整鸡中弯曲菌定量检测方法的建立与优化

Development and optimization of enumeration for Campylobacter species

中文关键词:  弯曲菌  抗生素  整鸡  定量检测

英文关键词:Campylobacter  antimicrobial  chicken carcass  quantitative enumeration

中文摘要:

      目的 建立一种简便、灵敏、稳定的整鸡中弯曲菌定量检测方法, 并用北京地区市售整鸡样品进行验证。方法 分别对37株鸡肉中常污染的背景杂菌、24株弯曲菌菌株进行抗生素敏感性测试, 对弯曲菌分离用选择性培养基及抗生素添加剂进行优化和改进; 用77份人工定量污染弯曲菌的鸡淋洗液进行添加回收实验, 以生长指数评价选择性平板对鸡肉样品中背景杂菌的抑制情况和弯曲菌生长状况影响。结果 在改良后的Karmali和Preston选择性平板上, 弯曲菌生长状态稳定, 并可有效抑制鸡肉样品中常见的背景干扰杂菌的生长繁殖, 此方法对鸡肉中弯曲菌检出的灵敏度可达2.5 CFU/g。结论 所建方法灵敏度高、操作简便、计数准确, Karmali和Preston平板组合后可有效提高鸡肉中弯曲菌的检出率, 适用于禽类食品中弯曲菌的定量检测。

英文摘要:

      Objective To establish a simple, sensitive, and stabile quantitative enumeration method for Campylobacter spp. from chicken carcass, and to evaluate it by application in detection of Campylobacter species from retail chicken in Beijing. Methods Based on the plate counting theory, the method of enumeration for Campylobacter species was developed. A total of 37 strains of indigenous ?ora and 24 strains of Campylobacter were used for antimicrobial susceptibility testing, and the selective culture and antibiotic supplements were optimized. Totally, 77 samples with artificial contamination with Campylobacter were evaluated. Growth index was employed for evaluating the growth of Campylobacter as well as the inhibition of indigenous ?ora in plates. Results Campylobacter spp. grew well and was not inhibited by any antibiotic in selective plates, but indigenous ?ora could be inhibited on the modified Karmali and Preston plates. The limit of enumeration for Campylobacter species from chicken was 2.5 CFU/g. Conclusion The method could be applied to detect the Campylobacter species in food specifically, quantitatively and accurately. Preston selective agar in combination with Karmali could improve the detection of Campylobacter species from chicken carcass.