NCCOS Assessment: Monitoring Increases of Amoxicillin Resistance in Coral Mucus Bacteria under Laboratory Conditions at Charleston, SC, 2022-02-01 to 2024-09-30 (NCEI Accession 0306277)

The data set includes data for the development and testing for experiments that measure increases in amoxicillin resistance of bacterial mucus cultures.
MIC (minimum inhibitory concentration) data – These experiments were used to establish the lowest amoxicillin concentration at which no bacteria would grow in liquid cultures. Optical density readings from a spectrophotometer were used to monitor the growth of the coral mucus cultures with higher readings indicative of more growth. The table includes data from two separate replicate experiments using four different amoxicillin concentrations. Once established, concentrations at or below the MIC level were used to regulate the amount of selection pressure applied to cultures.
Standard Growth Curve Data – Standard growth curves were created for coral mucus cultures that were grown at 0 and 40 mg/L amoxicillin over a seven-hour period. The spreadsheet contains, hourly optical density timepoints taken over the seven-hour period. At each timepoint, culture dilutions were also made and plated to agar plates and grown overnight. The optical density readings and the resulting CFU plate counts were paired together to generate the CFU/mL concentration column. This column was then used to create regression line equations for both the 0 and 40 mg/L cultures and that could be used in the future to approximate the cell concentration of a culture from its optical density reading. This was important for culture passaging during multi-day experiments.
Live Coral Data – Data that was used to assess how treating live coral in artificial seawater with an amoxicillin-loaded delivery paste influences antibiotic resistance over a 28-day period. Data in table are the percent resistant colonies (plated to 400 mg/L) out of the total number of colonies plated from the beginning (day 1), middle (day 14) and end (day 28) of the study.
Doubling Time Data – The doubling time of bacteria (the time it takes for a bacterium to divide) was used to access antibiotic resistance levels. Data in the table are optical density readings taken every hour from each treatment over a seven-hour period from the beginning (day 1) and ending (day 28) of the experiment.
Liquid Inhibition Data – Growing coral mucus bacteria with and without amoxicillin, then plating on different levels of selection to gauge levels of amoxicillin resistance. Data in the table are CFU plate counts from a culture grown for 28-days in 0 mg/L amoxicillin and a culture grown for 28-days in 40 mg/L amoxicillin. At the 1, 14 and 28-day timepoints, the two cultures were plated to selective plates containing 0, 100 and 400 mg/L amoxicillin. The average number of CFU that were present for each culture at each plate concentration are presented in the table.
Amoxicillin Leaching Water Quality Data – Data in the table are the pH, temperature and salinity data for each treatment replicate for the 7-day amoxicillin leaching experiment.
Live Coral Challenge Water Quality Data - Data in the table are the pH, temperature and salinity data for each treatment replicate for the 28-day live coral challenge experiment.