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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Poultry Microbiological Safety and Processing Research Unit » Research » Publications at this Location » Publication #379035

Research Project: Production and Processing Intervention Strategies for Poultry Associated Foodborne Pathogens

Location: Poultry Microbiological Safety and Processing Research Unit

Title: Evaluation of tris phosphate carbonate Salmonella pre-enrichment medium for poultry feed and feed ingredients

item RICHARDSON, KURT - Anitox Corp
item Cosby, Douglas
item Berrang, Mark
item Cox, Nelson - Nac
item CLAY, SHANNON - Anitox Corp
item WELLER, CHERYL - Anitox Corp
item HOLCOMBE, NICOLE - Anitox Corp

Submitted to: Journal of Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: Salmonella contamination of feed, feed ingredients, poultry and poultry products continue to be of great concern to the industry and consumers. Detecting Salmonella in poultry feed and feed ingredients is very difficult. This difficulty is partially a result of the harmful environment which forms during the pre-enrichment stage of culturing Salmonella from the feed or ingredient. A recently developed buffer system using three buffers has proven to reduce the harmful environment which develops during pre-enrichment. The purpose of this study was to evaluate this buffer in preventing a harmful pH decrease when various poultry feeds and feed ingredients, readily available, were pre-enriched for Salmonella detection. The buffer system was able to maintain a near neutral pH throughout the incubation period and may improve the ability to detect Salmonella from feed and feed ingredients.

Technical Abstract: Detecting Salmonella in poultry feed is challenging. Studies have shown that pre-enrichment media lack the buffering capacity to prevent an acidic pH which results in cell injury, death or altered biochemical pathways preventing Salmonella detection. A tris phosphate carbonate (TPC) pre-enrichment medium has been developed to maintain a near neutral pH during incubation of feed but it’s utility has not been confirmed for a wide variety of feed and ingredients. Five gram samples of feed ingredients (8 types) and corn/wheat based poultry feeds (10 types) were individually added to 45mL of each of five different pre-enrichment broths: lactose broth (LB), buffered peptone water (BPW), double buffered peptone water (2xBPW), universal pre-enrichment broth (UPB), and TPC. After incubation for 0, 18, 24, and 48 hours at 37°C, the pH of each pre-enrichment was measured (five replicates/treatment). Data were analyzed by ANOVA and least significant difference T-test. The initial pH of the LB, BPW, 2xBPW and UPB ranged from 6 - 7 for all ingredients and feeds. The initial pH of ingredients and feed in TPC was 8.0-8.4. After 24h of incubation, pH had decreased to 4.6-5.5 for LB and BPW. Variability was observed among feed types incubated in 2xBPW and UPB where the pH ranged from 4.8-6.4 at 24h. TPC was less variable than 2xXBPW or UPB with the pH ranging from 6.5-7.4 at 24h. Results suggest that pre-enrichment of a variety of feed in TPC provides a near neutral pH throughout incubation and may improve the ability to detect Salmonella.