An interlaboratory study on the detection method for Escherichia albertii in food using real time PCR assay and selective agars.

Autor: Arai S; Division of Microbiology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki 210-9501, Japan., Hirose S; Division of Microbiology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki 210-9501, Japan., Yanagimoto K; Department of Microbiology, Yamanashi Institute of Public Health and Environment, 1-7-31 Fujimi, Kofu, Yamanashi 400-0027, Japan., Kojima Y; Division of Microbiology, Kawasaki City Institute for Public Health, 3-25-13 Tonomachi, Kawasakiku Kawasaki, Kanagawa 210-0821, Japan., Yamaya S; Miyagi Prefectural Institute of Public Health and Environment, 4-7-2, Saiwai-cho, Miyagino-ku, Sendai 983-0836, Japan., Yamanaka T; Research Institute for Environmental Sciences and Public Health of Iwate Prefecture, 1-11-16 Kitaiioka, Morioka 020-0857, Japan., Matsunaga N; Fukuoka City Institute of Health and Environment, 2-1-34, Jigyohama, Chuo-ku, Fukuoka 810-0065, Japan., Kobayashi A; Division of Microbiology, Mie Prefecture Health and Environment Research Institute, 3684-11 Sakura-cho, Yokkaichi 512-1211, Japan., Takahashi N; Shizuoka City Institute of Environmental Sciences and Public Health, 1-4-7 Oguro, Suruga, Shizuoka 422-8072, Japan., Konno T; Akita Prefectural Research Center for Public Health and Environment, 6-6, Senshukubota-machi, Akita 010-0874, Japan., Tokoi Y; Utsunomiya City Institute of Public Health and Environment, 972 Takebayashi-machi, Utsunomiya 321-0974, Japan., Sakakida N; Saitama Institute of Public Health, 410-1 Ewai, Yoshimi-machi, Hiki-gun, Saitama 355-0133, Japan., Konishi N; Department of Microbiology, Tokyo Metropolitan Institute of Public Health, 3-24-1 Hyakunin-cho, Shinju-ku, Tokyo 169-0073, Japan., Hara-Kudo Y; Division of Microbiology, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki 210-9501, Japan; Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho, Fuchu, Tokyo 183-8509, Japan. Electronic address: ykudo@nihs.go.jp.
Jazyk: angličtina
Zdroj: International journal of food microbiology [Int J Food Microbiol] 2024 Apr 02; Vol. 414, pp. 110616. Date of Electronic Publication: 2024 Feb 03.
DOI: 10.1016/j.ijfoodmicro.2024.110616
Abstrakt: Escherichia albertii is an emerging enteropathogen. Although E. albertii-specific detection and isolation methods have been developed, their efficiency on food samples have not yet been systematically studied. To establish a series of effective methods for detecting E. albertii in food, an interlaboratory study was conducted in 11 laboratories using enrichment with modified E. coli broth supplemented with cefixime and tellurite (CT-mEC), real-time PCR assay, and plating on four kinds of selective agars. This study focused on the detection efficiency of an E. albertii-specific real-time PCR assay (EA-rtPCR) and plating on deoxycholate hydrogen sulfide lactose agar (DHL), MacConkey agar (MAC), DHL supplemented with rhamnose and xylose (RX-DHL), and MAC supplemented with rhamnose and xylose (RX-MAC). Chicken and bean sprout samples were inoculated with E. albertii either at 17.7 CFU/25 g (low inoculation level) or 88.5 CFU/25 g (high inoculation level), and uninoculated samples were used as controls. The sensitivity of EA-rtPCR was 1.000 for chicken and bean sprout samples inoculated with E. albertii at low and high inoculation levels. The Ct values of bean sprout samples were higher than those of the chicken samples. Analysis of microbial distribution by 16S rRNA gene amplicon sequencing in enriched cultures of bean sprout samples showed that approximately >96 % of the population comprised unidentified genus of family Enterobacteriaceae and genus Acinetobacter in samples which E. albertii was not isolated. The sensitivity of the plating methods for chicken and bean sprout samples inoculated with a high inoculation level of E. albertii was 1.000 and 0.848-0.970, respectively. The sensitivity of the plating methods for chicken and bean sprout samples inoculated with a low inoculation level of E. albertii was 0.939-1.000 and 0.515-0.727, respectively. The E. albertii-positive rate in all colonies isolated in this study was 89-90 % in RX-DHL and RX-MAC, and 64 and 44 % in DHL and MAC, respectively. Therefore, the sensitivity of RX-supplemented agar was higher than that of the agars without these sugars. Using a combination of enrichment in CT-mEC and E. albertii isolation on selective agars supplemented with RX, E. albertii at an inoculation level of over 17.5 CFU/25 g of food was detected with a sensitivity of 1.000 and 0.667-0.727 in chicken and bean sprouts, respectively. Therefore, screening for E. albertii-specific genes using EA-rtPCR followed by isolation with RX-DHL or RX-MAC is an efficient method for E. albertii detection in food.
Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have influenced the work reported in this article.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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