Different culture media containing methyldopa for melanin production by Cryptococcus species

Abstract

<jats:p>INTRODUCTION: Melanin production by species of Cryptococcus is widely used to characterize C. neoformans complex in mycology laboratories. This study aims to test the efficacy of methyldopa from pharmaceutical tablet as a substrate for melanin production, to compare the production of melanin using different agar base added with methyldopa, and to compare the melanin produced in those media with that produced in Niger seed agar and sunflower seed agar by C. neoformans, C. laurentii, and C. albidus. Two isolates of each species, C. neoformans, C. laurentii, and C. albidus, and one of Candida albicans were used to experimentally detect conditions for melanin production. METHODS: The following media were tested: Mueller-Hinton agar (MHA), brain and heart infusion agar (BHIA), blood agar base (BAB), and minimal medium agar (MMA), all added with methyldopa, and the media Niger seed agar (NSA) and sunflower seed agar (SSA). RESULTS: All isolates grew in most of the culture media after 24h. Strains planted on media BAB and BHIA showed growth only after 48h. All isolates produced melanin in MMA, MHA, SSA, and NSA media. CONCLUSIONS: Methyldopa in the form pharmaceutical tablet can be used as a substrate for melanin production by Cryptococcus species; minimal medium plus methyldopa was more efficient than the BAB, MHA, and BHIA in the melanin production; and NSA and SSA, followed by MMA added with methyldopa, were more efficient than other media studied for melanin production by all strains studied.</jats:p>

Development and validation of benomyl birdseed agar for the isolation of Cryptococcus neoformans and Cryptococcus gattii from environmental samples

“…These two growth media are non-selective and allow the overgrowth of fast-growing and abundant environmental molds and yeasts, which can obscure and obstruct the isolation of C. neoformans and C. gattii . Over the years, there have been numerous improvements in differential media for these two species of Cryptococcus [18,19,20]. However, selective medium for these organisms can be improved.…”

Development of Modified Selective Media to Differentiate Cryptococcus Species Complex and its Serotypes using Natural Materials

“…Cryptococcus species complex cannot produce melanin pigment without certain exogenous substrates (Casadevall et al, 2003;Eisenman et al, 2011;Garcia-Rivera et al, 2005). Based on this idea, several modified culture media were developed for the rapid identification of Cryptococcus species complex, such as mustard seed, chili pepper, Pinus halepensis seed, Eggplant, benomyl bird seed and blackberry agar (Menezes et al, 2011;Mseddi et al, 2011;Nandhakumar et al, 2006;Pedroso et al, 2007;Pham et al, 2014;Sengul et al, 2014). However, there are some limits.…”

“…Although isolation and identification of these fungal pathogens from clinical sources is very important for patients, as cryptococcosis is a lifethreatening infection, they are time-consuming and complicated processes. Diagnosis of Cryptococcus species complex from clinical materials is generally based on the observation capsule of yeasts by direct microscopy; culture and biochemical tests are subsequently required for isolation and identification of these fungal pathogens (Negroni, 2012 (Eisenman et al, 2011;Menezes et al, 2011). However, these selective culture media have some limits.…”

In vitro antifungal activities of leaf extracts of Lippia alba (Verbenaceae) against clinically important yeast species

“…Cryptococcus gattii causes cryptococcal infections mostly in immunocompetent individuals 4 . Despite some effective treatment options, such mycoses are associated with high morbidity 2 .…”