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Imm S, Chang Y. Evaluation of the biocontrol potential of a collagen peptide/trehalose-based Cronobacter sakazakii phage powder in rehydrated powdered infant formula. Food Res Int 2023; 173:113257. [PMID: 37803569 DOI: 10.1016/j.foodres.2023.113257] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 07/06/2023] [Accepted: 07/07/2023] [Indexed: 10/08/2023]
Abstract
Cronobacter sakazakii is a major foodborne pathogen that is mainly transmitted through powdered infant formula (PIF) and has a high mortality rate of up to 80%, particularly in fetuses and neonates. Bacteriophages have emerged as an effective biocontrol agent for antibiotic-resistant bacteria. In this study, lytic phage SG01 was newly characterized and loaded into collagen peptide/trehalose-based powders to develop an antibacterial agent against C. sakazakii contamination in PIF. The phage belongs to the Siphoviridae family, has an icosahedral head and a flexible tail, and showed rapid and persistent antibacterial activity up to 17 h. It was specifically active against C. sakazakii and also exhibited effective anti-biofilm properties. The phage was freeze-dried to a collagen peptide/trehalose-based powder and the phage was tested for viability, storage stability, and antibacterial activity. The optimal composition was 5% (w/v) collagen peptides and 1% (w/v) trehalose, which demonstrated the highest phage viability after freeze-drying. The phage remained stable in the collagen peptide/trehalose-based powder for up to four weeks at 4 °C and 25 °C, indicating that this is a desirable formulation for phage protection. Furthermore, the phage powder showed significant antibacterial efficacy in PIF, with a 4-log CFU/mL reduction within 6 h. Overall, the tested phage powder has the potential to be used as an antimicrobial agent in the food industry, particularly in powdered foods such as PIF.
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Affiliation(s)
- Seulgi Imm
- Department of Food and Nutrition, College of Science and Technology, Kookmin University, Seoul 02707, Republic of Korea.
| | - Yoonjee Chang
- Department of Food and Nutrition, College of Science and Technology, Kookmin University, Seoul 02707, Republic of Korea.
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2
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Xu J, Wang Y, Liu F, Duan G, Yang H. Genome mining reveals the prevalence and extensive diversity of toxin-antitoxin systems in Staphylococcus aureus. Front Microbiol 2023; 14:1165981. [PMID: 37293231 PMCID: PMC10244574 DOI: 10.3389/fmicb.2023.1165981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/28/2023] [Indexed: 06/10/2023] Open
Abstract
Introduction Staphylococcus aureus (S. aureus) is a highly pathogenic and adaptable Gram-positive bacterium that exhibits persistence in various environments. The toxin-antitoxin (TA) system plays a crucial role in the defense mechanism of bacterial pathogens, allowing them to survive in stressful conditions. While TA systems in clinical pathogens have been extensively studied, there is limited knowledge regarding the diversity and evolutionary complexities of TA systems in S. aureus. Methods We conducted a comprehensive in silico survey using 621 publicly available S. aureus isolates. We employed bioinformatic search and prediction tools, including SLING, TADB2.0, and TASmania, to identify TA systems within the genomes of S. aureus. Results Our analysis revealed a median of seven TA systems per genome, with three type II TA groups (HD, HD_3, and YoeB) being present in over 80% of the strains. Additionally, we observed that TA genes were predominantly encoded in the chromosomal DNA, with some TA systems also found within the Staphylococcal Cassette Chromosomal mec (SCCmec) genomic islands. Discussion This study provides a comprehensive overview of the diversity and prevalence of TA systems in S. aureus. The findings enhance our understanding of these putative TA genes and their potential implications in S. aureus ecology and disease management. Moreover, this knowledge could guide the development of novel antimicrobial strategies.
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Mousavi ZE, Hunt K, Koolman L, Butler F, Fanning S. Cronobacter Species in the Built Food Production Environment: A Review on Persistence, Pathogenicity, Regulation and Detection Methods. Microorganisms 2023; 11:1379. [PMID: 37374881 DOI: 10.3390/microorganisms11061379] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/17/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
The powdered formula market is large and growing, with sales and manufacturing increasing by 120% between 2012 and 2021. With this growing market, there must come an increasing emphasis on maintaining a high standard of hygiene to ensure a safe product. In particular, Cronobacter species pose a risk to public health through their potential to cause severe illness in susceptible infants who consume contaminated powdered infant formula (PIF). Assessment of this risk is dependent on determining prevalence in PIF-producing factories, which can be challenging to measure with the heterogeneity observed in the design of built process facilities. There is also a potential risk of bacterial growth occurring during rehydration, given the observed persistence of Cronobacter in desiccated conditions. In addition, novel detection methods are emerging to effectively track and monitor Cronobacter species across the food chain. This review will explore the different vehicles that lead to Cronobacter species' environmental persistence in the food production environment, as well as their pathogenicity, detection methods and the regulatory framework surrounding PIF manufacturing that ensures a safe product for the global consumer.
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Affiliation(s)
- Zeinab Ebrahimzadeh Mousavi
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, D04 V1W8 Dublin, Ireland
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Dublin 4, D04 V1W8 Dublin, Ireland
- Department of Food Science and Engineering, Faculties of Agriculture and Natural Resources, University of Tehran, Karaj 6719418314, Iran
| | - Kevin Hunt
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Dublin 4, D04 V1W8 Dublin, Ireland
| | - Leonard Koolman
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Francis Butler
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Dublin 4, D04 V1W8 Dublin, Ireland
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, D04 V1W8 Dublin, Ireland
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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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5
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Zhong H, Deng H, Li M, Zhong H. Bioprocessing and integration of a high flux screening systematic platform based on isothermal amplification for the detection on 8 common pathogens. Bioprocess Biosyst Eng 2021; 44:977-984. [PMID: 32862325 PMCID: PMC8096746 DOI: 10.1007/s00449-020-02423-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 08/05/2020] [Indexed: 11/23/2022]
Abstract
During a large variety of common pathogens, E. coli, P. aeruginosa, MRSA, MRCNS, V. parahaemolyticus, L. monocytogenes and Salmonella are the leading pathogens responsible for large number of human infections and diseases. In this study, a high flux screening based on nucleic acid isothermal amplification technique has been developed. For the 8 common pathogens, species-specific targets had been selected and analyzed for their unique specificity. After optimization, separate LAMP reaction assays had been bioprocessed and integrated into one systematic detection platform, including 8 strips (PCR tubes) and 96-well plates. Eight standard strains verified for the accuracy. Application of the established high flux screening platform was used for detection for 48 samples in 4 different 96-well plates, with 2 groups of 2 operators using double-blind procedure. The accuracy of 100% was obtained, with the total time consumption as 66-75 min (for 12 samples detection on 8 different pathogens). As concluded, through the bioprocess of the systematic platform based on LAMP technique, it's been demonstrated to be capable of simultaneous detection of 8 pathogens, with high sensitivity, specificity, rapidity and convenience.
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Affiliation(s)
- Huamin Zhong
- Department of Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510120, China
| | - Hongwei Deng
- Shenzhen Key Laboratory of Ophthalmology, Ocular Trauma Treatment and Stem Cell Differentiation Public Service Platform of Shenzhen, Shenzhen Eye Hospital, Shenzhen, 518040, China
| | - Ming Li
- Shenzhen Key Laboratory of Ophthalmology, Ocular Trauma Treatment and Stem Cell Differentiation Public Service Platform of Shenzhen, Shenzhen Eye Hospital, Shenzhen, 518040, China
| | - Huahong Zhong
- Shenzhen Key Laboratory of Ophthalmology, Ocular Trauma Treatment and Stem Cell Differentiation Public Service Platform of Shenzhen, Shenzhen Eye Hospital, Shenzhen, 518040, China.
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Li Y, Qiu Y, Ye C, Chen L, Liang Y, Huang TY, Zhang L, Liu J. "One-step" characterization platform for pathogenic genetics of Staphylococcus aureus. Bioprocess Biosyst Eng 2021; 44:985-994. [PMID: 33112989 DOI: 10.1007/s00449-020-02449-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 09/14/2020] [Indexed: 02/05/2023]
Abstract
Staphylococcus aureus (S. aureus) is an important human pathogen causing a variety of life-threatening diseases. In recent years, the health problem caused by S. aureus contaminated food has become a global health problem. S. aureus can express various pathogenic factors, mainly used for adhesion, colonization, invasion and infection of the host. Therefore, rapid and accurate detection of virulence genes in S. aureus is necessary to prevent outbreaks caused by this pathogen. PCR is a useful tool for rapid detection of foodborne pathogens. The objective of this study was to detect the presence of major toxin genes in S. aureus, including sea, seb, sec, see, pvl and tsst, by using a PCR plate. Of the 13 strains tested, 12 (92.3%) were found to be positive for one or more toxin genes. This study realized the one-step detection of main toxin factors in S. aureus.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China
| | - Yisen Qiu
- Department of Spine Surgery, The Second Affiliated Hospital of Shantou University Medical College, North Dongxia Road, Shantou, 515041, Guangdong, China
| | - Congxiu Ye
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510640, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Yi Liang
- Guangdong Zhongqing Font Biochemical Science and Technology Co. Ltd., Maoming, 525427, Guangdong, China
| | - Teng-Yi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China
| | - Li Zhang
- Department of Haematology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China
| | - Junyan Liu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China.
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7
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Xu Z, Liu Z, Soteyome T, Hua J, Zhang L, Yuan L, Ye Y, Cai Z, Yang L, Chen L, Harro JM, Kjellerup BV, Liu J, Li Y. Impact of pmrA on Cronobacter sakazakii planktonic and biofilm cells: A comprehensive transcriptomic study. Food Microbiol 2021; 98:103785. [PMID: 33875213 DOI: 10.1016/j.fm.2021.103785] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 12/30/2020] [Accepted: 03/05/2021] [Indexed: 10/21/2022]
Abstract
Cronobacter sakazakii is an emerging opportunistic foodborne pathogen causing rare but severe infections in neonates. Furthermore, the formation of biofilm allows C. sakazakii to persist in different environments. We have demonstrated that the mutator phenotype ascribed to deficiency of the pmrA gene results in more biomass in the first 24 h but less during the post maturation stage (7-14 d) compared with BAA 894. The present study aimed to investigate the regulatory mechanism modulating biofilm formation due to pmrA mutation. The transcriptomic analyses of BAA 894 and s-3 were performed by RNA-sequencing on planktonic and biofilm cells collected at different time points. According to the results, when comparing biofilm to planktonic cells, expression of genes encoding outer membrane proteins, lysozyme, etc. were up-regulated, with LysR family transcriptional regulators, periplasmic proteins, etc. down-regulated. During biofilm formation, cellulose synthase operon genes, flagella-related genes, etc. played essential roles in different stages. Remarkably, pmrA varies the expression of a number of genes related to motility, biofilm formation, and antimicrobial resistance, including srfB, virK, mviM encoding virulence factor, flgF, fliN, etc. encoding flagellar assembly, and marA, ramA, etc. encoding AraC family transcriptional regulators in C. sakazakii. This study provides valuable insights into transcriptional regulation of C. sakazakii pmrA mutant during biofilm formation.
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Affiliation(s)
- Zhenbo Xu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China; Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38103, USA; Home Economics Technology, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand; National Institute of Fundamental Studies, Hantana Road, Kandy, Sri Lanka; Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center), Guangzhou, 510640, China
| | - Ziqi Liu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Thanapop Soteyome
- National Institute of Fundamental Studies, Hantana Road, Kandy, Sri Lanka
| | - Jingjing Hua
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China
| | - Liang Zhang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China.
| | - Lei Yuan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, China
| | - Yanrui Ye
- School of Biological Science and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Zhao Cai
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Janette M Harro
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD, 21201, USA
| | - Birthe Veno Kjellerup
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Junyan Liu
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Yanyan Li
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Xihu District, Hangzhou, 310024, Zhejiang Province, China.
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8
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Guan Y, Wang K, Zeng Y, Ye Y, Chen L, Huang T. Development of a Direct and Rapid Detection Method for Viable but Non-culturable State of Pediococcus acidilactici. Front Microbiol 2021; 12:687691. [PMID: 34276618 PMCID: PMC8283312 DOI: 10.3389/fmicb.2021.687691] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 05/31/2021] [Indexed: 02/05/2023] Open
Abstract
Pediococcus acidilactici may significantly reduce the pH-value, and thus has different influence, including serving as a probiotic in human microbiota but a spoilage in human food as it could change the flavor. Pediococcus acidilactici is also capable of entering into the viable but non-culturable (VBNC) state causing false negative results of standard culture-based detection method. Thus, development of detection method for VBNC state P. acidilactici is of great significance. In this study, propidium monoazide (PMA) combined with cross priming amplification (CPA) was developed to detect the VBNC cells of P. acidilactici and applied on the detection in different systems. With detection limit of 104 cells/ml, high sensitivity, and 100% specificity, PMA-CPA can successfully detect VBNC cells of P. acidilactici and be applied in with high robustness.
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Affiliation(s)
- Yu Guan
- Department of Urology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- *Correspondence: Yu Guan
| | - Kan Wang
- Center for Translational Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yang Zeng
- Shantou University Medical College, Shantou, China
| | - Yanrui Ye
- School of Biological Science and Engineering, South China University of Technology, Guangzhou, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Tengyi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
- Tengyi Huang
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9
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Ou A, Wang K, Ye Y, Chen L, Gong X, Qian L, Liu J. Direct Detection of Viable but Non-culturable (VBNC) Salmonella in Real Food System by a Rapid and Accurate PMA-CPA Technique. Front Microbiol 2021; 12:634555. [PMID: 33679667 PMCID: PMC7930388 DOI: 10.3389/fmicb.2021.634555] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 01/19/2021] [Indexed: 02/05/2023] Open
Abstract
Salmonella enterica is a typical foodborne pathogen with multiple toxic effects, including invasiveness, endotoxins, and enterotoxins. Viable but nonculturable (VBNC) is a type of dormant form preserving the vitality of microorganisms, but it cannot be cultured by traditional laboratory techniques. The aim of this study is to develop a propidium monoazide-crossing priming amplification (PMA-CPA) method that can successfully detect S. enterica rapidly with high sensitivity and can identify VBNC cells in food samples. Five primers (4s, 5a, 2a/1s, 2a, and 3a) were specially designed for recognizing the specific invA gene. The specificity of the CPA assay was tested by 20 different bacterial strains, including 2 standard S. enterica and 18 non-S. enterica bacteria strains covering Gram-negative and Gram-positive isolates. Except for the two standard S. enterica ATCC14028 and ATCC29629, all strains showed negative results. Moreover, PMA-CPA can detect the VBNC cells both in pure culture and three types of food samples with significant color change. In conclusion, the PMA-CPA assay was successfully applied on detecting S. enterica in VBNC state from food samples.
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Affiliation(s)
- Aifen Ou
- Department of Food, Guangzhou City Polytechnic, Guangzhou, China
| | - Kan Wang
- Center for Translational Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yanrui Ye
- School of Biological Science and Engineering, South China University of Technology, Guangzhou, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Xiangjun Gong
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, China
| | - Lu Qian
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, China
- Lu Qian,
| | - Junyan Liu
- Department of Civil and Environmental Engineering, University of Maryland, College Park, College Park, MD, United States
- *Correspondence: Junyan Liu,
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10
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Li Y, Huang TY, Mao Y, Chen Y, Shi F, Peng R, Chen J, Yuan L, Bai C, Chen L, Wang K, Liu J. Study on the Viable but Non-culturable (VBNC) State Formation of Staphylococcus aureus and Its Control in Food System. Front Microbiol 2020; 11:599739. [PMID: 33324380 PMCID: PMC7726111 DOI: 10.3389/fmicb.2020.599739] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 10/14/2020] [Indexed: 02/05/2023] Open
Abstract
A Viable but non-culturable (VBNC) state is a bacterial survival strategy under reverse conditions. It poses a significant challenge for public health and food safety. In this study, the effect of external environmental conditions including acid, nutrition, and salt concentrations on the formation of S. aureus VBNC states at low temperatures were investigated. Different acidity and nutritional conditions were then applied to food products to control the VBNC state formation. Four different concentration levels of each factor (acid, nutrition, and salt) were selected in a total of 16 experimental groups. Nutrition showed the highest influence on the VBNC state formation S. aureus, followed by acid and salt. The addition of 1% acetic acid could directly kill S. aureus cells and inhibit the formation of the VBNC state with a nutrition concentration of 25, 50, and 100%. A propidium monoazide-polymerase chain reaction (PMA-PCR) assay was applied and considered as a rapid and sensitive method to detect S. aureus in VBNC state with the detection limit of 104 CFU/mL.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Teng-Yi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yuzhu Mao
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Yanni Chen
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Fan Shi
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Ruixin Peng
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Jinxuan Chen
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
| | - Lei Yuan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, China
| | - Caiying Bai
- Guangdong Women and Children Hospital, Guangzhou, China
| | - Ling Chen
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Research Institute for Food Nutrition and Human Health, Guangzhou, China
| | - Kan Wang
- Research Center for Translational Medicine, The Second Affiliated Hospital, Medical College of Shantou University, Shantou, China
| | - Junyan Liu
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, United States
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11
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Veronica EK, Sara A O, Everardo CQ, Héctor Q, Oscar MC, Elizabeth FR, Irma RP, José AG, Bulmaro C, Rigoberto HC, Juan XC, Ariadnna CC. Proteomics profiles of Cronobacter sakazakii and a fliF mutant: Adherence and invasion in mouse neuroblastoma cells. Microb Pathog 2020; 149:104595. [PMID: 33157215 DOI: 10.1016/j.micpath.2020.104595] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 01/17/2023]
Abstract
Cronobacter sakazakii is an opportunistic foodborne pathogen associated with necrotizing enterocolitis, bacteremia, and meningitis in infants. A comparative proteomic study of C. sakazakii ATCC BAA-894 (CS WT) and a fliF::Tn5 mutant was performed, including the ability of both strains to adhere to and invade N1E-115 cells. To achieve this goal, a nonmotile C. sakazakii ATCC BAA-894 fliF::Tn5 (CS fliF::Tn5) strain was generated using an EZ-Tn5 <KAN-2>Tnp Transposome kit. Analysis of differential protein expression showed that 81.49% (361/443) of the proteins were expressed in both strains, 8.35% (37/443) were exclusively expressed in the CS WT strain, and 10.16% (45/443) were exclusively expressed in the CS fliF::Tn5 strain. The main exclusively expressed proteins in the CS WT strain were classified into the "cell motility" and "signal transduction mechanisms" subcategories. The proteins exclusively expressed in the CS fliF::Tn5 strain were classified into the following subcategories: "intracellular trafficking, secretion, and vesicular transport", "replication, recombination, and repair", "nucleotide transport and metabolism", "carbohydrate transport and metabolism", "coenzyme transport and metabolism", and "lipid transport and metabolism". Expression of the Cpa protein was detected in both strains, but Cpa was more abundant in the CS WT strain than in the CS fliF::Tn5 strain. A significant increase (p = 0.0001) in adherence to N1E-115 cells was observed in the nonmotile CS fliF::Tn5 strain (31.3 × 106 CFU/mL) compared to the CS WT strain (14.5 × 106 CFU/mL). Additionally, the CS WT strain showed a 0.17% invasion frequency in N1E-115 cells, which was significantly higher (p = 0.01) than that of the nonmotile CS fliF::Tn5 strain. In conclusion, the proteins involved in the motility were mainly identified by proteomic analysis in the CS WT strain compared to the CS fliF::Tn5 strain. Our data indicate that flagella are required to promote the invasion of N1E-115 cells and that the absence of flagella significantly increases the adherence to N1E-115 cells.
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Affiliation(s)
- Esteban-Kenel Veronica
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Ciudad de México, Mexico; Laboratorio de Ingeniería Genética, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Ochoa Sara A
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Ciudad de México, Mexico
| | - Curiel-Quesada Everardo
- Laboratorio de Ingeniería Genética, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Quezada Héctor
- Unidad de Investigación Epidemiológica en Endocrinología y Nutrición. Hospital Infantil de México Federico Gómez, Ciudad de México, Mexico
| | - Medina-Contreras Oscar
- Unidad de Investigación Epidemiológica en Endocrinología y Nutrición. Hospital Infantil de México Federico Gómez, Ciudad de México, Mexico
| | - Fernández-Rendón Elizabeth
- Laboratorio de Microbiología Sanitaria, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Rosas-Pérez Irma
- Laboratorio de Aerobiología, Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Arellano-Galindo José
- Área de Virología, Laboratorio de Infectología, Hospital Infantil de México Federico Gómez, Ciudad de México, Mexico
| | - Cisneros Bulmaro
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Hernandez-Castro Rigoberto
- Departamento de Ecología de Agentes Patógenos. Hospital General "Dr. Manuel Gea González", Delegación Tlalpan, México D., 14080, Mexico
| | - Xicohtencatl-Cortes Juan
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Ciudad de México, Mexico.
| | - Cruz-Córdova Ariadnna
- Laboratorio de Investigación en Bacteriología Intestinal, Hospital Infantil de México Federico Gómez, Ciudad de México, Mexico.
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12
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Chen DQ, Huang T, Wang Q, Bai C, Yang L. Analysis on the virulomes and resistomes of multi-drug resistance clinical Escherichia coli isolates, as well as the interactome with gut microbiome. Microb Pathog 2020; 148:104423. [PMID: 32768515 DOI: 10.1016/j.micpath.2020.104423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 07/07/2020] [Accepted: 07/21/2020] [Indexed: 02/05/2023]
Abstract
Escherichia coli is one of the most diverse microbial species. Pathogenic E. coli is capable of causing various diseases in humans, including several types of diarrhea, urinary tract infections, sepsis, and meningitis. This study focused on the antibiotic susceptibility profile and genomic analysis of a clinical E. coli Guangzhou-Eco330 isolated from a hospitalized 8-year-old female patient suffered from pulmonary infection in 2017. Susceptibility to 15 antibiotics were determined using Vitek2™ Automated Susceptibility System and Etest strips and interpreted based on CLSI guidelines. The genome was sequenced using Illumina Hiseq 2500 platform and assembled de novo using Velvet, followed by bioinformatics analysis. The genome has a length of 5,132,642 bp and contains 4989 predicted genes with an average GC content of 50.51%. The carriage of rfbE gene suggested the strain belonging to O157. In the genome, 70 non-coding RNAs, 50 repeat sequences, 18 transposons, 78 GIs, 9 CRISPRs, and 3 large prophages were identified. 37 PHI related genes and 108 virulence genes were determined to contribute to its pathogenicity. Specifically, the acquisition of multiple antibiotic resistance genes including blaCTX-M-55, blaOXA-10, blaCMY-48, tetB, and qnrS1 contributed to its resistance to penicillins, telracyclines, cephalosporin, and quinolones. The understanding of the genome may aid in further study on the clinical control of multi-drug resistance E. coli.
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Affiliation(s)
- Ding-Qiang Chen
- Department of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China.
| | - Tengyi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China.
| | - Qun Wang
- Department of Laboratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
| | - Caiying Bai
- Guangdong Women and Children Hospital, Guangzhou, 510010, China.
| | - Ling Yang
- Department of Laboratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
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13
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Fu J, Wang K, Ye C, Chen L, Liang Y, Mao Y, Chen J, Peng R, Chen Y, Shi F, Huang TY, Liu J. Study on the virulome and resistome of a vancomycin intermediate-resistance Staphylococcus aureus. Microb Pathog 2020; 145:104187. [PMID: 32275941 DOI: 10.1016/j.micpath.2020.104187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/03/2020] [Accepted: 04/03/2020] [Indexed: 02/05/2023]
Abstract
Methicillin-resistant S. aureus (MRSA) has been considered a potential "Super Bugs", responsible for various infectious diseases. Vancomycin has been the most effective antibitic to treat MRSA originated infections. In this study, we aimed at investigating the genomic features of a vancomycin intermediate-resistance S. aureus strain Guangzhou-SauVS2 isolated from a female patient suffering from chronic renal function failure, emphasizing on its antimicrobial resistance and virulence determinants. The genome has a total length of 2,605,384 bp and the G+C content of 33.21%, with 2,239 predicted genes annotated with GO terms, COG categories, and KEGG pathways. Besides the carriage of vancomycin b-type resistance protein responsible for the vancomycin intermediate-resistance, S. aureus strain Guangzhou-SauVS2 showed resistance to β-lactams, quinolones, macrolide, and tetracycline, due to the acquisition of corresponding antimicrobial resistance genes. In addition, virulence factors including adherence, antiphagocytosis, iron uptake, and toxin were determined, indicating the pathogenesis of the strain.
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Affiliation(s)
- Jie Fu
- Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China
| | - Kan Wang
- Research Center for Translational Medicine, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Congxiu Ye
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510640, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Yi Liang
- Guangdong Zhongqing Font Biochemical Science and Technology Co. Ltd., Maoming, Guangdong, 525427, China
| | - Yuzhu Mao
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Jinxuan Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Ruixin Peng
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Yanni Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Fan Shi
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Teng-Yi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, North Dongxia Road, Shantou, 515041, Shantou, Guangdong, China.
| | - Junyan Liu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China.
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14
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Chen W, Chen H, Fu S, Lin X, Zheng Z, Zhang J. Microbiome characterization and re-design by biologic agents for inflammatory bowel disease insights. Bioprocess Biosyst Eng 2020; 44:929-939. [PMID: 32458051 DOI: 10.1007/s00449-020-02380-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 05/12/2020] [Indexed: 12/14/2022]
Abstract
The therapeutic effect of inflammatory bowel disease has improved in the past decades, but most of patients cannot tolerate, do not respond to drugs, or relapse after treating with conventional therapy. Therefore, new and more effective treatment methods are still needed in treatment of IBD. In this review, we will discuss the relevant mechanisms and the latest research progress of biologics (anti-TNF treatments, interleukin inhibitors, integrin inhibitors, antisense oligonucleotide, and JAK inhibitors) for IBD, focus on the efficacy and safety of drugs for moderate-to-severe IBD, and summarize the clinical status and future development direction of biologics in IBD.
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Affiliation(s)
- Wenshuo Chen
- Department of Gastrointestinal Surgery, Zhujiang Hospital, Southern Medical University, GuangZhou, 510280, China
| | - Haijin Chen
- Department of Gastrointestinal Surgery, Zhujiang Hospital, Southern Medical University, GuangZhou, 510280, China.
| | - Shudan Fu
- Ophthalmology Department, Zhujiang Hospital, Southern Medical University, GuangZhou, 510280, China
| | - Xiaohua Lin
- Department of Gastrointestinal Surgery, Zhujiang Hospital, Southern Medical University, GuangZhou, 510280, China
| | - Zheng Zheng
- Department of Gastrointestinal Surgery, Zhujiang Hospital, Southern Medical University, GuangZhou, 510280, China
| | - Jinlong Zhang
- Department of Gastrointestinal Surgery, Zhujiang Hospital, Southern Medical University, GuangZhou, 510280, China
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15
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Li Y, Qiu Y, Ye C, Chen L, Liang Y, Liu G, Liu J. High-flux simultaneous screening of common foodborne pathogens and their virulent factors. Bioprocess Biosyst Eng 2020; 43:693-700. [PMID: 31863186 DOI: 10.1007/s00449-019-02267-7] [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: 08/28/2019] [Accepted: 10/30/2019] [Indexed: 02/05/2023]
Abstract
Rapid and sensitive detection techniques for foodborne pathogens are important to the food industry. However, traditional detection methods rely on bacterial culture in combination with biochemical tests, a process that typically takes 4-7 days to complete. In this study, we described a high-flux polymerase chain reaction (PCR) method for simultaneous detection of nine targeted genes (rfbE, stx1, stx2, invA, oprI, tlh, trh, tdh, and hlyA) with multiplex strains. The designed primers were highly specific for their respective target gene fragments. As the selected primers follow the principles of similar melting and annealing temperature, all the targeted genes could be detected for one strain with the same PCR program. Combining with 96-well PCR plate, by adding a single different gene to each well in each row, both the ATCC strains (E. coli, Salmonella spp., V. parahaemolyticus, L. monocytogenes, P. aeruginosa, S. aureus) and the clinical strains (E. coli, P. aeruginosa, S. aureus) were simultaneously detected to carry their specific and virulence genes. Therefore, using 96-well PCR plate for PCR amplification might be applied to high-flux sequencing of specific and virulence genes.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China
| | - Yisen Qiu
- Department of Spine Surgery, The Second Affiliated Hospital of Shantou University Medical College, North Dongxia Road, Shantou, 515041, Guangdong, China
| | - Congxiu Ye
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510640, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Yi Liang
- Guangdong Zhongqing Font Biochemical Science and Technology Co. Ltd, Maoming, 525427, Guangdong, China
| | - Guoxing Liu
- Guangzhou KEO Biotechnology Co. LTD, Guangzhou, Guangdong, China.
| | - Junyan Liu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China.
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16
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Zheng Y, Yu J, Liang C, Li S, Wen X, Li Y. Characterization on gut microbiome of PCOS rats and its further design by shifts in high-fat diet and dihydrotestosterone induction in PCOS rats. Bioprocess Biosyst Eng 2020; 44:953-964. [PMID: 32157446 DOI: 10.1007/s00449-020-02320-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 02/26/2020] [Indexed: 12/11/2022]
Abstract
Polycystic ovary syndrome (PCOS) is associated with gut microbiota disturbance. Emerging evidence has shown that gut microbiota plays a major role in the development of PCOS. To better understand how the gut microbiota contributes to the development of PCOS, we investigated the influences of high-fat diet and hyperandrogenism, independently or synergistically, have on the gut microbiota in rats. Furthermore, we explored the associations between gut microbiota and hyperandrogenism or other hallmarks of PCOS. Twenty female SD rats were randomized at aged 3 weeks into 4 groups (n = 5, each); HA: PCOS rats fed with ordinary diet; HF: rats with high-fat diet (HFD); HA-HF: PCOS rats fed with HFD; and C: control rats with ordinary diet. PCOS rat model was induced by 5α-dihydrotestosterone (DHT) injection for 6 weeks. The fasting blood glucose (FBG), plasma insulin, testosterone, free testosterone, TNF-α, MDA, SOD, LPS, TLR4, TG, TC, HDL-C, and LDL-C levels were measured. The molecular ecology of the fecal gut microbiota was analyzed by 16S rDNA high-throughput sequencing. The results showed that rats in the HA and HA-HF group displayed abnormal estrous cycles with increasing androgen level and exhibited multiple large cysts with diminished granulosa layers in ovarian tissues. Compare with the C group, relative abundance of the Bacteroidetes phylum decreased significantly in the other groups (P < 0.05). The Chao1 was the highest in the group C and significantly higher than the HA-HF group (P < 0.05). T, FT, insulin, MDA, LPS, and TNF-α levels had the negative correlation with the richness of community (Chao1 index) in the gut. The rats in the HF and HA-HF groups tended to have lower Shannon and Simpson indices than the C group (P < 0.01, respectively). However, there were no significant differences between C group and the HA group in the Shannon and Simpson values. Beta diversity analysis was then performed based on a weighted UniFrac analysis. The PCoA plots showed a clear separation of the C group from the other groups. ANOSIM analysis of variance confirmed that there were statistically significant separations between the C group and the HA, HA-HF, and HF groups (P < 0.01, respectively). These results showed that DHT with HFD could lower diversity of the gut microbial community. Both HFD and DHT could shift the overall gut microbial composition and change the composition of the microbial community in gut. Furthermore, our analyses demonstrated that the levels of TG, MDA, TNF-α, LPS, TLR4, T, FT, FINS, and HDL-C were correlated with the changes of in the gut microbiome. HFD and DHT were associated with the development and pathology of PCOS by shaping gut microbial communities.
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Affiliation(s)
- Yanhua Zheng
- Department of Traditional Chinese Medicine, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Jingwei Yu
- Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Chengjie Liang
- Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Shuna Li
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Xiaohui Wen
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yanmei Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China.
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17
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Wang M, Wang L, Wu P, Chen T, Zhu Y, Zhang Y, Wei Y, Qian C, Wang Y, Liu B. Genomics and Experimental Analysis Reveal a Novel Factor Contributing to the Virulence of Cronobacter sakazakii Strains Associated With Neonate Infection. J Infect Dis 2020; 220:306-315. [PMID: 30835279 DOI: 10.1093/infdis/jiz098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/02/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Cronobacter sakazakii causes meningitis and necrotizing enterocolitis in premature infants. However, its virulence determinants, especially those specific for strains associated with neonate infections, remain largely unknown. METHODS In this study, we performed a comparative genomic analysis of 209 C. sakazakii genomes, and 8 clonal groups (CGs) were revealed. RESULTS CG1 and CG2 were found to be significantly associated with neonate infections, and significantly prevalent genes in these 2 CGs were identified. Of these, a gene encoding the LysR-type regulator, CklR, was shown to contribute to bacterial pathogenicity based on animal experiments. We found that CklR directly binds and activates the suf Fe-S cluster biosynthesis operon, and high expression of the suf operon increases bacterial resistance to oxidative stress, which increases survival within the host. This leads to a high degree of bacteremia, which contributes to the development of meningitis. CONCLUSIONS Our work revealed a novel virulence factor specific to predominant pathogenic C. sakazakii strains.
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Affiliation(s)
- Min Wang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China.,Center for Microbial Functional Genomics and Detection Technology, Ministry of Education, Tianjin, People's Republic of China.,Tianjin Key Laboratory of Microbial Functional Genomics, People's Republic of China
| | - Lu Wang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Pan Wu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Tingting Chen
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Yiming Zhu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Yang Zhang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Yi Wei
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Chengqian Qian
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Yuhui Wang
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China
| | - Bin Liu
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, People's Republic of China.,TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin, People's Republic of China.,Center for Microbial Functional Genomics and Detection Technology, Ministry of Education, Tianjin, People's Republic of China.,Tianjin Key Laboratory of Microbial Functional Genomics, People's Republic of China
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18
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Li Y, Huang TY, Ye C, Chen L, Liang Y, Wang K, Liu J. Formation and Control of the Viable but Non-culturable State of Foodborne Pathogen Escherichia coli O157:H7. Front Microbiol 2020; 11:1202. [PMID: 32612584 PMCID: PMC7308729 DOI: 10.3389/fmicb.2020.01202] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/12/2020] [Indexed: 02/05/2023] Open
Abstract
As a common foodborne pathogen, Escherichia coli O157:H7 produces toxins causing serious diseases. However, traditional methods failed in detecting E. coli O157:H7 cells in the viable but non-culturable (VBNC) state, which poses a threat to food safety. This study aimed at investigating the formation, control, and detection of the VBNC state of E. coli O157:H7. Three factors including medium, salt, and acid concentrations were selected as a single variation. Orthogonal experiments were designed with three factors and four levels, and 16 experimental schemes were used. The formation of the VBNC state was examined by agar plate counting and LIVE/DEAD® BacLightTM bacterial viability kit with fluorescence microscopy. According to the effects of environmental conditions on the formation of the VBNC state of E. coli O157:H7, the inhibition on VBNC state formation was investigated. In addition, E. coli in the VBNC state in food samples (crystal cake) was detected by propidium monoazide-polymerase chain reaction (PMA-PCR) assays. Acetic acid concentration showed the most impact on VBNC formation of E. coli O157:H7, followed by medium and salt concentration. The addition of 1.0% acetic acid could directly kill E. coli O157:H7 and eliminate its VBNC formation. In crystal cake, 25, 50, or 100% medium with 1.0% acetic acid could inhibit VBNC state formation and kill E. coli O157:H7 within 3 days. The VBNC cell number was reduced by adding 1.0% acetic acid. PMA-PCR assay could be used to detect E. coli VBNC cells in crystal cake with detection limit at 104 CFU/ml. The understanding on the inducing and inhibitory conditions for the VBNC state of E. coli O157:H7 in a typical food system, as well as the development of an efficient VBNC cell detection method might aid in the control of VBNC E. coli O157:H7 cells in the food industry.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Teng-Yi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Congxiu Ye
- Department of Dermato-Venereology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Yi Liang
- Guangdong Zhongqing Font Biochemical Science and Technology Co. Ltd., Maoming, China
| | - Kan Wang
- Research Center for Translational Medicine, The Second Affiliated Hospital, Medical College of Shantou University, Shantou, China
- *Correspondence: Junyan Liu,
| | - Junyan Liu
- Department of Civil and Environmental Engineering, A. James Clark School of Engineering, University of Maryland, College Park, MD, United States
- Kan Wang,
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19
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Zhou W, Wang K, Hong W, Bai C, Chen L, Fu X, Huang T, Liu J. Development and Application of a Simple "Easy To Operate" Propidium Monoazide-Crossing Priming Amplification on Detection of Viable and Viable But Non-culturable Cells of O157 Escherichia coli. Front Microbiol 2020; 11:569105. [PMID: 33101241 PMCID: PMC7546352 DOI: 10.3389/fmicb.2020.569105] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/24/2020] [Indexed: 02/05/2023] Open
Abstract
O157 Escherichia coli is one of the most important foodborne pathogens causing disease even at low cellular numbers. Thus, the early and accurate detection of this pathogen is important. However, due to the formation of viable but non-culturable (VBNC) status, the golden standard culturing methodology fails to identify O157 E. coli once it enters VBNC status. Crossing priming amplification (CPA) is a novel, simple, easy-to-operate detection technology that amplifies DNA with high speed, efficiency, and specificity under isothermal conditions. The objective of this study was to firstly develop and apply a CPA assay with propidium monoazide (PMA) for the rapid detection of the foodborne E. coli O157:H7 in VBNC state. Five primers (2a/1s, 2a, 3a, 4s, and 5a) were specially designed for recognizing three targets, which were rfbE, stx1, and stx2, and evaluated for its effectiveness in detecting VBNC cell of E. coli O157:H7 with detection limits of pure VBNC culture at 103, 105, and 105 colony-forming units (CFUs)/ml for rfbE, stx1, and stx2, respectively, whereas those of food samples (frozen pastry and steamed bread) were 103, 105, and 105 CFUs/ml. The application of the PMA-CPA assay was successfully used on detecting E. coli O157:H7 in VBNC state from food samples. In conclusion, this is the first development of PMA-CPA assay on the detection of VBNC cell, which was found to be useful and a powerful tool for the rapid detection of E. coli O157:H7 in VBNC state. Undoubtedly, the PMA-CPA method can be of high value to the food industry owing to its various advantages such as speed, specificity, sensitivity, and cost-effectiveness.
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Affiliation(s)
- Wenqu Zhou
- GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, China
| | - Kan Wang
- Research Center for Translational Medicine, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Wei Hong
- GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, China
| | - Caiying Bai
- Guangdong Women and Children Hospital, Guangzhou, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
- Research Institute for Food Nutrition and Human Health, Guangzhou, China
| | - Xin Fu
- GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou, China
- *Correspondence: Xin Fu,
| | - Tengyi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Junyan Liu
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, United States
- Junyan Liu,
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20
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Li Y, Huang TY, Mao Y, Chen Y, Shi F, Peng R, Chen J, Bai C, Chen L, Wang K, Liu J. Effect of Environmental Conditions on the Formation of the Viable but Nonculturable State of Pediococcus acidilactici BM-PA17927 and Its Control and Detection in Food System. Front Microbiol 2020; 11:586777. [PMID: 33117324 PMCID: PMC7550757 DOI: 10.3389/fmicb.2020.586777] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 08/25/2020] [Indexed: 02/05/2023] Open
Abstract
Objective: This study aimed to investigate the effect of environmental conditions including nutrient content, acetic acid concentration, salt concentration, and temperature on the formation of viable but nonculturable (VBNC) state of Pediococcus acidilactici, as well as its control and detection in food system. Methods: Representing various environmental conditions in different food systems, 16 induction groups were designed for the formation of VBNC state of P. acidilactici. Traditional plate counting was applied to measure the culturable cell numbers, and Live/Dead Bacterial Viability Kit combined with fluorescent microscopy was used to identify viable cells numbers. The inhibition of bacterial growth and VBNC state formation by adjusting the environmental conditions were investigated, and the clearance effect of VBNC cells in crystal cake system was studied. In addition, a propidium monoazide-polymerase chain reaction (PMA-PCR) assay was applied to detect the VBNC P. acidilactici cells in crystal cake food system. Results: Among the environmental conditions included in this study, acetic acid concentration had the greatest effect on the formation of VBNC state of P. acidilactici, followed by nutritional conditions and salt concentration. Reducing nutrients in the environment and treating with 1.0% acetic acid can inhibit P. acidilactici from entering the VBNC state. In the crystal cake system, the growth of P. acidilactici and the formation of VBNC state can be inhibited by adding 1.0% acetic acid and storing at -20°C. In crystal cake system, the PMA-PCR assay can be used to detect VBNC P. acidilactici cells at a concentration higher than 104 cells/ml. Conclusion: The VBNC state of P. acidilactici can be influenced by the changing of environmental conditions, and PMA-PCR assay can be applied in food system for the detection of VBNC P. acidilactici cells.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Teng-Yi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Yuzhu Mao
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Yanni Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Fan Shi
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Ruixin Peng
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Jinxuan Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
| | - Caiying Bai
- Guangdong Women and Children Hospital, Guangzhou, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, China
- Research Institute for Food Nutrition and Human Health, Guangzhou, China
| | - Kan Wang
- Research Center for Translational Medicine, The Second Affiliated Hospital, Medical College of Shantou University, Shantou, China
- Kan Wang,
| | - Junyan Liu
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, United States
- *Correspondence: Junyan Liu,
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Li Y, Huang T, Bai C, Fu J, Chen L, Liang Y, Wang K, Liu J, Gong X, Liu J. Reduction, Prevention, and Control of Salmonella enterica Viable but Non-culturable Cells in Flour Food. Front Microbiol 2020; 11:1859. [PMID: 32973696 PMCID: PMC7472744 DOI: 10.3389/fmicb.2020.01859] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/15/2020] [Indexed: 02/05/2023] Open
Abstract
The processing and storage conditions of flour food inevitably pose environmental stress, which promote bacteria to enter a viable but non-culturable (VBNC) state. The existence of VBNC cells causes false-negative detection in traditional culture-based detection methods, resulting in food quality and safety issues. This study aimed at investigating the influence factors including nutrition, acid, salt, and temperature for the entry into a VBNC state of Salmonella enterica and an efficient detection method. During induction with multi-stress conditions, nutrition starvation antagonizes with low-level acidity. Besides, high-level acidity was considered as an inhibitor for VBNC induction. Four inducers including nutrition starvation, salt stress, low-level acidity, and low temperature were concluded for a VBNC state. In addition, the keynote conditions for S. enterica entering a VBNC state included (i) nutrient-rich acidic environment, (ii) oligotrophic low-acidity environment, and (iii) oligotrophic refrigerated environment. Based on the keynote conditions, the environmental conditions of high acidity (1.0% v/v acetate) with low temperature (-20°C) could successfully eliminate the formation of S. enterica VBNC cells in flour food. In addition, combining with propidium monoazide pretreatment, PCR technology was applied to detect S. enterica VBNC cells. The sensitivity of the PMA-PCR technology was 105 CFU/ml in an artificially simulated food system. The results derived from this study might aid in the detection and control of VBNC state S. enterica in flour food products.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Tengyi Huang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Caiying Bai
- Guangdong Women and Children Hospital, Guangzhou, China
| | - Jie Fu
- Department of Haematology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Ling Chen
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center), Guangzhou, China
| | - Yi Liang
- Guangdong Zhongqing Font Biochemical Science and Technology Co., Ltd., Maoming, China
| | - Kan Wang
- Research Center of Translational Medicine, The Second Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Jun Liu
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, China
| | - Xiangjun Gong
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, China
- *Correspondence: Xiangjun Gong,
| | - Junyan Liu
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, United States
- Junyan Liu,
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Zhou A, Cao Y, Zhou D, Hu S, Tan W, Xiao X, Yu Y, Li X. Global transcriptomic analysis of Cronobacter sakazakii CICC 21544 by RNA-seq under inorganic acid and organic acid stresses. Food Res Int 2019; 130:108963. [PMID: 32156398 DOI: 10.1016/j.foodres.2019.108963] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/23/2019] [Accepted: 12/25/2019] [Indexed: 01/07/2023]
Abstract
Cronobacter sakazakii is a common foodborne pathogen that can tolerate various stress conditions. Acidic environment is a common stress condition encountered by bacteria in food processing and gastrointestinal digestion, including both inorganic and organic acids. In order to elucidate the Acid Tolerance Response (ATR) of C. sakazakii, we performed high-throughput RNA-seq to compare gene expression under hydrochloric acid and citric acid stresses. In this study, 107 differentially expressed genes (DEGs) were identified in both acids, of which 85 DEGs were functionally related to the regulation of acid tolerance. Multiple layers of mechanisms may be applied by C. sakazakii in response to acid stress: Firstly, in order to reduce excessive intracellular protons, C. sakazakii pumps them out through trans-membrane proteins or consumes them through metabolic reactions. Secondly, under acidic conditions, a large amount of reactive oxygen species and hydroxyl radicals accumulate in the cells, resulting in oxidative damage. C. sakazakii protects cells by up-regulating the antioxidant stress genes such as soxS and madB. Thirdly, C. sakazakii chooses energy efficient metabolic pathways to reduce energy consumption and maintain necessary processes. Finally, genes involved in chemotaxis and motility were differentially expressed to respond to different acidic conditions. This study systematically analyzed the acid-resistant mechanism of C. sakazakii under the stress of organic and inorganic acids, and provided a theoretical basis for better control of its contamination in food.
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Affiliation(s)
- Ailian Zhou
- School of Food Sciences and Engineering, South China University of Technology, Guangzhou City, Guangdong Province 510640, China
| | - Yifang Cao
- School of Food Sciences and Engineering, South China University of Technology, Guangzhou City, Guangdong Province 510640, China
| | - Donggen Zhou
- Ningbo International Travel Healthcare Center. No. 336 Liuting Street, Haishu District, Ningbo City, Zhejiang Province 315012, China
| | - Shuangfang Hu
- Key Laboratory of Molecular Epidemiology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen City, Guangdong Province 518055, China
| | - Wanjing Tan
- School of Food Sciences and Engineering, South China University of Technology, Guangzhou City, Guangdong Province 510640, China
| | - Xinglong Xiao
- School of Food Sciences and Engineering, South China University of Technology, Guangzhou City, Guangdong Province 510640, China.
| | - Yigang Yu
- School of Food Sciences and Engineering, South China University of Technology, Guangzhou City, Guangdong Province 510640, China
| | - Xiaofeng Li
- State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Sciences, South China University of Technology, 381 Wusan Road, Tianhe District, Guangzhou City 510640, Guangdong Province, China.
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Aly MA, Domig KJ, Kneifel W, Reimhult E. Whole Genome Sequencing-Based Comparison of Food Isolates of Cronobacter sakazakii. Front Microbiol 2019; 10:1464. [PMID: 31333604 PMCID: PMC6615433 DOI: 10.3389/fmicb.2019.01464] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/11/2019] [Indexed: 12/13/2022] Open
Abstract
Cronobacter sakazakii is an emerging foodborne pathogen, which is linked to life-threatening infections causing septicemia, meningitis, and necrotizing enterocolitis. These infections have been epidemiologically connected to ingestion of contaminated reconstituted powder infant formula. Even at low water activity C. sakazakii can survive for a long time; it is capable of protective biofilm formation and occasionally shows high virulence and pathogenicity even following stressful environmental conditions. Hence it is a challenging task for the food industry to control contamination of food ingredients and products through the entire production chain, since an increasing number of severe food-related outbreaks of C. sakazakii infections has been observed. The seemingly great capability of C. sakazakii to survive even strict countermeasures combined with its prevalence in many food ingredients requires a greater in depth understanding of its virulence factors to master the food safety issues related to this organism. In this context, we present the whole genome sequence (WGS) of two different C. sakazakii isolated from skimmed milk powder (C7) and ready-to-eat salad mix (C8), respectively. These are compared to other, already sequenced, C. sakazakii genomes. Sequencing of the fusA allele revealed that both isolates were C. sakazakii. We investigated the molecular characteristics of both isolates relevant for genes associated with pathogenesis and virulence factors, resistance to stressful environmental conditions (e.g., osmotic and heat), survival in desiccation as well as conducted a comparative genomic analysis. By using multi-locus sequence typing (MLST), the genetic type of both isolates is assessed and the number of unique genes is determined. DNA of C. sakazakii C8 is shown to hold a novel and unique sequence type; the number of unique genes identified in the genomic sequence of C. sakazakii C7 and C8 were 109 and 188, respectively. Some of the determined unique genes such as the rhs and VgrG genes are linked to the Type VI Secretion System cluster, which is associated with pathogenicity and virulence factors. Moreover, seven genes encoding for multi-drug resistance were found in both isolates. The finding of a number of genes linked to producing capsules and biofilm are likely related to the observed resistance to desiccation.
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Affiliation(s)
- Mohamed A Aly
- Department of Nanobiotechnology, Institute for Biologically Inspired Materials, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.,Department of Food Science, Faculty of Agriculture, Ain Shams University, Cairo, Egypt
| | - Konrad J Domig
- Department of Food Science and Technology, Institute of Food Science, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Wolfgang Kneifel
- Department of Food Science and Technology, Institute of Food Science, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Erik Reimhult
- Department of Nanobiotechnology, Institute for Biologically Inspired Materials, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
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Cui X, Ren L, Shan Y, Wang X, Yang Z, Li C, Xu J, Ma B. Smartphone-based rapid quantification of viable bacteria by single-cell microdroplet turbidity imaging. Analyst 2019; 143:3309-3316. [PMID: 29774899 DOI: 10.1039/c8an00456k] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Standard plate count (SPC) has been recognized as the golden standard for the quantification of viable bacteria. However, SPC usually takes one to several days to grow individual cells into a visible colony, which greatly hampers its application in rapid bacteria enumeration. Here we present a microdroplet turbidity imaging based digital standard plate count (dSPC) method to overcome this hurdle. Instead of cultivating on agar plates, bacteria are encapsulated in monodisperse microdroplets for single-cell cultivation. Proliferation of the encapsulated bacterial cell produced a detectable change in microdroplet turbidity, which allowed, after just a few bacterial doubling cycles (i.e., a few hours), enumeration of viable bacteria by visible-light imaging. Furthermore, a dSPC platform integrating a power-free droplet generator with smartphone-based turbidity imaging was established. As proof-of-concept demonstrations, a series of Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Bacillus subtilis) samples were quantified via the smartphone dSPC accurately within 6 hours, representing a detection sensitivity of 100 CFU ml-1 and at least 3 times faster. In addition, Enterobacter sakazakii (E. sakazakii) in infant milk powder as a real sample was enumerated within 6 hours, in contrast to the 24 hours needed in traditional SPC. Results with high accuracy and reproducibility were achieved, with no difference in counts found between dSPC and SPC. By enabling label-free, rapid, portable and low-cost enumeration and cultivation of viable bacteria onsite, smartphone dSPC forms the basis for a temporally and geographically trackable network for surveying live microbes globally where every citizen with a cellphone can contribute anytime and anywhere.
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Affiliation(s)
- Xiaonan Cui
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China.
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25
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Chen Y, Su JQ, Zhang J, Li P, Chen H, Zhang B, Gin KYH, He Y. High-throughput profiling of antibiotic resistance gene dynamic in a drinking water river-reservoir system. WATER RESEARCH 2019; 149:179-189. [PMID: 30447523 DOI: 10.1016/j.watres.2018.11.007] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/25/2018] [Accepted: 11/03/2018] [Indexed: 06/09/2023]
Abstract
The rapid construction of reservoir in river basin generates a river-reservoir system containing an environmental gradient from river system to reservoir system in modern aquatic environment worldwide. Profiles of antibiotic resistance genes (ARGs) in river-reservoir system is essential to better understand their dynamic mechanisms in aquatic eco-environment. In this study, we investigated the diversity, abundance, distribution of ARGs and mobile genetic elements (MGEs) in a representative river-reservoir system using high-throughput quantitative PCR, as well as ranked the factors (e.g. antibiotics, bacterial biomass, bacteria communities, and MGEs) influencing the patterns of ARGs based on structural equation models (SEMs). Seasonal variations in absolute abundance of ARGs and MGEs exhibited similar trends with local rainfall, suggesting that seasonal runoff induced by the rainfall potentially promote the absolute abundance of ARGs and MGEs. In contrast, environmental gradient played more important roles in the detected number, relative abundance, distribution pattern of ARGs and MGEs in the river-reservoir system. Moreover, environmental gradient also made the co-occurrence patterns associated with ARGs subtypes, MGEs and bacteria genera in river system different from those in reservoir system. The SEMs revealed that MGEs contributed the most to shape the ARG profiles. Overall, our findings provide novel insights into the mechanisms of environmental gradient on ARGs dynamics in river-reservoir system, probably via influencing the MGEs, antibiotics, pathogenic bacteria community and nonpathogenic bacteria community.
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Affiliation(s)
- Yihan Chen
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China; School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, Anhui Province, 230601, China
| | - Jian-Qiang Su
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Junya Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Peng Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Hongjie Chen
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore, 117411, Singapore; Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, E1A 07-03, Singapore, 117576, Singapore
| | - Bo Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Karina Yew-Hoong Gin
- NUS Environmental Research Institute, National University of Singapore, 5A Engineering Drive 1, #02-01, Singapore, 117411, Singapore; Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, E1A 07-03, Singapore, 117576, Singapore
| | - Yiliang He
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China; China-UK Low Carbon College, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
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High flux isothermal assays on the pathogenic features of Mycoplasma pneumoniae. Microb Pathog 2018; 120:219-222. [PMID: 29730516 DOI: 10.1016/j.micpath.2018.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 04/10/2018] [Accepted: 05/02/2018] [Indexed: 11/20/2022]
Abstract
As one of the most important pathogens, M. pneumoniae is a causative agent responsible for atypical and other respiratory tract infections, even its extra-pulmonary complications. This study aims to use the high and rapid flux sequencing assays on the M. pneumoniae and further bioinformatic analysis, for the investigation of their clinical features and pathogenic characteristics. The results in this study on the clinical features and pathogenic characteristics of M. pneumoniae may further aid in the control and surveillance and better understanding of this pathogen.
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28
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Liu L, Lu Z, Li L, Li B, Zhang X, Zhang X, Xu Z. Physical relation and mechanism of ultrasonic bactericidal activity on pathogenic E. coli with WPI. Microb Pathog 2018; 117:73-79. [PMID: 29428425 DOI: 10.1016/j.micpath.2018.02.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 01/27/2018] [Accepted: 02/06/2018] [Indexed: 01/22/2023]
Abstract
OBJECTIVE This study aimed to investigate the physical relation and mechanism of bactericidal activity on pathogenic E. coli by ultrasonic field with whey protein isolate (WPI). METHODS Ultrasound treatment was performed under the conditions of intensity at 65 W/cm2, pulse duty ratio at 0.5 for 0-15 min with WPI concentration ranged from 0 to 10%. Viscosity, granularity, surface hydrophobicity, free radical scavenging activity, and thermal denaturation were assessed by rotational viscometer, Malvern Mastersizer 2000 particle size analyzer, fluorescent probe ANS method, DPPH method, and differential scanning calorimetry, respectively. RESULTS The thermal denaturation of WPI was not altered by ultrasound field, but the viscosity of WPI was increased upon 10 min treatment. Additionally, its ability to scavenge free radicals and hydrophobicity were increased. The result also showed that the bacteria viability was improved by WPI during ultrasound treatment. However, the WPI protection was decreased by the prolonged treatment. CONCLUSION Ultrasound treatment resulted in the increasing of the viscosity, free radicals scavenging activity and hydrophobicity of WPI which led to reduced bactericidal activity on E. coil, while WPI protection was disintegrated by prolonged treatment.
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Affiliation(s)
- Liyan Liu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, 510640, PR China
| | - Zerong Lu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China
| | - Lin Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, 510640, PR China
| | - Bing Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, 510640, PR China
| | - Xia Zhang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, 510640, PR China
| | - Ximei Zhang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China.
| | - Zhenbo Xu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, 510640, PR China; Department of Microbial Pathogenesis, University of Maryland, Baltimore, 21201, USA.
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Li Y, Bai C, Yang L, Fu J, Yan M, Chen D, Zhang L. High flux isothermal assays on pathogenic, virulent and toxic genetics from various pathogens. Microb Pathog 2018; 116:68-72. [PMID: 29325863 DOI: 10.1016/j.micpath.2018.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 01/02/2018] [Accepted: 01/07/2018] [Indexed: 11/17/2022]
Abstract
Toxins, encoding by virulence factors, are significant cause of food-borne illnesses and death in the worldwide. Loop-mediated isothermal amplification (LAMP) is one of the widely used methodologies because of the high sensitivity, specificity and rapidity. Nowadays, LAMP has been regarded as an innovative gene amplification technology and emerged as an alternative to PCR-based methodologies in identification of the pathogenic virulent and toxic genetics. The high sensitivity of LAMP enables detection of the pathogens in sample materials even without time consuming and sample preparation. Therefore, we review the typical characteristics of LAMP assay, recent advance in detection of virulence factors and the application of LAMP assay on detection of four commonly virulence factors. As concluded, with the advantages of rapidity, simplicity, sensitivity, specificity and robustness, LAMP is capable of identification the virulence factors. Moreover, the main purpose of this review is to provide theory support for the application of LAMP assay on the virulence factors identification.
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Affiliation(s)
- Yanmei Li
- Department of Haematology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China
| | - Caiying Bai
- Guangdong Women and Children Hospital, Guagzhou 510010, China
| | - Ling Yang
- Department of Laboratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
| | - Jie Fu
- Department of Haematology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China
| | - Muxia Yan
- Department of Haematology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China
| | - Dingqiang Chen
- Department of Laboratory Medicine, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China.
| | - Li Zhang
- Department of Haematology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China.
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Yin H, Dong J, Yu J, Li Y, Deng Y. A novel horA genetic mediated RCA detection of beer spoilage lactobacillus. Microb Pathog 2018; 114:311-314. [PMID: 29197525 DOI: 10.1016/j.micpath.2017.11.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 11/28/2017] [Accepted: 11/28/2017] [Indexed: 10/18/2022]
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Correlation and in vitro mechanism of bactericidal activity on E. coli with whey protein isolate during ultrasonic treatment. Microb Pathog 2017; 115:154-158. [PMID: 29278782 DOI: 10.1016/j.micpath.2017.12.062] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 12/20/2017] [Accepted: 12/20/2017] [Indexed: 12/12/2022]
Abstract
OBJECTIVE This study aimed to investigate correlation and in vitro mechanism of bactericidal activity on E. coli with whey protein isolate (WPI) during ultrasonic treatment. METHODS The structural changes of WPI under ultrasonic field were studied by amino-acid analyzer, circular dichroism, SDS-PAGE, and spectrophotometer. RESULTS With the increasing of WPI concentration added during ultrasonic treatment, the survival rate of E. coli increased. The influence of WPI on bactericidal activity under ultrasonic treatment might due to the change of tertiary and higher level structures, not by the primary structure, and had little relation with secondary structure. CONCLUSION The influence of WPI on bactericidal activity during ultrasonic treatment might due to the change of the tertiary structure and higher level structures.
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32
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Chen DQ, Jiang YT, Feng DH, Wen SX, Su DH, Yang L. Integron mediated bacterial resistance and virulence on clinical pathogens. Microb Pathog 2017; 114:453-457. [PMID: 29241766 DOI: 10.1016/j.micpath.2017.12.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/09/2017] [Accepted: 12/09/2017] [Indexed: 02/07/2023]
Abstract
Integron was recognized as mobile elements responsible for the emergence and diffusion of antibiotic resistance, virulence and pathogenicity. The existence of resistant integron in pathogens may consequently lead to the increasing number of clinical failures in bacterial mediated diseases, as well as the expenses. In this study, a total of 22 clinical pathogens (including E. faecalis, S. aureus, K. pneumoniae, Enterobacter, P. aeruginosa and Acinetobacter) were subjected to the identification of class 1-class 3 integrons and drug resistant gene cassettes by high flux LAMP method. According to the results, the clinical isolates were screened as carrying class 1 integron with dfrA12-orfF-aadA2 cassette array, class 1 integron with dfrA17-aadA5 cassette array, class 1 integron with aadA2 cassette, class 1 integron with blaVIM2 cassette, class 1 and class 2 integron with dfrA1-sat1-aadA1 and dfrA12-orfF-aadA2 cassette arrays simultaneously, which was accordantly with the previous data. The optimized high flux LAMP assay was proceeded in water bath at 65 °C for 60 min and determined by naked eye, with the time consumption restricted within 2.5 h. Prior to conventional PCR method, the high flux LAMP assay was demonstrated as a highly-specific and highly-sensitive method. This study offered a valid LAMP method in resistance integrons detection for laboratory use, which was time-saving and easy-determination.
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Affiliation(s)
- Ding-Qiang Chen
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China; Centre for Translational Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
| | - Yue-Ting Jiang
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
| | - Dong-Hua Feng
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China; Centre for Translational Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
| | - Shu-Xian Wen
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China; Centre for Translational Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
| | - Dan-Hong Su
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China
| | - Ling Yang
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China; Centre for Translational Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, China.
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Li Y, Yang L, Fu J, Yan M, Chen D, Zhang L. The novel loop-mediated isothermal amplification based confirmation methodology on the bacteria in Viable but Non-Culturable (VBNC) state. Microb Pathog 2017; 111:280-284. [DOI: 10.1016/j.micpath.2017.09.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 09/03/2017] [Accepted: 09/05/2017] [Indexed: 01/28/2023]
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Zhong H, Zhong Y, Deng Q, Zhou Z, Guan X, Yan M, Hu T, Luo M. Virulence of thermolable haemolysi tlh, gastroenteritis related pathogenicity tdh and trh of the pathogens Vibrio Parahemolyticus in Viable but Non-Culturable (VBNC) state. Microb Pathog 2017; 111:352-356. [DOI: 10.1016/j.micpath.2017.09.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 09/05/2017] [Accepted: 09/11/2017] [Indexed: 10/18/2022]
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35
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Microbial pathogenicity and virulence mediated by integrons on Gram-positive microorganisms. Microb Pathog 2017; 111:481-486. [PMID: 28923605 DOI: 10.1016/j.micpath.2017.09.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 09/13/2017] [Accepted: 09/14/2017] [Indexed: 11/22/2022]
Abstract
Gram-positive microorganisms are one of leading pathogenic microorganisms in public health, including several typical "Super Bugs" as methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae carbapenemase and vancomycin-resistant enterococci, which caused a increasement of infections, clinical failures and expenses. Regarded as a common genetic element responsible for horizontal gene transfer, integrons are widely distributed in various pathogens considered as a determinant in the acquisition and evolution of antibiotic resistance. Current investigations mainly focus on the distribution of integrons in Gram-negative microorganisms, while the role of integron in antibiotic resistance among Gram-positive microorganisms remains unclear and need investigation. To date, the surveillances of integrons in Gram-positive microorganism have been widely conducted in clinic, community even husbandry. China remains one of the worst country in antibiotics abuse worldwide and considered as a potential area for the prevalence of antimicrobial microorganisms and the occurrence of various 'Super Bugs'. Recently, the surveillance of the occurrence of integron and resistance gene cassettes was conducted in South China during the first 10 years of the 21st century. Referred to the surveillance in South China and other investigation in Asian countries, this review aims to summarize the occurrence, pathogenicity and virulence mediated by integrons in typical Gram-positive microorganisms (Staphylococcus, Enterococcus, Corynebacterium and Streptococcus) and the role of integrons in antibiotic resistance.
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Virulent and pathogenic features on the Cronobacter sakazakii polymyxin resistant pmr mutant strain s-3. Microb Pathog 2017; 110:359-364. [DOI: 10.1016/j.micpath.2017.07.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 11/18/2022]
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37
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Lin S, Yang L, Chen G, Li B, Chen D, Li L, Xu Z. Pathogenic features and characteristics of food borne pathogens biofilm: Biomass, viability and matrix. Microb Pathog 2017; 111:285-291. [PMID: 28803003 DOI: 10.1016/j.micpath.2017.08.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 08/06/2017] [Accepted: 08/07/2017] [Indexed: 11/16/2022]
Abstract
Biofilm is a ubiquitous growth pattern of bacterial species survival but is notorious for its threat on public health and food contamination. Extensive studies of the biofilm structure, formation, quantification, quorum sensing system and underlying control strategies have been reported during the past decades. Insightful elucidation of the pathogenic features and characteristic of bacterial biofilm can facilitate in devising appropriate control strategies for biofilm eradication. Therefore, this review mainly summarized the pathogenic features of biofilms from food borne microorganisms, including the biomass (which could be quantified using crystal violet and fluorogenic dye Syto9 assays), viability (which could be determined by tetrazolium salts, fluorescein diacetate, resazurin staining and alamar blue assays) and matrix (which are commonly detected by dimethyl methylene blue and wheat germ agglutinin assays). In addition, three features were further compared with its particular benefits in specific application.
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Affiliation(s)
- Shiqi Lin
- College of Food Sciences and Technology, South China University of Technology, Guangzhou 510640, China.
| | - Ling Yang
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
| | - Gu Chen
- College of Food Sciences and Technology, South China University of Technology, Guangzhou 510640, China.
| | - Bing Li
- College of Food Sciences and Technology, South China University of Technology, Guangzhou 510640, China.
| | - Dingqiang Chen
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
| | - Lin Li
- College of Food Sciences and Technology, South China University of Technology, Guangzhou 510640, China.
| | - Zhenbo Xu
- College of Food Sciences and Technology, South China University of Technology, Guangzhou 510640, China; Department of Microbial Pathogenesis, University of Maryland, Baltimore MD 21201, United States.
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