Journal of food protection最新文献

Through deteriorating the quality of shrimp, Vibrio parahaemolyticus and heavy metals have become threatened to food safety. The study was conducted to explore shrimp and their environments for antibiotic resistance genes of V. parahaemolyticus and perform spectrophotometry of shrimp muscles for heavy metals and their human health risk assessment. In total, 130 samples (shrimp, water, and sediment) were aseptically collected from 27 ponds in four areas of Khulna and Satkhira districts where the number of water and sediments were corresponded to the number of ponds and the number of shrimps differed from pond to pond. V. parahaemolyticus were detected by cultural, staining, biochemical, and molecular techniques targeting groEL, tetA, tetB, tetC, and bla_TEM genes. Disc diffusion assay and bivariate analysis were performed for investigating antibiotic resistance profiles of V. parahaemolyticus. Cadmium, chromium, lead, zinc, and iron were measured by AAS (atomic absorption spectrometry) in shrimp. Among 39 isolates (23 from shrimp, 7 from water, 9 from sediment), real-time PCR (polymerase chain reaction) detected 20 of 27 as positive for groEL, 12 of 20 for tetA, 13 for tetB, 12 for tetC, and 1 for bla_TEM. V. parahaemolyticus were highly resistant to tetracycline and ampicillin. Bivariate analysis revealed a significant correlation between the antibiotics. 51.28% isolates were MDR (multidrug resistant), and the MAR (multiple antibiotic resistance) indices ranged from 0.08-0.6. The highest average concentration for Cd was in Debhata, Pb in Dumuria, Cr in Kaliganj, Zn and Fe in Satkhira Sadar. THQ (target hazard quotients) of >1 for Fe in all sampling sites showed higher level of HI (hazard index). No determined TR (target cancer risk) value exceeded the recommended value (<10^-4). The study emphasizes the significance of adopting extensive surveillance and monitoring of a large number of shrimp farms for effective antibiotic management and sustainable shrimp production.

Preharvest interventions can play an important role in reducing Salmonella prevalence and levels entering poultry slaughter and processing establishments. Currently, there is not a systematic literature review of preharvest interventions that control Salmonella in poultry in the United States (U.S.). The objective herein was to synthesize literature published on the effectiveness of preharvest interventions in U.S. poultry production. Utilizing the Methodological Expectations of Cochrane Intervention Reviews guidelines, a literature search was conducted. Experimental studies published from 1995 to 2022 assessing preharvest interventions to control Salmonella in U.S. poultry farms were included in the review if they reported prevalence or levels of Salmonella. Data were extracted from each article by two reviewers. Descriptive statistics were used to summarize key study parameters, (e.g., study design, study location, poultry type, Salmonella serotypes, type of intervention) and effectiveness of intervention. A total of 12,403 publications were identified, and 234 publications were included in the final review. The most evaluated interventions were feed/water additives (51.50%), competitive exclusion culture (10.30%), vaccination/immunization (7.88%), chemical treatments/compounds (5.45%) and probiotic culture (4.85%). Most studies focused on broiler chicken (78.20%) compared to turkey, and investigated Salmonella Typhimurium (37.60%), S. Enteritidis (29.10%), and S. Heidelberg (8.48%). Overall, the effectiveness of evaluated interventions varied, though one should consider differences may be due to study design, sample sizes and duration of interventions. This review improves our understanding of the breadth of preharvest interventions and their effectiveness against Salmonella in poultry and can be used to inform food safety policies and practices around poultry to protect public health.

The aim of this study is to measure the UV-C inactivation kinetics and determine the fluences required for incremental inactivation of Alicyclobacillus acidoterrestris (AAT). Spores from five strains of AAT (ATCC 49025, DSM 2498, VF, SAC, and WAC) were suspended in clear phosphate buffered saline (PBS) and individually treated with UV-C doses up to 100 mJ/cm². A collimated beam device emitting UV-C at 254 nm (from a monochromatic low-pressure mercury lamp [LPM]) and at 268 nm (from UV light-emitting diodes [UV-LEDs]) was used for UV treatments. The log reduction from each treatment was plotted against the UV-C fluence. Curve fitting using the GInaFiT tool for Excel was attempted using both linear and non-linear regression models. The goodness-of-fit and model performances, assessed using Akaike's Information Criterion and Bayesian Information Criterion, revealed that the Weibull model provided a better fit for the inactivation data and was thus used to determine UV-C doses required for 1-log inactivation and incremental log inactivation. Similar AAT spore inactivation efficacy was observed at both 254 and 268 nm. A UV-C dose of 100 mJ/cm² at 254 nm inactivated >4-log CFU/mL, while at 268 nm, a 3.7- to 5.08-log CFU/mL reduction was observed for AAT strains ATCC 49025, DSM 2498, WAC, and VF. Among the five strains of AAT tested, spores of WAC demonstrated greater resistance, requiring UV-C doses of 2.76 mJ/cm² and 100 mJ/cm² for 1-log (D₁₀-value) and 4-log inactivation at 254 nm, and 5.89 mJ/cm² and >100 mJ/cm² at 268 nm. In contrast, spores of SAC showed greater sensitivity, with UV-C doses of 1.87 mJ/cm² and 47.92 mJ/cm² required for 1-log and 4-log inactivation at 254 nm, and 6.20 mJ/cm² and 44.61 mJ/cm² at 268 nm. This study lays the foundation for designing successful UV-based non-thermal pasteurization system.

Food contact surfaces, including harvest bags, are potential vectors for cross-contamination in produce operations, yet recommendations for their sanitation are limited. This study evaluated the efficacy of wet- and dry-based sanitizers in reducing Listeria monocytogenes and Salmonella on two harvest bag materials, canvas, and Cordura®. Coupons (25cm²) were inoculated with 5-strain cocktails of L. monocytogenes or Salmonella (∼7 log CFU/coupon) before treatment. Treatments included chlorine (200 ppm; pH 7), peroxyacetic acid (PAA; 200 ppm), isopropyl alcohol with quaternary ammonium compounds (IPAQuats; ready-to-use), steam, and water. Sanitizers were applied according to the manufacturer's instructions for a 1-minute contact time. After treatment, pathogen concentrations were enumerated on selective (Modified Oxford, Xylose Lysine Deoxycholate) and non-selective (Tryptic Soy Agar) media. Duplicate experiments were conducted with five replicates per treatment (n=10) and pathogen reductions were evaluated using log-linear mixed-effects models. IPAQuats observed the highest reductions with L. monocytogenes reductions of 5.16±0.93 log CFU/coupon and 6.01±0.49 log CFU/coupon, and Salmonella reductions of 4.61 ± 1.03 log CFU/coupon and 5.90 ± 0.57 log CFU/coupon on canvas and Cordura®, respectively. PAA resulted in L. monocytogenes reductions of 2.63±0.56 and 3.92±0.81 log CFU/coupon and Salmonella reductions of 3.68±0.79 and 3.21±1.14 log CFU/coupon on canvas and Cordura®, respectively. Chlorine and steam were less effective with reductions of <3 log CFU/coupon for both pathogens and materials. While no difference in L. monocytogenes reduction was observed between materials by treatment, Salmonella reductions on Cordura® were significantly higher than reductions on canvas after treatments with IPAQuats (1.62 log CFU/coupon; 95% CI=1.19, 2.05) and steam (0.84 log CFU/coupon; 95% CI=0.42, 1.28). Results provide recommendations for produce growers on effective sanitation of harvest bags.

Harvest bags, if not properly cleaned and sanitized, can serve as sources of microbial contamination, making it vital to understand pathogen survival on these surfaces to inform sanitation best practices. The objective was to assess the survival of generic Escherichia coli, Listeria monocytogenes, and Salmonella enterica on harvest bag materials: 100% canvas, nylon, and Cordura. Coupons from each material were inoculated with rifampicin-resistant strains of E. coli or rifampicin-resistant 5-strain cocktails of L. monocytogenes or S. enterica at ca. 7.3±0.1 log CFU/coupon. Coupons were air-dried until inoculum was visibly dry and held at 22°C under different relative humidity (RH): 30 or 80% RH for E. coli (90d) and 55% RH for L. monocytogenes and S. enterica (21d). E. coli concentration was enumerated at 12 time-points: 0, 1.5, 4, and 8 h, and 1, 2, 3, 7, 14, 30, 60, and 90 d post-inoculation. L. monocytogenes and S. enterica levels were enumerated at 10 time-points: 0, 1, 4, and 8 h, and 1, 2, 3, 7, 14, and 21 d. Coupons were massaged for 60s with 20 mL of 0.1% peptone and plated in duplicate on selective and non-selective media in triplicate experiments with triplicate replicates (n=9). Models were fitted to describe bacterial die-off in log CFU/coupon over time. E. coli exhibited a triphasic die-off with a faster rate of die-off on nylon surfaces. S. enterica demonstrated greater die-off on Cordura compared to canvas, and L. monocytogenes followed a biphasic die-off, with no significant difference in survival across the materials. Findings indicate E. coli survival was influenced by RH, time, and material, with the fastest die-off on nylon materials. S. enterica die-off was influenced by material and time with a faster die-off on Cordura. L. monocytogenes exhibited similar die-off on canvas and Cordura. Sanitization of harvest bags are recommended to reduce contamination risks as pathogen survival can be influenced by bag material and environmental conditions.

Unpasteurised dairy products carry an inherent risk of being contaminated with STEC and/or other zoonotic gastrointestinal pathogens. In November 2023, a genetically linked and geographically dispersed outbreak of 36 cases of Shiga toxin-producing Escherichia coli (STEC) O145:H28 was detected by the foodborne gastrointestinal pathogens surveillance systems at the UK Health Security Agency, using whole genome sequencing. Reported symptoms included diarrhoea (81%), bloody diarrhoea (65%), vomiting (84%) and 47% of cases were admitted to hospital. A review of the completed enhanced surveillance questionnaires (n=29) revealed 18 cases reporting travelling first class on trains operated by the same company prior to onset of symptoms, of which 16/18 consumed the same meal which included an unpasteurised cheese. Microbiological testing of the cheese products did not detect the outbreak strain, however STEC O145:H28 was detected in two bovine faecal samples collected at the dairy farm where the unpasteurised cheese was produced. Analysis of the genome sequencing data confirmed that the 36 human STEC O145 isolates and the two bovine STEC O145 isolates fell within the same 5 SNP single linkage cluster. These findings indicated that the cattle were the likely source of the human infections, via the consumption of contaminated unpasteurised cheese. The food business operator voluntarily recalled the implicated product from sale. Vulnerable groups, such as those who are very young, elderly, pregnant or immunocompromised, should avoid consuming raw drinking milk and cheeses. Due to advances in clinical molecular diagnostics and enhanced epidemiological surveillance, notifications of foodborne outbreaks of STEC other than serogroups O157 are increasing in the UK. Further improvements in microbiological methods for detecting STEC on the farm and in food, are essential for the pre-sale identification of contaminated food items and to reduce the risks to public health.