[show abstract][hide abstract] ABSTRACT: An indirect immunofluorescence approach was developed using semiconductor quantum dot nanocrystals to label and detect a specific bacterial serotype of the bacterial human pathogen Vibrio parahaemolyticus, attached to small marine animals (i.e. benthic harpacticoid copepods), which are suspected pathogen carriers. This photostable labeling method using nanotechnology will potentially allow specific serotypes of other bacterial pathogens to be detected with high sensitivity in a range of systems, and can be easily applied for sensitive detection to other Vibrio species such as Vibrio cholerae.
[show abstract][hide abstract] ABSTRACT: Attached bacteria inhabit the surfaces of many marine animals — a process that may play important roles in the survival and transport through aquatic systems. However, efficient detection of these bacteria has been problematic, especially small aquatic animals such as benthic harpacticoid copepod. Quantum dots (QD) have recently emerged as a significant tool in immunofluorescence detection because of their unique properties compared to other fluorescent probes.In the present study, a polyclonal antibody was raised against the Gram-negative marine bacterium, Alteromonas sp. A microplate-based immunofluorescence bioassay using QD strepavidin conjugates was developed for quantifying putative Alteromonas sp. cells located on the surfaces of a marine harpacticoid copepod, Microarthridion littorale. The number of attached Alteromonas sp. was estimated to be 102 ± 8 CFU using this method. The QD approach, coupled to a microplate assay can potentially provide an efficient and accurate method for rapidly detecting multiple bacteria species attached to small invertebrate animals because of their unique excitation and emission characteristics.