Dataset Information

A dual-function microcin in Acinetobacter baumannii facilitates biofilm formation and interbacterial competition

ABSTRACT: Acinetobacter baumannii is a frequent cause of drug-resistant nosocomial infections. Its ability to persist in harsh environments facilities its spread and is supported by formation of robust biofilms. Biofilms are comprised of communities of bacteria encased in a matrix of exopolymeric substances. Microcins are small (<10kDa) secreted antimicrobial proteins that mediate bacterial competition but have not been associated with biofilms directly. Here we describe the first dual action microcin from A. baumannii that has both antibacterial activity and is required for biofilm formation. We show the ability of this microcin to support biofilm formation is independent of its antibacterial action, and how this microcin forms amyloid fibers in secreted and purified forms, a function that is critical to biofilm formation. Scanning electron microscopy (SEM) shows this microcin surrounding A. baumannii in fibers suggesting it may act as support for polymetric biofilm components. Finally we map the molecular pathway used by this microcin to inhibit prey cells, which uncovers a new host protein that facilities microcin mediated-membrane disruption. This study reports the first instance of a multifunctional microcin, which uncovers new roles for this understudied class of antibacterial proteins.

ORGANISM(S): Acinetobacter baumannii

PROVIDER: GSE288718 | GEO | 2026/02/10

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Is there a universal genetically programmed defense providing tolerance to antibiotics when bacteria grow as biofilms? A comparison between biofilms of three different bacterial species by transcriptomic and metabolomic approaches uncovered no evidence of one. Single-species biofilms of three bacterial species (Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter baumannii) were grown in vitro for three days then challenged with respective antibiotics (ciprofloxacin, daptomycin, tigecycline) for an additional 24 h. All three microorganisms displayed reduced susceptibility in biofilms compared to planktonic cultures. Global transcriptomic profiling of gene expression comparing biofilm to planktonic and antibiotic-treated biofilm to untreated biofilm was performed. Extracellular metabolites including 18 amino acids, glucose, lactate, acetate, formate, and ethanol were measured to characterize the utilization of carbon sources between biofilms, treated biofilms, and planktonic cells. While all three bacteria exhibited a species-specific signature of stationary phase, no conserved gene, gene set, or common functional pathway could be identified that changed consistently across the three microorganisms. Across the three species, glucose consumption was increased in biofilms compared to planktonic cells and alanine and aspartic acid utilization were decreased in biofilms compared to planktonic cells. The reasons for these changes were not readily apparent in the transcriptomes. No common shift in the utilization pattern of carbon sources was discerned when comparing untreated to antibiotic-exposed biofilms. Overall, our measurements do not support the existence of a common genetic or biochemical basis for biofilm tolerance against antibiotics. Rather, there are likely myriad genes, proteins, and metabolic pathways that influence the physiological state of microorganisms in biofilms contributing to antibiotic tolerance. The Acinetobacter baumannii microarray data from the study described above is deposited here.

Dataset Information

A dual-function microcin in Acinetobacter baumannii facilitates biofilm formation and interbacterial competition

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets