Scientists Warn Antibiotic Resistance Is Also Impacting Dolphins

A study out of Florida Atlantic University has found that dolphins are increasingly facing antibiotic resistance similar to humans. The research tracked antibiotic resistance related to bottlenose dolphins for 13 years, finding that since initially reporting high resistance in 2009, the degree of antibiotic resistance among wild dolphins has increased significantly.

Samples collected from wild bottlenose dolphins located in Indian River Lagoon in Florida revealed that 88-percent of tested pathogens were resistant to one or more antibiotics. During the time period these samples were studied, the researchers noted that E. coli pathogens more than doubled in their antibiotic resistance.

As well, the researchers found that the majority of pathogens found in samples collected from dolphins were resistant to erythromycin, an antibiotic commonly used for treating conditions ranging from acne to certain STDs. The scientists note that the antibiotic-resistant bacteria found in wild dolphins likely originated from sources where antibiotics are frequently used.

As with humans, these resistant bacteria are difficult to treat using the antibiotics typically used to clear up the conditions. When one of these common treatments are used, the bacteria that isn't resistant to the antibiotics end up dying, leaving behind the resistant antibiotics to grow and spread.

The study's lead author Adam M. Schaefer explained:

In 2009, we reported a high prevalence of antibiotic resistance in wild dolphins, which was unexpected. Since then, we have been tracking changes over time and have found a significant increase in antibiotic resistance in isolates from these animals. This trend mirrors reports from human health care settings. Based on our findings, it is likely that these isolates from dolphins originated from a source where antibiotics are regularly used, potentially entering the marine environment through human activities or discharges from terrestrial sources.