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Batool R, Qureshi S, Haq Z, Yousafzai MT, Salam RA, Ali R, Sadaf T, Ali M, Qamar FN. Coverage survey of typhoid conjugate vaccine among children aged 6 months to 15 years in an urban slum settlement of Lyari Town Karachi, Pakistan. PLoS One 2023; 18:e0289582. [PMID: 37549155 PMCID: PMC10406246 DOI: 10.1371/journal.pone.0289582] [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: 07/13/2021] [Accepted: 07/24/2023] [Indexed: 08/09/2023] Open
Abstract
OBJECTIVE To estimate the coverage rate of typhoid conjugate vaccine (TCV) among children aged 6 months to 15 years in Lyari Town Karachi, Pakistan. METHODS A cross-sectional survey was conducted to estimate the vaccine coverage of Typbar TCV in Lyari Town Karachi utilizing the World Health Organization (WHO) recommended rapid vaccine coverage assessment technique (30 clusters × 7 households). Sampling was powered at town level and multistage cluster sampling was used. Four union councils were randomly selected from a total of 11 and the survey was conducted in those union councils. After consent was obtained, parents of age-eligible children living in the selected union councils were invited to participate in the survey and information was collected on Typbar TCV vaccination status of children aged 6 months to 15 years. RESULTS Overall, 2325 children were included in the survey. The mean age of the participants was 7.60 ± 3.84 years. The ratio of males to females was equal in the survey sample; 1163 (50.02%) were male. In the total target population, 82% children were found to be vaccinated; however, the vaccination status could be verified for 80%. The vaccine coverage of TCV was comparable among the four union councils and the overall coverage of TCV vaccine in Lyari Town was found to be 80%. The coverage was significantly lower in younger children, 5% and 17% among children aged 6 months to < 2 years and 2 years to < 5 years respectively and 78% among children aged 5 years to 15 years. CONCLUSION The overall immunization coverage rate with TCV was found to be satisfactory. Immunization coverage was comparable among both sexes and the selected union councils but it was relatively low among children in younger age groups.
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Affiliation(s)
- Rabab Batool
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan
- Center for Child, Adolescent, and Maternal Health, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Sonia Qureshi
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan
| | - Zoya Haq
- Liaqat National Hospital, Karachi, Pakistan
| | - Mohammad Tahir Yousafzai
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan
- Kirby Institute, University of New South Wales, Sydney, NSW, Australia
| | - Rehana A. Salam
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan
| | - Rafey Ali
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan
| | - Tahira Sadaf
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan
| | - Miqdad Ali
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan
| | - Farah Naz Qamar
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Karachi, Pakistan
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Identification of collaborative cross mouse strains permissive to Salmonella enterica serovar Typhi infection. Sci Rep 2023; 13:393. [PMID: 36624251 PMCID: PMC9829673 DOI: 10.1038/s41598-023-27400-1] [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: 10/01/2022] [Accepted: 01/02/2023] [Indexed: 01/11/2023] Open
Abstract
Salmonella enterica serovar Typhi is the causative agent of typhoid fever restricted to humans and does not replicate in commonly used inbred mice. Genetic variation in humans is far greater and more complex than that in a single inbred strain of mice. The Collaborative Cross (CC) is a large panel of recombinant inbred strains which has a wider range of genetic diversity than laboratory inbred mouse strains. We found that the CC003/Unc and CC053/Unc strains are permissive to intraperitoneal but not oral route of S. Typhi infection and show histopathological changes characteristic of human typhoid. These CC strains are immunocompetent, and immunization induces antigen-specific responses that can kill S. Typhi in vitro and control S. Typhi in vivo. Our results indicate that CC003/Unc and CC053/Unc strains can help identify the genetic basis for typhoid susceptibility, S. Typhi virulence mechanism(s) in vivo, and serve as a preclinical mammalian model system to identify effective vaccines and therapeutics strategies.
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Bahy R, Gaber A, Zedan H, Mabrook M. New typhoid vaccine using sponge-like reduced protocol: development and evaluation. Clin Exp Vaccine Res 2023; 12:70-76. [PMID: 36844684 PMCID: PMC9950223 DOI: 10.7774/cevr.2023.12.1.70] [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: 08/01/2022] [Accepted: 11/22/2022] [Indexed: 02/19/2023] Open
Abstract
Purpose Typhoid remains a major health problem, especially in the developing world. Furthermore, the emergence of multidrug-resistant and extensively drug-resistant strains of Salmonella typhi added a sense of urgency to develop more effective typhoid vaccines, one of which is bacterial ghosts (BGs), prepared by both genetic and chemical means. The chemical method includes incubation with numerous agents for a short time at their minimum inhibitory or minimum growth concentrations. This study included the preparation of BGs by a sponge-like reduced protocol (SLRP). Materials and Methods Critical concentrations of sodium dodecyl sulfate, NaOH, and H2O2 were used. Moreover, high-quality BGs were visualized by scanning electron microscope (SEM). Subculturing was used to confirm the absence of vital cells. Besides, the concentrations of the released DNA and protein were estimated spectrophotometrically. In addition, the integrity of cells was proved by visualizing Gram-stained cells using a light microscope. Furthermore, a comparison between the immunogenicity and safety of the prepared vaccine and the available whole-cell killed vaccine was established. Results Improved preparation of high-quality BGs of S. typhi, visualized by SEM, revealed punctured cells with intact outer shells. Moreover, the absence of vital cells was confirmed by subculturing. At the same time, the release of respective amounts of proteins and DNA is another evidence of BGs' production. Additionally, the challenge test provided evidence that the prepared BGs are immunogenic and have the same efficacy as the whole cell vaccine. Conclusion The SLRP provided a simple, economical, and feasible method for BGs preparation.
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Affiliation(s)
- Rehab Bahy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Fayoum University, Fayoum, Egypt
| | - Asmaa Gaber
- Department of Microbiology, General Division of Basic Medical Sciences, Egyptian Drug Authority (EDA), formerly National Organization for Drug Control and Research (NODCAR), Giza, Egypt
| | - Hamdallah Zedan
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Mona Mabrook
- Department of Microbiology, General Division of Basic Medical Sciences, Egyptian Drug Authority (EDA), formerly National Organization for Drug Control and Research (NODCAR), Giza, Egypt
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Alugupalli AS, Cravens MP, Walker JA, Gulandijany D, Dickinson GS, Debes GF, Schifferli DM, Bäumler AJ, Alugupalli KR, Alugupalli KR. The Lack of Natural IgM Increases Susceptibility and Impairs Anti-Vi Polysaccharide IgG Responses in a Mouse Model of Typhoid. Immunohorizons 2022; 6:807-816. [PMID: 36480484 DOI: 10.4049/immunohorizons.2200088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 12/13/2022] Open
Abstract
Circulating IgM present in the body prior to any apparent Ag exposure is referred to as natural IgM. Natural IgM provides protective immunity against a variety of pathogens. Salmonella enterica serovar Typhi (S. Typhi) is the causative agent of typhoid fever in humans. Because mice are not permissive to S. Typhi infection, we employed a murine model of typhoid using S. enterica serovar Typhimurium expressing the Vi polysaccharide (ViPS) of S. Typhi (S. Typhimurium strain RC60) to evaluate the role of natural IgM in pathogenesis. We found that natural mouse IgM binds to S. Typhi and S. Typhimurium. The severity of S. Typhimurium infection in mice is dependent on presence of the natural resistance-associated macrophage protein 1 (Nramp1) allele; therefore, we infected mice deficient in secreted form of IgM (sIgM) on either a Nramp1-resistant (129S) or -susceptible (C57BL/6J) background. We found that the lack of natural IgM results in a significantly increased susceptibility and an exaggerated liver pathology regardless of the route of infection or the Nramp1 allele. Reconstitution of sIgM-/- mice with normal mouse serum or purified polyclonal IgM restored the resistance to that of sIgM+/+ mice. Furthermore, immunization of sIgM-/- mice with heat-killed S. Typhi induced a significantly reduced anti-ViPS IgG and complement-dependent bactericidal activity against S. Typhi in vitro, compared with that of sIgM+/+ mice. These findings indicate that natural IgM is an important factor in reducing the typhoid severity and inducing an optimal anti-ViPS IgG response to vaccination.
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Affiliation(s)
- Akhil S Alugupalli
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA.,Department of Microbiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
| | - Matthew P Cravens
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
| | - Justin A Walker
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
| | - Dania Gulandijany
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
| | - Gregory S Dickinson
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
| | - Gudrun F Debes
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA
| | - Dieter M Schifferli
- Department of Microbiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
| | - Andreas J Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, CA; and
| | - Kishore R Alugupalli
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA.,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA
| | - Kishore R Alugupalli
- Department of Microbiology and Immunology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA.,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA
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Thuluva S, Paradkar V, Matur R, Turaga K, Gv SR. A multicenter, single-blind, randomized, phase-2/3 study to evaluate immunogenicity and safety of a single intramuscular dose of biological E's Vi-capsular polysaccharide-CRM 197 conjugate typhoid vaccine (TyphiBEV TM) in healthy infants, children, and adults in comparison with a licensed comparator. Hum Vaccin Immunother 2022; 18:2043103. [PMID: 35333702 PMCID: PMC9196756 DOI: 10.1080/21645515.2022.2043103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The current scenario of typhoid fever warrants early prevention with typhoid conjugate vaccines in susceptible populations to provide lifelong protection. We conducted a multicenter, single-blind, randomized, Phase 2/3 study to assess the immunogenicity and safety of Biological E’s Typhoid Vi-CRM197 conjugate vaccine (TyphiBEVTM) compared to Vi-TT conjugate vaccine manufactured by Bharat Biotech International Limited (Typbar-TCV; licensed comparator) in healthy infants, children, and adults from India. The study’s primary objective was to assess the non-inferiority of TyphiBEVTM in terms of the difference in the proportion of subjects seroconverted with a seroconversion threshold value of ≥2.0 µg/mL against Typbar-TCV. A total of 622 healthy subjects (311 each in both vaccine groups) were randomized and received the single dose of the study vaccine. The TyphiBEVTM group demonstrated noninferiority compared to the Typbar-TCV group at Day 42. The lower 2-sided 95% confidence interval limit of the group difference was −.34%, which met the non-inferiority criteria of ≥10.0%. The geometric mean concentration (24.79 µg/mL vs. 26.58 µg/mL) and proportion of subjects who achieved ≥4-fold increase in antiVi IgG antibody concentrations (96.95% vs. 97.64%) at Day 42 were comparable between the TyphiBEVTM and Typbar-TCV vaccine groups. No apparent difference was observed in the safety profile between both vaccine groups. All adverse events reported were mild or moderate in intensity in all age subsets. This data demonstrates that TyphiBEVTM is non-inferior to TypbarTCV in terms of immunogenicity, and the overall safety and reactogenicity in healthy infants, children, and adults studied from India was comparable.
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Affiliation(s)
- Subhash Thuluva
- Clinical Development Department, Biological E Limited, Hyderabad, India
| | - Vikram Paradkar
- Clinical Development Department, Biological E Limited, Hyderabad, India
| | - Ramesh Matur
- Clinical Development Department, Biological E Limited, Hyderabad, India
| | - Kishore Turaga
- Clinical Development Department, Biological E Limited, Hyderabad, India
| | - Subba Reddy Gv
- Clinical Development Department, Biological E Limited, Hyderabad, India
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Neupane DP, Ahn C, Yang YA, Lee GY, Song J. Malnutrition and maternal vaccination against typhoid toxin. PLoS Pathog 2022; 18:e1010731. [PMID: 35960787 PMCID: PMC9401117 DOI: 10.1371/journal.ppat.1010731] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 08/24/2022] [Accepted: 07/07/2022] [Indexed: 11/18/2022] Open
Abstract
Children are particularly susceptible to typhoid fever caused by the bacterial pathogen Salmonella Typhi. Typhoid fever is prevalent in developing countries where diets can be less well-balanced. Here, using a murine model, we investigated the role of the macronutrient composition of the diet in maternal vaccination efficacies of two subunit vaccines targeting typhoid toxin: ToxoidVac and PltBVac. We found that maternal vaccinations protected all offspring against a lethal-dose typhoid toxin challenge in a balanced, normal diet (ND) condition, but the declined protection in a malnourished diet (MD) condition was observed in the PltBVac group. Despite the comparable antibody titers in both MD and ND mothers, MD offspring had a significantly lower level of typhoid toxin neutralizing antibodies than their ND counterparts. We observed a lower expression of the neonatal Fc receptor on the yolk sac of MD mothers than in ND mothers, agreeing with the observed lower antibody titers in MD offspring. Protein supplementation to MD diets, but not fat supplementation, increased FcRn expression and protected all MD offspring from the toxin challenge. Similarly, providing additional typhoid toxin-neutralizing antibodies to MD offspring was sufficient to protect all MD offspring from the toxin challenge. These results emphasize the significance of balanced/normal diets for a more effective maternal vaccination transfer to their offspring. Typhoid fever is a life-threatening systemic infectious disease caused by Salmonella Typhi, which is prevalent in developing countries where diets can be less well-balanced. Here, we used mice to study the role of nutrition in maternal vaccination efficacies of two subunit vaccines targeting Salmonella’s typhoid toxin. We found maternal vaccinations protected all offspring from a lethal-dose typhoid toxin challenge in a balanced/normal diet (ND) condition, but the lack of protection in a malnourished diet (MD) condition was observed in the PltBVac group. Our data indicate that the difference in maternal vaccination outcomes between ND and MD offspring was due to the less effective maternal antibody transfer from MD mothers to their offspring. Providing additional proteins to MD mothers or additional toxin-neutralizing antibodies to MD offspring saved all malnourished offspring from a lethal-dose typhoid toxin challenge, highlighting the importance of balanced/normal diets for effective maternal vaccination outcomes.
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Affiliation(s)
- Durga P. Neupane
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York, United States of America
| | - Changhwan Ahn
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York, United States of America
| | - Yi-An Yang
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York, United States of America
| | - Gi Young Lee
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York, United States of America
| | - Jeongmin Song
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York, United States of America
- * E-mail:
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Abstract
AB toxins are protein virulence factors secreted by many bacterial pathogens, contributing to the pathogenicity of the cognate bacteria. AB toxins consist of two functionally distinct components: the enzymatic "A" component for pathogenicity and the receptor-binding "B" component for toxin delivery. Consistently, unlike other virulence factors such as effectors, AB toxins do not require additional systems to deliver them to the target host cells. Target host cells are located in the infection site and/or located distantly from infected host cells. The first part of this review discusses the structural and functional features of single-peptide and multiprotein AB toxins in the context of host-microbe interactions, using several well-characterized examples. The second part of this review discusses toxin neutralization strategies, as well as applications of AB toxins relevant to developing intervention strategies against diseases.
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8
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Ayub A, Usman M, Ihsan A, Ain Q, Awan AB, Wajid M, Ali A, Haque A, Iqbal M, Sarwar Y. Immunological characterization of chitosan adjuvanted outer membrane proteins of Salmonella enterica serovar Typhi as multi-epitope typhoid vaccine candidate. Mol Biol Rep 2022; 49:7377-7387. [PMID: 35713798 DOI: 10.1007/s11033-022-07531-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Outer membrane proteins (OMPs) of Gram-negative bacteria have been known as potential vaccine targets due to their antigenic properties and host specificity. Here, we focused on the exploration of the immunogenic potential and protective efficacy of total OMPs of Salmonella enterica serovar Typhi due to their multi epitope properties, adjuvanted with nanoporous chitosan particles (NPCPs). The study was designed to extrapolate an effective, low cost prophylactic approach for typhoid fever being getting uncontrolled in Pakistan due to emergence of extensively drug resistant (XDR) strains. METHODS & RESULTS The OMPs of two S. Typhi variants (with and without Vi capsule) alone and with nanoporous chitosan particles as adjuvant were comparatively analyzed for immunogenic potential in mice. Adaptive immunity was evaluated by ELISA and relative quantification of cytokine gene expression (IL4, IL6, IL9, IL17, IL10, TNF, INF and PPIA as house keeping gene) using RT-qPCR. Statistical analysis was done using Welch's test. The protection was recorded by challenging the immunized mice with 50% ×LD50 of S. Typhi. The Vi + ve-OMPs of S. Typhi showed the most promising results by ELISA and significantly high expression of IL-6, IL-10 and IL-17 and 92.5% protective efficacy with no detectable side effects. CONCLUSION We can conclude that the OMPs of Vi + ve S. Typhi are the most promising candidates for future typhoid vaccines because of cost effective preparation without expensive purification steps and multi-epitope properties. Chitosan adjuvant may have applications for oral protein based vaccines but found less effective in injectable preparations.
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Affiliation(s)
- Ambreen Ayub
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Muhammad Usman
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan
- Faculty of Veterinary and Animal Sciences, Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan
| | - Ayesha Ihsan
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Quratul Ain
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Asad Bashir Awan
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Muhammad Wajid
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Aamir Ali
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Abdul Haque
- Akhuwat Faisalabad Institute For Research In Science & Technology, Faisalabad, Pakistan
| | - Mazhar Iqbal
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Yasra Sarwar
- National Institute for Biotechnology & Genetic Engineering College (NIBGE-C), Faisalabad, Pakistan.
- Institute of Engineering & Applied Sciences (PIEAS), Islamabad, Pakistan.
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Kim C, Latif I, Neupane DP, Lee GY, Kwon RS, Batool A, Ahmed Q, Qamar MU, Song J. The molecular basis of extensively drug-resistant Salmonella Typhi isolates from pediatric septicemia patients. PLoS One 2021; 16:e0257744. [PMID: 34582469 PMCID: PMC8478237 DOI: 10.1371/journal.pone.0257744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/08/2021] [Indexed: 12/02/2022] Open
Abstract
Sepsis is a syndromic response to infections and is becoming an emerging threat to the public health sector, particularly in developing countries. Salmonella Typhi (S. Typhi), the cause of typhoid fever, is one primary cause of pediatric sepsis in typhoid endemic areas. Extensively drug-resistant (XDR) S. Typhi is more common among pediatric patients, which is responsible for over 90% of the reported XDR typhoid cases, but the majority of antibiotic resistance studies available have been carried out using S. Typhi isolates from adult patients. Here, we characterized antibiotic-resistance profiles of XDR S. Typhi isolates from a medium size cohort of pediatric typhoid patients (n = 45, 68.89% male and 31.11% female) and determined antibiotic-resistance-related gene signatures associated with common treatment options to typhoid fever patients of 18 XDR S. Typhi representing all 45 isolates. Their ages were 1–13 years old: toddlers aging 1–2 years old (n = 9, 20%), pre-schoolers aging 3–5 years old (n = 17, 37.78%), school-age children aging 6–12 years old (n = 17, 37.78%), and adolescents aging 13–18 years old (n = 2, 4.44%). Through analyzing blaTEM1, dhfR7, sul1, and catA1genes for multidrug-resistance, qnrS, gyrA, gyrB, parC, and parE for fluoroquinolone-resistance, blaCTX-M-15 for XDR, and macAB and acrAB efflux pump system-associated genes, we showed the phenotype of the XDR S. Typhi isolates matches with their genotypes featured by the acquisitions of the genes blaTEM1, dhfR7, sul1, catA1, qnrS, and blaCTX-M-15 and a point mutation on gyrA. This study informs the molecular basis of antibiotic-resistance among recent S. Typhi isolates from pediatric septicemia patients, therefore providing insights into the development of molecular detection methods and treatment strategies for XDR S. Typhi.
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Affiliation(s)
- Chanmi Kim
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Iqra Latif
- Faculty of Life Sciences, Department of Microbiology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Durga P. Neupane
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Gi Young Lee
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Ryan S. Kwon
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
| | - Alia Batool
- Department of Pathology, Fatima Memorial Hospital, Lahore, Pakistan
| | - Qasim Ahmed
- Department of Pathology, Fatima Memorial Hospital, Lahore, Pakistan
| | - Muhammad Usman Qamar
- Faculty of Life Sciences, Department of Microbiology, Government College University Faisalabad, Faisalabad, Pakistan
- * E-mail: (JS); (MUQ)
| | - Jeongmin Song
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States of America
- * E-mail: (JS); (MUQ)
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Ghorbani N, Assmar M, Amirmozafari N, Issazadeh K. Investigating the Efficiency of Recombinant FliC-Loaded Bacillus subtilis Spores in Mice Immunization against Salmonella enterica Serovar Typhi. IRANIAN JOURNAL OF PUBLIC HEALTH 2021; 50:1474-1482. [PMID: 34568187 PMCID: PMC8426781 DOI: 10.18502/ijph.v50i7.6638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 07/22/2020] [Indexed: 11/24/2022]
Abstract
Background: Bacterial spores are among the most efficient vaccine delivery vehicles. Because of their safety and efficacy, Bacillus subtilis spores are increasingly used in this regard. The negatively charged surfaces of the spores allow antigens to be adsorbed onto these structures. In this study, a candidate vaccine against Salmonella enterica serovar Typhi was adsorbed onto B. subtilis spores and the immunogenicity of the formulation was investigated in BALB/c mice. Methods: This work was performed during 2018–2019 in Islamic Azad University of Lahijan. FliC protein was recombinantly expressed in E. coli BL21 (DE3) cells and purified by affinity chromatography. On the other hand, B. subtilis strain PY79 (ATCC1609) was cultured in DSM medium and after the sporulation, FliC protein was adsorbed onto the spores in three different pH values (4, 7 and 10) and the adsorption was verified using dot-blot assay. FliC-adsorbed spores were then administered to BALB/c mice through the subcutaneous route. Mice immunization was evaluated by serum IgG assessment and challenge study. Results: FliC protein was successfully expressed and purified. Sporulation was controlled by phase-contrast microscopy. Serum IgG assay showed significant stimulation of the mice’s humoral immune system. Immunized mice were able to resist bacterial infection. Conclusion: The results showed the efficiency of spores as natural adjuvants for the stimulation of mice immune system. The formulation can be exploited for the delivery of recombinant vaccines against bacterial pathogens.
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Affiliation(s)
- Nafiseh Ghorbani
- Department of Microbiology, Faculty of Basic Sciences, Islamic Azad University of Lahijan, Lahijan, Iran
| | - Mehdi Assmar
- Department of Microbiology, Faculty of Basic Sciences, Islamic Azad University of Lahijan, Lahijan, Iran.,Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Nour Amirmozafari
- Department of Microbiology, Faculty of Basic Sciences, Islamic Azad University of Lahijan, Lahijan, Iran.,Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Khosrow Issazadeh
- Department of Microbiology, Faculty of Basic Sciences, Islamic Azad University of Lahijan, Lahijan, Iran
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Akbani SK, Bibi F. A Case Report of Extensively Drug Resistant Typhoid in Karachi, Pakistan: A Major Health Concern to Curb the Outbreak. EUROPEAN MEDICAL JOURNAL 2021. [DOI: 10.33590/emj/20-00217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The disease burden of extensively drug resistant typhoid in developing countries is a major emerging issue that cannot be ignored. Since its emergence from multidrug strains, the majority of typhoid cases in Karachi, Pakistan, have been extensively drug resistant, mostly infecting younger patients. In the study, the authors analysed one such case in an adolescent male and discussed how, by the implementation of national health policies, the spread of these infectious diseases could be prevented and the overall burden on the healthcare system decreased in areas with already limited resources.
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Affiliation(s)
| | - Fazeela Bibi
- Jinnah Medical and Dental College, Karachi, Pakistan
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Nguyen T, Richards AF, Neupane DP, Feathers JR, Yang YA, Sim JH, Byun H, Lee S, Ahn C, Van Slyke G, Fromme JC, Mantis NJ, Song J. The structural basis of Salmonella A 2B 5 toxin neutralization by antibodies targeting the glycan-receptor binding subunits. Cell Rep 2021; 36:109654. [PMID: 34496256 PMCID: PMC8459933 DOI: 10.1016/j.celrep.2021.109654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 06/02/2021] [Accepted: 08/11/2021] [Indexed: 11/15/2022] Open
Abstract
Many bacterial pathogens secrete A(2)B5 toxins comprising two functionally distinct yet complementary “A” and “B” subunits to benefit the pathogens during infection. The lectin-like pentameric B subunits recognize specific sets of host glycans to deliver the toxin into target host cells. Here, we offer the molecular mechanism by which neutralizing antibodies, which have the potential to bind to all glycan-receptor binding sites and thus completely inhibit toxin binding to host cells, are inhibited from exerting this action. Cryogenic electron microscopy (cryo-EM)-based analyses indicate that the skewed positioning of the toxin A subunit(s) toward one side of the toxin B pentamer inhibited neutralizing antibody binding to the laterally located epitopes, rendering some glycan-receptor binding sites that remained available for the toxin binding and endocytosis process, which is strikingly different from the counterpart antibodies recognizing the far side-located epitopes. These results highlight additional features of the toxin-antibody interactions and offer important insights into anti-toxin strategies. Nguyen et al. find that toxin-neutralizing antibodies targeting glycan-receptor binding B subunits can be split into two classes based on their epitope locations. They describe how these two classes exhibit significantly different neutralizing efficacies, a feature that appears to be shared among A(2)B5 toxins, and thus they provide insights into anti-toxin strategies.
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Affiliation(s)
- Tri Nguyen
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Angelene F Richards
- Department of Biomedical Sciences, University at Albany, Albany, NY 12222, USA
| | - Durga P Neupane
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - J Ryan Feathers
- Weill Institute for Cell and Molecular Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Yi-An Yang
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Ji Hyun Sim
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Haewon Byun
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Sohyoung Lee
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Changhwan Ahn
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA
| | - Greta Van Slyke
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA
| | - J Christopher Fromme
- Weill Institute for Cell and Molecular Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Nicholas J Mantis
- Department of Biomedical Sciences, University at Albany, Albany, NY 12222, USA; Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA
| | - Jeongmin Song
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853, USA.
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13
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Ahn C, Yang YA, Neupane DP, Nguyen T, Richards AF, Sim JH, Mantis NJ, Song J. Mechanisms of typhoid toxin neutralization by antibodies targeting glycan receptor binding and nuclease subunits. iScience 2021; 24:102454. [PMID: 34113815 PMCID: PMC8169802 DOI: 10.1016/j.isci.2021.102454] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 03/09/2021] [Accepted: 04/19/2021] [Indexed: 12/18/2022] Open
Abstract
Nearly all clinical isolates of Salmonella Typhi, the cause of typhoid fever, are antibiotic resistant. All S. Typhi isolates secrete an A2B5 exotoxin called typhoid toxin to benefit the pathogen during infection. Here, we demonstrate that antibiotic-resistant S. Typhi secretes typhoid toxin continuously during infection regardless of antibiotic treatment. We characterize typhoid toxin antibodies targeting glycan-receptor-binding PltB or nuclease CdtB, which neutralize typhoid toxin in vitro and in vivo, as demonstrated by using typhoid toxin secreted by antibiotic-resistant S. Typhi during human cell infection and lethal dose typhoid toxin challenge to mice. TyTx11 generated in this study neutralizes typhoid toxin effectively, comparable to TyTx4 that binds to all PltB subunits available per holotoxin. Cryoelectron microscopy explains that the binding of TyTx11 to CdtB makes this subunit inactive through CdtB catalytic-site conformational change. The identified toxin-neutralizing epitopes are conserved across all S. Typhi clinical isolates, offering critical insights into typhoid toxin-neutralizing strategies.
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Affiliation(s)
- Changhwan Ahn
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Yi-An Yang
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Durga P. Neupane
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Tri Nguyen
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | | | - Ji Hyun Sim
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Nicholas J. Mantis
- Department of Biomedical Sciences, University at Albany, Albany, NY 12222, USA
- Division of Infectious Diseases, Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA
| | - Jeongmin Song
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
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14
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Qazi SH, Yousafzai MT, Saddal NS, Dehraj IF, Thobani RS, Akhtar A, Syed JR, Kazi AM, Hotwani A, Rahman N, Mehmood J, Andrews JR, Luby SP, Garrett DO, Qamar FN. Burden of Ileal Perforations Among Surgical Patients Admitted in Tertiary Care Hospitals of Three Asian countries: Surveillance of Enteric Fever in Asia Project (SEAP), September 2016-September 2019. Clin Infect Dis 2021; 71:S232-S238. [PMID: 33258928 PMCID: PMC7705870 DOI: 10.1093/cid/ciaa1309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Background Typhoid fever is caused by Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) and can lead to systemic illness and complications. We aimed to characterize typhoid-related ileal perforation in the context of the population-based Surveillance of Enteric Fever in Asia Project (SEAP) in Bangladesh, Nepal and Pakistan. Methods Between September 2016 and September 2019, all cases of nontraumatic ileal perforation with a clinical diagnosis of typhoid were enrolled from 4 tertiary care hospitals in Karachi, 2 pediatric hospitals in Bangladesh, and 2 hospitals in Nepal. Sociodemographic data were collected from patients or their caregivers, and clinical and outcome data were retrieved from medical records. Tissue samples were collected for histopathology and blood cultures where available. Results Of the 249 enrolled cases, 2 from Bangladesh, 5 from Nepal and 242 from Pakistan. In Pakistan, most of the cases were in the 0–15 (117/242; 48%) and 16–30 (89/242; 37%) age groups. In all countries, males were most affected: Pakistan 74.9% (180/242), Nepal 80% (4/5), and Bangladesh 100% (2/2). Blood culture was done on 76 cases; 8 (11%) were positive for S. Typhi, and all were extensively drug resistant (XDR) S. Typhi. Tissue cultures was done on 86 patients; 3 (3%) were positive for S. Typhi, and all were XDR S. Typhi, out of 86 samples tested for histopathology 4 (5%) revealed ileal perforation with necrosis. Culture or histopathology confirmed total 15 (11%) enteric fever cases with ileal perforation are similar to the clinically diagnosed cases. There were 16/242 (7%) deaths from Pakistan. Cases of ileal perforation who survived were more likely to have sought care before visiting the sentinel hospital (P = .009), visited any hospital for treatment (P = .013) compared to those who survived. Conclusions Although surveillance differed substantially by country, one reason for the higher number of ileal perforation cases in Pakistan could be the circulation of XDR strain of S. Typhi in Karachi.
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Affiliation(s)
- Saqib H Qazi
- Section of Pediatric Surgery, Department of Surgery, Aga Khan University, Karachi, Pakistan
| | - Mohammad T Yousafzai
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | | | - Irum F Dehraj
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Rozina S Thobani
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Afshan Akhtar
- Aga Khan University Medical College, Karachi, Pakistan
| | - Jamal R Syed
- National Institute of Child Health, Karachi, Pakistan
| | - Abdul M Kazi
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Aneeta Hotwani
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Najeeb Rahman
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Junaid Mehmood
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
| | - Jason R Andrews
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - Stephen P Luby
- Division of Infectious Diseases and Geographic Medicine, Stanford University, Stanford, California, USA
| | - Denise O Garrett
- Applied Epidemiology, Sabin Vaccine Institute, Washington, DC, USA
| | - Farah N Qamar
- Department of Pediatrics and Child Health, Aga Khan University, Karachi, Pakistan
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15
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Enteric Fever Diagnosis: Current Challenges and Future Directions. Pathogens 2021; 10:pathogens10040410. [PMID: 33915749 PMCID: PMC8065732 DOI: 10.3390/pathogens10040410] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/23/2021] [Accepted: 03/27/2021] [Indexed: 12/21/2022] Open
Abstract
Enteric fever is a life-threatening systemic febrile disease caused by Salmonella enterica serovars Typhi and Paratyphi (S. Typhi and S. Paratyphi). Unfortunately, the burden of the disease remains high primarily due to the global spread of various drug-resistant Salmonella strains despite continuous advancement in the field. An accurate diagnosis is critical for effective control of the disease. However, enteric fever diagnosis based on clinical presentations is challenging due to overlapping symptoms with other febrile illnesses that are also prevalent in endemic areas. Current laboratory tests display suboptimal sensitivity and specificity, and no diagnostic methods are available for identifying asymptomatic carriers. Several research programs have employed systemic approaches to identify more specific biomarkers for early detection and asymptomatic carrier detection. This review discusses the pros and cons of currently available diagnostic tests for enteric fever, the advancement of research toward improved diagnostic tests, and the challenges of discovering new ideal biomarkers and tests.
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16
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Kwon J, Kim SG, Kim HJ, Giri SS, Kim SW, Lee SB, Park SC. Bacteriophage as an alternative to prevent reptile-associated Salmonella transmission. Zoonoses Public Health 2021; 68:131-143. [PMID: 33455089 DOI: 10.1111/zph.12804] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/25/2020] [Accepted: 12/26/2020] [Indexed: 01/21/2023]
Abstract
Salmonellosis is a major global public health issue; its most common infection, gastroenteritis, accounts for approximately 90 million illnesses and 150,000 mortalities per year. Eradicating salmonellosis requires surveillance, prevention and treatment, entailing large expenditures. However, it is difficult to control Salmonella transmission because it occurs via multiple routes; exotic reptiles are a reservoir of Salmonella and comprise one such route. As the popularity of exotic pets and animal exhibition has increased, human encounters with reptiles have also increased. As a result, reptile-associated salmonellosis (RAS) has been recognized as an emerging disease. The development of antimicrobial resistance in RAS-causing Salmonella sp. requires alternatives to antibiotics. In this study, bacteriophages have been established as an alternative to antibiotics because only target bacteria are lysed; thus, they are promising biocontrol agents. Here, bacteriophage pSal-SNUABM-02, which infects and lyses reptile Salmonella isolates, was isolated and characterized. The morphology, host range, growth traits and stability of the phage were investigated. The phage was assigned to Myoviridae and was stable in the following conditions: pH 5-9, 4-37°C, and ultravioletA/ultravioletB (UVA/UVB) exposure. Salmonella clearance efficacy was tested using planktonic cell lysis activity and biofilm degradation on polystyrene 96-well plates and reptile skin fragments. The phage exhibited vigorous lysis activity against planktonic cells. In in vitro biofilm degradation tests on reptile skin and polystyrene plates, both low- and high-concentration phage treatments lowered bacterial cell viability by approximately 2.5-3 log colony-forming units and also decreased biomass. Thus, bacteriophages are a promising alternative to antibiotics for the prevention and eradication of RAS.
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Affiliation(s)
- Jun Kwon
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sang Geun Kim
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Hyoun Joong Kim
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sib Sankar Giri
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sang Wha Kim
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sung Bin Lee
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Se Chang Park
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
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17
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Masuet-Aumatell C, Atouguia J. Typhoid fever infection - Antibiotic resistance and vaccination strategies: A narrative review. Travel Med Infect Dis 2020; 40:101946. [PMID: 33301931 DOI: 10.1016/j.tmaid.2020.101946] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 02/07/2023]
Abstract
Typhoid fever is a bacterial infection caused by the Gram-negative bacterium Salmonella enterica subspecies enterica serovar Typhi (S. Typhi), prevalent in many low- and middle-income countries. In high-income territories, typhoid fever is predominantly travel-related, consequent to travel in typhoid-endemic regions; however, data show that the level of typhoid vaccination in travellers is low. Successful management of typhoid fever using antibiotics is becoming increasingly difficult due to drug resistance; emerging resistance has spread geographically due to factors such as increasing travel connectivity, affecting those in endemic regions and travellers alike. This review provides an overview of: the epidemiology and diagnosis of typhoid fever; the emergence of drug-resistant typhoid strains in the endemic setting; drug resistance observed in travellers; vaccines currently available to prevent typhoid fever; vaccine recommendations for people living in typhoid-endemic regions; strategies for the introduction of typhoid vaccines and stakeholders in vaccination programmes; and travel recommendations for a selection of destinations with a medium or high incidence of typhoid fever.
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Affiliation(s)
- Cristina Masuet-Aumatell
- Preventive Medicine Department, Bellvitge Biomedical Research Institute (IDIBELL), University Hospital of Bellvitge, Faculty of Medicine, University of Barcelona, Feixa Llarga s/n, L'Hospitalet de Llobregat, 08907, Barcelona, Catalonia, Spain.
| | - Jorge Atouguia
- Instituto Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junquiera, 100, Lisbon, Portugal.
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18
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Vishvakarma VK, Chandra R, Singh P. An Experimental and Theoretical Approach to Understand Fever, DENF & its Cure. Infect Disord Drug Targets 2020; 21:495-513. [PMID: 32888275 DOI: 10.2174/1871526520999200905122052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/21/2020] [Accepted: 07/17/2020] [Indexed: 11/22/2022]
Abstract
Fever is a response of a human body, due to an increase in the temperature, against certain stimuli. It may be associated with several reasons and one of the major causes of fever is a mosquito bite. Fever due to dengue virus (DENV) infection is being paid most attention out of several other fever types because of a large number of deaths reported worldwide. Dengue virus is transmitted by biting of the mosquitoes, Aedes aegypti and Aedes albopictus. DENV1, DENV2, DENV3 and DENV4 are the four serotypes of dengue virus and these serotypes have 65% similarities in their genomic structure. The genome of DENV is composed of single-stranded RNA and it encodes for the polyprotein. Structural and non-structural proteins (nsP) are the two major parts of polyprotein. Researchers have paid high attention to the non-structural protease (nsP) of DENV like nsP1, nsP2A, nsP2B, nsP3, nsP4A, nsP4B and nsP5. The NS2B-NS3 protease of DENV is the prime target of the researchers as it is responsible for the catalytic activity. In the present time, Dengvaxia (vaccine) is being recommended to patients suffering severely from DENV infection in few countries only. Till date, neither a vaccine nor an effective medicine is available to combat all four serotypes. This review describes the fever, its causes, and studies to cure the infection due to DENV using theoretical and experimental approaches.
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Affiliation(s)
- Vijay Kumar Vishvakarma
- Department of Chemistry, Atma Ram Sanatan Dharma College, University of Delhi, New Delhi, India
| | - Ramesh Chandra
- Drug Discovery & Development Laboratory, Department of Chemistry, University of Delhi, Delhi, India
| | - Prashant Singh
- Department of Chemistry, Atma Ram Sanatan Dharma College, University of Delhi, New Delhi, India
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19
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Lee S, Yang YA, Milano SK, Nguyen T, Ahn C, Sim JH, Thompson AJ, Hillpot EC, Yoo G, Paulson JC, Song J. Salmonella Typhoid Toxin PltB Subunit and Its Non-typhoidal Salmonella Ortholog Confer Differential Host Adaptation and Virulence. Cell Host Microbe 2020; 27:937-949.e6. [PMID: 32396840 DOI: 10.1016/j.chom.2020.04.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 02/18/2020] [Accepted: 04/03/2020] [Indexed: 01/19/2023]
Abstract
Typhoidal and non-typhoidal Salmonelleae (NTS) cause typhoid fever and gastroenteritis, respectively, in humans. Salmonella typhoid toxin contributes to typhoid disease progression and chronic infection, but little is known about the role of its NTS ortholog. We found that typhoid toxin and its NTS ortholog induce different clinical presentations. The PltB subunit of each toxin exhibits different glycan-binding preferences that correlate with glycan expression profiles of host cells targeted by each bacterium at the primary infection or intoxication sites. Through co-crystal structures of PltB subunits bound to specific glycan receptor moieties, we show that they induce markedly different glycan-binding preferences and virulence outcomes. Furthermore, immunization with the NTS S. Javiana or its toxin offers cross-reactive protection against lethal-dose typhoid toxin challenge. Cumulatively, these results offer insights into the evolution of host adaptations in Salmonella AB toxins, their cell and tissue tropisms, and the design for improved typhoid vaccines and therapeutics.
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Affiliation(s)
- Sohyoung Lee
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Yi-An Yang
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Shawn K Milano
- Department of Molecular Medicine, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Tri Nguyen
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Changhwan Ahn
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Ji Hyun Sim
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Andrew J Thompson
- Department of Molecular Medicine, the Scripps Research Institute, La Jolla, CA 92121, USA
| | - Eric C Hillpot
- Department of Molecular Medicine, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Gyeongshik Yoo
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - James C Paulson
- Department of Molecular Medicine, the Scripps Research Institute, La Jolla, CA 92121, USA
| | - Jeongmin Song
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA.
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20
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Ibler AEM, ElGhazaly M, Naylor KL, Bulgakova NA, F El-Khamisy S, Humphreys D. Typhoid toxin exhausts the RPA response to DNA replication stress driving senescence and Salmonella infection. Nat Commun 2019; 10:4040. [PMID: 31492859 PMCID: PMC6731267 DOI: 10.1038/s41467-019-12064-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 08/15/2019] [Indexed: 01/10/2023] Open
Abstract
Salmonella Typhi activates the host DNA damage response through the typhoid toxin, facilitating typhoid symptoms and chronic infections. Here we reveal a non-canonical DNA damage response, which we call RING (response induced by a genotoxin), characterized by accumulation of phosphorylated histone H2AX (γH2AX) at the nuclear periphery. RING is the result of persistent DNA damage mediated by toxin nuclease activity and is characterized by hyperphosphorylation of RPA, a sensor of single-stranded DNA (ssDNA) and DNA replication stress. The toxin overloads the RPA pathway with ssDNA substrate, causing RPA exhaustion and senescence. Senescence is also induced by canonical γΗ2ΑΧ foci revealing distinct mechanisms. Senescence is transmitted to non-intoxicated bystander cells by an unidentified senescence-associated secreted factor that enhances Salmonella infections. Thus, our work uncovers a mechanism by which genotoxic Salmonella exhausts the RPA response by inducing ssDNA formation, driving host cell senescence and facilitating infection.
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Affiliation(s)
- Angela E M Ibler
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
- Department of Pathology, Tennis Court Road, University of Cambridge, Cambridge, CB2 1QP, UK
| | - Mohamed ElGhazaly
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Kathryn L Naylor
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Natalia A Bulgakova
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK
| | - Sherif F El-Khamisy
- The Healthy Life Span Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
- Center of Genomics, Zewail City of Science and Technology, Giza, Egypt
| | - Daniel Humphreys
- Department of Biomedical Science, University of Sheffield, Sheffield, S10 2TN, UK.
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