Antibiotic resistance increases in dolphins, in the image of humans

Antibiotic resistance is one of the biggest public health problems in the world, as many common bacterial infections develop resistance to drugs used to treat them, and new antibiotics are not developed quickly enough to combat this problem. .

Formerly largely confined to health care facilities, these resistant bacterial strains are commonly found in other areas, including marine environments. To date, few studies have looked at long-term trends in antibiotic resistance in pathogens isolated from wild animal populations.

Researchers from Florida Atlantic University's Harbor Branch Oceanographic Institute, in collaboration with Georgia Aquarium, University of Medicine South Carolina and Colorado State University, conducted a unique long-term study (2003 to 2015) on antibiotic resistance among pathogens isolated from dolphins truncatus) in the lagoon of Indian River Florida. This lagoon has an important coastal human population and significant environmental impacts.

"In 2009, we reported a high prevalence of antibiotic resistance in wild dolphins, which was unexpected," said Adam M. Schaefer, MPH, senior author and epidemiologist at the FAU branch in Harbor. "Since then, we have been tracking changes over time and have seen a significant increase in antibiotic resistance in isolates of these animals, a trend that reflects reports from health care facilities." According to our findings, it is likely that these isolates come from dolphins, from a source where antibiotics are used regularly, likely to enter the marine environment through human activities or releases from land-based sources. "

Using 13-year data and the Multiple Antibiotic Resistance Index (MAR), the researchers obtained a total of 733 pathogen isolates from 171 individual-nosed dolphins. . Many of the organisms isolated from these animals are important human pathogens.

Results of the study, published in the journal Aquatic mammals, shows that the overall prevalence of resistance to at least one antibiotic for the 733 isolates was 88.2%. The prevalence of resistance was highest with erythromycin (91.6%), followed by ampicillin (77.3%) and cephalothin (61.7%). This is one of the few studies to use the MAR index for bacterial isolates of a marine mammal species.

Resistance to ciprofloxacin among E isolates. Coli more than doubled between sampling periods, reflecting recent trends in clinical infections in humans. Pseudomonas aeruginosa, responsible for infections of the respiratory system, urinary tract infections, among others, was the highest of all organisms and increased during the period of the study.

The MAR index increased significantly between 2003-2007 and 2010-2015 for P. aeruginosa and Vibrio alginolyticus, a common pathogenic marine Vibrio species that has been shown to cause severe seafood poisoning. For all bacterial isolates, resistance to cefotaxime, ceftazidime and gentamicin increased significantly between sampling periods.

"The health and environmental risk assessment or HERA project has found that emerging bacterial resistance to antibiotics in bottlenose dolphins is widespread." "Bottlenose dolphins are a valuable sentinel species that helps us to understand how this affects human health and environmental health.By HERA has been able to provide an extensive database of information in order to continue to learn from these awesome animals, "said Gregory D. Bossart, VMD, Ph. D., co-author, executive vice president and chief veterinarian of Georgia Aquarium. "Antibiotic resistance is one of the most important risks to public health.As resistance increases, the likelihood of successfully treating infections caused by common pathogens decreases."

Sampling for the study was conducted and funded in part by the Florida Specialty License Plate Fund and the Georgia Aquarium, with Bossart as the lead and license holder of HERA. Samples taken from the swab for microbiology were collected in the vent, gastric fluid and feces, and then grown on standard support under aerobic conditions. The most frequently isolated pathogens were Aeromonas hydrophila, E. coli, Edwardsiella tarda, V. alginolyticus and S. aureus, pathogens frequently associated with aquatic environments. The dolphins were caught and released in the Indian River lagoon as part of the HERA project. Sampling took place in June and July of each year.

"The impact of the pathogen Acinetobacter baumannii on human health is a major concern as it is an important nosocomial pathogen whose rates of infection are high. Infection has increased over the past 10 years, "said Peter McCarthy, Ph.D., co-author, professor, and researcher. an associate director for education at the Harbor Branch of the FAU. "In addition to nosocomial infections, resistant strains associated with fish and fish farming have been reported around the world.The high MAR index for this isolated bacteria in dolphins in the Indian River lagoon is a problem important public health. "

Every year in the United States, at least 2 million people become infected with antibiotics and at least 23,000 people die.

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