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Debnath A, Sabui S, Chatterjee NS. Structural and functional characterization of colonization factors AIBI-CS6 and AIIBII-CS6 of enterotoxigenic Escherichia coli. Protein Expr Purif 2023; 203:106201. [PMID: 36400365 DOI: 10.1016/j.pep.2022.106201] [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: 10/02/2022] [Revised: 10/30/2022] [Accepted: 11/10/2022] [Indexed: 11/17/2022]
Abstract
Over time, the structure and function of the broadly dispersed colonization factor (CF) CS6 of enterotoxigenic Escherichia coli (ETEC) have become more significant. CS6 is composed of tightly-associated subunits, CssA and CssB which due to presence of natural point mutation gave rise to CS6 subtypes. In contrast to the other ETEC CFs, CS6 is an afimbrial, spherical-shaped oligomers of (CssA-CssB)n complex where 'n' is concentration dependent. In this study, we have compared AIBI-CS6 and AIIBII-CS6 structurally and functionally. The Mw of CssAI was 18.5 kDa but Mw of CssAII was 15.1 kDa. Both CssBI and CssBII had Mw of 15.9 kDa. The substitution of Gly39 with Ala39 in CssAI leads to reduction in Mw from 18.5 to 15.1 kDa. Due to higher Mw of CssAI, the size of AIBI concentration-dependent oligomers should be higher. However, the Mw of AIIBII oligomers were higher and AIIBII also showed higher oligomeric forms compared to AIBI both in native PAGE and electron microscopy. The oligomers of both subtypes could withstand greater temperatures and denaturant concentrations. In terms of cellular response, the levels of inflammatory cytokines were significantly higher in case of AIBI-CS6 expressing ETEC as compared to AIIBII-CS6 expressing ETEC both in vitro and in vivo. When inflammatory cytokines were evaluated after infecting suckling mice with these ETEC strains, the results were consistent. In conclusion, even though there was subtle structural difference between AIBI-CS6 and AIIBII-CS6 due to natural point mutations but ETEC strains expressing these subtypes displayed great variability in pathogenicity.
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Affiliation(s)
- Anusuya Debnath
- Department of Biotechnology, Brainware University, Kolkata, India; National Institute of Cholera and Enteric Diseases, Kolkata, India.
| | - Subrata Sabui
- University of California-Irvine, VAMCLB-151, Long Beach, CA, 90822, USA; National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Nabendu Sekhar Chatterjee
- Division of Basic Medical Sciences at Indian Council of Medical Research (ICMR), New Delhi, India; National Institute of Cholera and Enteric Diseases, Kolkata, India
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Asmani F, Khavari-Nejad RA, Salmanian AH, Amani J. Immunological evaluation of recombinant chimeric construct from Enterotoxigenic E. coli expressed in hairy roots. Mol Immunol 2022; 147:81-89. [DOI: 10.1016/j.molimm.2022.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/26/2022] [Accepted: 02/09/2022] [Indexed: 01/05/2023]
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Moon J, Barry EM. Sequence variations in the ETEC CS6 operon affect transcript and protein expression. Virulence 2021; 12:2659-2669. [PMID: 34672874 PMCID: PMC8923064 DOI: 10.1080/21505594.2021.1981000] [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] [Indexed: 11/16/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrheal disease in developing nations where it accounts for a significant disease burden in children between the ages of 0 to 59 months. It is also the number one bacterial causative agent of traveler’s diarrhea. ETEC infects hosts through the fecal-oral route and utilizes colonization factors (CF) to adhere within the small intestine. Over 25 CFs have been identified; 7 are considered major CFs and a vaccine targeting these is predicted to provide protection against up to 66% of ETEC associated disease. Coli Surface Antigen 6 (CS6) is a major CF and is associated with disease-causing ETEC isolates. Analysis of the CS6 operon sequence led to the identification of two regions of variability among clinical isolates which we predicted exert effects on CS6 transcript and protein expression. A total of 7 recombinant E. coli strains were engineered to encode the CS6 operon in wild-type, hybrid, and mutant configurations. Western blot analysis and RT-qPCR provided evidence to support the importance of an intergenic hairpin structure on CS6 expression. Our results reveal the significance of CS6 sequence selection regarding ETEC vaccine development and present novel information regarding CS6 sequence variation in WT ETEC strains.
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Affiliation(s)
- Jonathan Moon
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Eileen M Barry
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA
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Talaat KR, Porter CK, Bourgeois AL, Lee TK, Duplessis CA, Maciel M, Gutierrez RL, DeNearing B, Adjoodani B, Adkinson R, Testa KJ, Feijoo B, Alcala AN, Brubaker J, Beselman A, Chakraborty S, Sack D, Halpern J, Trop S, Wu H, Jiao J, Sullivan E, Riddle MS, Joseph SS, Poole ST, Prouty MG. Oral delivery of Hyperimmune bovine serum antibodies against CS6-expressing enterotoxigenic Escherichia coli as a prophylactic against diarrhea. Gut Microbes 2020; 12:1732852. [PMID: 32167011 PMCID: PMC7524165 DOI: 10.1080/19490976.2020.1732852] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND . Oral administration of bovine antibodies active against enterotoxigenic Escherichia coli (ETEC) have demonstrated safety and efficacy against diarrhea in human challenge trials. The efficacy of bovine serum immunoglobulins (BSIgG) against recombinant colonization factor CS6 or whole cell ETEC strain B7A was assessed against challenge with the CS6-expressing B7A. METHODS . This was a randomized, double-blind, placebo-controlled trial in which healthy adults received oral hyperimmune BSIgG anti-CS6, anti-B7A whole cell killed or non-hyperimmune BSIgG (placebo) in a 1:1:1 ratio then challenged with ETEC B7A. Two days pre-challenge, volunteers began a thrice daily, seven day course of immunoprophylaxis. On day 3, subjects received 1 × 1010 CFUs of B7A. Subjects were observed for safety and the primary endpoint of moderate-severe diarrhea (MSD). RESULTS . A total of 59 volunteers received product and underwent ETEC challenge. The BSIgG products were well-tolerated across all subjects. Upon challenge, 14/20 (70%) placebo recipients developed MSD, compared to 12/19 (63%; p = .74) receiving anti-CS6 BSIgG and 7/20 (35%; p = .06) receiving anti-B7A BSIgG. Immune responses to the ETEC infection were modest across all groups. CONCLUSIONS . Bovine-derived serum antibodies appear safe and well tolerated. Antibodies derived from cattle immunized with whole cell B7A provided 50% protection against MSD following B7A challenge; however, no protection was observed in subjects receiving serum antibodies targeting CS6. The lack of observed efficacy in this group may be due to low CS6 surface expression on B7A, the high dose challenge inoculum and/or the use of serum derived antibodies versus colostrum-derived antibodies.
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Affiliation(s)
- KR Talaat
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - CK Porter
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, USA,CONTACT CK Porter Naval Medical Research Center, Silver Spring, MD, USA
| | - AL Bourgeois
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - TK Lee
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, USA
| | - CA Duplessis
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, USA
| | - M Maciel
- The Henry M. Jackson Foundation, Bethesda, MD, USA
| | - RL Gutierrez
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, USA
| | - B DeNearing
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - B Adjoodani
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - R Adkinson
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - KJ Testa
- The Henry M. Jackson Foundation, Bethesda, MD, USA
| | - B Feijoo
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - AN Alcala
- The Henry M. Jackson Foundation, Bethesda, MD, USA
| | - J Brubaker
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - A Beselman
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - S Chakraborty
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - D Sack
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - J Halpern
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - S Trop
- The Henry M. Jackson Foundation, Bethesda, MD, USA
| | - H Wu
- SAB Biotherapeutics Inc, Sioux Falls, SD, USA
| | - J Jiao
- SAB Biotherapeutics Inc, Sioux Falls, SD, USA
| | - E Sullivan
- SAB Biotherapeutics Inc, Sioux Falls, SD, USA
| | - MS Riddle
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, USA
| | - SS Joseph
- The Henry M. Jackson Foundation, Bethesda, MD, USA
| | - ST Poole
- The Henry M. Jackson Foundation, Bethesda, MD, USA
| | - MG Prouty
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, USA
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Govindarajan DK, Viswalingam N, Meganathan Y, Kandaswamy K. Adherence patterns of Escherichia coli in the intestine and its role in pathogenesis. MEDICINE IN MICROECOLOGY 2020. [DOI: 10.1016/j.medmic.2020.100025] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Biochemical and Immunological Evaluation of Recombinant CS6-Derived Subunit Enterotoxigenic Escherichia coli Vaccine Candidates. Infect Immun 2019; 87:IAI.00788-18. [PMID: 30602504 DOI: 10.1128/iai.00788-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 12/16/2018] [Indexed: 12/23/2022] Open
Abstract
CS6, a prevalent surface antigen expressed in nearly 20% of clinical enterotoxigenic Escherichia coli (ETEC) isolates, is comprised of two major subunit proteins, CssA and CssB. Using donor strand complementation, we constructed a panel of recombinant proteins of 1 to 3 subunits that contained combinations of CssA and/or CssB subunits and a donor strand, a C-terminal extension of 16 amino acids that was derived from the N terminus of either CssA or CssB. While the entire panel of recombinant proteins could be obtained as soluble, folded proteins, it was observed that the proteins possessing a heterologous donor strand, derived from the CS6 subunit different from the C-terminal subunit, had the highest degree of physical and thermal stability. Immunological characterization of the proteins, using a murine model, demonstrated that robust anti-CS6 immune responses were generated from fusions containing both CssA and CssB. Proteins containing only CssA were weakly immunogenic. Heterodimers, i.e., CssBA and CssAB, were sufficient to recapitulate the anti-CS6 immune response elicited by immunization with CS6, including the generation of functional neutralizing antibodies, as no further enhancement of the response was obtained with the addition of a third CS6 subunit. Our findings here demonstrate the feasibility of including a recombinant CS6 subunit protein in a subunit vaccine strategy against ETEC.
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Bhakat D, Debnath A, Naik R, Chowdhury G, Deb A, Mukhopadhyay A, Chatterjee N. Identification of common virulence factors present in enterotoxigenicEscherichia coliisolated from diarrhoeal patients in Kolkata, India. J Appl Microbiol 2018; 126:255-265. [DOI: 10.1111/jam.14090] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 07/17/2018] [Accepted: 08/23/2018] [Indexed: 12/25/2022]
Affiliation(s)
- D. Bhakat
- Division of Biochemistry; ICMR-National Institute of Cholera and Enteric Diseases; Kolkata India
| | - A. Debnath
- Division of Biochemistry; ICMR-National Institute of Cholera and Enteric Diseases; Kolkata India
| | - R. Naik
- Division of Biochemistry; ICMR-National Institute of Cholera and Enteric Diseases; Kolkata India
| | - G. Chowdhury
- Division of Bacteriology; ICMR-National Institute of Cholera and Enteric Diseases; Kolkata India
| | - A.K. Deb
- Division of Epidemiology; ICMR-National Institute of Cholera and Enteric Diseases; Kolkata India
| | - A.K. Mukhopadhyay
- Division of Bacteriology; ICMR-National Institute of Cholera and Enteric Diseases; Kolkata India
| | - N.S. Chatterjee
- Division of Biochemistry; ICMR-National Institute of Cholera and Enteric Diseases; Kolkata India
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8
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Ban E, Yoshida Y, Wakushima M, Wajima T, Hamabata T, Ichikawa N, Abe H, Horiguchi Y, Hara-Kudo Y, Kage-Nakadai E, Yamamoto T, Wada T, Nishikawa Y. Characterization of unstable pEntYN10 from enterotoxigenic Escherichia coli (ETEC) O169:H41. Virulence 2016; 6:735-44. [PMID: 26575107 DOI: 10.1080/21505594.2015.1094606] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) serotype O169:H41 has been an extremely destructive epidemic ETEC type worldwide. The strain harbors a large unstable plasmid that is regarded as responsible for its virulence, although its etiology has remained unknown. To examine its genetic background specifically on the unstable retention and responsibility in the unique adherence to epithelial cells and enterotoxin production, the complete sequence of a plasmid, pEntYN10, purified from the serotype strain was determined. The length is 145,082 bp; its GC content is 46.15%. It contains 182 CDSs, which include 3 colonization factors (CFs), an enterotoxin, and large number of insertion sequences. The repertory of plasmid stability genes was extraordinarily scant. Uniquely, results showed that 3 CFs, CS6, CS8 (CFA/III)-like, and K88 (F4)-like were encoded redundantly in the plasmid with unique variations among previously known subtypes. These three CFs preserved their respective gene structures similarly to those of other ETEC strains reported previously with unique sequence variations respectively. It is particularly interesting that the K88-like gene cluster of pEntYN10 had 2 paralogous copies of faeG, which encodes the major component of fimbrial structure. It remains to be verified how the unique variations found in the CFs respectively affect the affinity to infected cells, host range, and virulence of the ETEC strain.
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Affiliation(s)
- Erika Ban
- a Department of Food and Human Health Sciences ; Graduate School of Human Life Science; Osaka City University ; Osaka , Japan
| | - Yuka Yoshida
- a Department of Food and Human Health Sciences ; Graduate School of Human Life Science; Osaka City University ; Osaka , Japan
| | - Mitsuko Wakushima
- a Department of Food and Human Health Sciences ; Graduate School of Human Life Science; Osaka City University ; Osaka , Japan
| | - Takeaki Wajima
- b Department of Microbiology ; School of Pharmacy; Tokyo University of Pharmacy and Life Sciences ; Tokyo , Japan
| | - Takashi Hamabata
- c Research Institute; National Center for Global Health and Medicine ; Tokyo , Japan
| | - Naoki Ichikawa
- a Department of Food and Human Health Sciences ; Graduate School of Human Life Science; Osaka City University ; Osaka , Japan
| | - Hiroyuki Abe
- d Department of Molecular Bacteriology ; Research Institute for Microbial Diseases; Osaka University ; Osaka , Japan
| | - Yasuhiko Horiguchi
- d Department of Molecular Bacteriology ; Research Institute for Microbial Diseases; Osaka University ; Osaka , Japan
| | - Yukiko Hara-Kudo
- e Division of Microbiology; National Institute of Health Sciences ; Tokyo , Japan
| | - Eriko Kage-Nakadai
- f The OCU Advanced Research Institute for Natural Science and Technology; Osaka City University ; Osaka , Japan
| | - Taro Yamamoto
- g Department of International Health ; Institute of Tropical Medicine; Nagasaki University ; Nagasaki , Japan
| | - Takayuki Wada
- g Department of International Health ; Institute of Tropical Medicine; Nagasaki University ; Nagasaki , Japan
| | - Yoshikazu Nishikawa
- a Department of Food and Human Health Sciences ; Graduate School of Human Life Science; Osaka City University ; Osaka , Japan
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9
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Characterization of oligomeric assembly of colonization factor CS6 from enterotoxigenic Escherichia coli. Microbiology (Reading) 2016; 162:72-83. [DOI: 10.1099/mic.0.000180] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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10
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Debnath A, Wajima T, Sabui S, Hamabata T, Ramamurthy T, Chatterjee NS. Two specific amino acid variations in colonization factor CS6 subtypes of enterotoxigenic Escherichia coli results in differential binding and pathogenicity. MICROBIOLOGY-SGM 2015; 161:865-74. [PMID: 25635273 DOI: 10.1099/mic.0.000038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/16/2015] [Indexed: 11/18/2022]
Abstract
CS6 is the predominant colonization factor of enterotoxigenic Escherichia coli (ETEC). We report the existence of multiple CS6 subtypes caused by natural point mutations in cssA and cssB, the structural genes for CS6. The subtype AIBI was mostly associated with ETEC isolated from diarrhoeal cases, whereas AIIBII was mostly found in asymptomatic controls. Here we explore the rationale behind this association. ETEC isolates expressing AIIBII showed weaker adherence to intestinal epithelial cells compared with ETEC expressing AIBI. AIIBII expression on the ETEC cell surface was threefold less than AIBI. We found that alanine at position 37 in CssAII, in conjunction with asparagine at position 97 in CssBII, was responsible for the decreased levels of AIIBII on the bacterial surface. In addition, purified AIIBII showed fourfold less mucin binding compared with AIBI. The asparagine at position 97 in CssBII was also accountable for the decreased mucin binding by AIIBII. Reduced fluid accumulation and colonization occurred during infection with ETEC expressing AIIBII in animal models. Together these results indicate that the differential adherence between AIBI and AIIBII was a cumulative effect of decreased surface-level expression and mucin binding of AIIBII due to two specific amino acid variations. As a consequence, ETEC expressing these two subtypes displayed differential pathogenicity. We speculate that this might explain the subjective association of AIBI with ETEC from diarrhoeal cases and AIIBII with asymptomatic controls.
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Affiliation(s)
- Anusuya Debnath
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Takeaki Wajima
- National Centre for Global Health and Medicine, Tokyo, Japan
| | - Subrata Sabui
- National Institute of Cholera and Enteric Diseases, Kolkata, India
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11
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Identification of enterotoxigenic Escherichia coli (ETEC) clades with long-term global distribution. Nat Genet 2014; 46:1321-6. [PMID: 25383970 DOI: 10.1038/ng.3145] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 10/17/2014] [Indexed: 12/15/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC), a major cause of infectious diarrhea, produce heat-stable and/or heat-labile enterotoxins and at least 25 different colonization factors that target the intestinal mucosa. The genes encoding the enterotoxins and most of the colonization factors are located on plasmids found across diverse E. coli serogroups. Whole-genome sequencing of a representative collection of ETEC isolated between 1980 and 2011 identified globally distributed lineages characterized by distinct colonization factor and enterotoxin profiles. Contrary to current notions, these relatively recently emerged lineages might harbor chromosome and plasmid combinations that optimize fitness and transmissibility. These data have implications for understanding, tracking and possibly preventing ETEC disease.
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12
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Zeinalzadeh N, Salmanian AH, Ahangari G, Sadeghi M, Amani J, Bathaie SZ, Jafari M. Design and characterization of a chimeric multiepitope construct containing CfaB, heat-stable toxoid, CssA, CssB, and heat-labile toxin subunit B of enterotoxigenicEscherichia coli: a bioinformatic approach. Biotechnol Appl Biochem 2014; 61:517-27. [DOI: 10.1002/bab.1196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 12/19/2013] [Indexed: 12/24/2022]
Affiliation(s)
- Narges Zeinalzadeh
- Department of Medical Biotechnology; National Institute of Genetic Engineering and Biotechnology (NIGEB); Shahrak-e-Pajoohesh; Tehran Iran
| | | | - Ghasem Ahangari
- Department of Medical Biotechnology; NIGEB, Shahrak-e-Pajoohesh; Tehran Iran
| | - Mahdi Sadeghi
- Department of Basic Science; NIGEB, Shahrak-e-Pajoohesh; Tehran Iran
| | - Jafar Amani
- Applied Biotechnology Research Center; Baqiyatallah Medical Science University; Tehran Iran
| | - S. Zahra Bathaie
- Department of Clinical Biochemistry; Faculty of Medical Sciences; Tarbiat Modares University; Tehran Iran
| | - Mahyat Jafari
- Department of Medical Biotechnology; National Institute of Genetic Engineering and Biotechnology (NIGEB); Shahrak-e-Pajoohesh; Tehran Iran
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13
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Nazarian S, Gargari SLM, Rasooli I, Alerasol M, Bagheri S, Alipoor SD. Prevalent Phenotypic and Genotypic Profile of Enterotoxigenic Escherichia coli among Iranian Children. Jpn J Infect Dis 2014; 67:78-85. [DOI: 10.7883/yoken.67.78] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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14
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Wajima T, Sabui S, Kano S, Ramamurthy T, Chatterjee NS, Hamabata T. Entire sequence of the colonization factor coli surface antigen 6-encoding plasmid pCss165 from an enterotoxigenic Escherichia coli clinical isolate. Plasmid 2013; 70:343-52. [DOI: 10.1016/j.plasmid.2013.07.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 07/15/2013] [Accepted: 07/28/2013] [Indexed: 11/15/2022]
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15
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Croxen MA, Law RJ, Scholz R, Keeney KM, Wlodarska M, Finlay BB. Recent advances in understanding enteric pathogenic Escherichia coli. Clin Microbiol Rev 2013; 26:822-80. [PMID: 24092857 PMCID: PMC3811233 DOI: 10.1128/cmr.00022-13] [Citation(s) in RCA: 829] [Impact Index Per Article: 75.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli.
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Nazarian S, Gargari SLM, Rasooli I, Hasannia S, Pirooznia N. A PLGA-encapsulated chimeric protein protects against adherence and toxicity of enterotoxigenic Escherichia coli. Microbiol Res 2013; 169:205-12. [PMID: 23906742 DOI: 10.1016/j.micres.2013.06.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/20/2013] [Accepted: 06/14/2013] [Indexed: 01/14/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) are the most common cause of diarrhea among children. Colonization factors and enterotoxins are the major ETEC candidate vaccines. Since protection against ETEC mostly occurs by induction of IgA antibodies, much effort is focused on the development of oral vaccines. In this study oral immunogenicity of a poly(lactic-co-glycolic acid) (PLGA) encapsulated chimeric protein containing CfaB, CstH, CotA and LTB (Heat-labile B subunit) was investigated. The protein was encapsulated in PLGA by double emulsion method and nanoparticles were characterized physicochemically. Immunogenicity was assessed by evaluating IgG1, IgG2 and IgA titers after BALB/c mice vaccination. Non aggregated nanoparticles had a spherical shape with an average particle size of 252.7±23 nm and 91.96±4.4% of encapsulation efficiency. Western blotting showed maintenance of the molecular weight and antigenicity of the released protein. Oral immunization of mice induced serum IgG and fecal IgA antibody responses. Immunization induced protection against ETEC binding to Caco-2 cells. The effect of LT toxin on fluid accumulation in ileal loops was neutralized by inhibition of enterotoxin binding to GM1-ganglosides. Delivery of the chimeric protein in PLGA elicited both systemic and mucosal immune responses. The findings could be exploited to development of oral multi-component ETEC prophylactic measures.
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Affiliation(s)
| | | | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran
| | - Sadegh Hasannia
- Tarbiat Modares University, Faculty of Biological Sciences, Tehran, Iran
| | - Nazanin Pirooznia
- Faculty of Science, Department of Biology, University of Guilan, Rasht, Iran
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17
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Nada RA, Armstrong A, Shaheen HI, Nakhla I, Sanders JW, Riddle MS, Young S, Sebeny P. Phenotypic and genotypic characterization of enterotoxigenic Escherichia coli isolated from U.S. military personnel participating in Operation Bright Star, Egypt, from 2005 to 2009. Diagn Microbiol Infect Dis 2013; 76:272-7. [PMID: 23639795 DOI: 10.1016/j.diagmicrobio.2013.03.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 03/06/2013] [Accepted: 03/22/2013] [Indexed: 11/16/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major health problem for travelers to the Middle East. During the autumn months of 2005, 2007, and 2009, U.S. military personnel participated in Operation Bright Star (OBS) exercises in Egypt. Out of 181 military personnel enrolled in a diarrheal surveillance study, E. coli-like colonies were isolated from 170 patients. Isolates were tested for the detection of ETEC enterotoxins and colonization factors (CFs) using phenotypic and genotypic methods. Additionally, we studied the secular trends of ETEC isolates obtained from OBS studies since 1999. ETEC was isolated from 51.2% and 60.0% of the patients based on enzyme-linked immunosorbent assay and polymerase chain reaction (PCR), respectively. Heat stable (ST) was the dominant enterotoxin detected followed by heat labile (LT) and LTST. Additionally, we detected a CF in 59.7% and 67.6% of the ETEC-positive isolates using dot blot and PCR assays, respectively. The predominant CF isolated was CS6 followed by CS3.
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Affiliation(s)
- Rania A Nada
- U.S. Naval Medical Research Unit No. 3, Cairo, Egypt.
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Real-time PCR-based mismatch amplification mutation assay for specific detection of CS6-expressing allelic variants of enterotoxigenic Escherichia coli and its application in assessing diarrheal cases and asymptomatic controls. J Clin Microbiol 2012; 50:1308-12. [PMID: 22219305 DOI: 10.1128/jcm.05424-11] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) expressing the colonization factor CS6 is widespread in many developing countries, including India. The different allelic variants of CS6, caused by point mutations in its structural genes, cssA and cssB, are designated AIBI, AIIBII, AIIIBI, AIBII, and AIIIBII. A simple, reliable, and specific mismatch amplification mutation assay based on real-time quantitative PCR (MAMA-qPCR) was developed for the first time for the detection of CS6-expressing ETEC, along with the identification of allelic variations. The assay was based on mismatched nucleotide incorporation at the penultimate base at the 3' ends of the reverse primers specific for cssA and cssB and was validated using 38 CS6-expressing ETEC isolates. This strategy was effective in detecting all the alleles containing single-nucleotide polymorphisms. Using MAMA-qPCR, we also tested CS6 allelic variants in 145 ETEC isolates from children with acute diarrhea and asymptomatic infections, with the latter serving as controls. We observed that the AIBI and AIIIBI allelic variants were mostly associated with cases rather than controls, whereas the AIIBII variants were detected mostly in controls. In addition, the AIBI and AIIIBI alleles were frequently associated with ETEC harboring the heat-stable toxin gene (est) alone or with the heat-labile toxin gene (elt), whereas the AIIBII allele was predominant in ETEC isolates harboring the elt gene. This study may help in understanding the association of allelic variants in CS6-expressing ETEC with the clinical features of diarrhea, as well as in ETEC vaccine studies.
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Enterotoxigenic Escherichia coli CS6 gene products and their roles in CS6 structural protein assembly and cellular adherence. Microb Pathog 2011; 51:243-9. [PMID: 21729748 DOI: 10.1016/j.micpath.2011.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 06/08/2011] [Accepted: 06/17/2011] [Indexed: 11/21/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) produces a variety of colonization factors necessary for attachment to the host cell, among which CS6 is one of the most prevalent in ETEC isolates from developing countries. The CS6 operon is composed of 4 genes, cssA, cssB, cssC, and cssD. The molecular mechanism of CS6 assembly and cell surface presentation, and the contribution of each protein to the attachment of the bacterium to intestinal cells remain unclear. In the present study, a series of css gene-deletion mutants of the CS6 operon were constructed in the ETEC genetic background, and their effect on adhesion to host cells and CS6 assembly was studied. Each subunit deletion resulted in a reduction in the adhesion to intestinal cells to the same level of laboratory E. coli strains, and this effect was restored by complementary plasmids, suggesting that the 4 proteins are necessary for CS6 expression. Bacterial cell fractionation and western blotting of the mutant strains suggested that the formation of a CssA-CssB-CssC complex is necessary for recognition by CssD and transport of CssA-CssB to the outer membrane as a colonization factor.
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