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Byun KH, Kang M, Seon Koo M, Lim MC, Sik Ok G, Jung Kim H. Potential risk of biofilm-forming Bacillus cereus group in fresh-cut lettuce production chain. Food Res Int 2024; 191:114692. [PMID: 39059950 DOI: 10.1016/j.foodres.2024.114692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 06/24/2024] [Accepted: 06/26/2024] [Indexed: 07/28/2024]
Abstract
Bacillus cereus and Bacillus thuringiensis, which belong to the B. cereus group, are widely distributed in nature and can cause food poisoning symptoms. In this study, we collected 131 isolates belonging to the B. cereus group, comprising 124B. cereus and seven B. thuringiensis isolates, from fresh-cut lettuce production chain and investigated their potential risk by analyzing genotypic (enterotoxin and emetic toxin gene profiles) and phenotypic (antibiotic susceptibility, sporulation, and biofilm formation) characteristics. Enterotoxin genes were present only in B. cereus, whereas the emetic toxin gene was not detected in any of the B. cereus isolates. All isolates were susceptible to vancomycin, which is a last resort for treating B. cereus group infection symptoms, but generally resistant to β-lactam antimicrobials, and had the ability to form spores (at an average sporulation rate of 24.6 %) and biofilms at 30 °C. Isolates that formed strong biofilms at 30 °C had a superior possibility of forming a dense biofilm by proliferating at 10 °C compared to other isolates. Additionally, confocal laser scanning microscopy (CLSM) images revealed a notable presence of spores within the submerged biofilm formed at 10 °C, and the strengthened attachment of biofilm inner cells to the substrate was further revealed through biofilm structure parameters analysis. Collectively, our study revealed the prevalence and contamination levels of B. cereus and B. thuringiensis at fresh-cut lettuce production chain and investigated their genotypic and phenotypic characteristics, aiming to provide valuable insights for the development of potential risk management strategies to ensure food safety, especially along the cold chain.
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Affiliation(s)
- Kye-Hwan Byun
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Technology Innovation Research Division, Hygienic Safety and Materials Research Group, World Institute of Kimchi, Gwangju 61755, Republic of Korea
| | - Miseon Kang
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Department of Food Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Min Seon Koo
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Department of Food Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Min-Cheol Lim
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Department of Food Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Gyeong Sik Ok
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea
| | - Hyun Jung Kim
- Food Safety and Distribution Research Group, Korea Food Research Institute, Wanju, Jeollabuk-do 55365, Republic of Korea; Department of Food Biotechnology, University of Science and Technology, Daejeon 34113, Republic of Korea.
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Schmid PJ, Forstner P, Kittinger C. Sliding motility of Bacillus cereus mediates vancomycin pseudo-resistance during antimicrobial susceptibility testing. J Antimicrob Chemother 2024; 79:1628-1636. [PMID: 38785365 PMCID: PMC11215547 DOI: 10.1093/jac/dkae156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND The glycopeptide vancomycin is the antimicrobial agent-of-choice for the treatment of severe non-gastrointestinal infections with members of Bacillus cereus sensu lato (s.l.). Recently, sporadic detection of vancomycin-resistant phenotypes emerged, mostly for agar diffusion testing such as the disc diffusion method or gradient test (e.g. Etest®) method. RESULTS In this work, we were able to disprove a preliminarily assumed high resistance to vancomycin in an isolate of B. cereus s.l. using broth microdilution and agar dilution. Microscopic imaging during vancomycin susceptibility testing showed spreading towards the inhibition zone, which strongly suggested sliding motility. Furthermore, transcriptomic analysis using RNA-Seq on the nanopore platform revealed several key genes of biofilm formation (e.g. calY, tasA, krsEABC) to be up-regulated in pseudo-resistant cells, substantiating that bacterial sliding is responsible for the observed mobility. Down-regulation of virulence (e.g. hblABCD, nheABC, plcR) and flagellar genes compared with swarming cells also confirmed the non-swarming phenotype of the pseudo-resistant isolate. CONCLUSIONS The results highlight an insufficiency of agar diffusion testing for vancomycin susceptibility in the B. cereus group, and reference methods like broth microdilution are strongly recommended. As currently no guideline mentions interfering phenotypes in antimicrobial susceptibility testing of B. cereus s.l., this knowledge is essential to obtain reliable results on vancomycin susceptibility. In addition, this is the first report of sliding motility undermining accurate antimicrobial susceptibility testing in B. cereus s.l. and may serve as a basis for future studies on bacterial motility in susceptibility testing and its potential impact on treatment efficacy.
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Affiliation(s)
- Paul J Schmid
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Diagnostic and Research Center for Molecular Biomedicine, Medical University of Graz, Graz, Austria
| | - Patrick Forstner
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Diagnostic and Research Center for Molecular Biomedicine, Medical University of Graz, Graz, Austria
| | - Clemens Kittinger
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Diagnostic and Research Center for Molecular Biomedicine, Medical University of Graz, Graz, Austria
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Park KM, Kim HJ, Park KJ, Koo M. Susceptibility of emetic and enterotoxigenic Bacillus cereus grown at high temperature to disinfectants. Heliyon 2023; 9:e16863. [PMID: 37484226 PMCID: PMC10360960 DOI: 10.1016/j.heliyon.2023.e16863] [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: 12/01/2022] [Revised: 05/14/2023] [Accepted: 05/31/2023] [Indexed: 07/25/2023] Open
Abstract
The prevalence of emetic strains in food products is rare; however, infection with these may be fatal to the vulnerable population. Bacterial control of the emetic Bacillus cereus strains is still unclear. This study aimed to assess the influence of high temperature on the disinfection of emetic and enterotoxigenic B. cereus. Emetic B. cereus strains survived up to 50 °C; the lag time and maximum growth rate were higher at 42 °C than those at 30 °C. Compared to enterotoxigenic B. cereus, all emetic food strains showed higher minimum inhibitory concentrations and minimum bactericidal concentrations for sodium hypochlorite and citric acid. The disinfectant susceptibility of the emetic B. cereus OS-05 strain incubated at a higher temperature did not increase and was maintained at the highest MBC value. In all emetic B. cereus strains, enterotoxin gene expression was upregulated at 42 °C and 45 °C. Increased ces gene expression was also found in emetic B. cereus strains GP-15 and OS-05, with upregulation of 128- and 820-fold at 42 °C. Thus, emetic B. cereus grown at high temperatures may resist common disinfectants of the food industry. The findings may help control B. cereus in food or the food processing industry.
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Affiliation(s)
- Kyung Min Park
- Department of Food Safety and Distribution Research Group, Korea Research Institute, Wanju-gun, 55365, Jeollabuk-do, South Korea
| | - Hyun Jung Kim
- Department of Food Safety and Distribution Research Group, Korea Research Institute, Wanju-gun, 55365, Jeollabuk-do, South Korea
- Department of Food Biotechnology, Korea University of Science & Technology, Daejeon, 34113, South Korea
| | - Kee Jai Park
- Department of Food Safety and Distribution Research Group, Korea Research Institute, Wanju-gun, 55365, Jeollabuk-do, South Korea
| | - Minseon Koo
- Department of Food Safety and Distribution Research Group, Korea Research Institute, Wanju-gun, 55365, Jeollabuk-do, South Korea
- Department of Food Biotechnology, Korea University of Science & Technology, Daejeon, 34113, South Korea
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4
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Yang H, Yeom W, Oh J, Kim H, Beuchat LR, Ryu JH. Antimicrobial effects of essential oil vapors on Bacillus cereus on nutrient agar and iceberg lettuce. FOOD BIOSCI 2023. [DOI: 10.1016/j.fbio.2023.102580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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Kim SH, Yehuala GA, Bang WY, Yang J, Jung YH, Park MK. Safety Evaluation of Bacillus subtilis IDCC1101, Newly Isolated from Cheonggukjang, for Industrial Applications. Microorganisms 2022; 10:microorganisms10122494. [PMID: 36557747 PMCID: PMC9784242 DOI: 10.3390/microorganisms10122494] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/11/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
The present study aimed to evaluate the safety of Bacillus subtilis (BS) IDCC1101, newly isolated from Cheonggukjang in Korea. Genome sequencing of BS IDCC1101 was performed to investigate the presence of secondary metabolites, virulence, antibiotic resistance, and mobile elements. Its phenotypic safety analyses included antibiotic susceptibility, enzyme activity, carbohydrate utilization, production of biogenic amines (BAs) and D-/L-lactate, hemolytic activity, and toxicities in HaCaT cells and rats. The genome of BS IDCC1101 consisted of 4,118,950 bp with 3077 functional genes. Among them, antimicrobial and antifungal secondary metabolites were found, such as fengycin, bacillibactin, and bacilysin. Antibiotic resistance and virulence genes did not exhibit transferability since they did not overlap with mobile elements in the genome. BS IDCC1101 was susceptible to almost all antibiotics suggested for assessment of BS's antibiotic susceptibility by EFSA guidelines, except for streptomycin. BS IDCC1101 showed the utilization of a wide range of 27 carbohydrates, as well as enzyme activities such as alkaline phosphatase, esterase, esterase lipase, naphthol-AS-BI-phosphohydrolase, α-galactosidase, β-galactosidase, α-glucosidase, and β-glucosidase activities. Additionally, BS IDCC1101 did not exhibit the production of D-/L-lactate and hemolytic activities. Its toxicity in HaCaT cells and rats was also not detected. Thus, these genotypic and phenotypic findings indicate that BS IDCC1101 can be safely used for industrial applications.
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Affiliation(s)
- Su-Hyeon Kim
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea
- Food and Bio-Industry Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Gashaw Assefa Yehuala
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea
- Department of Food Engineering, College of Biological and Chemical Engineering, Addis Ababa Science and Technology University, Addis Ababa 16417, Ethiopia
| | - Won Yeong Bang
- Ildong Bioscience, Pyeongtaek-si 17957, Republic of Korea
| | - Jungwoo Yang
- Ildong Bioscience, Pyeongtaek-si 17957, Republic of Korea
| | - Young Hoon Jung
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea
- Food and Bio-Industry Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Mi-Kyung Park
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea
- Food and Bio-Industry Research Institute, Kyungpook National University, Daegu 41566, Republic of Korea
- Correspondence: ; Tel.: +82-53-950-5776
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Lin W, Xu F, Guo H, Cui L. Domestic refrigerators: An overlooked breeding ground of antibiotic resistance genes and pathogens. ENVIRONMENT INTERNATIONAL 2022; 170:107647. [PMID: 36413928 DOI: 10.1016/j.envint.2022.107647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/18/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
Domestic refrigerator is a widely used appliance to keep food fresh and retard food spoilage in household. However, our understanding of microbial health risk associated with food under such circumstance still remains very poor. Here, typical types of food (vegetable, fish, and pork) were kept in a domestic refrigerator at 4 °C for 3-30 days. Temporal dynamics of antibiotic resistome, pathogens, bacterial and fungal communities during this period were investigated via high-throughput quantification and Illumina sequencing technologies. Results showed that a large number (21-134) of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) were detected across the three food types, including 10.06 % of high-risk ARGs classified by their risk ranks. Moreover, four bacterial pathogens (i.e., Bacillus cereus, Cronobacter spp., Klebsiella pneumoniae and Staphylococcus aureus) targeted by marker genes including the pathogen-specific genes or virulence factor genes, and some potential fungal pathogens (e.g., Fusarium, Candida, and Aspergillus) were detected, indicating the occurrence of microbial risk even at the normally regarded safe storage temperature. Among all food types, the total bacterial density and ARG abundances in fish rapidly increased after only 3 days, much faster than vegetable and pork after 10 days. In addition, fish samples contained the highest ARG and pathogen abundances, indicating its potentially higher health risk than other food types. Finally, the shifts of ARG pattern were mainly contributed by bacterial communities and MGEs. This study highlights that food preserved in refrigerator at 4 °C could still be an unneglected microbial risk, and raises awareness of improving food safety in domestic environment.
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Affiliation(s)
- Wenfang Lin
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Fei Xu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Hongqin Guo
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Cui
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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Zhao X, Zervas A, Hendriks M, Rajkovic A, van Overbeek L, Hendriksen NB, Uyttendaele M. Identification and characterization of Bacillus thuringiensis and other Bacillus cereus group isolates from spinach by whole genome sequencing. Front Microbiol 2022; 13:1030921. [PMID: 36569082 PMCID: PMC9771606 DOI: 10.3389/fmicb.2022.1030921] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/09/2022] [Indexed: 12/05/2022] Open
Abstract
Bacillus thuringiensis (Bt), used as a biological control agent (BCA), can persist on plants, and from there can be introduced into the final food product. In routine food safety diagnostics, these Bt residues cannot be distinguished from natural populations of Bacillus cereus present in plants and all are enumerated as "presumptive B. cereus." In this study, information on eventual use of Bt biopesticides, brand, application times and intervals provided by three food processing companies in Belgium, were integrated with quantitative data on presumptive B. cereus measured from fresh to frozen food products. This information together with data on genomic similarity obtained via whole genome sequencing (WGS) and cry gene profiling using a quantitative real-time PCR (qPCR) assay, confirmed that six out of 11 Bt isolates originated from the applied Bt biocontrol products. These identified Bt strains were shown to carry enterotoxin genes (nhe, hbl, cytK-2) and express Hbl enterotoxin in vitro. It was also noted that these Bt biopesticide strains showed no growth at standard refrigeration temperatures and a low or moderate biofilm-forming ability and cytotoxic activity. Our results also showed that the use of Bt as a BCA on spinach plants in the field led to higher residual counts of Bt in spinach (fresh or frozen) in the food supply chain, but the residual counts exceeding at present commonly assumed safety limit of 105 CFU/g was only found in one fresh spinach sample. It is therefore recommended to establish a pre-harvest interval for Bt biopesticide application in the field to lower the likelihood of noncompliance to the generic B. cereus safety limit. Furthermore, WGS was found to be the best way to identify Bt biopesticide isolates at the strain level for foodborne outbreaks and clinical surveillance. The developed qPCR assay for screening on the presence of cry genes in presumptive B. cereus can be applied as a rapid routine test as an amendment to the already existing test on Bt crystal proteins determined via phase-contrast microscopy.
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Affiliation(s)
- Xingchen Zhao
- Food Microbiology and Food Preservation Research Unit, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium,*Correspondence: Xingchen Zhao,
| | - Athanasios Zervas
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Marc Hendriks
- Wageningen Plant Research, Wageningen University and Research, Wageningen, Netherlands
| | - Andreja Rajkovic
- Food Microbiology and Food Preservation Research Unit, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Leo van Overbeek
- Wageningen Plant Research, Wageningen University and Research, Wageningen, Netherlands
| | | | - Mieke Uyttendaele
- Food Microbiology and Food Preservation Research Unit, Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Hwang D, Oh TY, Baek SY, Kang MS, Hong SI, Kim HJ. Enterotoxin genes, biofilm formation, and antimicrobial and disinfectant resistance of Bacillus cereus isolates from primary producing stages. Food Control 2022. [DOI: 10.1016/j.foodcont.2022.109196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Jung J, Jin H, Seo S, Jeong M, Kim B, Ryu K, Oh K. Short Communication: Enterotoxin Genes and Antibiotic Susceptibility of Bacillus cereus Isolated from Garlic Chives and Agricultural Environment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:12159. [PMID: 36231461 PMCID: PMC9564537 DOI: 10.3390/ijerph191912159] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/17/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
This study aims to investigate the enterotoxin profiles and antibiotic susceptibility of Bacillus cereus isolated from garlic chives and environmental samples. A total of 103 B. cereus isolates were used to identify enterotoxin genes, including hblA, hblC, hblD, nheA, nheB, and nheC. The hemolysin BL enterotoxin complex (hblACD) was detected in 38 isolates (36.9%), and the non-hemolytic enterotoxin complex (nheABC) was detected in 8 (7.8%) isolates. Forty-five isolates (43.7%) had hblACD and nheABC genes. B. cereus was resistant to β-lactam antibiotics and susceptible to non-β-lactam antibiotics. However, some B. cereus strains showed intermediate resistance to β-lactam and non-β-lactam antibiotics. B. cereus isolated from garlic chives showed intermediate resistance to cefotaxime (7.7%), rifampin (15.4%), clindamycin (30.8%), erythromycin (7.7%), and tetracycline (7.7%). B. cereus isolates from the agricultural environment were moderately resistant to cefotaxime (18.9%), rifampin (15.6%), clindamycin (12.2%), erythromycin (4.4%), and tetracycline (5.6%). Moreover, B. cereus isolates from garlic chives and cultivation environments could change their antibiotic resistance profile from susceptible to intermediate-resistant to rifampin, clindamycin, erythromycin, and tetracycline and exhibit multidrug resistance. These results indicate that continuous monitoring of B. cereus contamination in the produce and agricultural environment might be needed to ensure the safety of consuming fresh vegetables.
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Affiliation(s)
- Jieun Jung
- Functional Food Division, Department of Agro-Food Resources, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun 55365, Jeolloabuk-do, Korea
| | - Hyeonsuk Jin
- Microbial Safety Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun 55365, Jeollabuk-do, Korea
| | - Seungmi Seo
- Microbial Safety Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun 55365, Jeollabuk-do, Korea
| | - Myeongin Jeong
- Microbial Safety Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun 55365, Jeollabuk-do, Korea
| | - Boeun Kim
- Microbial Safety Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun 55365, Jeollabuk-do, Korea
| | - Kyoungyul Ryu
- Microbial Safety Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun 55365, Jeollabuk-do, Korea
| | - Kwangkyo Oh
- Microbial Safety Division, Department of Agro-food Safety and Crop Protection, National Institute of Agricultural Sciences, Rural Development Administration, Wanju-gun 55365, Jeollabuk-do, Korea
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Kowalska J, Maćkiw E, Korsak D, Postupolski J. Characteristic and Antimicrobial Resistance of <i>Bacillus cereus</i> Group Isolated from Food in Poland. POL J FOOD NUTR SCI 2022. [DOI: 10.31883/pjfns/152677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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11
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Rajalingam N, Jung J, Seo SM, Jin HS, Kim BE, Jeong MI, Kim D, Ryu JG, Ryu KY, Oh KK. Prevalence, distribution, enterotoxin profiles, antimicrobial resistance, and genetic diversity of Bacillus cereus group isolates from lettuce farms in Korea. Front Microbiol 2022; 13:906040. [PMID: 36081801 PMCID: PMC9445581 DOI: 10.3389/fmicb.2022.906040] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/31/2022] [Indexed: 11/28/2022] Open
Abstract
Lettuce wraps are popular in Korean cuisine for their high nutritional value and versatility as healthy additions to multiple dishes. Microbial contamination of lettuce is a major concern, as lettuce is consumed fresh without cooking. Among foodborne pathogens, the spore-forming, facultative anaerobic bacterium, Bacillus cereus is one of the frequently detected pathogen in lettuce in Korea. In this study, we investigated the prevalence and distribution of Bacillus cereus strains in lettuce production farms and further evaluated the enterotoxin gene profiles, antibiotic susceptibility, multidrug resistance pattern, and genetic differences among the B. cereus group isolates. Of the 140 samples isolated from 10 lettuce production farms, 30 samples (21.42%) were positive for B. cereus in which 19 (31.6%) and 10 (23.25%) were from soil and lettuce, respectively. The enterotoxin patterns A (hblCDA, nheABC, entFM, and cytK genes) and B (hblCDA, nheABC, and entFM genes) accounted for 50% and 20% of all the isolates, whereas the emetic gene cesB was not detected in any of the B. cereus group isolates. Antibiotic susceptibility testing of the B. cereus group isolates revealed that all the strains were predominantly resistant to β-lactam antibiotics except imipenem and generally susceptible to most of the non β-lactam antibiotics, including gentamycin, streptomycin, chloramphenicol, and tetracycline. ERIC-PCR and MLST analysis revealed high genetic diversity among the 30 B. cereus group isolates, which belonged to 26 different sequence types (STs) and seven new STs. Moreover, isolates with identical STs exhibited similar patterns of antibiotic resistance and enterotoxin profiles. Results of this study indicate a high prevalence of B. cereus group isolates in lettuce production farms in the Republic of Korea.
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Affiliation(s)
- Nagendran Rajalingam
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Jieun Jung
- Functional Food and Nutrition Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Seung-Mi Seo
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Hyun-Sook Jin
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Bo-Eun Kim
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Myeong-In Jeong
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Dawoon Kim
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Jae-Gee Ryu
- Planning and Coordination Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Kyoung-Yul Ryu
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
| | - Kwang Kyo Oh
- Microbial Safety Division, National Institute of Agricultural Sciences, Rural Development Administration, Wanju, South Korea
- *Correspondence: Kwang Kyo Oh,
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Park KM, Kim HJ, Park KJ, Koo M. Toxigenic Potential of Mesophilic and Psychrotolerant Bacillus cereus Isolates from Chilled Tofu. Foods 2022; 11:foods11121674. [PMID: 35741876 PMCID: PMC9222640 DOI: 10.3390/foods11121674] [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: 05/09/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 12/04/2022] Open
Abstract
The prevalence, toxin gene profile, antibiogram, and biofilm formation to determine the virulence potential of mesophilic and psychrotolerant Bacillus cereus (B. cereus) isolated from chilled tofu were investigated. Among 58 isolates, 21 isolates were capable of growth at 7 °C, and these isolates shared a potential hazard for food poisoning with mesophilic isolates. B. cereus harboring enterotoxin genes was more frequently found in psychrotolerant isolates than in mesophilic isolates. Thirty-seven (62.2%) mesophilic isolates and all psychrotolerant isolates carried four or more enterotoxin genes. The hemolysin BL (42.9%) and nonhemolytic enterotoxin complexes (90.5%) were found at a higher frequency in psychrotolerant isolates than in mesophilic isolates. Some B. cereus isolates showed resistance to rifampicin or clindamycin, regardless of mesophilic and psychrotolerant isolates. A total of 56% and 40% mesophilic isolates displayed the strongest biofilm formation at 40 and 42 °C, respectively. However, the biofilm formation of psychrotolerant isolates was not significantly affected by temperature. The results of this study provide new strategies for the development of bacterial control, which allows us to optimize technologies to inhibit B. cereus, including psychrotolerant isolates, in the food industry.
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Affiliation(s)
- Kyung-Min Park
- Department of Food Safety and Distribution Research Group, Korea Research Institute, Wanju-gun 55365, Korea; (K.-M.P.); (H.-J.K.); (K.-J.P.)
| | - Hyun-Jung Kim
- Department of Food Safety and Distribution Research Group, Korea Research Institute, Wanju-gun 55365, Korea; (K.-M.P.); (H.-J.K.); (K.-J.P.)
- Department of Food Biotechnology, Korea University of Science & Technology, Daejeon 34113, Korea
| | - Kee-Jai Park
- Department of Food Safety and Distribution Research Group, Korea Research Institute, Wanju-gun 55365, Korea; (K.-M.P.); (H.-J.K.); (K.-J.P.)
| | - Minseon Koo
- Department of Food Safety and Distribution Research Group, Korea Research Institute, Wanju-gun 55365, Korea; (K.-M.P.); (H.-J.K.); (K.-J.P.)
- Department of Food Biotechnology, Korea University of Science & Technology, Daejeon 34113, Korea
- Correspondence: ; Tel.: +82-63-219-9161
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Jovanovic J, Tretiak S, Begyn K, Rajkovic A. Detection of Enterotoxigenic Psychrotrophic Presumptive Bacillus cereus and Cereulide Producers in Food Products and Ingredients. Toxins (Basel) 2022; 14:toxins14040289. [PMID: 35448897 PMCID: PMC9030337 DOI: 10.3390/toxins14040289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 04/07/2022] [Accepted: 04/13/2022] [Indexed: 02/04/2023] Open
Abstract
In the last decade, foodborne outbreaks and individual cases caused by bacterial toxins showed an increasing trend. The major contributors are enterotoxins and cereulide produced by Bacillus cereus, which can cause a diarrheal and emetic form of the disease, respectively. These diseases usually induce relatively mild symptoms; however, fatal cases have been reported. With the aim to detected potential toxin producers that are able to grow at refrigerator temperatures and subsequently produce cereulide, we screened the prevalence of enterotoxin and cereulide toxin gene carriers and the psychrotrophic capacity of presumptive B. cereus obtained from 250 food products (cereal products, including rice and seeds/pulses, dairy-based products, dried vegetables, mixed food, herbs, and spices). Of tested food products, 226/250 (90.4%) contained presumptive B. cereus, which communities were further tested for the presence of nheA, hblA, cytK-1, and ces genes. Food products were mainly contaminated with the nheA B. cereus carriers (77.9%), followed by hblA (64.8%), ces (23.2%), and cytK-1 (4.4%). Toxigenic B. cereus communities were further subjected to refrigerated (4 and 7 °C) and mild abuse temperatures (10 °C). Overall, 77% (94/121), 86% (104/121), and 100% (121/121) were able to grow at 4, 7, and 10 °C, respectively. Enterotoxin and cereulide potential producers were detected in 81% of psychrotrophic presumptive B. cereus. Toxin encoding genes nheA, hblA, and ces gene were found in 77.2, 55, and 11.7% of tested samples, respectively. None of the psychrotrophic presumptive B. cereus were carriers of the cytotoxin K-1 encoding gene (cytK-1). Nearly half of emetic psychrotrophic B. cereus were able to produce cereulide in optimal conditions. At 4 °C none of the examined psychrotrophs produced cereulide. The results of this research highlight the high prevalence of B. cereus and the omnipresence of toxin gene harboring presumptive B. cereus that can grow at refrigerator temperatures, with a focus on cereulide producers.
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Affiliation(s)
- Jelena Jovanovic
- Department of Food Technology, Safety, and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (J.J.); (K.B.)
| | - Svitlana Tretiak
- Department of Pathobiology, Pharmacology and Zoological Medicine, Ghent University, Salisburylaan 133, D5 Ingang 78, 9820 Merelbeke, Belgium;
- Impextraco nv, Wiekevorstsesteenweg 38, 2220 Heist-op-den-Berg, Belgium
| | - Katrien Begyn
- Department of Food Technology, Safety, and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (J.J.); (K.B.)
| | - Andreja Rajkovic
- Department of Food Technology, Safety, and Health, Ghent University, Coupure Links 653, 9000 Ghent, Belgium; (J.J.); (K.B.)
- Correspondence:
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14
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Kim T, Heo S, Na HE, Lee G, Kim JH, Kwak MS, Sung MH, Jeong DW. Bacterial Community of Galchi-Baechu Kimchi Based on Culture-Dependent and - Independent Investigation and Selection of Starter Candidates. J Microbiol Biotechnol 2022; 32:341-347. [PMID: 35001009 PMCID: PMC9628854 DOI: 10.4014/jmb.2112.12003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/24/2021] [Accepted: 12/27/2021] [Indexed: 12/15/2022]
Abstract
In this study, the bacterial community of galchi-baechu kimchi was determined using culture-based and culture-independent techniques (next generation sequencing:NGS), and showed discrepancies between results. Weissella koreensis and Pediococcus inopinatus were the dominant species according to the NGS results, while Bacillus species and P. inopinatus were dominant in the culture-dependent analysis. To identify safe starter candidates, sixty-five Bacillus strains isolated from galchi-baechu kimchi using culture-dependent methods were evaluated for their antibiotic resistance, presence of toxin genes, and hemolytic activity. Strains were then assessed for salt tolerance and protease and lipase activity. As a result, four strains-B. safensis GN5_10, B. subtilis GN5_19, B. velezensis GN5_25, and B. velezensis GT8-were selected as safe starter candidates for use in fermented foods.
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Affiliation(s)
- Tao Kim
- Department of Food and Nutrition, Dongduk Women’s University, Seoul 02748, Republic of Korea
| | - Sojeong Heo
- Department of Food and Nutrition, Dongduk Women’s University, Seoul 02748, Republic of Korea
| | - Hong-Eun Na
- Department of Food and Nutrition, Dongduk Women’s University, Seoul 02748, Republic of Korea
| | - Gawon Lee
- Department of Food and Nutrition, Dongduk Women’s University, Seoul 02748, Republic of Korea
| | - Jong-Hoon Kim
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Republic of Korea
| | - Mi-Sun Kwak
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Republic of Korea
| | - Moon-Hee Sung
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Republic of Korea,KookminBio Corporation, Seoul 02826, Republic of Korea,
M.H. Sung Phone: +82-910-4808 E-mail:
| | - Do-Won Jeong
- Department of Food and Nutrition, Dongduk Women’s University, Seoul 02748, Republic of Korea,Corresponding authors D.W. Jeong Phone: +82-2-940-4463 E-mail:
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15
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Ríos‐López AL, Heredia N, García S, Merino‐Mascorro JÁ, Solís‐Soto LY, Dávila‐Aviña JE. Effect of phenolic compounds and cold shock on survival and virulence of
Escherichia coli
pathotypes. J Food Saf 2022. [DOI: 10.1111/jfs.12966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ana L. Ríos‐López
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas Universidad Autónoma de Nuevo León San Nicolás de los Garza Mexico
| | - Norma Heredia
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas Universidad Autónoma de Nuevo León San Nicolás de los Garza Mexico
| | - Santos García
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas Universidad Autónoma de Nuevo León San Nicolás de los Garza Mexico
| | - José Á. Merino‐Mascorro
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas Universidad Autónoma de Nuevo León San Nicolás de los Garza Mexico
| | - Luisa Y. Solís‐Soto
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas Universidad Autónoma de Nuevo León San Nicolás de los Garza Mexico
| | - Jorge E. Dávila‐Aviña
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas Universidad Autónoma de Nuevo León San Nicolás de los Garza Mexico
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16
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Fuchs E, Raab C, Brugger K, Ehling-Schulz M, Wagner M, Stessl B. Performance Testing of Bacillus cereus Chromogenic Agar Media for Improved Detection in Milk and Other Food Samples. Foods 2022; 11:foods11030288. [PMID: 35159440 PMCID: PMC8834558 DOI: 10.3390/foods11030288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/05/2022] [Accepted: 01/10/2022] [Indexed: 02/07/2023] Open
Abstract
In this study, the performance of four alternative selective chromogenic B. cereus agar was compared to the reference mannitol-yolk polymyxin (MYP) agar (ISO 7932) using inclusion and exclusion test strains (n = 110) and by analyzing naturally contaminated milk and other food samples (n = 64). Subsequently, the panC group affiliation and toxin gene profile of Bacillus cereus senso lato (s.l.) isolates were determined. Our results corroborate that the overall best performing media CHROMagar™ B. cereus (93.6% inclusivity; 82.7% exclusivity) and BACARA® (98.2% inclusivity, 62.7% exclusivity) are more sensitive and specific compared to Brilliance™ B. cereus, MYP and ChromoSelect Bacillus Agar. Both media allow unequivocal detection of B. cereus with low risks of misidentification. Media containing ß-D-glucosidase for the detection of presumptive B. cereus may form atypical colony morphologies resulting in a false negative evaluation of the sample. Naturally contaminated samples presented high numbers of background flora, while numbers of presumptive B. cereus were below the detection limit (<10 CFU g−1 or mL−1). Recovery after freezing resulted in the highest detection of B. cereus s.l. on BACARA® (57.8%), CHROMagar™ B. cereus (56.3%) and MYP agar (54.7%). The panC/toxin profile combination IV/A was the most abundant (33.0%), followed by III/F (21.7%) and VI/C (10.4%). More panC and toxin combinations were present in 15.6% of samples when reanalyzed after freezing. In order to improve detection and confirmation of B. cereus s.l. in food samples, we recommend the parallel use of two complementary selective media followed by molecular characterization (e.g., panC typing combined with toxin gene profiling). When determining psychrotolerant or thermophilic members of the B. cereus group, the selective agar media should additionally be incubated at appropriate temperatures (5 °C, ≥45 °C). If high-risk toxin genes (e.g., ces or cytK-1) are detected, the strain-specific ability to produce toxin should be examined to decisively assess risk.
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Affiliation(s)
- Eva Fuchs
- Unit of Food Microbiology, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.F.); (C.R.); (M.W.)
| | - Christina Raab
- Unit of Food Microbiology, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.F.); (C.R.); (M.W.)
| | - Katharina Brugger
- Unit of Veterinary Public Health and Epidemiology, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria;
| | - Monika Ehling-Schulz
- Functional Microbiology Group, Institute of Microbiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria;
| | - Martin Wagner
- Unit of Food Microbiology, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.F.); (C.R.); (M.W.)
- Austrian Competence Center for Feed and Food Quality, Safety and Innovation (FFOQSI GmbH), 3430 Tulln an der Donau, Austria
| | - Beatrix Stessl
- Unit of Food Microbiology, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (E.F.); (C.R.); (M.W.)
- Correspondence:
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17
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Predicting B. cereus growth and cereulide production in dairy mix. Int J Food Microbiol 2022; 364:109519. [PMID: 35032935 DOI: 10.1016/j.ijfoodmicro.2021.109519] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 12/13/2021] [Accepted: 12/28/2021] [Indexed: 11/21/2022]
Abstract
This study aims to quantify growth and cereulide production by Bacillus cereus and their potential correlation in an intermediate dairy wet-mix. Systematic experiments were carried out using the emetic reference strain F4810/72 in the suboptimal range of temperature of 12 °C to 20 °C. Growth and cereulide kinetic parameters were estimated and the three parameters (i) time to first cereulide quantification (tcer), (ii) maximum specific growth rates (μmax) and (iii) cereulide production rates (k) were modelled as a function of temperature. As temperature increased, growth lag time and tcer were shorter while microbial increase and cereulide production happened earlier, and at higher rates. Maximum concentration of cells and maximum cereulide concentration proved to be temperature-independent, reaching the average values of 7.9 ± 0.3 log10(CFU/mL) and 2.6 ± 0.2 log10(ng.g-1) respectively. Moreover, the time to reach the widely used threshold of 5 log10CFU/mL (t5log) was tested against tcer, and this suggested that this threshold can be used with increased confidence at lower temperatures to assure toxin is not quantified in this matrix. The average tcer were equal to 314 h, 118 h, 73 h and 45 h for 12 °C, 15 °C, 18 °C and 20 °C respectively. A validation study was performed using independent data sets obtained with the same strain in other dairy matrices. The microbial growth models presented good predictive power even when extrapolated beyond the temperature range of construction. Nevertheless, the models proposed for prediction of toxin production over time presented limitations, especially for food matrices that deviate significantly from the original matrix for which the model was developed, making cereulide predictions less accurate. Our findings suggest that similar modelling approaches can be used to predict growth, time to first cereulide quantification as well as cereulide formation over time for a specific matrix, but that matrix-extrapolations are more suitable for growth than for cereulide.
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18
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Sun R, Vermeulen A, Wieme AD, Vandamme P, Devlieghere F. Identification and characterization of acid-tolerant spore-forming spoilage bacteria from acidified and low-acid pasteurized sauces. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.112378] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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19
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Park KM, Kim HJ, Choi JY, Koo M. Antimicrobial Effect of Acetic Acid, Sodium Hypochlorite, and Thermal Treatments against Psychrotolerant Bacillus cereus Group Isolated from Lettuce ( Lactuca sativa L.). Foods 2021; 10:foods10092165. [PMID: 34574273 PMCID: PMC8467346 DOI: 10.3390/foods10092165] [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: 08/13/2021] [Revised: 09/01/2021] [Accepted: 09/10/2021] [Indexed: 11/20/2022] Open
Abstract
Various food products distributed throughout the cold chain can present a health risk for consumers due to the presence of psychrotolerant B. cereus group species that possess enterotoxin genes and antibiotic resistance. As these bacteria can grow at the low temperatures used in the food industry, this study evaluated the antimicrobial efficacy of acetic acid, sodium hypochlorite, and thermal treatments for inhibition of psychrotolerant strains and the effect that differences in activation temperature (30 °C and 10 °C) have on their efficacy. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bacterial growth assay of acetic acid and thermal treatment showed an equal or higher antimicrobial efficacy in isolates activated at 10 °C than in those activated at 30 °C. In particular, psychrotolerant strains from the B. cereus group were completely eliminated with 0.25% acetic acid, regardless of the activation temperature. The possibility of tolerance was determined by observing responses in cells activated at 10 and 30 °C when exposed to different concentrations of sodium hypochlorite. Five isolates activated at 10 °C exhibited enhanced survivability in sodium hypochlorite compared to isolates activated at 30 °C, and these isolates were able to grow in sodium hypochlorite at concentrations of 250 ppm or higher. Although a significant difference in antimicrobial efficacy was observed for psychrotolerant B. cereus group strains depending on the activation temperature, acetic acid may be the most effective antimicrobial agent against psychrotolerant B. cereus species isolated from food products distributed in a cold chain.
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Affiliation(s)
- Kyung-Min Park
- Department of Food Analysis Center, Korea Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea; (K.-M.P.); (J.-Y.C.)
| | - Hyun-Jung Kim
- Department of Research Group of Consumer Safety, Korea Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea;
- Food Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon 34113, Korea
| | - Ji-Yoen Choi
- Department of Food Analysis Center, Korea Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea; (K.-M.P.); (J.-Y.C.)
| | - Minseon Koo
- Department of Food Analysis Center, Korea Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea; (K.-M.P.); (J.-Y.C.)
- Food Biotechnology, University of Science and Technology (UST), Yuseong-gu, Daejeon 34113, Korea
- Correspondence: ; Tel.: +82-63-219-9161
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20
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Lim ES, Baek SY, Oh T, Koo M, Lee JY, Kim HJ, Kim JS. Strain variation in Bacillus cereus biofilms and their susceptibility to extracellular matrix-degrading enzymes. PLoS One 2021; 16:e0245708. [PMID: 34133441 PMCID: PMC8208538 DOI: 10.1371/journal.pone.0245708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 06/02/2021] [Indexed: 01/25/2023] Open
Abstract
Bacillus cereus is a foodborne pathogen and can form biofilms on food contact surfaces, which causes food hygiene problems. While it is necessary to understand strain-dependent variation to effectively control these biofilms, strain-to-strain variation in the structure of B. cereus biofilms is poorly understood. In this study, B. cereus strains from tatsoi (BC4, BC10, and BC72) and the ATCC 10987 reference strain were incubated at 30°C to form biofilms in the presence of the extracellular matrix-degrading enzymes DNase I, proteinase K, dispase II, cellulase, amyloglucosidase, and α-amylase to assess the susceptibility to these enzymes. The four strains exhibited four different patterns in terms of biofilm susceptibility to the enzymes as well as morphology of surface-attached biofilms or suspended cell aggregates. DNase I inhibited the biofilm formation of strains ATCC 10987 and BC4 but not of strains BC10 and BC72. This result suggests that some strains may not have extracellular DNA, or their extracellular DNA may be protected in their biofilms. In addition, the strains exhibited different patterns of susceptibility to protein- and carbohydrate-degrading enzymes. While other strains were resistant, strains ATCC 10987 and BC4 were susceptible to cellulase, suggesting that cellulose or its similar polysaccharides may exist and play an essential role in their biofilm formation. Our compositional and imaging analyses of strains ATCC 10987 and BC4 suggested that the physicochemical properties of their biofilms are distinct, as calculated by the carbohydrate to protein ratio. Taken together, our study suggests that the extracellular matrix of B. cereus biofilms may be highly diverse and provides insight into the diverse mechanisms of biofilm formation among B. cereus strains.
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Affiliation(s)
- Eun Seob Lim
- Department of Food Biotechnology, Korea University of Science and Technology, Yuseong-gu, Daejeon, Republic of Korea
- Research Group of Consumer Safety, Research Division of Strategic Food Technology, Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea
| | - Seung-Youb Baek
- Research Group of Consumer Safety, Research Division of Strategic Food Technology, Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea
| | - Taeyoung Oh
- Research Group of Consumer Safety, Research Division of Strategic Food Technology, Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea
| | - Minseon Koo
- Department of Food Biotechnology, Korea University of Science and Technology, Yuseong-gu, Daejeon, Republic of Korea
- Food Analysis Center, Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea
| | - Joo Young Lee
- Research Group of Consumer Safety, Research Division of Strategic Food Technology, Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea
- Department of Food Science and Biotechnology, Sungkyunkwan University, Jangan-gu, Suwon, Republic of Korea
| | - Hyun Jung Kim
- Department of Food Biotechnology, Korea University of Science and Technology, Yuseong-gu, Daejeon, Republic of Korea
- Research Group of Consumer Safety, Research Division of Strategic Food Technology, Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea
- * E-mail: (HJK); (JSK)
| | - Joo-Sung Kim
- Department of Food Biotechnology, Korea University of Science and Technology, Yuseong-gu, Daejeon, Republic of Korea
- Research Group of Consumer Safety, Research Division of Strategic Food Technology, Korea Food Research Institute, Wanju-gun, Jeollabuk-do, Republic of Korea
- * E-mail: (HJK); (JSK)
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21
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Park KM, Kim HJ, Kim MS, Koo M. Morphological Features and Cold-Response Gene Expression in Mesophilic Bacillus cereus Group and Psychrotolerant Bacillus cereus Group under Low Temperature. Microorganisms 2021; 9:microorganisms9061255. [PMID: 34207706 PMCID: PMC8229767 DOI: 10.3390/microorganisms9061255] [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: 05/05/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 11/27/2022] Open
Abstract
At low temperatures, psychrotolerant B. cereus group strains exhibit a higher growth rate than mesophilic strains do. However, the different survival responses of the psychrotolerant strain (BCG34) and the mesophilic strain (BCGT) at low temperatures are unclear. We investigated the morphological and genomic features of BCGT and BCG34 to characterize their growth strategies at low temperatures. At low temperatures, morphological changes were observed only in BCGT. These morphological changes included the elongation of rod-shaped cells, whereas the cell shape in BCG34 was unchanged at the low temperature. A transcriptomic analysis revealed that both species exhibited different growth-related traits during low-temperature growth. The BCGT strain induces fatty acid biosynthesis, sulfur assimilation, and methionine and cysteine biosynthesis as a survival mechanism in cold systems. Increases in energy metabolism and fatty acid biosynthesis in the mesophilic B. cereus group strain might explain its ability to grow at low temperatures. Several pathways involved in carbohydrate mechanisms were downregulated to conserve the energy required for growth. Peptidoglycan biosynthesis was upregulated, implying that a change of gene expression in both RNA-Seq and RT-qPCR contributed to sustaining its growth and rod shape at low temperatures. These results improve our understanding of the growth response of the B. cereus group, including psychrotolerant B. cereus group strains, at low temperatures and provide information for improving bacterial inhibition strategies in the food industry.
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Affiliation(s)
- Kyung-Min Park
- Department of Food Analysis Center, Korea Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea; (K.-M.P.); (M.-S.K.)
| | - Hyun-Jung Kim
- Research Group of Consumer Safety, Korea Food Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea;
- Department of Food Biotechnology, Korea University of Science & Technology, Daejeon 34113, Korea
| | - Min-Sun Kim
- Department of Food Analysis Center, Korea Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea; (K.-M.P.); (M.-S.K.)
| | - Minseon Koo
- Department of Food Analysis Center, Korea Research Institute, Wanju-gun 55365, Jeollabuk-do, Korea; (K.-M.P.); (M.-S.K.)
- Department of Food Biotechnology, Korea University of Science & Technology, Daejeon 34113, Korea
- Correspondence:
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22
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Incidence, toxin gene profiling, antimicrobial susceptibility, and genetic diversity of Bacillus cereus isolated from quick-frozen food in China. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2020.110824] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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23
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Kong L, Yu S, Yuan X, Li C, Yu P, Wang J, Guo H, Wu S, Ye Q, Lei T, Yang X, Zhang Y, Wei X, Zeng H, Zhang J, Wu Q, Ding Y. An Investigation on the Occurrence and Molecular Characterization of Bacillus cereus in Meat and Meat Products in China. Foodborne Pathog Dis 2021; 18:306-314. [PMID: 33769083 DOI: 10.1089/fpd.2020.2885] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Bacillus cereus is a common foodborne pathogen that can cause both gastrointestinal and nongastrointestinal diseases. In this study, we collected 603 meat and meat products from 39 major cities in China. The positive contamination rate of B. cereus in the collected samples was 26.37% (159/603), and the contamination level in 5.03% (8/159) positive samples exceeded 1100 most probable number/g. The detection rates of virulence genes were 89.7% for the nheABC gene group, 37.1% for the hblACD gene cluster, 82.3% for cytK-2, and 2.9% for cesB. Notably, all isolates presented with multiple antibiotic resistance, and 99.43% of isolates were resistant to five classes of antibiotics. In addition, the multilocus sequence typing results indicated that all isolates were rich in genetic diversity. Collectively, we conducted a systematic investigation on the prevalence and characterization of B. cereus in meat and meat products in China, providing crucial information for assessing the risk of B. cereus occurrence in meat and meat products.
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Affiliation(s)
- Li Kong
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China.,Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
| | - Shubo Yu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xiaoming Yuan
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China.,Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
| | - Chun Li
- Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
| | - Pengfei Yu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China.,Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Hui Guo
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China.,Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
| | - Shi Wu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Qinghua Ye
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Tao Lei
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xiaojuan Yang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Youxiong Zhang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Xianhu Wei
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Haiyan Zeng
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Jumei Zhang
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Qingping Wu
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China
| | - Yu Ding
- Guangdong Provincial Key Laboratory of Microbial Safety and Health, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, China.,Department of Food Science and Technology, Institute of Food Safety and Nutrition, Jinan University, Guangzhou, China
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Prevalence, toxigenic profiles, multidrug resistance, and biofilm formation of Bacillus cereus isolated from ready-to eat cooked rice in Penang, Malaysia. Food Control 2021. [DOI: 10.1016/j.foodcont.2020.107553] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Jessberger N, Dietrich R, Granum PE, Märtlbauer E. The Bacillus cereus Food Infection as Multifactorial Process. Toxins (Basel) 2020; 12:E701. [PMID: 33167492 PMCID: PMC7694497 DOI: 10.3390/toxins12110701] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023] Open
Abstract
The ubiquitous soil bacterium Bacillus cereus presents major challenges to food safety. It is responsible for two types of food poisoning, the emetic form due to food intoxication and the diarrheal form emerging from food infections with enteropathogenic strains, also known as toxico-infections, which are the subject of this review. The diarrheal type of food poisoning emerges after production of enterotoxins by viable bacteria in the human intestine. Basically, the manifestation of the disease is, however, the result of a multifactorial process, including B. cereus prevalence and survival in different foods, survival of the stomach passage, spore germination, motility, adhesion, and finally enterotoxin production in the intestine. Moreover, all of these processes are influenced by the consumed foodstuffs as well as the intestinal microbiota which have, therefore, to be considered for a reliable prediction of the hazardous potential of contaminated foods. Current knowledge regarding these single aspects is summarized in this review aiming for risk-oriented diagnostics for enteropathogenic B. cereus.
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Affiliation(s)
- Nadja Jessberger
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
| | - Richard Dietrich
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
| | - Per Einar Granum
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, P.O. Box 5003 NMBU, 1432 Ås, Norway;
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
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26
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Tran SL, Cormontagne D, Vidic J, André-Leroux G, Ramarao N. Structural Modeling of Cell Wall Peptidase CwpFM (EntFM) Reveals Distinct Intrinsically Disordered Extensions Specific to Pathogenic Bacillus cereus Strains. Toxins (Basel) 2020; 12:toxins12090593. [PMID: 32937845 PMCID: PMC7551459 DOI: 10.3390/toxins12090593] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/04/2020] [Accepted: 09/09/2020] [Indexed: 12/21/2022] Open
Abstract
The emergence of B. cereus as an opportunistic food-borne pathogen has intensified the need to distinguish strains of public health concern. The heterogeneity of the diseases associated with B. cereus infections emphasizes the versatility of these bacteria strains to colonize their host. Nevertheless, the molecular basis of these differences remains unclear. Several toxins are involved in virulence, particularly in gastrointestinal disorders, but there are currently no biological markers able to differentiate pathogenic from harmless strains. We have previously shown that CwpFM is a cell wall peptidase involved in B. cereus virulence. Here, we report a sequence/structure/function characterization of 39 CwpFM sequences, chosen from a collection of B. cereus with diverse virulence phenotypes, from harmless to highly pathogenic strains. CwpFM is homology-modeled in silico as an exported papain-like endopeptidase, with an N-terminal end composed of three successive bacterial Src Homology 3 domains (SH3b1–3) likely to control protein–protein interactions in signaling pathways, and a C-terminal end that contains a catalytic NLPC_P60 domain primed to form a competent active site. We confirmed in vitro that CwpFM is an endopeptidase with a moderate peptidoglycan hydrolase activity. Remarkably, CwpFMs from pathogenic strains harbor a specific stretch of twenty residues intrinsically disordered, inserted between the SH3b3 and the catalytic NLPC_P60 domain. This strongly suggests this linker as a marker of differentiation between B. cereus strains. We believe that our findings improve our understanding of the pathogenicity of B. cereus while advancing both clinical diagnosis and food safety.
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Affiliation(s)
- Seav-Ly Tran
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (D.C.); (J.V.)
| | - Delphine Cormontagne
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (D.C.); (J.V.)
| | - Jasmina Vidic
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (D.C.); (J.V.)
| | - Gwenaëlle André-Leroux
- MaIAGE, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France
- Correspondence: (G.A.-L.); (N.R.)
| | - Nalini Ramarao
- Micalis Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (S.-L.T.); (D.C.); (J.V.)
- Correspondence: (G.A.-L.); (N.R.)
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