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Macleod J, Beeton ML, Blaxland J. An Exploration of Listeria monocytogenes, Its Influence on the UK Food Industry and Future Public Health Strategies. Foods 2022; 11:1456. [PMID: 35627026 PMCID: PMC9141670 DOI: 10.3390/foods11101456] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 02/04/2023] Open
Abstract
Listeria monocytogenes is a Gram-positive intracellular pathogen that can cause listeriosis, an invasive disease affecting pregnant women, neonates, the elderly, and immunocompromised individuals. Principally foodborne, the pathogen is transmitted typically through contaminated foods. As a result, food manufacturers exert considerable efforts to eliminate L. monocytogenes from foodstuffs and the environment through food processing and disinfection. However, L. monocytogenes demonstrates a range of environmental stress tolerances, resulting in persistent colonies that act as reservoirs for the reintroduction of L. monocytogenes to food contact surfaces and food. Novel technologies for the rapid detection of L. monocytogenes and disinfection of food manufacturing industries have been developed to overcome these obstacles to minimise the risk of outbreaks and sporadic cases of listeriosis. This review is aimed at exploring L. monocytogenes in the UK, providing a summary of outbreaks, current routine microbiological testing and the increasing awareness of biocide tolerances. Recommendations for future research in the UK are made, pertaining to expanding the understanding of L. monocytogenes dissemination in the UK food industry and the continuation of novel technological developments for disinfection of food and the food manufacturing environment.
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Affiliation(s)
- Joshua Macleod
- Microbiology and Infection Research Group, School of Sport and Health Sciences, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, UK; (J.M.); (M.L.B.)
- ZERO2FIVE Food Industry Centre, Llandaff Campus, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, UK
| | - Michael L. Beeton
- Microbiology and Infection Research Group, School of Sport and Health Sciences, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, UK; (J.M.); (M.L.B.)
| | - James Blaxland
- Microbiology and Infection Research Group, School of Sport and Health Sciences, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, UK; (J.M.); (M.L.B.)
- ZERO2FIVE Food Industry Centre, Llandaff Campus, Cardiff Metropolitan University, Western Avenue, Cardiff CF5 2YB, UK
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2
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Timmermans R, Mastwijk H, Berendsen L, Nederhoff A, Matser A, Van Boekel M, Nierop Groot M. Moderate intensity Pulsed Electric Fields (PEF) as alternative mild preservation technology for fruit juice. Int J Food Microbiol 2019; 298:63-73. [DOI: 10.1016/j.ijfoodmicro.2019.02.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 01/11/2019] [Accepted: 02/18/2019] [Indexed: 01/11/2023]
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3
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Bucur FI, Grigore-Gurgu L, Crauwels P, Riedel CU, Nicolau AI. Resistance of Listeria monocytogenes to Stress Conditions Encountered in Food and Food Processing Environments. Front Microbiol 2018; 9:2700. [PMID: 30555426 PMCID: PMC6282059 DOI: 10.3389/fmicb.2018.02700] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/23/2018] [Indexed: 12/17/2022] Open
Abstract
Listeria monocytogenes is a human food-borne facultative intracellular pathogen that is resistant to a wide range of stress conditions. As a consequence, L. monocytogenes is extremely difficult to control along the entire food chain from production to storage and consumption. Frequent and recent outbreaks of L. monocytogenes infections illustrate that current measures of decontamination and preservation are suboptimal to control L. monocytogenes in food. In order to develop efficient measures to prevent contamination during processing and control growth during storage of food it is crucial to understand the mechanisms utilized by L. monocytogenes to tolerate the stress conditions in food matrices and food processing environments. Food-related stress conditions encountered by L. monocytogenes along the food chain are acidity, oxidative and osmotic stress, low or high temperatures, presence of bacteriocins and other preserving additives, and stresses as a consequence of applying alternative decontamination and preservation technologies such high hydrostatic pressure, pulsed and continuous UV light, pulsed electric fields (PEF). This review is aimed at providing a summary of the current knowledge on the response of L. monocytogenes toward these stresses and the mechanisms of stress resistance employed by this important food-borne bacterium. Circumstances when L. monocytogenes cells become more sensitive or more resistant are mentioned and existence of a cross-resistance when multiple stresses are present is pointed out.
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Affiliation(s)
- Florentina Ionela Bucur
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Leontina Grigore-Gurgu
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
| | - Peter Crauwels
- Institute of Microbiology and Biotechnology, Ulm University, Ulm, Germany
| | | | - Anca Ioana Nicolau
- Faculty of Food Science and Engineering, Dunarea de Jos University of Galati, Galati, Romania
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Raso J, Frey W, Ferrari G, Pataro G, Knorr D, Teissie J, Miklavčič D. Recommendations guidelines on the key information to be reported in studies of application of PEF technology in food and biotechnological processes. INNOV FOOD SCI EMERG 2016. [DOI: 10.1016/j.ifset.2016.08.003] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Huang YT, Ko WC, Chan YJ, Lu JJ, Tsai HY, Liao CH, Sheng WH, Teng LJ, Hsueh PR. Disease Burden of Invasive Listeriosis and Molecular Characterization of Clinical Isolates in Taiwan, 2000-2013. PLoS One 2015; 10:e0141241. [PMID: 26555445 PMCID: PMC4640856 DOI: 10.1371/journal.pone.0141241] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 10/06/2015] [Indexed: 01/25/2023] Open
Abstract
The information about disease burden and epidemiology of invasive listeriosis in Asia is scarce. From 2000 to 2013, a total of 338 patients with invasive listeriosis (bacteremia, meningitis, and peritonitis) were treated at four medical centers in Taiwan. The incidence (per 10,000 admissions) of invasive listeriosis increased significantly during the 14-year period among the four centers (0.15 in 2000 and >1.25 during 2010-2012) and at each of the four medical centers. Among these patients, 45.9% were elderly (>65 years old) and 3.3% were less than one year of age. More than one-third (36.7%) of the patients acquired invasive listeriosis in the spring (April to June). Among the 132 preserved Listeria monocytogenes isolates analyzed, the most frequently isolated PCR serogroup-sequence type (ST) was IIb-ST87 (23.5%), followed by IIa-ST378 (19.7%) and IIa-ST155 (12.1%). Isolation of PCR serogroups IIb and IVb increased significantly with year, with a predominance of IIb-ST87 isolates (23.5%) and IIb-ST 228 isolates emerging in 2013. A total of 12 different randomly amplified polymorphic DNA (RAPD) patterns (Patterns I to XII) were identified among the 112 L. monocytogenes isolates belonging to eight main PCR serogroup-STs. Identical RAPD patterns were found among the isolates exhibiting the same PCR serogroup-ST. In conclusion, our study revealed that during 2000-2013, listeriosis at four medical centers in Taiwan was caused by heterogeneous strains and that the upsurge in incidence beginning in 2005 was caused by at least two predominant clones.
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Affiliation(s)
- Yu-Tsung Huang
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
- Graduate Institute of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Wen-Chien Ko
- Department of Internal Medicine, National Cheng Kung University Hospital and Medical College, Tainan, Taiwan
| | - Yu-Jiun Chan
- Department of Laboratory Medicine, Taipei Veterans General Hospital and National Yang-Ming University, Taipei, Taiwan
| | - Jang-Jih Lu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Hsih-Yeh Tsai
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Chun-Hsing Liao
- Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Wang-Huei Sheng
- Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Lee-Jene Teng
- Graduate Institute of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University, Taipei, Taiwan
| | - Po-Ren Hsueh
- Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
- * E-mail:
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Wu X, Liu L, Zhang Z, Deng F, Liu X. Phylogenetic and genetic characterization of Acidithiobacillus strains isolated from different environments. World J Microbiol Biotechnol 2014; 30:3197-209. [PMID: 25252934 DOI: 10.1007/s11274-014-1747-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 09/19/2014] [Indexed: 11/28/2022]
Abstract
To study the phylogenetic relationships and genetic heterogeneity of 21 Acidithiobacillus strains isolated from different environments, we amplified and sequenced the 16S-23S rRNA gene intergenic spacers (ITS) of all these strains. These sequence data, combined with related sequences available from GenBank, were divided into six phylogenetic groups by 16S rRNA gene and by 16S-23S rRNA gene sequence analysis. The results of phylogenetic analysis were consistent with those obtained by repetitive element PCR and arbitrarily primed PCR. In this research, the Acidithiobacillus ferrooxidans (A. ferrooxidans) strains were always separated into two groups in phylogenetic and cluster analyses. Genotypic analyses of the genes rusA, rusB, hip and iro suggest that these two groups may have different biochemical mechanisms for oxidizing ferrous iron. Strains in one A. ferrooxidans group were detected with rusA gene that encodes rusticyanin A which plays a very important role in the iron respiratory chain. The second A. ferrooxidans group was found to contain rusB gene which encode a homologous protein (RusB). The data suggested that ITS-based phylogeny is an effective tool to elucidate the relationships of Acidithiobacillus and that a different iron oxidation pathway may exist in different A. ferrooxidans groups.
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Affiliation(s)
- Xueling Wu
- School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Biobuilding, Lushan South Road 932, Yuelu District, Changsha, 410083, Hunan Province, People's Republic of China
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Saldaña G, Álvarez I, Condón S, Raso J. Microbiological Aspects Related to the Feasibility of PEF Technology for Food Pasteurization. Crit Rev Food Sci Nutr 2014; 54:1415-26. [DOI: 10.1080/10408398.2011.638995] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Effectiveness of combined Pulsed Electric Field (PEF) and Manothermosonication (MTS) for the control of Listeria innocua in a smoothie type beverage. Food Control 2012. [DOI: 10.1016/j.foodcont.2011.11.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Saldaña G, Monfort S, Condón S, Raso J, Álvarez I. Effect of temperature, pH and presence of nisin on inactivation of Salmonella Typhimurium and Escherichia coli O157:H7 by pulsed electric fields. Food Res Int 2012. [DOI: 10.1016/j.foodres.2011.03.059] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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Golberg A, Rae CS, Rubinsky B. Listeria monocytogenes cell wall constituents exert a charge effect on electroporation threshold. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1818:689-94. [PMID: 22100748 PMCID: PMC3366149 DOI: 10.1016/j.bbamem.2011.11.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 10/13/2011] [Accepted: 11/02/2011] [Indexed: 11/17/2022]
Abstract
Genetically engineered cells with mutations of relevance to electroporation, cell membrane permeabilization by electric pulses, can become a promising new tool for fundamental research on this important biotechnology. Listeria monocytogenes mutants lacking DltA or MprF and assayed for sensitivity to the cathelicidin like anti-microbial cationic peptide (mCRAMP), were developed to study the effect of cell wall charge on electroporation. Working in the irreversible electroporation regime (IRE), we found that application of a sequence of 50 pulses, each 50μs duration, 12.5kV/cm field, delivered at 2Hz led to 2.67±0.29 log reduction in wild-type L. monocytogenes, log 2.60±0.19 in the MprF-minus mutant, and log 1.33±0.13 in the DltA-minus mutant. The experimental observation that the DltA-minus mutant was highly susceptible to cationic mCRAMP and resistant to IRE suggests that the charge on the bacterial cell wall affects electroporation and shows that this approach may be promising for fundamental studies on electroporation.
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Affiliation(s)
- Alex Golberg
- Department of Mechanical Engineering, University of California, Berkeley, CA 94720, USA.
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Waite-Cusic JG, Diono BHS, Yousef AE. Screening for Listeria monocytogenes surrogate strains applicable to food processing by ultrahigh pressure and pulsed electric field. J Food Prot 2011; 74:1655-61. [PMID: 22004812 DOI: 10.4315/0362-028x.jfp-11-099] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ultrahigh pressure (UHP) and pulsed electric field (PEF) are emerging processing technologies developed to enhance the safety while maintaining the fresh-like quality of food. For each food and process combination, a pathogen of concern (i.e., target pathogen) must be determined, and a low-risk microorganism that serves as the pathogen surrogate for process validation must be identified. The objective of this study was to identify a surrogate for Listeria monocytogenes for UHP and PEF process validation. Potential surrogates tested include four Lactobacillus spp., a Pediococcus sp., and a Listeria innocua strain. These were compared with nine L. monocytogenes strains, with regard to sensitivity to UHP and PEF processing. For UHP treatment, the strains were suspended in citrate-phosphate buffer (pH 7.0 or 4.5), sweet whey, or acidified whey and pressure processed at 500 MPa for 1 min. For PEF treatment, the strains were suspended in NaCl solution, acid whey, or sweet whey and processed at 25 kV/cm. The lethality of UHP or PEF treatment varied considerably, depending on medium types and pH and the treated strain. Treating the tested microorganisms with UHP inactivated 0.3 to 6.9 log CFU/ml for L. monocytogenes strains and 0.0 to 4.7 log CFU/ml for the potential surrogates. When PEF was employed, populations of tested microorganisms decreased < 1.0 to 5.3 log CFU/ml. L. monocytogenes V7 and OSY-8578 were among the most resistant strains to UHP and PEF treatments, and thus are candidate target strains. Lactobacillus plantarum ATCC 8014 demonstrated similar or greater resistance compared with the target organisms; therefore, the bacterium is proposed as a surrogate of L. monocytogenes for both processes under the conditions specified in the food matrices tested in this study.
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Affiliation(s)
- Joy G Waite-Cusic
- Department of Food Science and Technology, 2015 Fyffe Court, The Ohio State University, Columbus, Ohio 43210, USA
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12
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Saldaña G, Minor-Pérez H, Raso J, Álvarez I. Combined Effect of Temperature, pH, and Presence of Nisin on Inactivation of Staphylococcus aureus and Listeria monocytogenes by Pulsed Electric Fields. Foodborne Pathog Dis 2011; 8:797-802. [DOI: 10.1089/fpd.2010.0788] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Guillermo Saldaña
- Tecnología de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain
| | - Hugo Minor-Pérez
- Tecnológico de Estudios Superiores de Ecatepec, Ecatepec, Mexico
| | - Javier Raso
- Tecnología de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain
| | - Ignacio Álvarez
- Tecnología de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain
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Monfort S, Gayán E, Raso J, Condón S, Álvarez I. Evaluation of pulsed electric fields technology for liquid whole egg pasteurization. Food Microbiol 2010; 27:845-52. [DOI: 10.1016/j.fm.2010.05.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 05/03/2010] [Accepted: 05/08/2010] [Indexed: 12/01/2022]
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Synergistic effect of high pressure processing and Lactobacillus casei antimicrobial activity against pressure resistant Listeria monocytogenes. N Biotechnol 2010; 27:403-8. [DOI: 10.1016/j.nbt.2010.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 04/09/2010] [Accepted: 04/29/2010] [Indexed: 11/20/2022]
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Electroporation of Cell Membranes: The Fundamental Effects of Pulsed Electric Fields in Food Processing. FOOD ENGINEERING REVIEWS 2010. [DOI: 10.1007/s12393-010-9023-3] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Modeling inactivation kinetics and occurrence of sublethal injury of a pulsed electric field-resistant strain of Escherichia coli and Salmonella Typhimurium in media of different pH. INNOV FOOD SCI EMERG 2010. [DOI: 10.1016/j.ifset.2010.01.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Saldaña G, Puértolas E, López N, García D, Álvarez I, Raso J. Comparing the PEF resistance and occurrence of sublethal injury on different strains of Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes and Staphylococcus aureus in media of pH 4 and 7. INNOV FOOD SCI EMERG 2009. [DOI: 10.1016/j.ifset.2008.11.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ni Y, Wan D, He K. 16S rDNA and 16S-23S internal transcribed spacer sequence analyses reveal inter- and intraspecific Acidithiobacillus phylogeny. MICROBIOLOGY-SGM 2008; 154:2397-2407. [PMID: 18667572 DOI: 10.1099/mic.0.2007/016295-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In order to contribute to our understanding of Acidithiobacillus taxonomy, we determined 16S rDNA sequences and the 16S-23S internally transcribed spacer (ITS) sequence of 35 Chinese Acidithiobacillus isolates and three reference strains representing three validly described species and used them to construct phylogenetic trees. The two phylogenetic trees were roughly similar topologically, and Acidithiobacillus strains were assigned to eight phylogenetic groups. In addition, the results of phylogenetic analysis were consistent with those obtained by randomly amplified polymorphic DNA (RAPD) cluster analysis. Compared with a phylogenetic tree based on the 16S rRNA sequences, the ITS tree showed more clearly the inter- and intraspecific genealogical relationships of the genus Acidithiobacillus. Similarity values of the ITSs varied from 60.5 % to 84.7 % between representative strains of different species, and the maximum level of ITS divergence between strains belonging to the same species was 13 %. Coupling phylogenetic analysis and phenotypic characteristics, we concluded that at least each of the three Acidithiobacillus ferrooxidans phylogenetic groups should be considered a separate subspecies, and that five sulfur-oxidizing Chinese Acidithiobacillus-like isolates represent one or two new species of the genus Acidithiobacillus. The ITS may be a potential target for the development of fluorescent in situ hybridization probes for more accurately detecting distinct ecotypes of Acidithiobacillus strains and other closely related sulfur-oxidizing bacteria.
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Affiliation(s)
- Yongqing Ni
- School of Food Sciences, Shihezi University, Shihezi, PR China
| | - Dongshi Wan
- School of Life Sciences, Lanzhou University, Lanzhou, PR China
| | - Kaiyu He
- School of Life Sciences, Lanzhou University, Lanzhou, PR China
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Ni YQ, He KY, Bao JT, Yang Y, Wan DS, Li HY. Genomic and phenotypic heterogeneity of Acidithiobacillus spp. strains isolated from diverse habitats in China. FEMS Microbiol Ecol 2008; 64:248-59. [PMID: 18373686 DOI: 10.1111/j.1574-6941.2008.00457.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The genetic variability among 32 Chinese Acidithiobacillus spp. environmental isolates and four reference strains representing three recognized species of the genus Acidithiobacillus was characterized by using a combination of molecular methods, namely restriction fragment length polymorphisms of PCR-amplified 16S rRNA genes and 16S-23S rRNA gene intergenic spacers, repetitive element PCR, arbitrarily primed PCR and 16S rRNA gene sequence analyses. 16S rRNA gene sequences revealed that all Acidithiobacillus spp. strains could be assigned to seven groups, three of which encompassed the Acidithiobacillus ferrooxidans strains from various parts of the world. A comparative analysis of the phylogenetic Group 1 and 2 was undertaken. Restriction fragment length polymorphism results allowed us to separate the 35 Acidithiobacillus strains into 15 different genotypes. An integrated phenotypic and genotypic analysis indicated that the distribution of A. ferrooxidans strains among the physiological groups were in agreement with their distribution among the genomic groups, and that no clear correlation was found between the genetic polymorphism of the Acidithiobacillus spp. strains and either the geographic location or type of habitats from which the strains were isolated. In addition, five unidentified sulfur-oxidizing isolates may represent one or two novel species of the genus Acidithiobacillus. The results showed that the Chinese Acidithiobacillus spp. isolates exhibited a high degree of genomic and phenotypic heterogeneity.
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Affiliation(s)
- Yong-Qing Ni
- Key Laboratory of Arid and Grassland Ecology of the Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, China
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Toepfl S, Mathys A, Heinz V, Knorr D. Review: Potential of High Hydrostatic Pressure and Pulsed Electric Fields for Energy Efficient and Environmentally Friendly Food Processing. FOOD REVIEWS INTERNATIONAL 2006. [DOI: 10.1080/87559120600865164] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Rodríguez-Calleja JM, Cebrián G, Condón S, Mañas P. Variation in resistance of natural isolates of Staphylococcus aureus to heat, pulsed electric field and ultrasound under pressure. J Appl Microbiol 2006; 100:1054-62. [PMID: 16630006 DOI: 10.1111/j.1365-2672.2006.02868.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To study and compare the resistance of 15 Staphylococcus aureus isolates to heat, pulsed electric field (PEF) and ultrasound (UW) under pressure (manosonication, MS). METHODS AND RESULTS Survival curves to heat (58 degrees C), to PEF (22 kV cm(-1), 2 micros square wave pulses) and to UW under pressure (117 microm, 20 kHz, 200 kPa) were obtained and inactivation parameters (decimal reduction times for heat and UW under pressure, and b-values for PEF) were calculated. A wide resistance variation to heat treatment, but not to PEF and MS, was observed amongst the 15 strains. CONCLUSIONS There was no relationship between the resistances to the three physical agents studied. Staphylococcus aureus was relatively resistant to MS but sensitive to PEF. Heat resistance varied with strain and was positively correlated to carotenoid pigment content. SIGNIFICANCE AND IMPACT OF THE STUDY Results would help in defining safe food preservation processes. Care should be taken to choose the most adequate strain of S. aureus to model food preservation processing.
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Affiliation(s)
- J M Rodríguez-Calleja
- Tecnología de los Alimentos, Facultad de Veterinaria de Zaragoza, Universidad de Zaragoza, Zaragoza, Spain
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Malone AS, Chung YK, Yousef AE. Genes of Escherichia coli O157:H7 that are involved in high-pressure resistance. Appl Environ Microbiol 2006; 72:2661-71. [PMID: 16597971 PMCID: PMC1449011 DOI: 10.1128/aem.72.4.2661-2671.2006] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Seventeen Escherichia coli O157:H7 strains were treated with ultrahigh pressure at 500 MPa and 23 +/- 2 degrees C for 1 min. This treatment inactivated 0.6 to 3.4 log CFU/ml, depending on the strain. The diversity of these strains was confirmed by pulsed-field gel electrophoresis (PFGE) analysis, and there was no apparent association between PFGE banding patterns and pressure resistance. The pressure-resistant strain E. coli O157:H7 EC-88 (0.6-log decrease) and the pressure-sensitive strain ATCC 35150 (3.4-log decrease) were treated with a sublethal pressure (100 MPa for 15 min at 23 +/- 2 degrees C) and subjected to DNA microarray analysis using an E. coli K-12 antisense gene chip. High pressure affected the transcription of many genes involved in a variety of intracellular mechanisms of EC-88, including the stress response, the thiol-disulfide redox system, Fe-S cluster assembly, and spontaneous mutation. Twenty-four E. coli isogenic pairs with mutations in the genes regulated by the pressure treatment were treated with lethal pressures at 400 MPa and 23 +/- 2 degrees C for 5 min. The barotolerance of the mutants relative to that of the wild-type strains helped to explain the results obtained by DNA microarray analysis. This study is the first report to demonstrate that the expression of Fe-S cluster assembly proteins and the fumarate nitrate reductase regulator decreases the resistance to pressure, while sigma factor (RpoE), lipoprotein (NlpI), thioredoxin (TrxA), thioredoxin reductase (TrxB), a trehalose synthesis protein (OtsA), and a DNA-binding protein (Dps) promote barotolerance.
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Affiliation(s)
- Aaron S Malone
- Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Road, Columbus, OH 43210, USA
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Requisite scientific parameters for establishing the equivalence of alternative methods of pasteurization. J Food Prot 2006; 69:1190-216. [PMID: 16715826 DOI: 10.4315/0362-028x-69.5.1190] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24
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Pagán R, Mañas P. Fundamental Aspects of Microbial Membrane Electroporation. PULSED ELECTRIC FIELDS TECHNOLOGY FOR THE FOOD INDUSTRY 2006. [DOI: 10.1007/978-0-387-31122-7_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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25
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Álvarez I, Condón S, Raso J. Microbial Inactivation by Pulsed Electric Fields. PULSED ELECTRIC FIELDS TECHNOLOGY FOR THE FOOD INDUSTRY 2006. [DOI: 10.1007/978-0-387-31122-7_4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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26
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García D, Gómez N, Raso J, Pagán R. Bacterial resistance after pulsed electric fields depending on the treatment medium pH. INNOV FOOD SCI EMERG 2005. [DOI: 10.1016/j.ifset.2005.04.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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27
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Affiliation(s)
- P Mañas
- Tecnología de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, C/Miguel Servet 177, 50013 Zaragoza, Spain.
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Aronsson K, Rönner U, Borch E. Inactivation of Escherichia coli, Listeria innocua and Saccharomyces cerevisiae in relation to membrane permeabilization and subsequent leakage of intracellular compounds due to pulsed electric field processing. Int J Food Microbiol 2005; 99:19-32. [PMID: 15718026 DOI: 10.1016/j.ijfoodmicro.2004.07.012] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2003] [Revised: 07/12/2004] [Accepted: 07/29/2004] [Indexed: 11/17/2022]
Abstract
Membrane permeabilization, caused by pulsed electric field (PEF) processing of microbial cells, was investigated by measurement of propidium iodide (PI) uptake with flow cytometry. Inactivation of Escherichia coli, Listeria innocua and Saccharomyces cerevisiae was determined by viable counts, and leakage of intracellular compounds, such as ATP and UV-absorbing substances, was measured in the extracellular environment. Electrical field strength and pulse duration influenced membrane permeabilization of all three tested organisms of which S. cerevisiae was the most PEF sensitive, followed by E. coli and L. innocua. It was shown by viable counts, PI uptake and leakage of intracellular compounds that L. innocua was the most resistant. Increased inactivation corresponded to greater numbers of permeabilized cells, which were reflected by increased PI uptake and larger amounts of intracellular compounds leaking from cells. For E. coli and L. innocua, a linear relationship was observed between the number of inactivated cells (determined as CFU) and cells with permeated membranes (determined by PI uptake), with higher number of inactivated cells than permeated cells. Increased leakage of intracellular compounds with increasing treatment severity provided further evidence that cells were permeabilized. For S. cerevisiae, there was higher PI uptake after PEF treatments, although very little or no inactivation was observed. Results suggest that E. coli and L. innocua cells, which took up PI, lost their ability to multiply, whereas cells of S. cerevisiae, which also took up PI, were not necessarily lethally permeabilized.
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Affiliation(s)
- Kristina Aronsson
- SIK, The Swedish Institute for Food and Biotechnology, PO Box 5401, SE-402 29 Göteborg, Sweden
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Chung YK, Vurma M, Turek EJ, Chism GW, Yousef AE. Inactivation of barotolerant Listeria monocytogenes in sausage by combination of high-pressure processing and food-grade additives. J Food Prot 2005; 68:744-50. [PMID: 15830665 DOI: 10.4315/0362-028x-68.4.744] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Food-grade additives were used to enhance the efficacy of high-pressure processing (HPP) against barotolerant Listeria monocytogenes. Three strains of L. monocytogenes (Scott A, OSY-8578, and OSY-328) were compared for their sensitivity to HPP, nisin, tert-butylhydroquinone (TBHQ), and their combination. Inactivation of these strains was evaluated in 0.2 M sodium phosphate buffer (pH 7.0) and commercially sterile sausage. A cell suspension of L. monocytogenes in buffer (10(9) CFU/ml) was treated with TBHQ at 100 ppm, nisin at 100 IU/ml, HPP at 400 MPa for 5 min, and combinations of these treatments. Populations of strains Scott A, OSY-8578, and OSY-328 decreased 3.9, 2.7, and 1.3 log with HPP alone and 6.4, 5.2, and 1.9 log with the HPP-TBHQ combination, respectively. Commercially sterile sausage was inoculated with the three L. monocytogenes strains (10(6) to 10(7) CFU/g) and treated with selected combinations of TBHQ (100 to 300 ppm), nisin (100 and 200 ppm), and HPP (600 MPa, 28 degrees C, 5 min). Samples were enriched to detect the viability of the pathogen after the treatments. Most of the samples treated with nisin, TBHQ, or their combination were positive for L. monocytogenes. HPP alone resulted in a modest decrease in the number of positive samples. L. monocytogenes was not detected in any of the inoculated commercial sausage samples after treatment with HPP-TBHQ or HPP-TBHQ-nisin combinations. These results suggest that addition of TBHQ or TBHQ plus nisin to sausage followed by in-package pressurization is a promising method for producing Listeria-free ready-to-eat products.
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Affiliation(s)
- Yoon-Kyung Chung
- Department of Food Science and Technology, Ohio State University, Columbus, Ohio 43210, USA
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Lado BH, Bomser JA, Dunne CP, Yousef AE. Pulsed electric field alters molecular chaperone expression and sensitizes Listeria monocytogenes to heat. Appl Environ Microbiol 2004; 70:2289-95. [PMID: 15066824 PMCID: PMC383135 DOI: 10.1128/aem.70.4.2289-2295.2004] [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: 09/08/2003] [Accepted: 01/12/2004] [Indexed: 11/20/2022] Open
Abstract
Pulsed electric field (PEF)-resistant and PEF-sensitive Listeria monocytogenes strains were sublethally treated with electric pulses at 15 kV/cm for 29 micro s and held at 25 degrees C for 5 to 30 min prior to protein extraction. The levels of the molecular chaperones GroEL, GroES, and DnaJ were determined by immunoblotting. After 10 to 20 min after sublethal PEF treatment, a transient decrease in molecular chaperone expression was observed in the PEF-sensitive strain (Scott A). The levels of GroEL and DnaJ increased back to the basal expression level within 30 min. A substantial decrease in GroES expression persisted for at least 30 min after PEF treatment. Chaperone expression was suppressed after PEF treatment to a smaller extent in the PEF-resistant (OSY-8578) than in the PEF-sensitive strain, and no clear expression pattern was identified in OSY-8578. Inactivation of Scott A and OSY-8578 in phosphate buffer was compared when lethal PEF (27.5 kV/cm, 144 micro s) and heat (55 degrees C, 10 min) were applied in sequence. When PEF and heat treatments were applied separately, the populations of L. monocytogenes Scott A and OSY-8578 decreased 0.5 to 0.6 log CFU/ml. Cells treated first with PEF and incubated at 25 degrees C for 10 min showed substantial sensitivity to subsequent heat treatment; the decrease in counts for Scott A and OSY-8578 was 6.1 and 2.8 log CFU/ml, respectively. The sequence and time lapse between the two treatments were crucial for achieving high inactivation rates. It is concluded that PEF sensitized L. monocytogenes to heat and that maximum heat sensitization occurred when chaperone expression was at a minimum level.
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Affiliation(s)
- Beatrice H Lado
- Department of Food Science and Technology, The Ohio State University, Columbus, Ohio 43210, USA
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