PMID:15917566 Targeted gene disruption of the 14-alpha sterol demethylase (cyp51A) in Aspergillus fumigatus and its role in azole drug susceptibility.

[MPiovesana]

Curated by @MPiovesana https://canto.phi-base.org/curs/677cbb5161c74ea6

[MPiovesana]

The cyp51A gene of Aspergillus fumigatus strain CM-237 was disrupted by a hygromycin B resistance cassette (Figure 1), generating mutant CM-A8. Two clinical isolates of A. fumigatus were also subjected to the gene disruption protocol. The disruption mutant displayed increased susceptibility to azole fungicides, notably fluconazole and ketoconazole given that the wild type parental strain is intrinsically resistant to both chemicals. The mutation does not affect the pathogenicity of A. fumigatus when infecting mice (Figure 2).

[MPiovesana]

Uniprot ID: cyp51A of A. fumigatus was readily identified in UniprotKB; ID Q4WNT5 has also been used previously in other curation sessions.

[MPiovesana]

Genotype creation and annotations: To curate the disruption of the cyp51A gene, strain CM-237 was selected and a disruption allele was created, named cyp51A-(gene disruption). Expression levels was selected as Not assayed.

With regards to genotype annotations, the terms sensitive to fluconazole and sensitive to ketoconazole were used. Authors also test the susceptibility of wt and mutant strains to other fungicides; however, as the wt strain is not intrinsically resistant to those, in contrast to FLC and KTC, the differences in susceptibility between wt and mutant are much smaller for the other compounds, and I believe they do not need to be annotated.

[MPiovesana]

Authors also disrupt the cyp51A gene of two clinical isolates, and observe similar effects on the susceptibility of these to FLC and KTC. However, as these are not references strains, I thought it would unnecessary to annotate their genotypes. Is that ok?

[MPiovesana]

Metagenotype creation and annotation: Two metagenotypes were created in order to curate the infection assay described in the paper:

cyp51A+[WT level] and wild type Mus musculus (Unknown strain) cyp51A-(gene disruption)[Not assayed] and wild type Mus musculus (Unknown strain)

Both the control and altered metagenotypes were annotated with the PHIPO term death of host organism with pathogen, and delivery mechanism: pathogen spore inoculation was selected under Conditions. The altered metagenotype was also annotated with extensions compared_to_control and infective_ability unaffected pathogenicity, while both metagenotypes were annotated with extension interaction_outcome disease present.

[MPiovesana]

Curation completed pending review.

[CuzickA]

Hi @ValWood, I don't think I have curated many 'disruption' genotypes before. I can find an example with a t-dna insertion in https://github.com/PHI-base/curation/issues/24 where the genotype looks like this

Currently, in this chemistry paper the disruption genotype is

Do you think that it would be better modeled as 'Cyp51A::HPH cassette (disruption) not assayed'?

[ValWood]

That makes sense, Val

[CuzickA]

Genotype now updated

[CuzickA]

Session now likes this

AE alteration in archetype is N/A.

Approving session and closing ticket.