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Piazza RM, Caetano BA, Henrique CP, Luz D, Munhoz DD, Polatto JM, Rocha LB, Silva MA, Mitsunari T. Immunological tests for diarrhoea caused by diarrhoeagenic Escherichia coli targeting their main virulence factors. J Microbiol Methods 2020. [DOI: 10.1016/bs.mim.2019.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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2
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Silva MA, Santos ARR, Rocha LB, Caetano BA, Mitsunari T, Santos LI, Polatto JM, Horton DSPQ, Guth BEC, Dos Santos LF, Piazza RMF. Development and Validation of Shiga Toxin-Producing Escherichia coli Immunodiagnostic Assay. Microorganisms 2019; 7:E276. [PMID: 31438570 PMCID: PMC6780578 DOI: 10.3390/microorganisms7090276] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 01/29/2023] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) and its subgroup enterohemorrhagic E. coli are important pathogens involved in diarrhea, which may be complicated by hemorrhagic colitis and hemolytic uremic syndrome, the leading cause of acute renal failure in children. Early diagnosis is essential for clinical management, as an antibiotic treatment in STEC infections is not recommended. Previously obtained antibodies against Stx1 and Stx2 toxins were employed to evaluate the sensitivity and specificity of the latex Agglutination test (LAT), lateral flow assay (LFA), and capture ELISA (cEIA) for STEC detection. The LAT (mAb Stx1 plus mAb stx2) showed 99% sensitivity and 97% specificity. Individually, Stx1 antibodies showed 95.5% and 94% sensitivity and a specificity of 97% and 99% in the cEIA and LFA assay, respectively. Stx2 antibodies showed a sensitivity of 92% in both assays and a specificity of 100% and 98% in the cEIA and LFA assay, respectively. These results allow us to conclude that we have robust tools for the diagnosis of STEC infections.
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Affiliation(s)
- Miriam A Silva
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | | | - Leticia B Rocha
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Bruna A Caetano
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Thais Mitsunari
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Luanda I Santos
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Juliana M Polatto
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Denise S P Q Horton
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil
| | - Beatriz E C Guth
- Departamento de Microbiologia, Imunologia, Parasitologia, Escola Paulista de Medicina Universidade Federal de São Paulo, São Paulo 04023-062, Brasil
| | | | - Roxane M F Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo 05503-900, Brasil.
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3
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Yamamoto BB, Luz D, Abreu PAE, Gotti TB, Vasconcellos SA, Piazza RMF, Horton DSPQ. Antibodies to Shiga toxins in Brazilian cattle. Toxicon 2017; 133:58-62. [PMID: 28454739 DOI: 10.1016/j.toxicon.2017.04.014] [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: 02/16/2017] [Revised: 04/20/2017] [Accepted: 04/21/2017] [Indexed: 11/17/2022]
Abstract
Cattle are considered a reservoir of Shiga toxin-producing Escherichia coli (STEC). There is no information about the presence of antibodies against Shiga toxins in Brazilian bovine serum. Using ELISA, all sera tested showed antibodies against the two main STEC virulence factors; Stx1 and Stx2. Neutralizing antibodies against Stx1 and/or Stx2 were detected in all but one serum. In conclusion, our results indicated that these animals had been exposed to STEC producing both toxins.
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Affiliation(s)
- Bruno B Yamamoto
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Daniela Luz
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | | | - Tatiana B Gotti
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Silvio A Vasconcellos
- Laboratório de Zoonoses Bacterianas, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
| | - Roxane M F Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil.
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Gomes TAT, Elias WP, Scaletsky ICA, Guth BEC, Rodrigues JF, Piazza RMF, Ferreira LCS, Martinez MB. Diarrheagenic Escherichia coli. Braz J Microbiol 2016; 47 Suppl 1:3-30. [PMID: 27866935 PMCID: PMC5156508 DOI: 10.1016/j.bjm.2016.10.015] [Citation(s) in RCA: 252] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 10/27/2016] [Indexed: 12/22/2022] Open
Abstract
Most Escherichia coli strains live harmlessly in the intestines and rarely cause disease in healthy individuals. Nonetheless, a number of pathogenic strains can cause diarrhea or extraintestinal diseases both in healthy and immunocompromised individuals. Diarrheal illnesses are a severe public health problem and a major cause of morbidity and mortality in infants and young children, especially in developing countries. E. coli strains that cause diarrhea have evolved by acquiring, through horizontal gene transfer, a particular set of characteristics that have successfully persisted in the host. According to the group of virulence determinants acquired, specific combinations were formed determining the currently known E. coli pathotypes, which are collectively known as diarrheagenic E. coli. In this review, we have gathered information on current definitions, serotypes, lineages, virulence mechanisms, epidemiology, and diagnosis of the major diarrheagenic E. coli pathotypes.
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Affiliation(s)
- Tânia A T Gomes
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil.
| | - Waldir P Elias
- Instituto Butantan, Laboratório de Bacterologia, São Paulo, SP, Brazil
| | - Isabel C A Scaletsky
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil
| | - Beatriz E C Guth
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil
| | - Juliana F Rodrigues
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Roxane M F Piazza
- Instituto Butantan, Laboratório de Bacterologia, São Paulo, SP, Brazil
| | - Luís C S Ferreira
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Marina B Martinez
- Universidade de São Paulo, Faculdade de Ciências Farmacêuticas, Departamento de Análises Clínicas e Toxicológicas, São Paulo, SP, Brazil
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Luz D, Chen G, Maranhão AQ, Rocha LB, Sidhu S, Piazza RMF. Development and characterization of recombinant antibody fragments that recognize and neutralize in vitro Stx2 toxin from Shiga toxin-producing Escherichia coli. PLoS One 2015; 10:e0120481. [PMID: 25790467 PMCID: PMC4366190 DOI: 10.1371/journal.pone.0120481] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/22/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Stx toxin is a member of the AB5 family of bacterial toxins: the active A subunit has N-glycosidase activity against 28S rRNA, resulting in inhibition of protein synthesis in eukaryotic cells, and the pentamer ligand B subunits (StxB) bind to globotria(tetra)osylceramide receptors (Gb3/Gb4) on the cell membrane. Shiga toxin-producing Escherichia coli strains (STEC) may produce Stx1 and/or Stx2 and variants. Strains carrying Stx2 are considered more virulent and related to the majority of outbreaks, besides being usually associated with hemolytic uremic syndrome in humans. The development of tools for the detection and/or neutralization of these toxins is a turning point for early diagnosis and therapeutics. Antibodies are an excellent paradigm for the design of high-affinity, protein-based binding reagents used for these purposes. METHODS AND FINDINGS In this work, we developed two recombinant antibodies; scFv fragments from mouse hybridomas and Fab fragments by phage display technology using a human synthetic antibody library. Both fragments showed high binding affinity to Stx2, and they were able to bind specifically to the GKIEFSKYNEDDTF region of the Stx2 B subunit and to neutralize in vitro the cytotoxicity of the toxin up to 80%. Furthermore, the scFv fragments showed 79% sensitivity and 100% specificity in detecting STEC strains by ELISA. CONCLUSION In this work, we developed and characterized two recombinant antibodies against Stx2, as promising tools to be used in diagnosis or therapeutic approaches against STEC, and for the first time, we showed a human monovalent molecule, produced in bacteria, able to neutralize the cytotoxicity of Stx2 in vitro.
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Affiliation(s)
- Daniela Luz
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Gang Chen
- Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
| | | | - Leticia B. Rocha
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Sachdev Sidhu
- Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada
| | - Roxane M. F. Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
- * E-mail:
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Fernandes MR, Ignacio A, Martins FH, Rocha LB, Piazza RMF, Vaz TMI, Avila-Campos MJ, Nakano V. Presence of Shiga toxin 2e-producing Escherichia coli and atypical enteropathogenic E. coli in an asymptomatic child. JMM Case Rep 2014; 1:e000001. [PMID: 28663801 PMCID: PMC5415922 DOI: 10.1099/jmmcr.0.000001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 10/21/2014] [Indexed: 11/21/2022] Open
Abstract
Introduction: Escherichia coli causes gastroenteritis in humans and animals. Case presentation: In this study, both Shiga toxin-producing E. coli (STEC) and atypical enteropathogenic E. coli (EPEC) strains were identified in a stool sample from a healthy child, and they were serotyped as Shiga toxin-producing E. coli (STEC) ONT : H19 and atypical enteropathogenic E. coli (EPEC) O37 : H45. Conclusion: This is the first report, to our knowledge, of a concomitant presence of diarrhoeagenic E. coli (DEC) strains in an asymptomatic child. None of the microorganisms was able to produce diarrhoea, maybe because they were transient bacteria or because of the good immune status of the child. Attention should be paid to this result and it could be of interest in vaccine prospects.
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Affiliation(s)
- Miriam Rodriguez Fernandes
- Anaerobe Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil
| | - Aline Ignacio
- Anaerobe Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil
| | | | - Leticia B Rocha
- Bacteriology Laboratory, Butantan Institute, São Paulo, Brazil
| | | | - Tânia M I Vaz
- Bacteriology Laboratory, Adolfo Lutz Institute, São Paulo, Brazil
| | - Mario Julio Avila-Campos
- Anaerobe Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil
| | - Viviane Nakano
- Anaerobe Laboratory, Department of Microbiology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil
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Jenko KL, Zhang Y, Kostenko Y, Fan Y, Garcia-Rodriguez C, Lou J, Marks JD, Varnum SM. Development of an ELISA microarray assay for the sensitive and simultaneous detection of ten biodefense toxins. Analyst 2014; 139:5093-102. [PMID: 25112421 PMCID: PMC6540756 DOI: 10.1039/c4an01270d] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plant and microbial toxins are considered bioterrorism threat agents because of their extreme toxicity and/or ease of availability. Additionally, some of these toxins are increasingly responsible for accidental food poisonings. The current study utilized an ELISA-based protein antibody microarray for the multiplexed detection of ten biothreat toxins, botulinum neurotoxins (BoNT) A, B, C, D, E, F, ricin, shiga toxins 1 and 2 (Stx), and staphylococcus enterotoxin B (SEB), in buffer and complex biological matrices. The multiplexed assay displayed a sensitivity of 1.3 pg mL(-1) (BoNT/A, BoNT/B, SEB, Stx-1 and Stx-2), 3.3 pg mL(-1) (BoNT/C, BoNT/E, BoNT/F) and 8.2 pg mL(-1) (BoNT/D, ricin). All assays demonstrated high accuracy (75-120 percent recovery) and reproducibility (most coefficients of variation <20%). Quantification curves for the ten toxins were also evaluated in clinical samples (serum, plasma, nasal fluid, saliva, stool, and urine) and environmental samples (apple juice, milk and baby food) with overall minimal matrix effects. The multiplex assays were highly specific, with little cross-reactivity observed between the selected toxin antibodies. The results demonstrate a multiplex microarray that improves current immunoassay sensitivity for biological warfare agents in buffer, clinical, and environmental samples.
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Affiliation(s)
- Kathryn L Jenko
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, USA.
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Interaction between Shiga toxin and monoclonal antibodies: binding characteristics and in vitro neutralizing abilities. Toxins (Basel) 2012; 4:729-47. [PMID: 23105978 PMCID: PMC3475226 DOI: 10.3390/toxins4090729] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 09/17/2012] [Accepted: 09/17/2012] [Indexed: 11/17/2022] Open
Abstract
Monoclonal antibodies (MAbs) have been employed either for diagnosis or treatment of infections caused by different pathogens. Specifically for Shiga toxin-producing Escherichia coli (STEC), numerous immunoassays have been developed for STEC diagnosis, showing variability in sensitivity and specificity when evaluated by reference laboratories, and no therapy or vaccines are currently approved. Thus, the aim of this work was the characterization of the interaction between MAbs against Stx1 and Stx2 toxins and their neutralizing abilities to enable their use as tools for diagnosis and therapy. The selected clones designated 3E2 (anti-Stx1) and 2E11 (anti-Stx2) were classified as IgG1. 3E2 recognized the B subunit of Stx1 with an affinity constant of 2.5 × 10−10 M, detected as little as 6.2 ng of Stx1 and was stable up to 50 ºC. In contrast, 2E11 recognized the A subunit of Stx2, was stable up to 70 ºC, had a high dissociation constant of 6.1 × 10−10 M, and detected as little as 12.5 ng of Stx2. Neutralization tests showed that 160 ng of 3E2 MAb inhibited 80% of Stx1 activity and 500 µg 2E11 MAb were required for 60% inhibition of Stx2 activity. These MAb amounts reversed 25 to 80% of the cytotoxicity triggered by different STEC isolates. In conclusion, these MAbs show suitable characteristics for their use in STEC diagnosis and encourage future studies to investigate their protective efficacy.
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Ferreira T, De Gaspari E. The design of new adjuvants for mucosal immunity to Neisseria meningitidis B in nasally primed neonatal mice for adult immune response. ScientificWorldJournal 2012; 2012:292073. [PMID: 22545012 PMCID: PMC3324212 DOI: 10.1100/2012/292073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 11/30/2011] [Indexed: 02/03/2023] Open
Abstract
The aim of this study was to determine the value of detoxified Shiga toxins Stx1 and Stx2 (toxoids of Escherichia coli) as mucosal adjuvants in neonatal mice for immunogenicity against the outer membrane proteins (OMPs) of Neisseria meningitidis B. Mucosal immunization has been shown to be effective for the induction of antigen-specific immune responses in both the systemic and mucosal compartments. Systemic antibody levels (IgG, IgG1, IgG2a, IgG2b, IgM, and IgA) and mucosal IgM and IgA were measured by ELISA using an N. meningitidis as an antigen. In addition, IFN-γ and IL-6 production were measured after stimulated proliferation of immune cells. Intranasal administration elicited a higher anti-OMP IgA response in both saliva and vaginal fluids. Our results suggest that both Stx1 and Stx2 toxoids are effective mucosal adjuvants for the induction of Ag-specific IgG, IgM, and IgA antibodies. The toxoids significantly enhanced the IgG and IgM response against OMPs with a potency equivalent to CT, with the response being characterized by both IgG1 and IgG2a isotypes, and increased IFN-gamma production. Additionally, bactericidal activity was induced with IgG and IgM antibodies of high avidity. These results support the use of the new toxoids as potent inducing adjuvants that are particularly suitable for mucosal immunization.
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Affiliation(s)
- Tatiane Ferreira
- Immunology Department, Adolfo Lutz Institute, Avenue Dr. Arnaldo 355, 11 andar, 01246-902 São Paulo, SP, Brazil
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Menezes MA, Aires KA, Ozaki CY, Ruiz RM, Pereira MC, Abreu PA, Elias WP, Ramos OH, Piazza RM. Cloning approach and functional analysis of anti-intimin single-chain variable fragment (scFv). BMC Res Notes 2011; 4:30. [PMID: 21288327 PMCID: PMC3038928 DOI: 10.1186/1756-0500-4-30] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 02/02/2011] [Indexed: 01/28/2023] Open
Abstract
Background Intimin is an important virulence factor involved in the pathogenesis of enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic Escherichia coli (EHEC). Both pathogens are still important causes of diarrhea in children and adults in many developing and industrialized countries. Considering the fact that antibodies are important tools in the detection of various pathogens, an anti-intimin IgG2b monoclonal antibody was previously raised in immunized mice with the conserved sequence of the intimin molecule (int388-667). In immunoblotting assays, this monoclonal antibody showed excellent specificity. Despite good performance, the monoclonal antibody failed to detect some EPEC and EHEC isolates harboring variant amino acids within the 338-667 regions of intimin molecules. Consequently, motivated by its use for diagnosis purposes, in this study we aimed to the cloning and expression of the single-chain variable fragment from this monoclonal antibody (scFv). Findings Anti-intimin hybridoma mRNA was extracted and reversely transcripted to cDNA, and the light and heavy chains of the variable fragment of the antibody were amplified using commercial primers. The amplified chains were cloned into pGEM-T Easy vector. Specific primers were designed and used in an amplification and chain linkage strategy, obtaining the scFv, which in turn was cloned into pAE vector. E. coli BL21(DE3)pLys strain was transformed with pAE scFv-intimin plasmid and subjected to induction of protein expression. Anti-intimin scFv, expressed as inclusion bodies (insoluble fraction), was denatured, purified and submitted to refolding. The protein yield was 1 mg protein per 100 mL of bacterial culture. To test the functionality of the scFv, ELISA and immunofluorescence assays were performed, showing that 275 ng of scFv reacted with 2 mg of purified intimin, resulting in an absorbance of 0.75 at 492 nm. The immunofluorescence assay showed a strong reactivity with EPEC E2348/69. Conclusion This study demonstrated that the recombinant anti-intimin antibody obtained is able to recognize the conserved region of intimin (Int388-667) in purified form and the EPEC isolate.
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Affiliation(s)
- Márcio A Menezes
- Laboratório de Bacteriologia, Instituto Butantan, Avenida Vital Brazil, 1500, São Paulo, SP, 05503-900, Brazil.
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Bai S, Zhao J, Zhang Y, Huang W, Xu S, Chen H, Fan LM, Chen Y, Deng XW. Rapid and reliable detection of 11 food-borne pathogens using thin-film biosensor chips. Appl Microbiol Biotechnol 2010; 86:983-90. [PMID: 20091028 DOI: 10.1007/s00253-009-2417-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Revised: 12/16/2009] [Accepted: 12/17/2009] [Indexed: 01/10/2023]
Abstract
Traditional methods for identifying food-borne pathogens are time-consuming and laborious, so it is necessary to develop innovative methods for the rapid identification of food-borne pathogens. Here, we report the development of silicon-based optical thin-film biosensor chips for sensitive detection of 11 food-borne pathogens. Briefly, aldehyde-labeled probes were arrayed and covalently attached to a hydrazine-derivatized chip surface, and then, biotinylated polymerase chain reaction (PCR) amplicons were hybridized with the probes. After washing and brief incubation with an antibiotin immunoglobulin G-horseradish peroxidase conjugate and a precipitable horseradish peroxidase substrate, biotinylated chains bound to the probes were visualized as a color change on the chip surface (gold to blue/purple). Highly sensitive and accurate examination of PCR fragment targets can be completed within 30 min. This assay is extremely robust, sensitive, specific, and economical and can be adapted to different throughputs. Thus, a rapid, sensitive, and reliable technique for detecting 11 food-borne pathogens was successfully developed.
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Affiliation(s)
- Sulan Bai
- Key Laboratory of Genetics and Biotechnology, College of Life Sciences, Capital Normal University, Beijing, People's Republic of China
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12
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Abstract
Functional antibody assays can broadly be divided into three categories: neutralisation, serum bactericidal antibody (SBA) and opsonophagocytic assays (OPA). These biological assays are generally more complex than antibody-binding counterparts. They invariably involve multiple biological components, many of which are difficult or impossible to standardise. The aim of this chapter is to provide working examples of these assays and highlight the key issues to be addressed to ensure they are able to provide reliable data.
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Affiliation(s)
- Ian Feavers
- National Institute for Biological Standards and Controls, Potters Bar, Hertfordshire, UK
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Nara JM, Cianciarullo AM, Culler HF, Bueris V, Horton DSPQ, Menezes MA, Franzolin MR, Elias WP, Piazza RMF. Differentiation of typical and atypical enteropathogenic Escherichia coli using colony immunoblot for detection of bundle-forming pilus expression. J Appl Microbiol 2009; 109:35-43. [PMID: 19968733 DOI: 10.1111/j.1365-2672.2009.04625.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
AIMS The aim of study was to develop a colony immunoblot assay to differentiate typical from atypical enteropathogenic Escherichia coli (EPEC) by detection of bundle-forming pilus (BFP) expression. METHODS AND RESULTS Anti-BFP antiserum was raised in rabbits and its reactivity was confirmed by immunoelectron microscopy and by immunoblotting recognizing bundlin, the major pilus repeating subunit. The bacterial isolates tested in the colony immunoblot assay were grown in different media. Proteins from bacterial isolates were transferred to nitrocellulose membrane after treatment with phosphate buffer containing Triton X-100, EDTA and sodium chloride salts. When 24 typical EPEC and 96 isolates including, 72 atypical EPEC, 13 Gram-negative type IV-expressing strains and 11 enterobacteriaceae were cultivated in Dulbecco's Modified Eagle's Medium agar containing fetal bovine serum or in blood agar in the presence of CaCl(2) , they showed a positivity of 92 and 83%, and specificity of 96 and 97%, respectively. CONCLUSION The assay enables reliable identification of BFP-expressing isolates and contributes to the differentiation of typical and atypical EPEC. SIGNIFICANCE AND IMPACT OF THE STUDY The colony immunoblot for BFP detection developed in this study combines the simplicity of an immunoserological assay with the high efficiency of testing a large number of EPEC colonies.
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Affiliation(s)
- J M Nara
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
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14
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Menezes MA, Rocha LB, Koga PCM, Fernandes I, Nara JM, Magalhães CA, Abe CM, Ayala CO, Burgos YK, Elias WP, Castro AFP, Piazza RMF. Identification of enteropathogenic and enterohaemorrhagic Escherichia coli strains by immunoserological detection of intimin. J Appl Microbiol 2009; 108:878-887. [PMID: 19709337 DOI: 10.1111/j.1365-2672.2009.04484.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To evaluate the sensitivity and specificity of polyclonal and monoclonal antibodies (Mabs) against intimin in the detection of enteropathogenic and enterohaemorrhagic Escherichia coli isolates using immunoblotting. METHODS AND RESULTS Polyclonal and Mabs against the intimin-conserved region were raised, and their reactivities were compared in enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC) isolates using immunoblotting analysis. In comparison with rat antiserum, rabbit anti-intimin IgG-enriched fraction had a stronger recognition pattern to a wide spectrum of intimin types in different EPEC and EHEC serotypes. On the other hand, murine monoclonal IgG2b specific to intimin, with dissociation constant of 1.3x10(-8) mol l(-1), failed in the detection of some of these isolates. CONCLUSION All employed antibodies showed 100% specificity, not reacting with any of the eae-negative isolates. The sensitivity range was according to the employed antisera, and 97% for rabbit anti-intimin IgG-enriched fraction, followed by 92% and 78% sensitivity with rat antisera and Mab. SIGNIFICANCE AND IMPACT OF THE STUDY The rabbit anti-intimin IgG-enriched fraction in immunoblotting analysis is a useful tool for EPEC and EHEC diagnoses.
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Affiliation(s)
- M A Menezes
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - L B Rocha
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - P C M Koga
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - I Fernandes
- Laboratório de Imunopatologia, Instituto Butantan, São Paulo, SP, Brazil
| | - J M Nara
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - C A Magalhães
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - C M Abe
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - C O Ayala
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Y K Burgos
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - W P Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
| | - A F P Castro
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - R M F Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brazil
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