Accession ARO:3003573
CARD Short NameLpxA
DefinitionThe LpxA gene is widely known to be involved in the biosynthesis of lipid A in Gram-negative bacteria and mutations to this gene may cause resistance to antimicrobial peptides that target the outer membrane.
AMR Gene FamilyAcinetobacter mutant Lpx gene conferring resistance to colistin
Drug Classpeptide antibiotic
Resistance Mechanismantibiotic target alteration
Classification15 ontology terms | Show
Parent Term(s)3 ontology terms | Show
+ Acinetobacter mutant Lpx gene conferring resistance to colistin [AMR Gene Family]
+ confers_resistance_to_antibiotic colistin A [Antibiotic]
+ confers_resistance_to_antibiotic colistin B [Antibiotic]

Moffatt JH, et al. 2010. Antimicrob Agents Chemother 54(12): 4971-4977. Colistin resistance in Acinetobacter baumannii is mediated by complete loss of lipopolysaccharide production. (PMID 20855724)

Beceiro A, et al. 2013. Antimicrob Agents Chemother 58(1): 518-526. Biological cost of different mechanisms of colistin resistance and their impact on virulence in Acinetobacter baumannii. (PMID 24189257)


Prevalence of LpxA among the sequenced genomes, plasmids, and whole-genome shotgun assemblies available at NCBI or IslandViewer for 413 important pathogens (see methodological details and complete list of analyzed pathogens). Values reflect percentage of genomes, plasmids, genome islands, or whole-genome shotgun assemblies that have at least one hit to the AMR detection model. Default view includes percentages calculated based on Perfect plus Strict RGI hits. Select the checkbox to view percentages based on only Perfect matches to AMR reference sequences curated in CARD (note: this excludes resistance via mutation as references in protein variant models are often wild-type, sensitive sequences).

Prevalence: protein variant model

SpeciesNCBI ChromosomeNCBI PlasmidNCBI WGSNCBI GI
No prevalence data

Detection Models

Model Type: protein variant model

Model Definition: Protein Variant Models (PVM) perform a similar search as Protein Homolog Models (PHM), i.e. detect protein sequences based on their similarity to a curated reference sequence, but secondarily screen query sequences for curated sets of mutations to differentiate them from antibiotic susceptible wild-type alleles. PVMs are designed to detect AMR acquired via mutation of house-keeping genes or antibiotic targets, e.g. a mutated gyrase resistant to aminocoumarin antibiotics. PVMs include a protein reference sequence (often from antibiotic susceptible wild-type alleles), a curated bit-score cut-off, and mapped resistance variants. Mapped resistance variants may include any or all of single point mutations, insertions, or deletions curated from the scientific literature. A Strict RGI match has a BLASTP bit-score above the curated BLASTP cutoff value and contains at least one curated mutation from amongst the mapped resistance variants, while a Loose RGI match has a bit-score less than the curated BLASTP bit-score cut-off but still contains at least one curated mutation from amongst the mapped resistance variants.

Bit-score Cut-off (blastP): 450


  • discovered in clinical, agricultural, or environmental isolates

  • discovered via laboratory selection experiments

  • ReSeqTB https://platform.reseqtb.org

Published Variants:

PMID: 20855724G68D Q72K H159D -nt364:445 -nt391:30 -nt76:2

>gb|AJF82049.1|-|LpxA [Acinetobacter baumannii]

>gb|CP010781.1|-|2255675-2256463|LpxA [Acinetobacter baumannii]