Author
 |
Siragusa, Gregory |
|
Submitted to: Journal of Rapid Methods and Automation in Microbiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/3/1999 Publication Date: N/A Citation: N/A Interpretive Summary: This study validates the use of a previously described method, the Track-Dilution method, as a research tool for conducting large numbers of agar plate culture method plate counts to estimate bacterial populations from animal samples. It is only valid for those samples with a known bacterial population of greater than 100 cfu/ml. Its advantage is that one person can perform the plating of six pre-diluted samples in less than a minute using only one agar plate. Results indicated that the Track-Dilution method was equally as accurate, precise and reproducible as other standard plate count methods for a variety of bacteria from food animal samples. Technical Abstract: A rapid and easy method of obtaining a viable plate count, the Track- Dilution method, was evaluated and compared to Spiral Plating to obtain viable plate counts from ground beef samples and beef carcass surface tissue samples inoculated with salmonellae or Escherichia coli O157:H7. Based on the statistical analysis of the dataset (n = 125 samples), the Track-Dilution method results were not different (p > 0.1) than those obtained from Spiral Plating. Linear correlation of the scatterplot of Spiral Plating and Track-Dilution indicated a high level of agreement between these two methods (r**2 = 0.968). The Track-Dilution method was determined to be both a valid and an efficient means of estimating viable plate counts for meat animal- derived samples with bacterial counts of greater than 100 cfu/ml. |
