R & F Products, Inc., 2725 Curtiss Street, Downers Grove, Illinois 60188.
(ORCID: https://orcid.org/0000-0003-2187-2476 [P.T.N.]).
J Food Prot. 2021 Jan 1;84(1):160-168. doi: 10.4315/JFP-20-245.
Arcobacter species are gram-negative rods that have been implicated in food- and waterborne illness. Although various cultural isolation methods have been proposed, the current procedures are unable to fully suppress the growth of background microbiota present in food samples, which inhibits Arcobacter isolation. The purpose of this study was to develop a selective enrichment broth and chromogenic plating medium to detect three Arcobacter species that have been recognized as emerging foodborne pathogens: Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii. The developed Nguyen-Restaino-Juárez (NRJ) Arcobacter detection system consists of a selective enrichment broth (NRJ-B) and a selective-differential plating medium (NRJ-M). The protocol of the detection method was determined by evaluating the growth of A. butzleri, A. cryaerophilus, and A. skirrowii under various temperatures (30, 35, and 42°C) and incubation (aerobic, microaerophilic, and anaerobic) conditions. Additionally, 47 Arcobacter strains and 39 non-Arcobacter strains were tested in inclusivity and exclusivity evaluations of NRJ-B and NRJ-M. Overall, the study determined that the optimal growth conditions of Arcobacter species using the NRJ Arcobacter detection system were aerobic incubation at 30°C. NRJ-B supported good growth of A. butzleri, A. cryaerophilus, and A. skirrowii while effectively suppressing the growth of non-Arcobacter strains after 48 h. Furthermore, NRJ-M yielded 97.8% inclusivity and 100.0% exclusivity using the tested strains and resulted in salmon-pigmented Arcobacter colonies (1.0 to 1.5 mm in diameter) after 72 h. The novel protocol is the first to develop a chromogenic plating medium for the isolation of Arcobacter species. This simple and accurate test method would greatly contribute to understanding the distribution of pathogenic Arcobacter species in food samples.
弯曲杆菌属是一种革兰氏阴性杆菌，已被认为与食源性和水源性疾病有关。尽管已经提出了各种文化分离方法，但目前的程序无法完全抑制存在于食物样本中的背景微生物群落的生长，这抑制了弯曲杆菌的分离。本研究旨在开发一种选择性富集肉汤和显色平板培养基，以检测三种已被认为是新兴食源性病原体的弯曲杆菌属：空肠弯曲杆菌、嗜冷弯曲杆菌和斯基罗弯曲杆菌。所开发的 Nguyen-Restaino-Juárez（NRJ）弯曲杆菌检测系统包括选择性富集肉汤（NRJ-B）和选择性差异平板培养基（NRJ-M）。通过评估在不同温度（30、35 和 42°C）和孵育（需氧、微需氧和厌氧）条件下空肠弯曲杆菌、嗜冷弯曲杆菌和斯基罗弯曲杆菌的生长情况，确定了检测方法的方案。此外，对 47 株弯曲杆菌属菌株和 39 株非弯曲杆菌属菌株进行了 NRJ-B 和 NRJ-M 的包容性和排他性评估。总体而言，研究确定使用 NRJ 弯曲杆菌检测系统的弯曲杆菌属最佳生长条件为 30°C 有氧孵育。NRJ-B 支持空肠弯曲杆菌、嗜冷弯曲杆菌和斯基罗弯曲杆菌的良好生长，同时在 48 小时后有效抑制非弯曲杆菌属菌株的生长。此外，NRJ-M 对测试菌株的包容性为 97.8%，排他性为 100.0%，并在 72 小时后产生鲑鱼色弯曲杆菌属菌落（直径 1.0 至 1.5 毫米）。该新方案是首次开发用于分离弯曲杆菌属的显色平板培养基。这种简单而准确的测试方法将极大地有助于了解食源性病原体弯曲杆菌属在食物样本中的分布。
