1
|
Yang D, Jiang Z, Meng Q, Wang S, Pan H, Rao L, Liao X. Analyzing the pressure resistant, sublethal injury and resuscitable viable but non-culturable state population of Escherichia coli, Staphylococcus aureus, Bacillus amyloliquefaciens and Lactiplantibacillus plantarum under high pressure processing. Food Res Int 2023; 173:113336. [PMID: 37803646 DOI: 10.1016/j.foodres.2023.113336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/26/2023] [Accepted: 07/29/2023] [Indexed: 10/08/2023]
Abstract
This study aimed to analyze and reduce the pressure resistance (PR), sublethal injury (SLI), and viable but non-culturable (VBNC) populations during HPP. Escherichia coli, Staphylococcus aureus, Bacillus amyloliquefaciens and Lactiplantibacillus plantarum were selected for evaluation of PR, SLI and VBNC cell counts and proportions during HPP. The results revealed that the bactericidal efficiency against these strains gradually improved as the processing pressure increased. However, viable bacteria could still be detected, suggesting that there may involve the presence of resistant population that difficult to be killed or revived from SLI. Further detecting the quantity and proportion of PR, SLI and VBNC bacteria found that these state of cells were present during whole HPP treatment. Additionally, the more resistant a bacterial species was to high pressure, the fewer SLI and more resuscitable VBNC (RVBNC) populations it generated, and vice versa. Therefore, correlation analysis was also employed to make the relationship between log reduction, SLI and RVBNC population ratios clearer. The results demonstrated that the log reduction was highly positive correlation with SLI population ratios, and negative correlation with RVBNC population within our detected species at 500 MPa. Furthermore, CO2 and Nisin were employed to combined with HPP to reduce these survivors. Comparing with 233, 218, 241 and 259 MPa for HPP treatment, it took 37, 89, 135 and 229 MPa for HPP + CO2, and 189, 161, 199 and 292 MPa for HPP + Nisin to the first decimal reduction for E. coli, S.aureus, B. amyloliquefaciens and L. plantarum, respectively. The results indicated that HPP combined with CO2 or Nisin could significantly reduce the quantity of PR, SLI, and RVBNC cells during HPP, and provide better bactericidal effects. In conclusion, we quantified the presence of PR, SLI, and VBNC bacteria after high pressure treatment and investigate the effectiveness of HPP combined with CO2 or Nisin to enhance the inactivation of bacteria and reduce the occurrence of PR, SLI, and RVBNC bacteria.
Collapse
Affiliation(s)
- Dong Yang
- College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-thermal Processing, Beijing 100083, PR China
| | - Zhidong Jiang
- College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-thermal Processing, Beijing 100083, PR China
| | - Qiuyu Meng
- College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-thermal Processing, Beijing 100083, PR China
| | - Shengkang Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-thermal Processing, Beijing 100083, PR China
| | - Hanxu Pan
- School of Light Industry, Beijing Technology and Business University, Beijing 100048, PR China
| | - Lei Rao
- College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-thermal Processing, Beijing 100083, PR China
| | - Xiaojun Liao
- College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-thermal Processing, Beijing 100083, PR China.
| |
Collapse
|
2
|
Lee EJ, Kim SH, Park SH. Effect of high hydrostatic pressure treatment on the inactivation and sublethal injury of foodborne pathogens and quality of apple puree at different pH. Food Microbiol 2023; 114:104302. [PMID: 37290878 DOI: 10.1016/j.fm.2023.104302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 04/28/2023] [Accepted: 04/28/2023] [Indexed: 06/10/2023]
Abstract
The objectives of this study were to evaluate the survival of high hydrostatic pressure (HHP)-treated Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes in apple puree, as well as to determine the levels of HHP-induced cell injury according to the pressure level, holding time, and pH of apple puree. Apple puree was inoculated with three foodborne pathogens and treated at pressures of 300-600 MPa for up to 7 min at 22 °C using HHP equipment. Increasing the pressure level and lowering the pH of apple puree led to larger microbial reductions, and E. coli O157:H7 showed higher resistance compared to S. Typhimurium and L. monocytogenes. Besides, approximately 5-log injured cells of E. coli O157:H7 were induced in apple puree at pH 3.5 and 3.8. HHP treatment at 500 MPa for 2 min effectively achieved complete inactivation of the three pathogens in apple puree at pH 3.5. For apple puree at pH 3.8, more than 2 min treatment of HHP at 600 MPa is seemingly needed to achieve complete inactivation of the three pathogens. Transmission electron microscopy analysis was conducted to identify ultrastructural changes in the injured or dead cells after HHP treatment. Plasmolysis and uneven cavities in the cytoplasm were observed in injured cells, and additional deformations, such as distorted and rough cell envelopes, and cell disruption occurred in dead cells. No changes in solid soluble content (SSC) and color of apple puree were observed after HHP treatment, and no differences were detected between control and HHP-treated samples during 10 d of storage at 5 °C. The results of this study could be useful in determining the acidity of apple purees or the treatment time at specific acidity levels when applying the HHP processing.
Collapse
Affiliation(s)
- Eun-Jung Lee
- Department of Food Science and Technology, Kongju National University, Yesan, Chungnam, 32439, Republic of Korea
| | - Soo-Hwan Kim
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Food and Bioconvergence and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Sang-Hyun Park
- Department of Food Science and Technology, Kongju National University, Yesan, Chungnam, 32439, Republic of Korea.
| |
Collapse
|
3
|
Shao L, Sun Y, Zou B, Zhao Y, Li X, Dai R. Sublethally injured microorganisms in food processing and preservation: Quantification, formation, detection, resuscitation and adaption. Food Res Int 2023; 165:112536. [PMID: 36869540 DOI: 10.1016/j.foodres.2023.112536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/14/2023] [Accepted: 01/21/2023] [Indexed: 01/29/2023]
Abstract
Sublethally injured state has been recognized as a survival strategy for microorganisms suffering from stressful environments. Injured cells fail to grow on selective media but can normally grow on nonselective media. Numerous microorganism species can form sublethal injury in various food matrices during processing and preservation with different techniques. Injury rate was commonly used to evaluate sublethal injury, but mathematical models for the quantification and interpretation of sublethally injured microbial cells still require further study. Injured cells can repair themselves and regain viability on selective media under favorable conditions when stress is removed. Conventional culture methods might underestimate microbial counts or present a false negative result due to the presence of injured cells. Although the structural and functional components may be affected, the injured cells pose a great threat to food safety. This work comprehensively reviewed the quantification, formation, detection, resuscitation and adaption of sublethally injured microbial cells. Food processing techniques, microbial species, strains and food matrix all significantly affect the formation of sublethally injured cells. Culture-based methods, molecular biological methods, fluorescent staining and infrared spectroscopy have been developed to detect the injured cells. Cell membrane is often repaired first during resuscitation of injured cells, meanwhile, temperature, pH, media and additives remarkably influence the resuscitation. The adaption of injured cells negatively affects the microbial inactivation during food processing.
Collapse
Affiliation(s)
- Lele Shao
- Beijing Higher Institution Engineering Research Center of Animal Product, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Yingying Sun
- Beijing Higher Institution Engineering Research Center of Animal Product, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Bo Zou
- Beijing Higher Institution Engineering Research Center of Animal Product, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Yijie Zhao
- Beijing Higher Institution Engineering Research Center of Animal Product, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Xingmin Li
- Beijing Higher Institution Engineering Research Center of Animal Product, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Ruitong Dai
- Beijing Higher Institution Engineering Research Center of Animal Product, College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China.
| |
Collapse
|
4
|
Lan L, Shi H. New insights into the formation and recovery of sublethally injured Escherichia coli O157:H7 induced by lactic acid. Food Microbiol 2022; 102:103918. [PMID: 34809944 DOI: 10.1016/j.fm.2021.103918] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 08/19/2021] [Accepted: 09/26/2021] [Indexed: 11/21/2022]
Abstract
Escherichia coli O157:H7 can be injured by the action of lactic acid (LA) and injured cells can be recovered under suitable condition. In this study, RNA sequencing analysis revealed the overall genes change of sublethally injured (4 mM LA, 60 min; SI) and initial recovered (minA, 20 min; R) cells. Compared with untreated samples, 53 up-regulated and 98 down-regulated differentially expressed genes (DEGs; Padj < 0.05, change fold ≥2) were found in SI. Meanwhile, Genes related to carbohydrate transport and metabolic were up-regulated and the addition of carbohydrate increased cells resistance to LA. Genes involved in osmotic stress response and cell membrane integrity were down-regulated and E. coli O157:H7 cells were sensitive to osmotic stress during sublethal injury. Genes related to iron stress response and cation transport were changed and cation may affect sublethal injury formation by influencing production of ROS and cellular processes. In R, 1370 up-regulated and 1110 down-regulated DEGs were subdivided into various GO terms and membrane, biological adhesion, cell projection, oxidation-reduction process and catalytic activity, etc., showed significant enrichment (corrected P < 0.05). Particularly, genes related to fimbrial, flagellum and type III secretion system were up-regulated, which may improve infection ability and virulence property during recovery of injured cells. These findings provide novel insights into formation and recovery of sublethally injured E. coli O157:H7 induced by LA.
Collapse
|
5
|
Shao L, Zhao Y, Zou B, Li X, Dai R. Recovery and virulence factors of sublethally injured Staphylococcus aureus after ohmic heating. Food Microbiol 2022; 102:103899. [PMID: 34809931 DOI: 10.1016/j.fm.2021.103899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/20/2021] [Accepted: 09/09/2021] [Indexed: 11/22/2022]
Abstract
Ohmic heating (OH) is an alternative thermal processing technique, which is widely used to pasteurize or sterilize food. However, sublethally injured Staphylococcus aureus induced by OH is a great concern to food safety. The recovery of injured S. aureus by OH and virulence factor changes during recovery were investigated in this study. The liquid media (phosphate-buffered saline, buffered peptone water and nutrient broth (NB)), temperature (4, 25 and 37 °C) and pH (6.0, 7.2 and 8.0) influenced the recovery rate and the injured cells completely repaired in NB at 37 °C, pH 7.2 with the shortest time of 2 h. The biofilm formation ability, mannitol fermentation, hemolysis, and coagulase activities decreased in injured S. aureus and recovered during repair process. Quantitative real-time PCR showed the expression of sek, clfB and lukH involved in virulence factors increased during recovery. The results indicated that the virulence factors of injured S. aureus recovered after repair.
Collapse
|
6
|
Chuang S, Sheen S, Sommers CH, Zhou S, Sheen LY. Survival Evaluation of Salmonella and Listeria monocytogenes on Selective and Nonselective Media in Ground Chicken Meat Subjected to High Hydrostatic Pressure and Carvacrol. J Food Prot 2020; 83:37-44. [PMID: 31809196 DOI: 10.4315/0362-028x.jfp-19-075] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
High pressure processing (HPP) and treatment with the essential oil extract carvacrol had synergistic inactivation effects on Salmonella and Listeria monocytogenes in fresh ground chicken meat. Seven days after HPP treatment at 350 MPa for 10 min, Salmonella treated with 0.75% carvacrol was reduced to below the detection limit (1 log CFU/g) at 4°C and was reduced by ca. 6 log CFU at 10°C. L. monocytogenes was more sensitive to these imposed stressors, remaining below the detection limit during storage at both 4 and 10°C after HPP treatment at 350 MPa for 10 min following treatment with 0.45% carvacrol. However, pressure-injured bacterial cells may recover and lead to an overestimation of process lethality when a selective medium is used without proper justification. For HPP-stressed Salmonella, a 1- to 2-log difference was found between viable counts on xylose lysine Tergitol 4 agar and aerobic plate counts, but no significant difference was found for HPP-stressed L. monocytogenes between polymyxin-acriflavine-lithium chloride-ceftazidime-esculin-mannitol (PALCAM) agar and aerobic plate counts. HPP-induced bacterial injury and its recovery have been investigated by comparing selective and nonselective agar plate counts; however, few investigations have addressed this issue in the presence of essential oil extracts, taking into account the effect of high pressure and natural antimicrobial compounds (e.g., carvacrol) on bacterial survival in various growth media. Use of selective media may overestimate the efficacy of bacterial inactivation in food processing evaluation and validation studies, and the effects of various media should be systematically investigated.
Collapse
Affiliation(s)
- Shihyu Chuang
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania 19038, USA.,Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Shiowshuh Sheen
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania 19038, USA
| | - Christopher H Sommers
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania 19038, USA
| | - Siyuan Zhou
- College of Food Science, Southwest University, Chongqing 400715, People's Republic of China
| | - Lee-Yan Sheen
- Institute of Food Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| |
Collapse
|
7
|
Tian X, Shao L, Yu Q, Yang H, Li X, Dai R. Comparative study of survival of Escherichia coli O157:H7 inoculated in pork batter after ohmic cooking and water bath cooking. Int J Food Microbiol 2019; 304:11-18. [PMID: 31146053 DOI: 10.1016/j.ijfoodmicro.2019.05.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/15/2019] [Accepted: 05/22/2019] [Indexed: 01/16/2023]
Abstract
In this study, the effects of ohmic cooking (OH) and water bath cooking (WB) on the reduction of Escherichia coli O157:H7 inoculated in pork batter with addition of sodium chloride (NaCl) were studied, and the recovery and growth of OH and WB treated E. coli O157:H7 were also investigated during storage. The time for samples cooked by OH to reach the targeted endpoint temperature (61, 65, and 72 °C) was shorter than that of WB, and the addition of NaCl dramatically shortened the cooking time of OH treated samples, however, no significant effect was observed by WB. Samples with NaCl and cooked by OH had lower cooking loss than that of WB, but the inactivation effect of E. coli O157:H7 by OH was comparable to WB. During storage, the recovery and growth of sublethally injured E. coli O157:H7 were slower at 4 °C, and storage at 4 °C for 24 h delayed their recovery at 37 °C from 36 h to 48 h. These results indicated that OH had greater potential in the application of meat batter processing.
Collapse
Affiliation(s)
- Xiaojing Tian
- College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, PR China; Beijing Higher Institution Engineering Research Center of Animal Product, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Lele Shao
- College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, PR China; Beijing Higher Institution Engineering Research Center of Animal Product, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Qianqian Yu
- College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, PR China; Beijing Higher Institution Engineering Research Center of Animal Product, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Huan Yang
- College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, PR China; Beijing Higher Institution Engineering Research Center of Animal Product, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Xingmin Li
- College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, PR China; Beijing Higher Institution Engineering Research Center of Animal Product, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China
| | - Ruitong Dai
- College of Food Science and Nutritional Engineering, China Agricultural University, No.17 Qinghua East Road, Haidian District, Beijing 100083, PR China; Beijing Higher Institution Engineering Research Center of Animal Product, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing 100083, PR China.
| |
Collapse
|
8
|
Marcén M, Cebrián G, Ruiz-Artiga V, Condón S, Mañas P. Cellular events involved in E. coli cells inactivation by several agents for food preservation: A comparative study. Food Microbiol 2019; 84:103246. [PMID: 31421746 DOI: 10.1016/j.fm.2019.103246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/16/2019] [Accepted: 06/18/2019] [Indexed: 12/14/2022]
Abstract
Traditional and novel technologies for food preservation are being investigated to obtain safer products and fulfil consumer demands for less processed foods. These technologies inactivate microorganisms present in foods through their action on different cellular targets, but the final cause of cell loss of viability often remains not well characterized. The main objective of this work was to study and compare cellular events that could play a role on E. coli inactivation upon exposure to treatments with technologies of different nature. E. coli cells were exposed to heat, high hydrostatic pressure (HHP), pulsed electric fields (PEF) and acid treatments, and the occurrence of several alterations, including presence of sublethal injury, membrane permeabilization, increased levels of reactive oxygen species (ROS), DNA damage and protein damage were studied. Results reflected differences among the relevance of the several cellular events depending on the agent applied. Sublethally injured cells appeared after all the treatments. Cells consistently recovered in a higher percentage in non-selective medium, particularly in minimal medium, as compared to selective medium; however this effect was less relevant in PEF-treated cells. Increased levels of ROS were detected inside cells after all the treatments, although their order of appearance and relationship with membrane permeabilization varied depending on the technology. A high degree of membrane permeabilization was observed in PEF treated cells, DNA damage appeared as an important target in acid treatment, and protein damage, in HHP treated cells. Results obtained help to understand the mode of action of food preservation technologies on bacterial cells.
Collapse
Affiliation(s)
- María Marcén
- Tecnología de los Alimentos, Facultad de Veterinaria de Zaragoza, Instituto Agroalimentario de Aragón- IA2 - (Universidad de Zaragoza-CITA), Zaragoza, Spain
| | - Guillermo Cebrián
- Tecnología de los Alimentos, Facultad de Veterinaria de Zaragoza, Instituto Agroalimentario de Aragón- IA2 - (Universidad de Zaragoza-CITA), Zaragoza, Spain
| | - Virginia Ruiz-Artiga
- Tecnología de los Alimentos, Facultad de Veterinaria de Zaragoza, Instituto Agroalimentario de Aragón- IA2 - (Universidad de Zaragoza-CITA), Zaragoza, Spain
| | - Santiago Condón
- Tecnología de los Alimentos, Facultad de Veterinaria de Zaragoza, Instituto Agroalimentario de Aragón- IA2 - (Universidad de Zaragoza-CITA), Zaragoza, Spain
| | - Pilar Mañas
- Tecnología de los Alimentos, Facultad de Veterinaria de Zaragoza, Instituto Agroalimentario de Aragón- IA2 - (Universidad de Zaragoza-CITA), Zaragoza, Spain.
| |
Collapse
|
9
|
Bi X, Wang Y, Hu X, Liao X. Decreased resistance of sublethally injured Escherichia coli O157:H7 to salt, mild heat, nisin and acids induced by high pressure carbon dioxide. Int J Food Microbiol 2018; 269:137-143. [PMID: 29427854 DOI: 10.1016/j.ijfoodmicro.2018.01.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 12/28/2017] [Accepted: 01/30/2018] [Indexed: 11/18/2022]
Abstract
Resistance of sublethally injured cells (SICs) of Escherichia coli O157:H7 induced by high pressure carbon dioxide (HPCD) to salt, low temperature, mild heat, nisin, acids and low pHs was investigated in this study. The SICs of E. coli were obtained following HPCD at 5 MPa and 25 °C for 40-60 min or 5 MPa and 45 °C for 20 min. The untreated cells could survive normally while the HPCD-treated cells showed 2.87 log10 cycles' reduction on tryptic soy agar (TSA) with 3% NaCl. The counts of the untreated cells were not significantly changed during 5 h incubation at 4 °C or 40 min incubation at 45 °C, and the HPCD-treated cells were also not affected by 5 h incubation at 4 °C but showed 1.75 log10 cycles' reduction at 45 °C for 40 min. The antimicrobial nisin caused an extra 0.25-1.0 log10 cycles' reduction of the HPCD-treated cells while the untreated cells was not inactivated by nisin. Except for oxalic acid (OA), citric acid (CA), malic acid (MA), tartaric acid (TA), lactic acid (LA), acetic acid (AA) and hydrochloric acid (HCl) did not inactivate the untreated cells, but all these seven acids caused a 0.74-1.53 log10 cycles' reduction of HPCD-treated cells. These results indicated that HPCD-induced SICs had a decreased resistance to salt, mild heat, nisin and acids. Moreover, the recovery test was used to investigate the sensitivity of the SICs to different pHs. Results showed that the SICs could not recover below or equal to pH 4.0. These promising results would open up the possibility of exploring the combination of other technologies (eg. mild heat, nisin and acids) with HPCD as hurdle approaches to inactivate target pathogens in foods.
Collapse
Affiliation(s)
- Xiufang Bi
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; Key Lab of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing, China; Sichuan Key Laboratory of Food Bio-technology, College of Food and Bioengineering, Xihua University, Chengdu, China
| | - Yongtao Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; Key Lab of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing, China
| | - Xiaosong Hu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; Key Lab of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing, China
| | - Xiaojun Liao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China; Key Lab of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing, China.
| |
Collapse
|
10
|
Li J, Suo Y, Liao X, Ahn J, Liu D, Chen S, Ye X, Ding T. Analysis of Staphylococcus aureus cell viability, sublethal injury and death induced by synergistic combination of ultrasound and mild heat. Ultrason Sonochem 2017; 39:101-110. [PMID: 28732925 DOI: 10.1016/j.ultsonch.2017.04.019] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 04/13/2017] [Accepted: 04/13/2017] [Indexed: 05/19/2023]
Abstract
This study was designed to investigate the combined effects of ultrasound and mild heat on the viability of S. aureus in association with the cell membrane integrity and intracellular enzyme activity. Cells were treated by ultrasound under 55°C for 3, 5, 7, 10, and 15min. The dynamic changes of S. aureus cell viability, sublethal injury and death were evaluated using flow cytometric assay. Microscopies were applied to identify the morphological appearance, ultrastructure and topography of S. aureus. The results showed the membrane damage was synchronous with esterase inhibition during the exposure to sonication, leading to the immediate lethal effect. On the other hand, bacteria under the mild heat at 55°C were inactivated via a sublethal injury process. The different lethal modes were observed between sonication and mild heat treatments, which could synergistically inactivate S. aureus. The antibacterial value of thermo-sonication was greater than the sum of the individual treatments. The thermo-sonication combination synergistically reduced the number of sublethal cells and also resulted in severe cell damage.
Collapse
Affiliation(s)
- Jiao Li
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yuanjie Suo
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xinyu Liao
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Juhee Ahn
- Department of Medical Biomaterials Engineering, Kangwon National University, Gangwon, Chuncheon, Republic of Korea
| | - Donghong Liu
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shiguo Chen
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xingqian Ye
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China
| | - Tian Ding
- Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang, China.
| |
Collapse
|
11
|
Liao X, Xiang Q, Liu D, Chen S, Ye X, Ding T. Lethal and Sublethal Effect of a Dielectric Barrier Discharge Atmospheric Cold Plasma on Staphylococcus aureus. J Food Prot 2017; 80:928-932. [PMID: 28459615 DOI: 10.4315/0362-028x.jfp-16-499] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The lethal and sublethal effect of a dielectric barrier discharge atmospheric cold plasma on Staphylococcus aureus were investigated by nonselective and selective media. The inactivation level and sublethally injured proportions of S. aureus cells by dielectric barrier discharge atmospheric cold plasma depended on the treatment times (0, 5, 15, and 45 s), applied input powers (40, 50, and 60 W), and gap distances (2, 4, and 6 mm). Under weak conditions (e.g., 5 s, 40 W, and 6 mm), the occurrence of inactivation and sublethal injury of S. aureus showed a relatively low level. Strong treatment (e.g., 45 s, 60 W, and 2 mm) resulted in highly an inactivated rate, but with small fractions of sublethally injured S. aureus cells. Mild action of cold plasma induced both a large inactivation and a sublethal injury of S. aureus . Therefore, it is significant to optimize the processing of cold plasma sterilization in practice to ensure food safety.
Collapse
Affiliation(s)
- Xinyu Liao
- 1 Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Qisen Xiang
- 2 College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, People's Republic of China
| | - Donghong Liu
- 1 Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Shiguo Chen
- 1 Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Xingqian Ye
- 1 Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| | - Tian Ding
- 1 Department of Food Science and Nutrition, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang University, Hangzhou, Zhejiang 310058, People's Republic of China
| |
Collapse
|
12
|
Noriega E, Velliou EG, Van Derlinden E, Mertens L, Van Impe JFM. Role of growth morphology in the formulation of NaCl-based selective media for injury detection of Escherichia coli, Salmonella Typhimurium and Listeria innocua. Food Res Int 2014; 64:402-411. [PMID: 30011667 DOI: 10.1016/j.foodres.2014.06.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/26/2014] [Accepted: 06/29/2014] [Indexed: 11/26/2022]
Abstract
Sublethal injury (SI) poses major public health concerns since injured cells are responsible for serious limitations in food diagnostics and are susceptible to recovery, often developing adaptive stress responses. Detection of SI is based on the difference in plate counts between non-selective media, which represent the total cell population, and selective media, to which injured cells become sensitive. Selective media for detection of sublethal membrane damage are often based on NaCl supplement, although there is a lack of consensus in the literature about appropriate levels. Planktonic cells are generally used to investigate SI mechanisms, although they often exhibit different stress tolerance than cell colonies in/on solid food (model) systems. In this work, the effect of growth morphology, colony size and concentration of the gelling agent in the growth media, on the maximum non-inhibitory NaCl concentration in the plating medium was assessed for Escherichia coli, Salmonella Typhimurium and Listeria innocua. Stationary phase cultures of planktonic cells and large and small colonies grown in either 1.5% (w/v) xanthan gum-based system or 2.5% (w/v) xanthan gum-based system exhibited significantly different viable counts and osmotolerance. The effect of cell arrangement and xanthan gum percentage in the growth media depended on the microorganism under investigation. Additionally, differences in the maximum non-inhibitory concentration were evident, with 5.0% (w/v) NaCl for the Gram-negative bacteria and 6.5% (w/v), for L. innocua. Different extent of colony shrinkage and morphological damage was observed as NaCl concentration in the plating medium increased. This information will contribute to define NaCl-based selective media for accurate SI detection under realistic scenarios.
Collapse
Affiliation(s)
- Estefanía Noriega
- CPMF(2) - Flemish Cluster Predictive Microbiology in Foods, http://www.cpmf2.be, Belgium; BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Leuven, Belgium.
| | - Eirini G Velliou
- CPMF(2) - Flemish Cluster Predictive Microbiology in Foods, http://www.cpmf2.be, Belgium; BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Leuven, Belgium.
| | - Eva Van Derlinden
- CPMF(2) - Flemish Cluster Predictive Microbiology in Foods, http://www.cpmf2.be, Belgium; BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Leuven, Belgium.
| | - Laurence Mertens
- CPMF(2) - Flemish Cluster Predictive Microbiology in Foods, http://www.cpmf2.be, Belgium; BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Leuven, Belgium.
| | - Jan F M Van Impe
- CPMF(2) - Flemish Cluster Predictive Microbiology in Foods, http://www.cpmf2.be, Belgium; BioTeC - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Leuven, Belgium.
| |
Collapse
|
13
|
Noriega E, Velliou E, Van Derlinden E, Mertens L, Van Impe JFM. Effect of cell immobilization on heat-induced sublethal injury of Escherichia coli, Salmonella Typhimurium and Listeria innocua. Food Microbiol 2013; 36:355-64. [PMID: 24010617 DOI: 10.1016/j.fm.2013.06.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 05/15/2013] [Accepted: 06/14/2013] [Indexed: 10/26/2022]
Abstract
The occurrence of sublethally injured cells in foods poses major public health concerns and is an essential aspect when assessing the microbial response to food preservation strategies, yet there is limited research dealing with its specific implications for mild heating. All available studies so far have been performed in broths colonized by planktonic cells, although their susceptibility to lethal agents has often been reported to be markedly different to the stress tolerance of cell colonies developed in solid foods. In this work, the effect of planktonic and colony growth, as well as the influence of colony density on sublethal injury induced by mild heating of Escherichia coli, Salmonella Typhimurium and Listeria innocua were assessed in food model systems. Detection of injured survivors relied on their inability to form visible colonies on salt-based selective media, which do not affect the growth of healthy cells. Sublethal injury (SI) increased rapidly with shorter exposure times and afterwards, decreased progressively, suggesting a mechanism of cumulative damage triggering lethal instead of SI. Cell arrangement affected the degree of SI, higher values being generally found for gelified systems, although the effect of colony density depended on the target microorganism. This information is essential for optimizing the design of food safety assurance systems.
Collapse
|