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Lau YT, Tan HS. Acinetobacter baumannii subunit vaccines: recent progress and challenges. Crit Rev Microbiol 2024; 50:434-449. [PMID: 37211625 DOI: 10.1080/1040841x.2023.2215303] [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: 01/16/2023] [Revised: 03/28/2023] [Accepted: 05/12/2023] [Indexed: 05/23/2023]
Abstract
Acinetobacter baumannii is a Gram-negative, opportunistic pathogen that causes nosocomial infection with a high mortality rate in immunocompromised individuals. With the frequent emergence of multidrug-resistant A. baumannii strains that have rapidly gained resistance to most antibiotics, an extensive search for an effective A. baumannii vaccine is ongoing. Over the decade, many subunit vaccine candidates were identified using reverse vaccinology and in vivo animal studies for validation. Nineteen subunit vaccine candidates with a wide range of efficacy, from 14% to 100% preclinical survival rates, were included in this review. This article provides an updated review of several outer membrane proteins (Omp) that emerged as vaccine candidates with great potential, including OmpA, Omp34, Omp22 and BamA, based on their high conservancy, antigenicity, and immune protection against A. baumannii infection. However, there is still no licenced A. baumannii vaccine currently due to several practical issues that have yet to be resolved, such as inconsistencies between validation studies, antigen variability and insolubility. Moving forward, much investigation and innovation are still required to tackle these challenges for the regulatory approval of an A. baumannii subunit vaccine, including standardisation of immunisation study parameters, improving antigen solubility and the incorporation of nucleic acid vaccine technology.
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Affiliation(s)
- Yi Teng Lau
- School of Science, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Hock Siew Tan
- School of Science, Monash University Malaysia, Bandar Sunway, Malaysia
- Tropical Medicine and Biology Multidisciplinary Platform, Monash University Malaysia, Bandar Sunway, Malaysia
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Jeffreys S, Tompkins MP, Aki J, Papp SB, Chambers JP, Guentzel MN, Hung CY, Yu JJ, Arulanandam BP. Development and Evaluation of an Immunoinformatics-Based Multi-Peptide Vaccine against Acinetobacter baumannii Infection. Vaccines (Basel) 2024; 12:358. [PMID: 38675740 PMCID: PMC11054912 DOI: 10.3390/vaccines12040358] [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: 02/27/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/28/2024] Open
Abstract
Multi-drug-resistant (MDR) Acinetobacter baumannii is an opportunistic pathogen associated with hospital-acquired infections. Due to its environmental persistence, virulence, and limited treatment options, this organism causes both increased patient mortality and incurred healthcare costs. Thus, prophylactic vaccination could be ideal for intervention against MDR Acinetobacter infection in susceptible populations. In this study, we employed immunoinformatics to identify peptides containing both putative B- and T-cell epitopes from proteins associated with A. baumannii pathogenesis. A novel Acinetobacter Multi-Epitope Vaccine (AMEV2) was constructed using an A. baumannii thioredoxin A (TrxA) leading protein sequence followed by five identified peptide antigens. Antisera from A. baumannii infected mice demonstrated reactivity to rAMEV2, and subcutaneous immunization of mice with rAMEV2 produced high antibody titer against the construct as well as peptide components. Immunization results in increased frequency of IL-4-secreting splenocytes indicative of a Th2 response. AMEV2-immunized mice were protected against intranasal challenge with a hypervirulent strain of A. baumannii and demonstrated reduced bacterial burden at 48 h. In contrast, all mock vaccinated mice succumbed to infection within 3 days. Results presented here provide insight into the effectiveness of immunoinformatic-based vaccine design and its potential as an effective strategy to combat the rise of MDR pathogens.
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Affiliation(s)
- Sean Jeffreys
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
| | - Megan P. Tompkins
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
| | - Jadelynn Aki
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
| | - Sara B. Papp
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
| | - James P. Chambers
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
| | - M. Neal Guentzel
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
| | - Chiung-Yu Hung
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
| | - Jieh-Juen Yu
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
| | - Bernard P. Arulanandam
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX 78249, USA; (S.J.); (M.P.T.); (J.A.); (J.P.C.); (M.N.G.); (C.-Y.H.)
- Department of Immunology, Tufts University School of Medicine, Boston, MA 02111, USA
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Heidarinia H, Tajbakhsh E, Rostamian M, Momtaz H. Two peptides derivate from Acinetobacter baumannii outer membrane protein K as vaccine candidates: a comprehensive in silico study. BMC Res Notes 2023; 16:128. [PMID: 37391796 DOI: 10.1186/s13104-023-06409-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 06/20/2023] [Indexed: 07/02/2023] Open
Abstract
BACKGROUND The lack of appropriate vaccines is an obstacle to the effective management of A. baumannii infections. Peptide vaccines offer an attractive and promising preventive strategy against A. baumannii. OBJECTIVE In this study, we identified specific T cell epitopes of A. baumannii outer membrane protein K (OMPK) using comprehensive bioinformatics and detailed molecular docking analysis. METHODS Both class-I and class-II T cell epitopes of A. baumannii OMPK were predicted by three tools namely IEDB, SYFPEITHI, and ProPred. The predicted epitopes were shortlisted based on several analyses including prediction scoring, clustering, exclusion of human similarity, considering immunogenicity and cytokine production, and removal of toxic and/or allergen epitopes. The epitopic peptides with high prediction scores and appropriate properties containing both class-I and class-II T cell epitopes were selected. Two of these class I/II epitopic peptides were chosen for molecular docking studies and assessing their physicochemical properties as vaccine candidates. RESULTS The results showed many T-cell epitopes of OMPK that could be evaluated for possible immunogenicity. Two of these epitopes (containing both class-I and II epitopes) had high prediction scores, were predicted by several tools, attached to several HLAs, and had the best docking score. They had different physicochemical properties and were conserved among Acinetobacter species. DISCUSSION We identified the A. baumannii OMPK high immunogenic class-I and class-II T cell epitopes and introduced two promising high immunogenic peptides as vaccine candidates. It is recommended to perform in vitro/in vivo investigation of these peptides to determine their true efficacy and efficiency.
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Affiliation(s)
- Hana Heidarinia
- Department of Microbiology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Elahe Tajbakhsh
- Department of Microbiology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
| | - Mosayeb Rostamian
- Infectious Diseases Research Center, Health Institute, Kermanshah University of Medical Sciences, Imam Reza Hospital, Parastar Blvd, Kermanshah, 6714415333, Iran.
| | - Hassan Momtaz
- Department of Microbiology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
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Hu Y, Zhang X, Deng S, Yue C, Jia X, Lyu Y. Non-antibiotic prevention and treatment against Acinetobacter baumannii infection: Are vaccines and adjuvants effective strategies? Front Microbiol 2023; 14:1049917. [PMID: 36760499 PMCID: PMC9905804 DOI: 10.3389/fmicb.2023.1049917] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/09/2023] [Indexed: 01/26/2023] Open
Abstract
Acinetobacter baumannii (A. baumannii) is a Gram-negative opportunistic pathogen widely attached to the surface of medical instruments, making it one of the most common pathogens of nosocomial infection, and often leading to cross-infection and co-infection. Due to the extensive antibiotic and pan-resistance, A. baumannii infection is facing fewer treatment options in the clinic. Therefore, the prevention and treatment of A. baumannii infection have become a tricky global problem. The requirement for research and development of the new strategy is urgent. Now, non-antibiotic treatment strategies are urgently needed. This review describes the research on A. baumannii vaccines and antibacterial adjuvants, discusses the advantages and disadvantages of different candidate vaccines tested in vitro and in vivo, especially subunit protein vaccines, and shows the antibacterial efficacy of adjuvant drugs in monotherapy.
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Affiliation(s)
- Yue Hu
- Yan'an Key Laboratory of Microbial Drug Innovation and Transformation, School of Basic Medicine, Yan'an University, Yan'An, China,Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, China
| | - Xianqin Zhang
- School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China
| | - Shanshan Deng
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, China,School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China
| | - Changwu Yue
- Yan'an Key Laboratory of Microbial Drug Innovation and Transformation, School of Basic Medicine, Yan'an University, Yan'An, China,*Correspondence: Changwu Yue ✉
| | - Xu Jia
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, China,School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China,Xu Jia ✉
| | - Yuhong Lyu
- Yan'an Key Laboratory of Microbial Drug Innovation and Transformation, School of Basic Medicine, Yan'an University, Yan'An, China,Yuhong Lyu ✉
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Yang N, Jin X, Zhu C, Gao F, Weng Z, Du X, Feng G. Subunit vaccines for Acinetobacter baumannii. Front Immunol 2023; 13:1088130. [PMID: 36713441 PMCID: PMC9878323 DOI: 10.3389/fimmu.2022.1088130] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 12/22/2022] [Indexed: 01/15/2023] Open
Abstract
Acinetobacter baumannii is a gram-negative bacterium and a crucial opportunistic pathogen in hospitals. A. baumannii infection has become a challenging problem in clinical practice due to the increasing number of multidrug-resistant strains and their prevalence worldwide. Vaccines are effective tools to prevent and control A. baumannii infection. Many researchers are studying subunit vaccines against A. baumannii. Subunit vaccines have the advantages of high purity, safety, and stability, ease of production, and highly targeted induced immune responses. To date, no A. baumannii subunit vaccine candidate has entered clinical trials. This may be related to the easy degradation of subunit vaccines in vivo and weak immunogenicity. Using adjuvants or delivery vehicles to prepare subunit vaccines can slow down degradation and improve immunogenicity. The common immunization routes include intramuscular injection, subcutaneous injection, intraperitoneal injection and mucosal vaccination. The appropriate immunization method can also enhance the immune effect of subunit vaccines. Therefore, selecting an appropriate adjuvant and immunization method is essential for subunit vaccine research. This review summarizes the past exploration of A. baumannii subunit vaccines, hoping to guide current and future research on these vaccines.
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Affiliation(s)
- Ning Yang
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiao Jin
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chenghua Zhu
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Fenglin Gao
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zheqi Weng
- The Second Clinical Medical School of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xingran Du
- Department of Infectious Disease, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China,*Correspondence: Xingran Du, ; Ganzhu Feng,
| | - Ganzhu Feng
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China,*Correspondence: Xingran Du, ; Ganzhu Feng,
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Fereshteh S, Ajdary S, Sepehr A, Bolourchi N, Barzi SM, Haririzadeh Jouriani F, Riazi-Rad F, Shahcheraghi F, Badmasti F. Immunization with recombinant DcaP-like protein and AbOmpA revealed protections against sepsis infection of multi-drug resistant Acinetobacter baumannii ST2 Pas in a C57BL/6 mouse model. Microb Pathog 2023; 174:105882. [PMID: 36403713 DOI: 10.1016/j.micpath.2022.105882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/11/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUNDS The prevalence of infections associated with multi-drug resistant (MDR) Acinetobacter baumannii is increasing worldwide. Therefore, the introduction of effective vaccines against this bacterium seems necessary. METHODS AbOmpA and DcaP-like protein were selected as promising and putative immunogenic candidates based on previous in silico studies. Three formulations including AbOmpA, DcaP-like protein, and AbOmpA + DcaP-like protein were injected into C57BL/6 mice three times with Alum adjuvant. The specific production of IgG antibodies (e.g. total IgG, IgG1 and IgG2c) and cytokines (e.g. IL-4, IL-6, and IL-17A), were evaluated. LD50% of MDR A. baumannii ST2Pas was measured using Probit's method. After the challenge with bacteria, a decrease in bacterial loads (DLs) in the lung and spleen of mice was measured. Then serum bactericidal assay was performed to determine the function of antibodies on day 42. In addition, histopathological examinations of the spleen and lung, the number of macrophage and neutrophil, as well as the rate of lymphocyte infiltration were assessed. RESULTS The highest level of total IgG was reported in the group immunized with DcaP-like protein on day 42. The survival rate of mice was 80% in the AbOmpA immunized group and 100% for the rest of two groups. DLs in the spleen of mice immunized with AbOmpA, DcaP-like protein, and combination form were 3.5, 3, and 3.4 Log10 (CFU/g), respectively. While in the lung, the DLs were 7.5 Log10 (CFU/g) for the AbOmpA group and 5 for the rest of two groups. The levels of IL-6, IL-4, and IL-17A were significantly decreased in all immunized groups after the bacterial challenge (except for IL-17A in the group of AbOmpA). The bactericidal effect of antibodies against DcaP-like protein was more effective. No histopathological damage was observed in the combination immunized group. The DcaP-like protein was more effective in neutrophil and macrophage deployment and decreased lymphocyte infiltration. CONCLUSION The results of immunization with AbOmpA + DcaP-like protein induced a protective reaction against the sepsis infection of MDR A. baumannii. It seems that in the future, these proteins can be considered as promising components in the development of the A. baumannii vaccine.
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Affiliation(s)
| | - Soheila Ajdary
- Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
| | - Amin Sepehr
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Negin Bolourchi
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | | | | | - Farhad Riazi-Rad
- Department of Immunology, Pasteur Institute of Iran, Tehran, Iran
| | | | - Farzad Badmasti
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran.
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Buchhorn de Freitas S, Hartwig DD. Promising targets for immunotherapeutic approaches against Acinetobacter baumannii. Microb Pathog 2022; 173:105855. [DOI: 10.1016/j.micpath.2022.105855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022]
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Jeffreys S, Chambers JP, Yu JJ, Hung CY, Forsthuber T, Arulanandam BP. Insights into Acinetobacter baumannii protective immunity. Front Immunol 2022; 13:1070424. [PMID: 36466845 PMCID: PMC9716351 DOI: 10.3389/fimmu.2022.1070424] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/07/2022] [Indexed: 11/19/2022] Open
Abstract
Acinetobacter baumannii is a nosocomic opportunistic Gram-negative bacteria known for its extensive drug-resistant phenotype. A. baumannii hospital-acquired infections are major contributors to increased costs and mortality observed during the COVID-19 pandemic. With few effective antimicrobials available for treatment of this pathogen, immune-based therapy becomes an attractive strategy to combat multi-drug resistant Acinetobacter infection. Immunotherapeutics is a field of growing interest with advances in vaccines and monoclonal antibodies providing insight into the protective immune response required to successfully combat this pathogen. This review focuses on current knowledge describing the adaptive immune response to A. baumannii, the importance of antibody-mediated protection, developments in cell-mediated protection, and their respective therapeutic application going forward. With A. baumannii’s increasing resistance to most current antimicrobials, elucidating an effective host adaptive immune response is paramount in the guidance of future immunotherapeutic development.
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Affiliation(s)
- Sean Jeffreys
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
| | - James P. Chambers
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Jieh-Juen Yu
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Chiung-Yu Hung
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Thomas Forsthuber
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Bernard P. Arulanandam
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
- Department of Immunology, Tufts University School of Medicine, Boston, MA, United States
- *Correspondence: Bernard P. Arulanandam,
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Mesbahi Moghaddam M, Rasooli I, Ghaini MH, Jahangiri A, Ramezanalizadeh F, Ghasemkhah Tootkleh R. Immunoprotective characterization of egg yolk immunoglobulin raised to loop 3 of outer membrane protein 34 (Omp34) in a murine model against Acinetobacter baumannii. Mol Immunol 2022; 149:87-93. [DOI: 10.1016/j.molimm.2022.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 06/02/2022] [Accepted: 06/23/2022] [Indexed: 10/17/2022]
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Rahbar MR, Mubarak SMH, Hessami A, Khalesi B, Pourzardosht N, Khalili S, Zanoos KA, Jahangiri A. A unique antigen against SARS-CoV-2, Acinetobacter baumannii, and Pseudomonas aeruginosa. Sci Rep 2022; 12:10852. [PMID: 35760825 PMCID: PMC9237110 DOI: 10.1038/s41598-022-14877-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/14/2022] [Indexed: 02/07/2023] Open
Abstract
The recent outbreak of COVID-19 has increased hospital admissions, which could elevate the risk of nosocomial infections, such as A. baumannii and P. aeruginosa infections. Although effective vaccines have been developed against SARS-CoV-2, no approved treatment option is still available against antimicrobial-resistant strains of A. baumannii and P. aeruginosa. In the current study, an all-in-one antigen was designed based on an innovative, state-of-the-art strategy. In this regard, experimentally validated linear epitopes of spike protein (SARS-CoV-2), OmpA (A. baumannii), and OprF (P. aeruginosa) were selected to be harbored by mature OmpA as a scaffold. The selected epitopes were used to replace the loops and turns of the barrel domain in OmpA; OprF311–341 replaced the most similar sequence within the OmpA, and three validated epitopes of OmpA were retained intact. The obtained antigen encompasses five antigenic peptides of spike protein, which are involved in SARS-CoV-2 pathogenicity. One of these epitopes, viz. QTQTNSPRRARSV could trigger antibodies preventing super-antigenic characteristics of spike and alleviating probable autoimmune responses. The designed antigen could raise antibodies neutralizing emerging variants of SARS-CoV-2 since at least two epitopes are consensus. In conclusion, the designed antigen is expected to raise protective antibodies against SARS-CoV-2, A. baumannii, and P. aeruginosa.
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Affiliation(s)
- Mohammad Reza Rahbar
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Shaden M H Mubarak
- Department of Clinical Laboratory Science, Faculty of Pharmacy, University of Kufa, Najaf, Iraq
| | - Anahita Hessami
- School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Bahman Khalesi
- Department of Research and Production of Poultry Viral Vaccine, Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran
| | - Navid Pourzardosht
- Biochemistry Department, Guilan University of Medical Sciences, Rasht, Iran
| | - Saeed Khalili
- Department of Biology Sciences, Shahid Rajaee Teacher Training University, Tehran, Iran
| | - Kobra Ahmadi Zanoos
- Young Researchers Club, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Abolfazl Jahangiri
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Vanak Sq. Molasadra St., P.O. Box 1435915371, Tehran, Iran.
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Alipouri S, Rasooli I, Ghaini MH, Jahangiri A, Darvish Alipour Astaneh S, Ramezanalizadeh F. Immunity induced by valine-glycine repeat protein G imparts histoprotection of vital body organs against Acinetobacter baumannii. J Genet Eng Biotechnol 2022; 20:42. [PMID: 35254548 PMCID: PMC8901899 DOI: 10.1186/s43141-022-00325-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 02/26/2022] [Indexed: 11/10/2022]
Abstract
Background Efforts toward the development of an effective vaccine against Acinetobacter baumannii, one of the most notorious nosocomial pathogens, are still ongoing. In this regard, virulence factors are interesting targets. Type VI secretion system (T6SS) participates in the pathogenicity of A. baumannii. VgrG is a crucial component of T6SS prevalent among A. baumannii strains. This study was conducted to evaluate the immunoprotectivity of recombinant VgrG (rVgrG) cloned and over-expressed in Escherichia coli BL21 (DE3). BALB/c mice were immunized with the purified rVgrG. Specific anti-VgrG IgG titers were assessed by ELISA. Actively and passively immunized mice were challenged with lethal doses of A. baumannii ATCC 19606. The survival rate, the bacterial burden, and histopathology of tissues in infected mice were examined. Results Anti-VgrG IgG (p < 0.0001) was significantly increased in immunized mice. No death was seen in actively immunized mice infected with the lethal dose (LD) of 1.9 × 108 CFU of A. baumannii ATCC 19606 within 72 h. Challenge with 2.4 × 108 CFU of the pathogen showed a 75% survival rate. All immunized mice infected with 3.2 × 108 CFU of the pathogen died within 12 h. In passive immunization, no death was observed in mice that received LD of the bacteria incubated with the 1:250 dilution of the immune sera. An increased number of neutrophils around the peribronchial and perivascular areas were seen in unimmunized mouse lungs while passively immunized mice revealed moderate inflammation with infiltration of mixed mononuclear cells and neutrophils. The livers of the unimmunized mice showed inflammation and necrosis in contrast to the livers from immunized mice. Hyperplasia of the white pulp and higher neutrophils were evident in the spleen of unimmunized mice as against the normal histology of the immunized group. Conclusions VgrG is a protective antigen that could be topologically accessible to the host antibodies. Although VgrG is not sufficient to be assigned as a stand-alone antigen for conferring full protection, it could participate in multivalent vaccine developments for elevated efficacy. Supplementary Information The online version contains supplementary material available at 10.1186/s43141-022-00325-4.
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Affiliation(s)
- Saeed Alipouri
- Department of Biology, Shahed University, Qom Expressway, Tehran, 3319118651, Iran
| | - Iraj Rasooli
- Department of Biology, Shahed University, Qom Expressway, Tehran, 3319118651, Iran. .,Molecular Microbiology Research Center and Department of Biology, Shahed University, Tehran, Iran.
| | - Mohammad Hossein Ghaini
- Department of Anatomical Sciences and Pathology, School of Medicine, Shahed University, Tehran, Iran
| | - Abolfazl Jahangiri
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Shakiba Darvish Alipour Astaneh
- Department of Biotechnology, Semnan University, Central Administration of Semnan University, Campus 1, Semnan, I. R. of Iran Semnan, P.O. Box 35131-19111, Semnan, Iran
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Singh R, Capalash N, Sharma P. Vaccine development to control the rising scourge of antibiotic-resistant Acinetobacter baumannii: a systematic review. 3 Biotech 2022; 12:85. [PMID: 35261870 PMCID: PMC8890014 DOI: 10.1007/s13205-022-03148-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 02/11/2022] [Indexed: 03/02/2023] Open
Abstract
Acinetobacter baumannii has emerged as one of major nosocomial pathogen and global emergence of multidrug-resistant strains has become a challenge for developing effective treatment options. A. baumannii has developed resistance to almost all the antibiotics viz. beta-lactams, carbapenems, tigecycline and now colistin, a last resort of antibiotics. The world is on the cusp of post antibiotic era and the evolution of multi-, extreme- and pan–drug-resistant A. baumannii strains is its obvious harbinger. Various combinations of antibiotics have been investigated but no successful treatment option is available. All these failed efforts have led researchers to develop and implement prophylactic vaccination for the prevention of infections caused by this pathogen. In this review, the advantages and disadvantages of active and passive immunization, the types of sub-unit and multi-component vaccine candidates investigated against A. baumannii viz. whole cell organism, outer membrane vesicles, outer membrane complexes, conjugate vaccines and sub-unit vaccines have been discussed. In addition, the benefits of Reverse vaccinology are emphasized here in which the potential vaccine candidates are predicted using bioinformatic online tools prior to in vivo validations.
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Khalid K, Irum S, Ullah SR, Andleeb S. In-Silico Vaccine Design Based on a Novel Vaccine Candidate Against Infections Caused by Acinetobacter baumannii. Int J Pept Res Ther 2021; 28:16. [PMID: 34873398 PMCID: PMC8636788 DOI: 10.1007/s10989-021-10316-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2021] [Indexed: 12/24/2022]
Abstract
Acinetobacter baumannii is notorious for causing serious infections of the skin, lungs, soft tissues, bloodstream, and urinary tract. Despite the overwhelming information available so far, there has still been no approved vaccine in the market to prevent these infections. Therefore, this study focuses on developing a rational vaccine design using the technique of epitope mapping to curb the infections caused by A. baumannii. An outer membrane protein with immunogenic potential as well as all the properties of a good vaccine candidate was selected and used to calculate epitopes for selection on the basis of a low percentile rank, high binding scores, good immunological properties, and non-allergenicity. Thus, a 240 amino-acid vaccine sequence was obtained by manually joining all the epitopes in sequence-wise manner with the appropriate linkers, namely AAY, GPGPG, and EAAAK. Additionally, a 50S ribosomal protein L7/L12, agonist to the human innate immune receptors was attached to the N-terminus to increase the overall immune response towards the vaccine. As a result, enhanced overall protein stability, expression, immunostimulatory capabilities, and solubility of the designed construct were observed. Molecular dynamic simulations revealed the compactness and stability of the polypeptide construct. Moreover, molecular docking exhibited strong binding of the designed vaccine with TLR-4 and TLR-9. In-silico immune simulations indicated an immense increment in T-cell and B-cell populations. Bioinformatic tools also significantly assisted with optimizing codons which allowed for successful cloning of constructs into desired host vectors. Using in-silico tools to design a vaccine against A. baumannii demonstrated that this construct could pave the way for successfully combating infections caused by multidrug-resistant bacteria.
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Affiliation(s)
- Kashaf Khalid
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000 Pakistan
| | - Sidra Irum
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000 Pakistan
| | - Sidra Rahmat Ullah
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000 Pakistan
| | - Saadia Andleeb
- Department of Industrial Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, 44000 Pakistan
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Application of Reverse Vaccinology and Immunoinformatic Strategies for the Identification of Vaccine Candidates Against Shigella flexneri. Methods Mol Biol 2021. [PMID: 34784029 DOI: 10.1007/978-1-0716-1900-1_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Reverse vaccinology (RV) was first introduced by Rappuoli for the development of an effective vaccine against serogroup B Neisseria meningitidis (MenB). With the advances in next generation sequencing technologies, the amount of genomic data has risen exponentially. Since then, the RV approach has widely been used to discover potential vaccine protein targets by screening whole genome sequences of pathogens using a combination of sophisticated computational algorithms and bioinformatic tools. In contrast to conventional vaccine development strategies, RV offers a novel method to facilitate rapid vaccine design and reduces reliance on the traditional, relatively tedious, and labor-intensive approach based on Pasteur"s principles of isolating, inactivating, and injecting the causative agent of an infectious disease. Advances in biocomputational techniques have remarkably increased the significance for the rapid identification of the proteins that are secreted or expressed on the surface of pathogens. Immunogenic proteins which are able to induce the immune response in the hosts can be predicted based on the immune epitopes present within the protein sequence. To date, RV has successfully been applied to develop vaccines against a variety of infectious pathogens. In this chapter, we apply a pipeline of bioinformatic programs for identification of Shigella flexneri potential vaccine candidates as an illustration immunoinformatic tools available for RV.
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15
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In Silico Screening of Putative Corynebacterium pseudotuberculosis Antigens and Serological Diagnosis for Caseous Lymphadenitis in Sheep by Enzyme-Linked Immunosorbent Assay. Vet Med Int 2021; 2021:9931731. [PMID: 34373777 PMCID: PMC8349269 DOI: 10.1155/2021/9931731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/17/2021] [Indexed: 11/18/2022] Open
Abstract
Corynebacterium pseudotuberculosis is the etiologic agent of Caseous Lymphadenitis (CLA), a disease leading to severe damage in sheep and goats farming due to the lack of serological diagnosis, treatment, and effective prophylaxis. In this context, several strategies in an attempt to discover new antigens to compose diagnosis assays or vaccines are fundamental. Therefore, this study aimed to use bioinformatics software to evaluate the critical chemical characteristics of unknown proteins of C. pseudotuberculosis by selecting them for heterologous expression in Escherichia coli. For this purpose, six protein sequences of ascorbate transporter subunit, UPF protein, MMPL family transporter, Ribonuclease, Iron ABC transporter domain-containing permease, and fimbrial subunit were obtained. In silico analyses were performed using amino acid sequences to access immunodominant epitopes and their antigenic and allergenic potential and physicochemical characterization. The expressed proteins were used as an antigen for serological diagnosis by ELISA. All proteins showed distinct immunodominant epitopes and potential antigenic characteristics. The only proteins expressed were PTS and Ribonuclease. In parallel, we expressed CP40 and all were used with ELISA antigen in 49 CLA positive sera and 26 CLA negative sera. The proteins alone showed 100% sensitivity and 96.2%, 92.3%, and 88.5% specificity for rPTS, rRibonuclease, and rCP40, respectively. When proteins were combined, they showed 100% sensitivity and 84.6%, 92.3%, 88.5%, and 92.3% specificity for rPTS/rCp40, rRibonuclease/rCP40, rPTS/rRibonuclease, and rPTS/rRibonuclease/rCP40, respectively. The results of this study show an excellent correlation of sensitivity and specificity with all proteins. None of the specificity values preclude the potential of rPTS, rRibonuclease, or rCP40 for use in ELISA diagnostic assays since the results of this work are superior to those of other studies on CLA diagnosis described in the literature.
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Kamuyu G, Suen Cheng Y, Willcocks S, Kewcharoenwong C, Kiratisin P, Taylor PW, Wren BW, Lertmemongkolchai G, Stabler RA, Brown J. Sequential Vaccination With Heterologous Acinetobacter baumannii Strains Induces Broadly Reactive Antibody Responses. Front Immunol 2021; 12:705533. [PMID: 34394105 PMCID: PMC8363311 DOI: 10.3389/fimmu.2021.705533] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/08/2021] [Indexed: 12/11/2022] Open
Abstract
Antibody therapy may be an alternative treatment option for infections caused by the multi-drug resistant (MDR) bacterium Acinetobacter baumannii. As A. baumannii has multiple capsular serotypes, a universal antibody therapy would need to target conserved protein antigens rather than the capsular polysaccharides. We have immunized mice with single or multiple A. baumannii strains to induce antibody responses to protein antigens, and then assessed whether these responses provide cross-protection against a collection of genetically diverse clinical A. baumannii isolates. Immunized mice developed antibody responses to multiple protein antigens. Flow cytometry IgG binding assays and immunoblots demonstrated improved recognition of both homologous and heterologous clinical strains in sera from mice immunized with multiple strains compared to a single strain. The capsule partially inhibited bacterial recognition by IgG and the promotion of phagocytosis by human neutrophils. However, after immunization with multiple strains, serum antibodies to protein antigens promoted neutrophil phagocytosis of heterologous A. baumannii strains. In an infection model, mice immunized with multiple strains had lower bacterial counts in the spleen and liver following challenge with a heterologous strain. These data demonstrate that antibodies targeting protein antigens can improve immune recognition and protection against diverse A. baumannii strains, providing support for their use as an antibody therapy.
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Affiliation(s)
- Gathoni Kamuyu
- Centre for Inflammation and Tissue Repair, University College London (UCL) Respiratory, London, United Kingdom
| | - Yat Suen Cheng
- Centre for Inflammation and Tissue Repair, University College London (UCL) Respiratory, London, United Kingdom
| | - Sam Willcocks
- London School of Hygiene and Tropical Medicine, Infectious and Tropical Disease, Department of Infection Biology, London, United Kingdom
| | - Chidchamai Kewcharoenwong
- Cellular and Molecular Immunology Unit, Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Pattarachai Kiratisin
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok-Noi, Bangkok, Thailand
| | - Peter W Taylor
- School of Pharmacy, University College London, London, United Kingdom
| | - Brendan W Wren
- London School of Hygiene and Tropical Medicine, Infectious and Tropical Disease, Department of Infection Biology, London, United Kingdom
| | - Ganjana Lertmemongkolchai
- Cellular and Molecular Immunology Unit, Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.,Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Richard A Stabler
- London School of Hygiene and Tropical Medicine, Infectious and Tropical Disease, Department of Infection Biology, London, United Kingdom
| | - Jeremy Brown
- Centre for Inflammation and Tissue Repair, University College London (UCL) Respiratory, London, United Kingdom
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17
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de Freitas SB, Wozeak DR, Neto AS, Cardoso TL, Hartwig DD. A hypothetical adhesin protein induces anti-biofilm antibodies against multi-drug resistant Acinetobacter baumannii. Microb Pathog 2021; 159:105112. [PMID: 34314810 DOI: 10.1016/j.micpath.2021.105112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 06/13/2021] [Accepted: 07/22/2021] [Indexed: 10/20/2022]
Abstract
The increase in multidrug-resistant (MDR) Acinetobacter baumannii strains in hospital environments has generated great concern around the world. Biofilm is one of the forms of bacterial adaptation that is increasingly leading to antimicrobial resistance and therapeutic failure. The search for alternative therapeutic strategies, especially non-antibiotic-based, is urgently needed. In this study, we produce polyclonal antibodies (pAbs) in murine models against recombinant CAM87009.1 antigen, an A. baumannii fimbriae protein. The pAbs produced were isotyped and anti-biofilm activity evaluated in the A. baumannii ATCC® 19606 standard strain and nine MDR clinical isolates. All clinical isolates were analyzed for the presence of the cam87009.1 gene using the PCR technique, and one of the isolates did not have the gene in its genome. After four intraperitoneal immunizations (days 0, 14, 21, and 28) of mice with rCAM87009.1 and Freund's adjuvant, a significant antibody titer was detected by indirect enzyme-linked immunosorbent assay (ELISA) since the first immunization (1:6400), and the level increased until the 4th immunization (1:819,200). IgM, IgA, IgG1, IgG2a, IgG2b, and IgG3 isotypes were identified in the serum of immunized mice (P < 0.001). The anti-rCAM87009.1 pAb was able to inhibit biofilm formation in 80 % of the strains evaluated in this study, including the ATCC® 19606 strain. The rCAM87009.1 proves to be a promising target in the development of alternative strategies to control biofilm-forming in A. baumannii MDR strains.
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Affiliation(s)
- Stella Buchhorn de Freitas
- Center of Technological Development, Biotechnology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil; Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Daniela Rodriguero Wozeak
- Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Amilton Seixas Neto
- Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Thayná Laner Cardoso
- Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, Pelotas, RS, Brazil
| | - Daiane Drawanz Hartwig
- Center of Technological Development, Biotechnology, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil; Department of Microbiology and Parasitology, Biology Institute, Federal University of Pelotas, Pelotas, RS, Brazil.
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18
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Badmasti F, Habibi M, Firoozeh F, Fereshteh S, Bolourchi N, Goodarzi NN. The combination of CipA and PBP-7/8 proteins contribute to the survival of C57BL/6 mice from sepsis of Acinetobacter baumannii. Microb Pathog 2021; 158:105063. [PMID: 34166729 DOI: 10.1016/j.micpath.2021.105063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/13/2021] [Accepted: 06/16/2021] [Indexed: 10/21/2022]
Abstract
Due to the emergence of multi-drug resistant Acinetobacter baumannii strains, there is an urgent need to develop several new strategies to control this bacterium. In this context, vaccination may be the best approach to reduce the morbidity and mortality associated with MDR isolates in vulnerable groups. Serum resistance factors have a key role in the pathogenesis of A. baumannii and can be considered as potential vaccine candidates. This project aimed to evaluate the immunological reactivity of CipA and PBP-7/8 as two serum resistance factors in a combination form against sepsis infections of A. baumannii. Recombinant proteins were obtained and immunological evaluations were performed against sepsis infection in the C57BL/6 mouse model. The data showed a statistically significant increase in total IgG levels in all three immunization regimens (CipA, PBP-7/8, and CipA + PBP-7/8) compared to the control group. The ratios of IgG2c/IgG1 in the CipA, PBP-7/8, and CipA + PBP-7/8 schedules were 8.7, 46.50, and 33.29, respectively. It appears that the immunization schedules developed a strong polarized Th1 response. The cytokine profiles of the three plans showed that IFN-γ was highly concentrated in the combination plan. However, the highest concentration of IL-17 belonged to the PBP-7/8 plan. In conclusion, the data of total IgG, survival rates and splenic bacterial loads showed that the CipA + PBP-7/8 plan was more effective than each protein individually.
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Affiliation(s)
- Farzad Badmasti
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran; Microbiology Research Center (MRC), Pasteur Institute of Iran, Iran.
| | - Mehri Habibi
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
| | - Farzaneh Firoozeh
- Department of Microbiology, School of Medicine, Alborz University of Medical Science, Karaj, Iran
| | | | - Negin Bolourchi
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Narjes Noori Goodarzi
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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19
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López-Siles M, Corral-Lugo A, McConnell MJ. Vaccines for multidrug resistant Gram negative bacteria: lessons from the past for guiding future success. FEMS Microbiol Rev 2021; 45:fuaa054. [PMID: 33289833 DOI: 10.1093/femsre/fuaa054] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/18/2020] [Indexed: 02/07/2023] Open
Abstract
Antimicrobial resistance is a major threat to global public health. Vaccination is an effective approach for preventing bacterial infections, however it has not been successfully applied to infections caused by some of the most problematic multidrug resistant pathogens. In this review, the potential for vaccines to contribute to reducing the burden of disease of infections caused by multidrug resistant Gram negative bacteria is presented. Technical, logistical and societal hurdles that have limited successful vaccine development for these infections in the past are identified, and recent advances that can contribute to overcoming these challenges are assessed. A synthesis of vaccine technologies that have been employed in the development of vaccines for key multidrug resistant Gram negative bacteria is included, and emerging technologies that may contribute to future successes are discussed. Finally, a comprehensive review of vaccine development efforts over the last 40 years for three of the most worrisome multidrug resistant Gram negative pathogens, Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa is presented, with a focus on recent and ongoing studies. Finally, future directions for the vaccine development field are highlighted.
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Affiliation(s)
- Mireia López-Siles
- Intrahospital Infections Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Andrés Corral-Lugo
- Intrahospital Infections Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Michael J McConnell
- Intrahospital Infections Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Madrid, Spain
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20
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McConnell MJ, Martín-Galiano AJ. Designing Multi-Antigen Vaccines Against Acinetobacter baumannii Using Systemic Approaches. Front Immunol 2021; 12:666742. [PMID: 33936107 PMCID: PMC8085427 DOI: 10.3389/fimmu.2021.666742] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 03/26/2021] [Indexed: 12/12/2022] Open
Abstract
Vaccines and monoclonal antibodies are promising approaches for preventing and treating infections caused by multidrug resistant Acinetobacter baumannii. However, only partial protection has been achieved with many previously tested protein antigens, which suggests that vaccines incorporating multiple antigens may be necessary in order to obtain high levels of protection. Several aspects that use the wealth of omic data available for A. baumannii have not been fully exploited for antigen identification. In this study, the use of fractionated proteomic and computational data from ~4,200 genomes increased the number of proteins potentially accessible to the humoral response to 8,824 non-redundant proteins in the A. baumannii panproteome. Among them, 59% carried predicted B-cell epitopes and T-cell epitopes recognized by two or more alleles of the HLA class II DP supertype. Potential cross-reactivity with human proteins was detected for 8.9% of antigens at the protein level and 2.7% at the B-cell epitope level. Individual antigens were associated with different infection types by genomic, transcriptomic or functional analyses. High intra-clonal genome density permitted the identification of international clone II as a “vaccitype”, in which 20% of identified antigens were specific to this clone. Network-based centrality measurements were used to identify multiple immunologic nodes. Data were formatted, unified and stored in a data warehouse database, which was subsequently used to identify synergistic antigen combinations for different vaccination strategies. This study supports the idea that integration of multi-omic data and fundamental knowledge of the pathobiology of drug-resistant bacteria can facilitate the development of effective multi-antigen vaccines against these challenging infections.
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Affiliation(s)
- Michael J McConnell
- Intrahospital Infections Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Spain
| | - Antonio J Martín-Galiano
- Intrahospital Infections Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Spain
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21
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Ma C, Chen W. Where are we and how far is there to go in the development of an Acinetobacter vaccine? Expert Rev Vaccines 2021; 20:281-295. [PMID: 33554671 DOI: 10.1080/14760584.2021.1887735] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Healthcare-associated infections caused by multidrug-resistant Acinetobacter baumannii are becoming alarming worldwide. However, the pipeline of new antibiotics is very limited. Vaccination is one of the most cost effective and promising strategies to prevent infections and can play an important role in combat multidrug resistance A. baumannii and prevent the development of new drug resistance. AREA COVERED This review gives an overview of the research and development of A. baumannii vaccines during the past five years (2015-2020), discusses the key progresses and current challenges of the field, and speculates on the future of A. baumannii vaccine development. EXPERT OPINION Moderate progresses have been made in the research and development of A. baumannii vaccine in the last five years, in particular in the areas of identification of new protein targets, development of multicomponent vaccines, and use of vaccines and antibodies as adjuncts for antibiotics therapies. However, substantial scientific and logistic challenges, such as selection of lead vaccine candidates and formulation, vaccine clinical trials and targeted population, and financial incentives, remain. Thus, innovative strategies will be needed before an A. baumannii vaccine candidate can be brought into late stage of preclinical development in next five years.
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Affiliation(s)
- Crystal Ma
- Human Health Therapeutics Research Center (HHT), National Research Council Canada, Ottawa, Ontario Canada
| | - Wangxue Chen
- Human Health Therapeutics Research Center (HHT), National Research Council Canada, Ottawa, Ontario Canada.,Department of Biology, Brock University, St. Catharines, Ontario Canada
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22
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Recent Advances in the Pursuit of an Effective Acinetobacter baumannii Vaccine. Pathogens 2020; 9:pathogens9121066. [PMID: 33352688 PMCID: PMC7766458 DOI: 10.3390/pathogens9121066] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 12/22/2022] Open
Abstract
Acinetobacter baumannii has been a major cause of nosocomial infections for decades. The absence of an available vaccine coupled with emerging multidrug resistance has prevented the medical community from effectively controlling this human pathogen. Furthermore, the ongoing pandemic caused by SARS-CoV-2 has increased the risk of hospitalized patients developing ventilator-associated pneumonia caused by bacterial opportunists including A. baumannii. The shortage of antibiotics in the development pipeline prompted the World Health Organization to designate A. baumannii a top priority for the development of new medical countermeasures, such as a vaccine. There are a number of important considerations associated with the development of an A. baumannii vaccine, including strain characteristics, diverse disease manifestations, and target population. In the past decade, research efforts have revealed a number of promising new immunization strategies that could culminate in a safe and protective vaccine against A. baumannii. In this review, we highlight the recent progress in the development of A. baumannii vaccines, discuss potential challenges, and propose future directions to achieve an effective intervention against this human pathogen.
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Jahangiri A, Neshani A, Mirhosseini SA, Ghazvini K, Zare H, Sedighian H. Synergistic effect of two antimicrobial peptides, Nisin and P10 with conventional antibiotics against extensively drug-resistant Acinetobacter baumannii and colistin-resistant Pseudomonas aeruginosa isolates. Microb Pathog 2020; 150:104700. [PMID: 33346078 DOI: 10.1016/j.micpath.2020.104700] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 11/17/2020] [Accepted: 12/05/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Infections caused by drug-resistant strains of Acinetobacter baumannii and Pseudomonas aeruginosa are now a global problem that requires the immediate development of new antimicrobial drugs. Combination therapy and using antimicrobial peptides are two strategies with high potential to solve this issue. By these strategies, this study aimed to determine the antimicrobial effect of Nisin and P10 antimicrobial peptides on extensively drug-resistant Acinetobacter baumannii and colistin-resistant Pseudomonas aeruginosa isolates, and investigate the most effective combination of an antimicrobial peptide with an antibiotic. MATERIAL AND METHODS This study was performed on five resistant clinical isolates and one standard strain for each kind of bacterium. First, the minimum inhibitory concentrations of two antimicrobial peptides (Nisin and P10) and five common antibiotics for the treatment of Gram-negative bacteria (ceftazidime, tobramycin, ciprofloxacin, doripenem, and colistin) was determined using Scanner-Assisted Colorimetric MIC Method. Then, the combination effect of P10+Nisin, P10+antibiotics, Nisin + antibiotics was investigated using checkerboard method. RESULTS The MIC value of Nisin and P10 against studied pathogens were 64-256 and 8-32 μg/ml, respectively. P10+Nisin combination showed synergistic effect against standard strains and additive effect against drug-resistant clinical isolates. It was also found that the combination effect of P10+ceftazidim, P10+doripenem, and Nisin + colistin was synergistic in most cases. Nisin + tobramycin combination showed synergistic effect in exposure to standard strains, while the synergy is strain-dependent against drug-resistant clinical isolates. CONCLUSION In conclusion, the synergism of Nisin + colistin and P10+ceftazidime/doripenem could be of great therapeutic value as antimicrobial drugs against infections caused by colistin-resistant P.aeruginosa and XDR A. baumannii.
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Affiliation(s)
- Abolfazl Jahangiri
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Alireza Neshani
- Department of Laboratory Sciences, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran; Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Seyed Ali Mirhosseini
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Kiarash Ghazvini
- Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hosna Zare
- Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hamid Sedighian
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran.
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24
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Bakare OO, Keyster M, Pretorius A. Identification of biomarkers for the accurate and sensitive diagnosis of three bacterial pneumonia pathogens using in silico approaches. BMC Mol Cell Biol 2020; 21:82. [PMID: 33218302 PMCID: PMC7678116 DOI: 10.1186/s12860-020-00328-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/09/2020] [Indexed: 11/10/2022] Open
Abstract
Background Pneumonia ranks as one of the main infectious sources of mortality among kids under 5 years of age, killing 2500 a day; late research has additionally demonstrated that mortality is higher in the elderly. A few biomarkers, which up to this point have been distinguished for its determination lack specificity, as these biomarkers fail to build up a differentiation between pneumonia and other related diseases, for example, pulmonary tuberculosis and Human Immunodeficiency Infection (HIV). There is an inclusive global consensus of an improved comprehension of the utilization of new biomarkers, which are delivered in light of pneumonia infection for precision identification to defeat these previously mentioned constraints. Antimicrobial peptides (AMPs) have been demonstrated to be promising remedial specialists against numerous illnesses. This research work sought to identify AMPs as biomarkers for three bacterial pneumonia pathogens such as Streptococcus pneumoniae, Klebsiella pneumoniae, Acinetobacter baumannii using in silico technology. Hidden Markov Models (HMMER) was used to identify putative anti-bacterial pneumonia AMPs against the identified receptor proteins of Streptococcus pneumoniae, Klebsiella pneumoniae, and Acinetobacter baumannii. The physicochemical parameters of these putative AMPs were computed and their 3-D structures were predicted using I-TASSER. These AMPs were subsequently subjected to docking interaction analysis against the identified bacterial pneumonia pathogen proteins using PATCHDOCK. Results The in silico results showed 18 antibacterial AMPs which were ranked based on their E values with significant physicochemical parameters in conformity with known experimentally validated AMPs. The AMPs also bound the pneumonia receptors of their respective pathogens sensitively at the extracellular regions. Conclusions The propensity of these AMPs to bind pneumonia pathogens proteins justifies that they would be potential applicant biomarkers for the recognizable detection of these bacterial pathogens in a point-of-care POC pneumonia diagnostics. The high sensitivity, accuracy, and specificity of the AMPs likewise justify the utilization of HMMER in the design and discovery of AMPs for disease diagnostics and therapeutics.
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Affiliation(s)
- Olalekan Olanrewaju Bakare
- Bioinformatics Research Group, Biotechnology Department, University of the Western Cape, Cape Town, 7535, South Africa. .,Environmental Biotechnology Laboratory, Biotechnology Department, University of the Western Cape, Cape Town, 7535, South Africa.
| | - Marshall Keyster
- Environmental Biotechnology Laboratory, Biotechnology Department, University of the Western Cape, Cape Town, 7535, South Africa
| | - Ashley Pretorius
- Bioinformatics Research Group, Biotechnology Department, University of the Western Cape, Cape Town, 7535, South Africa
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Uppalapati SR, Sett A, Pathania R. The Outer Membrane Proteins OmpA, CarO, and OprD of Acinetobacter baumannii Confer a Two-Pronged Defense in Facilitating Its Success as a Potent Human Pathogen. Front Microbiol 2020; 11:589234. [PMID: 33123117 PMCID: PMC7573547 DOI: 10.3389/fmicb.2020.589234] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/11/2020] [Indexed: 12/12/2022] Open
Abstract
Of all the ESKAPE pathogens, carbapenem-resistant and multidrug-resistant Acinetobacter baumannii is the leading cause of hospital-acquired and ventilator-associated pneumonia. A. baumannii infections are notoriously hard to eradicate due to its propensity to rapidly acquire multitude of resistance determinants and the virulence factor cornucopia elucidated by the bacterium that help it fend off a wide range of adverse conditions imposed upon by host and environment. One such weapon in the arsenal of A. baumannii is the outer membrane protein (OMP) compendium. OMPs in A. baumannii play distinctive roles in facilitating the bacterial acclimatization to antibiotic- and host-induced stresses, albeit following entirely different mechanisms. OMPs are major immunogenic proteins in bacteria conferring bacteria host-fitness advantages including immune evasion, stress tolerance, and resistance to antibiotics and antibacterials. In this review, we summarize the current knowledge of major A. baumannii OMPs and discuss their versatile role in antibiotic resistance and virulence. Specifically, we explore how OmpA, CarO, and OprD-like porins mediate antibiotic and amino acid shuttle and host virulence.
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Affiliation(s)
- Siva R Uppalapati
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, India
| | - Abhiroop Sett
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, India
| | - Ranjana Pathania
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, India
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26
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Chen W. Host Innate Immune Responses to Acinetobacter baumannii Infection. Front Cell Infect Microbiol 2020; 10:486. [PMID: 33042864 PMCID: PMC7521131 DOI: 10.3389/fcimb.2020.00486] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 08/05/2020] [Indexed: 12/23/2022] Open
Abstract
Acinetobacter baumannii has emerged as a major threat to global public health and is one of the key human pathogens in healthcare (nosocomial and community-acquired)-associated infections. Moreover, A. baumannii rapidly develops resistance to multiple antibiotics and is now globally regarded as a serious multidrug resistant pathogen. There is an urgent need to develop novel vaccines and immunotherapeutics as alternatives to antibiotics for clinical management of A. baumannii infection. However, our knowledge of host immune responses to A. baumannii infection and the identification of novel therapeutic targets are significantly lacking. This review highlights the recent advances and critical gaps in our understanding how A. baumannii interacts with the host innate pattern-recognition receptors, induces a cascade of inflammatory cytokine and chemokine responses, and recruits innate immune effectors (such as neutrophils and macrophages) to the site of infection for effective control of the infection. Such knowledge will facilitate the identification of new targets for the design and development of effective therapeutics and vaccines to fight this emerging threat.
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Affiliation(s)
- Wangxue Chen
- Human Health and Therapeutics (HHT) Research Center, National Research Council Canada, Ottawa, ON, Canada.,Department of Biology, Brock University, St. Catharines, ON, Canada
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27
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Wang R, Zhao P, Ge X, Tian P. Overview of Alternaria alternata Membrane Proteins. Indian J Microbiol 2020; 60:269-282. [PMID: 32647391 DOI: 10.1007/s12088-020-00873-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 04/11/2020] [Indexed: 11/29/2022] Open
Abstract
Alternaria species are mainly saprophytic fungi, but some pathotypes of Alternaria alternata infect economically important plants including cereal crops, vegetables and fruits. Specially, A. alternata generates toxins which contaminate food and feed. To date, management of A. alternata relies primarily on fungicides. However, the control efficacy in most cases is below expectation due to ubiquity of A. alternata and resistance to fungicides. To mitigate resistance and develop long-lasting fungicides, uncovering multiple rather than single target is a prerequisite. Membrane proteins are potential targets of fungicides owing to wide participation in myriad biochemical events especially material transport, signal transduction and pathogenicity. However, so far, little is known about the distribution and molecular structure of A. alternata membrane proteins (AAMPs). Herein we summarize AAMPs by data mining and subsequent structure prediction. We also outline the state-of-the-art research advances of AAMPs especially those closely related to pathogenicity. Overall, this review aims to portray a picture of AAMPs and provide valuable insights for future development of highly efficient fungicides towards A. alternata or beyond.
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Affiliation(s)
- Ruyi Wang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029 People's Republic of China
| | - Peng Zhao
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029 People's Republic of China
| | - Xizhen Ge
- College of Biochemical Engineering, Beijing Union University, Beijing, 100023 People's Republic of China
| | - Pingfang Tian
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029 People's Republic of China
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28
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Mahmoudi Z, Rasooli I, Jahangiri A, Darvish Alipour Astaneh S. Prevention of nosocomial Acinetobacter baumannii infections with a conserved immunogenic fimbrial protein. APMIS 2020; 128:476-483. [PMID: 32445596 DOI: 10.1111/apm.13061] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 03/18/2020] [Indexed: 01/07/2023]
Abstract
Acinetobacter baumannii, one of the most life-threatening nosocomial drug-resistant pathogens, imposes high morbidity and mortality rates, thus highlighting immunization-based treatments or prevention measures. The selection of appropriate antigens can elicit protective immunity. The gene encoding a fimbrial protein introduced via reverse vaccinology was cloned, expressed and evaluated for immunogenicity in a murine model. Mice immunized with the recombinant protein were challenged with A. baumannii ATCC 19606. Adherence to A549 cell line of specific anti-sera treated A. baumannii was also assessed. Passive immunity was evaluated in a murine pneumonia model. Indirect ELISA showed a high specific antibody titre. Adherence of A. baumannii to A549 cell line decreased by 40% after incubation with 1:250 dilution of specific anti-sera. All the actively immunized mice survived. Bacterial load in the spleen and liver of the immunized mice was 3-fold lower than those of the control. The number of bacteria in the lungs of passively immunized mice was about 6-fold lower than the control mice. The fimbrial protein could be considered as a promising protective immunogen against A. baumannii.
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Affiliation(s)
| | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran.,Molecular Microbiology Research Center, Shahed University, Tehran, Iran
| | - Abolfazl Jahangiri
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
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29
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Fereshteh S, Abdoli S, Shahcheraghi F, Ajdary S, Nazari M, Badmasti F. New putative vaccine candidates against Acinetobacter baumannii using the reverse vaccinology method. Microb Pathog 2020; 143:104114. [DOI: 10.1016/j.micpath.2020.104114] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/15/2020] [Accepted: 03/01/2020] [Indexed: 01/15/2023]
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30
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Abstract
Acinetobacter baumannii is one of the most problematic pathogens in clinical settings. Emerging of its antibiotic-resistant strains persuade researchers to find alternative treatment options such as immunization against the notorious nosocomial pathogen. Oma87 has been introduced as an immunogenic outer membrane protein via reverse vaccinology. However, protectivity of A. baumannii Oma87 is not well known. The current research undertakes a study on the immunogenicity of recombinant Oma87 in a murine model. Some physico-chemical properties were assessed via in silico analyses. The corresponding gene was amplified and cloned into pET28a plasmid. The recombinant protein was purified and then was administered to immunize mice. Sera obtained from the immunized mice were assessed with respect to the triggered antibodies. Challenges were performed on actively or passively immunized mice. In silico analyses revealed that this protein is the same as BamA. A high titer of specific antibody was raised against rOma87 even after the first injection. The specific antibody recognized the whole cell of A. baumannii. Both active and passive immunizations confer 100 and 50% protection, respectively against ~ 2 × lethal dose (LD) of A. baumannii in the murine sepsis model. Although none of mice received ~ 5 × LD of A. baumannii survived in passive immunization, 25% of mice challenged with ~ 7 × LD of the bacteria survived and the dead mice exhibited a delayed death. Based on these results, Oma87 is the same as BamA which could be considered as a promising vaccine candidate against A. baumannii in the sepsis model.
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31
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Aghajani Z, Rasooli I, Mousavi Gargari SL. Exploitation of two siderophore receptors, BauA and BfnH, for protection against Acinetobacter baumannii infection. APMIS 2019; 127:753-763. [PMID: 31512768 DOI: 10.1111/apm.12992] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 08/19/2019] [Indexed: 01/30/2023]
Abstract
Iron uptake system is expressed in early stages of Acinetobacter baumannii infections under iron-restricted conditions. This study is aimed at the evaluation of immuno-protectivity of BfnH in comparison with BauA in both mature and selected fragmental proteins. The study was designed in single and combined forms of antigens. BfnH is presented in 3472 strains of A. baumannii with more than 97% identity. The preliminary immune-informatics analysis of this protein indicated a region from the β-barrel domain including exposed loops 2-5, with antigenic score comparable to that of BfnH. There was a significant rise in the specific IgG response in all test groups. The bacterial challenge with a lethal dose of A. baumannii demonstrated partial protection of whole proteins which coincides with a significant reduction in the bacterial population colonized in the main organs and an increase in the survival level. Passive immunization of the mice brought about 50% survival in the mice groups immunized with BfnH and with a combination of BfnH and BauA. The protectivity of siderophore receptors suggests their potential immunogenic role that could be considered as a component of multivalent subunit vaccine candidates against A. baumannii.
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Affiliation(s)
| | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran.,Molecular Microbiology Research Center, Shahed University, Tehran, Iran
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32
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Sharma P, Garg N, Sharma A, Capalash N, Singh R. Nucleases of bacterial pathogens as virulence factors, therapeutic targets and diagnostic markers. Int J Med Microbiol 2019; 309:151354. [PMID: 31495663 DOI: 10.1016/j.ijmm.2019.151354] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/12/2019] [Accepted: 08/29/2019] [Indexed: 12/25/2022] Open
Abstract
New frontiers of therapy are being explored against the upcoming bacterial diseases rendered untreatable due to multiple, extreme and pan- antibiotic resistance. Nucleases are ubiquitous in bacterial pathogens performing various functions like acquiring nucleotide nutrients, allowing or preventing uptake of foreign DNA, controlling biofilm formation/dispersal/architecture, invading host by tissue damage, evading immune defence by degrading DNA matrix of neutrophil extracellular traps (NETs) and immunomodulating the host immune response. Secretory nucleases also provide means of survival to other bacteria like iron-reducing Shewanella and such functions help them adapt and survive proficiently. Other than their pro-pathogen roles in survival, nucleases can be used directly as therapeutics. One of the powerful armours of pathogens is the formation of biofilms, thus helping them resist and persist in the harshest of environments. As eDNA forms the structural and binding component of biofilm, nucleases can be used against the adhering component, thus increasing the permeability of antimicrobial agents. Nucleases have recently become a model system of intense study for their biological functions and medical applications in diagnosis, immunoprophylaxis and therapy. Rational implications of these enzymes can impact human medicine positively in future by opening new ways for therapeutics which have otherwise reached saturation due to multi drug resistance.
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Affiliation(s)
- Prince Sharma
- Department of Microbiology, Panjab University, Chandigarh, India.
| | - Nisha Garg
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Anshul Sharma
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Neena Capalash
- Department of Biotechnology, Panjab University, Chandigarh, India
| | - Ravinder Singh
- Department of Microbiology, Panjab University, Chandigarh, India
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33
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Morris FC, Dexter C, Kostoulias X, Uddin MI, Peleg AY. The Mechanisms of Disease Caused by Acinetobacter baumannii. Front Microbiol 2019; 10:1601. [PMID: 31379771 PMCID: PMC6650576 DOI: 10.3389/fmicb.2019.01601] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 06/26/2019] [Indexed: 01/29/2023] Open
Abstract
Acinetobacter baumannii is a Gram negative opportunistic pathogen that has demonstrated a significant insurgence in the prevalence of infections over recent decades. With only a limited number of “traditional” virulence factors, the mechanisms underlying the success of this pathogen remain of great interest. Major advances have been made in the tools, reagents, and models to study A. baumannii pathogenesis, and this has resulted in a substantial increase in knowledge. This article provides a comprehensive review of the bacterial virulence factors, the host immune responses, and animal models applicable for the study of this important human pathogen. Collating the most recent evidence characterizing bacterial virulence factors, their cellular targets and genetic regulation, we have encompassed numerous aspects important to the success of this pathogen, including membrane proteins and cell surface adaptations promoting immune evasion, mechanisms for nutrient acquisition and community interactions. The role of innate and adaptive immune responses is reviewed and areas of paucity in our understanding are highlighted. Finally, with the vast expansion of available animal models over recent years, we have evaluated those suitable for use in the study of Acinetobacter disease, discussing their advantages and limitations.
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Affiliation(s)
- Faye C Morris
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Carina Dexter
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Xenia Kostoulias
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Muhammad Ikhtear Uddin
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Anton Y Peleg
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia.,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, VIC, Australia
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34
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Bolourchi N, Shahcheraghi F, Shirazi AS, Janani A, Bahrami F, Badmasti F. Immunogenic reactivity of recombinant PKF and AbOmpA proteins as serum resistance factors against sepsis of Acinetobacter baumannii. Microb Pathog 2019; 131:9-14. [DOI: 10.1016/j.micpath.2019.03.031] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 03/23/2019] [Accepted: 03/25/2019] [Indexed: 01/20/2023]
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35
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Jahangiri A, Owlia P, Rasooli I, Salimian J, Derakhshanifar E, Naghipour Erami A, Darzi Eslam E, Darvish Alipour Astaneh S. Specific egg yolk antibodies (IgY) confer protection against Acinetobacter baumannii in a murine pneumonia model. J Appl Microbiol 2018; 126:624-632. [PMID: 30353977 DOI: 10.1111/jam.14135] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/29/2018] [Accepted: 10/15/2018] [Indexed: 11/30/2022]
Abstract
AIM Acinetobacter baumannii, an increasingly serious health threat, is considered as one of the six most dangerous microbes of high mortality rate. However, treatment of its infections is difficult because of the lack of efficient antibiotic or commercial vaccines. Passive immunization through administration of specific antibodies such as IgY, could be an attractive practical solution. METHODS AND RESULTS In the current study, antigenicity of two recombinant outer membrane proteins (OmpA and Omp34) as well as inactivated whole cell of A. baumannii was assessed by ELISA. Moreover, prophylactic effects of specific IgY antibodies (avian antibody) raised against these antigens were evaluated in a murine pneumonia model. The specific IgY antibodies had various prophylactic effects in the pneumonia model. OmpA was the most potent antigen in terms of triggering antibody and conferring protection. While a synergic effect was observed in ELISA for antibodies raised against a combination of OmpA and Omp34 (which are known as Omp33-36 and Omp34 kDa), an antagonistic effect was unexpectedly seen in challenges. The reason for this phenomenon remains to be precisely addressed. CONCLUSION All the specific IgY antibodies could protect mice against pneumonia caused by A. baumannii. SIGNIFICANCE AND IMPACT OF THE STUDY The specific IgY antibodies could be employed as a pharmaceutical against pneumonia caused by A. baumannii.
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Affiliation(s)
- A Jahangiri
- Department of Biology, Shahed University, Tehran, Iran.,Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - P Owlia
- Molecular Microbiology Research Center, Shahed University, Tehran, Iran.,Department of Microbiology, Shahed University Faculty of Medical Sciences, Tehran, Iran
| | - I Rasooli
- Department of Biology, Shahed University, Tehran, Iran.,Molecular Microbiology Research Center, Shahed University, Tehran, Iran
| | - J Salimian
- Chemical Injuries Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | | | | | - E Darzi Eslam
- Department of Biology, Shahed University, Tehran, Iran
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36
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Novović K, Mihajlović S, Dinić M, Malešević M, Miljković M, Kojić M, Jovčić B. Acinetobacter spp. porin Omp33-36: Classification and transcriptional response to carbapenems and host cells. PLoS One 2018; 13:e0201608. [PMID: 30071077 PMCID: PMC6072067 DOI: 10.1371/journal.pone.0201608] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 07/18/2018] [Indexed: 01/11/2023] Open
Abstract
Acinetobacter baumannii has been recognized as one of the most challeging pathogens in clinical settings worldwide. Outer membrane porins play a significant role in Acinetobacter antibiotic resistance and virulence. A. baumannii carbapenem resistance and virulence factor porin Omp33-36 was the subject of this study. We investigated the omp33-36 gene transcriptional response in the growth phase, its response to carbapenems, and the effect of contact with host cells. Additionally, the cytotoxic effect of A. baumannii towards keratinocytes was assessed, as well as correlation between omp33-36 gene transcription and cytotoxicity. Further, Acinetobacter spp. Omp33-36 was classified and its characteristics relevant for vaccine candidature were determined. The level of the omp33-36 gene transcription varied between growth phases, but a common pattern could not be established among different strains. Treatment with subinhibitory concentrations of carbapenems decreased, while contact with keratinocytes increased omp33-36 expression in the analysed A. baumannii strains. Variations in omp33-36 mRNA levels did not correlate with cytotoxicity levels. Decrease of omp33-36 mRNA during treatment with subinhibitory concentrations of carbapenems, indicated the importance of transcriptional changes in reversible resistance to carbapenems due to the absence of Omp33-36. The transcription of omp33-36 increased after contact with keratinocytes, indicating the important role of de novo transcription during the initial phase of A. baumannii infection. Primary structural analysis of Acinetobacter spp. Omp33-36 revealed three distinct groups (among four A. baumannii variants). Although we have shown that Omp33-36 was highly polymorphic, we propose a potential antigen (PLAEAAFL motif) for vaccine development. According to PROVEAN analysis, the highly polymorphic structure of Omp33-36 porin should not influence its function significantly.
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Affiliation(s)
- Katarina Novović
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Sanja Mihajlović
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Miroslav Dinić
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Milka Malešević
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Marija Miljković
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Milan Kojić
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Branko Jovčić
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
- * E-mail:
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37
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Droppa-Almeida D, Franceschi E, Padilha FF. Immune-Informatic Analysis and Design of Peptide Vaccine From Multi-epitopes Against Corynebacterium pseudotuberculosis. Bioinform Biol Insights 2018; 12:1177932218755337. [PMID: 29780242 PMCID: PMC5954444 DOI: 10.1177/1177932218755337] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 01/04/2018] [Indexed: 01/15/2023] Open
Abstract
Caseous lymphadenitis (CLA) is a disease caused by Corynebacterium pseudotuberculosis bacteria that affects sheep and goats. The absence of a serologic diagnose is a factor that contributes for the disease dissemination, and due to the formation of granuloma, the treatment is very expensive. Therefore, prophylaxis is the approach with best cost-benefit relation; however, it still lacks an effective vaccine. In this sense, this work seeks to apply bioinformatic tools to design an effective vaccine against CLA, using CP40 protein as standard for the design of immunodominant epitopes, from which a total of 6 sequences were obtained, varying from 10 to 16 amino acid residues. The evaluation of different properties of the vaccines showed that the vaccine is a potent and nonallergenic antigen remaining stable in a wide range of temperatures. The initial tertiary structure of the vaccine was then predicted and a model selected. Later, the process of CP40 protein and TLR2 receptor binding was performed, presenting interaction with this receptor, which plays an important role in the activation of the immune response.
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Affiliation(s)
| | - Elton Franceschi
- Nucleus of Studies in Colloidal Systems, Universidade Tiradentes, Aracaju, Brazil
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38
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Ahmad S, Azam SS. A novel approach of virulome based reverse vaccinology for exploring and validating peptide-based vaccine candidates against the most troublesome nosocomial pathogen: Acinetobacter baumannii. J Mol Graph Model 2018; 83:1-11. [PMID: 29753164 DOI: 10.1016/j.jmgm.2018.04.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 04/27/2018] [Accepted: 04/30/2018] [Indexed: 12/12/2022]
Abstract
Acinetobacter baumannii is one of the major cause of nosocomial infections around the globe. The emergence of hyper-virulent strains of the pathogen greatly narrows down therapeutic options for patients infected with this red alert superbug. Development of a peptide-based vaccine can offers an alternative, attractive, and cost-effective remedy for multidrug-resistant A. baumannii associated complications. Herein, we introduced a novel virulome based Reverse Vaccinology for screening peptide based vaccine candidates against A. baumannii and its validation using a negative control. The pipeline screened "FYLNDQPVS" of polysaccharide export outer membrane protein (EpsA) and "LQNNTRRMK" of chaperone-usher pathway protein B (CsuB) as broad-spectrum peptides for induction of targeted immune responses. The 9-mer epitope of both proteins was rendered virulent, antigenic, non-allergen, and highly conserved among thirty-four completely annotated strains. Interactome examination unravels peptides protein direct and indirect interactions with biological significant pathways, essential for A. baumannii pathogenesis and survival. Protein-peptide docking aids in addition by unveiling deep binding of the epitopes in the active site of the most prevalent binding allele in the human population-the DRB1*0101. Both the proteins till to date are not characterized for immunoprotective efficacy and desirable to be deciphered experimentally. The designed series of in silico filters rejected few recently reported peptide and non-peptide vaccine targets and has delivered outcomes, which we believe will enrich the existing knowledge of vaccinology against this life-threatening human pathogen.
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Affiliation(s)
- Sajjad Ahmad
- Computational Biology Lab, National Center for Bioinformatics (NCB), Quaid-i-Azam University, Islamabad, Pakistan.
| | - Syed Sikander Azam
- Computational Biology Lab, National Center for Bioinformatics (NCB), Quaid-i-Azam University, Islamabad, Pakistan.
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39
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Kazi A, Chuah C, Majeed ABA, Leow CH, Lim BH, Leow CY. Current progress of immunoinformatics approach harnessed for cellular- and antibody-dependent vaccine design. Pathog Glob Health 2018. [PMID: 29528265 DOI: 10.1080/20477724.2018.1446773] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
Immunoinformatics plays a pivotal role in vaccine design, immunodiagnostic development, and antibody production. In the past, antibody design and vaccine development depended exclusively on immunological experiments which are relatively expensive and time-consuming. However, recent advances in the field of immunological bioinformatics have provided feasible tools which can be used to lessen the time and cost required for vaccine and antibody development. This approach allows the selection of immunogenic regions from the pathogen genomes. The ideal regions could be developed as potential vaccine candidates to trigger protective immune responses in the hosts. At present, epitope-based vaccines are attractive concepts which have been successfully trailed to develop vaccines which target rapidly mutating pathogens. In this article, we provide an overview of the current progress of immunoinformatics and their applications in the vaccine design, immune system modeling and therapeutics.
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Affiliation(s)
- Ada Kazi
- a Institute for Research in Molecular Medicine (INFORMM) , Universiti Sains Malaysia , Kelantan , Malaysia.,b School of Health Sciences , Universiti Sains Malaysia , Kelantan , Malaysia
| | - Candy Chuah
- c School of Medical Sciences , Universiti Sains Malaysia , Kelantan , Malaysia
| | | | - Chiuan Herng Leow
- d Institute for Research in Molecular Medicine (INFORMM) , Universiti Sains Malaysia , Penang , Malaysia
| | - Boon Huat Lim
- b School of Health Sciences , Universiti Sains Malaysia , Kelantan , Malaysia
| | - Chiuan Yee Leow
- a Institute for Research in Molecular Medicine (INFORMM) , Universiti Sains Malaysia , Kelantan , Malaysia
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40
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Future Directions and Molecular Basis of Ventilator Associated Pneumonia. Can Respir J 2017; 2017:2614602. [PMID: 29162982 PMCID: PMC5661065 DOI: 10.1155/2017/2614602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 09/14/2017] [Indexed: 12/26/2022] Open
Abstract
Mechanical ventilation is a lifesaving treatment and has complications such as ventilator associated pneumonia (VAP) that lead to high morbidity and mortality. Moreover VAP is the second most common hospital-acquired infection in pediatric intensive care units. Although it is still not well understood, understanding molecular pathogenesis is essential for preventing and treating pneumonia. A lot of microbes are detected as a causative agent of VAP. The most common isolated VAP pathogens in pediatric patients are Staphylococcus aureus, Pseudomonas aeruginosa, and other gram negative bacteria. All of the bacteria have different pathogenesis due to their different virulence factors and host reactions. This review article focused on mechanisms of VAP with molecular pathogenesis of the causative bacteria one by one from the literature. We hope that we know more about molecular pathogenesis of VAP and we can investigate and focus on the management of the disease in near future.
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Immunoprotective potential of BamA, the outer membrane protein assembly factor, against MDR Acinetobacter baumannii. Sci Rep 2017; 7:12411. [PMID: 28963492 PMCID: PMC5622086 DOI: 10.1038/s41598-017-12789-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 09/19/2017] [Indexed: 12/19/2022] Open
Abstract
Acinetobacter baumannii infections are responsible for major health problems in immunocompromised patients particularly in intensive care units. Due to rapid acquisition of and also inherent drug resistance, a vaccine is an effective treatment option against this pathogen. BamA, an outer membrane β-barrel assembly protein, was identified in A. baumannii as potential vaccine candidate by in silico analysis. The immunoprotective efficacy of this highly conserved protein was investigated against a virulent multidrug resistant clinical isolate using murine pneumonia model. Recombinant BamA elicited a high IgG antibody titer (160000) in mice. Opsonophagocytic killing assay showed non-neutrilizing, opsonizing antibodies with combinatorial bactericidal activity of antibodies and complement components. Active and passive immunization protected 80 and 60% mice respectively against intranasal challenge with lethal dose (109 CFU) of virulent A. baumannii along with efficient clearance of bacteria in mice lungs and reduction in levels of pro-inflammatory cytokines viz. TNF-α, IL-6 and IL-1β in sera and lung tissue homogenate. Increase in levels of IL-10, an anti-inflammatory cytokine and reduction of neutrophils in lungs facilitated the control of infection. This study demonstrates the potential of BamA as effective vaccine candidate and a promising target for antibody-based therapy to protect against MDR A. baumannii infections.
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Clinical and Pathophysiological Overview of Acinetobacter Infections: a Century of Challenges. Clin Microbiol Rev 2017; 30:409-447. [PMID: 27974412 DOI: 10.1128/cmr.00058-16] [Citation(s) in RCA: 626] [Impact Index Per Article: 89.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Acinetobacter is a complex genus, and historically, there has been confusion about the existence of multiple species. The species commonly cause nosocomial infections, predominantly aspiration pneumonia and catheter-associated bacteremia, but can also cause soft tissue and urinary tract infections. Community-acquired infections by Acinetobacter spp. are increasingly reported. Transmission of Acinetobacter and subsequent disease is facilitated by the organism's environmental tenacity, resistance to desiccation, and evasion of host immunity. The virulence properties demonstrated by Acinetobacter spp. primarily stem from evasion of rapid clearance by the innate immune system, effectively enabling high bacterial density that triggers lipopolysaccharide (LPS)-Toll-like receptor 4 (TLR4)-mediated sepsis. Capsular polysaccharide is a critical virulence factor that enables immune evasion, while LPS triggers septic shock. However, the primary driver of clinical outcome is antibiotic resistance. Administration of initially effective therapy is key to improving survival, reducing 30-day mortality threefold. Regrettably, due to the high frequency of this organism having an extreme drug resistance (XDR) phenotype, early initiation of effective therapy is a major clinical challenge. Given its high rate of antibiotic resistance and abysmal outcomes (up to 70% mortality rate from infections caused by XDR strains in some case series), new preventative and therapeutic options for Acinetobacter spp. are desperately needed.
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Patel S. Drivers of bacterial genomes plasticity and roles they play in pathogen virulence, persistence and drug resistance. INFECTION GENETICS AND EVOLUTION 2016; 45:151-164. [DOI: 10.1016/j.meegid.2016.08.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 08/26/2016] [Accepted: 08/27/2016] [Indexed: 12/11/2022]
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Singh R, Garg N, Shukla G, Capalash N, Sharma P. Immunoprotective Efficacy of Acinetobacter baumannii Outer Membrane Protein, FilF, Predicted In silico as a Potential Vaccine Candidate. Front Microbiol 2016; 7:158. [PMID: 26904021 PMCID: PMC4751259 DOI: 10.3389/fmicb.2016.00158] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/29/2016] [Indexed: 11/22/2022] Open
Abstract
Acinetobacter baumannii is emerging as a serious nosocomial pathogen with multidrug resistance that has made it difficult to cure and development of efficacious treatment against this pathogen is direly needed. This has led to investigate vaccine approach to prevent and treat A. baumannii infections. In this work, an outer membrane putative pilus assembly protein, FilF, was predicted as vaccine candidate by in silico analysis of A. baumannii proteome and was found to be conserved among the A. baumannii strains. It was cloned and expressed in E. coli BL21(DE3) and purified by Ni-NTA chromatography. Immunization with FilF generated high antibody titer (>64,000) and provided 50% protection against a standardized lethal dose (108 CFU) of A. baumannii in murine pneumonia model. FilF immunization reduced the bacterial load in lungs by 2 and 4 log cycles, 12 and 24 h post infection as compared to adjuvant control; reduced the levels of pro-inflammatory cytokines TNF-α, IL-6, IL-33, IFN-γ, and IL-1β significantly and histology of lung tissue supported the data by showing considerably reduced damage and infiltration of neutrophils in lungs. These results demonstrate the in vivo validation of immunoprotective efficacy of a protein predicted as a vaccine candidate by in silico proteomic analysis and open the possibilities for exploration of a large array of uncharacterized proteins.
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Affiliation(s)
- Ravinder Singh
- Department of Microbiology, Panjab University Chandigarh, India
| | - Nisha Garg
- Department of Microbiology, Panjab University Chandigarh, India
| | - Geeta Shukla
- Department of Microbiology, Panjab University Chandigarh, India
| | - Neena Capalash
- Department of Biotechnology, Panjab University Chandigarh, India
| | - Prince Sharma
- Department of Microbiology, Panjab University Chandigarh, India
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