Related Experiment Video

Updated: Jun 23, 2025

Author Spotlight: Advancing Antibiotic Resistance Research Using an Efflux-Deficient Bacterial Strain and a Single-Copy Gene Expression System
05:06

Author Spotlight: Advancing Antibiotic Resistance Research Using an Efflux-Deficient Bacterial Strain and a Single-Copy Gene Expression System

Published on: January 5, 2024

581

Arginine catabolism is essential to polymyxin dependence in Acinetobacter baumannii

Mei-Ling Han1, Yasser Alsaadi1, Jinxin Zhao1

  • 1Infection Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; Centre to Impact AMR, Monash University, Clayton, VIC 3800, Australia.

Cell Reports
|June 26, 2024
PubMed

Insights

Arginine metabolism is key in polymyxin-dependent Acinetobacter baumannii. Altered arginine breakdown and supplementation impact bacterial survival and polymyxin resistance, aiding treatment strategies.

Area of Science:

  • Microbiology
  • Antibiotic Resistance
  • Biochemistry

Background:

  • Polymyxins are crucial for treating infections caused by Acinetobacter baumannii.
  • Emergence of polymyxin-resistant A. baumannii strains dependent on polymyxins poses significant clinical challenges.
  • Understanding resistance mechanisms is vital for developing effective therapies.

Purpose of the Study:

  • To investigate the role of arginine metabolism in polymyxin-dependent Acinetobacter baumannii.
  • To elucidate the molecular mechanisms underlying polymyxin dependence in A. baumannii.

Main Methods:

  • Comparative analysis of arginine metabolism pathways in polymyxin-dependent and wild-type A. baumannii strains.
  • Metabolite quantification (L-arginine, L-glutamate) and gene expression analysis (astABCDE operon).
  • Functional studies involving arginine supplementation and gene deletion (astA).
  • Outer membrane analysis (phosphatidylglycerol, phosphatidylethanolamine).

Main Results:

  • Polymyxin-dependent strains exhibit altered arginine degradation pathways with depleted metabolites and increased astABCDE operon expression.
  • Arginine supplementation restored metabolic activity and reduced polymyxin dependence.
  • Deletion of astA altered outer membrane lipid composition, reducing polymyxin interaction.

Conclusions:

  • Arginine metabolism is essential for polymyxin-dependent A. baumannii survival.
  • Targeting arginine metabolism offers a potential strategy to combat polymyxin-dependent infections.
  • This research provides insights into treating infections caused by difficult-to-detect polymyxin-dependent A. baumannii.
Keywords:
CP: MetabolismCP: Microbiology

More Related Videos

Generating Transposon Insertion Libraries in Gram-Negative Bacteria for High-Throughput Sequencing08:19

Generating Transposon Insertion Libraries in Gram-Negative Bacteria for High-Throughput Sequencing

Published on: July 7, 2020

10.3K
Cystic Fibrosis Aggregate Biofilm Model to Study Infection-relevant Gene Expression08:58

Cystic Fibrosis Aggregate Biofilm Model to Study Infection-relevant Gene Expression

Published on: April 18, 2025

441

Related Concept Videos

Phase II Reactions: Acetylation Reactions01:24

Phase II Reactions: Acetylation Reactions

Acetylation, a phase II biotransformation reaction, introduces an acetyl group to drugs or their metabolites. Acetyltransferase enzymes facilitate this reaction, which resembles α-amino acid conjugation due to the addition of a functional group to the drug molecule.
The substrates for acetylation are typically drugs or their metabolites with an amino, sulfonamide, or hydrazine functional group. Acetylation can occur at several points in the drug molecule, including primary, secondary, and...
213
GPCRs Regulate Adenylyl Cylase Activity01:09

GPCRs Regulate Adenylyl Cylase Activity

Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
5.5K
Prokaryotic Transcriptional Activators and Repressors01:58

Prokaryotic Transcriptional Activators and Repressors

The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
21.0K
Overview of Protein Metabolism01:21

Overview of Protein Metabolism

Proteins are broken down into amino acids during digestion. Unlike fats and carbohydrates, which are stored for later use, proteins are not. Instead, amino acids are either used to produce ATP through oxidation or contribute to the creation of new proteins for the growth and repair of the body. Any surplus amino acids from the diet are converted into glucose or triglycerides rather than excreted.
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
991
Cytoskeletal Proteins in Bacteria01:29

Cytoskeletal Proteins in Bacteria

Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.4K
Allosteric Proteins-ATCase01:19

Allosteric Proteins-ATCase

Binding sites linkages can regulate a protein's function.  For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to  N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
5.7K