ANALYSIS OF THE INTERACTION OF AEROMONAS-CAVIAE, AEROMONAS-HYDROPHILAAND AEROMONAS-SOBRIA WITH MUCINS

Aeromonas species are known to be involved in human gastrointestinal d iseases. These organisms colonize the gastrointestinal tract. Aeromona s hydrophila, A. caviae: and A. sobria have been demonstrated microsco pically to adhere to animal cell lines that express mucous receptors, but quantitative studies of adherence to mucosal components such as mu cin have nor-been published to date. Purified bovine submaxillary glan d, hog gastric mucin, and Fish skin mucin were used as a model to stud y mucin-binding activity among A. caviae, A. hydrophila, and A. sobria strains. Our findings revealed that binding of radiolabeled and enzym e-conjugated mucins to Aeromonas cells varied depending on the labelin g procedure. The highest binding was observed when the three mucin pre parations were labeled with horseradish peroxidase. Binding of the var ious horseradish peroxidase-labeled mucins by A. carviae, A. hydrophil a, and A. sobria cells is a common property among Aeromonas species is olated from human infections, diseased fish, and from environmental so urces. The proportion of Aeromonas strains which bind the various hors eradish peroxidase-labeled mucins was significantly higher for A. hydr ophila than for A. carviae and A. sobria. Bacterial cell-surface extra cts containing active mucin-binding components recognized the horserad ish peroxidase-labeled mucins. The molecular masses of the mucin-bindi ng proteins were estimated by SDS-PAGE and Western blot as follows: A. ca vhe strain A4812 (95 and 44 kDa): A. hydrophila strain 48748 (97, 45, 33 and 22 kDa); and A. sobria strain 48739 (95 and 43 kDa). Mucin interaction with Aeromonas cells was also studied in terms of growth i n mucin-rich media. The culture conditions greatly influence the expre ssion of A. hydrophila mucin-binding activity. (C) 1998 Federation of European Microbiological Societies. Published by Elsevier Science B.V.