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Bolten S, Belias A, Weigand KA, Pajor M, Qian C, Ivanek R, Wiedmann M. Population dynamics of Listeria spp., Salmonella spp., and Escherichia coli on fresh produce: A scoping review. Compr Rev Food Sci Food Saf 2023; 22:4537-4572. [PMID: 37942966 DOI: 10.1111/1541-4337.13233] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 08/05/2023] [Accepted: 08/10/2023] [Indexed: 11/10/2023]
Abstract
Collation of the current scope of literature related to population dynamics (i.e., growth, die-off, survival) of foodborne pathogens on fresh produce can aid in informing future research directions and help stakeholders identify relevant research literature. A scoping review was conducted to gather and synthesize literature that investigates population dynamics of pathogenic and non-pathogenic Listeria spp., Salmonella spp., and Escherichia coli on whole unprocessed fresh produce (defined as produce not having undergone chopping, cutting, homogenization, irradiation, or pasteurization). Literature sources were identified using an exhaustive search of research and industry reports published prior to September 23, 2021, followed by screening for relevance based on strict, a priori eligibility criteria. A total of 277 studies that met all eligibility criteria were subjected to an in-depth qualitative review of various factors (e.g., produce commodities, study settings, inoculation methodologies) that affect population dynamics. Included studies represent investigations of population dynamics on produce before (i.e., pre-harvest; n = 143) and after (i.e., post-harvest; n = 144) harvest. Several knowledge gaps were identified, including the limited representation of (i) pre-harvest studies that investigated population dynamics of Listeria spp. on produce (n = 13, 9% of pre-harvest studies), (ii) pre-harvest studies that were carried out on non-sprouts produce types grown using hydroponic cultivation practices (n = 7, 5% of pre-harvest studies), and (iii) post-harvest studies that reported the relative humidity conditions under which experiments were carried out (n = 56, 39% of post-harvest studies). These and other knowledge gaps summarized in this scoping review represent areas of research that can be investigated in future studies.
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Affiliation(s)
- Samantha Bolten
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Alexandra Belias
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Kelly A Weigand
- Cary Veterinary Medical Library, Auburn University, Auburn, Alabama, USA
- Flower-Sprecher Veterinary Library, Cornell University, Ithaca, New York, USA
| | - Magdalena Pajor
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Chenhao Qian
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Renata Ivanek
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, New York, USA
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Koutsoumanis K, Ordóñez AA, Bolton D, Bover‐Cid S, Chemaly M, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Nonno R, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Banach J, Ottoson J, Zhou B, da Silva Felício MT, Jacxsens L, Martins JL, Messens W, Allende A. Microbiological hazards associated with the use of water in the post-harvest handling and processing operations of fresh and frozen fruits, vegetables and herbs (ffFVHs). Part 1 (outbreak data analysis, literature review and stakeholder questionnaire). EFSA J 2023; 21:e08332. [PMID: 37928944 PMCID: PMC10623241 DOI: 10.2903/j.efsa.2023.8332] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2023] Open
Abstract
The contamination of water used in post-harvest handling and processing operations of fresh and frozen fruit, vegetables and herbs (ffFVHs) is a global concern. The most relevant microbial hazards associated with this water are: Listeria monocytogenes, Salmonella spp., human pathogenic Escherichia coli and enteric viruses, which have been linked to multiple outbreaks associated with ffFVHs in the European Union (EU). Contamination (i.e. the accumulation of microbiological hazards) of the process water during post-harvest handling and processing operations is affected by several factors including: the type and contamination of the FVHs being processed, duration of the operation and transfer of microorganisms from the product to the water and vice versa, etc. For food business operators (FBOp), it is important to maintain the microbiological quality of the process water to assure the safety of ffFVHs. Good manufacturing practices (GMP) and good hygienic practices (GHP) related to a water management plan and the implementation of a water management system are critical to maintain the microbiological quality of the process water. Identified hygienic practices include technical maintenance of infrastructure, training of staff and cooling of post-harvest process water. Intervention strategies (e.g. use of water disinfection treatments and water replenishment) have been suggested to maintain the microbiological quality of process water. Chlorine-based disinfectants and peroxyacetic acid have been reported as common water disinfection treatments. However, given current practices in the EU, evidence of their efficacy under industrial conditions is only available for chlorine-based disinfectants. The use of water disinfection treatments must be undertaken following an appropriate water management strategy including validation, operational monitoring and verification. During operational monitoring, real-time information on process parameters related to the process and product, as well as the water and water disinfection treatment(s) are necessary. More specific guidance for FBOp on the validation, operational monitoring and verification is needed.
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Wang Y, Chen Z, Zhao F, Yang H. Metabolome shifts triggered by chlorine sanitisation induce Escherichia coli on fresh produce into the viable but nonculturable state. Food Res Int 2023; 171:113084. [PMID: 37330837 DOI: 10.1016/j.foodres.2023.113084] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 06/19/2023]
Abstract
Facing the increasing occurrence of "big six" Escherichia coli outbreaks linked to fresh produce, chlorine-based sanitisers are widely used for fresh produce decontamination in recent years. However, latest finding that chlorine may induce E. coli cells into a viable not nonculturable (VBNC) state is bringing a new challenge to the fresh produce industry. VBNC cells are undetectable by the plate count test, and yet they retain pathogenicity and are more antibiotic-resistant than culturable cells. As a result, their eradication is critical to ensure the safety of fresh produce. Understanding VBNC cells at the metabolic level may provide a breakthrough for their eradication. Therefore, this study was carried out to collect the VBNC pathogenic E. coli (O26:H11, O121:H19, and O157:H7) cells from chlorine-treated pea sprouts and characterise them using NMR-based metabolomics. From the globally increased metabolite contents detected in the VBNC E. coli cells as compared to the culturable cells, mechanisms underlying E. coli's VBNC induction were elucidated. These include rendering the energy generation scheme to become more compatible with the lowered energy needs, disaggregating protein aggregates to release amino acids for osmoprotection and later resuscitation, as well as increasing cAMP content to downregulate RpoS. These identified metabolic characteristics can inspire future development of targeted measures for VBNC E. coli cell inhibition. Our methods can also be applied to other pathogens to help lower the risk of overall foodborne diseases.
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Affiliation(s)
- Yue Wang
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore.
| | - Zihui Chen
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore
| | - Fengnian Zhao
- Department of Food Science and Technology, National University of Singapore, Singapore 117542, Singapore
| | - Hongshun Yang
- Shaoxing Key Laboratory of Traditional Fermentation Food and Human Health, Jiangnan University (Shaoxing) Industrial Technology Research Institute, Zhejiang, 312000, China.
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Truchado P, Gómez-Galindo M, Gil MI, Allende A. Cross-contamination of Escherichia coli O157:H7 and Listeria monocytogenes in the viable but non-culturable (VBNC) state during washing of leafy greens and the revival during shelf-life. Food Microbiol 2023; 109:104155. [PMID: 36309451 DOI: 10.1016/j.fm.2022.104155] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/22/2022] [Accepted: 10/02/2022] [Indexed: 03/14/2023]
Abstract
Some water disinfection treatments, such as chlorine and chlorine dioxide, used in the fresh-cut industry to maintain the microbiological quality of process water (PW), inactivate bacterial cells in the water but they also lead to the induction of an intermediate state between viable and non-viable known as viable but non-culturable (VBNC) state. Viable cells can participate in cross-contamination events but the significance of VBNC cells in PW, transfer to the product and potential resuscitation capacity during storage is unclear. The present study aims to determine first, if VBNC cells present in PW can cross-contaminate leafy greens during washing and secondly its potential revival during shelf-life. Process water characterized by a high chemical oxygen demand, due to the presence of high levels of organic matter, was inoculated with Listeria monocytogenes or Escherichia coli O157:H7. Inoculated PW was then treated for 1 min with chlorine dioxide (3 mg/L) or chlorine (5 mg/L) to generate VBNC cells. Absence of culturable cells was confirmed by plate count and VBNC cells by viability quantitative polymerase chain reaction (v-qPCR) complemented with two dyes, ethidium (EMA) and propidium (PMAxx) monoazide. Cross-contamination of shredded lettuce was demonstrated by monitoring the VBNC cells after washing the product for 1 min in the contaminated PW and during shelf life (15 days at 7 °C). In the case of L. monocytogenes, considering the total concentration of L. monocytogenes VBNC cells present in the PW, only a low proportion of cells were able to cross-contaminate the product during washing. VBNC L. monocytogenes cells were able to resuscitate on the product during shelf life, although levels of cultivable bacteria, close to the limit if detection (0.7 ± 0.0 log CFU/g), were only detected at the end of storage. On the other hand, VBNC cells of E. coli O157:H7 present in PW were not able to cross-contaminate shredded lettuce during washing. Moreover, when shredded lettuce was artificially inoculated with VBNC E. coli O157:H7, resuscitation of the VBNC cells during storage (15 days at 7 °C) was not observed. Based on the results obtained, injured L. monocytogenes cells present in the PW are able to be transferred to the product during washing. If VBNC L. monocytogenes cells present in leafy greens (shredded lettuce and baby spinach), they can resuscitate, although cultivable numbers remained very low. Taking all the results together, it could be concluded that under industrial conditions, VBNC cells can be transferred from water to product during washing, but their capacity to resuscitate in the leafy greens during storage is low.
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Affiliation(s)
- Pilar Truchado
- Research Group on Microbiology and Quality of Fruit and Vegetables, Food Science and Technology Department, CEBAS-CSIC, PO Box 164, E-30100, Espinardo, Spain
| | - Marisa Gómez-Galindo
- Research Group on Microbiology and Quality of Fruit and Vegetables, Food Science and Technology Department, CEBAS-CSIC, PO Box 164, E-30100, Espinardo, Spain
| | - M I Gil
- Research Group on Microbiology and Quality of Fruit and Vegetables, Food Science and Technology Department, CEBAS-CSIC, PO Box 164, E-30100, Espinardo, Spain
| | - Ana Allende
- Research Group on Microbiology and Quality of Fruit and Vegetables, Food Science and Technology Department, CEBAS-CSIC, PO Box 164, E-30100, Espinardo, Spain.
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Han X, Chen Q, Zhang X, Peng J, Zhang M, Zhong Q. The elimination effects of lavender essential oil on Listeria monocytogenes biofilms developed at different temperatures and the induction of VBNC state. Lett Appl Microbiol 2022; 74:1016-1026. [PMID: 35211995 DOI: 10.1111/lam.13681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/20/2022] [Accepted: 02/21/2022] [Indexed: 11/28/2022]
Abstract
Listeria monocytogenes is a typical foodborne pathogen that causes hard-to-treat bacterial infections, mainly due to its ability to form biofilm and enter into a viable but non-culturable state (VBNC). In this study, we investigated the removal effects of four antimicrobial agents on L. monocytogenes biofilms formed at 32 ℃ and 10 ℃, analyzed the resistances of the mature biofilms to antimicrobial agents, and explored the VBNC state of cells in mature biofilms induced by lavender essential oil (LEO). The results showed that the growth of L. monocytogenes was completely inhibited when 1.6% (v/v) of the LEO was added. Meanwhile, the results of the crystal violet staining and XTT reduction method indicated that different concentrations of LEO significantly reduced L. monocytogenes biofilms biomass and metabolic activities, followed by sodium hypochlorite, lactic acid, and hydrogen peroxide. Moreover, the confocal laser scanning microscopy (CLSM) images confirmed that the treated biofilms became thinner, the structure was sparse, and the appearance was blurry. More interestingly, L. monocytogenes biofilms developed at 10 ℃ were less susceptible to the sanitizers than that formed at 32 ℃. In addition, LEO presented a more significant dispersing effect on the biofilm cells, and 1/2 MIC to 4 MIC of LEO could induce fewer VBNC state cells in biofilm and plankton compared with sodium hypochlorite. This study indicated that the LEO could be considered as an ideal antibiofilm agent for controlling L. monocytogenes. But we should pay attention to the resistance of the biofilms developed at low temperatures.
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Affiliation(s)
- Xiangpeng Han
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Qingying Chen
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Xingguo Zhang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Jiayi Peng
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Mengyu Zhang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Qingping Zhong
- Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou, 510642, China.,Guangdong Laboratory of Lingnan Modern Agriculture, South China Agricultural University, Guangzhou, 510642, China
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Hao J, Zhang J, Zheng X, Zhao D. Bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against Listeria monocytogenes planktonic cells and biofilm on food-contact surfaces. FOOD QUALITY AND SAFETY 2022. [DOI: 10.1093/fqsafe/fyab038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
In the present study, the bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against L. monocytogenes planktonic cells and biofilm on food-contact surfaces including stainless steel and glass was systematically evaluated. The results showed that SAEW (pH of 5.09 and available chlorine concentration (ACC) of 60.33 mg/L) could kill L. monocytogenes on food-contact surfaces completely in 30 s, whose disinfection efficacy is equal to that of NaClO solutions (pH of 9.23 and ACC of 253.53 mg/L). The results showed that long exposure time and high ACC contributed to the enhancement of the disinfection efficacy of SAEW on L. monocytogenes on food-contact surfaces. Moreover, the log reduction of SAEW treatment presented an increasing tendency within the prolonging of treatment time when SAEW was used to remove the L. monocytogenes biofilm formed on stainless steel and glass surfaces, which suggested that SAEW could remove L. monocytogenes biofilm effectively and its disinfection efficacy is equal to (in case of stainless steel) or higher than (in case of glass) that of high ACC of NaClO solutions. In addition, the results of the crystal violet staining and scanning electron microscopy (SEM) also demonstrated that SAEW treatment could remove the L. monocytogenes biofilm on food-contact surfaces.
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Affiliation(s)
- Jianxiong Hao
- College of Food Science and Biology, Hebei University of Science and Technology, No.26 Yuxiang Street, Shijiazhuang, Hebei 050018, P. R. China
| | - Junyi Zhang
- College of Food Science and Biology, Hebei University of Science and Technology, No.26 Yuxiang Street, Shijiazhuang, Hebei 050018, P. R. China
| | - Xueqi Zheng
- College of Food Science and Biology, Hebei University of Science and Technology, No.26 Yuxiang Street, Shijiazhuang, Hebei 050018, P. R. China
| | - Dandan Zhao
- College of Food Science and Biology, Hebei University of Science and Technology, No.26 Yuxiang Street, Shijiazhuang, Hebei 050018, P. R. China
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7
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The Bactericidal Efficacy and the Mechanism of Action of Slightly Acidic Electrolyzed Water on Listeria monocytogenes' Survival. Foods 2021; 10:foods10112671. [PMID: 34828952 PMCID: PMC8621911 DOI: 10.3390/foods10112671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/26/2021] [Accepted: 10/29/2021] [Indexed: 11/16/2022] Open
Abstract
In the present work, the bactericidal efficacy and mechanism of slightly acidic electrolyzed water (SAEW) on L. monocytogenes were evaluated. The results showed that the strains of L. monocytogenes were killed completely within 30 s by SAEW whose available chlorine concentration (ACC) was higher than 12 mg/L, and it was confirmed that ACC is the main factor affecting the disinfection efficacy of SAEW. Moreover, our results demonstrated that SAEW could destroy the cell membrane of L. monocytogenes, which was observed by SEM and FT-IR, thus resulting in the leakage of intracellular substances including electrolyte, protein and nucleic acid, and DNA damage. On the other hand, the results found that SAEW could disrupt the intracellular ROS balance of L. monocytogenes by inhibiting the antioxidant enzyme activity, thus promoting the death of L. monocytogenes. In conclusion, the bactericidal mechanism of SAEW on L. monocytogenes was explained from two aspects including the damage of the cell membrane and the breaking of ROS balance.
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Truchado P, Gil MI, Allende A. Peroxyacetic acid and chlorine dioxide unlike chlorine induce viable but non-culturable (VBNC) stage of Listeria monocytogenes and Escherichia coli O157:H7 in wash water. Food Microbiol 2021; 100:103866. [PMID: 34416966 DOI: 10.1016/j.fm.2021.103866] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/07/2021] [Accepted: 06/29/2021] [Indexed: 12/11/2022]
Abstract
The elaboration of guidelines for the industry to establish minimum concentration to prevent cross-contamination during washing practices based on operational limits is the core of the recommended criteria for the use of sanitizers. Several studies have evidenced that sanitizers reduced the levels of foodborne pathogens. However, they might lead to the progress into a viable but non-culturable (VBNC) state of the cells. This evidence has raised concerns regarding the effectiveness of the recommended washing practices for the inactivation of microbial cells present in the process wash water (PWW). The present study evaluated if the most commonly used sanitizers, including sodium hypochlorite (chlorine), peroxyacetic acid (PAA) and chlorine dioxide (ClO2) at established operational limits induced the VBNC stage of Listeria monocytogenes and Escherichia coli O157:H7. Prevention of cross-contamination was examined in four different types of PWW from washing shredded lettuce and cabbage, diced onions, and baby spinach under simulated commercial conditions of high organic matter and 1 min contact time. The results obtained for chlorine showed that recommended operational limits (20-25 mg/L free chlorine) were effective in inactivating L. monocytogenes and E. coli O157:H7 in the different PWWs. However, the operational limits established for PAA (80 mg/L) and ClO2 (3 mg/L) reduced the levels of culturable pathogenic bacteria but induced the VBNC state of the remaining cells. Consequently, the operational limits for chlorine are satisfactory to inactivate foodborne pathogens present in PWW and prevent cross-contamination but higher concentrations or longer contact times should be needed for PAA and ClO2 to reduce the likelihood of the induction of VBNC bacteria cells, as it represents a hazard.
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Affiliation(s)
- Pilar Truchado
- Research Group on Quality and Safety of Fruit and Vegetables, CEBAS-CSIC, Campus Universitario de Espinardo, 25, 30100, Murcia, Spain.
| | - Maria I Gil
- Research Group on Quality and Safety of Fruits and Vegetables, Department of Food Science and Technology, CEBAS-CSIC, Campus, Universitario de Espinardo, 25, 30100, Murcia, Spain
| | - Ana Allende
- Research Group on Quality and Safety of Fruits and Vegetables, Department of Food Science and Technology, CEBAS-CSIC, Campus, Universitario de Espinardo, 25, 30100, Murcia, Spain
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de Medeiros Barbosa I, da Cruz Almeida ÉT, Gomes ACA, de Souza EL. Evidence on the induction of viable but non-culturable state in Listeria monocytogenes by Origanum vulgare L. and Rosmarinus officinalis L. essential oils in a meat-based broth. INNOV FOOD SCI EMERG 2020. [DOI: 10.1016/j.ifset.2020.102351] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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Li Y, Huang TY, Ye C, Chen L, Liang Y, Wang K, Liu J. Formation and Control of the Viable but Non-culturable State of Foodborne Pathogen Escherichia coli O157:H7. Front Microbiol 2020; 11:1202. [PMID: 32612584 PMCID: PMC7308729 DOI: 10.3389/fmicb.2020.01202] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/12/2020] [Indexed: 02/05/2023] Open
Abstract
As a common foodborne pathogen, Escherichia coli O157:H7 produces toxins causing serious diseases. However, traditional methods failed in detecting E. coli O157:H7 cells in the viable but non-culturable (VBNC) state, which poses a threat to food safety. This study aimed at investigating the formation, control, and detection of the VBNC state of E. coli O157:H7. Three factors including medium, salt, and acid concentrations were selected as a single variation. Orthogonal experiments were designed with three factors and four levels, and 16 experimental schemes were used. The formation of the VBNC state was examined by agar plate counting and LIVE/DEAD® BacLightTM bacterial viability kit with fluorescence microscopy. According to the effects of environmental conditions on the formation of the VBNC state of E. coli O157:H7, the inhibition on VBNC state formation was investigated. In addition, E. coli in the VBNC state in food samples (crystal cake) was detected by propidium monoazide-polymerase chain reaction (PMA-PCR) assays. Acetic acid concentration showed the most impact on VBNC formation of E. coli O157:H7, followed by medium and salt concentration. The addition of 1.0% acetic acid could directly kill E. coli O157:H7 and eliminate its VBNC formation. In crystal cake, 25, 50, or 100% medium with 1.0% acetic acid could inhibit VBNC state formation and kill E. coli O157:H7 within 3 days. The VBNC cell number was reduced by adding 1.0% acetic acid. PMA-PCR assay could be used to detect E. coli VBNC cells in crystal cake with detection limit at 104 CFU/ml. The understanding on the inducing and inhibitory conditions for the VBNC state of E. coli O157:H7 in a typical food system, as well as the development of an efficient VBNC cell detection method might aid in the control of VBNC E. coli O157:H7 cells in the food industry.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Teng-Yi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Congxiu Ye
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Yi Liang
- Guangdong Zhongqing Font Biochemical Science and Technology Co. Ltd., Maoming, China
| | - Kan Wang
- Research Center for Translational Medicine, The Second Affiliated Hospital, Medical College of Shantou University, Shantou, China
- *Correspondence: Junyan Liu,
| | - Junyan Liu
- Department of Civil and Environmental Engineering, A. James Clark School of Engineering, University of Maryland, College Park, MD, United States
- Kan Wang,
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11
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Ogunniyi AD, Dandie CE, Ferro S, Hall B, Drigo B, Brunetti G, Venter H, Myers B, Deo P, Donner E, Lombi E. Comparative antibacterial activities of neutral electrolyzed oxidizing water and other chlorine-based sanitizers. Sci Rep 2019; 9:19955. [PMID: 31882630 PMCID: PMC6934530 DOI: 10.1038/s41598-019-56248-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/29/2019] [Indexed: 12/16/2022] Open
Abstract
There is increasing demand for safe and effective sanitizers for irrigation water disinfection to prevent transmission of foodborne pathogens to fresh produce. Here we compared the efficacy of pH-neutral electrolyzed oxidizing water (EOW), sodium hypochlorite (NaClO) and chlorine dioxide (ClO2) against single and mixed populations of E. coli, Listeria and Salmonella under a range of pH and organic matter content. EOW treatment of the mixed bacterial suspension resulted in a dose-dependent (<1 mg/L free chlorine), rapid (<2 min) and effective (4-6 Log10) reduction of the microbial load in water devoid of organic matter under the range of pH conditions tested (pH, 6.0, 7.0, 8.4 and 9.2). The efficacy of EOW containing 5 mg/L free chlorine was unaffected by increasing organic matter, and compared favourably with equivalent concentrations of NaClO and ClO2. EOW at 20 mg/L free chlorine was more effective than NaClO and ClO2 in reducing bacterial populations in the presence of high (20-100 mg/L) dissolved organic carbon, and no regrowth or metabolic activity was observed for EOW-treated bacteria at this concentration upon reculturing in rich media. Thus, EOW is as effective or more effective than other common chlorine-based sanitizers for pathogen reduction in contaminated water. EOW's other characteristics, such as neutral pH and ease of handling, indicate its suitability for fresh produce sanitation.
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Affiliation(s)
- Abiodun D Ogunniyi
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia.
| | - Catherine E Dandie
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia
| | - Sergio Ferro
- Ecas4 Australia Pty Ltd, 8/1 London Road, Mile End South, South Australia, Australia
| | - Barbara Hall
- Plant Health and Biosecurity, SARDI, Adelaide, South Australia, Australia
| | - Barbara Drigo
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia
| | - Gianluca Brunetti
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia
| | - Henrietta Venter
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Baden Myers
- Natural and Built Environments Research Centre, School of Natural and Built Environments, University of South Australia, Mawson Lakes, South Australia, Australia
| | - Permal Deo
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Erica Donner
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia
| | - Enzo Lombi
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia
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12
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Sherman‐Wood R, Tikekar RV. Decontamination of irrigation water using a combined sand filtration and UV‐C light treatment. J Food Saf 2019. [DOI: 10.1111/jfs.12744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Robert Sherman‐Wood
- Department of Nutrition and Food Science University of Maryland College Park Maryland
| | - Rohan V. Tikekar
- Department of Nutrition and Food Science University of Maryland College Park Maryland
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