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Heat resistance, membrane fluidity and sublethal damage in Staphylococcus aureus cells grown at different temperatures. Int J Food Microbiol 2019; 289:49-56. [DOI: 10.1016/j.ijfoodmicro.2018.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 07/24/2018] [Accepted: 09/01/2018] [Indexed: 11/21/2022]
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2
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Minor Fernandes Inagaki J, Jagnow Sereno M, Pegoraro K, Zanatta Waz M, Mendonça Soares V, Gonçalves Pereira J, Bersot LDS. Effect of organic matter and pH on the resistance of Salmonella
Typhimurium and Salmonella
Derby in scalding water from pig slaughter. J Food Saf 2018. [DOI: 10.1111/jfs.12504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - Mallu Jagnow Sereno
- Department of Veterinary Science; Federal University of Paraná; Palotina Paraná Brazil
| | - Kadigia Pegoraro
- Department of Veterinary Science; Federal University of Paraná; Palotina Paraná Brazil
| | - Mykaella Zanatta Waz
- Department of Veterinary Science; Federal University of Paraná; Palotina Paraná Brazil
| | | | - Juliano Gonçalves Pereira
- School of Veterinary Medicine and Animal Science; São Paulo State University; Botucatu Campus São Paulo Brazil
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3
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Kh ZH, Kh M, H B, I B, B MBAA. Safety characterization of Yersinia enterocolitica strains isolated from raw milk in Western Algeria. ACTA ACUST UNITED AC 2016. [DOI: 10.5897/ajmr2015.7839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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4
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Neetoo H, Chen H. Influence of Growth Temperatures of S
almonella
and Storage Temperatures of Alfalfa Seeds on Heat Inactivation of the Pathogen during Heat Treatment. J FOOD PROCESS PRES 2015. [DOI: 10.1111/jfpp.12439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Hudaa Neetoo
- Department of Agricultural and Food Sciences; University of Mauritius; Réduit 80837 Mauritius
| | - Haiqiang Chen
- Department of Animal and Food Sciences; University of Delaware; Newark DE
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5
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Laukkanen-Ninios R, Fredriksson-Ahomaa M, Korkeala H. EnteropathogenicYersiniain the Pork Production Chain: Challenges for Control. Compr Rev Food Sci Food Saf 2014. [DOI: 10.1111/1541-4337.12108] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Riikka Laukkanen-Ninios
- Dept. of Food Hygiene and Environmental Health; Faculty of Veterinary Medicine; Univ. of Helsinki; P.O. Box 66, 00014 Helsinki Finland
| | - Maria Fredriksson-Ahomaa
- Dept. of Food Hygiene and Environmental Health; Faculty of Veterinary Medicine; Univ. of Helsinki; P.O. Box 66, 00014 Helsinki Finland
| | - Hannu Korkeala
- Dept. of Food Hygiene and Environmental Health; Faculty of Veterinary Medicine; Univ. of Helsinki; P.O. Box 66, 00014 Helsinki Finland
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6
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Wen X, Li J, Dickson JS. Generalized linear mixed model analysis of risk factors for contamination of moisture-enhanced pork with Campylobacter jejuni and Salmonella enterica Typhimurium. Foodborne Pathog Dis 2014; 11:808-14. [PMID: 25072538 DOI: 10.1089/fpd.2014.1762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Translocation of foodborne pathogens into the interior tissues of pork through moisture enhancement may be of concern if the meat is undercooked. In the present study, a five-strain mixture of Campylobacter jejuni or Salmonella enterica Typhimurium was evenly spread on the surface of fresh pork loins. Pork loins were injected, sliced, vacuum packaged, and stored. After storage, sliced pork was cooked by traditional grilling. Survival of Salmonella Typhimurium and C. jejuni in the interior tissues of the samples were analyzed by enumeration. The populations of these pathogens dropped below the detection limit (10 colony-forming units/g) in most samples that were cooked to 71.1°C or above. The general linear mixed model procedure was used to model the association between risk factors and the presence/absence of these pathogens after cooking. Estimated regression coefficients associated with the fixed effects indicated that the recovery probability of Salmonella Typhimurium was negatively associated with increasing level of enhancement. The effects of moisture enhancement and cooking on the recovery probability of C. jejuni were moderated by storage temperature. Our findings will assist food processors and regulatory agencies with science-based evaluation of the current processing, storage condition, and cooking guideline for moisture-enhanced pork.
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Affiliation(s)
- Xuesong Wen
- 1 Interdepartmental Microbiology Program, Iowa State University , Ames, Iowa
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7
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Growth temperature alters Salmonella Enteritidis heat/acid resistance, membrane lipid composition and stress/virulence related gene expression. Int J Food Microbiol 2014; 172:102-9. [DOI: 10.1016/j.ijfoodmicro.2013.12.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 11/20/2013] [Accepted: 12/04/2013] [Indexed: 11/22/2022]
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8
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Bolton DJ, Ivory C, McDowell D. Thermal inactivation of Yersinia enterocolitica in pork slaughter plant scald tank water. Meat Sci 2013; 95:668-71. [PMID: 23279870 DOI: 10.1016/j.meatsci.2012.11.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 11/09/2012] [Accepted: 11/16/2012] [Indexed: 10/27/2022]
Abstract
The objective of this study was to establish the time-temperature combinations required to ensure the thermal inactivation of Yersinia enterocolitica during scalding of pork carcasses. A 2 strain cocktail of Y. enterocolitica (bioserotypes 2/O:5,27 and 1A/O:6,30) was heat treated at 50, 55 and 60°C in samples of scald tank water obtained from a commercial pork slaughter plant. Samples were removed at regular intervals and surviving cells enumerated using (i) Cefsulodin-Irgasan-Novobiocin Agar (CIN) supplemented with ampicillin and arabinose and (ii) Tryptone Soya Agar (TSA), overlaid with CIN agar with ampicillin and arabinose. The data generated was used to estimate D- and z-values and the formula Dx=log(-1)(log D60-((t2-t1)/z)) was applied to calculate thermal death time-temperature combinations from 55 to 65°C. D50, D55 and D60-values of 45.9, 10.6 and 2.7min were calculated from the cell counts obtained on CIN agar, respectively. The corresponding D-values calculated from the TSA/CIN counts were 45.1, 11 and 2.5min, respectively. The z-value was 7.8. It was concluded that a time-temperature combination of 2.7min at 60°C is required to achieve a 1 log reduction in Y. enterocolitica in pork scald tank water. The predicted equivalent at 65°C was 0.6min. This study provides data and a model to enable pork processors to identify and apply parameters to limit the risk of carcass cross-contamination with Y. enterocolitica in pork carcass scald tanks.
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Affiliation(s)
- Declan J Bolton
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland.
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9
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Condón S, Mañas P, Cebrián G. Manothermosonication for Microbial Inactivation. FOOD ENGINEERING SERIES 2011. [DOI: 10.1007/978-1-4419-7472-3_11] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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10
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Arroyo C, Condón S, Pagán R. Thermobacteriological characterization of Enterobacter sakazakii. Int J Food Microbiol 2009; 136:110-8. [DOI: 10.1016/j.ijfoodmicro.2009.09.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 09/08/2009] [Accepted: 09/13/2009] [Indexed: 10/20/2022]
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11
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ÁLVAREZ-ORDÓÑEZ AVELINO, FERNÁNDEZ ANA, BERNARDO ANA, LÓPEZ MERCEDES. HEAT-RESISTANCE PREDICTION OFLISTERIA INNOCUAGROWN AT DIFFERENT TEMPERATURES. J Food Saf 2009. [DOI: 10.1111/j.1745-4565.2009.00170.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Cebrián G, Sagarzazu N, Pagán R, Condón S, Mañas P. Resistance ofEscherichia coligrown at different temperatures to various environmental stresses. J Appl Microbiol 2008; 105:271-8. [DOI: 10.1111/j.1365-2672.2008.03745.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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13
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FAVIER GABRIELAISABEL, ESCUDERO MARÍAESTHER, DE GUZMÁN ANAMARÍASTEFANINI. THERMAL INACTIVATION OF YERSINIA ENTEROCOLITICA IN LIQUID EGG PRODUCTS. J Food Saf 2008. [DOI: 10.1111/j.1745-4565.2008.00103.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Hassani M, Lázaro R, Pérez C, Condón S, Pagán R. Thermostability of oxytetracycline, tetracycline, and doxycycline at ultrahigh temperatures. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:2676-2680. [PMID: 18373348 DOI: 10.1021/jf800008p] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The thermostability parameters of three tetracycline antibiotics at high and ultrahigh temperatures (110-140 degrees C) as well as the influence of treatment medium pH and water activity on their thermotolerance have been investigated. The thermal degradation of the three antibiotics followed a first-order reaction kinetic within the 1.5-2 log(10) cycles investigated. A linear relationship was observed between the log of the DT values and the treatment temperature. The temperature dependence of the DT values was similar for the three molecules (z=28+/-2 degrees C). DT values of doxycycline were approximately 1.5 and 3 times higher than those of tetracycline and oxytetracycline, respectively. Changes in the treatment medium pH (7.0-4.0) and water activity (0.99-0.93) scarcely varied the antibiotics' thermal stability. Only when doxycycline was heat-treated at pH 4.0 did its thermal resistance increase by 3 times. The thermostability parameters obtained would allow the effect of different cooking and sterilization procedures to be estimated. Whereas low-temperature-long-time treatments (conventional sterilization) would destroy >98% of the initial concentration of the residues of the three antibiotics, high-temperature-short-time treatments (UHT) would leave unaltered residues in the 50-90% range.
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Affiliation(s)
- Mounir Hassani
- Produccion Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, C/Miguel Servet 177, 50013 Zaragoza, Spain
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15
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Álvarez-Ordóñez A, Fernández A, López M, Arenas R, Bernardo A. Modifications in membrane fatty acid composition of Salmonella typhimurium in response to growth conditions and their effect on heat resistance. Int J Food Microbiol 2008; 123:212-9. [DOI: 10.1016/j.ijfoodmicro.2008.01.015] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 01/29/2008] [Accepted: 01/30/2008] [Indexed: 10/22/2022]
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16
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Effect of environmental factors and cell physiological state on Pulsed Electric Fields resistance and repair capacity of various strains of Escherichia coli. Int J Food Microbiol 2008; 124:260-7. [PMID: 18455818 DOI: 10.1016/j.ijfoodmicro.2008.03.021] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Revised: 02/18/2008] [Accepted: 03/24/2008] [Indexed: 11/23/2022]
Abstract
The aim was to determine the resistance variation of four strains of Escherichia coli to Pulsed Electric Fields (PEF), the role of the sigma factor RpoS in PEF resistance, as well as the influence of several environmental factors and the cell physiological state on the PEF resistance and repair capacity. The rpoS null mutant, E. coli BJ4L1, exhibited decreased PEF resistance as compared with its wild-type parent, BJ4. W3110 and O157:H7 were the most PEF-resistant strains: whereas 2 and more than 3 Log10 cycles of BJ4 and BJ4L1 cells, respectively, were inactivated after 50 pulses at 35 kV/cm, only 0.5 Log10 cycle of inactivation of W3110 and O157:H7 was attained. A different pattern was observed and the resistance variation among strains was largely reduced, when selective recovery media were used. At exponential growth phase, the resistance of the four strains was lower, and more than 4 Log10 cycles of inactivation of all strains tested were attained at 30 kV/cm. Previous heat and cold shock treatments scarcely influenced cell PEF resistance. PEF survival increased with the reduction in water activity of the treatment medium to 0.94: the occurrence of sublethally injured cells was negligible, and less than 1 Log10 cycle of inactivation was attained at 35 kV/cm. PEF-treated cells were sensitive to a subsequent storage at pH 4.0 or in the presence of sorbic acid, attaining a final inactivation of 4-5 Log10 cycles after 24 hour-incubation. In conclusion, the work confirms the role of rpoS in PEF resistance. E. coli strains exhibit large differences in PEF resistance. These differences were less important when cells were recovered under selective conditions. Both resistance variation among strains and occurrence of sublethal damage were noticeably influenced by the environmental factors tested.
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17
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McQuestin OJ, McMeekin TA, Ross T. Effect of suspension media on nonthermal inactivation ofEscherichia coli. Lett Appl Microbiol 2006; 43:523-7. [PMID: 17032226 DOI: 10.1111/j.1472-765x.2006.01993.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS To investigate the influence of suspension media on the survival of Escherichia coli M23 exposed to nonthermal, lethal stresses. METHODS AND RESULTS Populations of E. coli M23 suspended in minimal medium (MM) or in different nutrient-rich broths were exposed to water activity 0.90 and/or pH 3.5 and inactivation was determined by culture-based enumeration. In response to the osmotic or acid challenges, E. coli M23 displayed enhanced survival in MM rather than in complex broth. That trend was reversed when populations were exposed to low water activity in combination with low pH. Comparison of microbial survival in three complex media indicated that even relatively small differences in composition influenced inactivation. In most media the combination of lethal stresses resulted in a synergism, which enhanced bacterial inactivation; however, an exception (tryptone soya broth) was observed. CONCLUSIONS The suspension medium strongly influences the inactivation of E. coli M23 by osmotic and/or acid stresses. This should be considered when comparing studies of microbial survival that use different media and when broth-derived data are intended to represent specific environments (e.g. food matrices). SIGNIFICANCE AND IMPACT OF THE STUDY The specific effects of synthetic media need to be appreciated when studying bacterial inactivation in conditions relevant to food-manufacturing regimes.
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Affiliation(s)
- O J McQuestin
- Australian Food Safety Centre of Excellence, School of Agricultural Science, University of Tasmania, Hobart, Tasmania, Australia.
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Spinks AT, Dunstan RH, Harrison T, Coombes P, Kuczera G. Thermal inactivation of water-borne pathogenic and indicator bacteria at sub-boiling temperatures. WATER RESEARCH 2006; 40:1326-32. [PMID: 16524613 DOI: 10.1016/j.watres.2006.01.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Revised: 01/22/2006] [Accepted: 01/23/2006] [Indexed: 05/07/2023]
Abstract
The use of harvested rainwater in domestic hot water systems can result in optimised environmental and economic benefits to urban water cycle management, however, the water quality and health risks of such a scenario have not been adequately investigated. Thermal inactivation analyses were carried out on eight species of non-spore-forming bacteria in a water medium at temperatures relevant to domestic hot water systems (55-65 degrees C), and susceptibilities to heat stress were compared using D-values. The D-value was defined as the time required to reduce a bacterial population by 90% or 1 log reduction. The results found that both tested strains of Enterococcus faecalis were the most heat resistant of the bacteria studied, followed by the pathogens Shigella sonnei biotype A and Escherichia coli O157:H7, and the non-pathogenic E. coli O3:H6. Pseudomonas aeruginosa was found to be less resistant to heat, while Salmonella typhimurium, Serratia marcescens, Klebsiella pneumoniae and Aeromonas hydrophila displayed minimal heat resistance capacities. At 65 degrees C, little thermal resistance was demonstrated by any species, with log reductions in concentration occurring within seconds. The results of this study suggested that the temperature range from 55 to 65 degrees C was critical for effective elimination of enteric/pathogenic bacterial components and supported the thesis that hot water systems should operate at a minimum of 60 degrees C.
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Affiliation(s)
- Anthony T Spinks
- School of Environmental & Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
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Hayashidani H, Hara-Kudo Y, Kinoshita S, Saeki K, Okatani AT, Nomura Y, Kumagai S. Differences in heat resistance among pathogenic Yersinia enterocolitica depended on growth temperature and serotype. J Food Prot 2005; 68:1081-2. [PMID: 15895746 DOI: 10.4315/0362-028x-68.5.1081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
To gain a better understanding about the effect of growth temperature on heat resistance of Yersinia enterocolitica, we determined decimal reduction times at 60 degrees C (D60-values) for O:3; O:5,27; O:8; and O:9 strains harboring virulence plasmid coding for Yersinia outer membrane protein and experimentally virulence plasmid-deleted strains after they were grown to stationary phase at 7, 25, or 37 degrees C. Bacteria were inoculated into Trypticase soy broth and were incubated at several temperatures. D60-values of O:3; O:5,27; and O:8 strains were larger when they were grown at 37 degrees C than at 7 or 25 degrees C, despite the presence or absence of virulence plasmids. However, similar D60-values were observed in O:9 strains, despite growth at 7, 25, or 37 degrees C. The results indicate two types of Y. enterocolitica strains, growth temperature-dependent and -independent, and a Yersinia outer membrane protein that is not directly involved in growth temperature-dependent heat resistance.
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Affiliation(s)
- H Hayashidani
- Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
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Raso J, Condon S, Pagan R. Microbial Inactivation by Ultrasound. NOVEL FOOD PROCESSING TECHNOLOGIES 2004. [DOI: 10.1201/9780203997277.ch19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Martínez S, López M, Bernardo A. Thermal inactivation of Enterococcus faecium: effect of growth temperature and physiological state of microbial cells. Lett Appl Microbiol 2003; 37:475-81. [PMID: 14633102 DOI: 10.1046/j.1472-765x.2003.01431.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To provide data on the effects on culture temperature and physiological state of cells on heat resistance of Enterococcus faecium, which may be useful in establishing pasteurization procedures. METHODS AND RESULTS The heat resistance of this Ent. faecium (ATCC 49624 strain) grown at different temperatures was monitored at various stages of growth. In all cases, the bacterial cells in the logarithmic phase of growth were more heat sensitive. For cells which had entered in the stationary phase, D70 values of 0.53 min at 5 degrees C, 0.74 min at 10 degrees C, 0.83 min at 20 degrees C, 0.79 min at 30 degrees C, 0.63 min at 37 degrees C, 0.48 min at 40 degrees C and 0.41 min at 45 degrees C were found. By extending the incubation times cells were more heat resistant as stationary phase progressed, although a different pattern was observed for cells grown at different temperatures. At the lower temperatures heat resistance increased progressively, reaching D70 values of 1.73 min for cells incubated at 5 degrees C for 50 days and 1.04 min for those grown at 10 degrees C for 16 days. At other temperatures assayed heat resistance became stable for late stationary phase cells, reaching D70 values of 1.05, 1.08 and 1.01 min for cultures incubated at 20, 30 and 37 degrees C. Heat resistance of cells obtained at higher temperatures, 40 and 45 degrees C, was significantly lower, with D70 values of 0.76 and 0.67 min, respectively. Neither the growth temperature nor the growth phase modified the z-values significantly. CONCLUSIONS D70 values obtained for Ent. faecium (ATCC 49624) varies from 0.33 to 1.73 min as a function of culture temperature and physiological state of cells. However, z values calculated were not significantly influenced by these factors. A mean value of 4.50 +/- 0.39 degrees C was found. SIGNIFICANCE AND IMPACT OF THE STUDY Overall results strongly suggest that, to establish heat processing conditions of pasteurized foods ensuring elimination of Ent. faecium, it is advisable to take into account the complex interaction of growth temperature and growth phase of cells acting on bacterial thermal resistance.
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Affiliation(s)
- S Martínez
- Tecnología de los Alimentos, Facultad de Ciencias de Ourense, Universidad de Vigo, Spain
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Mañas P, Pagán R, Raso J, Condón S. Predicting thermal inactivation in media of different pH of Salmonella grown at different temperatures. Int J Food Microbiol 2003; 87:45-53. [PMID: 12927706 DOI: 10.1016/s0168-1605(03)00049-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The influence of the growth temperature and the pH of the heating medium on the heat resistance at different temperatures of Salmonella typhimurium ATCC 13311 was studied and described mathematically. The shift of the growth temperature from 10 to 37 degrees C increased heat resistance of S. typhimurium fourfold. The pH of the heating medium at which heat resistance was maximum was pH 6 for cells grown at 37 degrees C, but changed with growth temperature. The alkalinization of the heating medium from pH 6 to pH 7.7 decreased the heat resistance of cells grown at 37 degrees C by a factor of 3. Neither the growth temperature nor the pH modified the z values significantly (4.9 degrees C). The decimal reduction times at different treatment temperatures, in buffers of different pH of cells of S. typhimurium grown at different temperatures, were accurately described by a mathematical equation (correlation coefficient of 0.97). This equation was also tested for Salmonella senftenberg 775W (ATCC 43845) and Salmonella enteritidis ATCC 13076, strains in which the correlation coefficients between the observed and the theoretically calculated values were 0.91 and 0.98, respectively.
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Affiliation(s)
- Pilar Mañas
- Tecnología de los Alimentos, Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, C/ Miguel Servet, 177, 50013 Zaragoza, Spain
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Sörqvist S. Heat resistance in liquids of Enterococcus spp., Listeria spp., Escherichia coli, Yersinia enterocolitica, Salmonella spp. and Campylobacter spp. Acta Vet Scand 2003; 44:1-19. [PMID: 14650540 PMCID: PMC1831557 DOI: 10.1186/1751-0147-44-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2002] [Accepted: 10/28/2002] [Indexed: 11/19/2022] Open
Abstract
The aim of the work was to collect, evaluate, summarize and compare heat resistance data reported for Campylobacter, Enterococcus, Escherichia, Listeria, Salmonella and Yersinia spp. The work was limited to resistance in liquids with pH values 6-8. Results obtained under similar experimental conditions were sought. Thermal destruction lines for the various bacterial groups studied were constructed using log10 D values and treatment temperatures. There was a good linear relationship between log10 D and temperature with Escherichia coli, listerias and salmonellas. For campylobacters, enterococci and yersinias the relationships were weaker but, nevertheless, present. Using the slopes of the lines and their 95% confidence limits, z values and their 95% confidence limits were calculated. z values were compared with z values obtained from reports. The equations for the lines were also used for calculation of predicted means of D values at various treatment temperatures. 95% confidence limits on predicted means of D values and on predicted individual D values were also calculated. Lines and values are shown in figures and tables. Differences in heat resistance noted between and within the bacterial groups studied are discussed.
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Affiliation(s)
- S Sörqvist
- Department of Food Hygiene, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden.
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