Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Generation of Synthetic Acinetobacter baumannii-Specific Nanobodies.

ABSTRACT: The bacterial pathogen Acinetobacter baumannii is a leading cause of drug-resistant infections. Here, we investigated the potential of developing nanobodies that can recognize A. baumannii over other Gram-negative bacteria. Through generation and panning of a synthetic nanobody library, we identified several potential lead candidates. We demonstrate how incorporation of next-generation sequencing analysis can aid in the selection of lead candidate nanobodies. Using monoclonal phage display, we validated the binding of lead nanobodies to A. baumannii. Subsequent purification and biochemical characterization revealed one particularly robust nanobody that specifically bound select A. baumannii strains compared to other common drug-resistant pathogens. These findings support the potential for nanobodies to selectively target A. baumannii and the identification of lead candidates for future investigation.

SUBMITTER: Knauf GA

PROVIDER: S-EPMC10262196 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Generation of Synthetic Acinetobacter baumannii-Specific Nanobodies.

Knauf Gregory A GA Groover Kyra E KE O'Donnell Angela C AC Davies Bryan W BW

ACS infectious diseases 20230510 6

The bacterial pathogen Acinetobacter baumannii is a leading cause of drug-resistant infections. Here, we investigated the potential of developing nanobodies that can recognize A. baumannii over other Gram-negative bacteria. Through generation and panning of a synthetic nanobody library, we identified several potential lead candidates. We demonstrate how incorporation of next-generation sequencing analysis can aid in the selection of lead candidate nanobodies. Using monoclonal phage ...[more]

PMID: 37162304

Similar Datasets

Generation of synthetic Acinetobacter baumannii specific nanobodies

Project description:The bacterial pathogen, Acinetobacter baumannii, is a leading cause of drug-resistant infections. Here, we investigated the potential of developing nanobodies that specifically recognize A. baumannii over other Gram-negative bacteria. Through generation and panning of a synthetic nanobody library, we identified several potential lead candidates. We demonstrate how incorporation of next generation sequencing analysis can aid in selection of lead candidates for further characterization. Using monoclonal phage display, we validated the binding of several lead nanobodies to A. baumannii. Subsequent purification and biochemical characterization revealed one particularly robust nanobody that broadly and specifically bound A. baumannii compared to other common drug resistant pathogens. These findings support the potentially for nanobodies to selectively target A. baumannii and the identification of lead candidates for possible future diagnostic and therapeutic development.

2023-06-21 | GSE202972 | GEO

Generation of synthetic Acinetobacter baumannii specific nanobodies

Project description:Generation of synthetic Acinetobacter baumannii specific nanobodies

| PRJNA837907 | ENA

Semi-Synthetic Glycoconjugate Vaccine Lead Against Acinetobacter baumannii 17978.

Project description:Acinetobacter baumannii is a opportunistic bacterial pathogen responsible for serious nosocomial infections that is becoming increasingly resistant against antibiotics. Capsular polysaccharides (CPS) that cover A. baumannii are a major virulence factor that play an important role in pathogenesis, are used to assign serotypes and provide the basis for vaccine development. Synthetic oligosaccharides resembling the CPS of A. baumannii 17978 were printed onto microarray slides and used to screen sera from patients infected with A. baumannii as well as a monoclonal mouse antibody (mAb C8). A synthetic oligosaccharide emerged from glycan array screening as lead for the development of a vaccine against A. baumannii 17978. Tetrasaccharide 20 is a key epitope for recognition by an antibody and is a vaccine lead.

| S-EPMC9826233 | biostudies-literature

AbAMPdb: a database of Acinetobacter baumannii specific antimicrobial peptides.

Project description:Acinetobacter baumannii has emerged as a prominent nosocomial pathogen, exhibiting a progressive rise in resistance to therapeutic interventions. This rise in resistance calls for alternative strategies. Here, we propose an alternative yet specialized resource on antimicrobial peptides (AMPs) against A. baumannii. Database 'AbAMPdb' is the manually curated collection of 300 entries containing the 250 experimental AMP sequences and 50 corresponding synthetic or mutated AMP sequences. The mutated sequences were modified with reported amino acid substitutions intended for decreasing the toxicity and increasing the antimicrobial potency. AbAMPdb also provides 3D models of all 300 AMPs, comprising 250 natural and 50 synthetic or mutated AMPs. Moreover, the database offers docked complexes comprising 5000 AMPs and their corresponding A. baumannii target proteins. These complexes, accessible in Protein Data Bank format, enable the 2D visualization of the interacting amino acid residues. We are confident that this comprehensive resource furnishes vital information concerning AMPs, encompassing their docking interactions with virulence factors and antibiotic resistance proteins of A. baumannii. To enhance clinical relevance, the characterized AMPs could undergo further investigation both in vitro and in vivo. Database URL: https://abampdb.mgbio.tech/.

| S-EPMC11470754 | biostudies-literature

First Characterization of Acinetobacter baumannii-Specific Filamentous Phages.

Project description:Filamentous bacteriophages belonging to the order Tubulavirales, family Inoviridae, significantly affect the properties of Gram-negative bacteria, but filamentous phages of many important pathogens have not been described so far. The aim of this study was to examine A. baumannii filamentous phages for the first time and to determine their effect on bacterial virulence. The filamentous phages were detected in 15.3% of A. baumannii strains as individual prophages in the genome or as tandem repeats, and a slightly higher percentage was detected in the culture collection (23.8%). The phylogenetic analyses revealed 12 new genera within the Inoviridae family. Bacteriophages that were selected and isolated showed structural and genomic characteristics of the family and were unable to form plaques. Upon host infection, these phages did not significantly affect bacterial twitching motility and capsule production but significantly affected growth kinetics, reduced biofilm formation, and increased antibiotic sensitivity. One of the possible mechanisms of reduced resistance to antibiotics is the observed decreased expression of efflux pumps after infection with filamentous phages.

| S-EPMC11209303 | biostudies-literature

Strain Specific Variations in Acinetobacter baumannii Complement Sensitivity.

Project description:The complement system is required for innate immunity against Acinetobacter baumannii, an important cause of antibiotic resistant systemic infections. A. baumannii strains differ in their susceptibility to the membrane attack complex (MAC) formed from terminal complement pathway proteins, but the reasons for this variation remain poorly understood. We have characterized in detail the complement sensitivity phenotypes of nine A. baumannii clinical strains and some of the factors that might influence differences between strains. Using A. baumannii laboratory strains and flow cytometry assays, we first reconfirmed that both opsonization with the complement proteins C3b/iC3b and MAC formation were inhibited by the capsule. There were marked differences in C3b/iC3b and MAC binding between the nine clinical A. baumannii strains, but this variation was partially independent of capsule composition or size. Opsonization with C3b/iC3b improved neutrophil phagocytosis of most strains. Importantly, although C3b/iC3b binding and MAC formation on the bacterial surface correlated closely, MAC formation did not correlate with variations between A. baumannii strains in their levels of serum resistance. Genomic analysis identified only limited differences between strains in the distribution of genes required for serum resistance, but RNAseq data identified three complement-resistance genes that were differentially regulated between a MAC resistant and two MAC intermediate resistant strains when cultured in serum. These data demonstrate that clinical A. baumannii strains vary in their sensitivity to different aspects of the complement system, and that the serum resistance phenotype was influenced by factors in addition to the amount of MAC forming on the bacterial surface.

| S-EPMC9258041 | biostudies-literature

An Optimized Synthetic-Bioinformatic Natural Product Antibiotic Sterilizes Multidrug-Resistant Acinetobacter baumannii-Infected Wounds.

Project description:The antibiotic paenimucillin A was originally identified using a culture-independent synthetic-bioinformatic natural product (syn-BNP) discovery approach. Here we report on a bioinformatics-guided survey of paenimucillin A analogs that led to the discovery of paenimucillin C. Paenimucillin C inhibits the growth of multidrug-resistant (MDR) Acinetobacter baumannii clinical isolates, as well as other Gram-negative bacterial pathogens. In a rat cutaneous wound model, it completely sterilized MDR A. baumannii wound infections with no sign of rebound. Mechanistic studies point to a membrane-associated mode of action that results in leakage of intracellular contents. IMPORTANCE Natural product-inspired antibiotics have saved millions of lives and played a critical role in modern medicine. However, the emergence of drug-resistant pathogens is outpacing the rate at which new clinically useful antibiotics are being discovered. The lack of a means to combat infections caused by multidrug-resistant (MDR) Acinetobacter baumannii is of particular concern. The sharp increase in cases of MDR A. baumannii infections in recent years prompted the CDC (https://www.cdc.gov/drugresistance/biggest_threats.html) and WHO (http://www.who.int/medicines/publications/global-priority-list-antibiotic-resistant-bacteria/en/) to list this pathogen as a "serious threat" and "critical pathogen," respectively. Here we report a new antibiotic, paenimucillin C, active against Gram-negative bacterial pathogens, including many clinical isolates of MDR A. baumannii strains. Mechanistic studies point to membrane disruption leading to leakage of intracellular contents as its antibacterial mode of action. Paenimucillin C sterilizes MDR A. baumannii infections in a rat cutaneous wound model with no sign of rebound infection, providing a potential new therapeutic regimen.

| S-EPMC5784245 | biostudies-literature

Synthetic Pseudaminic-Acid-Based Antibacterial Vaccine Confers Effective Protection against Acinetobacter baumannii Infection.

Project description:Acinetobacter baumannii exhibits resistance to most first-line antibiotics; thus, development of new antibacterial agents is urgently required. Pseudaminic acid exists as the surface glycan of A. baumannii. In this study, we chemically synthesized pseudaminic acid, conjugated it to carrier protein CRM197 using the OPA (ortho-phthalaldehyde) chemistry, and obtained three Pse-CRM197 conjugates with different Pse loadings. These Pse-CRM197 conjugates were found to stimulate high immune responses in mice, which protected the vaccinated mice from infections caused by Pse-producing A. baumannii. Our data indicate that chemically synthesized Pse-CRM197 conjugates can be developed into vaccines against Pse-bearing pathogens, thus offering a feasible alternative for the control of clinical infections caused by multidrug-resistant (MDR) A. baumannii, for which current treatment options are extremely limited.

| S-EPMC8461771 | biostudies-literature

Characterizing Acinetobacter baumannii desiccation tolerance.

Project description:Desiccation tolerance has been implicated as an important characteristic that potentiates the spread of the bacterial pathogen Acinetobacter baumannii through hospitals on dry surfaces. Despite the potential importance of this stress response, scarce information is available describing the underlying mechanisms of A. baumannii desiccation tolerance. Here we characterize the factors influencing desiccation survival of A. baumannii. At the macroscale level, we find that desiccation tolerance is influenced by cell density, growth phase, and desiccation medium. Our transcriptome analysis indicates that desiccation represents a unique state for A. baumannii compared to commonly studied growth conditions and strongly influences pathways responsible for proteostasis. Remarkably, we find that an increase in total cellular protein aggregates, which is often considered deleterious, correlates positively with the ability of A. baumannii to survive desiccation. We show that artificially inducing protein aggregate formation increases desiccation survival, and more importantly, that proteins incorporated into cellular aggregates can retain activity. Our results suggest that protein aggregates may promote desiccation tolerance in A. baumannii through preserving and protecting proteins from damage during desiccation until rehydration occurs.

2018-10-27 | GSE111383 | GEO

Biological Properties of 12 Newly Isolated Acinetobacter baumannii-Specific Bacteriophages.

Project description:Infections with the opportunistic Gram-negative bacterium Acinetobacter baumannii pose a serious threat today, which is aggravated by the growing problem of multi-drug resistance among bacteria, caused by the overuse of antibiotics. Treatment of infections caused by antibiotic-resistant A. baumannii strains with the use of phage therapy is not only a promising alternative, but sometimes the only option. Therefore, phages specific for clinical multi-drug resistant A. baumannii were searched for in environmental, municipal, and hospital wastewater samples collected from different locations in Poland. The conducted research allowed us to determine the biological properties and morphology of the tested phages. As a result of our research, 12 phages specific for A. baumannii, 11 of which turned out to be temperate and only one lytic, were isolated. Their lytic spectra ranged from 11 to 75%. The plaques formed by most phages were small and transparent, while one of them formed relatively large plaques with a clearly marked 'halo' effect. Based on Transmission Electron Microscopy (TEM), most of our phages have been classified as siphoviruses (only one phage was classified as a podovirus). All phages have icosahedral capsid symmetry, and 11 of them have a long tail. Optimal multiplicity of infections (MOIs) and the adsorption rate were also determined. MOI values varied depending on the phage-from 0.001 to 10. Based on similarities to known bacteriophages, our A. baumannii-specific phages have been proposed to belong to the Beijerinckvirinae and Junivirinae subfamilies. This study provides an additional tool in the fight against this important pathogen and may boost the interest in phage therapy as an alternative and supplement to the current antibiotics.

| S-EPMC9866556 | biostudies-literature