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Xu Y, Zhu F, Zhou Z, Ma S, Zhang P, Tan C, Luo Y, Qin R, Chen J, Pan P. A novel mRNA multi-epitope vaccine of Acinetobacter baumannii based on multi-target protein design in immunoinformatic approach. BMC Genomics 2024; 25:791. [PMID: 39160492 PMCID: PMC11334330 DOI: 10.1186/s12864-024-10691-7] [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: 05/13/2024] [Accepted: 08/06/2024] [Indexed: 08/21/2024] Open
Abstract
Acinetobacter baumannii is a gram-negative bacillus prevalent in nature, capable of thriving under various environmental conditions. As an opportunistic pathogen, it frequently causes nosocomial infections such as urinary tract infections, bacteremia, and pneumonia, contributing to increased morbidity and mortality in clinical settings. Consequently, developing novel vaccines against Acinetobacter baumannii is of utmost importance. In our study, we identified 10 highly conserved antigenic proteins from the NCBI and UniProt databases for epitope mapping. We subsequently screened and selected 8 CTL, HTL, and LBL epitopes, integrating them into three distinct vaccines constructed with adjuvants. Following comprehensive evaluations of immunological and physicochemical parameters, we conducted molecular docking and molecular dynamics simulations to assess the efficacy and stability of these vaccines. Our findings indicate that all three multi-epitope mRNA vaccines designed against Acinetobacter baumannii are promising; however, further animal studies are required to confirm their reliability and effectiveness.
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Affiliation(s)
- Yizhong Xu
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fei Zhu
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ziyou Zhou
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shiyang Ma
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Peipei Zhang
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Caixia Tan
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yuying Luo
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Rongliu Qin
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jie Chen
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China.
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China.
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | - Pinhua Pan
- Department of Respiratory Medicine, National Key Clinical Specialty, Branch of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Center of Respiratory Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China.
- Clinical Research Center for Respiratory Diseases in Hunan Province, Changsha, Hunan, China.
- Hunan Engineering Research Center for Intelligent Diagnosis and Treatment of Respiratory Disease, Changsha, Hunan, China.
- Department of Infection Control Center of Xiangya Hospital, Central South University, Changsha, Hunan, China.
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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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Azimi L, Hasani H, Karimi A, Fahimzad SA, Fallah F, Fatehi S, Armin S, Sadr M. Characterization of genes involved in the iron acquisition system of multidrug-resistant Acinetobacter baumannii. GMS HYGIENE AND INFECTION CONTROL 2024; 19:Doc25. [PMID: 38883402 PMCID: PMC11177110 DOI: 10.3205/dgkh000480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Background The high prevalence of virulence-associated genes observed in Acinetobacter baumannii isolates underscores the pathogenic potential of this bacterium. The presence of these genes confers enhanced survival, evasion of host defenses, and increased virulence. In this study, we investigate the presence and distribution of genes associated with virulence and assess the antimicrobial susceptibility patterns in clinical isolates of A. baumannii. Materials and method This research focused on examining the 50 multi-drugs resistant (MDR) strains that were included in this investigation. The identification of these strains was validated using Oxa-51. The presence of the BauA and BasD genes was determined through conventional PCR techniques. Results The results derived from Oxa-51 PCR confirmed the identification of all 50 selected strains of A. baumannii. Additionally, both the BauA and BasD genes were successfully identified in 82% of the MDR strains. Conclusion Moreover, the varying antibiotic resistance patterns highlight the challenge in treating A. baumannii infections effectively. Strategies such as combination therapy, antimicrobial stewardship, and infection control measures should be considered to combat this multidrug-resistant pathogen.
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Affiliation(s)
- Leila Azimi
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hadi Hasani
- Department of Medical Surgical Nursing, Jovein School of Nursing, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Abdollah Karimi
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Alireza Fahimzad
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Fallah
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shima Fatehi
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahnaz Armin
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammadreza Sadr
- Department of Pediatrics, School of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran
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Mansouri M, Sadeghpoor M, Jahangiri A, Ghaini MH, Rasooli I. Enhanced immunoprotection against Acinetobacter baumannii infection: Synergistic effects of Bap and BauA in a murine model. Immunol Lett 2023; 262:18-26. [PMID: 37652189 DOI: 10.1016/j.imlet.2023.08.004] [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: 05/31/2023] [Revised: 08/26/2023] [Accepted: 08/28/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND The rise of multi-drug resistant Acinetobacter baumannii poses a grave threat to hospital settings, resulting in increased mortality rates and garnering global attention. The formation of biofilms facilitated by biofilm-associated protein (Bap) and the iron absorption capabilities mediated by Baumannii acinetobactin utilization A (BauA) contribute to the persistence and survival of multidrug-resistant strains. In this study, we aimed to investigate the potential of disrupting the function of BauA and Bap simultaneously as a strategy for controlling A. baumannii. METHODS Recombinant Bap and BauA were expressed, purified, and subcutaneously administered individually and in combination to BALB/c mice. Subsequently, mice were intraperitoneally challenged with A. baumannii, and the bacterial load and tissue damage in the spleen, lung, and liver were assessed. Serum samples were evaluated to determine antibody titers in surviving mice. RESULTS Specific IgG antibodies were significantly increased. A combination of the antigens resulted in enhanced titer of specific IgGs in comparison to either BauA or Bap alone. The antibodies remained stable over a seven-month period. The combination of Bap and BauA exhibited superior immunoprotection against A. baumannii infection compared to individual administration, resulting in a further reduction in bacterial load in the liver, spleen, and lungs. The histopathological analysis demonstrated successful protection of the tissues against A. baumannii-induced damage upon administration of the two immunogens. CONCLUSIONS The combination of Bap and BauA has the potential to target a broader range of A. baumannii strains, including those expressing either Bap or BauA, thereby increasing its efficacy against a diverse array of strains.
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Affiliation(s)
| | | | - Abolfazl Jahangiri
- Applied Microbiology Research Center, Systems biology and poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | | | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran; Molecular Microbiology Research Center and Department of Biology, Shahed University, Tehran, Iran.
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Mansouri M, Sadeghpoor M, Abdollahi M, Vafaei AJ, Jalali Nadoushan M, Rasooli I. Synergistic immunoprotection by Oma87 and Bap against Acinetobacter baumannii sepsis model. Int Immunopharmacol 2023; 122:110650. [PMID: 37454632 DOI: 10.1016/j.intimp.2023.110650] [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: 05/20/2023] [Revised: 07/03/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Acinetobacter baumannii is the leading cause of nosocomial infection. A surface protein commonly known as biofilm associate protein (Bap) has been identified in a bloodstream isolate of A. baumannii. Bap of A. baumannii is involved in intercellular adhesion within the mature biofilm. Outer membrane protein Acinetobacter 87 kDa (Oma87) or β-barrel assembly machinery A (BamA) has been introduced as an immunogenic outer membrane protein via in silico reverse vaccinology. Current research examines the synergistic effect of immunization of mice with both recombinant proteins viz., Oma87 and Bap. Antibodies were raised to the proteins. The mice were challenged with A. baumannii ATCC 19606 and the bacterial burden was enumerated in the mice's livers, spleens, and lungs followed by histological examination. IgG levels significantly increased, and a significant (p < 0.0001) difference was observed between bacterial burdens in the internal organs of the actively and passively immunized groups. Female BALB/c mice weighing 20-25 g, were divided into 4 groups of 14 mice each viz., control, Oma87, Bap, Oma87-Bap groups. The proteins were individually immunogenic, but the combination of both proteins had a synergistic protection property. This is further supported by the histological examination. Based on the results, the combination of Oma87 and Bap may be considered a promising vaccine candidate against A. baumannii .
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Affiliation(s)
- Mobina Mansouri
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | - Masoomeh Sadeghpoor
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | - Marziyeh Abdollahi
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | - Amir Javad Vafaei
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
| | | | - Iraj Rasooli
- Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran; Molecular Microbiology Research Center and Department of Biology, Shahed University, Tehran, Iran.
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Mirali M, Jahangiri A, Jalali Nadoushan M, Rasooli I. A two-protein cocktail elicits a protective immune response against Acinetobacter baumannii in a murine infection model. Microb Pathog 2023; 182:106262. [PMID: 37474079 DOI: 10.1016/j.micpath.2023.106262] [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: 03/30/2023] [Revised: 07/05/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023]
Abstract
PURPOSE Due to its high drug resistance, Acinetobacter baumannii is a priority for new therapeutic measures like vaccines. In this study, the protectivity of a combination cocktail of Omp34 and BauA as a vaccine against A. baumannii was studied in a murine sepsis model. METHODS The antibody titers were raised to Omp34 and BauA in BALB/c mice and assessed by indirect ELISA. The immunized mice were challenged with A. baumannii ATCC 19606. The bacterial loads in the liver, spleen, and lungs were also determined. RESULTS A significant increase in survival of the immunized mice was noted. In active immunity, the survival rates in mice receiving Omp34 and BauA alone or in combination were 100%. A significant decrease in the bacterial load was observed in the spleens, livers, and lungs of vaccinated mice. Anti-BauA and anti-Omp34 sera crossly detected Omp34 and BauA respectively. The decrease in bacterial load in body organs of mice vaccinated with a combination of the two proteins was significantly higher than those of the single proteins in both actively and passively immunized mice. In passive immunity, the survival rate of mice receiving specific sera raised to the combination of these proteins was 85.7%. CONCLUSION Higher protection by a combination of Omp34 and BauA than Omp34 or BauA could be attributed to targeting simultaneously both surface antigens indicating the synergistic effect of Omp34 and BauA as suitable vaccine candidates in the prevention or treatment of A. baumannii infections.
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Affiliation(s)
| | - Abolfazl Jahangiri
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Mohammadreza Jalali Nadoushan
- Department of Pathology, School of Medicine, Shahed University, Tehran, Iran; Molecular Microbiology Research Center and Department of Biology, Shahed University, Tehran, Iran.
| | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran; Molecular Microbiology Research Center and Department of Biology, Shahed University, Tehran, Iran.
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MatRahim NA, Jones KM, Keegan BP, Strych U, Zhan B, Lee HY, AbuBakar S. TonB-Dependent Receptor Protein Displayed on Spores of Bacillus subtilis Stimulates Protective Immune Responses against Acinetobacter baumannii. Vaccines (Basel) 2023; 11:1106. [PMID: 37376495 DOI: 10.3390/vaccines11061106] [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: 04/19/2023] [Revised: 06/06/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
The emergence of antibiotic-resistant Acinetobacter baumannii strains with limited treatment options has become a significant global health concern. Efforts to develop vaccines against the bacteria have centred on several potential protein targets, including the TonB-dependent receptors (TBDRs). In the present study, TBDRs from A. baumannii were displayed on the surface of Bacillus subtilis spores. The immunogenicity of the recombinant spores was evaluated in orally vaccinated mice. None of the immunized mice demonstrated signs of illness and were observed to be healthy throughout the study. Sera and the intestinal secretions from the recombinant spores-treated mice demonstrated mucosal and humoral antibody responses to the vaccine antigen. In addition, bactericidal activities of the sera against A. baumannii clinical isolates were demonstrated. These observations suggest that the B. subtilis spore-displayed TBDRs should be further explored as much-needed potential oral vaccine candidates against A. baumannii.
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Affiliation(s)
- Nor-Aziyah MatRahim
- Tropical Infectious Diseases Research and Education Center (TIDREC), Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX 77030, USA
- Virology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institutes of Health, Shah Alam 40170, Malaysia
| | - Kathryn Marie Jones
- Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX 77030, USA
| | - Brian P Keegan
- Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ulrich Strych
- Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX 77030, USA
| | - Bin Zhan
- Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hai-Yen Lee
- Tropical Infectious Diseases Research and Education Center (TIDREC), Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Sazaly AbuBakar
- Tropical Infectious Diseases Research and Education Center (TIDREC), Universiti Malaya, Kuala Lumpur 50603, Malaysia
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The Prevalence of Virulence Factor Genes among Carbapenem-Non-Susceptible Acinetobacter baumannii Clinical Strains and Their Usefulness as Potential Molecular Biomarkers of Infection. Diagnostics (Basel) 2023; 13:diagnostics13061036. [PMID: 36980344 PMCID: PMC10047099 DOI: 10.3390/diagnostics13061036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/25/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023] Open
Abstract
Healthcare-associated infections caused by multidrug-resistant Acinetobacter baumannii strains are a serious global threat. Therefore, it is important to expand the knowledge on the mechanisms of pathogenicity of these particular bacteria. The aim of this study was to assess the distribution of selected virulence factor genes (bap, surA1, omp33-36, bauA, bauS, and pld) among carbapenem-non-susceptible clinical A. baumannii isolates and to evaluate their potential usefulness as genetic markers for rapid diagnostics of A. baumannii infections. Moreover, we aimed to compare the virulence genes prevalence with the occurrence of carbapenemases genes. A total of 100 carbapenem-non-susceptible A. baumannii clinical isolates were included in the study. The presence of virulence factors and blaOXA genes was evaluated by real-time PCR. The occurrence of virulence factors genes was as follows: 100.0% for the bap and surA1 genes, 99.0% for the basD and pld genes. The bauA and omp33-36 genes were absent among the studied strains. The predominant genes (bap and surA1) are involved in biofilm formation and their presence among all clinical strains can be applied as a genetic marker to recognize A. baumannii infection. High frequencies of the basD gene—involved in siderophore biosynthesis and the gene encoding phospholipase D (pld)—were also noted among blaOXA-positive strains, showing their potential role in a pathogenicity of blaOXA-positive A. baumannii clinical strains.
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Valcek A, Philippe C, Whiteway C, Robino E, Nesporova K, Bové M, Coenye T, De Pooter T, De Coster W, Strazisar M, Van der Henst C. Phenotypic Characterization and Heterogeneity among Modern Clinical Isolates of Acinetobacter baumannii. Microbiol Spectr 2023; 11:e0306122. [PMID: 36475894 PMCID: PMC9927488 DOI: 10.1128/spectrum.03061-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 11/22/2022] [Indexed: 12/13/2022] Open
Abstract
Acinetobacter baumannii is an opportunistic pathogenic bacterium prioritized by WHO and CDC because of its increasing antibiotic resistance. Heterogeneity among strains represents the hallmark of A. baumannii bacteria. We wondered to what extent extensively used strains, so-called reference strains, reflect the dynamic nature and intrinsic heterogeneity of these bacteria. We analyzed multiple phenotypic traits of 43 nonredundant, modern, and multidrug-resistant, extensively drug-resistant, and pandrug-resistant clinical isolates and broadly used strains of A. baumannii. Comparison of these isolates at the genetic and phenotypic levels confirmed a high degree of heterogeneity. Importantly, we observed that a significant portion of modern clinical isolates strongly differs from several historically established strains in the light of colony morphology, cellular density, capsule production, natural transformability, and in vivo virulence. The significant differences between modern clinical isolates of A. baumannii and established strains could hamper the study of A. baumannii, especially concerning its virulence and resistance mechanisms. Hence, we propose a variable collection of modern clinical isolates that are characterized at the genetic and phenotypic levels, covering a wide range of the phenotypic spectrum, with six different macrocolony type groups, from avirulent to hypervirulent phenotypes, and with naturally noncapsulated to hypermucoid strains, with intermediate phenotypes as well. Strain-specific mechanistic observations remain interesting per se, and established "reference" strains have undoubtedly been shown to be very useful to study basic mechanisms of A. baumannii biology. However, any study based on a specific strain of A. baumannii should be compared to modern and clinically relevant isolates. IMPORTANCE Acinetobacter baumannii is a bacterium prioritized by the CDC and WHO because of its increasing antibiotic resistance, leading to treatment failures. The hallmark of this pathogen is the high heterogeneity observed among isolates, due to a very dynamic genome. In this context, we tested if a subset of broadly used isolates, considered "reference" strains, was reflecting the genetic and phenotypic diversity found among currently circulating clinical isolates. We observed that the so-called reference strains do not cover the whole diversity of the modern clinical isolates. While formerly established strains successfully generated a strong base of knowledge in the A. baumannii field and beyond, our study shows that a rational choice of strain, related to a specific biological question, should be taken into consideration. Any data obtained with historically established strains should also be compared to modern and clinically relevant isolates, especially concerning drug screening, resistance, and virulence contexts.
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Affiliation(s)
- Adam Valcek
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Chantal Philippe
- Research Unit in the Biology of Microorganisms (URBM), NARILIS, University of Namur (UNamur), Namur, Belgium
| | - Clémence Whiteway
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Etienne Robino
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Kristina Nesporova
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Mona Bové
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tim De Pooter
- Neuromics Support Facility, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Wouter De Coster
- Applied and Translational Neurogenomics Group, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium
- Applied and Translational Neurogenomics Group, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Mojca Strazisar
- Neuromics Support Facility, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Charles Van der Henst
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
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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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11
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Ramezanalizadeh F, Rasooli I, Owlia P, Darvish Alipour Astaneh S, Abdolhamidi R. Vaccination with a combination of planktonic and biofilm virulence factors confers protection against carbapenem-resistant Acinetobacter baumannii strains. Sci Rep 2022; 12:19909. [PMID: 36402866 PMCID: PMC9675771 DOI: 10.1038/s41598-022-24163-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 11/10/2022] [Indexed: 11/21/2022] Open
Abstract
Acinetobacter baumannii is a multi-drug resistant pathogen with the ability to switch between planktonic and biofilm phenotypes. Although there is no vaccine against A. baumannii infections, many attempts have been made to develop vaccines using planktonic or biofilm antigens. To cover the different phenotypes of A. baumannii during growth and attachment, we combined planktonic upregulated antigens of iron receptors with biofilm upregulated antigens of pilus rods and evaluated immune responses and protective efficacies of the combined vaccine using lethal and sub-lethal murine sepsis models. The results showed that the combined vaccine elicited high IgG antibody titers and conferred protection against lethal doses of two Carbapenem-resistant high adherent A. baumannii strains. Complete bacterial clearance from all the affected tissues of the mice challenged with A. baumannii was an excellent achievement with our quadrivalent immunogen. These results demonstrate both planktonic and biofilm antigens are important during antigen selection for vaccine design.
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Affiliation(s)
| | - Iraj Rasooli
- Department of Biology, Shahed University, Tehran, Iran.
- Department of Biology, Molecular Microbiology Research Center, Shahed University, Tehran-Qom Express Way, Tehran, 3319118651, Iran.
| | - Parviz Owlia
- Department of Biology, Molecular Microbiology Research Center, Shahed University, Tehran-Qom Express Way, Tehran, 3319118651, Iran
| | - Shakiba Darvish Alipour Astaneh
- Department of Biotechnology, Semnan University, Central Administration of Semnan University, Campus 1, P.O. Box 35131-19111, Semnan, Islamic Republic of Iran
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12
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Tamehri M, Rasooli I, Pishgahi M, Jahangiri A, Ramezanalizadeh F, Banisaeed Langroodi SR. Combination of BauA and OmpA elicit immunoprotection against Acinetobacter baumannii in a murine sepsis model. Microb Pathog 2022; 173:105874. [DOI: 10.1016/j.micpath.2022.105874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 09/18/2022] [Accepted: 11/05/2022] [Indexed: 11/09/2022]
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13
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Bolourchi N, Fereshteh S, Noori Goodarzi N, Badmasti F. Subtractive genomic analysis for computational identification of putative immunogenic targets against clinical Enterobacter cloacae complex. PLoS One 2022; 17:e0275749. [PMID: 36228013 PMCID: PMC9560131 DOI: 10.1371/journal.pone.0275749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/22/2022] [Indexed: 11/06/2022] Open
Abstract
Background Enterobacter is a major nosocomial genus of Enterobacteriaceae responsible for a variety of nosocomial infections, particularly in prolonged hospitalized patients in the intensive care units. Since current antibiotics have failed treating colistin- and carbapenem-resistant Enterobacteriaceae, efforts are underway to find suitable alternative strategies. Therefore, this study conducted a reverse vaccinology (RV) to identify novel and putative immunogenic targets using core proteome of 20 different sequence types (STs) of clinical Enterobacter spp. Moreover, we introduced a structural-based approach for exploration of potential vaccine candidates against the Enterobacteriaceae family using their conserved domain analysis. Results A number of 2616 core coding sequences (CDSs) were retrieved from 20 clinical strains of Enterobacter spp. with a similarity of ≥ 50%. Nine proteins with a score of ≥ 20 considered as the shortlisted proteins based on the quartile scoring method, including three TonB-dependent receptors, WP_008500981.1, WP_058690971.1 and WP_058679571.1; one YjbH domain-containing protein, WP_110108068.1; three flagellar proteins, WP_088207510.1, WP_033145204.1 and WP_058679632.1; one spore-coat U domain-containing protein, WP_039266612.1; and one DD-metalloendopeptidase family protein, WP_025912449.1. In this study, proteins WP_058690971.1 and WP_110108068.1 were detected as the top candidates with regard to immune stimulation and interactions with TLRs. However, their efficacy is remaining to be evaluated experimentally. Conclusions Our investigation introduced common ferrichrome porins with high sequence similarity as potential vaccine candidates against the Enterobacteriaceae family. These proteins belong to the iron acquisition system and possess all criteria of suitable vaccine targets. Therefore, they need to be specifically paid attention for vaccine development against clinically important members of Enterobacteriaceae family.
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Affiliation(s)
- 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
| | - Farzad Badmasti
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
- Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
- * E-mail:
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mRNA Vaccine Designing Using Chikungunya Virus E Glycoprotein through Immunoinformatics-Guided Approaches. Vaccines (Basel) 2022; 10:vaccines10091476. [PMID: 36146554 PMCID: PMC9500984 DOI: 10.3390/vaccines10091476] [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: 08/07/2022] [Revised: 08/27/2022] [Accepted: 08/29/2022] [Indexed: 12/24/2022] Open
Abstract
Chikungunya virus is an alphavirus transmitted by mosquitos that develops into chikungunya fever and joint pain in humans. This virus’ name originated from a Makonde term used to describe an illness that changes the joints and refers to the posture of afflicted patients who are affected by excruciating joint pain. There is currently no commercially available drug or vaccine for chikungunya virus infection and the treatment is performed by symptom reduction. Herein, we have developed a computationally constructed mRNA vaccine construct featuring envelope glycoprotein as the target molecule to aid in the treatment process. We have utilized the reverse vaccinology approach to determine epitopes that would generate adaptive immune reactions. The resulting T and B lymphocytes epitopes were screened by various immunoinformatic tools and a peptide vaccine construct was designed. It was validated by proceeding to docking and MD simulation studies. The following design was then back-translated in nucleotide sequence and codons were optimized according to the expression host system (H. sapiens). Various sequences, including 3′ and 5′ UTR regions, Kozak sequence, poly (A) tail, etc., were introduced into the sequence for the construction of the final mRNA vaccine construct. The secondary structure was generated for validation of the mRNA vaccine construct sequence. Additionally, in silico cloning was also performed to design a vector for proceeding towards in vitro experimentation. The proposed designed vaccine construct may proceed with experimental testing for further efficacy verification and the final development of a vaccine against chikungunya virus infection.
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15
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BauA and Omp34 surface loops trigger protective antibodies against Acinetobacter baumannii in a murine sepsis model. Int Immunopharmacol 2022; 108:108731. [DOI: 10.1016/j.intimp.2022.108731] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/16/2022] [Accepted: 03/22/2022] [Indexed: 12/13/2022]
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16
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Nishimura B, Escalante J, Tuttobene MR, Subils T, Mezcord V, Pimentel C, Georgeos N, Pasteran F, Rodriguez C, Sieira R, Actis LA, Tolmasky ME, Bonomo RA, Ramirez MS. Acinetobacter baumannii response to cefiderocol challenge in human urine. Sci Rep 2022; 12:8763. [PMID: 35610334 PMCID: PMC9128776 DOI: 10.1038/s41598-022-12829-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/17/2022] [Indexed: 11/10/2022] Open
Abstract
Cefiderocol (CFDC) is a novel chlorocatechol-substituted siderophore antibiotic approved to treat complicated urinary tract infections (cUTI) and hospital-acquired and ventilator-acquired pneumonia (HAP/VAP). Previous work determined that albumin-rich human fluids increase the minimum inhibitory concentration (MICs) of Acinetobacter baumannii against CFDC and reduce the expression of genes related to iron uptake systems. This latter effect may contribute to the need for higher concentrations of CFDC to inhibit growth. The presence of human urine (HU), which contains low albumin concentrations, did not modify MIC values of two carbapenem-resistant A. baumannii. Levels of resistance to CFDC were not modified by HU in strain AMA40 but were reduced in strain AB5075. Expanding the studies to other carbapenem-resistant A. baumannii isolates showed that the presence of HU resulted in unmodified or reduced MIC of CDFC values. The expression of piuA, pirA, bauA, and bfnH determined by qRT-PCR was enhanced in A. baumannii AMA40 and AB5075 by the presence of HU in the culture medium. All four tested genes code for functions related to recognition and transport of ferric-siderophore complexes. The effect of HU on expression of pbp1, pbp3, blaOXA-51-like, blaADC, and blaNDM-1, genes associated with resistance to β-lactams, as well as genes coding for efflux pumps and porins was variable, showing dependence with the strain analyzed. We conclude that the lack of significant concentrations of albumin and free iron in HU makes this fluid behave differently from others we tested. Unlike other albumin rich fluids, the presence of HU does not impact the antibacterial activity of CFDC when tested against A. baumannii.
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Affiliation(s)
- Brent Nishimura
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, 92831, USA
| | - Jenny Escalante
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, 92831, USA
| | - Marisel R Tuttobene
- Área Biología Molecular, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina
| | - Tomás Subils
- Instituto de Procesos Biotecnológicos y Químicos de Rosario (IPROBYQ, CONICET-UNR), Rosario, Argentina
| | - Vyanka Mezcord
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, 92831, USA
| | - Camila Pimentel
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, 92831, USA
| | - Nardin Georgeos
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, 92831, USA
| | - Fernando Pasteran
- National Regional Reference Laboratory for Antimicrobial Resistance (NRL), Servicio Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas, ANLIS Dr. Carlos G. Malbrán, Buenos Aires, Argentina
| | - Cecilia Rodriguez
- Centro de Referencia Para Lactobacilos (CERELA), CONICET, Tucumán, Argentina
| | | | - Luis A Actis
- Department of Microbiology, Miami University, Oxford, USA
| | - Marcelo E Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, 92831, USA
| | - Robert A Bonomo
- Research Service and GRECC, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH, USA
- Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Biochemistry, Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH, USA
| | - María Soledad Ramirez
- Center for Applied Biotechnology Studies, Department of Biological Science, College of Natural Sciences and Mathematics, California State University Fullerton, 800 N State College Blvd, Fullerton, CA, 92831, USA.
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17
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Outer Membrane Vesicles of Acinetobacter baumannii DS002 Are Selectively Enriched with TonB-Dependent Transporters and Play a Key Role in Iron Acquisition. Microbiol Spectr 2022; 10:e0029322. [PMID: 35266817 PMCID: PMC9045253 DOI: 10.1128/spectrum.00293-22] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Outer membrane vesicles (OMVs) of Acinetobacter baumannii DS002 carry proteins which perform selective biological functions. The proteins involved in cell wall/membrane biogenesis and inorganic ion transport and metabolism occupied a significant portion of the 302 proteins associated with OMVs. Interestingly, the TonB-dependent transporters (TonRs), linked to the active transport of nutrients across the energy-deprived outer membrane, are predominant among proteins involved in inorganic ion transport and metabolism. The OMVs of DS002 contain TonRs capable of transporting iron complexed to catecholate, hydroximate, and mixed types of siderophores. Consistent with this observation, the OMVs were firmly bound to ferric-enterobactin (55Fe-Ent) and successfully transported iron into A. baumannii DS002 cells grown under iron-limiting conditions. In addition to the TonRs, OMVs also carry proteins known to promote pathogenesis, immune evasion, and biofilm formation. Our findings provide conclusive evidence for the role of OMVs in the transport of nutrients such as iron and show the presence of proteins with proven roles in pathogenicity and immune response. IMPORTANCE TonB-dependent transporters (TonRs) play a crucial role in transporting nutrients such as iron, nickel, copper, and complex carbohydrates across the energy-deprived outer membrane. Due to their unique structural features, TonRs capture nutrients in an energy-independent manner and transport them across the outer membrane by harvesting energy derived from the inner membrane-localized Ton-complex. In this study, we report the presence of TonRs capable of transporting various nutrients in OMVs and demonstrate their role in capturing and transporting ferric iron complexed with enterobactin into A. baumannii DS002 cells. The OMV-associated TonRs appear to play a critical role in the survival of A. baumannii, listed as a priority pathogen, under nutrient-deprived conditions.
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18
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Ma C, McClean S. Mapping Global Prevalence of Acinetobacter baumannii and Recent Vaccine Development to Tackle It. Vaccines (Basel) 2021; 9:vaccines9060570. [PMID: 34205838 PMCID: PMC8226933 DOI: 10.3390/vaccines9060570] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/16/2021] [Accepted: 05/22/2021] [Indexed: 12/23/2022] Open
Abstract
Acinetobacter baumannii is a leading cause of nosocomial infections that severely threaten public health. The formidable adaptability and resistance of this opportunistic pathogen have hampered the development of antimicrobial therapies which consequently leads to very limited treatment options. We mapped the global prevalence of multidrug-resistant A. baumannii and showed that carbapenem-resistant A. baumannii is widespread throughout Asia and the Americas. Moreover, when antimicrobial resistance rates of Acinetobacter spp. exceed a threshold level, the proportion of A. baumannii isolates from clinical samples surges. Therefore, vaccines represent a realistic alternative strategy to tackle this pathogen. Research into anti-A. baumannii vaccines have enhanced in the past decade and multiple antigens have been investigated preclinically with varying results. This review summarises the current knowledge of virulence factors relating to A. baumannii–host interactions and its implication in vaccine design, with a view to understanding the current state of A. baumannii vaccine development and the direction of future efforts.
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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: 20] [Impact Index Per Article: 6.7] [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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A Comprehensive Study of the Relationship between the Production of β-Lactamase Enzymes and Iron/Siderophore Uptake Regulatory Genes in Clinical Isolates of Acinetobacter baumannii. Int J Microbiol 2021; 2021:5565537. [PMID: 33815505 PMCID: PMC7990553 DOI: 10.1155/2021/5565537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 02/25/2021] [Accepted: 03/12/2021] [Indexed: 11/28/2022] Open
Abstract
Background The iron/siderophore uptake system (IUS) involved in the Acinetobacter baumannii pathogenicity. However, IUS's role in antibiotic resistance and the production of β-lactamase enzymes of A. baumannii are unclear. This study aimed to investigate the relationship between the production of β-lactamase enzymes and IUS regulatory genes in clinical isolates of A. baumannii. Methods. A. baumannii isolates were collected from clinical isolates using biochemical tests. The antibiotic resistance patterns and β-lactamase-producing strains were identified using the disk diffusion method (DDM). Also, IUS genes were detected by the polymerase chain reaction (PCR) method. Results Seventy-two (72) A. baumannii isolates were collected from a different clinical specimen. Gentamicin-resistant strains (43%) had the highest frequency, and aztreonam-resistant strains (12.5%) had the lowest frequency. Also, the distribution of AmpC and MBL producing isolates were 27.7% and 35%, respectively. Moreover, the frequencies of basD, bauA, pld, paaE, entA, feoB, hemO, and tonB genes were as follows: 12.5%, 15.2%, 11.1%, 15.2%, 19.4%, 16.6%, 23.6%, and 6.9%. Further, a strong correlation was observed between the abundance of β-lactamase-producing strains and IUS genes. Conclusions Based on our knowledge from this study, the association between β-lactamase production and IUS genes in A. baumannii plays an essential role in the emergence of drug-resistant strains.
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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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Ramezanalizadeh F, Rasooli I, Owlia P. Protective response against Acinetobacter baumannii with ferric iron receptors HemTR-BauA in a murine sepsis model. Future Microbiol 2021; 16:143-157. [PMID: 33528272 DOI: 10.2217/fmb-2020-0133] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Aim: Iron uptake and metabolism pathways are promising targets in vaccine development as an alternative strategy for antibiotics. Methods & methods: HemTR, a putative heme receptor of Acinetobacter baumannii, was expressed and its protectivity against A. baumannii was determined singly or in combination with the siderophore receptor, BauA, in mice. Results: High level of IgG was elicited. There was a delay in mice mortality with reduced bacterial loads in internal organs in the sublethal challenge. Protection was better in the HemTR-BauA group in both lethal and sublethal challenges. Passive transfer of anti-HemTR and anti-BauA partially protected mice against A. baumannii infection. Conclusion: HemTR in combination with other iron receptors could contribute to the development of protective vaccines against A. baumannii.
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Affiliation(s)
| | - Iraj Rasooli
- Department of Biology, Molecular Microbiology Research Center, Shahed University, Tehran, 3319118651, Iran
| | - Parviz Owlia
- Department of Microbiology, Molecular Microbiology Research Center, School of Medicine, Shahed University, Tehran, 3319118651, Iran
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Wang J, Xiong K, Pan Q, He W, Cong Y. Application of TonB-Dependent Transporters in Vaccine Development of Gram-Negative Bacteria. Front Cell Infect Microbiol 2021; 10:589115. [PMID: 33585268 PMCID: PMC7873555 DOI: 10.3389/fcimb.2020.589115] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 12/11/2020] [Indexed: 12/28/2022] Open
Abstract
Multiple scarce nutrients, such as iron and nickel, are essential for bacterial growth. Gram-negative bacteria secrete chelators to bind these nutrients from the environment competitively. The transport of the resulting complexes into bacterial cells is mediated by TonB-dependent transporters (TBDTs) located at the outer membrane in Gram-negative bacteria. The characteristics of TBDTs, including surface exposure, protective immunogenicity, wide distribution, inducible expression in vivo, and essential roles in pathogenicity, make them excellent candidates for vaccine development. The possible application of a large number of TBDTs in immune control of the corresponding pathogens has been recently investigated. This paper summarizes the latest progresses and current major issues in the application.
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Affiliation(s)
- Jia Wang
- Department of Clinical Laboratory, Traditional Medicine Hospital Affiliated to Southwest Medical University, Luzhou, China
| | - Kun Xiong
- Department of Cold Environmental Medicine, Institute of High Altitude Military Medicine, Army Medical University, Chongqiong, China
| | - Qu Pan
- Department of Microbiology, Chengdu Medical College, Chengdu, China
| | - Weifeng He
- Department of Burn, Southwest Hospital, Army Medical University, Chongqing, China
| | - Yanguang Cong
- Department of Clinical Laboratory, Traditional Medicine Hospital Affiliated to Southwest Medical University, Luzhou, China.,Precision Medicine Center, Traditional Medicine Hospital Affiliated to Southwest Medical University, Luzhou, China
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Sheldon JR, Skaar EP. Acinetobacter baumannii can use multiple siderophores for iron acquisition, but only acinetobactin is required for virulence. PLoS Pathog 2020; 16:e1008995. [PMID: 33075115 PMCID: PMC7595644 DOI: 10.1371/journal.ppat.1008995] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 10/29/2020] [Accepted: 09/18/2020] [Indexed: 12/22/2022] Open
Abstract
Acinetobacter baumannii is an emerging pathogen that poses a global health threat due to a lack of therapeutic options for treating drug-resistant strains. In addition to acquiring resistance to last-resort antibiotics, the success of A. baumannii is partially due to its ability to effectively compete with the host for essential metals. Iron is fundamental in shaping host-pathogen interactions, where the host restricts availability of this nutrient in an effort to curtail bacterial proliferation. To circumvent restriction, pathogens possess numerous mechanisms to obtain iron, including through the use of iron-scavenging siderophores. A. baumannii elaborates up to ten distinct siderophores, encoded from three different loci: acinetobactin and pre-acinetobactin (collectively, acinetobactin), baumannoferrins A and B, and fimsbactins A-F. The expression of multiple siderophores is common amongst bacterial pathogens and often linked to virulence, yet the collective contribution of these siderophores to A. baumannii survival and pathogenesis has not been investigated. Here we begin dissecting functional redundancy in the siderophore-based iron acquisition pathways of A. baumannii. Excess iron inhibits overall siderophore production by the bacterium, and the siderophore-associated loci are uniformly upregulated during iron restriction in vitro and in vivo. Further, disrupting all of the siderophore biosynthetic pathways is necessary to drastically reduce total siderophore production by A. baumannii, together suggesting a high degree of functional redundancy between the metabolites. By contrast, inactivation of acinetobactin biosynthesis alone impairs growth on human serum, transferrin, and lactoferrin, and severely attenuates survival of A. baumannii in a murine bacteremia model. These results suggest that whilst A. baumannii synthesizes multiple iron chelators, acinetobactin is critical to supporting growth of the pathogen on host iron sources. Given the acinetobactin locus is highly conserved and required for virulence of A. baumannii, designing therapeutics targeting the biosynthesis and/or transport of this siderophore may represent an effective means of combating this pathogen.
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Affiliation(s)
- Jessica R. Sheldon
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
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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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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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