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Huang Y, Ji Y, Zheng M, Li X, Luan Y, Liu Y, Zhang X. Double-Enhanced Photothermal Lateral Flow Biosensor Based on Dual Gold Nanoparticle Conjugates. ACS Sens 2024; 9:2815-2825. [PMID: 38758028 DOI: 10.1021/acssensors.3c02329] [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] [Indexed: 05/18/2024]
Abstract
Bacterial toxins emerge as the primary triggers of foodborne illnesses, posing a significant threat to human health. To ensure food safety, it is imperative to implement point-of-care testing methods. Lateral flow biosensors (LFBs) based on gold nanoparticles (GNPs) have been commonly used for rapid detection, but their applicationis limited by low sensitivity. Based on the localized surface plasmon resonance and photothermal effect of dual gold nanoparticle conjugates (DGNPs), we developed a smartphone-integrated photothermal LFB (PLFB) with double-enhanced colorimetric and photothermal sensitivity. Through numerical simulations, we verified that DGNPs have significantly enhanced photothermal performance compared to single 15 nm GNPs (SGNPs), and applied DGNPs in PLFB for the detection of staphylococcus enterotoxin A (SEA). The colorimetric and photothermal limits of detection of DGNPs-based PLFB for SEA were 0.091 and 0.0038 ng mL-1, respectively. Compared with the colorimetric detection of the SGNPs-based LFB, the colorimetric detection sensitivity of the DGNPs-based PLFB was increased by 10.7 times, and the photothermal detection sensitivity was further improved by 255.3 times. Moreover, the PLFB exhibits robust reproducibility and exceptional specificity and is applicable for detecting SEA in milk samples. This smartphone-integrated PLFB based on DGNPs allows users to detect toxins simply, conveniently, and quickly and has huge application potential in the field of food safety.
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Affiliation(s)
- Yan Huang
- Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yongxiang Ji
- Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Mengxin Zheng
- SINOMACH Academy of Science and Technology Co., Ltd., Beijing 100083, China
| | - Xiujuan Li
- Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yi Luan
- Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yang Liu
- Beijing Key Laboratory for Bioengineering and Sensing Technology, School of Chemistry and Biological Engineering, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Xueji Zhang
- School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen 518060, China
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First Genome-Based Characterisation and Staphylococcal Enterotoxin Production Ability of Methicillin-Susceptible and Methicillin-Resistant Staphylococcus aureus Strains Isolated from Ready-to-Eat Foods in Algiers (Algeria). Toxins (Basel) 2022; 14:toxins14110731. [PMID: 36355981 PMCID: PMC9694651 DOI: 10.3390/toxins14110731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 01/26/2023] Open
Abstract
Staphylococcus aureus is a pathogenic microorganism of humans and animals, able to cause foodborne intoxication due to the production of staphylococcal enterotoxins (SEs) and to resist antibiotic treatment as in the case of methicillin-resistant S. aureus (MRSA). In this study, we performed a genomic characterisation of 12 genetically diverse S. aureus strains isolated from ready-to-eat foods in Algiers (Algeria). Moreover, their ability to produce some classical and new staphylococcal enterotoxins (SEs) was investigated. The 12 S. aureus strains resulted to belong to nine known sequence types (STs) and to the novel ST7199 and ST7200. Furthermore, S. aureus SA46 was assigned to the European clone MRSA-ST80-SCCmec-IV. The 12 strains showed a wide endowment of se and sel (staphylococcal enterotoxin-like toxin) genes (sea, seb, sed, seg, seh, sei, selj, sek, sem, sen, seo, seq, ser, selu2, selw, selx, sey, sel30; ψent1-ψent2), including variants and pseudogenes, and harboured the enterotoxin gene cluster (egc) types 1 and 5. Additionally, they produced various amounts of SEA (64.54-345.02 ng/mL), SEB (2871.28-14739.17 ng/mL), SED (322.70-398.94 ng/mL), SEH (not detectable-239.48 ng/mL), and SER (36,720.10-63,176.06 ng/mL) depending on their genotypes. The genetic determinants related to their phenotypic resistance to β-lactams (blaZ, mecA), ofloxacin (gyrA-S84L), erythromycin (ermB), lincomycin (lmrS), kanamycin (aph(3')-III, ant(6)-I), and tetracyclin (tet(L), tet(38)) were also detected. A plethora of virulence-related genes, including major virulence genes such as the tst gene, determinant for the toxic shock syndrome toxin-1, and the lukF-PV and lukS-PV genes, encoding the panton-valentine leukocidin (PVL), were present in the S. aureus strains, highlighting their pathogenic potential. Furthermore, a phylogenomic reconstruction including worldwide foodborne S. aureus showed a clear clustering based on ST and geographical origin rather than the source of isolation.
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Effects of Growth Stage on the Characterization of Enterotoxin A-Producing Staphylococcus aureus‐Derived Membrane vesicles. Microorganisms 2022; 10:microorganisms10030574. [PMID: 35336149 PMCID: PMC8948643 DOI: 10.3390/microorganisms10030574] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/02/2022] [Accepted: 03/04/2022] [Indexed: 11/17/2022] Open
Abstract
Virulence factors, such as staphylococcal enterotoxin A (SEA), are contained within membrane vesicles (MVs) in the cell membrane of Staphylococcus aureus. In this study, the effects of the growth stage on quantitative and qualitative changes in the components contained in the MVs of S. aureus SEA-producing strains were examined. Changes in the expression levels of S. aureus genes were examined at each growth stage; phenol-soluble modulin (PSM) gene reached a maximum after 8 h, and the expression of cell membrane-related genes was decreased after 6 h. Based on these gene expression patterns, MVs were prepared at 6, 17, and 24 h. The particle size of MVs did not change depending on the growth stage. MVs prepared after culture for 17 h maintained their particle size when stored at 23 °C. The amount of SEA in the culture supernatant and MVs were not correlated. Bifunctional autolysin, a protein involved in cell wall biosynthesis/degradation, was increased in MVs at 17 h. The expression pattern of inflammation-related genes in human adult low calcium high temperature (HaCaT) cells induced by MVs was different for each growth stage. The inclusion components of S. aureus-derived MVs are selective, depend on the stage of growth, and may play an important role in toxicity.
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Mahmoodi Sadr M, Shakerian A, Rahimi E, Momtaz H. Retracted
: Antibiotic resistance properties and genotypic characterization of enterotoxins in the
Staphylococcus aureus
strains isolated from traditional sweets. J Food Saf 2018. [DOI: 10.1111/jfs.12573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mohammadreza Mahmoodi Sadr
- Research Center of Nutrition and Organic ProductsShahrekord Branch, Islamic Azad University Shahrekord Iran
- Department of Food Hygiene, Faculty of Veterinary Medicine, Shahrekord BranchIslamic Azad University Shahrekord Iran
| | - Amir Shakerian
- Research Center of Nutrition and Organic ProductsShahrekord Branch, Islamic Azad University Shahrekord Iran
- Department of Food Hygiene, Faculty of Veterinary Medicine, Shahrekord BranchIslamic Azad University Shahrekord Iran
| | - Ebrahim Rahimi
- Research Center of Nutrition and Organic ProductsShahrekord Branch, Islamic Azad University Shahrekord Iran
- Department of Food Hygiene, Faculty of Veterinary Medicine, Shahrekord BranchIslamic Azad University Shahrekord Iran
| | - Hasan Momtaz
- Department of PathobiologyFaculty of Veterinary Medicine, Shahrekord Branch, Islamic Azad University Shahrekord Iran
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Wu X, Yang M, Fang X, Zhen S, Zhang J, Yang X, Qiao L, Yang Y, Zhang C. Expression and regulation of phenol-soluble modulins and enterotoxins in foodborne Staphylococcus aureus. AMB Express 2018; 8:187. [PMID: 30467730 PMCID: PMC6250609 DOI: 10.1186/s13568-018-0717-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/17/2018] [Indexed: 12/15/2022] Open
Abstract
Although high levels of staphylococcal phenol-soluble modulins (PSMs) in clinical methicillin-resistant Staphylococcus aureus (MRSA) has been shown to correlate with bacterial virulence, the PSMs expression in foodborne Staphylococcus aureus (S. aureus), as well as its association with staphylococcal food poisoning (SFP) was not yet clear. We collected a panel of 350 foodborne and 127 clinic-derived S. aureus strains and compared their PSMs expression. Overall, foodborne strains exhibited higher PSMs than clinical isolates, indicating a potential pathological significance of PSMs in staphylococcal food contamination. Furthermore, PSMs expression and staphylococcal enterotoxins (SEs) levels in relation to antibiotic sensitive and resistant strains were analysed. While the co-expression of PSMs and SEs was confirmed, one typical foodborne strain simultaneously yielding PSMs, SEB and SED was selected. By comparing this wildtype strain to a series of gene-deficient mutants, we concluded that PSMs and SEs expressions both relied on staphylococcal accessory regulator A initiation in the early stage of accessory gene regulator control, yet their succedent regulations differentiated to RNAIII-dependent and independent, respectively. These data provided preliminary insight into PSMs and SEs expression in foodborne S. aureus, and may guide the further studies on PSMs effects in SFP.
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Wu S, Huang J, Wu Q, Zhang J, Zhang F, Yang X, Wu H, Zeng H, Chen M, Ding Y, Wang J, Lei T, Zhang S, Xue L. Staphylococcus aureus Isolated From Retail Meat and Meat Products in China: Incidence, Antibiotic Resistance and Genetic Diversity. Front Microbiol 2018; 9:2767. [PMID: 30498486 PMCID: PMC6249422 DOI: 10.3389/fmicb.2018.02767] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/29/2018] [Indexed: 12/27/2022] Open
Abstract
This study was to estimate the prevalence and characteristics of Staphylococcus aureus from 1,850 retail meat and meat products in China during July 2011 to June 2016. The samples were collected covering most provincial capitals in China, including 604 raw meat, 601 quick-frozen meat, and 645 ready-to-eat meat. Using the qualitative and quantitative methods, all 39 cities had S. aureus-positive samples, and S. aureus was detected in 35.0% (647/1,850) of the samples. The levels of S. aureus in retail meat showed that the MPN value of the majority of the positive samples ranged from 0.3 to 100 MPN/g. Twenty-four antibiotics were used to test all 868 S. aureus isolates for antibiotic susceptibility. Only 11 isolates (1.26%) were susceptible to all antibiotics, whereas most isolates (821/868, 94.6%) showed resistance or intermediary resistance to more than three or more antibiotics. Of these strains, 104 (12.0%) were resistant to more than 10 antibiotics. However, the most frequent resistance was observed to ampicillin (85.4%), followed by penicillin (84.6%), erythromycin (52.7%), tetracycline (49.3%), kanamycin (45.3%), telithromycin (30.1%), clindamycin (29.6%), streptomycin (21.1%), norfloxacin (20.4%), gentamicin (19.4%), fusidic acid (18.4%), ciprofloxacin (16.9%), chloramphenicol (13.1%), amoxycillin/clavulanic acid (11.0%), and others (<10%). 7.4% of isolates (62/868) were confirmed as methicillin-resistance S. aureus (MRSA). By molecular typing analysis, there were 164 spa types and 111 STs were identified, including 15 novel spa types and 65 newly STs by multilocus sequence typing (MLST) and spa typing. Despite the wide genetic diversity observed among the 868 isolates, a great proportion of the population belonged to finite number of major clones: ST1-t127 (93/868, 10.7%) and ST7-t091 (92/868, 10.6%), ST5-t002 (42/868, 4.8%), ST398-t034 (40/868, 4.6%), ST188-t034 (38/868, 4.4%), ST59-t437 (30/868, 3.5%), ST6-t701 (29/868, 3.3%), and ST9-t899 (27/868, 3.1%) in China. This study reflects S. aureus was readily detected in Chinese retail meat and meat products but the level were not very excessive. In this study, the high antibiotic resistance is alarming and raising public health concern. In additions, most of molecular types of isolates have been linked to human infections around the world, indicating that these types of S. aureus in China have a theoretical pathogenic potential.
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Affiliation(s)
- Shi Wu
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Jiahui Huang
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Qingping Wu
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Jumei Zhang
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Feng Zhang
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China.,School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Xiaojuan Yang
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Haoming Wu
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Haiyan Zeng
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Moutong Chen
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Yu Ding
- Department of Food Science & Technology, Jinan University, Guangzhou, China
| | - Juan Wang
- College of Food Science, South China Agricultural University, Guangzhou, China
| | - Tao Lei
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Shuhong Zhang
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
| | - Liang Xue
- Guangdong Institute of Microbiology, State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangzhou, China
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7
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Yang X, Yu S, Wu Q, Zhang J, Wu S, Rong D. Multilocus Sequence Typing and Virulence-Associated Gene Profile Analysis of Staphylococcus aureus Isolates From Retail Ready-to-Eat Food in China. Front Microbiol 2018; 9:197. [PMID: 29662467 PMCID: PMC5890145 DOI: 10.3389/fmicb.2018.00197] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/29/2018] [Indexed: 11/25/2022] Open
Abstract
The aim of this study was to characterize the subtypes and virulence profiles of 69 Staphylococcus aureus isolates obtained from retail ready-to-eat food in China. The isolates were analyzed using multilocus sequence typing (MLST) and polymerase chain reaction (PCR) analysis of important virulence factor genes, including the staphylococcal enterotoxin (SE) genes (sea, seb, sec, sed, see, seg, seh, sei, sej), the exfoliative toxin genes (eta and etb), the toxic shock syndrome toxin-1 gene (tst), and the Panton-Valentine leucocidin-encoding gene (pvl). The isolates encompassed 26 different sequence types (STs), including four new STs (ST3482, ST3484, ST3485, ST3504), clustered in three clonal complexes and 17 singletons. The most prevalent STs were ST1, ST6, and ST15, constituting 34.8% of all isolates. Most STs (15/26, 57.7%) detected have previously been associated with human infections. All 13 toxin genes examined were detected in the S. aureus isolates, with 84.1% of isolates containing toxin genes. The three most prevalent toxin genes were seb (36.2%), sea (33.3%), and seg (33.3%). The classical SE genes (sea–see), which contribute significantly to staphylococcal food poisoning (SFP), were detected in 72.5% of the S. aureus isolates. In addition, pvl, eta, etb, and tst were found in 11.6, 10.1, 10.1, and 7.2% of the S. aureus isolates, respectively. Strains ST6 carrying sea and ST1 harboring sec-seh enterotoxin profile, which are the two most common clones associated with SFP, were also frequently detected in the food samples in this study. This study indicates that these S. aureus isolates present in Chinese ready-to-eat food represents a potential public health risk. These data are valuable for epidemiological studies, risk management, and public health strategies.
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Affiliation(s)
- Xiaojuan Yang
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Shubo Yu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Qingping Wu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Jumei Zhang
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Shi Wu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Dongli Rong
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
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Ou Q, Peng Y, Lin D, Bai C, Zhang T, Lin J, Ye X, Yao Z. A Meta-Analysis of the Global Prevalence Rates of Staphylococcus aureus and Methicillin-Resistant S. aureus Contamination of Different Raw Meat Products. J Food Prot 2017; 80:763-774. [PMID: 28358261 DOI: 10.4315/0362-028x.jfp-16-355] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 12/12/2016] [Indexed: 01/29/2023]
Abstract
Previous research has indicated that raw meats are frequently contaminated with Staphylococcus aureus, but data regarding the pooled prevalence rates of S. aureus and methicillin-resistant S. aureus (MRSA) contamination in different types of raw meat products (beef, chicken, and pork) and across different periods, regions, and purchase locations remain inconsistent. We systematically searched the PubMed, EMBASE, Ovid, Web of Science, and HighWire databases to identify studies published up to June 2016. The STROBE guidelines were used to assess the quality of the 39 studies included in this meta-analysis. We observed no significant differences in the pooled prevalence rates of S. aureus and MRSA contamination identified in various raw meat products, with overall pooled prevalence rates of 29.2% (95% confidence interval [CI], 22.8 to 35.9%) and 3.2% (95% CI, 1.8 to 4.9%) identified for the two contaminants, respectively. In the subgroup analyses, the prevalence of S. aureus contamination in chicken products was highest in Asian studies and significantly decreased over time worldwide. In European studies, the prevalence rates of S. aureus contamination in chicken and pork products were lower than those reported on other continents. The pooled prevalence rates of S. aureus contamination in chicken and pork products and MRSA contamination in beef and pork products were significantly higher in samples collected from retail sources than in samples collected from slaughterhouses and processing plants. These results highlight the need for good hygiene during transportation to and manipulation at retail outlets to reduce the risk of transmission of S. aureus and MRSA from meat products to humans.
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Affiliation(s)
- Qianting Ou
- Department of Epidemiology and Health Statistics, Public Health School, Guangdong Pharmaceutical University, Guangzhou 510310, People's Republic of China; and
| | - Yang Peng
- Centre for Chronic Diseases, University of Queensland, Brisbane, Queensland, Australia
| | - Dongxin Lin
- Department of Epidemiology and Health Statistics, Public Health School, Guangdong Pharmaceutical University, Guangzhou 510310, People's Republic of China; and
| | - Chan Bai
- Department of Epidemiology and Health Statistics, Public Health School, Guangdong Pharmaceutical University, Guangzhou 510310, People's Republic of China; and
| | - Ting Zhang
- Department of Epidemiology and Health Statistics, Public Health School, Guangdong Pharmaceutical University, Guangzhou 510310, People's Republic of China; and
| | - Jialing Lin
- Department of Epidemiology and Health Statistics, Public Health School, Guangdong Pharmaceutical University, Guangzhou 510310, People's Republic of China; and
| | - Xiaohua Ye
- Department of Epidemiology and Health Statistics, Public Health School, Guangdong Pharmaceutical University, Guangzhou 510310, People's Republic of China; and
| | - Zhenjiang Yao
- Department of Epidemiology and Health Statistics, Public Health School, Guangdong Pharmaceutical University, Guangzhou 510310, People's Republic of China; and
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9
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Nagaraj S, Ramlal S, Kingston J, Batra HV. Development of IgY based sandwich ELISA for the detection of staphylococcal enterotoxin G (SEG), an egc toxin. Int J Food Microbiol 2016; 237:136-141. [DOI: 10.1016/j.ijfoodmicro.2016.08.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 11/30/2022]
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10
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Song M, Shi C, Xu X, Shi X. Molecular Typing and Virulence Gene Profiles of Enterotoxin Gene Cluster (egc)-Positive Staphylococcus aureus Isolates Obtained from Various Food and Clinical Specimens. Foodborne Pathog Dis 2016; 13:592-601. [PMID: 27792397 DOI: 10.1089/fpd.2016.2162] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The enterotoxin gene cluster (egc) has been proposed to contribute to the Staphylococcus aureus colonization, which highlights the need to evaluate genetic diversity and virulence gene profiles of the egc-positive population. Here, a total of 43 egc-positive isolates (16.2%) were identified from 266 S. aureus isolates that were obtained from various food and clinical specimens in Shanghai. Seven different egc profiles were found based on the polymerase chain reaction (PCR) result for egc genes. Then, these 43 egc-positive isolates were further typed by multilocus sequence typing, pulsed-field gel electrophoresis (PFGE), multiple-locus variable-number tandem-repeat analysis (MLVA), and accessory gene regulatory (agr) typing. It showed that the 43 egc-positive isolates displayed 17 sequence types, 28 PFGE patterns, 29 MLVA types, and 4 agr types, respectively. Among them, the dominant clonal lineage was CC5-agr II (48.84%). Thirty toxin and 20 adhesion-associated genes were detected by PCR in egc-positive isolates. Notably, invasive toxin genes showed a high prevalence, such as 76.7% for Panton-Valentine leukocidin encoding genes, 27.9% for sec, and 23.3% for tsst-1. Most of the examined adhesion-associated genes were found to be conserved (76.7-100%), whereas the fnbB gene was only found in 8 (18.6%) isolates. In addition, 33 toxin gene profiles and 13 adhesion gene profiles were identified, respectively. Our results imply that isolates belonging to the same clonal lineage harbored similar adhesion gene profiles but diverse toxin gene profiles. Overall, the high prevalence of invasive virulence genes increases the potential risk of egc-positive isolates in S. aureus infection.
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Affiliation(s)
- Minghui Song
- 1 MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University , Shanghai, P.R. China
| | - Chunlei Shi
- 1 MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University , Shanghai, P.R. China
| | - Xuebing Xu
- 2 Shanghai Municipal Center for Disease Control and Prevention , Shanghai, P.R. China
| | - Xianming Shi
- 1 MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University , Shanghai, P.R. China
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11
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Li F, Zuo S, Yu P, Zhou B, Wang L, Liu C, Wei H, Hengyi Xu. Distribution and expression of the enterotoxin genes of Bacillus cereus in food products from Jiangxi Province, China. Food Control 2016. [DOI: 10.1016/j.foodcont.2016.02.049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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12
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Kroning IS, Iglesias MA, Sehn CP, Valente Gandra TK, Mata MM, da Silva WP. Staphylococcus aureus isolated from handmade sweets: Biofilm formation, enterotoxigenicity and antimicrobial resistance. Food Microbiol 2016; 58:105-11. [PMID: 27217365 DOI: 10.1016/j.fm.2016.04.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 03/17/2016] [Accepted: 04/01/2016] [Indexed: 11/25/2022]
Abstract
Staphylococcus aureus is the second most important pathogen involved in foodborne outbreaks in Brazil. Because of their widespread distribution and biofilm forming ability, handmade sweets are easily contaminated with S. aureus. The aim of this study was to isolate and identify coagulase-positive staphylococci (CPS) from handmade sweets produced in Pelotas City/Brazil. The virulence potential was checked by evaluating the presence of the staphylococcal enterotoxin genes, icaA and icaD genes, the biofilm forming potential and antimicrobial resistance of the isolates. It was find just S. aureus among the CPS isolates. All the S. aureus isolates had biofilm forming ability on stainless steel and more than half of them on polystyrene surfaces. The majority of the isolates carried the icaA (66.6%) and icaD (58.4%) genes and some of them had the genes encoding enterotoxins A (33.4%) and B (16.6%). Furthermore, the majority of the isolates (83%) were resistant to at least one of the tested antimicrobials and multidrug resistance was observed in 8.4% of the isolates. The isolates had virulence potential, and half of them were enterotoxigenic. In addition, the ability of all the isolates to produce biofilms highlights the danger posed by these potentially virulent microorganisms persisting in food manufacturing environments.
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Affiliation(s)
- Isabela Schneid Kroning
- Science and Agroindustrial Technology Department, Federal University of Pelotas, Pelotas, RS, Brazil.
| | - Mariana Almeida Iglesias
- Biotechnology Unit, Technology Development Center, Federal University of Pelotas, Pelotas, RS, Brazil.
| | | | | | - Marcia Magalhães Mata
- Science and Agroindustrial Technology Department, Federal University of Pelotas, Pelotas, RS, Brazil.
| | - Wladimir Padilha da Silva
- Science and Agroindustrial Technology Department, Federal University of Pelotas, Pelotas, RS, Brazil; Biotechnology Unit, Technology Development Center, Federal University of Pelotas, Pelotas, RS, Brazil.
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Viçosa GN, Le Loir A, Le Loir Y, de Carvalho AF, Nero LA. egc characterization of enterotoxigenic Staphylococcus aureus isolates obtained from raw milk and cheese. Int J Food Microbiol 2013; 165:227-30. [PMID: 23800734 DOI: 10.1016/j.ijfoodmicro.2013.05.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/27/2013] [Accepted: 05/28/2013] [Indexed: 11/19/2022]
Abstract
Genes encoding staphylococcal enterotoxins (SEs) are carried by mobile genetic elements, and enterotoxin gene clusters (egc) are pathogenicity island-borne structures comprising several SE genes, which are frequently found among clinical Staphylococcus aureus isolates. In the present study, we investigated the distribution and the genetic variability of egc loci in S. aureus strains isolated from raw milk and soft cheese in Minas Gerais, Brazil. Ninety-two isolates were submitted to PCR detection of individual egc-borne SE genes (seg, sei, sem, sen, seo, seu), and egc loci were typed using PCR-RFLP. PCR products of egc positive isolates were sequenced. Ninety-one isolates harbored at least one SE gene, which generated 14 different genotypes. The sei gene was the most widely distributed (97.8%), and was found in combination with seg in 49 isolates (53.3%). Altogether, a complete set of individual egc genes was detected in 37 isolates (40%). However, egc loci were detected by PCR-RFLP in only 4 isolates, and classified as egc1 (n=2), egc3 (n=1), and egc4 (n=1). This investigation demonstrated the low occurrence of the egc in S. aureus isolated from dairy products. However, the frequency of complete sets of individual egc-borne genes reflects either the presence of these SE genes outside egc or the existence of new egc types in these strains.
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