Inhibitory effect of sulfamonomethoxine on capsule formation of Bordetella bronchiseptica.

Bordetella bronchiseptica phase I organism possesses a capsule and has the ability to agglutinate with K antiserum, although phase III organism lacks both. The present study examines the effect of sulfamonomethoxine (SMMX) on capsule formation of B. bronchiseptica. I also investigated whether or not the organisms possessed a capsule by bacterial agglutination with K antiserum. Three SMMX-resistant strains of B. bronchiseptica phase I organisms showed loss of agglutinability with K antiserum by culturing them at a higher concentration of 1.56 micrograms/ml of SMMX. These results indicated that capsule formation of SMMX-resistant B. bronchiseptica is inhibited by SMMX.