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Guan P, Fan S, Dong W, Wang X, Li Z, Song M, Suo B. Comparative genomic analysis and multilocus sequence typing of Staphylococcus aureus reveals candidate genes for low-temperature tolerance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171331. [PMID: 38428609 DOI: 10.1016/j.scitotenv.2024.171331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/23/2024] [Accepted: 02/26/2024] [Indexed: 03/03/2024]
Abstract
Staphylococcus aureus is one of the most frequently detected foodborne pathogens in cold chain foods. Worryingly, small colony variants (SCVs) can survive in cold environments for a long time and can revert to rapidly growing cells in suitable environments, causing serious food safety issues. This study investigated the underlying mechanism of SCV formation at low temperature (4 °C) via comparative genomics. Multilocus sequence typing (MLST) of 105 strains of S. aureus was divided into 9 sequence types. The ST352 strains exhibited the greatest tolerance to low temperature, with a mean reduction in survival rate of 10.34 % (p < 0.05). Comparative genomics revealed a total of 1941 core genes in the three S. aureus strains, and BB-1 had 468 specific genes, which were enriched mainly in translation, DNA recombination, DNA repair, metabolic pathways, two-component systems, and quorum sensing. Molecular docking analysis revealed that the binding of the RsbW protein to the SigB protein of BB-1 decreased due to base mutations in rsbW, while the binding to the RsbV protein was enhanced. In addition, the results of real-time quantitative PCR showed that the RsbV-RsbW/SigB system of BB-1 may play a role in the low-temperature survival of S. aureus and the formation of SCVs. These results suggest that genes specific to BB-1 may contribute to the mechanism of adaptation to low temperature and the formation of SCVs. This study helps elucidate the causes of SCV formation by S. aureus at low temperature at the molecular level and provides a basis for exploring the safety control of cold chain food environments.
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Affiliation(s)
- Peng Guan
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China
| | - Shijia Fan
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China
| | - Wenjing Dong
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China
| | - Xiaojie Wang
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China; Key Laboratory of Staple Grain Processing, Ministry of Agriculture and Rural Affairs, Zhengzhou, China; National R&D Center for Frozen Rice & Wheat Products Processing Technology, Henan Engineering Laboratory of Quick-Frozen Flour-Rice Food and Prepared Food, Henan Agricultural University, Zhengzhou, China
| | - Zhen Li
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China; Key Laboratory of Staple Grain Processing, Ministry of Agriculture and Rural Affairs, Zhengzhou, China; National R&D Center for Frozen Rice & Wheat Products Processing Technology, Henan Engineering Laboratory of Quick-Frozen Flour-Rice Food and Prepared Food, Henan Agricultural University, Zhengzhou, China
| | - Miao Song
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China; Key Laboratory of Staple Grain Processing, Ministry of Agriculture and Rural Affairs, Zhengzhou, China; National R&D Center for Frozen Rice & Wheat Products Processing Technology, Henan Engineering Laboratory of Quick-Frozen Flour-Rice Food and Prepared Food, Henan Agricultural University, Zhengzhou, China
| | - Biao Suo
- College of Food Science and Technology, Henan Agricultural University, Zhengzhou, China; Key Laboratory of Staple Grain Processing, Ministry of Agriculture and Rural Affairs, Zhengzhou, China; National R&D Center for Frozen Rice & Wheat Products Processing Technology, Henan Engineering Laboratory of Quick-Frozen Flour-Rice Food and Prepared Food, Henan Agricultural University, Zhengzhou, China.
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Cha X, Lin Y, Brennan C, Cao J, Shang Y. Antibiotic Resistance of Bacillus cereus in Plant Foods and Edible Wild Mushrooms in a Province. Microorganisms 2023; 11:2948. [PMID: 38138092 PMCID: PMC10745370 DOI: 10.3390/microorganisms11122948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/24/2023] Open
Abstract
Bacillus cereus is a common pathogen causing foodborne diseases, secreting and producing a large number of toxins that can cause a variety of diseases and pose many threats to human health. In this study, 73 strains of Bacillus cereus were isolated and identified from six types of foods from seven different cities in a province, and the antibiotic-resistant phenotype was detected by using the Bauer-Kirby method. Results showed that the 73 isolates were completely sensitive to gentamicin and 100% resistant to chloramphenicol, in addition to which all strains showed varying degrees of resistance to 13 other common antibiotics, and a large number of strains resistant to multiple antibiotics were found. A bioinformatic analysis of the expression of resistance genes in Bacillus cereus showed three classes of antibiotic-resistant genes, which were three of the six classes of antibiotics identified according to the resistance phenotype. The presence of other classes of antibiotic-resistant genes was identified from genome-wide information. Antibiotic-resistant phenotypes were analyzed for correlations with genotype, and remarkable differences were found among the phenotypes. The spread of antibiotic-resistant strains is a serious public health problem that requires the long-term monitoring of antimicrobial resistance in Bacillus cereus, and the present study provides important information for monitoring antibiotic resistance in bacteria from different types of food.
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Affiliation(s)
- Xiaoyan Cha
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (X.C.); (Y.L.); (C.B.)
| | - Yingting Lin
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (X.C.); (Y.L.); (C.B.)
| | - Charles Brennan
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (X.C.); (Y.L.); (C.B.)
- School of Science, Royal Melbourne Institute of Technology University, Melbourne 3000, Australia
| | - Jianxin Cao
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (X.C.); (Y.L.); (C.B.)
| | - Ying Shang
- Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; (X.C.); (Y.L.); (C.B.)
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Oliveira M, Carvalho M, Teixeira P. Characterization of the Toxigenic Potential of Bacillus cereus sensu lato Isolated from Raw Berries and Their Products. Foods 2023; 12:4021. [PMID: 37959140 PMCID: PMC10648475 DOI: 10.3390/foods12214021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 10/29/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023] Open
Abstract
Bacillus cereus is estimated to be responsible for 1.4-12% of all food poisoning outbreaks worldwide. The objective of this study was to investigate the toxigenic potential of 181 isolates of B. cereus previously recovered from different types of berries and berry products (strawberries, raspberries, blackberries, and blueberries) by assessing the presence of enterotoxin genes (hblA, hblC, hblD, nheA, nheB, nheC, and cytK) and an emetic toxin cereulide synthetase gene (ces). The cytotoxic activity on Caco-2 cells was also evaluated for the two isolates containing the gene cytK. Twenty-three toxigenic profiles were found. The nheABC (91.7%) and hblACD (89.0%) complexes were the most prevalent among the isolates, while the cytK and ces genes were detected in low percentages, 1.1% and 3.3%, respectively. In addition, the nheABC/hblACD complex and ces genes were detected in isolates recovered throughout the production process of blackberries and strawberries. The cytotoxic activity on Caco-2 cells was also observed to be greater than 60% for isolates containing the cytK gene.
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Affiliation(s)
- Márcia Oliveira
- Department of Food Hygiene and Technology, University of León, 24071 León, Spain;
| | - Marta Carvalho
- Laboratório Associado, CBQF—Centro de Biotecnologia e Química Fina, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal;
| | - Paula Teixeira
- Laboratório Associado, CBQF—Centro de Biotecnologia e Química Fina, Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal;
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Li Q, Li C, Chen L, Cai Z, Wu S, Gu Q, Zhang Y, Wei X, Zhang J, Yang X, Zhang S, Ye Q, Wu Q. Cronobacter spp. Isolated from Quick-Frozen Foods in China: Incidence, Genetic Characteristics, and Antibiotic Resistance. Foods 2023; 12:3019. [PMID: 37628018 PMCID: PMC10453260 DOI: 10.3390/foods12163019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Cronobacter spp. are emerging foodborne pathogens that cause severe diseases. However, information on Cronobacter contamination in quick-frozen foods in China is limited. Therefore, we studied the prevalence, molecular characterization, and antimicrobial susceptibility of Cronobacter in 576 quick-frozen food samples collected from 39 cities in China. Cronobacter spp. were found in 18.75% (108/576) of the samples, and the contamination degree of the total positive samples was 5.82 MPN/g. The contamination level of frozen flour product samples was high (44.34%). Among 154 isolates, 109 were C. sakazakii, and the main serotype was C. sakazakii O1 (44/154). Additionally, 11 serotypes existed among four species. Eighty-five sequence types (STs), including 22 novel ones, were assigned, indicating a relatively high genetic diversity of the Cronobacter in this food type. Pathogenic ST148, ST7, and ST1 were the main STs in this study. ST4, epidemiologically related to neonatal meningitis, was also identified. All strains were sensitive to cefepime, tobramycin, ciprofloxacin, and imipenem, in which the resistance to cephalothin was the highest (64.94%).Two isolates exhibited multidrug resistance to five and seven antimicrobial agents, respectively. In conclusion, these findings suggest that the comparatively high contamination level of Cronobacter spp. in quick-frozen foods is a potential risk warranting public attention.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Qingping Wu
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), 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 510070, China; (Q.L.); (C.L.); (L.C.); (Z.C.); (S.W.); (Q.G.); (Y.Z.); (X.W.); (J.Z.); (X.Y.); (S.Z.); (Q.Y.)
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Detection of emetic Bacillus cereus and the emetic toxin cereulide in food matrices: Progress and perspectives. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.03.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Differentiation of Bacillus cereus and Bacillus thuringiensis Using Genome-Guided MALDI-TOF MS Based on Variations in Ribosomal Proteins. Microorganisms 2022; 10:microorganisms10050918. [PMID: 35630362 PMCID: PMC9146703 DOI: 10.3390/microorganisms10050918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 12/10/2022] Open
Abstract
Bacillus cereus and B. thuringiensis are closely related species that are relevant to foodborne diseases and biopesticides, respectively. Unambiguous differentiation of these two species is crucial for bacterial taxonomy. As genome analysis offers an objective but time-consuming classification of B. cereus and B. thuringiensis, in the present study, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was used to accelerate this process. By combining in silico genome analysis and MALDI-TOF MS measurements, four species-specific peaks of B. cereus and B. thuringiensis were screened and identified. The species-specific peaks of B. cereus were m/z 3211, 6427, 9188, and 9214, and the species-specific peaks of B. thuringiensis were m/z 3218, 6441, 9160, and 9229. All the above peaks represent ribosomal proteins, which are conserved and consistent with the phylogenetic relationship between B. cereus and B. thuringiensis. The specificity of the peaks was robustly verified using common foodborne pathogens. Thus, we concluded that genome-guided MALDI-TOF MS allows high-throughput differentiation of B. cereus and B. thuringiensis and provides a framework for differentiating other closely related species.
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Etikala A, Thamburaj S, Johnson AM, Sarma C, Mummaleti G, Kalakandan SK. Incidence, toxin gene profile, antibiotic resistance and antibacterial activity of Allium parvum and Allium cepa extracts on Bacillus cereus isolated from fermented millet-based food. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.113314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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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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Zhou H, Zhang J, Shao Y, Wang J, Xu W, Liu Y, Yu S, Ye Q, Pang R, Wu S, Gu Q, Xue L, Zhang J, Li H, Wu Q, Ding Y. Development of a high resolution melting method based on a novel molecular target for discrimination between Bacillus cereus and Bacillus thuringiensis. Food Res Int 2022; 151:110845. [PMID: 34980383 DOI: 10.1016/j.foodres.2021.110845] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 11/03/2021] [Accepted: 11/27/2021] [Indexed: 11/04/2022]
Abstract
Delimitation within the Bacillus cereus group is confusing due to the highly similar genetic background of its constituent bacteria. This study aimed to develop a rapid and efficient method for the identification of Bacillus cereus and Bacillus thuringiensis, two closely related species within the B. cereus group. Using average nucleotide identity analysis (ANI) and ribosomal multilocus sequence typing (rMLST), the authenticity of the genomes of B. cereus and B. thuringiensis was determined. Emetic B. cereus and Bacillus bombysepticus were also included to provide novel genomic insights into the boundaries within the B. cereus group. Using pan-genome analysis, ispD, a novel core and single-copy molecular target, was identified for the differentiation between B. cereus and B. thuringiensis. Based on the single nucleotide polymorphism within ispD, a high resolution melting (HRM) method for the determination of B. cereus and B. thuringiensis was developed. This method can not only distinguish B. cereus and B. thuringiensis, but can also separate B. cereus from other foodborne pathogenic bacteria. The detection limit of this method could reach 1 pg of pure genomic DNA and 3.7 × 102 cfu/mL of pure culture. Moreover, this new method could effectively differentiate B. cereus and B. thuringiensis in spiked, mixed, and real food samples. Collectively, the established HRM method can provide a new reference paradigm for the sensitive and specific nucleic acid detection of pathogens with identical genomes.
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Affiliation(s)
- Huan Zhou
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; 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 510070, China
| | - Junhui Zhang
- Department of Food Science & Technology, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; 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 510070, China
| | - Yanna Shao
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Department of Food Science & Technology, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; 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 510070, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou 510432, China
| | - Wenxing Xu
- Department of Food Science & Technology, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; 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 510070, China
| | - Yang Liu
- 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 510070, 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 510070, 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 510070, China
| | - Rui Pang
- 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 510070, 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 510070, China
| | - Qihui Gu
- 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 510070, China
| | - Liang Xue
- 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 510070, 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 510070, China
| | - Hongye Li
- College of Life Science and Technology, Jinan University, Guangzhou 510632, 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 510070, China
| | - Yu Ding
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Department of Food Science & Technology, Institute of Food Safety & Nutrition, Jinan University, Guangzhou 510632, China; 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 510070, China.
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