Occurrence of Resistance to Antibiotics and Metals and of Plasmids in Bacterial Strains Isolated from Marine Environments

Tlie resistance patterns to different antibiotics and lieavy metals of bacterial strains isolated firom marine environments (seawater, sediments and shellfishes) were studied. Pseudomonas aeruginosa showed the widest resistance profile, both to antibiotics and metals. In general, the resistance profiles of Gram-negative I microorganisms include the resistance to arsenic, copper, amoxycillin and tetracydine. Some associations of resistance to different antimicrobial agents were frequently observed. An important proportion of the studied strains harboured plasmids; and the association between the occurrence of plasmids and the resistance to arsenic, amoxycillin, carbencillin and streptomycin was observed.