Comparing the Behavior of Multidrug-Resistant and Pansusceptible Salmonella during the Production and Aging of a Gouda Cheese Manufactured from Raw Milk

Author:

D'AMICO DENNIS J.1,DRUART MARC J.2,DONNELLY CATHERINE W.3

Affiliation:

1. 1Department of Animal Science, University of Connecticut, 3636 Horsebarn Hill Road, Storrs, Connecticut 06269

2. 2Emmi Roth USA, Inc., 645 Bartlett Hill Road, Berlin, Vermont 05602

3. 3Department of Nutrition and Food Sciences, University of Vermont, 109 Carrigan Drive, Burlington, Vermont 05405, USA

Abstract

Outbreaks of salmonellosis have been linked to the consumption of cheese, and emerging multidrug-resistant (MDR) strains of Salmonella may be more virulent and more tolerant than less resistant strains to stresses encountered in food production, which may enhance the survival of these resistant strains in cheese. This study was conducted to compare the behavior of MDR and pansusceptible Salmonella strains during the manufacture and aging of Gouda cheese and compare pathogen recovery via several rapid and traditional methods. Cheeses were manufactured from raw milk inoculated with a six-strain cocktail of either MDR or susceptible Salmonella Newport and Salmonella Typhimurium at initial levels of ~20 CFU/ml. Samples of milk, whey, curd, and finished cheese were analyzed using eight enrichment and detection protocols. Overall, changes in pathogen levels observed throughout manufacture and aging did not differ significantly between MDR and susceptible Salmonella strains. Salmonella counts increased significantly during manufacture to a mean of 734 CFU/g on day 1 followed by a significant decrease over 60 days of aging to <1 CFU/g. Although levels fell and stayed below the direct plating detection limit of ≥5 CFU/g after 54 days on average, viable cells remained detectable after enrichment for an average of 210 ± 40 days. The International Organization for Standardization methods with and without PCR detection provided the most accurate results, and the remaining methods, notably those with selective primary incubation, produced results that disagreed significantly with the true result. Overall, our findings suggest that MDR Salmonella strains may not pose a greater threat to cheese safety than do non-MDR Salmonella strains.

Publisher

International Association for Food Protection

Subject

Microbiology,Food Science

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3