Microevolution in the major outer membrane protein OmpA of Acinetobacter baumannii

Viale, Andrea; Evans, Benjamin A.

doi:10.1099/mgen.0.000381

Cited by 24 publications

(15 citation statements)

References 68 publications

(158 reference statements)

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“…However, the increase in antibiotic-susceptibility of these mutants could be related to a broader membrane permeability as a consequence of membrane alterations [ 61 ]. Nevertheless, several studies demonstrated that OmpA acts as a specific and selective channel for small antibiotics [ 41 , 61 , 62 , 124 ]. However, multiple data indicate that OmpA is associated with efflux pump systems located in the inner membrane to counteract the influx of antibiotics [ 62 ].…”

Section: A Baumannii and The Treasure Of Its Virulomementioning

confidence: 99%

“…Due to its key role, several proteins control ompA expression such as the global repressor H-NS and an anti-repressor (i.e., gene locus A1S_0316), the RNA chaperone Hfq as well as the two-component system BfmSR [ 41 , 125 , 126 ]. Its high amino acid conservation among isolates, crucial structural role and strong immunogenicity make OmpA the ideal target for the development of an A. baumannii vaccine [ 124 ]. Additionally, several studies have addressed the role of CarO or carbapenem susceptibility porin in A. baumannii [ 13 , 41 , 68 , 69 , 70 ].…”

Section: A Baumannii and The Treasure Of Its Virulomementioning

confidence: 99%

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Acinetobacter baumannii: An Ancient Commensal with Weapons of a Pathogen

et al. 2021

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Acinetobacter baumannii is regarded as a life-threatening pathogen associated with community-acquired and nosocomial infections, mainly pneumonia. The rise in the number of A. baumannii antibiotic-resistant strains reduces effective therapies and increases mortality. Bacterial comparative genomic studies have unraveled the innate and acquired virulence factors of A. baumannii. These virulence factors are involved in antibiotic resistance, environmental persistence, host-pathogen interactions, and immune evasion. Studies on host–pathogen interactions revealed that A. baumannii evolved different mechanisms to adhere to in order to invade host respiratory cells as well as evade the host immune system. In this review, we discuss current data on A. baumannii genetic features and virulence factors. An emphasis is given to the players in host–pathogen interaction in the respiratory tract. In addition, we report recent investigations into host defense systems using in vitro and in vivo models, providing new insights into the innate immune response to A. baumannii infections. Increasing our knowledge of A. baumannii pathogenesis may help the development of novel therapeutic strategies based on anti-adhesive, anti-virulence, and anti-cell to cell signaling pathways drugs.

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Section: A Baumannii and The Treasure Of Its Virulomementioning

confidence: 99%

Section: A Baumannii and The Treasure Of Its Virulomementioning

confidence: 99%

Acinetobacter baumannii: An Ancient Commensal with Weapons of a Pathogen

et al. 2021

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“…The annotated protein referred to as WP_166170865 consists of three distinct domains, including an N-terminal signal peptide, a β-barrel, and an OmpA-like domain at the C terminus. The β-barrel domain of SA01-OmpA, like its homologs in other Acinetobacter ( 31 ), consists of eight β-strands connected with four periplasmic inner loops and four outer membrane loops ( Fig. 2a ).…”

Section: Resultsmentioning

confidence: 99%

“…The genomic diversity among Acinetobacter strains and their adaptive evolution can cause physiological variations among them ( 30 ). Moreover, there are different variants of OmpA (with potentially different physicochemical properties) in the Acinetobacter population, which might be due to the lateral gene transfer ( 31 ). Therefore, the entire genome of Acinetobacter sp.…”

Section: Introductionmentioning

confidence: 99%

New Provisional Function of OmpA from Acinetobacter sp. Strain SA01 Based on Environmental Challenges

et al. 2021

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An outer membrane protein A (OmpA) from Acinetobacter sp. strain SA01 was identified and characterized in-depth based on the structural and functional characteristics already known of its homologues. In silico structural studies showed that this protein can be a slow porin, binds to peptidoglycan, and exhibits emulsifying properties. Characterization of the recombinant SA01-OmpA, based on its emulsifying properties, represented its promising potentials in biotechnology. Also, the presence of SA01-OmpA in outer membrane vesicles (OMV) and biofilm showed that this protein, like its homologues in Acinetobacter baumannii, can be secreted into the extracellular environment through OMVs and play a role in the formation of biofilm. After ensuring the correct selection of the protein of interest, the role of oxidative stress induced by cell nutritional parameters (utilization of specific carbon sources) on the expression level of OmpA was carefully studied. For this purpose, the oxidative stress level of SA01 cell cultures in the presence of three nonrelevant carbon sources (sodium acetate, ethanol, and phenol) was examined under each condition. High expression of SA01-OmpA in ethanol- and phenol-fed cells with higher levels of oxidative stress than acetate suggested that oxidative stress could be a substantial factor in the regulation of SA01-OmpA expression. The significant association of SA01-OmpA expression with the levels of oxidative stress induced by cadmium and H2O2, with oxidative stress-inducing properties and lack of nutritional value, confirmed that the cells tend to harness their capacities with a possible increase in OmpA production. Collectively, this study suggests a homeostasis role for OmpA in Acinetobacter sp. SA01 under oxidative stress besides assuming many other roles hitherto attributed to this protein. IMPORTANCE Acinetobacter OmpA is known as a multifaceted protein with multiple functions, including emulsifying properties. Bioemulsifiers are surface-active compounds that can disperse hydrophobic compounds in water and help increase the bioavailability of hydrophobic hydrocarbons to be used by degrading microorganisms. In this study, an OmpA from Acinetobacter sp. SA01 was identified and introduced as an emulsifier with a higher emulsifying capacity than Pseudomonas aeruginosa rhamnolipid. We also showed that the expression of this protein is not dependent on the nutritional requirements but is more influenced by the oxidative stress caused by stressors. This finding, along with the structural role of this protein as a slow porin or its role in OMV biogenesis and biofilm formation, suggests that this protein can play an important role in maintaining cellular homeostasis under oxidative stress conditions. Altogether, the present study provides a new perspective on the functional performance of Acinetobacter OmpA, which can be used both to optimize its production as an emulsifier and a target in the treatment of multidrug-resistant strains.

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“… 68 , 69 , 70 , 71 Polymorphism of OmpA that resulted in five major bacterium variants, however, may limit the effectiveness of vaccine from a single OmpA variant. 72 In addition to OmpA, other OMPs that have been evaluated for their potential as vaccine candidates are Omp22 73 and BamA. 74 These target proteins have been demonstrated as highly conserved among the A. baumannii strains (95–99%) and displayed promising potential for active and passive immunization.…”

Section: Progress In a Baumannii Vaccine Developmentmentioning

confidence: 99%

Facing the challenges of multidrug-resistant Acinetobacter baumannii : progress and prospects in the vaccine development

MatRahim

Lee

Strych

et al. 2021

Human Vaccines & Immunotherapeutics

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In 2017, the World Health Organization (WHO) named A. baumannii as one of the three antibiotic-resistant bacterial species on its list of global priority pathogens in dire need of novel and effective treatment. With only polymyxin and tigecycline antibiotics left as last-resort treatments, the need for novel alternative approaches to the control of this bacterium becomes imperative. Vaccines against numerous bacteria have had impressive records in reducing the burden of the respective diseases and addressing antimicrobial resistance; as in the case of Haemophilus influenzae type b . A similar approach could be appropriate for A. baumannii. Toward this end, several potentially protective antigens against A. baumannii were identified and evaluated as vaccine antigen candidates. A licensed vaccine for the bacteria, however, is still not in sight. Here we explore and discuss challenges in vaccine development against A. baumannii and the promising approaches for improving the vaccine development process.

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Microevolution in the major outer membrane protein OmpA of Acinetobacter baumannii

Abstract: Acinetobacter baumannii is nowadays a relevant nosocomial pathogen characterized by multidrug resistance (MDR) and concomitant difficulties to treat in… Show more

Cited by 24 publications

References 68 publications

Acinetobacter baumannii: An Ancient Commensal with Weapons of a Pathogen

Acinetobacter baumannii: An Ancient Commensal with Weapons of a Pathogen

New Provisional Function of OmpA from Acinetobacter sp. Strain SA01 Based on Environmental Challenges

Facing the challenges of multidrug-resistant Acinetobacter baumannii : progress and prospects in the vaccine development

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