Dispersal of potentially pathogenic bacteria by plastic debris in Guanabara Bay, RJ, Brazil

Analyses of thermotolerant coliform and heterotrophic bacteria as well as Escherichia coli and Vibrio species were carried out on plastic samples and in the surrounding waters of Guanabara Bay to evaluate plastic debris as vehicles of bacterial dispersal. Chemical characterizations of plastics were performed using Fourier transform infrared spectroscopy (FTIR). Plastic debris with high coliform contents were found, while their respective water samples had only low titers. No correlations were observed, however, between the amounts of bacteria and the chemical compositions of the plastic debris. Forty-four bacterial strains were PCR-confirmed as E. coli pathotypes, and 59 strains of Vibrio spp. (with 12 being identified as Vibrio cholerae [6], Vibrio vulnificus [5], and Vibrio mimicus [1]). These findings suggest these plastics can function as a substrate for bacterial biofilms (including pathogens). These debris, in turn, can be dispersed in aquatic environments not otherwise showing recent fecal bacterial contamination. •First study that relates plastic and microorganisms in the Bay of Guanabara, Brazil.•Escherichia coli were confirmed by PCR as EHEC or EPEC, EIEC, EAEC and EHEC in waste and water.•One Vibrio mimicus, 6 Vibrio cholerae, and 5 Vibrio vulnnificus were found in waste water.•Some plastic wastes presented strains not detected in the surrounding water.•The results indicate that plastic wastes can disperse potentially pathogenic bacteria.