Levels and Distribution of Salmonella in Naturally Contaminated Cashews
Raw materials associated with foodborne illness outbreaks are rarely available for evaluation. The levels and distribution of Salmonella were determined in naturally contaminated raw cashews linked to a salmonellosis outbreak associated with a fermented cashew cheese analog. Two unopened 22.7-kg box...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-08-01
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| Series: | Journal of Food Protection |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0362028X23067819 |
| _version_ | 1797773636889739264 |
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| author | Hanna Louvau Linda J. Harris |
| author_facet | Hanna Louvau Linda J. Harris |
| author_sort | Hanna Louvau |
| collection | DOAJ |
| description | Raw materials associated with foodborne illness outbreaks are rarely available for evaluation. The levels and distribution of Salmonella were determined in naturally contaminated raw cashews linked to a salmonellosis outbreak associated with a fermented cashew cheese analog. Two unopened 22.7-kg boxes from a single lot of cashew kernel pieces were each divided into seven approximately equal units, 14 in total. Three 10-g subsamples per unit (n = 21) were evaluated for aerobic plate count (APC), coliform counts, and Escherichia coli counts, and 10 50-g subsamples per unit (n = 70) were enriched for the presence of Salmonella. Presumptive Salmonella-positive colonies were confirmed using CHROMagar Salmonella and real-time PCR (invA) and then serotyped using antigenic methods and genome sequencing prediction tools. APC and coliform counts ranged from 1.81 to 5.47 (mean 2.44 ± 0.63) log CFU/g and 0.60 to 5.20 (mean 1.74 ± 0.80) log CFU/g, respectively. Salmonella was recovered from four units in Box 1 and all seven units in Box 2. One of the 10 subsamples was positive in all but four of the positive units; one (Box 1) and three (Box 2) units had two positive subsamples. The level of Salmonella in the two boxes combined was 0.0023 most probable number/g (95% confidence interval [0.0014, 0.0038]). Salmonella Urbana was isolated from three of five positive subsamples in Box 1 and eight of 10 positive subsamples in Box 2. Salmonella Fresno and Vinohrady were unique to single subsamples from Box 1, and Salmonella Nima was isolated from two subsamples from Box 2. Of the four serovars recovered, Salmonella Urbana and Salmonella Vinohrady were in common with outbreak-associated clinical or product isolates. Understanding the distribution and concentration of Salmonella in naturally contaminated cashews provides important information for hazard analysis and risk assessments for soaked and fermented cashew products. |
| first_indexed | 2024-03-12T22:09:22Z |
| format | Article |
| id | doaj.art-bd5d1af89be04d98b9bd66ce34bc8149 |
| institution | Directory Open Access Journal |
| issn | 0362-028X |
| language | English |
| last_indexed | 2024-03-12T22:09:22Z |
| publishDate | 2023-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Food Protection |
| spelling | doaj.art-bd5d1af89be04d98b9bd66ce34bc81492023-07-24T04:10:20ZengElsevierJournal of Food Protection0362-028X2023-08-01868100109Levels and Distribution of Salmonella in Naturally Contaminated CashewsHanna Louvau0Linda J. Harris1Department of Food Science and Technology and University of California, Davis, One Shields Avenue, Davis, CA 95616-8598, USACorresponding author at: Department of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616-8598, USA.; Department of Food Science and Technology and University of California, Davis, One Shields Avenue, Davis, CA 95616-8598, USARaw materials associated with foodborne illness outbreaks are rarely available for evaluation. The levels and distribution of Salmonella were determined in naturally contaminated raw cashews linked to a salmonellosis outbreak associated with a fermented cashew cheese analog. Two unopened 22.7-kg boxes from a single lot of cashew kernel pieces were each divided into seven approximately equal units, 14 in total. Three 10-g subsamples per unit (n = 21) were evaluated for aerobic plate count (APC), coliform counts, and Escherichia coli counts, and 10 50-g subsamples per unit (n = 70) were enriched for the presence of Salmonella. Presumptive Salmonella-positive colonies were confirmed using CHROMagar Salmonella and real-time PCR (invA) and then serotyped using antigenic methods and genome sequencing prediction tools. APC and coliform counts ranged from 1.81 to 5.47 (mean 2.44 ± 0.63) log CFU/g and 0.60 to 5.20 (mean 1.74 ± 0.80) log CFU/g, respectively. Salmonella was recovered from four units in Box 1 and all seven units in Box 2. One of the 10 subsamples was positive in all but four of the positive units; one (Box 1) and three (Box 2) units had two positive subsamples. The level of Salmonella in the two boxes combined was 0.0023 most probable number/g (95% confidence interval [0.0014, 0.0038]). Salmonella Urbana was isolated from three of five positive subsamples in Box 1 and eight of 10 positive subsamples in Box 2. Salmonella Fresno and Vinohrady were unique to single subsamples from Box 1, and Salmonella Nima was isolated from two subsamples from Box 2. Of the four serovars recovered, Salmonella Urbana and Salmonella Vinohrady were in common with outbreak-associated clinical or product isolates. Understanding the distribution and concentration of Salmonella in naturally contaminated cashews provides important information for hazard analysis and risk assessments for soaked and fermented cashew products.http://www.sciencedirect.com/science/article/pii/S0362028X23067819Low moistureMost probable numberOutbreakPathogenPrevalenceTree nuts |
| spellingShingle | Hanna Louvau Linda J. Harris Levels and Distribution of Salmonella in Naturally Contaminated Cashews Journal of Food Protection Low moisture Most probable number Outbreak Pathogen Prevalence Tree nuts |
| title | Levels and Distribution of Salmonella in Naturally Contaminated Cashews |
| title_full | Levels and Distribution of Salmonella in Naturally Contaminated Cashews |
| title_fullStr | Levels and Distribution of Salmonella in Naturally Contaminated Cashews |
| title_full_unstemmed | Levels and Distribution of Salmonella in Naturally Contaminated Cashews |
| title_short | Levels and Distribution of Salmonella in Naturally Contaminated Cashews |
| title_sort | levels and distribution of salmonella in naturally contaminated cashews |
| topic | Low moisture Most probable number Outbreak Pathogen Prevalence Tree nuts |
| url | http://www.sciencedirect.com/science/article/pii/S0362028X23067819 |
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