WORLD
WILD SHARKS, REDFISH HARBOR ANTIBIOTIC-RESISTANT BACTERIA
Baku, July 28 (AZERTAC). Researchers have found antibiotic-resistant bacteria in seven species of sharks and redfish captured in waters off Belize, Florida, Louisiana and Massachusetts. Most of these wild, free-swimming fish harbored several drug-resistant bacterial strains. 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 a senior author of the paper.
"Ultimately the idea of this study was to see if there were organisms out there that had exposures or resistance patterns to antibiotics that we might not expect," Mitchell said. "We found that there was resistance to antibiotics that these fish shouldn`t be exposed to." In the new study, the researchers looked for and found bacterial resistance to 13 antibacterial drugs in the fish. Patterns of resistance varied among the sites.
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 age (the redfish were more mature than the sharks), feeding or migratory habits, Mitchell said. "There are estimates of over 100,000 deaths from infections in hospitals per year, many of them from antibiotic-resistant organisms," Mitchell said. "And we`re creating even more of these organisms out in the environment. People do eat sharks and redfish, Mitchell said, and now these fish represent a potential new route of exposure to drug-resistant bacteria. Sharks and redfish also are predators, and so may function as sentinels for human health.
This study was the thesis for first author Jason Blackburn, a former master`s student at Louisiana State University now on the faculty at the University of Florida.