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Chakraborty S, Dutta P, Pal A, Chakraborty S, Banik G, Halder P, Gope A, Miyoshi SI, Das S. Intranasal immunization of mice with chimera of Salmonella Typhi protein elicits protective intestinal immunity. NPJ Vaccines 2024; 9:24. [PMID: 38321067 PMCID: PMC10847434 DOI: 10.1038/s41541-024-00812-4] [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: 06/14/2023] [Accepted: 01/26/2024] [Indexed: 02/08/2024] Open
Abstract
Development of safe, highly effective and affordable enteric fever vaccines is a global health priority. Live, oral typhoid vaccines induce strong mucosal immunity and long-term protection, but safety remains a concern. In contrast, efficacy wears off rapidly for injectable, polysaccharide-based vaccines, which elicit poor mucosal response. We previously reported Salmonella Typhi outer membrane protein, T2544 as a potential candidate for bivalent (S. Typhi and S. Paratyphi A) vaccine development. Here, we show that intranasal immunization with a subunit vaccine (chimera of T2544 and cholera toxin B subunit) induced strong systemic and intestinal mucosal immunity and protection from S. Typhi challenge in a mouse model. CTB-T2544 augmented gut-homing receptor expression on lymphocytes that produced Th1 and Th17 cytokines, secretory IgA in stool that inhibited bacterial motility and epithelial attachment, antibody recall response and affinity maturation with increased number of follicular helper T cells and CD4+ central and effector memory cells.
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Affiliation(s)
- Suparna Chakraborty
- Division of Clinical Medicine, ICMR- National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Beliaghata, Kolkata, 700 010, India
| | - Pujarini Dutta
- Division of Clinical Medicine, ICMR- National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Beliaghata, Kolkata, 700 010, India
- Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tuscon, AZ, USA
| | - Ananda Pal
- Division of Clinical Medicine, ICMR- National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Beliaghata, Kolkata, 700 010, India
| | - Swarnali Chakraborty
- Division of Clinical Medicine, ICMR- National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Beliaghata, Kolkata, 700 010, India
| | - George Banik
- BD Biosciences, INDIA, Smart works Business Center, Victoria Park, 37/2 GN Block, Sector 5, Saltlake City, Kolkata, 700091, India
| | - Prolay Halder
- Division of Bacteriology, ICMR- National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Beliaghata, Kolkata, 700 010, India
| | - Animesh Gope
- Division of Clinical Medicine, ICMR- National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Beliaghata, Kolkata, 700 010, India
| | - Shin-Ichi Miyoshi
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
- Collaborative Research Center of Okayama University for Infectious Diseases at Indian Council of Medical Research-National Institute of Cholera and Enteric Diseases, Kolkata, 700010, India
| | - Santasabuj Das
- Division of Clinical Medicine, ICMR- National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Beliaghata, Kolkata, 700 010, India.
- ICMR-National Institute of Occupational Health, Meghaninagar, Ahmedabad, 3800016, Gujarat, India.
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Haldar R, Dhar A, Ganguli D, Chakraborty S, Pal A, Banik G, Miyoshi SI, Das S. A candidate glycoconjugate vaccine induces protective antibodies in the serum and intestinal secretions, antibody recall response and memory T cells and protects against both typhoidal and non-typhoidal Salmonella serovars. Front Immunol 2024; 14:1304170. [PMID: 38264668 PMCID: PMC10804610 DOI: 10.3389/fimmu.2023.1304170] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 12/18/2023] [Indexed: 01/25/2024] Open
Abstract
Human Salmonella infections pose significant public health challenges globally, primarily due to low diagnostic yield of systemic infections, emerging and expanding antibiotic resistance of both the typhoidal and non-typhoidal Salmonella strains and the development of asymptomatic carrier state that functions as a reservoir of infection in the community. The limited long-term efficacy of the currently licensed typhoid vaccines, especially in smaller children and non-availability of vaccines against other Salmonella serovars necessitate active research towards developing a multivalent vaccine with wider coverage of protection against pathogenic Salmonella serovars. We had earlier reported immunogenicity and protective efficacy of a subunit vaccine containing a recombinant outer membrane protein (T2544) of Salmonella Typhi in a mouse model. This was achieved through the robust induction of serum IgG, mucosal secretory IgA and Salmonella-specific cytotoxic T cells as well as memory B and T cell response. Here, we report the development of a glycoconjugate vaccine, containing high molecular weight complexes of Salmonella Typhimurium O-specific polysaccharide (OSP) and recombinant T2544 that conferred simultaneous protection against S. Typhi, S. Paratyphi, S. Typhimurium and cross-protection against S. enteritidis in mice. Our findings corroborate with the published studies that suggested the potential of Salmonella OSP as a vaccine antigen. The role of serum antibodies in vaccine-mediated protection is suggested by rapid seroconversion with high titers of serum IgG and IgA, persistently elevated titers after primary immunization along with a strong antibody recall response with higher avidity serum IgG against both OSP and T2544 and significantly raised SBA titers of both primary and secondary antibodies against different Salmonella serovars. Elevated intestinal secretory IgA and bacterial motility inhibition by the secretory antibodies supported their role as well in vaccine-induced protection. Finally, robust induction of T effector memory response indicates long term efficacy of the candidate vaccine. The above findings coupled with protection of vaccinated animals against multiple clinical isolates confirm the suitability of OSP-rT2544 as a broad-spectrum candidate subunit vaccine against human infection due to typhoidal and non-typhoidal Salmonella serovars.
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Affiliation(s)
- Risha Haldar
- Division of Clinical Medicine, Indian Council of Medical Research (ICMR)-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Amlanjyoti Dhar
- Division of Molecular Biology and Genomics, International Institute of Innovation and Technology (I3T), Kolkata, India
| | - Debayan Ganguli
- Department of Infectious Diseases, Washington University School of Medicine at St. Louis, St. Louis, MO, United States
| | - Suparna Chakraborty
- Division of Clinical Medicine, Indian Council of Medical Research (ICMR)-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Ananda Pal
- Division of Clinical Medicine, Indian Council of Medical Research (ICMR)-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | | | - Shin-ichi Miyoshi
- Division of Medicine, Dentistry and Pharmaceutical Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Santasabuj Das
- Division of Clinical Medicine, Indian Council of Medical Research (ICMR)-National Institute of Cholera and Enteric Diseases, Kolkata, India
- Division of Biological Science, Indian Council of Medical Research (ICMR)-National Institute of Occupational Health, Ahmedabad, India
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Choudhury M, Borah P, Sarma HK, Deka D, Dutta R, Hazarika G, Deka NK. Development of recombinant subunit vaccine targeting InvH protein of Salmonella Typhimurium and evaluation of its immunoprotective efficacy against salmonellosis. Braz J Microbiol 2023; 54:3257-3264. [PMID: 37792270 PMCID: PMC10689308 DOI: 10.1007/s42770-023-01136-6] [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: 09/01/2022] [Accepted: 09/25/2023] [Indexed: 10/05/2023] Open
Abstract
Salmonella Typhimurium is the most prevalent non-host specific Salmonella serovars and a major concern for both human and animal health systems worldwide contributing to significant economic loss. Type 3 secretion system (T3SS) of Salmonella plays an important role in bacterial adherence and entry into the host epithelial cells. The product of invH gene of Salmonella is an important component of the needle complex of the type 3 secretion system. Hence, the present study was undertaken to clone and express the 15 kDa InvH surface protein of Salmonella Typhimurium in an E. coli host and to evaluate its immune potency in mice. The purified recombinant InvH (r-InvH) protein provoked a significant (p < 0.01) rise in IgG in the inoculated mice. The immunized mice were completely (100%) protected against the challenge dose of 107.5 LD50, while protection against challenge with the same dose of heterologous serovars was 90%. The bacterin-vaccinated group showed homologous protection of 60% against all three serovars. Findings in this study suggest the potential of the r-InvH protein of S. Typhimurium as an effective vaccine candidate against Salmonella infections.
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Affiliation(s)
| | - Probodh Borah
- Department of Animal Biotechnology, College of Veterinary Science, Assam Agriculture University, Khanapara, Guwahati, 781022, India.
| | - Hridip Kumar Sarma
- Department of Biotechnology, Gauhati University, Guwahati, 781014, Assam, India
| | - Dipak Deka
- Department of Animal Biotechnology, College of Veterinary Science, Assam Agriculture University, Khanapara, Guwahati, 781022, India
| | - Rupam Dutta
- Department of Animal Biotechnology, College of Veterinary Science, Assam Agriculture University, Khanapara, Guwahati, 781022, India
| | - Girin Hazarika
- Department of Animal Biotechnology, College of Veterinary Science, Assam Agriculture University, Khanapara, Guwahati, 781022, India
| | - Naba Kumar Deka
- Department of Biotechnology, Gauhati University, Guwahati, 781014, Assam, India
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Li W, Ren Q, Ni T, Zhao Y, Sang Z, Luo R, Li Z, Li S. Strategies adopted by Salmonella to survive in host: a review. Arch Microbiol 2023; 205:362. [PMID: 37904066 DOI: 10.1007/s00203-023-03702-w] [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: 09/01/2023] [Revised: 09/30/2023] [Accepted: 10/05/2023] [Indexed: 11/01/2023]
Abstract
Salmonella, a Gram-negative bacterium that infects humans and animals, causes diseases ranging from gastroenteritis to severe systemic infections. Here, we discuss various strategies used by Salmonella against host cell defenses. Epithelial cell invasion largely depends on a Salmonella pathogenicity island (SPI)-1-encoded type 3 secretion system, a molecular syringe for injecting effector proteins directly into host cells. The internalization of Salmonella into macrophages is primarily driven by phagocytosis. After entering the host cell cytoplasm, Salmonella releases many effectors to achieve intracellular survival and replication using several secretion systems, primarily an SPI-2-encoded type 3 secretion system. Salmonella-containing vacuoles protect Salmonella from contacting bactericidal substances in epithelial cells and macrophages. Salmonella modulates the immunity, metabolism, cell cycle, and viability of host cells to expand its survival in the host, and the intracellular environment of Salmonella-infected cells promotes its virulence. This review provides insights into how Salmonella subverts host cell defenses for survival.
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Affiliation(s)
- Wanwu Li
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, China
| | - Qili Ren
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, China
| | - Ting Ni
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, China
| | - Yifei Zhao
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, China
| | - Zichun Sang
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, China
| | - Renli Luo
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, China
| | - Zhongjie Li
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, China.
| | - Sanqiang Li
- College of Basic Medicine and Forensic Medicine, Henan University of Science and Technology, Luoyang, China.
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Gadar K, McCarthy RR. Using next generation antimicrobials to target the mechanisms of infection. NPJ ANTIMICROBIALS AND RESISTANCE 2023; 1:11. [PMID: 38686217 PMCID: PMC11057201 DOI: 10.1038/s44259-023-00011-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 07/28/2023] [Indexed: 05/02/2024]
Abstract
The remarkable impact of antibiotics on human health is being eroded at an alarming rate by the emergence of multidrug resistant pathogens. There is a recognised consensus that new strategies to tackle infection are urgently needed to limit the devasting impact of antibiotic resistance on our global healthcare infrastructure. Next generation antimicrobials (NGAs) are compounds that target bacterial virulence factors to disrupt pathogenic potential without impacting bacterial viability. By disabling the key virulence factors required to establish and maintain infection, NGAs make pathogens more vulnerable to clearance by the immune system and can potentially render them more susceptible to traditional antibiotics. In this review, we discuss the developing field of NGAs and how advancements in this area could offer a viable standalone alternative to traditional antibiotics or an effective means to prolong antibiotic efficacy when used in combination.
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Affiliation(s)
- Kavita Gadar
- Division of Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UB8 3PH United Kingdom
| | - Ronan R. McCarthy
- Division of Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UB8 3PH United Kingdom
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Ling C, Liang S, Li Y, Cao Q, Ye H, Zhang C, Dong Z, Feng D, Wang W, Zuo J. A Potential Adhesin/Invasin STM0306 Participates in Host Cell Inflammation Induced by Salmonella enterica Serovar Typhimurium. Int J Mol Sci 2023; 24:ijms24098170. [PMID: 37175877 PMCID: PMC10179656 DOI: 10.3390/ijms24098170] [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: 02/17/2023] [Revised: 04/04/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Salmonella enterica serovar typhimurium (S. Typhimurium) is a common Gram-negative foodborne pathogenic bacterium that causes gastrointestinal disease in humans and animals. It is well known that adhesins and invasins play crucial roles in the infection mechanism of S. Typhimurium. S. Typhimurium STM0306 has been denoted as a putative protein and its functions have rarely been reported. In this study, we constructed the STM0306 gene mutant strain of S. Typhimurium and purified the recombinant STM0306 from Escherichia coli. Deletion of the STM0306 gene resulted in reduced adhesion and invasion of S. Typhimurium to IPEC-J2, Caco-2, and RAW264.7 cells. In addition, STM0306 could bind to intestinal epithelial cells and induced F-actin modulation in IPEC-J2 cells. Furthermore, we found that STM0306 activated the nuclear factor kappa B (NF-κB) signaling pathway and increased the mRNA expression of pro-inflammatory cytokines such as IL-1β, TNF-α, as well as chemokine CXCL2, thus resulting in cellular inflammation in host cells. In vivo, the deletion of the STM0306 gene led to reduced pathogenicity of S. Typhimurium, as evidenced by lower fecal bacterial counts and reduced body weight loss in S. Typhimurium infected mice. In conclusion, the STM0306 of S. Typhimurium is an important adhesin/invasin involved in the pathogenic process and cellular inflammation of the host.
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Affiliation(s)
- Chong Ling
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Shujie Liang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Yan Li
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Qingyun Cao
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Hui Ye
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Changming Zhang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Zemin Dong
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Dingyuan Feng
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Weiwei Wang
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
| | - Jianjun Zuo
- Guangdong Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou 510642, China
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Jiang Z, Kang X, Song Y, Zhou X, Yue M. Identification and Evaluation of Novel Antigen Candidates against Salmonella Pullorum Infection Using Reverse Vaccinology. Vaccines (Basel) 2023; 11:vaccines11040865. [PMID: 37112777 PMCID: PMC10143441 DOI: 10.3390/vaccines11040865] [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: 03/24/2023] [Revised: 04/06/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Pullorum disease, caused by the Salmonella enterica serovar Gallinarum biovar Pullorum, is a highly contagious disease in the poultry industry, leading to significant economic losses in many developing countries. Due to the emergence of multidrug-resistant (MDR) strains, immediate attention is required to prevent their endemics and global spreading. To mitigate the prevalence of MDR Salmonella Pullorum infections in poultry farms, it is urgent to develop effective vaccines. Reverse vaccinology (RV) is a promising approach using expressed genomic sequences to find new vaccine targets. The present study used the RV approach to identify new antigen candidates against Pullorum disease. Initial epidemiological investigation and virulent assays were conducted to select strain R51 for presentative and general importance. An additional complete genome sequence (4.7 Mb) for R51 was resolved using the Pacbio RS II platform. The proteome of Salmonella Pullorum was analyzed to predict outer membrane and extracellular proteins, and was further selected for evaluating transmembrane domains, protein prevalence, antigenicity, and solubility. Twenty-two high-scored proteins were identified among 4713 proteins, with 18 recombinant proteins successfully expressed and purified. The chick embryo model was used to assess protection efficacy, in which vaccine candidates were injected into 18-day-old chick embryos for in vivo immunogenicity and protective effects. The results showed that the PstS, SinH, LpfB, and SthB vaccine candidates were able to elicit a significant immune response. Particularly, PstS confers a significant protective effect, with a 75% survival rate compared to 31.25% for the PBS control group, confirming that identified antigens can be promising targets against Salmonella Pullorum infection. Thus, we offer RV to discover novel effective antigens in an important veterinary infectious agent with high priority.
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Affiliation(s)
- Zhijie Jiang
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiamei Kang
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yan Song
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiao Zhou
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Min Yue
- Institute of Preventive Veterinary Sciences, Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
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Safi AUR, Bendixen E, Rahman H, Khattak B, Wu W, Ullah W, Khan N, Ali F, Yasin N, Qasim M. Molecular identification and differential proteomics of drug resistant Salmonella Typhi. Diagn Microbiol Infect Dis 2023; 105:115883. [PMID: 36731197 DOI: 10.1016/j.diagmicrobio.2022.115883] [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: 04/09/2022] [Revised: 12/04/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022]
Abstract
This study aimed to elucidate differentially expressed proteins in drug resistant Salmonella Typhi. Among 100 samples, S. typhi were identified in 43 samples. In drug susceptibility profile, 95.3% (41/43), 80% (35/43) and 70% (30/43) resistances were observed against Nalidixic acid, Ampicillin, and Chloramphenicol respectively. No resistance was observed against Imipenum and Azithromycin while only 11% (5/43) isolates were found resistant to Ceftriaxone. Mass spectrometric differential analysis resulted in 23 up-regulated proteins in drug resistant isolates. Proteins found up-regulated are involved in virulence (vipB, galU, tufA, and lpp1), translation (rpsF, rpsG, rplJ, and rplR), antibiotic resistance (zwf, phoP, and ompX), cell metabolism (metK, ftsZ, pepD, and secB), stress response (ridA, rbfA, and dps), housekeeping (gapA and eno) and hypothetical proteins including ydfZ, t1802, and yajQ. These proteins are of diverse nature and functions but highly interconnected. Further characterization may be helpful for elucidation of new biomarker proteins and therapeutic drug targets.
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Affiliation(s)
- Aziz Ur Rehman Safi
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Emoke Bendixen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C Denmark
| | - Hazir Rahman
- Department of Microbiology, Abdul Wali Khan University Mardan, Mardan Pakistan
| | - Baharullah Khattak
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Wei Wu
- College of Animal Sciences and Technology, Southwest University, Chongqing China
| | - Waheed Ullah
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Nasar Khan
- Department of Microbiology, Kohsar University Murree, Kashmir Point, Punjab, Pakistan
| | - Farhad Ali
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Nusrat Yasin
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan
| | - Muhammad Qasim
- Department of Microbiology, Kohat University of Science and Technology, Kohat Pakistan.
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Vij S, Thakur R, Rishi P. Reverse engineering approach: a step towards a new era of vaccinology with special reference to Salmonella. Expert Rev Vaccines 2022; 21:1763-1785. [PMID: 36408592 DOI: 10.1080/14760584.2022.2148661] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Salmonella is responsible for causing enteric fever, septicemia, and gastroenteritis in humans. Due to high disease burden and emergence of multi- and extensively drug-resistant Salmonella strains, it is becoming difficult to treat the infection with existing battery of antibiotics as we are not able to discover newer antibiotics at the same pace at which the pathogens are acquiring resistance. Though vaccines against Salmonella are available commercially, they have limited efficacy. Advancements in genome sequencing technologies and immunoinformatics approaches have solved the problem significantly by giving rise to a new era of vaccine designing, i.e. 'Reverse engineering.' Reverse engineering/vaccinology has expedited the vaccine identification process. Using this approach, multiple potential proteins/epitopes can be identified and constructed as a single entity to tackle enteric fever. AREAS COVERED This review provides details of reverse engineering approach and discusses various protein and epitope-based vaccine candidates identified using this approach against typhoidal Salmonella. EXPERT OPINION Reverse engineering approach holds great promise for developing strategies to tackle the pathogen(s) by overcoming the limitations posed by existing vaccines. Progressive advancements in the arena of reverse vaccinology, structural biology, and systems biology combined with an improved understanding of host-pathogen interactions are essential components to design new-generation vaccines.
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Affiliation(s)
- Shania Vij
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Reena Thakur
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Praveen Rishi
- Department of Microbiology, Panjab University, Chandigarh, India
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Ur Rehman Safi A, Mansour Salih M, Rahman H, Khattak B, El Askary A, Hussain Khalifa E, Qasim M. Immunoaffinity-based mass spectrometric characterization of immunoreactive proteins of Salmonella Typhi. Saudi J Biol Sci 2022; 30:103502. [DOI: 10.1016/j.sjbs.2022.103502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/14/2022] [Accepted: 11/10/2022] [Indexed: 11/18/2022] Open
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Singh Y, Saxena A, Singh SP, Verma MK, Kumar A, Kumar A, Mrigesh M, Saxena MK. Calcium phosphate adjuvanted nanoparticles of outer membrane proteins of Salmonella Typhi as a candidate for vaccine development against Typhoid fever. J Med Microbiol 2022; 71. [PMID: 35476604 DOI: 10.1099/jmm.0.001529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Introduction. The conventional adjuvants used in vaccines have limitations like induction of an imbalanced Th1 and Th2 immune response. To overcome this limitation, novel adjuvants and newer forms of existing adjuvants like calcium phosphate nanoparticles are being tested.Hypothesis/Gap Statement. Calcium phosphate adjuvanted outer membrane proteins vaccine may work as an efficient, safe and cost effective vaccine against Salmonella Typhi.Aim. Our goals were to evaluate the potential of calcium phosphate nanoparticles as an adjuvant using outer membrane proteins (Omps) of Salmonella Typhi as antigens for immune response, with montanide (commercially available adjuvant) as control, and its toxicity in rats.Methodology. Calcium phosphate adjuvanted outer membrane proteins nanoparticles were synthesized and characterized. The efficacy of vaccine formulation in mice and toxicity assay were carried out in rats.Results. The calcium phosphate nanoparticles varying in size between 20-50 nm had entrapment efficiency of 41.5% and loading capacity of 54%. The calcium phosphate nanoparticle-Omps vaccine formulation (nanoparticle-Omps) induced a strong humoral immune response, which was significantly higher than the control group for the entire period of study. In the montanide-Omps group the initial very high immune response declined steeply and then remained steady. The immune response induced by nanoparticle-Omps did not change appreciably. The cell mediated immune response as measured by lymphocyte proliferation assay and delayed type hypersensitivity test showed a higher response (P<0.01) for the nanoparticles-Omps group as compared to montanide-Omps group. The bacterial clearance assay also showed higher clearance in the nanoparticles-Omps group as compared to montanide-Omps group (approx 1.4%). The toxicity analysis in rats showed no difference in the values of toxicity biomarkers and blood chemistry parameters, revealing vaccine formulation was non-toxic in rats.Conclusion. Calcium phosphate nanoparticles as adjuvant in vaccines is safe, have good encapsulation and loading capacity and induce a strong cell mediated, humoral and protective immune response.
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Affiliation(s)
- Yashpal Singh
- Department of Molecular Biology & Genetic Engineering, College of Basic Sciences & Humanities, Pantnagar, Uttarakhand, India
| | - Anjani Saxena
- Department of Veterinary Pharmacology & Toxicology, College of Veterinary & Animal Sciences, Pantnagar, Uttarakhand, India
| | - S P Singh
- Department of Veterinary Pharmacology & Toxicology, College of Veterinary & Animal Sciences, Pantnagar, Uttarakhand, India
| | - Manish Kumar Verma
- Department of Veterinary Pharmacology & Toxicology, College of Veterinary & Animal Sciences, Pantnagar, Uttarakhand, India
| | - Arun Kumar
- Department of Veterinary Surgery and Radiology, College of Veterinary & Animal Sciences, Pantnagar, Uttarakhand, India
| | - Avadhesh Kumar
- Department of Veterinary & Animal Husbandry Extension Education, College of Veterinary & Animal Sciences, Pantnagar, Uttarakhand, India
| | - Meena Mrigesh
- Department of Veterinary Anatomy, College of Veterinary & Animal Sciences, Pantnagar, Uttarakhand, India
| | - Mumtesh Kumar Saxena
- Department of Animal Genetics & Breeding, College of Veterinary & Animal Sciences G.B. Pant University of Agriculture & Technology, Pantnagar, Uttarakhand, India
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Roche SM, Holbert S, Le Vern Y, Rossignol C, Rossignol A, Velge P, Virlogeux-Payant I. A large panel of chicken cells are invaded in vivo by Salmonella Typhimurium even when depleted of all known invasion factors. Open Biol 2021; 11:210117. [PMID: 34784793 PMCID: PMC8596019 DOI: 10.1098/rsob.210117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Poultry are the main source of human infection by Salmonella. As infected poultry are asymptomatic, identifying infected poultry farms is difficult, thus controlling animal infections is of primary importance. As cell tropism is known to govern disease, our aim was therefore to identify infected host-cell types in the organs of chicks known to be involved in Salmonella infection and investigate the role of the three known invasion factors in this process (T3SS-1, Rck and PagN). Chicks were inoculated with wild-type or isogenic fluorescent Salmonella Typhimurium mutants via the intracoelomic route. Our results show that liver, spleen, gall bladder and aortic vessels could be foci of infection, and that phagocytic and non-phagocytic cells, including immune, epithelial and endothelial cells, are invaded in vivo in each organ. Moreover, a mutant defective for the T3SS-1, Rck and PagN remained able to colonize organs like the wild-type strain and invaded non-phagocytic cells in each organ studied. As the infection of the gall bladder had not previously been described in chicks, invasion of gall bladder cells was confirmed by immunohistochemistry and infection was shown to last several weeks after inoculation. Altogether, for the first time these findings provide insights into cell tropism of Salmonella in relevant organs involved in Salmonella infection in chicks and also demonstrate that the known invasion factors are not required for entry into these cell types.
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Affiliation(s)
- S. M. Roche
- INRAE, Université de Tours, ISP, 37380 Nouzilly, France
| | - S. Holbert
- INRAE, Université de Tours, ISP, 37380 Nouzilly, France
| | - Y. Le Vern
- INRAE, Université de Tours, ISP, 37380 Nouzilly, France
| | - C. Rossignol
- INRAE, Université de Tours, ISP, 37380 Nouzilly, France
| | - A. Rossignol
- INRAE, Université de Tours, ISP, 37380 Nouzilly, France
| | - P. Velge
- INRAE, Université de Tours, ISP, 37380 Nouzilly, France
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13
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Yasin N, Rahman H, Sarwar Y, Qasim M, Nisa I, Ikram A, Zaman G, Khan Z, Mirza MR, Khan N, Safi AUR, Alzahrani KJ. Salmonella Typhi from Northwest Pakistan: Molecular Strain Typing and Drug Resistance Signature. Microb Drug Resist 2021; 28:120-126. [PMID: 34357814 DOI: 10.1089/mdr.2020.0304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Objective: To determine the molecular strain typing and drug resistance pattern of Salmonella enterica serovar Typhi prevalent in Northwest Pakistan. Methodology: A total of 2,138 blood samples of suspected typhoid patients from Northwest Pakistan were collected followed by identification of Salmonella Typhi through biochemical, serological, and species-specific fliC-d gene amplification. These isolates were typed by variable-number tandem repeat (VNTR) profiling and investigated for drug resistance. Results: The overall prevalence of Salmonella Typhi was found to be 8.8% (n = 189). Thirty different VNTR strain types of Salmonella Typhi were detected and the most prevalent strain types were T1 and T4, whereas T27 was less prevalent strain. Among the 189 isolates 175 (92.5%) isolates were multidrug resistant, whereas 12 (5.8%) isolates were extensively drug resistant. Resistance to imipenem in Salmonella Typhi was not observed. Most of the isolates have genes encoding for resistance to fluoroquinolones, including gyrA (n = 164), gyrB (n = 160), parC (n = 164), parE (n = 160), ac(6')-ib-cr (n = 163), qnrS (n = 15), and qnrB (n = 3). Similarly, chloramphinicol (cat; n = 147), azithromycin (msrA; n = 3), and co-trimoxazole (dfrA7; n = 145) resistance genes were detected among Salmonella Typhi isolates. Conclusion: In this study, T1 and T4 type Salmonella Typhi strains were predominantly prevalent in Northwest Pakistan. Antibiotic resistance among Salmonella Typhi isolates were observed. Findings of the study would be helpful to devise an appropriate antibiotic policy to control the emergence of drug-resistant Salmonella Typhi in Pakistan.
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Affiliation(s)
- Nusrat Yasin
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Hazir Rahman
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan.,Department of Microbiology, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Yasra Sarwar
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | - Muhammad Qasim
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Iqbal Nisa
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Aamer Ikram
- Department of Pathology, Armed Forces Institute of Pathology, CMH, Rawalpindi, Pakistan.,National Institute of Health, Islamabad, Pakistan
| | - Gohar Zaman
- Department of Pathology, Armed Forces Institute of Pathology, CMH, Rawalpindi, Pakistan
| | - Zakir Khan
- Institute of Health Sciences, Curkvoa University Adana, Adana, Turkey
| | - Munazza Raza Mirza
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Niamat Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Pakistan
| | - Aziz-Ur-Rehman Safi
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Khalid J Alzahrani
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, Taif University, Taif 21944, Saudi Arabia
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14
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Vashishtha VM, Kalra A. The need & the issues related to new-generation typhoid conjugate vaccines in India. Indian J Med Res 2021; 151:22-34. [PMID: 32134011 PMCID: PMC7055164 DOI: 10.4103/ijmr.ijmr_1890_17] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The low- and middle-income countries bear the highest burden of typhoid fever in the world. India, along with other South Asian countries, has a significant incidence of typhoid fever among young children though there is a paucity of published data on community burden. In spite of the availability of Vi-polysaccharide (Vi-PS) and conjugated Vi-PS vaccines, these are not adequately utilized in India and in the neighbouring countries. To address many shortcomings of the unconjugated Vi-PS vaccines, typhoid conjugate vaccines (TCVs) are developed by conjugating Vi-PS with different carrier proteins. Three such vaccines using tetanus toxoid as a carrier protein are already licensed in India. Several other Vi-PS conjugates are currently in various stages of development. The current review provides an update on the existing and upcoming new TCVs along with a detailed discussion on the various issues involved with their clinical use and limitations.
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Affiliation(s)
| | - Ajay Kalra
- Department of Pediatrics, Sarojini Naidu Medical College, Agra, Uttar Pradesh, India
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15
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Esmailnia E, Amani J, Gargari SLM. Identification of novel vaccine candidate against Salmonella enterica serovar Typhi by reverse vaccinology method and evaluation of its immunization. Genomics 2020; 112:3374-3381. [PMID: 32565239 DOI: 10.1016/j.ygeno.2020.06.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/14/2020] [Accepted: 06/10/2020] [Indexed: 11/17/2022]
Abstract
Salmonella enterica serovar Typhi (S. Typhi) is an essential enteric fever causing bacterium worldwide. Due to the emergence of multidrug-resistant strains, urgently attention is needed to prevent the global spread of them. Vaccination is an alternative approach to control these kinds of infections. Currently available commercial vaccines have significant limitations such as non-recommendation for children below six years of age and poor long-term efficacy. Thus, the development of a new vaccine overcoming these limitations is immediately required. Reverse Vaccinology (RV) is one of the most robust approaches for direct screening of genome sequence assemblies to identify new protein-based vaccines. The present study aimed to identify potential vaccine candidates against S. Typhi by using the RV approach. Immunogenicity of the best candidate against S. Typhi was further investigated. The proteome of S. Typhi strain Ty2 was analyzed to identify the most immunogenic, conserved, and protective surface proteins. Among the predicted vaccine candidates, steD (fimbrial subunit) was the best for qualifying all the applied criteria. The synthetic steD gene was expressed in E.coli, and the mice were immunized with purified recombinant steD protein and then challenged with a lethal dose of S. Typhi. Immunized animals generated high protein-specific antibody titers and demonstrated 70% survival following lethal dose challenge with S. Typhi. Pretreatment of the S. Typhi cells with immunized mice antisera significantly decreased their adhesion to Caco-2 cells. Altogether, steD as a protective antigen could induce a robust and long term and protective immunity in immunized mice against S. Typhi challenge.
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Affiliation(s)
- Ehsan Esmailnia
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | - Jafar Amani
- Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
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16
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Putative β-Barrel Outer Membrane Proteins of the Bovine Digital Dermatitis-Associated Treponemes: Identification, Functional Characterization, and Immunogenicity. Infect Immun 2020; 88:IAI.00050-20. [PMID: 32122940 PMCID: PMC7171239 DOI: 10.1128/iai.00050-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 02/20/2020] [Indexed: 12/25/2022] Open
Abstract
Bovine digital dermatitis (BDD), an infectious disease of the bovine foot with a predominant treponemal etiology, is a leading cause of lameness in dairy and beef herds worldwide. BDD is poorly responsive to antimicrobial therapy and exhibits a relapsing clinical course; an effective vaccine is therefore urgently sought. Using a reverse vaccinology approach, the present study surveyed the genomes of the three BDD-associated Treponema phylogroups for putative β-barrel outer membrane proteins and considered their potential as vaccine candidates. Selection criteria included the presence of a signal peptidase I cleavage site, a predicted β-barrel fold, and cross-phylogroup homology. Four candidate genes were overexpressed in Escherichia coli BL21(DE3), refolded, and purified. Consistent with their classification as β-barrel OMPs, circular-dichroism spectroscopy revealed the adoption of a predominantly β-sheet secondary structure. These recombinant proteins, when screened for their ability to adhere to immobilized extracellular matrix (ECM) components, exhibited a diverse range of ligand specificities. All four proteins specifically and dose dependently adhered to bovine fibrinogen. One recombinant protein was identified as a candidate diagnostic antigen (disease specificity, 75%). Finally, when adjuvanted with aluminum hydroxide and administered to BDD-naive calves using a prime-boost vaccination protocol, these proteins were immunogenic, eliciting specific IgG antibodies. In summary, we present the description of four putative treponemal β-barrel OMPs that exhibit the characteristics of multispecific adhesins. The observed interactions with fibrinogen may be critical to host colonization and it is hypothesized that vaccination-induced antibody blockade of these interactions will impede treponemal virulence and thus be of therapeutic value.
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17
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Wu Y, Hu Q, Dehinwal R, Rakov AV, Grams N, Clemens EC, Hofmann J, Okeke IN, Schifferli DM. The Not so Good, the Bad and the Ugly: Differential Bacterial Adhesion and Invasion Mediated by Salmonella PagN Allelic Variants. Microorganisms 2020; 8:microorganisms8040489. [PMID: 32235448 PMCID: PMC7232170 DOI: 10.3390/microorganisms8040489] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/24/2020] [Accepted: 03/28/2020] [Indexed: 11/21/2022] Open
Abstract
While advances in genomic sequencing have highlighted significant strain variability between and within Salmonella serovars, only a few protein variants have been directly related to evolutionary adaptation for survival, such as host specificity or differential virulence. The current study investigated whether allelic variation of the Salmonella adhesin/invasin PagN influences bacterial interaction with their receptors. The Salmonella enterica, subspecies enterica serovar Typhi (S. Typhi) allelic variant of PagN was found to bind significantly better to different enterocytes as well as to the extracellular matrix protein laminin than did the major Salmonella enterica, subspecies enterica serovar Typhimurium (S. Typhimurium) allele. The two alleles differed at amino acid residues 49 and 109 in two of the four predicted PagN surface loops, and residue substitution analysis revealed that a glutamic acid at residue 49 increased the adhesive and invasive properties of S. Typhi PagN. PagN sequence comparisons from 542 Salmonella strains for six representative S. enterica serovars and S. diarizonae further supported the role of glutamic acid at residues 49 and 109 in optimizing adhesion to cells and laminin, as well as for cell invasion. In summary, this study characterized unique residues in allelic variants of a virulence factor that participates in the colonization and invasive properties of different Salmonella stains, subspecies and serovars.
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Affiliation(s)
- Yanping Wu
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
- College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang Agriculture and Forestry University, Hangzhou 311300, China
| | - Qiaoyun Hu
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
| | - Ruchika Dehinwal
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
| | - Alexey V. Rakov
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
| | - Nicholas Grams
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
| | - Erin C. Clemens
- Department of Biology, Haverford College, Haverford, PA 19041, USA; (E.C.C.); (J.H.); (I.N.O.)
| | - Jennifer Hofmann
- Department of Biology, Haverford College, Haverford, PA 19041, USA; (E.C.C.); (J.H.); (I.N.O.)
| | - Iruka N. Okeke
- Department of Biology, Haverford College, Haverford, PA 19041, USA; (E.C.C.); (J.H.); (I.N.O.)
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan 200284, Oyo State, Nigeria
| | - Dieter M. Schifferli
- Department of Pathobiology, University of Pennsylvania, School of Veterinary Medicine, Philadelphia, PA 19104, USA; (Y.W.); (R.D.); (A.V.R.); (N.G.)
- Correspondence:
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18
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Vinod V, Vijayrajratnam S, Vasudevan AK, Biswas R. The cell surface adhesins of Mycobacterium tuberculosis. Microbiol Res 2019; 232:126392. [PMID: 31841935 DOI: 10.1016/j.micres.2019.126392] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 11/11/2019] [Accepted: 12/07/2019] [Indexed: 02/07/2023]
Abstract
Bacterial cell surface adhesins play a major role in facilitating host colonization and subsequent establishment of infection. The surface of Mycobacterium tuberculosis, owing to the complex architecture of its cell envelope, expresses numerous adhesins with varied chemical nature, including proteins, lipids, lipoproteins, glycoproteins and glycopolymers. Studies on mycobacterial adhesins show that they bind with multifarious host receptors and extracellular matrix (ECM) components. In this review we have highlighted the adhesins that are abundantly present on the mycobacterial surface and their interactions with host receptors. M. tuberculosis interacts with various host cell surface receptors such as toll like receptors, C-type lectin receptors, scavenger receptors, and Fc and complement receptors. Apart from these, ECM components like fibronectin, collagen, elastin, laminin, fibrillin and vitronectin also provide binding sites for surface adhesins of the tubercle bacilli. M. tuberculosis adhesins include proteins with and without signal peptide sequence and transmembrane proteins. Other surface adhesin macromolecules of M. tuberculosis comprises of lipids, glycolipids and glycopolymers. The interaction between the mycobacterial adhesins and their host receptors result in adhesion of the microbe to the host cells, induction of immune response and aid in the pathogenesis of the disease. A thorough understanding of the different M. tuberculosis surface adhesins and host receptors will provide a better picture of interaction between them at molecular level. The information gained on adhesins and host receptors will prove beneficial in developing novel therapeutic strategies such as the use of anti-adhesin molecules to hinder the adhesion of bacteria to the host cells, thereby preventing establishment of infection. The surface molecules discussed in this review will also benefit in identification of new drug targets, diagnostic markers or vaccine candidates against the deadly pathogen.
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Affiliation(s)
- Vivek Vinod
- Center for Nanosciences and Molecular Medicine, Amrita School of Medical Sciences and Research Center (AIMS), Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India
| | - Sukhithasri Vijayrajratnam
- Center for Nanosciences and Molecular Medicine, Amrita School of Medical Sciences and Research Center (AIMS), Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India
| | - Anil Kumar Vasudevan
- Department of Microbiology, Amrita Institute of Medical Sciences and Research Center, Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India
| | - Raja Biswas
- Center for Nanosciences and Molecular Medicine, Amrita School of Medical Sciences and Research Center (AIMS), Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India.
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19
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Dasgupta S, Das S, Biswas A, Bhadra RK, Das S. Small alarmones (p)ppGpp regulate virulence associated traits and pathogenesis of Salmonella enterica serovar Typhi. Cell Microbiol 2019; 21:e13034. [PMID: 31013389 DOI: 10.1111/cmi.13034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/29/2019] [Accepted: 04/17/2019] [Indexed: 12/13/2022]
Abstract
How Salmonella enterica serovar Typhi (S. Typhi), an important human pathogen, survives the stressful microenvironments inside the gastrointestinal tract and within macrophages remains poorly understood. We report here that S. Typhi has a bonafide stringent response (SR) system, which is mediated by (p)ppGpp and regulates multiple virulence-associated traits and the pathogenicity of the S. Typhi Ty2 strain. In an iron overload mouse model of S. Typhi infection, the (p)ppGpp0 (Ty2ΔRelAΔSpoT) strain showed minimal systemic spread and no mortality, as opposed to 100% death of the mice challenged with the isogenic wild-type strain. Ty2ΔRelAΔSpoT had markedly elongated morphology with incomplete septa formation and demonstrated severely attenuated motility and chemotaxis due to the loss of flagella. Absence of the Vi-polysaccharide capsule rendered the mutant strain highly susceptible to complement-mediated lysis. The phenotypes of Ty2ΔRelAΔSpoT was contributed by transcriptional repression of several genes, including fliC, tviA, and ftsZ, as found by reverse transcriptase quantitative polymerase chain reaction and gene complementation studies. Finally, Ty2ΔRelAΔSpoT had markedly reduced invasion into intestinal epithelial cells and significantly attenuated survival within macrophages. To the best of our knowledge, this was the first study that addressed SR in S. Typhi and showed that (p)ppGpp was essential for optimal pathogenic fitness of the organism.
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Affiliation(s)
- Shreya Dasgupta
- Division of Clinical Medicine, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Sayan Das
- Division of Clinical Medicine, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Asim Biswas
- Division of Clinical Medicine, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Rupak K Bhadra
- Infectious Diseases and Immunology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Santasabuj Das
- Division of Clinical Medicine, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
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20
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Das S, Chowdhury R, Pal A, Okamoto K, Das S. Salmonella Typhi outer membrane protein STIV is a potential candidate for vaccine development against typhoid and paratyphoid fever. Immunobiology 2019; 224:371-382. [DOI: 10.1016/j.imbio.2019.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/09/2019] [Accepted: 02/26/2019] [Indexed: 01/07/2023]
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21
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Chowdhury R, Das S, Ta A, Das S. Epithelial invasion by Salmonella Typhi using STIV-Met interaction. Cell Microbiol 2018; 21:e12982. [PMID: 30426648 DOI: 10.1111/cmi.12982] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 11/01/2018] [Accepted: 11/09/2018] [Indexed: 12/20/2022]
Abstract
Typhoid is a life-threatening febrile illness that affects ~24.2 million people worldwide and is caused by the intracellular bacteria Salmonella Typhi (S. Typhi). Intestinal epithelial invasion by S. Typhi is essential for the establishment of successful infection and is traditionally believed to depend on Salmonella pathogenicity island 1-encoded type 3 secretion system 1 (T3SS-1). We had previously reported that bacterial outer membrane protein T2942/STIV functions as a standalone invasin and contributes to the pathogenesis of S. Typhi by promoting epithelial invasion independent of T3SS-1 (Cell Microbiol, 2015). Here, we show that STIV, by using its 20-amino-acid extracellular loop, interacts with receptor tyrosine kinase, Met, of host intestinal epithelial cells. This interaction leads to Met phosphorylation and activation of a downstream signalling cascade, involving Src, phosphatidylinositol 3-kinase/Akt, and Rac1, which culminates into localized actin polymerisation and bacterial engulfment by the cell. Inhibition of Met tyrosine kinase activity severely limited intestinal invasion and systemic infection by S. Typhi in vivo, highlighting the importance of this invasion pathway in disease progression. This is the first report elucidating the mechanism of T3SS-1-independent epithelial invasion of S. Typhi, and this crucial host-pathogen interaction may be targeted therapeutically to restrict pathogenesis.
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Affiliation(s)
- Rimi Chowdhury
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Sayan Das
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Atri Ta
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Santasabuj Das
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, India
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22
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Asadi A, Razavi S, Talebi M, Gholami M. A review on anti-adhesion therapies of bacterial diseases. Infection 2018; 47:13-23. [PMID: 30276540 DOI: 10.1007/s15010-018-1222-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/14/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Infections caused by bacteria are a foremost cause of morbidity and mortality in the world. The common strategy of treating bacterial infections is by local or systemic administration of antimicrobial agents. Currently, the increasing antibiotic resistance is a serious and global problem. Since the most important agent for infection is bacteria attaching to host cells, hence, new techniques and attractive approaches that interfere with the ability of the bacteria to adhere to tissues of the host or detach them from the tissues at the early stages of infection are good therapeutic strategies. METHODS All available national and international databanks were searched using the search keywords. Here, we review various approaches to anti-adhesion therapy, including use of receptor and adhesion analogs, dietary constituents, sublethal concentrations of antibiotics, and adhesion-based vaccines. RESULTS Altogether, the findings suggest that interference with bacterial adhesion serves as a new means to fight infectious diseases. CONCLUSION Anti-adhesion-based therapies can be effective in prevention and treatment of bacterial infections, but further work is needed to elucidate underlying mechanisms.
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Affiliation(s)
- Arezoo Asadi
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Shabnam Razavi
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Malihe Talebi
- Department of Microbiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Gholami
- Department of Microbiology and Virology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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23
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Gawade P, Ghosh P. Genomics driven approach for identification of novel therapeutic targets in Salmonella enterica. Gene 2018; 668:211-220. [DOI: 10.1016/j.gene.2018.05.058] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 05/13/2018] [Accepted: 05/16/2018] [Indexed: 02/06/2023]
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24
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A brief review on the immunological scenario and recent developmental status of vaccines against enteric fever. Vaccine 2017; 35:6359-6366. [DOI: 10.1016/j.vaccine.2017.09.066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/11/2017] [Accepted: 09/22/2017] [Indexed: 02/07/2023]
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25
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Saxena A, Kumar R, Saxena MK. Vaccination with Salmonella Typhi recombinant outer membrane protein 28 induces humoral but non-protective immune response in rabbit. Vet World 2017; 10:946-949. [PMID: 28919688 PMCID: PMC5591484 DOI: 10.14202/vetworld.2017.946-949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 07/13/2017] [Indexed: 11/17/2022] Open
Abstract
Aim: Typhoid is one of the most important food and water borne disease causing millions of deaths over the world. Presently, there is no cost effective vaccine available in India. The outer-membrane proteins (Omps) of Salmonella have been exhibited as a potential candidate for development of subunit vaccine against typhoid. The objective of the present study was to evaluate the use of recombinant Omp 28 protein for immunization of rabbit to elucidate its protection against virulent Salmonella Typhi. Materials and Methods: Immune potential of recombinant Omp28 was tested in New Zealand Rabbits. Rabbits were divided into two groups, i.e., control and test group. Control group was injected with phosphate buffer saline with adjuvant while test group were injected with recombinant Omp28 along with adjuvant. Rabbits were bleed and serum was collected from each rabbit. Serum was tested by Enzyme-linked immunosorbent assay (ELISA) for humoral response. Rabbits were challenged with virulent culture to test the protective immunity. Results: Humoral response was provoked at 15th day and maintained till 30th day. The mean ELISA titer at 15th day was 1 : 28000 (mean titer log 10 : 4.4472) and on the 30th day was 1 : 25866 (mean titer log 10 : 4.4127). Protective immune potential of Omp 28 was assessed by challenge studies in rabbits for which vaccinated and control rabbits were challenged with 109 cells of virulent culture of S. Typhi. In control group, out of six, no rabbit could survive after 48 days while in vaccinated group, three out of six rabbit were survived. Conclusion: Immunization of rabbit with recombinant Omp 28 induced a strong humoral response which was exhibited by high antibody titer in ELISA. Subsequently, intraperitoneal homologous challenge of the immunized New Zealand rabbit resulted in lack of significant protection. These findings indicate that Omp 28 though provoked the humoral immunity but could not provide the protective immunity in rabbit model.
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Affiliation(s)
- Anjani Saxena
- Department of Veterinary Biochemistry and Physiology, College of Veterinary and Animal Sciences, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India
| | - Rajesh Kumar
- Department of Veterinary Microbiology, College of Veterinary and Animal Sciences, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India
| | - Mumtesh Kumar Saxena
- Department of Veterinary Biochemistry and Physiology, College of Veterinary and Animal Sciences, G.B. Pant University of Agriculture and Technology, Pantnagar, Uttarakhand, India
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A recombinant protein of Salmonella Typhi induces humoral and cell-mediated immune responses including memory responses. Vaccine 2017; 35:4523-4531. [PMID: 28739115 DOI: 10.1016/j.vaccine.2017.07.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 06/27/2017] [Accepted: 07/12/2017] [Indexed: 12/23/2022]
Abstract
Gram negative enteric bacteria, Salmonella enterica serovar Typhi (S. Typhi), the etiological agent of typhoid fever is a major public health problem in developing countries. While a permanent solution to the problem would require improved sanitation, food and water hygiene, controlling the infection by vaccination is urgently required due to the emergence of multidrug resistant strains in multiple countries. The currently licensed vaccines are moderately efficacious with limited applicability, and no recommended vaccines exist for younger children. We had previously reported that a candidate vaccine based on recombinant outer membrane protein (rT2544) of S. Typhi is highly immunogenic and protective in mice. Here we show that rT2544-specific antiserum is capable of mediating bacterial lysis by the splenocytes through Antibody-Dependent Cellular Cytotoxicity (ADCC). Increased populations of rT2544-specific IgA and IgG secreting plasma cells are found in the spleen, mesenteric lymph nodes and peyer's patches. Cell-Mediated Immune Responses (CMIR) induced by rT2544 consist of Th1 cell differentiation and generation of cytotoxic T lymphocytes (CTL), which produce IFN-γ and are capable of destroying cells displaying T2544-derived antigens. rT2544 elicits pro-inflammatory cytokines (TNF-α, IL-6) from Bone Marrow-Derived Dendritic cells (BMDCs), while in vitro re-stimulation of rT2544-primed CD4+ T cells induces cell proliferation and generates higher amounts of Th1 cytokines, such as IFN-gamma, TNF-α and IL-2. Finally, the candidate vaccine induces immunological memory in the form of memory B and T lymphocytes. Taken together, the study further supports the potential of rT2544 as a novel and improved vaccine candidate against S. Typhi.
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Innovative Solutions to Sticky Situations: Antiadhesive Strategies for Treating Bacterial Infections. Microbiol Spectr 2017; 4. [PMID: 27227305 DOI: 10.1128/microbiolspec.vmbf-0023-2015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial adherence to host tissue is an essential process in pathogenesis, necessary for invasion and colonization and often required for the efficient delivery of toxins and other bacterial effectors. As existing treatment options for common bacterial infections dwindle, we find ourselves rapidly approaching a tipping point in our confrontation with antibiotic-resistant strains and in desperate need of new treatment options. Bacterial strains defective in adherence are typically avirulent and unable to cause infection in animal models. The importance of this initial binding event in the pathogenic cascade highlights its potential as a novel therapeutic target. This article seeks to highlight a variety of strategies being employed to treat and prevent infection by targeting the mechanisms of bacterial adhesion. Advancements in this area include the development of novel antivirulence therapies using small molecules, vaccines, and peptides to target a variety of bacterial infections. These therapies target bacterial adhesion through a number of mechanisms, including inhibition of pathogen receptor biogenesis, competition-based strategies with receptor and adhesin analogs, and the inhibition of binding through neutralizing antibodies. While this article is not an exhaustive description of every advancement in the field, we hope it will highlight several promising examples of the therapeutic potential of antiadhesive strategies.
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Goswami N, Hussain MI, Borah P. Molecular dynamics approach to probe the antigenicity of PagN - an outer membrane protein of Salmonella Typhi. J Biomol Struct Dyn 2017; 36:2131-2146. [PMID: 28617661 DOI: 10.1080/07391102.2017.1343156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
PagN is a highly immunogenic 27-kDa outer membrane adhesin present in Salmonella Typhi. It plays a major role in the pathogenesis of typhoid fever and has emerged as a strong vaccine candidate. In this report, we predict the three-dimensional structure of PagN and describe the conformational dynamics associated with its four extracellular loops based on two 100-ns molecular dynamics simulations at 300 and 310 K. The formation and deformation of the secondary structures on these loops were also investigated during the simulations which revealed loops L1 and L2 to be highly flexible, whereas the relative flexibility of loops L3 and L4 was minimal. Essential dynamics and principal component analysis deciphered more realistic dynamic behaviours of the loops, particularly at 310 K. Moreover, our epitope predictions suggest that the antigenic peptides for B-cell recognition are located within the loops L1 and L2, while those for T-cell recognition are located within the loops L3 and L4. The binding specificities of the antigenic peptides towards specific human MHC-I and MHC-II HLA alleles closely resembled the stability of the loops L3 and L4 inferred from the simulations. Finally, we identified potential antigenic peptides in the flexible (L1 and L2) as well as stable (L3 and L4) regions of PagN for both B- and T-cell recognitions, which can help in developing effective sub-unit vaccines.
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Affiliation(s)
- Nabajyoti Goswami
- a Bioinformatics Infrastructure Facility , College of Veterinary Science, Assam Agricultural University , Khanapara, Guwahati 781022 , Assam , India
| | - Md Iftikar Hussain
- b State Biotech Hub (Assam), College of Veterinary Science, Assam Agricultural University , Khanapara, Guwahati 781022 , Assam , India
| | - Probodh Borah
- a Bioinformatics Infrastructure Facility , College of Veterinary Science, Assam Agricultural University , Khanapara, Guwahati 781022 , Assam , India.,b State Biotech Hub (Assam), College of Veterinary Science, Assam Agricultural University , Khanapara, Guwahati 781022 , Assam , India
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Ribavirin suppresses bacterial virulence by targeting LysR-type transcriptional regulators. Sci Rep 2016; 6:39454. [PMID: 27991578 PMCID: PMC5171790 DOI: 10.1038/srep39454] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 11/23/2016] [Indexed: 12/30/2022] Open
Abstract
Targeting bacterial virulence mechanisms without compromising bacterial growth is a promising strategy to prevent drug resistance. LysR-type transcriptional regulators (LTTRs) possess structural conservation across bacterial species and regulate virulence in numerous pathogens, making them attractive targets for antimicrobial agents. We targeted AphB, a Vibrio cholerae LTTR, which regulates the expression of genes encoding cholera toxin and toxin-co-regulated pilus for inhibitor designing. Since AphB ligand is unknown, we followed a molecular fragment-based approach for ligand designing using FDA-approved drugs and subsequent screen to identify molecules that exhibited high-affinity binding to AphB ligand-binding pocket. Among the identified compounds, ribavirin, an anti-viral drug, antagonized AphB functions. Ribavirin perturbed Vibrio cholerae pathogenesis in animal models. The inhibitory effects of the drug was limited to the bacteria expressing wild type AphB, but not its constitutively active mutant (AphBN100E), which represents the ligand-bound state, suggesting that ribavirin binds to the active site of AphB to exert its inhibitory role and there exists no AphB-independent mechanism of its action. Similarly, ribavirin suppressed the functions of Salmonella Typhi LTTR Hrg, indicating its broad spectrum efficacy. Moreover, ribavirin did not affect the bacterial viability in culture. This study cites an example of drug repurposing for anti-infective therapy.
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30
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Saha P, Sikdar S, Chakrabarti J, Ghosh M. Response to chemical induced changes and their implication in yfdX proteins. RSC Adv 2016. [DOI: 10.1039/c6ra21913f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Chowdhury R, Mandal RS, Ta A, Das S. An AIL family protein promotes type three secretion system-1-independent invasion and pathogenesis of Salmonella enterica serovar Typhi. Cell Microbiol 2014; 17:486-503. [PMID: 25308535 DOI: 10.1111/cmi.12379] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 09/25/2014] [Accepted: 10/04/2014] [Indexed: 02/05/2023]
Abstract
Adhesion and invasion of Intestinal Epithelial Cells (IECs) are critical for the pathogenesis of Salmonella Typhi, the aetiological agent of human typhoid fever. While type three secretion system-1 (T3SS-1) is a major invasion apparatus of Salmonella, independent invasion mechanisms were described for non-typhoidal Salmonellae. Here, we show that T2942, an AIL-like protein of S. Typhi Ty2 strain, is required for adhesion and invasion of cultured IECs. That invasion was T3SS-1 independent was proved by ectopic expression of T2942 in the non-invasive E. coli BL21 and double-mutant Ty2 (Ty2Δt2942ΔinvG) strains. Laminin and fibronectin were identified as the host-binding partners of T2942 with higher affinity for laminin. Standalone function of T2942 was confirmed by cell adhesion of the recombinant protein, while the protein or anti-T2942 antiserum blocked adhesion/invasion of S. Typhi, indicating specificity. A 20-amino acid extracellular loop was required for invasion, while several loop regions of T2942 contributed to adhesion. Further, T2942 cooperates with laminin-binding T2544 for adhesion and T3SS-1 for invasion. Finally, T2942 was required and synergistically worked with T3SS-1 for pathogenesis of S. Typhi in mice. Considering wide distribution of T2942 among clinical strains, the protein or the 20-mer peptide may be suitable for vaccine development.
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Affiliation(s)
- Rimi Chowdhury
- Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, P-33 Scheme XM C.I.T. Road, Beliaghata Kolkata, 700010, India
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An inducible and secreted eukaryote-like serine/threonine kinase of Salmonella enterica serovar Typhi promotes intracellular survival and pathogenesis. Infect Immun 2014; 83:522-33. [PMID: 25404028 DOI: 10.1128/iai.02521-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Eukaryote-like serine/threonine kinases (eSTKs) constitute an important family of bacterial virulence factors. Genome analysis had predicted putative eSTKs in Salmonella enterica serovar Typhi, although their functional characterization and the elucidation of their role in pathogenesis are still awaited. We show here that the primary sequence and secondary structure of the t4519 locus of Salmonella Typhi Ty2 have all the signatures of eukaryotic superfamily kinases. t4519 encodes a ∼39-kDa protein (T4519), which shows serine/threonine kinase activities in vitro. Recombinant T4519 (rT4519) is autophosphorylated and phosphorylates the universal substrate myelin basic protein. Infection of macrophages results in decreased viability of the mutant (Ty2Δt4519) strain, which is reversed by gene complementation. Moreover, reactive oxygen species produced by the macrophages signal to the bacteria to induce T4519, which is translocated to the host cell cytoplasm. That T4519 may target a host substrate(s) is further supported by the activation of host cellular signaling pathways and the induction of cytokines/chemokines. Finally, the role of T4519 in the pathogenesis of Salmonella Typhi is underscored by the significantly decreased mortality of mice infected with the Ty2Δt4519 strain and the fact that the competitive index of this strain for causing systemic infection is 0.25% that of the wild-type strain. This study characterizes the first eSTK of Salmonella Typhi and demonstrates its role in promoting phagosomal survival of the bacteria within macrophages, which is a key determinant of pathogenesis. This, to the best of our knowledge, is the first study to describe the essential role of eSTKs in the in vivo pathogenesis of Salmonella spp.
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Dougan G, Baker S. Salmonella entericaSerovar Typhi and the Pathogenesis of Typhoid Fever. Annu Rev Microbiol 2014; 68:317-36. [DOI: 10.1146/annurev-micro-091313-103739] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Gordon Dougan
- The Wellcome Trust Sanger Institute, The Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom;
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Program, Oxford University, Clinical Research Unit, Ho Chi Minh City, Vietnam;
- Centre for Tropical Medicine, Oxford University, Oxford OX3 7FZ, United Kingdom
- The London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom
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Dhal PK, Barman RK, Saha S, Das S. Dynamic modularity of host protein interaction networks in Salmonella Typhi infection. PLoS One 2014; 9:e104911. [PMID: 25144185 PMCID: PMC4140748 DOI: 10.1371/journal.pone.0104911] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/17/2014] [Indexed: 01/08/2023] Open
Abstract
Background Salmonella Typhi is a human-restricted pathogen, which causes typhoid fever and remains a global health problem in the developing countries. Although previously reported host expression datasets had identified putative biomarkers and therapeutic targets of typhoid fever, the underlying molecular mechanism of pathogenesis remains incompletely understood. Methods We used five gene expression datasets of human peripheral blood from patients suffering from S. Typhi or other bacteremic infections or non-infectious disease like leukemia. The expression datasets were merged into human protein interaction network (PIN) and the expression correlation between the hubs and their interacting proteins was measured by calculating Pearson Correlation Coefficient (PCC) values. The differences in the average PCC for each hub between the disease states and their respective controls were calculated for studied datasets. The individual hubs and their interactors with expression, PCC and average PCC values were treated as dynamic subnetworks. The hubs that showed unique trends of alterations specific to S. Typhi infection were identified. Results We identified S. Typhi infection-specific dynamic subnetworks of the host, which involve 81 hubs and 1343 interactions. The major enriched GO biological process terms in the identified subnetworks were regulation of apoptosis and biological adhesions, while the enriched pathways include cytokine signalling in the immune system and downstream TCR signalling. The dynamic nature of the hubs CCR1, IRS2 and PRKCA with their interactors was studied in detail. The difference in the dynamics of the subnetworks specific to S. Typhi infection suggests a potential molecular model of typhoid fever. Conclusions Hubs and their interactors of the S. Typhi infection-specific dynamic subnetworks carrying distinct PCC values compared with the non-typhoid and other disease conditions reveal new insight into the pathogenesis of S. Typhi.
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Affiliation(s)
- Paltu Kumar Dhal
- Biomedical Informatics Centre, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
| | - Ranjan Kumar Barman
- Biomedical Informatics Centre, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
| | - Sudipto Saha
- Bioinformatics Centre, Bose Institute, Kolkata, West Bengal, India
| | - Santasabuj Das
- Biomedical Informatics Centre, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India; Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
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Description of a novel adhesin of Mycobacterium avium subsp. paratuberculosis. BIOMED RESEARCH INTERNATIONAL 2014; 2014:729618. [PMID: 25136616 PMCID: PMC4130151 DOI: 10.1155/2014/729618] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 06/29/2014] [Indexed: 12/12/2022]
Abstract
The binding and ingestion of Mycobacterium avium subsp. paratuberculosis (MAP) by host cells are fibronectin (FN) dependent. In several species of mycobacteria, a specific family of proteins allows the attachment and internalization of these bacteria by epithelial cells through interaction with FN. Thus, the identification of adhesion molecules is essential to understand the pathogenesis of MAP. The aim of this study was to identify and characterize FN binding cell wall proteins of MAP. We searched for conserved adhesins within a large panel of surface immunogenic proteins of MAP and investigated a possible interaction with FN. For this purpose, a cell wall protein fraction was obtained and resolved by 2D electrophoresis. The immunoreactive spots were identified by MALDI-TOF MS and a homology search was performed. We selected elongation factor Tu (EF-Tu) as candidate for further studies. We demonstrated the FN-binding capability of EF-Tu using a ligand blot assay and also confirmed the interaction with FN in a dose-dependent manner by ELISA. The dissociation constant of EF-Tu was determined by surface plasmon resonance and displayed values within the μM range. These data support the hypothesis that this protein could be involved in the interaction of MAP with epithelial cells through FN binding.
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Krachler AM, Orth K. Targeting the bacteria-host interface: strategies in anti-adhesion therapy. Virulence 2014; 4:284-94. [PMID: 23799663 PMCID: PMC3710331 DOI: 10.4161/viru.24606] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Bacterial infections are a major cause of morbidity and mortality worldwide and are increasingly problematic to treat due to the rise in antibiotic-resistant strains. It becomes more and more challenging to develop new antimicrobials that are able to withstand the ever-increasing repertoire of bacterial resistance mechanisms. This necessitates the development of alternative approaches to prevent and treat bacterial infections. One of the first steps during bacterial infection is adhesion of the pathogen to host cells. A pathogen’s ability to colonize and invade host tissues strictly depends on this process. Thus, interference with adhesion (anti-adhesion therapy) is an efficient way to prevent or treat bacterial infections. As a basis to present different strategies to interfere with pathogen adhesion, this review briefly introduces general concepts of bacterial attachment to host cells. We further discuss advantages and disadvantages of anti-adhesion treatments and issues that are in need of improvement so as to make anti-adhesion compounds a more broadly applicable alternative to conventional antimicrobials.
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Affiliation(s)
- Anne Marie Krachler
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, UK
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37
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Hayward MR, Jansen VAA, Woodward MJ. Comparative genomics of Salmonella enterica serovars Derby and Mbandaka, two prevalent serovars associated with different livestock species in the UK. BMC Genomics 2013; 14:365. [PMID: 23725633 PMCID: PMC3680342 DOI: 10.1186/1471-2164-14-365] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/27/2013] [Indexed: 01/06/2023] Open
Abstract
Background Despite the frequent isolation of Salmonella enterica sub. enterica serovars Derby and Mbandaka from livestock in the UK and USA little is known about the biological processes maintaining their prevalence. Statistics for Salmonella isolations from livestock production in the UK show that S. Derby is most commonly associated with pigs and turkeys and S. Mbandaka with cattle and chickens. Here we compare the first sequenced genomes of S. Derby and S. Mbandaka as a basis for further analysis of the potential host adaptations that contribute to their distinct host species distributions. Results Comparative functional genomics using the RAST annotation system showed that predominantly mechanisms that relate to metabolite utilisation, in vivo and ex vivo persistence and pathogenesis distinguish S. Derby from S. Mbandaka. Alignment of the genome nucleotide sequences of S. Derby D1 and D2 and S. Mbandaka M1 and M2 with Salmonella pathogenicity islands (SPI) identified unique complements of genes associated with host adaptation. We also describe a new genomic island with a putative role in pathogenesis, SPI-23. SPI-23 is present in several S. enterica serovars, including S. Agona, S. Dublin and S. Gallinarum, it is absent in its entirety from S. Mbandaka. Conclusions We discovered a new 37 Kb genomic island, SPI-23, in the chromosome sequence of S. Derby, encoding 42 ORFS, ten of which are putative TTSS effector proteins. We infer from full-genome synonymous SNP analysis that these two serovars diverged, between 182kya and 625kya coinciding with the divergence of domestic pigs. The differences between the genomes of these serovars suggest they have been exposed to different stresses including, phage, transposons and prolonged externalisation. The two serovars possess distinct complements of metabolic genes; many of which cluster into pathways for catabolism of carbon sources.
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Affiliation(s)
- Matthew R Hayward
- Animal Health and Veterinary Laboratories Agency, Woodham Lane, New Haw, Addlestone, Surrey, UK.
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38
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Cozens D, Read RC. Anti-adhesion methods as novel therapeutics for bacterial infections. Expert Rev Anti Infect Ther 2013; 10:1457-68. [PMID: 23253323 DOI: 10.1586/eri.12.145] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Anti-adhesion therapies for bacterial infections offer an alternative to antibiotics, with those therapies bacteria are not killed but are prevented from causing harm to a host by inhibiting adherence to host cells and tissues, a prerequisite for the majority of infectious diseases. The mechanisms of these potential therapeutic agents include inhibition of adhesins and their host receptors, vaccination with adhesins or analogs, use of probiotics and dietary supplements that interfere with receptor-adhesin interactions, subminimal inhibitory concentrations of antibiotics and manipulation of hydrophobic interactions. Once developed, these drugs will contribute to the arsenal for fighting infectious disease in the future, potentially subverting antibiotic resistance.
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Affiliation(s)
- Daniel Cozens
- Department of Infection & Immunity, K Floor, Royal Hallamshire Hospital, Sheffield School of Medicine & Biomedical Science, University of Sheffield, Sheffield, S10 3JF, UK
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Yang Y, Wan C, Xu H, Wei H. Identification and characterization of OmpL as a potential vaccine candidate for immune-protection against salmonellosis in mice. Vaccine 2013; 31:2930-6. [PMID: 23643894 DOI: 10.1016/j.vaccine.2013.04.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 04/11/2013] [Accepted: 04/18/2013] [Indexed: 01/13/2023]
Abstract
Salmonella is gram-negative flagellated bacteria that can cause food and waterborne gastroenteritis and typhoid fever in humans. Despite the importance of Salmonella infections in human and animal health, the target antigens of Salmonella-specific immunity remain poorly defined, the effectiveness of the currently available vaccines is also limited. Outer membrane proteins (OMPs) of Salmonella have been considered possible candidates for conferring protection against salmonellosis. OMPs interface the cell with the environment, thus representing important potential vaccine candidate for pathogen infection. We showed that the outer membrane porin L (OmpL) is a transmembrane β barrel (TMBB) protein, which forms 12 transmembrane β-strands. OmpL of S. Typhimurium is highly immunogenic, OmpL could evoke humoral and cell-mediated immune responses, and confer 100% protection to immunized mice against challenge with very high doses of S. Typhimurium. Besides, very efficient clearance of bacteria from the reticuloendothelial systems of immunized mice was seen. The homology search further revealed that OmpL is widely distributed and conserved, homologous proteins were identified in S. Typhi and Paratyphi by RT-PCR and western blot. We also found that anti-rOmpL serum harber a high bactericidal activity for Salmonella serovars tested in this study. Therefore, OmpL provide a promising target for the development of a candidate vaccine against Salmonella infection.
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Affiliation(s)
- Youjun Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China
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Yang Y, Wan C, Xu H, Aguilar ZP, Tan Q, Xu F, Lai W, Xiong Y, Wei H. Identification of an outer membrane protein of Salmonella enterica serovar Typhimurium as a potential vaccine candidate for Salmonellosis in mice. Microbes Infect 2013; 15:388-98. [PMID: 23485513 DOI: 10.1016/j.micinf.2013.02.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2012] [Revised: 02/10/2013] [Accepted: 02/18/2013] [Indexed: 12/27/2022]
Abstract
We report our investigation of the functions of PagN in Salmonella pathogenesis and its potential as a vaccine candidate. Further investigation conducted in this study indicates that the outer membrane protein PagN is important for Salmonella adhesion/invasion of epithelial cells as well as bacterial virulence. When pagN was deleted from Salmonella enterica serovar Typhimurium (S. Typhimurium), the adhesion and invasion of HT-29 epithelial cells was significantly decreased compared with the wild type strain. Mice infected with the pagN mutant strain exhibited less pathological signs in the intestine and survived longer than the wild-type-infected mice. PagN is widely distributed and conserved among clinical isolates of different Salmonella serovars, making PagN a potential vaccine candidate for Salmonella infection. To elucidate the potential of PagN as a vaccine, we expressed and purified recombinant PagN (rPagN). When rPagN was tested in mice, it provided significant protection against Salmonella infection in vivo. In vitro, anti-PagN serum enhanced clearance of Salmonella, indicating a contribution of PagN-specific antibodies to the killing process. This correlates well with the observed protection of mice immunized with rPagN. Our preliminary results indicate more functions of PagN in S. Typhimurium virulence as well as its potential as a protective vaccine.
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Affiliation(s)
- Youjun Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, 235 Nanjing East Road, Nanchang 330047, PR China
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Vi antigen of Salmonella enetrica serovar Typhi — biosynthesis, regulation and its use as vaccine candidate. Open Life Sci 2012. [DOI: 10.2478/s11535-012-0082-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractVi capsular polysaccharide (Vi antigen) was first identified as the virulence antigen of Salmonella enterica serovar Typhi (S. Typhi), the causative agent of typhoid fever in humans. The presence of Vi antigen differentiates S. Typhi from other serovars of Salmonella. Vi antigen is a linear polymer consisting of α-1,4-linked-N-acetyl-galactosaminuronate, whose expression is controlled by three chromosomal loci, namely viaA, viaB and ompB. Both viaA and viaB region are present on Salmonella Pathogenicity Island-7, a large, mosaic, genetic island. The viaA region encodes a positive regulator and the viaB locus is composed of 11 genes designated tviA-tviE (for Vi biosyhthesis), vexA-vexE (for Vi antigen export) and ORF 11. Vi polysaccharide is synthesized from UDP-N-acetyl glucosamine in a series of steps requiring TviB, TviC, and TviE, and regulation of Vi polysaccharide synthesis is controlled by two regulatory systems, rscB-rscC (viaA locus) and ompR-envZ (ompB locus), which respond to changes in osmolarity. This antigen is highly immunogenic and has been used for the formulation of one of the currently available vaccines against typhoid. Despite advancement in the area of vaccinology, its pace of progress needs to be accelerated and effective control programmes will be needed for proper disease management.
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42
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Singh B, Fleury C, Jalalvand F, Riesbeck K. Human pathogens utilize host extracellular matrix proteins laminin and collagen for adhesion and invasion of the host. FEMS Microbiol Rev 2012; 36:1122-80. [PMID: 22537156 DOI: 10.1111/j.1574-6976.2012.00340.x] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Revised: 02/08/2012] [Accepted: 03/29/2012] [Indexed: 01/11/2023] Open
Abstract
Laminin (Ln) and collagen are multifunctional glycoproteins that play an important role in cellular morphogenesis, cell signalling, tissue repair and cell migration. These proteins are ubiquitously present in tissues as a part of the basement membrane (BM), constitute a protective layer around blood capillaries and are included in the extracellular matrix (ECM). As a component of BMs, both Lns and collagen(s), thus function as major mechanical containment molecules that protect tissues from pathogens. Invasive pathogens breach the basal lamina and degrade ECM proteins of interstitial spaces and connective tissues using various ECM-degrading proteases or surface-bound plasminogen and matrix metalloproteinases recruited from the host. Most pathogens associated with the respiratory, gastrointestinal, or urogenital tracts, as well as with the central nervous system or the skin, have the capacity to bind and degrade Lns and collagen(s) in order to adhere to and invade host tissues. In this review, we focus on the adaptability of various pathogens to utilize these ECM proteins as enhancers for adhesion to host tissues or as a targets for degradation in order to breach the cellular barriers. The major pathogens discussed are Streptococcus, Staphylococcus, Pseudomonas, Salmonella, Yersinia, Treponema, Mycobacterium, Clostridium, Listeria, Porphyromonas and Haemophilus; Candida, Aspergillus, Pneumocystis, Cryptococcus and Coccidioides; Acanthamoeba, Trypanosoma and Trichomonas; retrovirus and papilloma virus.
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Affiliation(s)
- Birendra Singh
- Medical Microbiology, Department of Laboratory Medicine Malmö, Skåne University Hospital, Lund University, Malmö, Sweden
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Hoque KM, Chakraborty S, Sheikh IA, Woodward OM. New advances in the pathophysiology of intestinal ion transport and barrier function in diarrhea and the impact on therapy. Expert Rev Anti Infect Ther 2012; 10:687-699. [DOI: 10.1586/eri.12.47] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Chauhan DS, Chandra S, Gupta A, Singh TR. Molecular modelling, docking and interaction studies of human-plasmogen and salmonella enolase with enolase inhibitors. Bioinformation 2012; 8:185-8. [PMID: 22419838 PMCID: PMC3301999 DOI: 10.6026/97320630008185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 02/11/2012] [Indexed: 11/23/2022] Open
Abstract
Salmonella enteric serovar Typhi Ty2 is a human specific pathogen and an etiological agent for typhoid fever. Most of Salmonella serotypes produce glycogen which has a comparatively minor role in virulence and colonization, but has a more significant role in survival. Enzymes present in glycolytic pathway of bacteria help bacteria to survive by activating other factors inside host. Numerous pathogenic bacteria species intervene with the plasminogen system, and this plasminogen-enolase association may play a critical role in the virulence of S. Typhi by causing direct damage to the host cell extracellular matrix, possibly by enzymic degradation of extracellular matrix proteins or other protein constituents. In this study, molecular modelling of enolase of Salmonella has been accomplished in silico by comparative modelling; we have then analyzed Human alpha enolase which is a homodimer and serves on epithelial cells with our model. Both Structures were docked by D-tartronate semialdehyde phosphate (TSP) and 3-aminoenolpyruvate phosphate (AEP) enolase inhibitors. Our study shows that salmonella enolase and human enolase have different active sites in their structure. This will help in development of new ligands, more suitable for inhibiting bacterial survival inside host as vaccines for typhoid fever are not fully protective. The study also confirmed that enolase Salmonella and Human Plasminogen suggested direct physical interaction between both of them as the activation loop of plasminogen residues showed conformational changes similar to the tissue type plasminogen activator. Various computational biology tools were used for our present study such as Modeller, Molegro Virtual Docker, Grommacs.
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Affiliation(s)
- Digvijay Singh Chauhan
- Bioinformatics Sub-Centre, School of Biotechnology, Devi Ahilya University, Indore-452001
| | - Sharat Chandra
- Bioinformatics Sub-Centre, School of Biotechnology, Devi Ahilya University, Indore-452001
| | - Arun Gupta
- School of Computer Science and
Information Technology, Devi Ahilya University, Indore-452001
| | - Tiratha Raj Singh
- Bioinformatics Sub-Centre, School of Biotechnology, Devi Ahilya University, Indore-452001
- Dpartment of Biotechnology and Bioinformatics, Jaypee
University of Information Technology, Waknaghat, Solan-173234, H.P, India
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Khoo SK, Petillo D, Parida M, Tan AC, Resau JH, Obaro SK. Host response transcriptional profiling reveals extracellular components and ABC (ATP-binding cassette) transporters gene enrichment in typhoid fever-infected Nigerian children. BMC Infect Dis 2011; 11:241. [PMID: 21914192 PMCID: PMC3189140 DOI: 10.1186/1471-2334-11-241] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 09/13/2011] [Indexed: 12/18/2022] Open
Abstract
Background Salmonella enterica serovar Typhi (S. Typhi) is a human-specific pathogen that causes typhoid fever, and remains a global health problem especially in developing countries. Its pathogenesis is complex and host response is poorly understood. In Africa, typhoid fever can be a major cause of morbidity in young infected children. The onset of the illness is insidious and clinical diagnosis is often unreliable. Gold standard blood culture diagnostic services are limited, thus rapid, sensitive, and affordable diagnostic test is essential in poor-resourced clinical settings. Routine typhoid fever vaccination is highly recommended but currently licensed vaccines provide only 55-75% protection. Recent epidemiological studies also show the rapid emergence of multi-drug resistant S. Typhi strains. High-throughput molecular technologies, such as microarrays, can dissect the molecular mechanisms of host responses which are S. Typhi-specific to provide a comprehensive genomic component of immunological responses and suggest new insights for diagnosis and treatment. Methods Global transcriptional profiles of S. Typhi-infected young Nigerian children were obtained from their peripheral blood and compared with that of other bacteremic infections using Agilent gene expression microarrays. The host-response profiles of the same patients in acute vs. convalescent phases were also determined. The top 96-100 differentially-expressed genes were identified and four genes were validated by quantitative real-time PCR. Gene clusters were obtained and functional pathways were predicted by DAVID (Database for Annotation, Visualization and Integrated Discovery). Results Transcriptional profiles from S. Typhi-infected children could be distinguished from those of other bacteremic infections. Enriched gene clusters included genes associated with extracellular peptides/components such as lipocalin (LCN2) and systemic immune response which is atypical in bacterial invasion. Distinct gene expression profiles can also be obtained from acute vs. convalescent phase during typhoid fever infection. We found novel down-regulation of ABC (ATP-binding cassette) transporters genes such as ABCA7, ABCC5, and ABCD4 and ATPase activity as the highest enriched pathway. Conclusions We identified unique extracellular components and ABC transporters gene enrichments in typhoid fever-infected Nigerian children, which have never been reported. These enriched gene clusters may represent novel targeted pathways to improve diagnostic, prognostic, therapeutic and next-generation vaccine strategies for typhoid fever in Africa.
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Affiliation(s)
- Sok Kean Khoo
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, East Lansing, MI, USA.
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The heat-resistant agglutinin family includes a novel adhesin from enteroaggregative Escherichia coli strain 60A. J Bacteriol 2011; 193:4813-20. [PMID: 21764925 DOI: 10.1128/jb.05142-11] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Heat-resistant agglutinin 1 (Hra1) is an accessory colonization factor of enteroaggregative Escherichia coli (EAEC) strain 042. Tia, a close homolog of Hra1, is an invasin and adhesin that has been described in enterotoxigenic E. coli. We devised a PCR-restriction fragment length polymorphism screen for the associated genes and found that they occur among 55 (36.7%) of the enteroaggregative E. coli isolates screened, as well as lower proportions of enterotoxigenic, enteropathogenic, enterohemorrhagic, and commensal E. coli isolates. Overall, 25%, 8%, and 3% of 150 EAEC strains harbored hra1 alone, tia alone, or both genes, respectively. One EAEC isolate, 60A, produced an amplicon with a unique restriction profile, distinct from those of hra1 and tia. We cloned and sequenced the full-length agglutinin gene from strain 60A and have designated it hra2. The hra2 gene was not detected in any of 257 diarrheagenic E. coli isolates in our collection but is present in the genome of Salmonella enterica serovar Heidelberg strain SL476. The cloned hra2 gene from strain 60A, which encodes a predicted amino acid sequence that is 64% identical to that of Hra1 and 68% identical to that of Tia, was sufficient to confer adherence on E. coli K-12. We constructed an hra2 deletion mutant of EAEC strain 60A. The mutant was deficient in adherence but not autoaggregation or invasion, pointing to a functional distinction from the autoagglutinin Hra1 and the Tia invasin. Hra1, Tia, and the novel accessory adhesin Hra2 are members of a family of integral outer membrane proteins that confer different colonization-associated phenotypes.
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