Researchers have identified three previously unknown genotypes of Helicobacter bacteria living inside pygmy sperm whales.
The work was carried out by a team from Florida Atlantic University’s Harbor Branch Oceanographic Institute with other collaborators.
The research improves our understanding of these elusive creatures, which are rarely seen free swimming in the wild. In fact, most of what we know about pygmy sperm whales comes from specimens that have been stranded predominantly along the southeastern coast of the United States.
According to Annie Page, the study’s senior author and an associate research professor and clinical veterinarian at FAU Harbor Branch:
“Helicobacter bacteria have long been associated with gastrointestinal disorders in humans and other animals, including chronic gastritis, ulcers, and even gastric cancer. To find novel strains of these bacteria in a deep-diving whale species is intriguing.”
While Wendy Marks, corresponding author and a research coordinator of the marine wildlife veterinary medicine and research lab at FAU Harbor Branch, added:
“Two of the genotypes, Kogia Helicobacter 1 and 2, are genetically similar to known Helicobacter species previously found in other cetaceans – such as dolphins and porpoises – and in humans. But Kogia Helicobacter 3 belongs to a more divergent lineage, which emphasizes the possibility that there are far more undiscovered bacteria in the ocean than we realize.”
Page added, describing the standard whales:
“All four whales that tested positive for Helicobacter had visible gastric pathology.. We saw signs of gastritis, gastric ulcers, fibrosis and nematode infestations. In one case, there was also colitis, which suggests that the infection may not be limited to the stomach. While Helicobacter wasn’t listed as the cause of death in any of the whales, these lesions raise questions about its role in gastrointestinal disease.”
On the importance of the research, she said:
“This research underscores the value of long-term marine mammal stranding response programs. Without the ability to study these stranded animals over decades, we never would have discovered these bacteria. Every whale tells a story, and sometimes that story leads us into entirely new scientific territory.”
