8 results on '"Thames, Hudson T."'
Search Results
2. Aerotolerance and Multi-Locus Sequence Typing of Campylobacter jejuni Isolated from Commercial Broiler Processing Plants.
- Author
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Pokhrel, Diksha, Thames, Hudson T., Zhang, Li, Dinh, Thu, Schilling, M. Wes, White, Shecoya, Ramachandran, Reshma, and Sukumaran, Anuraj T.
- Subjects
CAMPYLOBACTER jejuni ,POULTRY processing ,GENETIC variation ,FOOD production ,FREEZING - Abstract
Campylobacter jejuni is one of the leading causes of acute diarrhea in the United States. Despite being a microaerophilic pathogen, C. jejuni continues to endure within the domain of food production, especially in poultry processing. Recent research on aerotolerance indicates that close monitoring of this pathogen is necessary. A total of 40 C. jejuni isolates previously obtained from commercial broiler processing plants were analyzed for aerotolerance and genetic diversity. In addition, the effect of aerotolerance and storage time (days) on the survival of C. jejuni on broiler drumsticks at refrigeration (4 °C) and freezing conditions (−20 °C) was also evaluated. Out of 40 isolates, 25 (62.5%) were aero-sensitive (AS), 10 (25%) were intermediately aerotolerant (IAT), and 5 (12.5%) were hyper aerotolerant (HAT). The isolates belonged to four clonal complexes (CCs) and six sequence types, with the majority of isolates assigned to the CC–353 clonal complex. C. jejuni counts were reduced by 0.40 log CFU/g after 7 days at 4 °C and by 1.50 log CFU/g after 14 days at −20 °C, respectively, irrespective of aerotolerance (p < 0.001). At both refrigeration (p < 0.013) and freezing (p < 0.001), HAT showed greater reductions as compared to AS and IAT. These findings suggest that both refrigeration and freezing reduce C. jejuni counts. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Salmonella Biofilm Formation under Fluidic Shear Stress on Different Surface Materials.
- Author
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Thames, Hudson T., Pokhrel, Diksha, Willis, Emma, Rivers, Orion, Dinh, Thu T. N., Zhang, Li, Schilling, Mark W., Ramachandran, Reshma, White, Shecoya, and Sukumaran, Anuraj T.
- Subjects
SHEARING force ,SURFACES (Technology) ,BIOFILMS ,SALMONELLA ,SCANNING electron microscopy ,PLANT surfaces ,GENTIAN violet - Abstract
This study characterized biofilm formation of various Salmonella strains on common processing plant surface materials (stainless steel, concrete, rubber, polyethylene) under static and fluidic shear stress conditions. Surface-coupons were immersed in well-plates containing 1 mL of Salmonella (6 log CFU/mL) and incubated aerobically for 48 h at 37 °C in static or shear stress conditions. Biofilm density was determined using crystal violet assay, and biofilm cells were enumerated by plating on tryptic soy agar plates. Biofilms were visualized using scanning electron microscopy. Data were analyzed by SAS 9.4 at a significance level of 0.05. A surface–incubation condition interaction was observed for biofilm density (p < 0.001). On stainless steel, the OD
600 was higher under shear stress than static incubation; whereas, on polyethylene, the OD600 was higher under static condition. Enumeration revealed surface–incubation condition (p = 0.024) and surface–strain (p < 0.001) interactions. Among all surface–incubation condition combinations, the biofilm cells were highest on polyethylene under fluidic shear stress (6.4 log/coupon; p < 0.001). Biofilms of S. Kentucky on polyethylene had the highest number of cells (7.80 log/coupon) compared to all other strain–surface combinations (p < 0.001). Electron microscopy revealed morphological and extracellular matrix differences between surfaces. Results indicate that Salmonella biofilm formation is influenced by serotype, surface, and fluidic shear stress. [ABSTRACT FROM AUTHOR]- Published
- 2023
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4. Roles of Aerotolerance, Biofilm Formation, and Viable but Non-Culturable State in the Survival of Campylobacter jejuni in Poultry Processing Environments.
- Author
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Pokhrel, Diksha, Thames, Hudson T., Zhang, Li, Dinh, Thu T. N., Schilling, Wes, White, Shecoya B., Ramachandran, Reshma, and Theradiyil Sukumaran, Anuraj
- Subjects
CAMPYLOBACTER jejuni ,POULTRY processing ,BIOFILMS ,POULTRY products ,MEAT ,TIME pressure - Abstract
Campylobacter jejuni is one of the most common causes of foodborne human gastroenteritis in the developed world. This bacterium colonizes in the ceca of chickens, spreads throughout the poultry production chain, and contaminates poultry products. Despite numerous on farm intervention strategies and developments in post-harvest antimicrobial treatments, C. jejuni is frequently detected on broiler meat products. This indicates that C. jejuni is evolving over time to overcome the stresses/interventions that are present throughout poultry production and processing. The development of aerotolerance has been reported to be a major survival strategy used by C. jejuni in high oxygen environments. Recent studies have indicated that C. jejuni can enter a viable but non-culturable (VBNC) state or develop biofilm in response to environmental stressors such as refrigeration and freezing stress and aerobic stress. This review provides an overview of different stressors that C. jejuni are exposed to throughout the poultry production chain and the genotypic and phenotypic survival mechanisms, with special attention to aerotolerance, biofilm formation, and development of the VBNC state. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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- View/download PDF
5. The Prevalence of Salmonella and Campylobacter on Broiler Meat at Different Stages of Commercial Poultry Processing.
- Author
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Thames, Hudson T., Fancher, Courtney A., Colvin, Mary G., McAnally, Mika, Tucker, Emily, Zhang, Li, Kiess, Aaron S., Dinh, Thu T. N., and Sukumaran, Anuraj T.
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SALMONELLA , *POULTRY processing , *CAMPYLOBACTER , *POULTRY processing plants , *MEAT contamination , *FOOD pathogens , *RAW foods - Abstract
Simple Summary: Salmonella and Campylobacter are two of the most common foodborne pathogens isolated from poultry meat. Over the years, a number of advancements have been made in poultry processing to reduce the prevalence of these pathogens, such as the utilization of peracetic acid in various processing steps. However, despite these efforts, Salmonella and Campylobacter continue to persist in retail broiler meat products. In an effort to characterize the efficacy of existing peracetic acid antimicrobial interventions in the industry, we collected broiler meat samples from throughout the processing chain and from different commercial poultry processing plants. Our results suggest that antimicrobial spray cabinets demonstrate little efficacy in reducing the prevalence of these pathogens. However, the utilization of peracetic acid in carcass chilling tanks remains the most effective chemical intervention. An increase in prevalence during second processing and MDM production suggests that cross-contamination still plays a pivotal role in broiler meat contamination at the retail level. In poultry processing, Salmonella and Campylobacter contaminations are major food safety concerns. Peracetic acid (PAA) is an antimicrobial commonly used in commercial poultry processing to reduce pathogen prevalence so as to meet the USDA-FSIS performance standards. The objective of this study was to determine the prevalence of Salmonella and Campylobacter on broiler meat in various steps of commercial poultry processing in plants that use PAA. Post-pick, pre-chill, post-chill, and drumstick chicken samples were collected from three processing plants and mechanically deboned meat (MDM) was collected from two of the three plants. Each plant was sampled thrice, and 10 samples were collected from each processing step during each visit. Among the 420 samples, 79 were contaminated with Salmonella and 155 were contaminated with Campylobacter. Salmonella and Campylobacter contamination on the post-pick samples averaged 32.2%. Significant reductions in Salmonella and Campylobacter were observed in pre-chill to post-chill samples, where the prevalence was reduced from 34% and 64.4% to nondetectable limits and 1.1%, respectively (p < 0.001). Salmonella and Campylobacter remained undetectable on the drumstick samples in all three processing plants. However, the prevalence of Salmonella and Campylobacter on MDM was similar to the post-pick prevalence, which suggests substantial cross-contamination from post-chill to MDM. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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6. Spoilage Bacteria Counts on Broiler Meat at Different Stages of Commercial Poultry Processing Plants That Use Peracetic Acid.
- Author
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Thames, Hudson T., Fancher, Courtney A., Colvin, Mary G., McAnally, Mika, Tucker, Emily, Zhang, Li, Kiess, Aaron S., Dinh, Thu T. N., and Sukumaran, Anuraj T.
- Subjects
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POULTRY processing plants , *PERACETIC acid , *LACTIC acid bacteria , *BROILER chickens , *AEROBIC bacteria , *MEAT packing houses , *COLIFORMS - Abstract
Simple Summary: The presence of spoilage bacteria on broiler meat is known to cause deleterious effects, such as off odors and color, and contributes to a shorter shelf life. While spoilage microbes do not pose a major health concern, the presence of these bacteria results in economic loss that could be mitigated during processing. In order to evaluate the efficacy of antimicrobial interventions on spoilage microbes, we collected broiler meat samples from various stages of commercial poultry processing plants that use different applications and concentrations of peracetic acid. From these results, we conclude that the most effective intervention occurs during carcass chilling. However, the presence of aerobic bacteria and coliforms on broiler meat during second processing suggests cross contamination, which could affect the shelf life of retail chicken parts. In poultry processing, spoilage microbes are persistent microorganisms, which affect the quality of broiler meat. Peracetic acid (PAA) is the most common antimicrobial used by commercial processing plants, which can reduce the prevalence of these microbes. The goal of this study was to determine the concentrations of aerobic bacteria, coliforms, lactic acid bacteria, and Pseudomonas on broiler meat in processing plants that use peracetic acid in various concentrations as the primary antimicrobial. Samples were collected from three processing plants at five processing steps: post-pick (defeathering), pre-chill, post-chill, mechanically deboned meat (MDM), and drumsticks. Samples were rinsed in buffered peptone water for bacteria isolation. Over six log CFU/sample of aerobic plate counts (APC), lactic acid bacteria, and coliforms were detected on post-pick samples. All spoilage bacteria were reduced to nondetectable levels on post-chill samples (p < 0.001). However, the presence of all bacteria on mechanically deboned meat (MDM) samples indicated varying degrees of cross contamination from post-chill and MDM samples. These results suggest PAA effectively reduces spoilage microbes in chilling applications irrespective of differences in PAA concentrations. However, due to the levels of spoilage microbes detected in MDM, it may be worth investigating the potential interventions for this stage of processing. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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7. Increase in temperature facilitates Campylobacter jejuni biofilm formation under both aerobic and microaerobic incubation.
- Author
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Pokhrel, Diksha, Thames, Hudson T., Fugate, Hailey, Dinh, Thu, Schilling, Wes, White, Shecoya, Ramachandran, Reshma, Sukumaran, Anuraj T., and Zhang, Li
- Subjects
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BIOFILMS , *CAMPYLOBACTER jejuni , *POULTRY processing , *STAINLESS steel , *GENTIAN violet , *OPACITY (Optics) - Abstract
The formation of Campylobacter jeuni biofilms on processing surfaces is a significant concern in poultry processing, contributing to food safety risks. This study focused on assessing the biofilm forming capabilities of 12 field isolates of C. jejuni of different aerotolerance categories on stainless steel surfaces, a prevalent material in poultry processing environments. Working cultures of each isolate were prepared to approximately 6 log CFU/mL and incubated on stainless steel coupons under microaerobic or aerobic conditions at room temperature or 42°C for 72 h. Biofilm attached cells were enumerated using direct plating and biofilm density was measured using a crystal violet assay by measuring the optical density (OD 600) a. Data analysis was conducted using the PROC GLIMMIX procedure in SAS 9.4 with a significance level of 0.05. The study revealed a notable interaction between aerotolerance categories and temperature (P < 0.039) impacting the number of biofilms attached C. jejuni cells on stainless steel coupons. All isolates had significantly higher counts when incubated at 42°C compared to room temperature, regardless of oxygen level (P < 0.001). Furthermore, stronger biofilm density was observed at 42°C compared to room temperature, regardless of oxygen level. These findings underscore the influence of temperature on the biofilm forming ability of C. jejuni. The ability of these field isolates to form biofilms under various environmental conditions suggests a heightened potential for surface colonization and increased infection risk in poultry processing facilities. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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8. A Review of Salmonella and Campylobacter in Broiler Meat: Emerging Challenges and Food Safety Measures.
- Author
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Thames, Hudson T. and Theradiyil Sukumaran, Anuraj
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FOOD safety ,CAMPYLOBACTER jejuni ,CAMPYLOBACTER ,SALMONELLA ,ELECTROSTATIC atomization ,BACTERIAL contamination - Abstract
Poultry is one of the largest sources of animal-based protein in the United States. Poultry processing has grown from a small local network of plants to nearly 500 plants nationwide. Two of the most persistent bacteria in poultry processing are Salmonella and Campylobacter. It was not until the introduction of Hazard Analysis and Critical Control Point systems in 1996 that major efforts to reduce bacterial contamination were developed. Traditionally, chlorine has been the industry standard for decontaminating chicken meat. However, antimicrobials such as peracetic acid, cetylpyridinium chloride, and acidified sodium chlorite have replaced chlorine as primary antimicrobials. Despite current interventions, the emergence of stress-tolerant and biofilm-forming Salmonella and Campylobacter is of primary concern. In an effort to offset growing tolerance from microbes, novel techniques such as cold plasma treatment, electrostatic spraying, and bacteriophage-based applications have been investigated as alternatives to conventional treatments, while new chemical antimicrobials such as Amplon and sodium ferrate are investigated as well. This review provides an overview of poultry processing in the United States, major microbes in poultry processing, current interventions, emerging issues, and emerging technologies in antimicrobial treatments. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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