Researchers have found antibiotic-resistant bacteria in seven species of sharks and one redfish species captured in waters off Massachusetts, Florida, Louisiana and Belize. Most of these wild, free-swimming fish harbored several drug-resistant bacterial strains. The study, published in the Journal of Zoo and Wildlife Medicine, found antibiotic-resistant bacteria in every fish species sampled.

Fish that were captured closer to shore and in more populated areas harbored the greatest number and diversity of drug-resistant microbes.

The researchers also found multidrug-resistant bacteria in fish at nearly all of the study sites, said Mark Mitchell, a professor of veterinary clinical medicine at the University of Illinois and senior author of the paper.

In the new study, the researchers looked for and found bacterial resistance to 13 antibacterial drugs in the fish.

Bacteria from sharks off Martha\'s Vineyard in Massachusetts and in offshore Louisiana were resistant to the fewest number of antibiotics, while sharks in the Florida Keys and Belize harbored bacteria that were resistant to amikacin, ceftazidime, chloramphenicol, ciprofloxacin, doxycycline, penicillin, piperacillin, sulfamethoxazole and ticarcillin. Redfish in the Louisiana offshore site hosted more varieties of drug-resistance than sharks in the same waters. This may reflect differences in their feeding or migratory habits, Mitchell said.

Source: Diana Yates, Illinois News Bureau. Read the full story.