Coincident plasmids and atimicrobial resistance in marine bacteria isolated from polluted and unpolluted Atlantic ocean samples

• Published in: Applied and environmental microbiology 1986-01, Vol.51 (6), p.1285-1292
• Main Authors: Baya, A M, Brayton, PR, Brown, V L, Grimes, D J, Russek-Cohen, E, Colwell, R R
• Format: Article
• Language: English
• ISSN: 0099-2240

Four different types of samples were examined for antibiotic resistant bacteria: sewage effluent (unchlorinated) from the Barceloneta Regional Treatment Plant in Puerto Rico; seawater surrounding the Treatment Plant outfall diffuser; seawater surrounding the outfall diffuser of the wastewater treatment plant in Ocean City, Md.; and seawater from unpolluted sites. Bacteria were enriched in marine broth 2216, supplemented with nitrobenzene, o-cresol, m-cresol, quinone, 4-nitroaniline, bis(tributyltin) oxide, or dibutyl phthalate. The MIC was determined for each strain and for all chemicals. A total of 299 strains, all gram-negative rod-shaped bacteria, were isolated and tested for resistance to 9 antibiotics. Sewage effluent, which consisted primarily or pharmaceutical and industrial waste, contained the highest number of antibiotic and chemical resistant strains. Strains isolated from sewage effluent also had the highest numbers of plasmid DNA bands. Isolates from water contaminated by domestic waste showed lower levels of resistance, and strains from clean seawater were the most sensitive to the antibiotics and toxic chemicals. These latter isolates contained smaller numbers of plasmids.