Genetic Detection of Harmful Algae Bloom Organisms in the Southern California Coastal Waters
Authors:Faustino Becerra, Joseph Canas, Madonna Chico , Harold DeCastro, Patrick Freymuth, Theodore Peterson, Tiffany Sidwell
Mentor:Dr. James Harber, Associate Professor of Microbiology, Cell Biology and Biotechnology, Oxnard College
There is an alarming increase in the frequency of harmful algae blooms (HABs) on the Southern California coast that lead to poisoning of fish, seizures in marine mammals and Amnesic Shellfish Poisoning in Humans. Genetic detection of the toxin-producing microorganisms from Ventura County and adjacent regions of Los Angeles and Santa Barbara Counties was performed in this research from seashore-collected samples. HABs detected of Pseudo-nitzschia naturally produce the neurotoxin domoic acid and Lingulodininum polyedrum produce yessotoxin. Genetic detection of the harmful organisms in the ocean also included antibiotic resistant bacterial populations. This provided the ability to further interpret the symbiotic relationship between the toxic, naturally occurring eukaryotes and the terrestrially derived antibiotic resistant bacteria. Conventionally, the oceanic bacterial populations are thought to provide the basis for the HABs. So, the findings of common terrestrial based beta-lactamase genes in a wide variety of gram +/- bacterial species were not expected. Methods of genetic detection of the toxic planktonic algae was defined in a protocol of seawater filtration, DNA extraction/ purification/ quantitation and real- time polymerase chain reaction (RT-PCR) amplification. Fecal Coliform membrane assays of seawater, replica plating onto antibiotic containing media and further single colony isolation provided the feedstock for antibiotic gene (beta-lactamase) detection by RT-PCR. The terrestrial beta-lactamase (ampicillin resistance) gene was found on plasmids in at least eight different oceanic bacterial species, indicating that horizontal gene transfer had occurred. Further research to study the timing of HABs and the maintenance of coastal bacterial populations are warranted. Ultimately, the development of a network of shore-communicating sea-faring devices that are capable of performing seawater filtration, DNA extraction and PCR amplification of target sequences could be designed using the genetic biomarkers utilized in this research.