Pyomelanin Secretion in Madurella mycetomatis Interferes with Spectrophotometric Endpoint Reading Using the Sensititre YeastOne alamarBlue Assay but Not with Visual Endpoint Reading

B Nyuykonge; P D Croughs; A H Fahal; A Verbon; W W J van de Sande

doi:10.1128/AAC.01532-19

Pyomelanin Secretion in Madurella mycetomatis Interferes with Spectrophotometric Endpoint Reading Using the Sensititre YeastOne alamarBlue Assay but Not with Visual Endpoint Reading

Antimicrob Agents Chemother. 2019 Dec 20;64(1):e01532-19. doi: 10.1128/AAC.01532-19. Print 2019 Dec 20.

Authors

B Nyuykonge¹, P D Croughs¹, A H Fahal², A Verbon¹, W W J van de Sande³

Affiliations

¹ Erasmus Medical Center, Department of Medical Microbiology and Infectious Diseases, Rotterdam, The Netherlands.
² Mycetoma Research Center, Khartoum, Sudan.
³ Erasmus Medical Center, Department of Medical Microbiology and Infectious Diseases, Rotterdam, The Netherlands [email protected].

Abstract

The use of the Sensititre YeastOne YO10 alamarBlue assay for the in vitro susceptibility testing of Madurella mycetomatis was evaluated in M. mycetomatis isolates with and without pyomelanin secretion. Pyomelanin secretion did not influence visual endpoint reading; however, it caused a shift in peak absorbance from 570 nm to 620 nm when read spectrophotometrically. Therefore, when choosing the method for endpoint reading, the presence of pyomelanin should be considered.

Keywords: Madurella mycetomatis; azole; melanin; mycetoma; pigment; pyomelanin; susceptibility testing.

MeSH terms

Azoles / metabolism
Madurella / genetics
Madurella / metabolism*
Melanins / genetics
Melanins / metabolism*
Mycetoma / metabolism*

Substances

Azoles
Melanins
pyomelanin