Prominent human health impacts from several marine microbes: history, ecology, and public health implications.

This paper overviews several examples of important public health impacts by marine microbes and directs readers to the extensive literature germane to these maladies. These examples include three types of dinoflagellates (Gambierdiscus spp., Karenia brevis, and Alexandrium fundyense), BMAA-producing cyanobacteria, and infectious microbes. The dinoflagellates are responsible for ciguatera fish poisoning, neurotoxic shellfish poisoning, and paralytic shellfish poisoning, respectively, that have plagued coastal populations over time. Research interest on the potential for marine cyanobacteria to contribute BMAA into human food supplies has been derived by BMAA's discovery in cycad seeds and subsequent implication as the putative cause of amyotrophic lateral sclerosis/parkinsonism dementia complex among the Chamorro people of Guam. Recent UPLC/MS analyses indicate that recent reports that BMAA is prolifically distributed among marine cyanobacteria at high concentrations may be due to analyte misidentification in the analytical protocols being applied for BMAA. Common infectious microbes (including enterovirus, norovirus, Salmonella, Campylobacter, Shigella, Staphylococcus aureus, Cryptosporidium, and Giardia) cause gastrointestinal and skin-related illness. These microbes can be introduced from external human and animal sources, or they can be indigenous to the marine environment.

Bacterial production of tetrodotoxin in the pufferfish Arothron hispidus.

This study evaluates the presence, location and production source of tetrodotoxin (TTX) in two species of pufferfish, Diodon histrix and Arothron hispidus, common to Hawaiian waters. Organs from each fish were analysed for TTX and used to isolate bacteria for evaluation of possible TTX production. Comparative analyses of extracts of fish and bacterial culture media were performed with liquid chromatography-mass spectrometry (LC-MS) and a sodium channel specific bioassay. Bacterial cultivation experiments were performed in two different growth media and bacteria were identified through sequence homology of the 16S rRNA gene. Forty-two and forty-seven distinct strains were cultivated from D. histrix and A. hispidus, respectively. However, no commonality was found between the populations of bacteria isolated from the two fish. TTX was detected only in A. hispidus and was present in the flesh, pectoral fin and kidneys, as well as the skin slime. Sixteen of the forty-seven bacterial species isolated from A. hispidus were cultivated for further evaluation of TTX production. Among these sixteen bacterial species, Vibrio harveyi strains isolated from the skin slime and kidneys of A. hispidus were found to produce TTX, being the source of TTX produced in the pufferfish.