Molecular Probes for Bacterial Vectors in Ciguatera Sea Food Poisons

EPA Grant Number: R823568
Title: Molecular Probes for Bacterial Vectors in Ciguatera Sea Food Poisons
Investigators: Nadathur, Govind S. , Tosteson, Thomas R.
Institution: University of Puerto Rico - Mayaguez
EPA Project Officer: Hiscock, Michael
Project Period: October 1, 1995 through September 1, 1998
Project Amount: $222,569
RFA: Exploratory Research - Minority Institutions (1995) Recipients Lists
Research Category: Water , Land and Waste Management , Ecosystems , Air , Aquatic Ecosystems


The objectives of this project are: (1) to construct species specific probes to identify and enumerate bacteria associated with the toxic benthic dinoflaglellate Ostreopsis lenticularis, (2) to use these probes to correlate the presence of these bacteria with toxicitiy in both laboratory cultured and wild Ostreopsis cells collected in the field, and (3) to use non-transcribed spacer sequences to establish a rapid technique for the identification of these bacteria in mixed cultures.

Associated bacterial flora will be isolated from cultured and field collected Ostreopsis cells. In addition, bacteria present in the surrounding seawater and strains associated with invertebrate reef fauna will be isolated for comparative studies. Bacterial strains will be identified to at least the generic level. Two basic approaches will be taken. The first entails the sequence analysis of the hypervariable region of the small subunit ribosomal RNA genes of isolated bacteria and the establishment of olideoxynucleotide probes for sequences unique to each species. The second approach involves the amplification of non-transcribed spacer sequences of the bacteria and setting up a database of the banding patterns of amplified DNA for each species.

Ostreopsis lenticularis is a vector of ciguatera fish poisoning, a public health problem of serious proportion in this area. The toxicity of cultured O. lenticularis is correlated with the presence of specific associated bacterial flora. The long term goal of this project is to characterize the pattern of symbiotic bacterial flora associated with toxicity in benthic dinoflagellates and to design a bioassay to predict the toxicity of dinoflagellates and ciguatoxic seafood based on the presence and abundance of those bacterial species that are the biomarkers of this toxicity.

Supplemental Keywords:

Health, Scientific Discipline, Environmental Chemistry, Health Risk Assessment, Risk Assessments, Environmental Microbiology, benthic dinoflaglellate, ciguatera sea food , field experiments, reef fauna, molecular probes, RNA genes, bacterial vectors, ostreopsis cells, olideoxynucleotide probes

Progress and Final Reports:

  • 1996
  • 1997
  • Final