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Javan GT, Singh K, Finley SJ, Green RL, Sen CK. Complexity of human death: its physiological, transcriptomic, and microbiological implications. Front Microbiol 2024; 14:1345633. [PMID: 38282739 PMCID: PMC10822681 DOI: 10.3389/fmicb.2023.1345633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 12/28/2023] [Indexed: 01/30/2024] Open
Abstract
Human death is a complex, time-governed phenomenon that leads to the irreversible cessation of all bodily functions. Recent molecular and genetic studies have revealed remarkable experimental evidence of genetically programmed cellular death characterized by several physiological processes; however, the basic physiological function that occurs during the immediate postmortem period remains inadequately described. There is a paucity of knowledge connecting necrotic pathologies occurring in human organ tissues to complete functional loss of the human organism. Cells, tissues, organs, and organ systems show a range of differential resilience and endurance responses that occur during organismal death. Intriguingly, a persistent ambiguity in the study of postmortem physiological systems is the determination of the trajectory of a complex multicellular human body, far from life-sustaining homeostasis, following the gradual or sudden expiry of its regulatory systems. Recent groundbreaking investigations have resulted in a paradigm shift in understanding the cell biology and physiology of death. Two significant findings are that (i) most cells in the human body are microbial, and (ii) microbial cell abundance significantly increases after death. By addressing the physiological as well as the microbiological aspects of death, future investigations are poised to reveal innovative insights into the enigmatic biological activities associated with death and human decomposition. Understanding the elaborate crosstalk of abiotic and biotic factors in the context of death has implications for scientific discoveries important to informing translational knowledge regarding the transition from living to the non-living. There are important and practical needs for a transformative reestablishment of accepted models of biological death (i.e., artificial intelligence, AI) for more precise determinations of when the regulatory mechanisms for homeostasis of a living individual have ceased. In this review, we summarize mechanisms of physiological, genetic, and microbiological processes that define the biological changes and pathways associated with human organismal death and decomposition.
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Affiliation(s)
- Gulnaz T. Javan
- Department of Physical and Forensic Sciences, Alabama State University, Montgomery, AL, United States
| | - Kanhaiya Singh
- Department of Surgery, School of Medicine, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sheree J. Finley
- Department of Physical and Forensic Sciences, Alabama State University, Montgomery, AL, United States
| | - Robert L. Green
- Department of Physical and Forensic Sciences, Alabama State University, Montgomery, AL, United States
| | - Chandan K. Sen
- Department of Surgery, School of Medicine, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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Esmaeilnejad-Ahranjani P, Majidi B, Paradise A, Hasanzadeh M. Optimization and scale-up of Clostridium perfringens type D culture and epsilon-toxin production: Effects of stirring, glucose and pH adjustment. Toxicon 2023; 234:107302. [PMID: 37769818 DOI: 10.1016/j.toxicon.2023.107302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 09/11/2023] [Accepted: 09/26/2023] [Indexed: 10/03/2023]
Abstract
The effects of some main bacteria culture parameters including mixing rate, glucose (GC) concentration, steps of GC addition, and steps of pH adjustment on both C. perfringens bacteria growth and its epsilon toxin production in a bench-scale 20-L glass carboy were investigated. The optimized mixing rate of 300 rpm, GC concentration of 4 g L-1, and 3-step addition of GC resulted in the bacteria and toxin concentrations of 0.16 g L-1 and 330 ng mL-1, respectively. Also, the induction of a pH shock at the reaction time of 180 min led to the remarkable enhancement of toxin production (367 ng mL-1). Upon applying both optimized conditions for GC addition and pH adjustment, the high toxin concentration of 433 ng mL-1 was obtained. Using the constant mixing rate technique, the process was scaled up to a 1500-L industrial bioreactor, where its performance was close to the bench-scale bioreactor (i.e., toxin concentration of 419 ng mL-1). The results revealed the reliability of this method to economically improve and scale up the bacteria culture process, which can be further used for other microbial fermentations.
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Affiliation(s)
- Parvaneh Esmaeilnejad-Ahranjani
- Department of Anaerobic Bacterial Vaccine Research and Production, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), P.O. Box: 31975/148, Karaj, Iran; Department for Materials Synthesis, Jožef Stefan Institute, 1000, Ljubljana, Slovenia.
| | - Behjat Majidi
- Razi Vaccine and Serum Research Institute, Mashhad Branch, Agricultural Research, Education and Extension Organization (AREEO), Mashhad, Iran
| | - Alireza Paradise
- Department of Anaerobic Bacterial Vaccine Research and Production, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), P.O. Box: 31975/148, Karaj, Iran
| | - Mona Hasanzadeh
- Department of Anaerobic Bacterial Vaccine Research and Production, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), P.O. Box: 31975/148, Karaj, Iran
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Abstract
Clostridium perfringens, a prevalent Gram-positive bacterium, causes necrotic diseases associated with abundant life loss and economic burdens of billions of USD. The mechanism of C. perfringens-induced necrotic diseases remains largely unknown, in part, because of the lack of effective animal models and the presence of a large array of exotoxins and diverse disease manifestations from the skin and deep tissues to the gastrointestinal tract. In the light of the advancement of medical and veterinary research, a large body of knowledge is accumulating on the factors influencing C. perfringens-induced necrotic disease onset, development, and outcomes. Here, we present an overview of the key virulence factors of C. perfringens exotoxins. Subsequently, we focus on comprehensively reviewing C. perfringens-induced necrotic diseases such as myonecrosis, acute watery diarrhea, enteritis necroticans, preterm infant necrotizing enterocolitis, and chicken necrotic enteritis. We then review the current understanding on the mechanisms of myonecrosis and enteritis in relation to the immune system and intestinal microbiome. Based on these discussions, we then review current preventions and treatments of the necrotic diseases and propose potential new intervention options. The purpose of this review is to provide an updated and comprehensive knowledge on the role of the host–microbe interaction to develop new interventions against C. perfringens-induced necrotic diseases.
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El Kadri H, Alaizoki A, Celen T, Smith M, Onyeaka H. The effect of low-temperature long-time (LTLT) cooking on survival of potentially pathogenic Clostridium perfringens in beef. Int J Food Microbiol 2020; 320:108540. [PMID: 32044624 DOI: 10.1016/j.ijfoodmicro.2020.108540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 10/10/2019] [Accepted: 01/26/2020] [Indexed: 02/02/2023]
Abstract
Low-temperature long-time (LTLT) cooking may lead to risk of potential survival of pathogenic bacteria such as Clostridium perfringens in cooked meat. In this study, the effect of LTLT cooking on C. perfringens was investigated at temperatures commonly used by caterers. Brain heart infusion broth (BHIB) and meat cubes in pouches (vacuumed or non-vacuumed) were inoculated with C. perfringens (NCTC 8238) and heated at temperatures of 48 °C, 53 °C, 55 °C, 60 °C and 70 °C. The viability of C. perfringens in BHIB and meat was monitored using plate counting and the D-value of each thermal treatment was determined. The recovery of C. perfringens after thermal treatment was assessed using optical density measurements. Flow cytometry analysis was used to assess the physiological status (death/injury) of C. perfringens cells in BHIB. The results showed that the required log reduction (6-log) of C. perfringens can be achieved at 55 °C but not at 48 °C or 53 °C. The D-values at all temperatures were higher in meat compared to BHIB while the D-value at 55 °C was higher in non-vacuum compared to vacuum sealed meat. C. perfringens cells were able to recover and grow to pathogenic levels when thermal treatment was unable to achieve the required 6-log reduction. In BHIB, percentage of dead cells increased gradually at 48 °C, 53 °C and 55 °C while an immediate increase (>95%) was observed at 60 °C and 70 °C. These results are important to food safety authorities allowing to set the time-temperature combinations to be used in LTLT cooking to obtain safe meat.
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Affiliation(s)
- Hani El Kadri
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Alaa Alaizoki
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Teyfik Celen
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Madeleine Smith
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Helen Onyeaka
- School of Chemical Engineering, University of Birmingham, B15 2TT Birmingham, United Kingdom.
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Lee CA, Labbé R. Distribution of Enterotoxin- and Epsilon-Positive Clostridium perfringens Spores in U.S. Retail Spices. J Food Prot 2018; 81:394-399. [PMID: 29420063 DOI: 10.4315/0362-028x.jfp-17-352] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The role of spices as vehicles of foodborne illness prompted an examination of bacterial spores in these products. Here, we report on the levels and characteristics of spores of Clostridium perfringens associated with 247 U.S. retail spices. Forty-three confirmed isolates from 17% of samples were obtained, present at levels ranging from 3.6 to 2,400/g. Twenty-seven (63%) of C. perfringens isolates were positive for the enterotoxin gene ( cpe). Seven random spice isolates produced enterotoxin at levels of between 4 and 16 ng/mL, compared with three outbreak (control) strains that each produced enterotoxin levels of >1,024 ng/mL. D95°C levels (1.0 to 3.3 min) of spores of four randomly selected spice isolates suggests a plasmid-localized cpe, while one had D95°C (>45 min) consistent with chromosomally located cpe. Five of the 43 isolates possessed the epsilon toxin gene ( etx, as well as cpe). Foods could easily become contaminated with spores of cpe-positive C. perfringens by the addition of spices. Because of its spore-forming ability, its rapid generation times at elevated temperatures, improper heating, cooling, and holding conditions could lead to elevated levels of C. perfringens in foods, a requirement for its implication in foodborne outbreaks.
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Affiliation(s)
- Chi-An Lee
- Department of Food Science, 100 Holdsworth Way, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - Ronald Labbé
- Department of Food Science, 100 Holdsworth Way, University of Massachusetts, Amherst, Massachusetts 01003, USA
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Javan GT, Finley SJ, Smith T, Miller J, Wilkinson JE. Cadaver Thanatomicrobiome Signatures: The Ubiquitous Nature of Clostridium Species in Human Decomposition. Front Microbiol 2017; 8:2096. [PMID: 29163394 PMCID: PMC5670113 DOI: 10.3389/fmicb.2017.02096] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/12/2017] [Indexed: 01/21/2023] Open
Abstract
Human thanatomicrobiome studies have established that an abundant number of putrefactive bacteria within internal organs of decaying bodies are obligate anaerobes, Clostridium spp. These microorganisms have been implicated as etiological agents in potentially life-threatening infections; notwithstanding, the scale and trajectory of these microbes after death have not been elucidated. We performed phylogenetic surveys of thanatomicrobiome signatures of cadavers' internal organs to compare the microbial diversity between the 16S rRNA gene V4 hypervariable region and V3-4 conjoined regions from livers and spleens of 45 cadavers undergoing forensic microbiological studies. Phylogenetic analyses of 16S rRNA gene sequences revealed that the V4 region had a significantly higher mean Chao1 richness within the total microbiome data. Permutational multivariate analysis of variance statistical tests, based on unweighted UniFrac distances, demonstrated that taxa compositions were significantly different between V4 and V3-4 hypervariable regions (p < 0.001). Of note, we present the first study, using the largest cohort of criminal cases to date, that two hypervariable regions show discriminatory power for human postmortem microbial diversity. In conclusion, here we propose the impact of hypervariable region selection for the 16S rRNA gene in differentiating thanatomicrobiomic profiles to provide empirical data to explain a unique concept, the Postmortem Clostridium Effect.
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Affiliation(s)
- Gulnaz T. Javan
- Forensic Science Program, Physical Sciences Department, Alabama State University, Montgomery, AL, United States
| | - Sheree J. Finley
- Physical Sciences Department, Alabama State University, Montgomery, AL, United States
| | - Tasia Smith
- Forensic Science Program, Physical Sciences Department, Alabama State University, Montgomery, AL, United States
| | - Joselyn Miller
- Forensic Science Program, Physical Sciences Department, Alabama State University, Montgomery, AL, United States
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Predicting outgrowth and inactivation of Clostridium perfringens in meat products during low temperature long time heat treatment. Int J Food Microbiol 2016; 230:45-57. [DOI: 10.1016/j.ijfoodmicro.2016.03.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 12/23/2015] [Accepted: 03/20/2016] [Indexed: 11/18/2022]
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Mohr TB, Juneja VK, Thippareddi HH, Schaffner DW, Bronstein PA, Silverman M, Cook LV. Assessing the Performance of Clostridium perfringens Cooling Models for Cooked, Uncured Meat and Poultry Products. J Food Prot 2015; 78:1512-26. [PMID: 26219365 DOI: 10.4315/0362-028x.jfp-15-015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Heat-resistant spores of Clostridium perfringens may germinate and multiply in cooked meat and poultry products when the rate and extent of cooling does not occur in a timely manner. Therefore, six cooling models (PMP 7.0 broth model; PMIP uncured beef, chicken, and pork models; Smith-Schaffner version 3; and UK IFR ComBase Perfringens Predictor) were evaluated for relative performance in predicting growth of C. perfringens under dynamic temperature conditions encountered during cooling of cooked, uncured meat and poultry products. The predicted growth responses from the models were extensively compared with those observed in food. Data from 188 time-temperature cooling profiles (176 for single-rate exponential cooling and 12 for dual-rate exponential cooling) were collected from 17 independent sources (16 peer-reviewed publications and one report) for model evaluation. Data were obtained for a variety of cooked products, including meat and poultry slurries, ground meat and poultry products with and without added ingredients (e.g., potato starch, sodium triphosphate, and potassium tetrapyrophosphate), and processed products such as ham and roast beef. Performance of the models was evaluated using three sets of criteria, and accuracy was defined within a 1- to 2-log range. The percentages of accurate, fail-safe, or fail-dangerous predictions for each cooling model differed depending on which criterion was used to evaluate the data set. Nevertheless, the combined percentages of accurate and fail-safe predictions based on the three performance criteria were 34.66 to 42.61% for the PMP 7.0 beef broth model, 100% for the PMIP cooling models for uncured beef, uncured pork and uncured chicken, 80.11 to 93.18% for the Smith-Schaffner cooling model, and 74.43 to 85.23% for the UK IFR ComBase Perfringens Predictor model during single-rate exponential chilling. Except for the PMP 7.0 broth model, the other five cooling models (PMIP, Smith-Schaffner, and UK IFR ComBase) are useful and reliable tools that food processors and regulatory agencies can use to evaluate the safety of cooked or heat-treated uncured meat and poultry products exposed to cooling deviations or to develop customized cooling schedules.
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Affiliation(s)
- T B Mohr
- U.S. Department of Agriculture, Food Safety and Inspection Service, Office of Public Health Science, Science Staff, 530 Center Street N.E., Suite 401, Salem, Oregon 97301, USA.
| | - V K Juneja
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA
| | - H H Thippareddi
- Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA
| | - D W Schaffner
- Department of Food Science, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey 08901, USA
| | - P A Bronstein
- U.S. Department of Agriculture, Food Safety and Inspection Service, Office of Public Health Science, Science Staff, Patriots Plaza III, Suite 9-225B, Washington, D.C. 20250, USA
| | - M Silverman
- U.S. Department of Agriculture, Food Safety and Inspection Service, Office of Policy and Program Development, Risk, Innovations, and Management Division, Patriots Plaza III, Suite 8-124A, Washington, D.C. 20250, USA
| | - L V Cook
- SafetyTaste Solutions LLC, Burke, Virginia 22015, USA
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Jaloustre S, Cornu M, Morelli E, Noël V, Delignette-Muller M. Bayesian modeling of Clostridium perfringens growth in beef-in-sauce products. Food Microbiol 2011; 28:311-20. [DOI: 10.1016/j.fm.2010.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 03/29/2010] [Accepted: 04/01/2010] [Indexed: 11/29/2022]
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Juneja VK, Porto-Fett ACS, Gartner K, Tufft L, Luchansky JB. Potential for growth of Clostridium perfringens from spores in pork scrapple during cooling. Foodborne Pathog Dis 2010; 7:153-7. [PMID: 19785539 DOI: 10.1089/fpd.2009.0405] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We conducted stabilization studies to determine the ability of Clostridium perfringens spores to germinate and grow during exponential cooling of a commercial formulation of pork scrapple. Scrapple was inoculated with a mixture of three strains of C. perfringens spores (NTCC 8238, NCTC 8239, and ATCC 10288), vacuum packaged, and reheated (20 min/93.3 degrees C) in a circulating water bath. The cooked samples were cooled (30 s) in an ice bath before being transferred to a programmable water bath to cool through the temperature range of 54.4 degrees C to 7.2 degrees C in 12, 14, or 21 h to simulate deviations from the required cooling time of 6.5 h. After cooling, the samples, in duplicate, were analyzed to determine if growth from spores had occurred. The samples were plated onto tryptose-sulfite-cycloserine agar and incubated anaerobically at 37 degrees C for 48 h before counting the colonies. Minimal growth (less than 1.0 log) was observed during a 12- or 14 h cooling period. However, when the time to achieve 7.2 degrees C was extended to 21 h, C. perfringens spores germinated and grew from an inoculum of approximately 3.0 log(10) to approximately 7.8 log(10) CFU/g. Thus, scrapple must be cooled after cooking to 7.2 degrees C within 6.5 h, but for no more than 14 h, to prevent a food safety hazard from outgrowth of C. perfringens spores during cooling.
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PAREDES-SABJA DANIEL, TORRES JANTONIO. MODELING OF THE GERMINATION OF SPORES FROMCLOSTRIDIUM PERFRINGENSFOOD POISONING ISOLATES. J FOOD PROCESS ENG 2010. [DOI: 10.1111/j.1745-4530.2008.00340.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Juneja VK, Marks H, Thippareddi H. Predictive model for growth of Clostridium perfringens during cooling of cooked ground chicken. INNOV FOOD SCI EMERG 2009. [DOI: 10.1016/j.ifset.2008.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Modelling the growth of Clostridium perfringens during the cooling of bulk meat. Int J Food Microbiol 2008; 128:41-50. [DOI: 10.1016/j.ijfoodmicro.2008.07.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 06/13/2008] [Accepted: 07/15/2008] [Indexed: 11/17/2022]
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Predictive model for growth of Clostridium perfringens during cooling of cooked uncured beef. Food Microbiol 2008; 25:42-55. [DOI: 10.1016/j.fm.2007.08.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 08/21/2007] [Accepted: 08/29/2007] [Indexed: 11/24/2022]
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Sánchez-Plata MX, Amézquita A, Blankenship E, Burson DE, Juneja V, Thippareddi H. Predictive model for Clostridium perfringens growth in roast beef during cooling and inhibition of spore germination and outgrowth by organic acid salts. J Food Prot 2005; 68:2594-605. [PMID: 16355831 DOI: 10.4315/0362-028x-68.12.2594] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Spores of foodborne pathogens can survive traditional thermal processing schedules used in the manufacturing of processed meat products. Heat-activated spores can germinate and grow to hazardous levels when these products are improperly chilled. Germination and outgrowth of Clostridium perfringens spores in roast beef during chilling was studied following simulated cooling schedules normally used in the processed-meat industry. Inhibitory effects of organic acid salts on germination and outgrowth of C. perfringens spores during chilling and the survival of vegetative cells and spores under abusive refrigerated storage was also evaluated. Beef top rounds were formulated to contain a marinade (finished product concentrations: 1% salt, 0.2% potassium tetrapyrophosphate, and 0.2% starch) and then ground and mixed with antimicrobials (sodium lactate and sodium lactate plus 2.5% sodium diacetate and buffered sodium citrate and buffered sodium citrate plus 1.3% sodium diacetate). The ground product was inoculated with a three-strain cocktail of C. perfringens spores (NCTC 8238, NCTC 8239, and ATCC 10388), mixed, vacuum packaged, heat shocked for 20 min at 75 degrees C, and chilled exponentially from 54.5 to 7.2 degrees C in 9, 12, 15, 18, or 21 h. C. perfringens populations (total and spore) were enumerated after heat shock, during chilling, and during storage for up to 60 days at 10 degrees C using tryptose-sulfite-cycloserine agar. C. perfringens spores were able to germinate and grow in roast beef (control, without any antimicrobials) from an initial population of ca. 3.1 log CFU/g by 2.00, 3.44, 4.04, 4.86, and 5.72 log CFU/g after 9, 12, 15, 18, and 21 h of exponential chilling. A predictive model was developed to describe sigmoidal C. perfringens growth curves during cooling of roast beef from 54.5 to 7.2 degrees C within 9, 12, 15, 18, and 21 h. Addition of antimicrobials prevented germination and outgrowth of C. perfringens regardless of the chill times. C. perfringens spores could be recovered from samples containing organic acid salts that were stored up to 60 days at 10 degrees C. Extension of chilling time to > or =9 h resulted in >1 log CFU/g growth of C. perfringens under anaerobic conditions in roast beef. Organic acid salts inhibited outgrowth of C. perfringens spores during chilling of roast beef when extended chill rates were followed. Although C. perfringens spore germination is inhibited by the antimicrobials, this inhibition may represent a hazard when such products are incorporated into new products, such as soups and chili, that do not contain these antimicrobials, thus allowing spore germination and outgrowth under conditions of temperature abuse.
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Affiliation(s)
- Marcos X Sánchez-Plata
- Department of Food Science and Technology, University of Nebraska, Lincoln, Nebraska, USA
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Amézquita A, Weller CL, Wang L, Thippareddi H, Burson DE. Development of an integrated model for heat transfer and dynamic growth of Clostridium perfringens during the cooling of cooked boneless ham. Int J Food Microbiol 2005; 101:123-44. [PMID: 15862875 DOI: 10.1016/j.ijfoodmicro.2004.10.041] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Revised: 09/21/2004] [Accepted: 10/13/2004] [Indexed: 11/23/2022]
Abstract
Numerous small meat processors in the United States have difficulties complying with the stabilization performance standards for preventing growth of Clostridium perfringens by 1 log10 cycle during cooling of ready-to-eat (RTE) products. These standards were established by the Food Safety and Inspection Service (FSIS) of the US Department of Agriculture in 1999. In recent years, several attempts have been made to develop predictive models for growth of C. perfringens within the range of cooling temperatures included in the FSIS standards. Those studies mainly focused on microbiological aspects, using hypothesized cooling rates. Conversely, studies dealing with heat transfer models to predict cooling rates in meat products do not address microbial growth. Integration of heat transfer relationships with C. perfringens growth relationships during cooling of meat products has been very limited. Therefore, a computer simulation scheme was developed to analyze heat transfer phenomena and temperature-dependent C. perfringens growth during cooling of cooked boneless cured ham. The temperature history of ham was predicted using a finite element heat diffusion model. Validation of heat transfer predictions used experimental data collected in commercial meat-processing facilities. For C. perfringens growth, a dynamic model was developed using Baranyi's nonautonomous differential equation. The bacterium's growth model was integrated into the computer program using predicted temperature histories as input values. For cooling cooked hams from 66.6 degrees C to 4.4 degrees C using forced air, the maximum deviation between predicted and experimental core temperature data was 2.54 degrees C. Predicted C. perfringens growth curves obtained from dynamic modeling showed good agreement with validated results for three different cooling scenarios. Mean absolute values of relative errors were below 6%, and deviations between predicted and experimental cell counts were within 0.37 log10 CFU/g. For a cooling process which was in exact compliance with the FSIS stabilization performance standards, a mean net growth of 1.37 log10 CFU/g was predicted. This study introduced the combination of engineering modeling and microbiological modeling as a useful quantitative tool for general food safety applications, such as risk assessment and hazard analysis and critical control points (HACCP) plans.
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Affiliation(s)
- A Amézquita
- Department of Biological Systems Engineering, University of Nebraska, Lincoln, Nebraska 68583-0726, USA
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Smith-Simpson S, Schaffner DW. Development of a model to predict growth of Clostridium perfringens in cooked beef during cooling. J Food Prot 2005; 68:336-41. [PMID: 15726978 DOI: 10.4315/0362-028x-68.2.336] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The objective of this work was to develop a new model to predict the growth of Clostridium perfringens in cooked meat during cooling. All data were collected under changing temperature conditions. Individual growth curves were fit using DMFit. Germination outgrowth and lag (GOL) time was modeled versus temperature at the end of GOL using conservative assumptions. Each growth curve was used to estimate a series of exponential growth rates at a series of temperatures. The squareroot model was used to describe the relationship between the square root of the average exponential growth rate and effective temperature. Predictions from the new model were in close agreement with the data used to create the model. When predictions from the model were compared with new observations, fail-dangerous predictions were made a majority of the time. When GOL time was predicted exactly, many fail-dangerous predictions shifted toward the fail-safe direction. Two important facts regarding C. perfringens should impact future modeling research with this organism and may have broader food safety policy implications: (i) the normal variability in the response of the organism from replicate to replicate may be quite large (1 log CFU) and may exceed the current U.S. Food Safety Inspection Service performance standard, and (ii) the accuracy of the GOL time model has a profound influence upon the overall prediction, with small differences in GOL time prediction (approximately 1 h) having a very large effect on the predicted final concentration of C. perfringens.
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Affiliation(s)
- Sarah Smith-Simpson
- Food Risk Analysis Initiative, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901-8520, USA
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Abstract
Many meat-based food products are cooked to temperatures sufficient to inactivate vegetative cells of Clostridium perfringens, but spores of this bacterium can survive, germinate, and grow in these products if sufficient time, temperature, and other variables exist. Because ingestion of large numbers of vegetative cells can lead to concomitant sporulation, enterotoxin release in the gastrointestinal tract, and diarrhea-like illness, a necessary food safety objective is to ensure that not more than acceptable levels of C. perfringens are in finished products. As cooked meat items cool they will pass through the growth temperature range of C. perfringens (50 to 15 degrees C). Therefore, an important step in determining the likely level of C. perfringens in the final product is the estimation of growth of the pathogen during cooling of the cooked product. Numerous studies exist dealing with just such estimations, yet consensual methodologies, results, and conclusions are lacking. There is a need to consider the bulk of C. perfringens work relating to cooling of cooked meat-based products and attempt to move toward a better understanding of the true growth potential of the organism. This review attempts to summarize observations made by researchers and highlight variations in experimental approach as possible explanations for different outcomes. An attempt is also made here to identify and justify optimal procedures for conducting C. perfringens growth estimation in meat-based cooked food products during cooling.
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Affiliation(s)
- Peter J Taormina
- John Morrell & Co., 805 East Kemper Road, Cincinnati, Ohio 45246-2515, USA.
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Smith S, Schaffner DW. Evaluation of a predictive model for Clostridium perfringens growth during cooling. J Food Prot 2004; 67:1133-7. [PMID: 15222539 DOI: 10.4315/0362-028x-67.6.1133] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Proper temperature control is essential in minimizing Clostridium perfringens germination, growth, and toxin production. The U.S. Department of Agriculture Food Safety and Inspection Service offers two options for the cooling of meat products: follow a standard time-temperature schedule or validate that alternative cooling regimes result in no more than a 1-log CFU/g increase of C. perfringens and no growth of Clostridium botulinum. The Juneja 1999 model for C. perfringens growth during cooling may be helpful in determining whether the C. perfringens performance standard has been achieved, but this model has not been extensively validated. The objective of this study was to validate the Juneja 1999 model under a variety of temperature situations. The Juneja 1999 model for C. perfringens growth during cooling is fail safe when low (<1 log CFU/ml) or high (>3 log CFU/ml) observed increases occur during exponential cooling. The Juneja 1999 model consistently underpredicted growth at intermediate observed increases (1 to 3 log CFU/ml). The Juneja 1999 model also underpredicted growth whenever exponential cooling took place at two different rates in the first and second portions of the cooling process. This error may be due to faster than predicted growth of C. perfringens cells during cooling or to an inaccuracy in the Juneja 1999 model.
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Affiliation(s)
- Sarah Smith
- Food Risk Analysis Initiative, 65 Dudley Road, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901-8520, USA
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20
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Smith S, Juneja V, Schaffner DW. Influence of several methodological factors on the growth of Clostridium perfringens in cooling rate challenge studies. J Food Prot 2004; 67:1128-32. [PMID: 15222538 DOI: 10.4315/0362-028x-67.6.1128] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Proper temperature control is essential in preventing Clostridium perfringens food poisoning. The U.S. Department of Agriculture Food Safety and Inspection Service cooling guidelines offer two options for the cooling of meat products: follow a standard time-temperature schedule or validate that alternative cooling regimens result in no more than a 1-log CFU/g increase of C. perfringens and no growth of Clostridium botulinum. The latter option requires laboratory challenge studies to validate the efficacy of a given cooling process. Accordingly, the objective of this study was to investigate the role of several methodological variables that might be encountered during typical C. perfringens challenge studies. Variables studied included plastic bag type (Whirlpak or Spiral Biotech), sealing method (Multivac or FoodSaver), initial spore inoculum size (1 to approximately 3 log CFU/g), and growth environment (ground beef or Trypticase-peptone-glucose-yeast extract [TPGY] broth). The major factors that affected growth were sample bag type and growth environment. Samples incubated in Whirlpak bags showed significantly less growth than those incubated in Spiral Biotech bags, which was likely due to the former bag's greater oxygen permeability. C. perfringens spores showed shorter germination, outgrowth, and lag times and C. perfringens cells showed faster growth rates in ground beef compared with TPGY broth. No significant difference was observed between two different sealing methods. Initial spore inoculum levels in the range studied had no significant effect on final C. perfringens cell concentration.
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Affiliation(s)
- Sarah Smith
- Food Risk Analysis Initiative, 65 Dudley Road, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08901-8520, USA
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21
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Smith S, Schaffner DW. Evaluation of a Clostridium perfringens predictive model, developed under isothermal conditions in broth, to predict growth in ground beef during cooling. Appl Environ Microbiol 2004; 70:2728-33. [PMID: 15128525 PMCID: PMC404405 DOI: 10.1128/aem.70.5.2728-2733.2004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2003] [Accepted: 12/29/2003] [Indexed: 11/20/2022] Open
Abstract
Proper temperature control is essential in minimizing Clostridium perfringens germination, growth, and toxin production. The U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS) offers two options for the cooling of meat products: follow a standard time-temperature schedule or validate that alternative cooling regimens result in no more than a 1-log(10) CFU/g increase of C. perfringens and no growth of Clostridium botulinum. A mathematical model developed by Juneja et al. (Food Microbiol. 16:335-349, 1999) may be helpful in determining if the C. perfringens performance standard has been achieved, but this model has not been extensively validated. The objective of this study was to validate the Juneja 1999 model in ground beef under a variety of changing temperature and temperature abuse situations. The Juneja 1999 model consistently underpredicted growth of C. perfringens during exponential cooling of ground beef. The model also underpredicted growth of C. perfringens in ground beef cooled at two different rates. The results presented here show generally good agreement with published data on the growth of C. perfringens in similar products. The model error may be due to faster-than-expected exponential growth rates in ground beef during cooling or an error in the mathematical formulation of the model.
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Affiliation(s)
- Sarah Smith
- Food Risk Analysis Initiative, Rutgers-The State University of New Jersey, New Brunswick, New Jersey 08901-8520, USA
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23
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Juneja V, Whiting R, Marks H, Snyder O. Predictive model for growth of Clostridium perfringens at temperatures applicable to cooling of cooked meat. Food Microbiol 1999. [DOI: 10.1006/fmic.1998.0245] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Blankenship LC, Craven SE, Leffler RG, Custer C. Growth of Clostridium perfringens in cooked chili during cooling. Appl Environ Microbiol 1988; 54:1104-8. [PMID: 2898919 PMCID: PMC202611 DOI: 10.1128/aem.54.5.1104-1108.1988] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
U.S. Department of Agriculture regulations require that brick chili be cooled from 48.9 degrees C to 4.4 degrees C within 2 h of cooking, but processors may not always be able to comply. Studies were conducted to evaluate the extent of bacterial multiplication resulting from outgrowth of germinated Clostridium perfringens spores experimentally inoculated into chili and incubated at various temperatures. Inoculated samples were heated (75 degrees C for 20 min) to activate spores, quickly equilibrated, and held at one of five desired temperatures for 6 h. No growth was observed for C. perfringens in samples held at 26.7 degrees C and below for 6 h, but growth was observed by 6 h in samples held at 32.2 degrees C and after 2 h in samples held at temperatures between 37.8 degrees C and 48.9 degrees C. Using isothermal growth data, we developed a simple model for predicting the growth of bacteria with time under exponential cooling conditions. The model predicts both the lag phase and the numbers of bacteria at specific times during the growth phase. It was developed by using isothermal growth data and tested by using temperature-varying growth data from experiments with spores of C. perfringens in chili. Actual data agreed closely with predicted results. The results should be useful for evaluating the hazard potential for growth of C. perfringens in chili.
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Affiliation(s)
- L C Blankenship
- Richard B. Russell Research Center, U.S. Department of Agriculture, Athens, Georgia 30613
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ROY RJ, BUSTA FF, THOMPSON DR. Thermal Inactivation of Clostridium perfringens After Growth at Several Constant and Linearly Rising Temperatures. J Food Sci 1981. [DOI: 10.1111/j.1365-2621.1981.tb04227.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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