EFFICIENCY OF DIFFERENT PROTOCOLS FOR Campylobacter jejuni ISOLATION FROM POULTRY MEAT

Abstract Campylobacter jejuni is the main cause of acute bacterial gastroenteritis, and poultry meat is an important agent vehicle. However, the conventional methods for Campylobacter isolation are often not effective and may lead to erroneous results. Thus, this study aimed to evaluate different methods to C. jejuni detection in poultry products. Ground chicken experimentally contaminated with three different dilutions of the microorganism was analyzed with different protocols to C. jejuni isolation: Seeding directly in agars mCCDA, Columbia and blood agar, and after pre-enrichment in Bolton or Brucella broth. The Campylobacter characteristic colonies were identified and compared in order to assess which method was the most effective. The only protocols in which it was possible to recover the microorganism from all the tests were those using the mCCDA agar associated with the Bolton broth or the Brucella broth. These were also the only protocols that allowed the recovery of C. jejuni 24 hours after the experimental contamination with inoculum equal to 100 CFU/25 g. However, the mCCDA agar without the use of pre-enrichment presented an unsatisfactory performance, lower than the other protocols. It is concluded that mCCDA agar with Brucella broth or with Bolton broth pre-enrichment was more efficient for the C. jejuni isolation than the other protocols.

摘要：空肠弯曲菌（Campylobacter jejuni）是急性细菌性胃肠炎的主要致病菌，家禽肉为其重要的传播载体。然而，传统的弯曲菌分离方法往往效果欠佳，易得出错误检测结果。为此，本研究旨在评估不同方法用于禽产品中空肠弯曲菌检测的可行性。将经三种不同稀释度该微生物人工污染的绞碎鸡肉，采用多种空肠弯曲菌分离方案进行检测：直接接种于mCCDA琼脂、哥伦比亚琼脂及血琼脂，以及经Bolton肉汤或布鲁菌（Brucella）肉汤预增菌后再接种。通过对空肠弯曲菌特征菌落的鉴定与比对，以筛选出最有效的分离方案。结果显示，仅采用mCCDA琼脂联合Bolton肉汤或布鲁菌肉汤的方案，可从所有实验组中回收目标菌株；同时，这两种方案也是唯一能在接种量为100 CFU（菌落形成单位，Colony Forming Unit）/25 g的人工污染后24小时内成功分离到空肠弯曲菌的方法。但未经过预增菌的mCCDA琼脂表现不佳，分离效果劣于其他方案。综上，相较于其他分离方案，采用布鲁菌肉汤或Bolton肉汤进行预增菌后结合mCCDA琼脂的方法，对空肠弯曲菌的分离效率更为优异。