The Bacteriological Analytical Manual (6th edition) specifies use of glucose-salt-teepol (GST) broth for detection of Vibrio vulnificus and other halophilic vibrios in seafood. Since teepol is no longer commercially available, this study compared five enrichment broths for their ability to recover V. vulnificus. Ten samples of seeded oysters were analyzed using a three-tube MPN and enriched in each of five broths in duplicate. Broth cultures were then streaked onto cellobiose-polymyxin B-colistin (CPC) agar and sodium dodecyl sulfate-polymyxin B-sucrose (SDS) agar plates. Average (± standard error) recovery (log MPN/g) from each broth was as follows: Alkaline-peptone-water (APW), 4.16 ± 0.20; Marine (MRN) broth, 3.63 ± 0.16; Horie's broth, 2.88 ± 0.17; Monsur's broth, 2.43 ± 0.16; and GST broth, 1.28 ± 0.28. APW and MRN broths yielded significantly (P<0.05) higher recovery than other broths by the Kruskal-Wallis nonparametric rank test. Vibrio vulnificus was isolated with higher frequency from CPC (81%) as compared with SDS (61%) agar plates. Background growth was minimal on CPC agar, facilitating selection of V. vulnificus colonies. Based on these results, APW enrichment broth and CPC isolation agar were more efficient for recovery of V. vulnificus from oysters than other broth and agar combinations

This study compares recoveries of Vibrio parahaemolyticus and Vibrio vulnificus with salt-polymyxin B broth (SPB) and alkaline peptone water (APW) from samples of crab legs, oysters, shrimp, lobster and shark, which were inoculated at three levels (approximately 101 to 102, 102 to 103 and 104 to 105/g) with each of the pathogens. Six samples of each product were analyzed [3-tube most probable number (MPN)] with each broth. Inoculated samples of oysters and slurries of crab and lobster were also tested after cold stress (refrigerated at 2 to 4°C, 3 or 7 days, or frozen at −15°C for 21 or 28 days). For each seafood, geometric means of cells recovered with APW were significantly (P < 0.05) higher than the corresponding means of recovery with SPB. In addition, 12 of 15 calculated estimates of 50% relative detectable levels (RDL50) were lower (P < 0.05) for APW than for SPB. In these samples, the level of detection by APW was found to be 40 to 32,000 and 6- to 42-fold lower for V parahaemolyticus and V. vulnificus, respectively, than the level of detection by SPB. In cold-stored samples, overall detection of the pathogens was greatly reduced, but APW was also more efficient than SPB in recovering stressed cells.