RRC ID 50839
著者 Teramura H, Sota K, Iwasaki M, Ogihara H.
タイトル Comparison of the quantitative dry culture methods with both conventional media and most probable number method for the enumeration of coliforms and Escherichia coli/coliforms in food.
ジャーナル Lett Appl Microbiol
Abstract Sanita-kun™ CC (coliform count) and EC (Escherichia coli/coliform count), sheet quantitative culture systems which can avoid chromogenic interference by lactase in food, were evaluated in comparison with conventional methods for these bacteria. Based on the results of inclusivity and exclusivity studies using 77 micro-organisms, sensitivity and specificity of both Sanita-kun™ met the criteria for ISO 16140. Both media were compared with deoxycholate agar, violet red bile agar, Merck Chromocult™ coliform agar (CCA), 3M Petrifilm™ CC and EC (PEC) and 3-tube MPN, as reference methods, in 100 naturally contaminated food samples. The correlation coefficients of both Sanita-kun™ for coliform detection were more than 0·95 for all comparisons. For E. coli detection, Sanita-kun™ EC was compared with CCA, PEC and MPN in 100 artificially contaminated food samples. The correlation coefficients for E. coli detection of Sanita-kun™ EC were more than 0·95 for all comparisons. There were no significant differences in all comparisons when conducting a one-way analysis of variance (anova). Both Sanita-kun™ significantly inhibited colour interference by lactase when inhibition of enzymatic staining was assessed using 40 natural cheese samples spiked with coliform. Our results demonstrated Sanita-kun™ CC and EC are suitable alternatives for the enumeration of coliforms and E. coli/coliforms, respectively, in a variety of foods, and specifically in fermented foods.
SIGNIFICANCE AND IMPACT OF THE STUDY:Current chromogenic media for coliforms and Escherichia coli/coliforms have enzymatic coloration due to breaking down of chromogenic substrates by food lactase. The novel sheet culture media which have film layer to avoid coloration by food lactase have been developed for enumeration of coliforms and E. coli/coliforms respectively. In this study, we demonstrated these media had comparable performance with reference methods and less interference by food lactase. These media have a possibility not only to be useful alternatives but also to contribute for accurate enumeration of these bacteria in a variety of foods, and specifically in fermented foods.
巻・号 65(1)
ページ 57-65
公開日 2017-7-1
DOI 10.1111/lam.12744
PMID 28419503
MeSH Agar / chemistry Colony Count, Microbial / methods* Culture Media / chemistry* Culture Techniques Escherichia coli / growth & development* Food Contamination / analysis* Food Microbiology / methods* Lactase / metabolism
IF 1.471
引用数 4
リソース情報
一般微生物 JCM 1684 JCM 1659 JCM 1232 JCM 1234 JCM 1473 JCM 1666 JCM 1665 JCM 1662 JCM 1681 JCM 1238 JCM 1239 JCM 1027 JCM 1656 JCM 1669 JCM 1652