{"doi":"10.1016/j.jfp.2025.100629","title":"Prevalence and Levels of Shiga Toxin–producing Escherichia coli and Salmonella in California Raw Almond Kernels From the 2021 Harvest Compared With Data From Harvests Between 2001 and 2013","abstract":"The prevalence and levels of pathogens in foods are critical inputs for quantitative microbial risk assessment. This study aimed to determine the prevalence, levels, and distribution of Escherichia coli O157:H7, non-O157 Shiga toxin-producing E. coli (STEC), and Salmonella on raw almond kernels from the 2021 California harvest, and to compare the results with data from 2001 to 2013. During the 2021 harvest, 1-2 kg samples were collected at processing facilities from 601 incoming single-variety almond lots representing 15 varieties. Each lot was tested for the presence of E. coli O157:H7 and STEC using 375-g subsamples and for Salmonella using 100-g subsamples. Aerobic plate count (APC) and levels of coliforms, Enterobacteriaceae, yeasts, and molds were determined for a subset of positive and negative lots. Salmonella levels in positive lots were estimated using a modified three-tube most-probable-number (MPN) method with additional 25- and 50-g subsamples processed through sample depletion. A subset of Salmonella-negative lots was also retested using multiple 100-g subsample enrichments. None of the 601 lots was positive for either E. coli O157:H7 or STEC. Salmonella was isolated from 18 lots (3.0% [95% CI, 1.8-4.7%]), a higher prevalence than the 9-year average from earlier surveys (0.98% [95% CI, 0.83-1.2%]). Estimated Salmonella levels in 2021 ranged from 0.0016 to 0.011 MPN/g (mean 0.0034 ± 0.0023 MPN/g), consistent with 2001-2013 levels (mean 0.012 ± 0.017 MPN/g; range, 0.00020-0.15 MPN/g). Whole-genome sequencing of 2021 isolates identified Salmonella enterica subspecies arizonae, diarizonae, and enterica, including nine Salmonella enterica subspecies enterica serovars. No significant differences (P > 0.05) in APC or levels of yeasts, molds, coliforms, or Enterobacteriaceae were observed between Salmonella-positive and -negative lots in 2021, consistent with findings from earlier surveys. Salmonella detection was not associated with almond variety.","journal":"Journal of Food Protection","year":2025,"id":536756,"datarank":0.10397207708399181,"base_score":0.6931471805599453,"endowment":0.6931471805599453,"self_citation_contribution":0.10397207708399181,"citation_network_contribution":0.0,"self_endowment_contribution":0.10397207708399181,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9499,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1422077,"name":"Vanessa Lieberman","orcid":"0000-0002-7531-9126","position":1,"is_corresponding":false},{"id":1422595,"name":"Sheryl Long","orcid":null,"position":2,"is_corresponding":false},{"id":1119138,"name":"Anne-Laure Moyne","orcid":"0000-0002-0211-4269","position":3,"is_corresponding":false},{"id":1102350,"name":"Linda J. Harris","orcid":"0000-0002-1911-752X","position":0,"is_corresponding":true}],"reference_count":36,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:52:09.056872Z","pmid":"41016511","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}