ATTACHMENT OF NON-CULTURABLE TOXIGENIC VIBRIO-CHOLERAE-O1 AND NON-O1 AND AEROMONAS SPP TO THE AQUATIC ARTHROPOD GERRIS-SPINOLAE AND PLANTS IN THE RIVER-GANGA, VARANASI

Non-cultivable, pathogenic O1 and non-O1 Vibrio cholerae and Aeromonas spp. were resuscitated from aquatic arthropods and plant homogenate r espectively, by rabbit ileal loop (RIL) assay. These organisms adhered to the aquatic arthropod Gerris spinolae and various species of phyto plankton in the River Ganga, but failed to grow after direct inoculati on on artificial media except for only 10 homogenates of the arthropod . The number of non-O1 V. cholerae and Aeromonas recovered on direct i noculation of G. spinolae homogenates were in the order of 10(5)-10(6) whereas those of the Ganga water were 10(2)-10(3) ml(-1). A total of 119 strains of O1 and non-O1 V. cholerae and Aeromonas spp. (69 isolat es from G. spinolae and 50 from aquatic plants) were recovered from th e loop contents. The results indicate that production of the enzyme ch itinase by O1 and non-O1 V. cholerae and Aeromonas spp. might facilita te their adsorption and multiplication on different species of zoo- an d phyto-plankton. Most of the isolates were enterotoxic, haemolytic an d resistant to different antibiotics. This study suggests that species of zoo- ana phyto-planktons, until now not reported to be associated with O1 and non-O1 V. cholerae, may act as reservoirs of these organis ms as well as different species of Aeromonas in a fresh-water riverine ecosystem.