MICROTITER PLATE ADHERENCE ASSAY AND RECEPTOR ANALOGS FOR MYCOPLASMA-HYOPNEUMONIAE

A microtiter plate adherence assay for Mycoplasma hyopneumoniae was es tablished by use of purified swine tracheal cilia which contained rece ptors for the mycoplasmas. M. hyopneumoniae bound specifically to plat es coated with solubilized cilia. The binding was dependent on both th e concentration of cilia and the number of mycoplasmas. Dextran sulfat e, heparin, chondroitin sulfate, laminin, mucin, and fucoidan signific antly inhibited the binding of the mycoplasmas. The six inhibitors als o disrupted the adherence of the mycoplasmas to intact ciliated cells. Preincubation with either mycoplasmas or cilia indicated that heparin , mucin, fucoidan, and chondroitin sulfate interacted with the adhesiv e molecules on the surface of the mycoplasmas, while laminin blocked t he receptors in cilia. The basis for the inhibition induced by dextran sulfate was unknown. Treatment of cilia with neuraminidase appeared t o promote adherence of the mycoplasmas, whereas treatment of cilia wit h sodium metaperiodate decreased binding. These results indicate that receptors for M. hyopneumoniae in the ciliated epithelium of the respi ratory tract of pigs are glycoconjugate in nature.