colonization in humans.