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 2xBPW 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 recover Salmonella.

在家禽饲料中检测沙门氏菌具有挑战性。研究表明，预富集培养基缺乏防止酸性pH的缓冲能力，酸性缓冲导致细胞损伤，死亡或改变生化途径的物质，从​​而无法检测沙门氏菌。已开发出一种碳酸三磷酸酯（TPC）预富集培养基，以在饲料孵育过程中保持接近中性的pH，但尚未证实其在多种饲料和成分中的用途。将五克饲料成分（8种类型）和基于玉米/小麦的家禽饲料（10种类型）样品分别添加至45mL的五种不同的预浓缩肉汤中：乳糖肉汤（LB），缓冲蛋白ept水（BPW）），双缓冲蛋白ept水（2xBPW），通用预富集肉汤（UPB）和TPC。在37°C孵育0、18、24和48小时后，测量每个预富集的pH（5次重复/处理）。通过ANOVA和最小显着性差异T检验分析数据。对于所有原料和饲料，LB，BPW，2xBPW和UPB的初始pH范围为6-7。TPC中原料和饲料的初始pH为8.0-8.4。温育24小时后，LB和BPW的pH降低至4.6-5.5。在2xBPW和UPB中孵育的饲料类型之间存在差异，在24h时pH范围为4.8-6.4。TPC的可变性低于2xBPW或UPB，且24h的pH范围为6.5-7.4。结果表明，TPC中各种饲料的预富集可在整个孵育过程中提供接近中性的pH，并可能提高沙门氏菌的回收能力。