RRC ID 70187
Author Yamamoto T, Alimu Y, Takahashi H, Kusuya Y, Hosoya K, Shigemune N, Nagai S, Yaguchi T.
Title Isolation and Characterization of the Polyhexamethylene Biguanide Hydrochloride-Resistant Fungus, Purpureocillium lilacinum.
Journal Biocontrol Sci
Abstract We isolated a fungus from a 20% (= 200,000 µg/mL) aqueous solution of polyhexamethylene biguanide hydrochloride (PHMB), a widely used antimicrobial and examined its morphology and drug resistance profile. Based on the sequence of the internal transcribed spacer region of ribosomal DNA, the fungus was identified as Purpureocillium lilacinum. Although the P. lilacinum type and resistant strains showed similar morphology, the latter had extremely low PHMB susceptibility and was able to grow in 20% aqueous solution of PHMB, which eliminated the type strain. The minimum inhibitory concentration (MIC) of PHMB for the resistant strain was significantly higher than that of the type strain and other pathogenic filamentous fungi and yeasts. The susceptibility to antimicrobial agents and antifungal agents other than PHMB was similar to that of the type strain, therefore the drug resistance of the isolate was specific to PHMB. Furthermore, we sequenced the genome of the isolate to predict PHMB resistance-related genes. Despite its high resistance to PHMB, no well-known genes homologous to fungal PHMB-resistant genes were detected in the genome of the resistant strain. In summary, P. lilacinum was found to be significantly more resistant to PHMB than previously reported, via an unidentified mechanism of drug resistance.
Volume 26(3)
Pages 157-166
Published 2021-1-1
DOI 10.4265/bio.26.157
PMID 34556618
MeSH Biguanides* / pharmacology Fungi* Hypocreales Microbial Sensitivity Tests
IF 0.833
Resource
Pathogenic eukaryotic microorganisms Purpureocillium lilacinum IFM 63780