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Haugan I, Husby MG, Skjøtskift B, Aamnes Mostue D, Brun A, Olsen LC, Simpson MR, Lange H, Afset JE. Enteroaggregative Escherichia coli in mid-Norway: A prospective, case control study. PLoS One 2024; 19:e0301625. [PMID: 38635516 PMCID: PMC11025732 DOI: 10.1371/journal.pone.0301625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 03/19/2024] [Indexed: 04/20/2024] Open
Abstract
BACKGROUND The use of molecular methods has led to increased detection of Enteroaggregative Escherichia coli (EAEC) in faecal samples. Studies have yielded conflicting results regarding the clinical relevance of this finding. The objective of this study was to investigate the prevalence of EAEC in faecal samples from patients with diarrhoea and healthy controls and describe characteristics of EAEC positive persons. METHODS From March 1st, 2017 to February 28th, 2019, we investigated all consecutive faecal samples from patients with diarrhoea received at the laboratory and collected faecal samples from randomly invited healthy controls from mid-Norway. Real-time multiplex PCR was used for detection of bacterial, viral, and parasitic pathogens. We registered sex, age, urban versus non-urban residency, and travel history for all participants. Statistical analyses were performed with Pearson chi-squared test, Kruskal-Wallis test, and Mann-Whitney U test. RESULTS We identified EAEC in 440 of 9487 (4.6%) patients with diarrhoea and 8 of 375 (2.2%) healthy controls. The EAEC prevalence was 19.1% among those with diarrhoea and recent foreign travel and 2.2% in those without travel history independent of diarrhoea. Concomitant pathogens were detected in 64.3% of EAEC-positive patients with diarrhoea. The median age was 28.5 in those with EAEC-positive diarrhoea and 38 in those with EAEC-negative diarrhoea (p <0.01). In patients with diarrhoea, travel was reported in 72% of those with EAEC and concomitant pathogens, and 54% and 12% in those with only EAEC and no EAEC, respectively (p <0.01). CONCLUSIONS EAEC was a common detection, particularly in patients with diarrhoea and recent international travel, and was found together with other intestinal pathogens in the majority of cases. Our results suggest that domestically acquired EAEC is not associated with diarrhoea. Patients with EAEC-positive diarrhoea and concomitant pathogens were young and often reported recent travel history compared to other patients with diarrhoea.
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Affiliation(s)
- Ingvild Haugan
- Department of Medical Microbiology, Clinic of Laboratory Medicine, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Marit Gudrun Husby
- Department of Medical Microbiology, Clinic of Laboratory Medicine, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Bjørg Skjøtskift
- Department of Medical Microbiology, Clinic of Laboratory Medicine, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Dorothea Aamnes Mostue
- Department of Medical Microbiology, Clinic of Laboratory Medicine, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Andreas Brun
- Department of Medical Microbiology, Clinic of Laboratory Medicine, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Lene Christin Olsen
- Department of Medical Microbiology, Clinic of Laboratory Medicine, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Melanie Rae Simpson
- Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
- Clinical Research Unit Central Norway, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Heidi Lange
- Norwegian Institute of Public Health, Oslo, Norway
| | - Jan Egil Afset
- Department of Medical Microbiology, Clinic of Laboratory Medicine, St Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
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Zhang C, Li S, Upadhyay I, Lauder KL, Sack DA, Zhang W. MecVax supplemented with CFA MEFA-II induces functional antibodies against 12 adhesins (CFA/I, CS1-CS7, CS12, CS14, CS17, and CS21) and 2 toxins (STa, LT) of enterotoxigenic Escherichia coli (ETEC). Microbiol Spectr 2024; 12:e0415323. [PMID: 38364078 PMCID: PMC10986561 DOI: 10.1128/spectrum.04153-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/24/2024] [Indexed: 02/18/2024] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains that produce various adhesins and one or two enterotoxins are the leading causes of children's diarrhea and travelers' diarrhea. MecVax, a multivalent ETEC vaccine candidate, consists of two proteins, an adhesin multiepitope fusion antigen (MEFA) that stimulates antibodies to the seven most important ETEC adhesins (CFA/I and CS1-CS6) and a toxoid fusion antigen which stimulates antibodies against ETEC enterotoxins (heat-labile toxin and heat-stable toxin). CFA MEFA-II, another polyvalent MEFA protein, has been demonstrated to stimulate antibodies to another five important ETEC adhesins (CS7, CS12, CS14, CS17, and CS21). We hypothesize that MecVax coverage and efficacy can be expanded if MecVax could stimulate antibodies to all 12 adhesins. In this study, we supplemented MecVax with CFA MEFA-II, examined broad immunity to the 12 targeted ETEC adhesins and 2 ETEC toxins (STa, LT) in mice, and assessed mouse antibody functions for inhibiting the adherence of the 12 adhesins and neutralizing the enterotoxicity of 2 toxins, thus assessing the potential application of a broadly protective pan-ETEC vaccine. Mice intramuscularly immunized with MecVax and CFA MEFA-II developed robust antibody responses to the 12 ETEC adhesins and 2 toxins; furthermore, mouse serum antibodies showed functional activities against the adherence from each of the targeted adhesins and the enterotoxicity of either toxin. Data also indicated that CFA MEFA-II was antigenically compatible with MecVax. These results demonstrated that the inclusion of CFA MEFA-II further expands MecVax broad immunogenicity and protection coverage, suggesting the feasibility of developing a vaccine against all important diarrheal ETEC strains.IMPORTANCEThere are no vaccines licensed for Enterotoxigenic Escherichia coli (ETEC), a leading cause of children's diarrhea and the most common cause of travelers' diarrhea. Since ETEC strains produce over 25 adhesins and 2 distinctive enterotoxins, heterogeneity is a key obstacle to vaccine development. MecVax, a multivalent ETEC vaccine candidate, induces protective antibodies against the seven most important adhesins (CFA/I and CS1-CS6) associated with two-thirds of ETEC clinical cases. However, ETEC prevalence shifts chronically and geographically, and other adhesins are also associated with clinical cases. MecVax would become a pan-ETEC vaccine if it also protects against the remaining important adhesins. This study demonstrated that MecVax supplemented with adhesin protein CFA MEFA-II induces functional antibodies against 12 important ETEC adhesins (CFA/I, CS1-CS7, CS12, CS14, CS17, and CS21), enabling the development of a more broadly protective ETEC vaccine and further validating the application of the MEFA vaccinology platform for multivalent vaccine development.
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Affiliation(s)
- Chongyang Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Siqi Li
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Ipshita Upadhyay
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kathyrn L. Lauder
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - David A. Sack
- Department of International Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Weiping Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Terefe L, Nardos A, Debella A, Dereje B, Arega M, Abebe AG, Gemechu W, Woldekidan S. Antidiarrheal Activities of the Methanol Leaf Extracts of Olinia rochetiana (Oliniaceae) Against Castor Oil-Induced Diarrhea in Mice. J Exp Pharmacol 2023; 15:485-495. [PMID: 38026232 PMCID: PMC10676088 DOI: 10.2147/jep.s441555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 11/17/2023] [Indexed: 12/01/2023] Open
Abstract
Background Olinia rochetiana has been used traditionally to cure diarrheal disease. Therefore, this study aimed to investigate the acute toxicity and antidiarrheal effect of O. rochetiana leaf extracts. Methods Cold maceration was used to extract plant leaf powder with 80% methanol. The extract's antidiarrheal action was tested against a castor oil-induced diarrheal model, a charcoal meal test, and enteropooling tests at doses of 100, 200, and 400 mg/kg. Negative controls received the vehicle at 10 mL/kg, while positive controls received loperamide at 3 mg/kg. Results From the study, no apparent toxicity was observed when a single dose of 2000 mg/kg was administered. In the castor oil-induced model, the extract delayed the onset of diarrhea, reduced stool frequency, and decreased wet feces weight and number in a dose-dependent manner at 200 mg/kg (p < 0.05) and 400 mg/kg (p < 0.01). The percent reduction in moist feces at 100, 200, and 400 mg/kg was 54.2, 23.97, and 18.26%, respectively, indicating a significant dose-dependent decrease. In a charcoal meal test, the extracts at 200 and 400 mg/kg revealed a peristaltic index of 65 and 46%, respectively, with considerable inhibition of charcoal transport at 23 and 39%. The weight and volume of intestinal contents dropped significantly at a dose of 400 mg/kg (p < 0.01), which is 0.43 mg/kg, in the enteropooling test when compared with the tested dose. The computed in vivo antidiarrheal index revealed diarrheal inhibition values of 46.06 and 71.06% at 200 and 400 mg/kg, respectively. Conclusion In the current investigation, O. rochetiana showed significant antidiarrheal activity with no symptoms of toxicity in mice.
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Affiliation(s)
- Lidet Terefe
- Department of Pharmacology, School of Pharmacy, College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia
| | - Aschalew Nardos
- Department of Pharmacology, School of Pharmacy, College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia
| | - Asfaw Debella
- Department of Traditional and Modern Medicine Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Beyene Dereje
- Department of Pharmacology, School of Medicine, College of Medicine and Health Sciences, Dire Dawa University, Dire Dawa, Ethiopia
| | - Melese Arega
- Department of Pharmacy, Pawi Health Sciences College, Pawi, Ethiopia
| | - Abiy Gelagle Abebe
- Department of Traditional and Modern Medicine Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Worku Gemechu
- Department of Traditional and Modern Medicine Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
| | - Samuel Woldekidan
- Department of Traditional and Modern Medicine Research Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia
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Gore R, Mohsenipour M, Wood JL, Balasuriya GK, Hill-Yardin EL, Franks AE. Hyperimmune bovine colostrum containing lipopolysaccharide antibodies (IMM124-E) has a nondetrimental effect on gut microbial communities in unchallenged mice. Infect Immun 2023; 91:e0009723. [PMID: 37830823 PMCID: PMC10652967 DOI: 10.1128/iai.00097-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 08/21/2023] [Indexed: 10/14/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of bacterial diarrhea with the potential to cause long-term gastrointestinal (GI) dysfunction. Preventative treatments for ETEC-induced diarrhea exist, yet the effects of these treatments on GI commensals in healthy individuals are unclear. Whether administration of a prophylactic preventative treatment for ETEC-induced diarrhea causes specific shifts in gut microbial populations in controlled environments is also unknown. Here, we studied the effects of a hyperimmune bovine colostrum (IMM-124E) used in the manufacture of Travelan (AUST L 106709) on GI bacteria in healthy C57BL/6 mice. Using next-generation sequencing, we aimed to test the onset and magnitude of potential changes to the mouse gut microbiome in response to the antidiarrheagenic hyperimmune bovine colostrum product, rich in immunoglobulins against select ETEC strains (Travelan, Immuron Ltd). We show that in mice administered colostrum containing lipopolysaccharide (LPS) antibodies, there was an increased abundance of potentially gut-beneficial bacteria, such as Akkermansia and Desulfovibrio, without disrupting the underlying ecology of the GI tract. Compared to controls, there was no difference in overall weight gain, body or cecal weights, or small intestine length following LPS antibody colostrum supplementation. Overall, dietary supplementation with colostrum containing LPS antibodies produced subtle alterations in the gut bacterial composition of mice. Primarily, Travelan LPS antibody treatment decreased the ratio of Firmicutes/Bacteroidetes in gut microbial populations in unchallenged healthy mice. Further studies are required to examine the effect of Travelan LPS antibody treatment to engineer the microbiome in a diseased state and during recovery.
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Affiliation(s)
- Rachele Gore
- Neurodevelopment in Health and Disease Research Program, School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, Bundoora, Victoria, Australia
| | - Mitra Mohsenipour
- Neurodevelopment in Health and Disease Research Program, School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Jennifer L. Wood
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, Bundoora, Victoria, Australia
| | - Gayathri K. Balasuriya
- Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
| | - Elisa L. Hill-Yardin
- Neurodevelopment in Health and Disease Research Program, School of Health and Biomedical Sciences, RMIT University, Bundoora, Victoria, Australia
| | - Ashley E. Franks
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, Bundoora, Victoria, Australia
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Upadhyay I, Parvej SMD, Shen Y, Li S, Lauder KL, Zhang C, Zhang W. Protein-based vaccine candidate MecVax broadly protects against enterotoxigenic Escherichia coli intestinal colonization in a rabbit model. Infect Immun 2023; 91:e0027223. [PMID: 37874163 PMCID: PMC10652908 DOI: 10.1128/iai.00272-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/20/2023] [Indexed: 10/25/2023] Open
Abstract
There are no vaccines licensed against enterotoxigenic Escherichia coli (ETEC), a leading cause of children's diarrhea and the most common cause of travelers' diarrhea. Multivalent vaccine candidate MecVax unprecedentedly targets two ETEC enterotoxins (heat-stable toxin, STa; heat-labile toxin, LT) and the seven most prevalent ETEC adhesins (colonization factor antigen, CFA/I, coli surface antigens, CS1-CS6) and has been demonstrated preclinically to protect against STa- and LT-mediated ETEC clinical diarrhea and prevent intestinal colonization from ETEC strain H10407 (CFA/I, STa, LT). However, it is unattested whether MecVax broadly protects against intestinal colonization from ETEC strains producing the other six adhesins (CS1-CS6) also targeted by this product. In this study, we immunized rabbits with MecVax and challenged them with heterogeneous ETEC strains that express CS1-CS6 adhesins to evaluate MecVax's efficacy against bacterial intestinal colonization, thus providing broad vaccine protection against ETEC infection. Data revealed that rabbits intramuscularly immunized with MecVax developed robust responses to both ETEC enterotoxins (STa, LT) and seven adhesins (CFA/I, CS1-CS6), and when challenged with ETEC isolates expressing CS1/CS3, CS2/CS3, CS4/CS6, CS5/CS6, or CS6 adhesin, the immunized rabbits prevented over two logs (>99%) of bacteria from colonization in small intestines. Additionally, compared to a CFA-toxoid fusion protein, which is another potential ETEC vaccine antigen to target two ETEC enterotoxins and the seven adhesins, MecVax exhibited better protection against ETEC intestinal colonization. These results, in conjunction with the protection data from early studies, evidenced that MecVax is broadly protective, validating MecVax's candidacy as an effective vaccine against ETEC-associated diarrhea and accelerating ETEC vaccine development.
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Affiliation(s)
- Ipshita Upadhyay
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Shafiullah M. D. Parvej
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yiyang Shen
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Siqi Li
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kathryn L. Lauder
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Chongyang Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Weiping Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Svennerholm AM, Lundgren A. Developments in oral enterotoxigenic Escherichia coli vaccines. Curr Opin Immunol 2023; 84:102372. [PMID: 37523966 DOI: 10.1016/j.coi.2023.102372] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/11/2023] [Accepted: 07/04/2023] [Indexed: 08/02/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrhea in children in developing countries and in travelers. WHO has affirmed ETEC as a priority vaccine target, but there is no licensed ETEC vaccine available yet. We here describe recent, promising developments of different live, inactivated, and subunit ETEC candidate vaccines expressing or containing nontoxic enterotoxin and/or colonization factor antigens with a focus on oral vaccines. Many of the ETEC candidate vaccines have been tested in clinical trials for safety and immunogenicity and some of them also for protective efficacy in field trials or in challenge studies.
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Affiliation(s)
- Ann-Mari Svennerholm
- Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden.
| | - Anna Lundgren
- Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden
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Li S, Seo H, Upadhyay I, Zhang W. A Polyvalent Adhesin-Toxoid Multiepitope-Fusion-Antigen-Induced Functional Antibodies against Five Enterotoxigenic Escherichia coli Adhesins (CS7, CS12, CS14, CS17, and CS21) but Not Enterotoxins (LT and STa). Microorganisms 2023; 11:2473. [PMID: 37894131 PMCID: PMC10608864 DOI: 10.3390/microorganisms11102473] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
The increasing prevalence and association with moderate-to-severe diarrhea make enterotoxigenic Escherichia coli (ETEC) adhesins CS7, CS12, CS14, CS17, and CS21 potential targets of ETEC vaccines. Currently, there are no vaccines licensed to protect against ETEC, a top cause of children's diarrhea and travelers' diarrhea. Recently, a polyvalent adhesin protein (adhesin MEFA-II) was demonstrated to induce antibodies that inhibited adherence from these five ETEC adhesins and reduced the enterotoxicity of ETEC heat-stable toxin (STa), which plays a key role in causing ETEC-associated diarrhea. To improve adhesin MEFA-II for functional antibodies against STa toxin and the other ETEC toxin, heat-labile toxin (LT), we modified adhesin MEFA-II by adding another STa toxoid and an LT epitope; we examined the new antigen immunogenicity (to five adhesins and two toxins) and more importantly antibody functions against ETEC adherence and STa and LT enterotoxicity. Data show that mice intramuscularly immunized with the new antigen (adhesin MEFA-IIb) developed robust IgG responses to the targeted adhesins (CS7, CS12, CS14, CS17, and CS21) and toxins (STa and LT). Mouse antibodies inhibited the adherence of ETEC strains expressing any of these five adhesins but failed to neutralize STa or LT enterotoxicity. In further studies, rabbits intramuscularly immunized with adhesin MEFA-IIb developed robust antigen-specific antibodies; when challenged with an ETEC isolate expressing CS21 adhesin (JF2101, CS21, and STa), the immunized rabbits showed a significant reduction in intestinal colonization by ETEC bacteria. These data indicate that adhesin MEFA-IIb is broadly immunogenic and induces functional antibodies against the targeted ETEC adhesins but not the toxins.
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Affiliation(s)
| | | | | | - Weiping Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
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Brønstad I, von Volkmann HL, Sakkestad ST, Steinsland H, Hanevik K. Reduced Plasma Guanylin Levels Following Enterotoxigenic Escherichia coli-Induced Diarrhea. Microorganisms 2023; 11:1997. [PMID: 37630557 PMCID: PMC10458898 DOI: 10.3390/microorganisms11081997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/20/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
The intestinal peptide hormones guanylin (GN) and uroguanylin (UGN) interact with the epithelial cell receptor guanylate cyclase C to regulate fluid homeostasis. Some enterotoxigenic Escherichia coli (ETEC) produce heat-stable enterotoxin (ST), which induces diarrhea by mimicking GN and UGN. Plasma concentrations of prohormones of GN (proGN) and UGN (proUGN) are reportedly decreased during chronic diarrheal diseases. Here we investigate whether prohormone concentrations also drop during acute diarrhea caused by ST-producing ETEC strains TW10722 and TW11681. Twenty-one volunteers were experimentally infected with ETEC. Blood (n = 21) and urine (n = 9) specimens were obtained immediately before and 1, 2, 3, and 7 days after ETEC ingestion. Concentrations of proGN and proUGN were measured by ELISA. Urine electrolyte concentrations were measured by photometry and mass spectrometry. Ten volunteers developed diarrhea (D group), and eleven did not (ND group). In the D group, plasma proGN, but not proUGN, concentrations were substantially reduced on days 2 and 3, coinciding with one day after diarrhea onset. No changes were seen in the ND group. ETEC diarrhea also seemed to affect diuresis, the zinc/creatinine ratio, and sodium and chloride secretion levels in urine. ETEC-induced diarrhea causes a reduction in plasma proGN and could potentially be a useful marker for intestinal isotonic fluid loss.
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Affiliation(s)
- Ingeborg Brønstad
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, 5021 Bergen, Norway; (I.B.); (H.L.v.V.)
- Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
| | - Hilde Løland von Volkmann
- National Centre for Ultrasound in Gastroenterology, Haukeland University Hospital, 5021 Bergen, Norway; (I.B.); (H.L.v.V.)
- Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
| | - Sunniva Todnem Sakkestad
- Department of Clinical Science, University of Bergen, 5021 Bergen, Norway;
- National Center for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
| | - Hans Steinsland
- Centre for Intervention Science in Maternal and Child Health (CISMAC), Centre of International Health, Department of Global Public Health and Primary Care, University of Bergen, 5020 Bergen, Norway;
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway
| | - Kurt Hanevik
- Department of Clinical Science, University of Bergen, 5021 Bergen, Norway;
- National Center for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
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Upadhyay I, Parvej SMD, Li S, Lauder KL, Shen Y, Zhang W. Polyvalent Protein Adhesin MEFA-II Induces Functional Antibodies against Enterotoxigenic Escherichia coli (ETEC) Adhesins CS7, CS12, CS14, CS17, and CS21 and Heat-Stable Toxin (STa). Appl Environ Microbiol 2023; 89:e0068323. [PMID: 37212687 PMCID: PMC10304760 DOI: 10.1128/aem.00683-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 05/01/2023] [Indexed: 05/23/2023] Open
Abstract
There are no licensed vaccines for enterotoxigenic Escherichia coli (ETEC), a common cause of children's diarrhea and travelers' diarrhea. ETEC strains producing enterotoxins (heat-labile toxin, LT; heat-stable toxin, STa) and adhesins CFA/I, CFA/II (CS1-CS3) or CFA/IV (CS4-CS6) attributed to a majority of ETEC-associated diarrheal cases, thus the two toxins (STa, LT) and the seven adhesins (CFA/I, CS1 to CS6) are historically the primary targets in ETEC vaccine development. Recent studies, however, revealed that ETEC strains with adhesins CS14, CS21, CS7, CS17, and CS12 are also prevalent and cause moderate-to-severe diarrhea; these adhesins are now considered antigen targets as well for ETEC vaccines. In this study, we applied the epitope- and structure-based multiepitope-fusion-antigen (MEFA) vaccinology platform and constructed a polyvalent protein to present immuno-dominant continuous B-cell epitopes of these five adhesins (also an STa toxoid); we then characterized this protein antigen's (termed as adhesin MEFA-II) broad immunogenicity and evaluated antibody functions against each targeted adhesin and STa toxin. Data showed that mice intramuscularly immunized with adhesin MEFA-II protein developed robust IgG to the targeted adhesins and toxin STa. Importantly, the antigen-derived antibodies significantly inhibited adherence of ETEC bacteria expressing adhesin CS7, CS12, CS14, CS17, or CS21 and reduced STa enterotoxicity. These results indicated that adhesin MEFA-II protein is broadly immunogenic and induces cross-functional antibodies, suggesting adhesin MEFA-II can be an effective ETEC vaccine antigen; if included in an ETEC vaccine candidate, adhesin MEFA-II can expand vaccine coverage and increase efficacy against ETEC-associated children's diarrhea and travelers' diarrhea. IMPORTANCE An effective vaccine is lacking against ETEC, a primary cause of children's diarrhea and traveler's diarrhea and a threat to global health. The key challenge in ETEC vaccine development is that ETEC bacteria express heterogeneous virulence determinants (>25 adhesins and two toxins). While the current strategy to target the seven most prevalent ETEC adhesins (CFA/I, CS1 to CS6) potentially lead to a vaccine against many clinical cases, the prevalence of ETEC strains shifts chronically and geographically, and ETEC expressing other adhesins, mainly CS7, CS12, CS14, CS17, and CS21, also cause moderate-to-severe diarrhea. However, it is impossible to develop an ETEC vaccine to target as many as 12 adhesins under conventional approaches. This study used a unique vaccinology platform to create a polyvalent antigen and demonstrated the antigen's broad immunogenicity and functions against the targeted ETEC adhesins, enabling the development of a broadly protective vaccine essentially against all of the important ETEC strains.
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Affiliation(s)
- Ipshita Upadhyay
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Shafiullah M. D. Parvej
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Siqi Li
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kathryn L. Lauder
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yiyang Shen
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Weiping Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Strong Association between Diarrhea and Concentration of Enterotoxigenic Escherichia coli Strain TW10722 in Stools of Experimentally Infected Volunteers. Pathogens 2023; 12:pathogens12020283. [PMID: 36839555 PMCID: PMC9960819 DOI: 10.3390/pathogens12020283] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/27/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of diarrheal illness in children and travelers in low- and middle-income countries. When volunteers are infected with ETEC strains, as part of experimental infection studies, some do not develop diarrhea. To improve our understanding of how these volunteers are protected, we investigated the association between stool ETEC DNA concentration, as determined by quantitative PCR, and the development and severity of disease in 21 volunteers who had been experimentally infected with ETEC strain TW10722. We found a strong association between maximum stool ETEC DNA concentration and the development of diarrhea: all of the 11 volunteers who did not develop diarrhea had <0.99% TW10722-specific DNA in their stools throughout the follow-up period of up to 9 days, while all of the 10 volunteers who did develop diarrhea had maximum DNA concentrations of ≥0.99%. Most likely, these maximum stool TW10722 DNA concentrations reflect the level of intestinal colonization and the risk of experiencing diarrhea, thereby, seems to be directly dependent on the level of colonization. Thus, the development and availability of vaccines and other prophylactic measures, even if they only partially reduce colonization, could be important in the effort to reduce the burden of ETEC diarrhea.
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11
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Dual-Use Vaccine for Diarrhoeal Diseases: Cross-Protective Immunogenicity of a Cold-Chain-Free, Live-Attenuated, Oral Cholera Vaccine against Enterotoxigenic Escherichia coli (ETEC) Challenge in BALB/c Mice. Vaccines (Basel) 2022; 10:vaccines10122161. [PMID: 36560571 PMCID: PMC9787504 DOI: 10.3390/vaccines10122161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
In low- and middle-income countries, diarrhoeal diseases are the second most common cause of mortality in children, mainly caused by enterotoxin-producing bacteria, such as Shigella, Vibrio, Salmonella, and Escherichia coli. Cholera and traveller's diarrhoea are caused by Vibrio cholerae (O1 and O139 serogroups) and enterotoxigenic Escherichia coli (ETEC), respectively. The cholera toxin (CT) produced by V. cholerae and the heat-labile enterotoxin (LT) of ETEC are closely related by structure, function, and the immunological response to them. There is no exclusive vaccine for ETEC; however, cholera vaccines based on the CT-B component elicit a short-term cross-protection against ETEC infection. In this context, the cross-protective efficacy of MyCholTM, a prototype cold-chain-free, live-attenuated, oral cholera vaccine against V. cholerae O139 was evaluated in BALB/c mice. The 100% lethal dose (LD100) of 109 CFU/mL of the ETEC H10407 strain was used for the challenge studies. The mice immunised with MyChol™ survived the challenge by producing anti-CT antibodies, which cross-neutralised the LT toxin with no body weight loss and no sign of diarrhoea. Compared to unimmunised mice, the immunised mice elicited the neutralising antitoxin that markedly decreased ETEC colonisation and fluid accumulation caused by ETEC H10407 in the intestines. The immunised mice recorded higher antibody titres, including anti-CT IgG, anti-LT IgG, anti-CT-B IgG, and anti-LTB IgG. Only a two-fold rise in anti-CT/CT-B/LT/LT-B IgA was recorded in serum samples from immunised mice. No bactericidal antibodies against ETEC H10407 were detected. This investigation demonstrates the safety, immunogenicity, and cross-protective efficacy of MyCholTM against the ETEC H10407 challenge in BALB/c mice.
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12
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Differenzialdiagnose: Diarrhoe als Symptom nach Tropenaufenthalt. COLOPROCTOLOGY 2022. [DOI: 10.1007/s00053-022-00653-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Bifidobacterium longum, Lactobacillus plantarum and Pediococcus acidilactici Reversed ETEC-Inducing Intestinal Inflammation in Mice. Microorganisms 2022; 10:microorganisms10122350. [PMID: 36557603 PMCID: PMC9783104 DOI: 10.3390/microorganisms10122350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/06/2022] [Accepted: 11/17/2022] [Indexed: 11/29/2022] Open
Abstract
Microecological preparation could relieve Enterotoxigenic Escherichia coli (ETEC) K88-induced diarrhea in piglets, but which bacteria play a key role and the mitigation mechanism have not been fully clarified. In this study, 36 male mice were randomly divided into six groups (CON, K88, BK (Bifidobacterium longum + K88), LK (Lactobacillus plantarum + K88), PK (Pediococcus acidilactici + K88), and MK (mixed strains + K88)) to explore the prevention mechanisms. Three probiotic strains and their mixtures (TPSM) significantly relieved the weight loss and restored the ratio of villus height to crypt depth in the jejunum. Except for Bifidobacterium longum, other strains significantly decreased interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in mice serum. The TPSM treatment significantly downregulated the mRNA expression of the inflammatory cytokines and the Toll-like receptor and downstream gene (TLR4, MyD88, NF-κB) in jejunum induced by ETEC. Furthermore, the TPSM could restore dysbiosis of the intestinal microbiota caused by ETEC. The intestinal microbiota analysis demonstrated that Bifidobacterium longum enriched the Bifidobacterium genus (p < 0.05), Lactobacillus plantarum enriched the Lactobacillus genus (p < 0.05), Pediococcus acidilactici enriched the Coriobacteriaceae_UCG-002 and Christensenellaceae_R-7_group genus (p < 0.05), mixed bacteria enriched the Akkermansia genus (p < 0.05), but ETEC enriched the Desulfovibrio genus (p < 0.05). Meanwhile, the starch and sucrose metabolism, galactose and fructose metabolism, mannose metabolism and ABC transporters were increased with probiotics pre-treatment (p < 0.05). To sum up, the microecological preparation alleviated ETEC-induced diarrhea by regulating the immune response, rebalancing intestinal microbiota and improving carbohydrate metabolism.
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Fernandez V, Ahmed SM, Graves MC, Pender MA, Shoemaker H, Birich H, Pupaibool J, Benson LS, Leung DT. Incidence Rate and Risk Factors Associated with Travelers' Diarrhea in International Travelers Departing from Utah, USA. Am J Trop Med Hyg 2022; 107:898-903. [PMID: 35970286 PMCID: PMC9651512 DOI: 10.4269/ajtmh.21-1005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 06/01/2022] [Indexed: 11/07/2022] Open
Abstract
Despite knowledge on the causes and prevention strategies for travelers' diarrhea (TD), it continues to be one of the most common illnesses experienced by U.S. international travelers. However, studies of risk factors associated with TD among U.S. travelers are limited. In this study, we aimed to determine the incidence rate of TD, the proportion of travelers who experience TD, and to identify risk factors associated with TD. In this cross-sectional study, we collected and analyzed data from anonymous posttravel questionnaires submitted by international travelers recruited during their pretravel visit at two travel clinics in Salt Lake City, Utah, from October 2016 to March 2020. Of 571 travelers who completed posttravel surveys, 484 (85%) answered the TD question, of which 111 (23%) reported TD, for an incidence rate of 1.1 episodes per 100 travel-days (95% confidence interval [CI]: 0.9-1.4). In a multivariable model, visiting Southeast Asian (odds ratio [OR]: 2.60; 95% CI: 1.45-4.72) and African (OR: 2.06; 95% CI: 1.09-3.93]) WHO regions, having 10 or more individuals in the group (OR: 3.91; 95% CI: 1.50-11.32]), longer trip duration (OR: 1.01; 95% CI: 1.00-1.02), visiting both urban and rural destinations (OR: 1.94; 95% CI: 1.01-3.90), and taking medications/supplements to prevent TD (OR: 2.74; 95% CI: 1.69-4.47) were statistically significantly associated with increased odds of reporting TD. TD continues to be common in international travelers from the United States. Our findings provide insights regarding travelers' behaviors regarding TD in international travelers from high-income countries and shows the need for additional research into prevention strategies for travelers' diarrhea.
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Affiliation(s)
- Valerie Fernandez
- Division of Infectious Disease, University of Utah School of Medicine, Salt Lake City, Utah
| | - Sharia M. Ahmed
- Division of Infectious Disease, University of Utah School of Medicine, Salt Lake City, Utah
| | - Michael C. Graves
- Division of Infectious Disease, University of Utah School of Medicine, Salt Lake City, Utah
| | - Melissa A. Pender
- Division of Infectious Disease, University of Utah School of Medicine, Salt Lake City, Utah
| | - Holly Shoemaker
- Division of Population Health Sciences, University of Utah School of Medicine, Salt Lake City, Utah
| | - Holly Birich
- Salt Lake County Health Department, Salt Lake City, Utah
| | - Jakrapun Pupaibool
- Division of Infectious Disease, University of Utah School of Medicine, Salt Lake City, Utah
| | - L. Scott Benson
- Division of Public Health, University of Utah School of Medicine, Salt Lake City, Utah
| | - Daniel T. Leung
- Division of Infectious Disease, University of Utah School of Medicine, Salt Lake City, Utah
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15
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Muzembo BA, Kitahara K, Ohno A, Okamoto K, Miyoshi SI. Colonization with extended-spectrum beta-lactamase-producing Escherichia coli and traveler's diarrhea attack rates among travelers to India: a systematic review and meta-analysis. Trop Dis Travel Med Vaccines 2022; 8:22. [PMID: 36180932 PMCID: PMC9525155 DOI: 10.1186/s40794-022-00179-1] [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: 06/02/2022] [Accepted: 08/14/2022] [Indexed: 11/07/2022] Open
Abstract
Background India is an attractive destination for travelers. Unfortunately, numerous reports exist on traveler’s diarrhea (TD) and fecal colonization with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) among international travelers visiting India. Here, we systematically reviewed studies published on the acquisition of ESBL-EC and TD attack rates among international visitors to India. Methods Design: Systematic review and meta-analysis. A systematic search was performed using Google Scholar, PubMed, EMBASE, Web of Science, and gray literature from 2000 to December 2021, for studies containing data for ESBL-EC acquisition or TD experience related to a trip to India. Random effects models were used to compute the prevalence of ESBL-EC acquisition and TD attack. Results The literature search yielded a total of 5023 records. Of these, 31 met our inclusion criteria for systematic review and only 17 could be meta-analyzed (9 for TD, and 8 for ESBL-EC). The overall pooled attack rate of TD was 39% (95% confidence interval, CI: 25–53%). In studies where travelers' memory was used to diagnose TD, the pooled attack rate of TD was slightly higher (42%, 95% CI: 21–64%) compared to those where TD was objectively documented (33%, 95% CI: 17–49%). There were significant risks to be colonized with ESBL-EC among the travelers who experienced TD. The pooled rate of ESBL-EC colonization was 72% (CI: 67–78%). Most ESBL-EC produced CTX-M-15 enzyme. Furthermore, most of the travelers who acquired ESBL-EC were from highly industrialized countries recruited from travel clinics: Canada (n = 80), Germany (n = 69), Netherlands (n = 20), Sweden (n = 18), Japan (n = 10), Finland (n = 8), USA (n = 7), Spain (n = 5), and Denmark (n = 3). Conclusions TD pooled attack rate and ESBL-EC acquisition among international travelers visiting India were high in this study. However, we cannot make generalizations based upon this TD pooled attack rate for the current situation, due to a lack of current data. Our study highlights that travelers should be advised on TD to ensure that they do not disregard the risk of contracting TD and be better prepared as a result. It also illustrates the importance of international travel in acquiring antibiotic-resistant Escherichia coli. Supplementary Information The online version contains supplementary material available at 10.1186/s40794-022-00179-1.
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Affiliation(s)
- Basilua Andre Muzembo
- grid.261356.50000 0001 1302 4472Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushimanaka, Kita Ward, Okayama, 700-8530 Japan
| | - Kei Kitahara
- grid.261356.50000 0001 1302 4472Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushimanaka, Kita Ward, Okayama, 700-8530 Japan ,Collaborative Research Centre of Okayama University for Infectious Diseases in India, Kolkata 700010, India
| | - Ayumu Ohno
- grid.261356.50000 0001 1302 4472Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushimanaka, Kita Ward, Okayama, 700-8530 Japan ,Collaborative Research Centre of Okayama University for Infectious Diseases in India, Kolkata 700010, India
| | - Keinosuke Okamoto
- grid.261356.50000 0001 1302 4472Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushimanaka, Kita Ward, Okayama, 700-8530 Japan
| | - Shin-Ichi Miyoshi
- grid.261356.50000 0001 1302 4472Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 1-1-1 Tsushimanaka, Kita Ward, Okayama, 700-8530 Japan
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Evaluation of Multivalent Enterotoxigenic Escherichia coli Vaccine Candidate MecVax Antigen Dose-Dependent Effect in a Murine Model. Appl Environ Microbiol 2022; 88:e0095922. [PMID: 35972240 PMCID: PMC9469710 DOI: 10.1128/aem.00959-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
There are no licensed vaccines against enterotoxigenic Escherichia coli (ETEC), a leading cause of children's diarrhea and travelers' diarrhea. Recently, protein-based vaccine candidate MecVax was demonstrated to induce functional antibodies against both ETEC toxins (heat-stable toxin [STa] and heat-labile toxin [LT]) and seven ETEC adhesins (CFA/I and CS1 to CS6) and to protect against ETEC clinical diarrhea or intestinal colonization preclinically. Those studies used intraperitoneal, intramuscular, and intradermal routes, and a dose range for MecVax protein antigens, toxoid fusion 3xSTaN12S-mnLTR192G/L211A, and adhesin CFA/I/II/IV MEFA has not been investigated. Here, we further characterized MecVax broad immunogenicity, utilizing a subcutaneous route, and examined vaccine dose-dependent antibody response effects and also antibody functional activities against ETEC enterotoxicity and bacterial adherence. Data showed that mice immunized subcutaneously with MecVax developed robust IgG responses to seven ETEC adhesins (CFA/I, as well as CS1 to CS6) and two toxins (STa and LT). At a subcutaneous dose of 25, 20, or 10 μg or at an intramuscular dose of 12, 6, or 3 μg, MecVax induced similar levels IgG responses to the targeted toxins and adhesins, and these antibodies exhibited equivalent functional activities against ETEC toxin enterotoxicity and bacterial adherence. Once the intramuscular dose was decreased to 1 μg, vaccine-induced antibodies were significantly reduced and no longer neutralized STa enterotoxicity. The results indicated that MecVax administered subcutaneously is broadly immunogenic and, at an intramuscular dose of 3 μg, can induce functional antitoxin and anti-adhesin antibodies in mice, providing instructive information for future vaccine dose studies in humans and accelerating MecVax vaccine development. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) is a leading cause of children's diarrhea and the most common cause of travelers' diarrhea. ETEC infections are responsible for >200 million diarrhea clinical cases and near 100,000 deaths annually. Currently, there are no licensed vaccines for ETEC diarrhea. The protein-based vaccine candidate MecVax unprecedentedly targets two ETEC toxins (STa and LT, produced by all ETEC strains) and seven ETEC adhesins (CFA/I, as well as CS1 to CS6, associated with >60% of ETEC clinical diarrhea cases) and has been demonstrated to be broadly immunogenic and cross protective; as such, it represents a potentially effective multivalent vaccine against ETEC-associated children's and travelers' diarrhea. This study further confirmed MecVax broad immunogenicity and evaluated the vaccine antigen dose effect on the induction of antigen-specific antibody responses in mice and on antibody functional activities against ETEC toxin enterotoxicity and bacterial adherence, yielding useful information for future human volunteer studies and the development of MecVax as an effective ETEC vaccine.
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Upadhyay I, Lauder KL, Li S, Ptacek G, Zhang W. Intramuscularly Administered Enterotoxigenic Escherichia coli (ETEC) Vaccine Candidate MecVax Prevented H10407 Intestinal Colonization in an Adult Rabbit Colonization Model. Microbiol Spectr 2022; 10:e0147322. [PMID: 35762781 PMCID: PMC9431210 DOI: 10.1128/spectrum.01473-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/14/2022] [Indexed: 11/20/2022] Open
Abstract
Currently, there are no vaccines licensed for enterotoxigenic Escherichia coli (ETEC), a leading cause of children's diarrhea in developing countries and the most common cause of travelers' diarrhea. A vaccine preventing ETEC bacteria from colonization at small intestines and neutralizing enterotoxin toxicity is expected to be effective against ETEC diarrhea. Protein-based multivalent vaccine candidate MecVax was demonstrated recently to induce antibodies neutralizing heat-labile toxin (LT) and heat-stable toxin (STa) enterotoxicity and inhibiting adherence of seven ETEC adhesins (CFA/I, CS1 to CS6) but also to protect against ETEC toxin-mediated clinical diarrhea in a pig challenge model. To further evaluate MecVax preclinical efficacy against ETEC colonization at small intestines, in this study, we intramuscularly immunized adult rabbits with MecVax, challenged rabbits with ETEC strain H10407 (CFA/I, LT, STa), and examined prevention of bacteria intestinal colonization. Data showed that rabbits immunized with MecVax developed antibodies to both ETEC toxins (LT, STa) and seven adhesins (CFA/I, CS1 to CS6) and had over 99.9% reduction of H10407 intestinal colonization, indicating that the broadly immunogenic ETEC vaccine candidate MecVax is protective against ETEC H10407 intestinal colonization. This study also confirmed that parenteral administration of a protein-based vaccine can prevent bacteria intestinal colonization. Protection against ETEC intestinal colonization demonstrated by this rabbit study, in conjugation with protection against ETEC enterotoxin-mediated clinical diarrhea from a previous pig challenge study, suggested that MecVax can potentially be an effective ETEC vaccine and a combined pig and rabbit challenge model can evaluate ETEC vaccine preclinical efficacy. IMPORTANCE An effective ETEC vaccine would prevent hundreds of millions of diarrhea clinical cases and save nearly 100,000 lives annually. MecVax, a protein-based injectable multivalent ETEC vaccine candidate, has been shown for the first time to induce functional antibodies against both ETEC enterotoxins (STa, LT) produced by all ETEC strains and seven ETEC adhesins (CFA/I, CS1 to CS6) expressed by ETEC strains causing a majority of ETEC diarrhea clinical cases and the moderate-to-severe cases. Moreover, MecVax was demonstrated to protect against ETEC STa or LT toxin-mediated diarrhea in a pig model. If it also protects against ETEC intestinal colonization, MecVax can be validated as an effective ETEC vaccine candidate. This adult rabbit colonization model study showed that intramuscular administration of MecVax effectively prevented intestinal colonization by H10407, perhaps the most virulent ETEC strain, affirming MecVax vaccine candidacy and accelerating vaccine development against ETEC children's diarrhea and travelers' diarrhea.
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Affiliation(s)
- Ipshita Upadhyay
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
| | - Kathryn L. Lauder
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
| | - Siqi Li
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
| | - Galen Ptacek
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
| | - Weiping Zhang
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
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Ross AG, Khanam F, Islam MT, Chowdhury F, Sleigh AC. Diagnosis and Management of Acute Enteropathogens in Returning Travelers. Int J Infect Dis 2022; 123:34-40. [DOI: 10.1016/j.ijid.2022.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/29/2022] [Accepted: 08/01/2022] [Indexed: 10/16/2022] Open
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Sukrama IDM, Pinatih KJP, Hendrayana MA, Rasyid B, Wedari NLPH. Escherichia coli Clonal Variability Based on Genetic Diversity Pattern with Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction Methods for Traveler’s Diarrhea Cases in Bali. Open Access Maced J Med Sci 2022. [DOI: 10.3889/oamjms.2022.8990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND: Bali is a favorite tourism destination in the world. As a major tourist destination, the incidence of illness that afflicts tourists greatly affects the image of tourism. Diarrhea is a health problem that is most often experienced and is a major obstacle for foreign tourists when traveling, especially to Bali. Escherichia coli (E. coli) bacteria cause diarrhea more often than viruses in some developing countries. Genetic differences can affect the characteristics of E. coli, especially in relation to the medical field.
AIM: We would like to assess the genetic diversity of the different pathogenic E. coli from various clinical isolates including those from traveler’s diarrhea in Bali, Indonesia.
MATERIALS AND METHODS: One of the molecular techniques used in this study is to use enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The sample in this study was the feces of foreign tourists with traveler’s diarrhea in Bali. This study carried out research procedures in the form of Isolation of E. coli genome DNA from culture, amplification of E. coli 16S rRNA encoding genes, sequencing of E. coli 16S rRNA encoding genes, phylogenetic tree construction, and then analysis of E. coli genetic diversity with ERIC-PCR sequences.
RESULTS: The results showed that the ERIC-PCR method was more discriminatory than other methods to analyze the genetic diversity of E. coli from fecal samples of patients with traveler’s diarrhea. It was found that clonal variability based on the genetic similarity of all sample E. coli isolates varied from 0% to 100%.
CONCLUSIONS: This shows that the source of transmission and the strains of E. coli that cause it comes from diverse populations.
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Lόpez-Vélez R, Lebens M, Bundy L, Barriga J, Steffen R. Bacterial travellers' diarrhoea: A narrative review of literature published over the past 10 years. Travel Med Infect Dis 2022; 47:102293. [PMID: 35247581 DOI: 10.1016/j.tmaid.2022.102293] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/24/2022] [Accepted: 02/28/2022] [Indexed: 02/04/2023]
Abstract
Travellers' diarrhoea (TD) is the most frequent illness experienced by international travellers to lower-income countries with bacterial agents considered to account for 80-90% of cases. In this review, we summarise evidence published on bacterial TD over the past 10 years, focusing on the epidemiology and aetiology of TD. Diarrhoeagenic Escherichia coli (DEC) continue to be the most commonly implicated bacteria in TD, although Enteropathogenic E. coli (EPEC) and Enteroaggregative E. coli (EAEC) now appear to be predominant where Enterotoxigenic E. coli (ETEC) was previously considered most prevalent globally. Where fluroquinolone resistance had primarily been documented for Campylobacter in Southeast Asia, widespread resistance has been observed in most regions of the world for multiple enteropathogens, including Shigella, Salmonella, ETEC and EAEC. Implementation of novel molecular methods for pathogen detection has led to identification of bacterial pathogens, including Clostridium difficile (with and without the use of prior antibiotics), Arcobacter species and Bacteroides fragilis, as aetiological agents in TD. The widespread resistance to first-line antibiotics in multiple bacterial enteropathogens warrants continued surveillance and re-evaluation of current treatment practices. Further investigations are required to determine the prevalence and geographical distribution of bacterial enteropathogens that have been more recently implicated in TD.
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Affiliation(s)
- Rogelio Lόpez-Vélez
- National Referral Unit for Tropical Diseases, Infectious Diseases Department, Ramón y Cajal University Hospital, IRYCIS, 28034, Madrid, Spain.
| | - Michael Lebens
- Department of Microbiology and Immunology, University of Gothenburg, Box 435, SE-40530, Gothenburg, Sweden.
| | - Leah Bundy
- Elements Communications Ltd, Westerham, TN16 1RQ, UK.
| | - Juan Barriga
- Department of Medical Affairs Europe, Emergent BioSolutions, 1455, Madrid, Spain.
| | - Robert Steffen
- Epidemiology, Biostatistics and Prevention Institute, World Health Organization Collaborating Centre for Travelers' Health, University of Zurich, Hirschengraben 84, CH-8001, Zurich, Switzerland; Epidemiology, Human Genetics and Environmental Sciences Division, University of Texas School of Public Health, Houston, TX 77030, Texas, USA.
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21
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Intradermally administered enterotoxigenic E. coli vaccine candidate MecVax induces functional serum IgG antibodies against seven adhesins (CFA/I, CS1-CS6) and both toxins (STa, LT). Appl Environ Microbiol 2021; 88:e0213921. [PMID: 34936832 DOI: 10.1128/aem.02139-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
There are no vaccines licensed for enterotoxigenic Escherichia coli (ETEC), a leading bacterial cause of children's diarrhea and travelers' diarrhea. MecVax, a multivalent E. coli vaccine candidate composed of two epitope- and structure-based polyvalent proteins (toxoid fusion 3xSTaN12S-mnLTR192G/L211A and CFA/I/II/IV MEFA), is to induce broad anti-adhesin and antitoxin antibodies against heterogeneous ETEC pathovars. Administered intraperitoneally (IP) or intramuscularly (IM), MecVax was shown to induce antibodies against seven ETEC adhesins (CFA/I, CS1-CS6), which are produced by ETEC pathovars causing over 60% of ETEC-associated diarrheal cases and the moderate-to-severe cases, and both toxins (heat-labile toxin - LT and heat-stable toxin - STa) expressed by all ETEC strains. To further characterize immunogenicity of this protein-based injectable subunit vaccine candidate and to explore other parenteral administration routes for the product, in this study, we intradermally (ID) immunized mice with MecVax and measured antigen-specific antibody responses and further antibody functional activities against the adhesins and toxins targeted by the vaccine. Data showed that mice ID immunized with MecVax developed robust anti-CFA/I, -CS1, -CS2, -CS3, -CS4, -CS5, -CS6, -LT and anti-STa IgG responses. Furthermore, antibodies derived from MecVax via ID route inhibited adherence of ETEC or E. coli strains expressing any of the seven target adhesins (CFA/I, CS1-CS6) and neutralized enterotoxicity of LT and STa toxins. These results confirmed broad immunogenicity of MecVax and suggested that this multivalent ETEC subunit vaccine candidate can be effectively delivered via ID route. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) is a leading bacterial cause of diarrhea in children living in developing countries and international travelers. Developing an effective vaccine for ETEC diarrhea has been hampered because of challenges of virulence heterogeneity and difficulties of inducing neutralizing antibodies against the key STa toxin. MecVax, a subunit vaccine candidate carrying two polyvalent protein antigens for the first time induces functional antibodies against the most important ETEC adhesins which are associated with a majority of diarrheal cases and the moderate-to-severe cases but also against enterotoxicity of LT and more importantly STa toxin which plays a key role in children's diarrhea and travelers' diarrhea, potentially leading to development of a truly effective ETEC vaccine. Data from this study may also indicated that this ETEC subunit vaccine can be administered effectively via ID route, expanding clinical administration options for this vaccine product.
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22
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Schüroff PA, Salvador FA, Abe CM, Wami HT, Carvalho E, Hernandes RT, Dobrindt U, Gomes TAT, Elias WP. The aggregate-forming pili (AFP) mediates the aggregative adherence of a hybrid-pathogenic Escherichia coli (UPEC/EAEC) isolated from a urinary tract infection. Virulence 2021; 12:3073-3093. [PMID: 34923895 PMCID: PMC8923075 DOI: 10.1080/21505594.2021.2007645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Enteroaggregative Escherichia coli (EAEC) comprises an important diarrheagenic pathotype, while uropathogenic E. coli (UPEC) is the most important agent of urinary tract infection (UTI). Recently, EAEC virulence factors have been detected in E. coli strains causing UTI, showing the importance of these hybrid-pathogenic strains. Previously, we detected an E. coli strain isolated from UTI (UPEC-46) presenting characteristics of EAEC, e.g., the aggregative adherence (AA) pattern and EAEC-associated genes (aatA, aap, and pet). In this current study, we analyzed the whole genomic sequence of UPEC-46 and characterized some phenotypic traits. The AA phenotype was observed in cell lineages of urinary and intestinal origin. The production of curli, cellulose, bacteriocins, and Pet toxin was detected. Additionally, UPEC-46 was not capable of forming biofilm using different culture media and human urine. The genome sequence analysis showed that this strain belongs to serotype O166:H12, ST10, and phylogroup A, harbors the tet, aadA, and dfrA/sul resistance genes, and is phylogenetically more related to EAEC strains isolated from human feces. UPEC-46 harbors three plasmids. Plasmid p46-1 (~135 kb) carries some EAEC marker genes and those encoding the aggregate-forming pili (AFP) and its regulator (afpR). A mutation in afpA (encoding the AFP major pilin) led to the loss of pilin production and assembly, and notably, a strongly reduced adhesion to epithelial cells. In summary, the genetic background and phenotypic traits analyzed suggest that UPEC-46 is a hybrid strain (UPEC/EAEC) and highlights the importance of AFP adhesin in the adherence to colorectal and bladder cell lines.
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Affiliation(s)
- Paulo A Schüroff
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil.,Institute of Hygiene, University of Münster, Münster, Germany
| | - Fábia A Salvador
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Cecilia M Abe
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Haleluya T Wami
- Institute of Hygiene, University of Münster, Münster, Germany
| | - Eneas Carvalho
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
| | - Rodrigo T Hernandes
- Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, Brazil
| | - Ulrich Dobrindt
- Institute of Hygiene, University of Münster, Münster, Germany
| | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Waldir P Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
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Effects of IQW and IRW on Inflammation and Gut Microbiota in ETEC-Induced Diarrhea. Mediators Inflamm 2021; 2021:2752265. [PMID: 34602857 PMCID: PMC8486560 DOI: 10.1155/2021/2752265] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/26/2021] [Accepted: 08/30/2021] [Indexed: 12/20/2022] Open
Abstract
Methods The mice were randomly distributed into four groups: (a) control (CTRL) group, (b) ETEC group, (c) IQW-ETEC group, and (d) IRW-ETEC group. Villus length and crypt depth were measured after hematoxylin and eosin staining. The inflammatory reaction was analyzed via inflammatory cytokines (i.e., TNF-α, IL-1β, IL-6, and IL-10) using the enzyme-linked immunosorbent assay (ELISA). The microbiota in the colon was sequenced using 16S ribosomal RNA. Results The villus length decreased, the crypt depth decreased, and the expression of inflammatory cytokines (i.e., TNF-α, IL-1β, IL-6, and IL-10) increased due to ETEC. In the IRW-ETEC and IQW-ETEC groups, the Shannon index decreased (P < 0.05). IQW and IRW increased the abundance of Firmicutes, Proteobacteria, Clostridiales, Lachnospiraceae, and Alloprevotella; contrastingly, it decreased the abundance of Epsilonproteobacteria, Erysipelotrichales, Prevotellaceae, and Flavobacteriaceae compared to the ETEC group (P <0.05). Conclusion This study ascertained that the addition of IQW and IRW could alleviate jejunal inflammation and increase microbiota community diversity.
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24
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Wendt S, Beier D, Paquet D, Trawinski H, Fuchs A, Lübbert C. Medical Advice for Travelers. DEUTSCHES ARZTEBLATT INTERNATIONAL 2021; 118:349–356. [PMID: 33597073 DOI: 10.3238/arztebl.m2021.0127] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND In 2019, 1.5 billion international tourist trips were counted worldwide. Germany, with 70.8 million vacations lasting ≥ 5 days, was one of the populations most willing to travel. These days, even elderly and multimorbid persons regularly travel long-distance, which can be associated with significant health risks. By advising travelers and implementing preventive measures, the risk of illness can be reduced significantly. METHODS A selective survey of PubMed was performed to identify publications on medical advice for travelers between 2000 and 2020. We included guidelines, studies, and recommendations that mainly deal with the preventive aspects of travel medicine and have a high level of practical relevance and the highest possible level of evidence. Previously published guidelines (based on the GRADE criteria) were adopted, and recommendations not based on the results of scientific studies were characterized as Good Clinical Practice (GCP). RESULTS Many medical recommendations for travelers still rely on individualized, experience-based, or consensus-based assessments. Apart from a review of medical history and vaccination status, a risk analysis is performed, travel fitness is evaluated individually, and a prevention plan is designed. Particular attention is devoted to malaria prophylaxis, vector protection, and traveler's diarrhea. Medical advice before travel is especially important for the elderly, children, pregnant women, the chronically ill, long-term and adventure travelers as well as migrants from malaria-endemic areas who are returning home. CONCLUSION The health risks associated with travel can be minimized by specialist medical advice. Many recommendations are empirical in nature and require further research.
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25
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Abdel-Haq N, Asmar BI. Fever in the Returned Pediatric Traveler. Glob Pediatr Health 2021; 8:2333794X211026188. [PMID: 34423077 PMCID: PMC8375340 DOI: 10.1177/2333794x211026188] [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: 05/26/2021] [Accepted: 05/30/2021] [Indexed: 11/15/2022] Open
Abstract
Global mobility has been steadily increasing in recent years. The assessment of the febrile child returning from international travel is a diagnostic challenge. The COVID-19 pandemic has profoundly affected international travel and made evaluation and management of the sick returned traveler more challenging. Children visiting friends and relatives abroad remain at higher risk of infection compared to tourists. This review presents a guidance on the initial assessment of a traveling febrile child including interpretation of medical history, physical examination, and laboratory findings. Important clues to etiology include exposure to different infectious agents, incubation periods of pathogens, and prophylaxis regimens and vaccines received. Early identification of potentially life-threatening and highly contagious infections is essential. In this article, we discuss the epidemiology, evaluation, and management of specific travel related infections such as malaria, typhoid fever, dengue fever, viral hemorrhagic fever, rickettsiosis, leptospirosis, schistosomiasis, gastrointestinal, and respiratory infections.
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Affiliation(s)
- Nahed Abdel-Haq
- Children’s Hospital of Michigan, Detroit, MI, USA
- Central Michigan University, Mount Pleasant, MI, USA
- Wayne State University, Detroit, MI, USA
| | - Basim I. Asmar
- Children’s Hospital of Michigan, Detroit, MI, USA
- Central Michigan University, Mount Pleasant, MI, USA
- Wayne State University, Detroit, MI, USA
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26
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Midgett CR, Talbot KM, Day JL, Munson GP, Kull FJ. Structure of the master regulator Rns reveals an inhibitor of enterotoxigenic Escherichia coli virulence regulons. Sci Rep 2021; 11:15663. [PMID: 34341412 PMCID: PMC8329261 DOI: 10.1038/s41598-021-95123-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 07/14/2021] [Indexed: 02/07/2023] Open
Abstract
Enteric infections caused by the gram-negative bacteria enterotoxigenic Escherichia coli (ETEC), Vibrio cholerae, Shigella flexneri, and Salmonella enterica are among the most common and affect billions of people each year. These bacteria control expression of virulence factors using a network of transcriptional regulators, some of which are modulated by small molecules as has been shown for ToxT, an AraC family member from V. cholerae. In ETEC the expression of many types of adhesive pili is dependent upon the AraC family member Rns. We present here the 3 Å crystal structure of Rns and show it closely resembles ToxT. Rns crystallized as a dimer via an interface similar to that observed in other dimeric AraC's. Furthermore, the structure of Rns revealed the presence of a ligand, decanoic acid, that inhibits its activity in a manner similar to the fatty acid mediated inhibition observed for ToxT and the S. enterica homologue HilD. Together, these results support our hypothesis that fatty acids regulate virulence controlling AraC family members in a common manner across a number of enteric pathogens. Furthermore, for the first time this work identifies a small molecule capable of inhibiting the ETEC Rns regulon, providing a basis for development of therapeutics against this deadly human pathogen.
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Affiliation(s)
| | - Kacey Marie Talbot
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Jessica L Day
- Department of Chemistry, Dartmouth College, Hanover, NH, USA
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - George P Munson
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - F Jon Kull
- Department of Chemistry, Dartmouth College, Hanover, NH, USA.
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Ikeuchi S, Hien BT, Thuan NK, Thi L, Hara-Kudo Y, Taniguchi T, Hayashidani H. [Contamination of Pathogenic Escherichia coli in Retail Fresh Vegetables in the Mekong Delta, Vietnam]. Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) 2021; 62:94-99. [PMID: 34219102 DOI: 10.3358/shokueishi.62.94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
From July 2017 to January 2019, total of 645 retail fresh vegetables collected from 19 retail shops and markets was investigated to know the contamination of enterohemorrhagic Escherichia coli (EHEC) and enterotoxigenic E. coli (ETEC). Of 645 samples, 2 samples (0.3%) were positive for pathogenic E. coli. Of 2 pathogenic E. coli positive samples, 1 was EHEC (stx2 positive) and the other was ETEC (sta positive). Two pathogenic E. coli strains were isolated from crisphead lettuce. EHEC strain was not serotyped by commercial antisera and ETEC was serotyped as O20. EHEC and ETEC strains showed multi-drug resistance against 4 and 7 antibiotics, respectively. These results indicate that retail fresh vegetables seem to be not an important source of human EHEC and ETEC infection in the Mekong Delta, Vietnam.
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Affiliation(s)
- Shunsuke Ikeuchi
- Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agricultureand Technology
| | - Bui Thi Hien
- Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology
| | - Nguyen Khanh Thuan
- Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology.,Department of Veterinary Medicine, College of Agriculture, Cantho University
| | - Ly Thi
- Department of Veterinary Medicine, College of Agriculture, Cantho University
| | | | - Takahide Taniguchi
- Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agricultureand Technology.,Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology
| | - Hideki Hayashidani
- Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agricultureand Technology.,Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology
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28
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Preclinical Characterization of Immunogenicity and Efficacy against Diarrhea from MecVax, a Multivalent Enterotoxigenic E. coli Vaccine Candidate. Infect Immun 2021; 89:e0010621. [PMID: 33875477 DOI: 10.1128/iai.00106-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
There are no vaccines licensed for enterotoxigenic Escherichia coli (ETEC), a leading cause of diarrhea for children in developing countries and international travelers. Virulence heterogeneity among strains and difficulties identifying safe antigens for protective antibodies against STa, a potent but poorly immunogenic heat-stable toxin which plays a key role in ETEC diarrhea, are challenges in ETEC vaccine development. To overcome these challenges, we applied a toxoid fusion strategy and a novel epitope- and structure-based multiepitope fusion antigen (MEFA) vaccinology platform to construct two chimeric multivalent proteins, toxoid fusion 3xSTaN12S-mnLTR192G/L211A and adhesin CFA/I/II/IV MEFA, and demonstrated that the proteins induced protective antibodies against STa and heat-labile toxin (LT) produced by all ETEC strains or the seven most important ETEC adhesins (CFA/I and CS1 to CS6) expressed by the ETEC strains causing 60 to 70% of diarrheal cases and moderate to severe cases. Combining two proteins, we prepared a protein-based multivalent ETEC vaccine, MecVax. MecVax was broadly immunogenic; mice and pigs intramuscularly immunized with MecVax developed no apparent adverse effects but had robust antibody responses to the target toxins and adhesins. Importantly, MecVax-induced antibodies were broadly protective, demonstrated by significant adherence inhibition against E. coli bacteria producing any of the seven adhesins and neutralization of STa and cholera toxin (CT) enterotoxicity. Moreover, MecVax protected against watery diarrhea and provided over 70% and 90% protection against any diarrhea from an STa-positive or an LT-positive ETEC strain in a pig challenge model. These results indicated that MecVax induces broadly protective antibodies and prevents diarrhea preclinically, signifying that MecVax is potentially an effective injectable vaccine for ETEC. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) bacteria are a top cause of children's diarrhea and travelers' diarrhea and are responsible for over 220 million diarrheal cases and more than 100,000 deaths annually. A safe and effective ETEC vaccine can significantly improve public health, particularly in developing countries. Data from this preclinical study showed that MecVax induces broadly protective antiadhesin and antitoxin antibodies, becoming the first ETEC vaccine candidate to induce protective antibodies inhibiting adherence of the seven most important ETEC adhesins and neutralizing the enterotoxicity of not only LT but also STa toxin. More importantly, MecVax is shown to protect against clinical diarrhea from STa-positive or LT-positive ETEC infection in a pig challenge model, recording protection from antibodies induced by the protein-based, injectable, subunit vaccine MecVax against ETEC diarrhea and perhaps the possibility of intramuscularly administered protein vaccines for protection against intestinal mucosal infection.
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Abstract
Acute bacterial gastroenteritis is among the most common infections worldwide, with millions of infections annually in the United States. Much of the illness is foodborne, occurring as both sporadic cases and large multistate outbreaks. Pathogen evolution through genetic exchange of virulence traits and antibiotic resistance determinants poses challenges for empiric therapy. Culture-independent diagnostic tests in clinical laboratories afford rapid diagnosis and expanded identification of pathogens. However, cultures remain important to generate sensitivity data and strain archiving for outbreak investigations. Most infections are self-limited, permitting judicious selection of antibiotic use in more severe forms of illness.
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Affiliation(s)
- James M Fleckenstein
- Department of Medicine, Division of Infectious Diseases, Washington University in Saint Louis, School of Medicine, Campus Box 8051, 660 South Euclid Avenue, Saint Louis, MO 63110, USA; Infectious Disease Section, Medicine Service, Veterans Affairs Saint Louis Health Care System, 915 North Grand Boulevard, Saint Louis, MO 63106, USA.
| | - F Matthew Kuhlmann
- Department of Medicine, Division of Infectious Diseases, Washington University in Saint Louis, School of Medicine, Campus Box 8051, 660 South Euclid Avenue, Saint Louis, MO 63110, USA
| | - Alaullah Sheikh
- Department of Medicine, Division of Infectious Diseases, Washington University in Saint Louis, School of Medicine, Campus Box 8051, 660 South Euclid Avenue, Saint Louis, MO 63110, USA
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30
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Ashbaugh HR, Early JM, Johnson ME, Simons MP, Graf PCF, Riddle MS, Swierczewski BE, For The Gtd Study Team. A Multisite Network Assessment of the Epidemiology and Etiology of Acquired Diarrhea among U.S. Military and Western Travelers (Global Travelers' Diarrhea Study): A Principal Role of Norovirus among Travelers with Gastrointestinal Illness. Am J Trop Med Hyg 2020; 103:1855-1863. [PMID: 32959765 PMCID: PMC7646805 DOI: 10.4269/ajtmh.20-0053] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
U.S. military personnel must be ready to deploy to locations worldwide, including environments with heightened risk of infectious disease. Diarrheal illnesses continue to be among the most significant infectious disease threats to operational capability. To better prevent, detect, and respond to these threats and improve synchronization across the Department of Defense (DoD) overseas laboratory network, a multisite Global Travelers’ Diarrhea protocol was implemented with standardized case definitions and harmonized laboratory methods to identify enteric pathogens. Harmonized laboratory procedures for detection of Norovirus (NoV), enterotoxigenic Escherichia coli (ETEC), enteroaggregative E. coli, Shiga toxin–producing E. coli, enteropathogenic E. coli, Salmonella enterica, Shigella/enteroinvasive E. coli, and Campylobacter jejuni have been implemented at six DoD laboratories with surveillance sites in Egypt, Honduras, Peru, Nepal, Thailand, and Kenya. Samples from individuals traveling from wealthy to poorer countries were collected between June 2012 and May 2018, and of samples with all variables of interest available (n = 410), most participants enrolled were students (46%), tourists (26%), U.S. military personnel (13%), or other unspecified travelers (11%). One or more pathogens were detected in 59% of samples tested. Of samples tested, the most commonly detected pathogens were NoV (24%), ETEC (16%), and C. jejuni (14%), suggesting that NoV plays a larger role in travelers’ diarrhea than has previously been described. Harmonized data collection and methods will ensure identification and characterization of enteric pathogens are consistent across the DoD laboratory network, ultimately resulting in more comparable data for global assessments, preventive measures, and treatment recommendations.
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Affiliation(s)
- Hayley R Ashbaugh
- Public Health Directorate, Armed Forces Health Surveillance Division, Global Emerging Infections Surveillance, Silver Spring, Maryland
| | - June M Early
- General Dynamics Information Technology, Silver Spring, Maryland.,Public Health Directorate, Armed Forces Health Surveillance Division, Global Emerging Infections Surveillance, Silver Spring, Maryland
| | - Myles E Johnson
- General Dynamics Information Technology, Silver Spring, Maryland.,Public Health Directorate, Armed Forces Health Surveillance Division, Global Emerging Infections Surveillance, Silver Spring, Maryland
| | - Mark P Simons
- Naval Medical Research Center, Silver Spring, Maryland
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Abstract
Enteric viral and bacterial infections continue to be a leading cause of mortality and morbidity in young children in low-income and middle-income countries, the elderly, and immunocompromised individuals. Vaccines are considered an effective and practical preventive approach against the predominantly fecal-to-oral transmitted gastroenteritis particularly in the resource-limited countries or regions where implementation of sanitation systems and supply of safe drinking water are not quickly achievable. While vaccines are available for a few enteric pathogens including rotavirus and cholera, there are no vaccines licensed for many other enteric viral and bacterial pathogens. Challenges in enteric vaccine development include immunological heterogeneity among pathogen strains or isolates, a lack of animal challenge models to evaluate vaccine candidacy, undefined host immune correlates to protection, and a low protective efficacy among young children in endemic regions. In this article, we briefly updated the progress and challenges in vaccines and vaccine development for the leading enteric viral and bacterial pathogens including rotavirus, human calicivirus, Shigella, enterotoxigenic Escherichia coli (ETEC), cholera, nontyphoidal Salmonella, and Campylobacter, and introduced a novel epitope- and structure-based vaccinology platform known as MEFA (multiepitope fusion antigen) and the application of MEFA for developing broadly protective multivalent vaccines against heterogenous pathogens.
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Affiliation(s)
- Hyesuk Seo
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
| | - Qiangde Duan
- University of Yangzhou, Institute of Comparative Medicine, Yangzhou, PR China
| | - Weiping Zhang
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA,CONTACT Weiping Zhang, University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
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32
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Wiemer D, Schwarz NG, Burchard GD, Frickmann H, Loderstaedt U, Hagen RM. Surveillance of enteropathogenic bacteria, protozoa and helminths in travellers returning from the tropics. Eur J Microbiol Immunol (Bp) 2020; 10:147-155. [PMID: 32910786 PMCID: PMC7592519 DOI: 10.1556/1886.2020.00015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/11/2020] [Indexed: 11/19/2022] Open
Abstract
Diarrhoea is a frequent symptom associated with travelling to tropical regions, but the cause is often not found. Epidemiology was assessed including up-to-date real-time PCR approaches.We analysed datasets of 528 patients who presented at the Bernhard Nocht Institute for Tropical Medicine in Hamburg, Germany, between 2006 and 2010 for screening purposes or because of diarrhoea. Stool samples were obtained and investigated by microscopy, bacterial culture, two PCR assays targeting Entamoeba histolytica, Entamoeba dispar, Giardia duodenalis, and Cryptosporidium parvum, or Salmonella spp., Shigella/EIEC spp., Campylobacter jejuni, and Yersinia spp.Among patients with gastrointestinal symptoms, 51% tested positive for bacteria or parasites, of which 66% had a known enteropathogenic potential. In patients without diarrhoea, 53% (n = 80) were positive, and 33% of these cases harboured agents of pathogenic potential. Association with clinical symptoms was primarily found for bacterial infections. Blastocystis hominis, however, was more frequent in asymptomatic than in symptomatic travellers.In conclusion, the study stresses the etiological relevance of bacterial gastroenteritis in travellers returning from the tropics, the need for molecular approaches to increase diagnostic sensitivity and demonstrates that asymptomatic carriage of enteropathogens after prolonged stays in the tropics is similarly frequent compared with symptomatic infections in travellers.
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Affiliation(s)
- Dorothea Wiemer
- 1Department of Tropical Medicine at the Bernhard Nocht Institute, Bundeswehr Hospital Hamburg, Hamburg, Germany
| | | | | | - Hagen Frickmann
- 1Department of Tropical Medicine at the Bernhard Nocht Institute, Bundeswehr Hospital Hamburg, Hamburg, Germany.,3Institute for Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
| | | | - Ralf-Matthias Hagen
- 4Department for Microbiology and Hospital Hygiene, Bundeswehr Central Hospital Koblenz, Koblenz, Germany
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Brehm TT, Lütgehetmann M, Tannich E, Addo MM, Lohse AW, Rolling T, Vinnemeier CD. Risk factors for different intestinal pathogens among patients with traveler's diarrhea: A retrospective analysis at a German travel clinic (2009-2017). Travel Med Infect Dis 2020; 37:101706. [PMID: 32353630 DOI: 10.1016/j.tmaid.2020.101706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 03/27/2020] [Accepted: 04/24/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND Travelers' diarrhea (TD) is the most common illness experienced by travelers to developing regions of the world and may be caused by bacterial, parasitic or viral pathogens. The available diagnostic tests include stool microscopy for parasitic infections, culture-dependent methods for bacterial infections and molecular methods for bacterial, parasitic and viral infections. METHOD We retrospectively evaluated demographic, clinical and microbiological data of patients presenting with TD at our travel clinic between 2009 and 2017. RESULTS Among 676 patients with TD included in our study, at least one etiologic agent was found in 21% (n = 145) of cases. In total, 195 enteropathogens were detected of which 110 were bacteria, 70 protozoa and 15 helminths. Bacterial infections were significantly more common when symptoms were present less than 14 days and travel duration did not exceed 29 days. Protozoa and helminths were predominantly detected in patients with longer lasting complaints. After stool culture was replaced by a multiplex-PCR gastrointestinal pathogen panel (GPP) at our center, significantly more intestinal bacterial pathogens were detected. CONCLUSIONS Our results support an individualized approach in the diagnostic workup of patients with TD taking host and travel characteristics into account to avoid unnecessary diagnostic testing. Molecular culture-independent diagnostic stool tests provide better coverage of the variety of etiological agents than traditional stool culture and have the benefit of rapid detection. However, the high sensitivity bears challenges differentiating colonization from infection.
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Affiliation(s)
- Thomas Theo Brehm
- Division of Infectious Diseases, I. Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20249, Hamburg, Germany; German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Germany.
| | - Marc Lütgehetmann
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Centre Hamburg-Eppendorf, Martinistraße 52, 20249, Hamburg, Germany; German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Germany.
| | - Egbert Tannich
- National Reference Centre for Tropical Pathogens, Bernhard-Nocht-Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359, Hamburg, Germany; German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Germany.
| | - Marylyn M Addo
- Division of Infectious Diseases, I. Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20249, Hamburg, Germany; Department for Clinical Immunology of Infectious Diseases, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany; German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Germany.
| | - Ansgar W Lohse
- I. Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20249, Hamburg, Germany; German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Germany.
| | - Thierry Rolling
- Division of Infectious Diseases, I. Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20249, Hamburg, Germany; German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Germany.
| | - Christof D Vinnemeier
- Division of Tropical Medicine, I. Department of Internal Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20249, Hamburg, Germany; German Centre for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Germany.
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Tan K, Deng D, Ma X, Cui Y, Tian Z. Pediococcus acidilactici P25 Protected Caenorhabditis elegans against Enterotoxigenic Escherichia coli K88 Infection and Transcriptomic Analysis of Its Potential Mechanisms. BIOMED RESEARCH INTERNATIONAL 2020; 2020:7340312. [PMID: 32337270 PMCID: PMC7150717 DOI: 10.1155/2020/7340312] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/11/2020] [Indexed: 02/07/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) K88 is a zoonotic pathogen. Previous studies have shown that lactic acid bacteria (LAB) have great potential in promoting health and resisting pathogenic infections; however, relatively little research has been done on the Pediococcus genus of LAB. This study is aimed at exploring the mechanisms imparted by Pediococcus acidilactici P25 against ETEC K88 in Caenorhabditis elegans. The probiotic performance of P25 was investigated in vitro. Colonization of K88 in the intestinal tract of C. elegans and abundance of enterotoxin genes were measured. In addition, the transcriptome of C. elegans infected by K88 was analyzed. The result showed that P25 possessed the ability to produce acid, as well as high tolerances to acidic and high bile salt concentrations. Coculture revealed that the growth of ETEC K88 was significantly inhibited by the presence of P25. The median survival of C. elegans fed P25 was 2 days longer than the group infected with K88 alone (P < 0.01). At the same time, the number of colonizing K88 and the abundances of estB and elt were reduced by up to 71.70% and 2.17 times, respectively, by P25. Transcriptome data indicated that P25 affected expression of genes relative to innate immune response and upregulated the abundance of genes in multiple pathways of C. elegans, including peroxisome, longevity, and mitogen-activated protein kinase (MAPK) pathways. These results demonstrated that in the presence of P25, K88 colonization and their expression of enterotoxin genes were reduced. This was accomplished through the alteration of environmental parameters (pH and bile salt) as well as through the promotion of the innate immune response processes, increased longevity, and increased antipathogenic bacteria-related pathways. This work highlights the potential application of P. acidilactici P25 as a probiotic resistant to ETEC K88.
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Affiliation(s)
- Keqin Tan
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science (South China) of Ministry of Agriculture, Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, China 510640
| | - Dun Deng
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science (South China) of Ministry of Agriculture, Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, China 510640
| | - Xianyong Ma
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science (South China) of Ministry of Agriculture, Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, China 510640
| | - Yiyan Cui
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science (South China) of Ministry of Agriculture, Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, China 510640
| | - Zhimei Tian
- Institute of Animal Science, Guangdong Academy of Agricultural Sciences, State Key Laboratory of Livestock and Poultry Breeding, The Key Laboratory of Animal Nutrition and Feed Science (South China) of Ministry of Agriculture, Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangdong Engineering Technology Research Center of Animal Meat Quality and Safety Control and Evaluation, Guangzhou, China 510640
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A new human challenge model for testing heat-stable toxin-based vaccine candidates for enterotoxigenic Escherichia coli diarrhea - dose optimization, clinical outcomes, and CD4+ T cell responses. PLoS Negl Trop Dis 2019; 13:e0007823. [PMID: 31665141 PMCID: PMC6844497 DOI: 10.1371/journal.pntd.0007823] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 11/11/2019] [Accepted: 10/02/2019] [Indexed: 12/17/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are a common cause of diarrheal illness in young children and travelers. There is yet no licensed broadly protective vaccine against ETEC. One promising vaccine development strategy is to target strains expressing the heat-stable toxin (ST), particularly the human ST (STh), since infections with these strains are among the leading causes of diarrhea in children in low-and-middle income countries. A human challenge model based on an STh-only ETEC strain will be useful to evaluate the protective efficacy of new ST-based vaccine candidates. To develop this model, we experimentally infected 21 healthy adult volunteers with the epidemiologically relevant STh-only ETEC strain TW10722, identified a suitable dose, assessed safety, and characterized clinical outcomes and immune responses caused by the infection. Doses of 1×1010 colony-forming units (CFU) of TW10722 gave a suitable attack risk of 67% for moderate or severe diarrhea and an overall diarrhea attack risk of 78%. Non-diarrheal symptoms were mostly mild or moderate, and there were no serious adverse events. During the first month after ingesting the challenge strain, we measured significant increases in both activated CD4+ T cells and levels of serum IgG and IgA antibodies targeting coli surface antigen 5 (CS5) and 6 (CS6), as well as the E. coli mucinase YghJ. The CS5-specific CD4+ T cell and antibody responses were still significantly elevated one year after experimental infection. In conclusion, we have developed a safe STh-only ETEC-based human challenge model which can be efficiently used in Phase 2B trials to evaluate the protective efficacy of new ST-based vaccine candidates. Enterotoxigenic Escherichia coli (ETEC) is a common cause of diarrheal illness in young children living in low- and middle-income countries and in travelers to these countries. Several ETEC vaccine candidates are currently being developed, but so far, no broadly protective vaccines have been licensed. Since most moderate and severe ETEC diarrheal episodes are caused by strains that express the heat-stable enterotoxin (ST), ST represents a promising vaccine target. Here we present a human challenge model that can be used to estimate the protective efficacy of ST-based vaccine candidates in clinical vaccine trials. The model is based on the epidemiologically relevant ST-only ETEC strain TW10722, which we show is safe to ingest by volunteers and readily induce diarrhea.
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A Review of Guidelines/Guidance from Various Countries Around the World for the Prevention and Management of Travellers' Diarrhoea: A Pharmacist's Perspective. PHARMACY 2019; 7:pharmacy7030107. [PMID: 31382691 PMCID: PMC6789525 DOI: 10.3390/pharmacy7030107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/20/2019] [Accepted: 07/23/2019] [Indexed: 01/23/2023] Open
Abstract
International travel is growing and pharmacists are well placed to provide travel health services for the prevention and management of travellers’ diarrhoea (TD). Legislation changes in many countries has enabled pharmacists to access prescription only medicines and vaccinations to provide advice and over the counter medicines for the prevention and management for travel health services; this makes sense since pharmacies are easily accessible to the public and are the patient’s first port of call in the event of any illness. Currently, whilst many guidelines/guidance exist worldwide for the prevention and management of TD, there is no review that focuses on similarities and differences between these and between guidelines on TD and travel related and non-travel related acute diarrhoea. There is also a lack of publication on legislation and the need for evidence based training for all prescribers to provide travel health services. The aims of this work were to review guidelines/guidance for the prevention and management of TD from across the world which were compared with each other as were the TD guidelines compared to that for travel related and non-travel related acute diarrhoea for similarities and differences, with a focus on any relevant pharmacy legislation, needs assessments and training that may impact upon provision of travel health services by pharmacists focusing mainly on TD in adults. The PubMed, Google Scholar and Cochrane database were used to carry out an online search for publications on TD, acute diarrhoea and the guidance pharmacists have in the prevention and management of diarrhoea. The literature reviewed in this article indicates that where no specific guidelines/guidance existed, some pharmacists used the WHO guidelines (WHO), highlighting a need for local, regional and national evidence based guidelines in these countries.
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Abstract
PURPOSE OF REVIEW Review recent developments pertaining to the epidemiology, molecular pathogenesis, and sequelae of enterotoxigenic Escherichia coli (ETEC) infections in addition to discussion of challenges for vaccinology. RECENT FINDINGS ETEC are a major cause of diarrheal illness in resource poor areas of the world where they contribute to unacceptable morbidity and continued mortality particularly among young children; yet, precise epidemiologic estimates of their contribution to death and chronic disease have been difficult to obtain. Although most pathogenesis studies, and consequently vaccine development have focused intensively on canonical antigens, more recently identified molecules unique to the ETEC pathovar may inform our understanding of ETEC virulence, and the approach to broadly protective vaccines. ETEC undeniably continue to have a substantial impact on global health; however, further studies are needed to clarify the true impact of these infections, particularly in regions where access to care may be limited. Likewise, our present understanding of the relationship of ETEC infection to non-diarrheal sequelae is presently limited, and additional effort will be required to achieve a mechanistic understanding of these diseases and to fulfill Koch's postulates on a molecular level. Precise elucidation of the role played by novel virulence factors, the global burden of acute illness, and the contribution of these pathogens and/or their toxins to non-diarrheal morbidity remain important imperatives.
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Affiliation(s)
- James M Fleckenstein
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, 660 South Euclid Avenue, Saint Louis, MO, 63110, USA.
- Medicine Service, Veterans Affairs Medical Center, Saint Louis, MO, USA.
| | - F Matthew Kuhlmann
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, 660 South Euclid Avenue, Saint Louis, MO, 63110, USA
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Epidemiology and etiology of diarrhea in UK military personnel serving on the United Nations Mission in South Sudan in 2017: A prospective cohort study. Travel Med Infect Dis 2019; 28:34-40. [DOI: 10.1016/j.tmaid.2018.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 12/10/2018] [Accepted: 12/11/2018] [Indexed: 02/07/2023]
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Guiral E, Gonçalves Quiles M, Muñoz L, Moreno-Morales J, Alejo-Cancho I, Salvador P, Alvarez-Martinez MJ, Marco F, Vila J. Emergence of Resistance to Quinolones and β-Lactam Antibiotics in Enteroaggregative and Enterotoxigenic Escherichia coli Causing Traveler's Diarrhea. Antimicrob Agents Chemother 2019; 63:e01745-18. [PMID: 30478165 PMCID: PMC6355616 DOI: 10.1128/aac.01745-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/16/2018] [Indexed: 12/15/2022] Open
Abstract
The objective of this study was to assess the antimicrobial resistance of enteroaggregative Escherichia coli (EAEC) and enterotoxigenic E. coli (ETEC) strains causing traveler's diarrhea (TD) and to investigate the molecular characterization of antimicrobial resistance genes to third-generation cephalosporins, cephamycins, and quinolones. Overall, 39 EAEC and 43 ETEC clinical isolates were studied. The susceptibilities of EAEC and ETEC against ampicillin, amoxicillin-clavulanic acid, cefotaxime, imipenem, chloramphenicol, tetracycline, co-trimoxazole, nalidixic acid, ciprofloxacin, azithromycin, and rifaximin were determined. All genes encoding resistance determinants were detected by PCR or PCR plus DNA sequencing. The epidemiology of selected EAEC and ETEC strains was studied using multilocus sequence typing (MLST). The resistance to quinolones of EAEC and ETEC strains causing TD has significantly increased over the last decades, and high percentages have been found especially in patients traveling to India and sub-Saharan Africa. Sequence type 38 (ST38) and ST131, carrying the blaCTX-M-15 and blaCTX-M-27 genes, respectively, are highly prevalent among extended-spectrum β-lactamase (ESBL)-producing EAEC and ETEC strains. The cephamycinase ACT-20 is described in the present study for the first time in EAEC and ETEC strains causing TD in patients who had traveled to Central America. The percentages of resistance to azithromycin in EAEC and ETEC isolates from patients to Southeast Asia/India and Africa are above 25%. Meanwhile, rifaximin is still active against EAEC and ETEC, with the prevalence of resistant strains not being high. In conclusion, fluoroquinolones should no longer be considered the drugs of choice for the prevention or treatment in TD for travelers traveling to India and Africa. Azithromycin and rifaximin are still a good alternative to treat TD caused by EAEC or ETEC.
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Affiliation(s)
| | | | - Laura Muñoz
- Institute of Global Health of Barcelona, Barcelona, Spain
| | | | - Izaskun Alejo-Cancho
- Department of Clinical Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Pilar Salvador
- Department of Clinical Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Miriam J Alvarez-Martinez
- Institute of Global Health of Barcelona, Barcelona, Spain
- Department of Clinical Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Francesc Marco
- Institute of Global Health of Barcelona, Barcelona, Spain
- Department of Clinical Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, Barcelona, Spain
| | - Jordi Vila
- Institute of Global Health of Barcelona, Barcelona, Spain
- Department of Clinical Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, Barcelona, Spain
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Suryapranata F, Boyd A, Grobusch MP, Prins M, Sonder G. Symptoms of infectious diseases in HIV-positive travellers: A prospective study with exposure-matched controls. Travel Med Infect Dis 2019; 29:28-33. [PMID: 30641130 DOI: 10.1016/j.tmaid.2019.01.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 01/06/2019] [Accepted: 01/07/2019] [Indexed: 01/07/2023]
Abstract
BACKGROUND Recently, the number of HIV-infected travellers to (sub)tropical areas has increased substantially. In the Netherlands, HIV-positive travellers with CD4-cells of <500/mm3 are advised to carry stand-by antibiotic treatment against travellers' diarrhoea. Our aim was to determine whether HIV infection is associated with travel-related symptomatic diseases. METHODS A prospective study was performed among HIV-infected travellers and age-matched HIV-uninfected travel companions serving as controls, attending two travel clinics in Amsterdam. Participants filled out daily questionnaires before, during, and after their trip. RESULTS Overall, 52 pairs were included. All participants were male, and 91.3% were born in a Western country. Prevalence of travel-related diarrhoea was 50% among HIV-positive travellers and 40% among controls. No significant differences were observed for incident travel-related diarrhoea (incidence rate ratio = 1.60, 95%CI = 0.79-3.27) or duration of symptoms (odds ratio = 1.49, 95%CI = 0.65-3.45). There were no significant differences in symptom incidence or duration for travel-related vomiting, cough, rhinitis, pruritus, fatigue, or nausea. Only 6.3% of HIV-positive travellers with CD4-cells of <500/mm3 and diarrhoea used their stand-by antibiotic treatment as recommended. CONCLUSION Travel-related symptoms were not significantly more frequent or longer lasting among HIV-infected travellers compared to controls. Most HIV-infected travellers with CD4-cells of <500/mm3 and diarrhoea did not take stand-by antibiotic treatment. These results may question the need for routine prescription of stand-by antibiotics among this specific risk group. Further research, especially among HIV infected VFR travellers and in larger study groups is needed.
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Affiliation(s)
- Franciska Suryapranata
- Department of Infectious Diseases, Public Health Service (GGD) of Amsterdam, Amsterdam, the Netherlands; National Coordination Centre for Travellers' Health Advice (LCR), Amsterdam, the Netherlands.
| | - Anders Boyd
- Department of Infectious Diseases, Public Health Service (GGD) of Amsterdam, Amsterdam, the Netherlands; INSERM, UMR S1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France
| | - Martin P Grobusch
- Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center, Amsterdam Infection & Immunity Institute (AIII), University of Amsterdam, the Netherlands
| | - Maria Prins
- Department of Infectious Diseases, Public Health Service (GGD) of Amsterdam, Amsterdam, the Netherlands; Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center, Amsterdam Infection & Immunity Institute (AIII), University of Amsterdam, the Netherlands
| | - Gerard Sonder
- Department of Infectious Diseases, Public Health Service (GGD) of Amsterdam, Amsterdam, the Netherlands; National Coordination Centre for Travellers' Health Advice (LCR), Amsterdam, the Netherlands; Department of Infectious Diseases, Division of Internal Medicine, Academic Medical Center, Amsterdam Infection & Immunity Institute (AIII), University of Amsterdam, the Netherlands
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Heat-Stable Enterotoxins of Enterotoxigenic Escherichia coli and Their Impact on Host Immunity. Toxins (Basel) 2019; 11:toxins11010024. [PMID: 30626031 PMCID: PMC6356903 DOI: 10.3390/toxins11010024] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/31/2018] [Accepted: 01/03/2019] [Indexed: 01/12/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) are an important diarrhea-causing pathogen and are regarded as a global threat for humans and farm animals. ETEC possess several virulence factors to infect its host, including colonization factors and enterotoxins. Production of heat-stable enterotoxins (STs) by most ETEC plays an essential role in triggering diarrhea and ETEC pathogenesis. In this review, we summarize the heat-stable enterotoxins of ETEC strains from different species as well as the molecular mechanisms used by these heat-stable enterotoxins to trigger diarrhea. As recently described, intestinal epithelial cells are important modulators of the intestinal immune system. Thus, we also discuss the impact of the heat-stable enterotoxins on this role of the intestinal epithelium and how these enterotoxins might affect intestinal immune cells. Finally, the latest developments in vaccination strategies to protect against infections with ST secreting ETEC strains are discussed. This review might inform and guide future research on heat-stable enterotoxins to further unravel their molecular pathogenesis, as well as to accelerate vaccine design.
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Leung AK, Leung AA, Wong AH, Hon KL. Travelers' Diarrhea: A Clinical Review. RECENT PATENTS ON INFLAMMATION & ALLERGY DRUG DISCOVERY 2019; 13:38-48. [PMID: 31084597 PMCID: PMC6751351 DOI: 10.2174/1872213x13666190514105054] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 04/30/2019] [Accepted: 05/10/2019] [Indexed: 02/08/2023]
Abstract
BACKGROUND Travelers' diarrhea is the most common travel-related malady. It affects millions of international travelers to developing countries annually and can significantly disrupt travel plans. OBJECTIVE To provide an update on the evaluation, diagnosis, treatment, and prevention of traveler's diarrhea. METHODS A PubMed search was completed in Clinical Queries using the key term "traveler's diarrhea". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. Patents were searched using the key term "traveler's diarrhea" from www.freepatentsonline.com. RESULTS Between 10% and 40% of travelers develop diarrhea. The attack rate is highest for travelers from a developed country who visit a developing country. Children are at particular risk. Travelers' diarrhea is usually acquired through ingestion of food and water contaminated by feces. Most cases are due to a bacterial pathogen, commonly, Escherichia coli, and occur within the first few days after arrival in a foreign country. Dehydration is the most common complication. Pretravel education on hygiene and on the safe selection of food items is important in minimizing episodes. For mild travelers' diarrhea, the use of antibiotic is not recommended. The use of bismuth subsalicylate or loperamide may be considered. For moderate travelers' diarrhea, antibiotics such as fluoroquinolones, azithromycin, and rifaximin may be used. Loperamide may be considered as monotherapy or adjunctive therapy. For severe travelers' diarrhea, antibiotics such as azithromycin, fluoroquinolones, and rifaximin should be used. Azithromycin can be used even for the treatment of dysentery whereas fluoroquinolones and rifaximin cannot be used for such purpose. Recent patents related to the management of travelers' diarrhea are discussed. CONCLUSION Although travelers' diarrhea is usually self-limited, many travelers prefer expedient relief of diarrhea, especially when they are traveling for extended periods by air or ground. Judicious use of an antimotility agent and antimicrobial therapy reduces the duration and severity of diarrhea.
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Affiliation(s)
- Alexander K.C. Leung
- Address correspondence to this author at the University of Calgary, Alberta Children’s Hospital, #200, 233 - 16th Avenue NW, Calgary, Alberta, Canada T2M 0H5; Tel: (403) 230 3300; Fax: (403) 230 3322; E-mail:
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Lindsay L, DuPont HL, Moe CL, Alberer M, Hatz C, Kirby AE, Wu HM, Verstraeten T, Steffen R. Estimating the incidence of norovirus acute gastroenteritis among US and European international travelers to areas of moderate to high risk of traveler's diarrhea: a prospective cohort study protocol. BMC Infect Dis 2018; 18:605. [PMID: 30509202 PMCID: PMC6276235 DOI: 10.1186/s12879-018-3461-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 10/31/2018] [Indexed: 12/31/2022] Open
Abstract
Background Acute gastroenteritis (AGE) is the leading cause of illness among returning travelers seeking medical care. Multiple types of enteric pathogens can cause travel-acquired AGE and, while bacterial pathogens have a predominant role, the importance of viruses, such as norovirus, is increasingly recognized. There is a lack of information on travel-acquired norovirus incidence among symptomatic and asymptomatic individuals irrespective of healthcare-seeking behavior. Our aim is to estimate the incidence of travel-acquired AGE due to norovirus and to characterize the burden of disease among international travelers from the United States and Europe. Methods We describe a prospective cohort study implemented in five US and European sites to estimate the role of AGE due to norovirus among adult international travelers. We enrolled individuals aged 18 years and older who are traveling to regions of moderate-high risk of AGE, or via cruise ship with an international port stop, with a trip duration of 3–15 days. The study will generate a wide range of health and travel-related data for pre-, during, and up to 6-months post-travel. We will identify laboratory-confirmed travel-acquired norovirus infections among both symptomatic and asymptomatic individuals from self-collected whole stool samples tested via quantitative RT-PCR. Coinfections will be identified in a subset of travelers with AGE using a multiplex molecular-based assay. Discussion This study is unique in design and breadth of data collected. The prospective collection of health and behavioral data, as well as biologic samples from travelers irrespective of symptoms, will provide useful data to better understand the importance of norovirus AGE among international travelers. This study will provide data to estimate the incidence of norovirus infections and AGE and the risk of post-infectious sequelae in the 6-month post-travel period serving as a baseline for future norovirus AGE vaccination studies. This study will contribute valuable information to better understand the role of norovirus in travel-acquired AGE risk and the impact of these infections on a broad set of outcomes.
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Affiliation(s)
- Lisa Lindsay
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III Laan 1, 3001, Leuven, Belgium.
| | - Herbert L DuPont
- University of Texas McGovern Medical School and School of Public Health, 1200 Pressler Street, Houston, TX, 77030, USA
| | - Christine L Moe
- Emory University, Rollins School of Public Health, 1518 Clifton Road NE, Atlanta, GA, 30322, USA
| | - Martin Alberer
- Division of Infectious Diseases and Tropical Medicine, University Hospital, Ludwig-Maximilians-University (LMU) Munich, Leopoldstrasse 5, 80802, Munich, Germany
| | - Christoph Hatz
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4056, Basel, Switzerland.,University of Basel, Petersplatz 1, 4001, Basel, Switzerland.,University of Zurich; Epidemiology, Biostatistics and Prevention Institute, WHO Collaborating Centre for Travellers' Health, Hirschengraben 84, 8001, Zurich, Switzerland
| | - Amy E Kirby
- Emory University, Rollins School of Public Health, 1518 Clifton Road NE, Atlanta, GA, 30322, USA
| | - Henry M Wu
- Emory University, Division of Infectious Diseases, Department of Medicine, 550 Peachtree Street NE MOT 7, Atlanta, GA, 30308, USA
| | - Thomas Verstraeten
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III Laan 1, 3001, Leuven, Belgium
| | - Robert Steffen
- University of Texas McGovern Medical School and School of Public Health, 1200 Pressler Street, Houston, TX, 77030, USA.,University of Zurich; Epidemiology, Biostatistics and Prevention Institute, WHO Collaborating Centre for Travellers' Health, Hirschengraben 84, 8001, Zurich, Switzerland
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Huang J, Duan Q, Zhang W. Significance of Enterotoxigenic Escherichia coli (ETEC) Heat-Labile Toxin (LT) Enzymatic Subunit Epitopes in LT Enterotoxicity and Immunogenicity. Appl Environ Microbiol 2018; 84:e00849-18. [PMID: 29802193 PMCID: PMC6052278 DOI: 10.1128/aem.00849-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/19/2018] [Indexed: 01/28/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains producing heat-labile toxin (LT) and/or heat-stable toxin (STa) are a top cause of children's diarrhea and travelers' diarrhea. Holotoxin-structured GM1-binding LT is a strong immunogen and an effective adjuvant, and can serve a carrier or a platform for multivalent vaccine development. However, the significance of peptide domains or epitopes of LT particularly enzymatic LTA subunit in association with LT enterotoxicity and immunogenicity has not been characterized. In this study, we identified B-cell epitopes in silico from LTA subunit and examined epitopes for immunogenicity and association with LT enterotoxicity. Epitopes identified from LTA subunit were individually fused to a modified chicken ovalbumin carrier protein, and each epitope-ovalbumin fusion was used to immunize mice. Data showed all 11 LTA epitopes were immunogenic; epitope 7 (105SPHPYEQEVSA115) induced greater titers of anti-LT antibodies which neutralized LT enterotoxicity more effectively. To examine these epitopes for the significance in LT enterotoxicity, we constructed LT mutants by substituting each of 10 epitopes at the toxic A1 domain of LTA subunit with a foreign epitope and examined LT mutants for enterotoxicity and GM1-binding activity. Data showed that LT mutants exhibited no enterotoxicity but retained GM1-binding activity. The results from this study indicated that while not all immunodominant LTA epitopes were neutralizing, LT mutants with an individual epitope substituted lost enterotoxicity but retained GM1-binding activity. These results provided additional information to understand LT immunogenicity and enterotoxicity and suggested the potential application of LT platform for multivalent vaccines against ETEC diarrhea and other diseases.IMPORTANCE No vaccine is licensed for enterotoxigenic Escherichia coli (ETEC) strains, which remain a leading cause of diarrhea in children from developing countries and international travelers. GM1-binding heat-labile toxin (LT) which is a key virulence factor of ETEC diarrhea is a strong vaccine antigen and a self-adjuvant. LT can also serve a backbone or platform for MEFA (multiepitope fusion antigen), a newly developed structural vaccinology technology, to present heterogeneous epitopes (by replacing LT epitopes) and to mimic epitope antigenicity for development of broadly protective vaccines. Data from this study identified neutralizing LT epitopes and demonstrated that substitution of LT epitopes eliminated LT enterotoxicity without altering GM1-binding activity, suggesting LT is potentially a versatile MEFA platform to present heterogeneous epitopes for multivalent vaccines against ETEC and other pathogens.
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Affiliation(s)
- Jiachen Huang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| | - Qiangde Duan
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
| | - Weiping Zhang
- Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA
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Williams E, Lew TE, Fuller A, Spelman DW, Jenney AW. A case of multi-drug resistant ESBL-producing Shigella sonnei acute acalculous cholecystitis and gastroenteritis in a returned traveller. J Travel Med 2018; 25:5088401. [PMID: 30169854 DOI: 10.1093/jtm/tay029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 07/23/2018] [Indexed: 01/13/2023]
Abstract
The first case of Shigella-associated acalculous cholecystitis is described. A 27-year-old woman presented to hospital with diarrhoea and acute acalculous cholecystitis one day after return to Australia from Vietnam. Her feces culture grew multi-drug resistant ESBL-producing Shigella sonnei and she improved with antimicrobial therapy and intravenous fluids.
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Affiliation(s)
- Eloise Williams
- Alfred Health, Melbourne, Victoria, Australia.,Monash University, Melbourne, Victoria, Australia
| | | | - Andrew Fuller
- Alfred Health, Melbourne, Victoria, Australia.,Monash University, Melbourne, Victoria, Australia
| | - Denis W Spelman
- Alfred Health, Melbourne, Victoria, Australia.,Monash University, Melbourne, Victoria, Australia
| | - Adam W Jenney
- Alfred Health, Melbourne, Victoria, Australia.,Monash University, Melbourne, Victoria, Australia
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Critical Role of Zinc in a New Murine Model of Enterotoxigenic Escherichia coli Diarrhea. Infect Immun 2018; 86:IAI.00183-18. [PMID: 29661930 PMCID: PMC6013668 DOI: 10.1128/iai.00183-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 04/11/2018] [Indexed: 12/11/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major cause of traveler's diarrhea as well as of endemic diarrhea and stunting in children in developing areas. However, a small-mammal model has been badly needed to better understand and assess mechanisms, vaccines, and interventions. We report a murine model of ETEC diarrhea, weight loss, and enteropathy and investigate the role of zinc in the outcomes. ETEC strains producing heat-labile toxins (LT) and heat-stable toxins (ST) that were given to weaned C57BL/6 mice after antibiotic disruption of normal microbiota caused growth impairment, watery diarrhea, heavy stool shedding, and mild to moderate intestinal inflammation, the latter being worse with zinc deficiency. Zinc treatment promoted growth in zinc-deficient infected mice, and subinhibitory levels of zinc reduced expression of ETEC virulence genes cfa1, cexE, sta2, and degP but not of eltA in vitro Zinc supplementation increased shedding and the ileal burden of wild-type (WT) ETEC but decreased shedding and the tissue burden of LT knockout (LTKO) ETEC. LTKO ETEC-infected mice had delayed disease onset and also had less inflammation by fecal myeloperoxidase (MPO) assessment. These findings provide a new murine model of ETEC infection that can help elucidate mechanisms of growth, diarrhea, and inflammatory responses as well as potential vaccines and interventions.
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47
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Learoyd TP, Gaut RM. Cholera: under diagnosis and differentiation from other diarrhoeal diseases. J Travel Med 2018; 25:S46-S51. [PMID: 29718439 DOI: 10.1093/jtm/tay017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 02/08/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND Globally 1.4 billion people are at risk from cholera in countries where the disease is endemic, with an estimated 2.8 million cases annually. The disease is significantly under reported due to economic, social and political disincentives as well as poor laboratory resources and epidemiological surveillance in those regions. In addition, identification of cholera from other diarrhoeal causes is often difficult due to shared pathology and symptoms with few reported cases in travellers from Northern Europe. METHODS A search of PubMed and Ovid Medline for publications on cholera diagnosis from 2010 through 2017 was conducted. Search terms included were cholera, Rapid Diagnostic Test (RDT), multiplex PCR and diagnosis of diarrhoea. Studies were included if they are published in English, French or Spanish. RESULTS An increase of RDT study publications for diarrhoeal disease and attempted test validations were seen over the publication period. RDTs were noted as having varied selectivity and specificity, as well as associated costs and local resource requirements that can prohibit their use. CONCLUSIONS Despite opportunities to employ RDTs with high selectivity and specificity in epidemic areas, or in remote locations without access to health services, such tests are limited to surveillance use. This may represent a missed opportunity to discover the true global presence of Vibrio cholerae and its role in all cause diarrhoeal disease in underdeveloped countries and in travellers to those areas. The wider applicability of RDTs may also represent an opportunity in the wider management of traveller's diarrhoea.
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Affiliation(s)
- Tristan P Learoyd
- Valneva UK, Centaur House, Ancells Business Park, Ancells Road, Fleet, Hampshire GU51 2UJ, UK
| | - Rupert M Gaut
- Xnomics Ltd, Yarm Road, Eaglescliffe, Stockton-on-Tees TS16 9BJ, UK
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48
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Neutralizing Anti-Heat-Stable Toxin (STa) Antibodies Derived from Enterotoxigenic Escherichia coli Toxoid Fusions with STa Proteins Containing N12S, L9A/N12S, or N12S/A14T Mutations Show Little Cross-Reactivity with Guanylin or Uroguanylin. Appl Environ Microbiol 2018; 84:AEM.01737-17. [PMID: 29079628 DOI: 10.1128/aem.01737-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/19/2017] [Indexed: 11/20/2022] Open
Abstract
Heat-stable toxin (STa)-producing enterotoxigenic Escherichia coli (ETEC) strains are a top cause of moderate-to-severe diarrhea in children from developing countries and a common cause of travelers' diarrhea. Recent progress in using STa toxoids and toxoid fusions to induce neutralizing anti-STa antibodies has accelerated ETEC vaccine development. However, concern remains regarding whether the derived anti-STa antibodies cross-react with STa-like guanylin and uroguanylin, two guanylate cyclase C (GC-C) ligands regulating fluid and electrolyte transportation in human intestinal and renal epithelial cells. To further divert STa from guanylin and uroguanylin structurally and antigenically and to eliminate anti-STa antibody cross-reactivity with guanylin and uroguanylin, we mutated STa at the 9th (leucine), 12th (asparagine), and 14th (alanine) residues for the double and triple mutants STaL9A/N12S, STaL9A/A14H, STaN12S/A14T, and STaL9A/N12S/A14H We then fused each STa mutant (three copies) to a monomeric heat-labile toxin (LT) mutant (mnLTR192G/L211A) for the toxoid fusions 3×STaL9A/N12S-mnLTR192G/L211A, 3×STaL9A/A14H-mnLTR192G/L211A, 3×STaN12S/A14T-mnLTR192G/L211A, and 3×STaL9A/N12S/A14H-mnLTR192G/L211A; examined each fusion for anti-STa immunogenicity; and assessed the derived antibodies for in vitro neutralization activity against STa toxicity and for cross-reactivity with guanylin and uroguanylin. Mice subcutaneously immunized with each fusion protein developed anti-STa antibodies, and the antibodies derived from 3×STaN12S-mnLTR192G/L211A, 3×STaL9A/N12S-mnLTR192G/L211A, or 3×STaN12S/A14T-mnLTR192G/L211A prevented STa from the stimulation of intracellular cGMP in T-84 cells. Competitive enzyme-linked immunosorbent assays (ELISAs) showed that guanylin and uroguanylin hardly blocked the binding of anti-STa antibodies to the coated STa-ovalbumin conjugate. These results indicated that antibodies derived from 3×STaN12S-mnLTR192G/L211A, 3×STaL9A/N12S-mnLTR192G/L211A, or 3×STaN12S/A14T-mnLTR192G/L211A neutralized STa and had little cross-reactivity with guanylin and uroguanylin, suggesting that these toxoid fusions are suitable antigens for ETEC vaccines.IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) strains are a leading cause of children's diarrhea and travelers' diarrhea. Currently, there is no licensed vaccine against ETEC diarrhea. One key challenge is to identify safe antigens to induce antibodies neutralizing the key STa without cross-reacting with guanylin and uroguanylin, two important ligands controlling homeostasis in human intestinal and renal epithelial cells. In this study, we generated nontoxic fusion antigens that induced antibodies that neutralize STa enterotoxicity in vitro and do not cross-react with guanylin or uroguanylin. These fusions have become the preferred antigens for the development of ETEC vaccines to potentially prevent the deaths of hundreds of thousands of young children and hundreds of millions of diarrheal cases each year.
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Begum YA, Rydberg HA, Thorell K, Kwak YK, Sun L, Joffré E, Qadri F, Sjöling Å. In Situ Analyses Directly in Diarrheal Stool Reveal Large Variations in Bacterial Load and Active Toxin Expression of Enterotoxigenic Escherichiacoli and Vibrio cholerae. mSphere 2018; 3:e00517-17. [PMID: 29404412 PMCID: PMC5784243 DOI: 10.1128/msphere.00517-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/27/2017] [Indexed: 11/20/2022] Open
Abstract
The bacterial pathogens enterotoxigenic Escherichia coli (ETEC) and Vibrio cholerae are major causes of diarrhea. ETEC causes diarrhea by production of the heat-labile toxin (LT) and heat-stable toxins (STh and STp), while V. cholerae produces cholera toxin (CT). In this study, we determined the occurrence and bacterial doses of the two pathogens and their respective toxin expression levels directly in liquid diarrheal stools of patients in Dhaka, Bangladesh. By quantitative culture and real-time quantitative PCR (qPCR) detection of the toxin genes, the two pathogens were found to coexist in several of the patients, at concentrations between 102 and 108 bacterial gene copies per ml. Even in culture-negative samples, gene copy numbers of 102 to 104 of either ETEC or V. cholerae toxin genes were detected by qPCR. RNA was extracted directly from stool, and gene expression levels, quantified by reverse transcriptase qPCR (RT-qPCR), of the genes encoding CT, LT, STh, and STp showed expression of toxin genes. Toxin enzyme-linked immunosorbent assay (ELISA) confirmed active toxin secretion directly in the liquid diarrhea. Analysis of ETEC isolates by multiplex PCR, dot blot analysis, and genome sequencing suggested that there are genetic ETEC profiles that are more commonly found as dominating single pathogens and others that are coinfectants with lower bacterial loads. The ETEC genomes, including assembled genomes of dominating ETEC isolates expressing LT/STh/CS5/CS6 and LT/CS7, are provided. In addition, this study highlights an emerging important ETEC strain expressing LT/STp and the novel colonization factor CS27b. These findings have implications for investigations of pathogenesis as well as for vaccine development. IMPORTANCE The cause of diarrheal disease is usually determined by screening for several microorganisms by various methods, and sole detection is used to assign the agent as the cause of disease. However, it has become increasingly clear that many infections are caused by coinfections with several pathogens and that the dose of the infecting pathogen is important. We quantified the absolute numbers of enterotoxigenic E. coli (ETEC) and Vibrio cholerae directly in diarrheal fluid. We noted several events where both pathogens were found but also a large dose dependency. In three samples, we found ETEC as the only pathogen sought for. These isolates belonged to globally distributed ETEC clones and were the dominating species in stool with active toxin expression. This suggests that certain superior virulent ETEC lineages are able to outcompete the gut microbiota and be the sole cause of disease and hence need to be specifically monitored.
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Affiliation(s)
- Yasmin Ara Begum
- International Centre for Diarrhoeal Disease Research, Bangladesh, Centre for Health and Population Research, Dhaka, Bangladesh
| | - Hanna A. Rydberg
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research (CTMR), Karolinska Institutet, Stockholm, Sweden
| | - Kaisa Thorell
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research (CTMR), Karolinska Institutet, Stockholm, Sweden
| | - Young-Keun Kwak
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research (CTMR), Karolinska Institutet, Stockholm, Sweden
| | - Lei Sun
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research (CTMR), Karolinska Institutet, Stockholm, Sweden
| | - Enrique Joffré
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research (CTMR), Karolinska Institutet, Stockholm, Sweden
| | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Bangladesh, Centre for Health and Population Research, Dhaka, Bangladesh
| | - Åsa Sjöling
- Department of Microbiology, Tumor and Cell Biology, Centre for Translational Microbiome Research (CTMR), Karolinska Institutet, Stockholm, Sweden
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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50
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Hamer DH. Multiplex PCR for determining aetiology of travellers' diarrhoea: too much information or too little? J Travel Med 2018; 25:4780171. [PMID: 29394386 DOI: 10.1093/jtm/tax089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 11/19/2017] [Indexed: 11/14/2022]
Affiliation(s)
- Davidson H Hamer
- Department of Global Health and Center for Global Health and Development, Boston University School of Public Health, Boston, MA, USA
- Section of Infectious Diseases, Department of Medicine, Boston Medical Center, Boston, MA, USA
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