Efficiency of the flotation method in the isolation ofPenicillium marneffeifrom seeded soil

Environmental detection of Penicillium marneffei and growth in soil microcosms in competition with Talaromyces stipitatus

“…Since the detectable level of inoculated soil at 0 d was 10 5 spores, but after 14 d detection was possible in the microcosms to which 10 3 spores were added, DNA extraction has increased 100-fold. This presumably reflects an increase in fungal biomass over the 14 d. P. marneffei has also been isolated from inoculated sterile Thai soil in two other studies (Vanittanakom et al 1995). The model microcosm experiments demonstrated that, when in direct competition with a closely related Trichocomaceae species, P. marneffei establishment and growth was not significantly affected.…”

“…P. marneffei is not very competitive with soil microflora and microfauna in non-sterile microcosms and DNA was below the limits of detection by 14 d after inoculation. The only other studies to date examining the efficacy of detecting P. marneffei in seeded non-sterile and sterile soil used traditional culturing methods (Vanittanakom et al 1995;Joshi et al, 2003). In Vanittanakom et al's study the recovery rate from 100 P. marneffei spores in non-sterile soil was 6 % compared to 84.3 % from sterile soil, mirroring our finding that P. marneffei does not flourish naturally in soil.…”

“…From each site, 20 g of soil was taken from the 'A' subsurface soil horizon to a maximum depth of 5 cm. Total DNA was extracted from the soil samples using a modified flotation method (Larsh et al 1953;Vanittanakom et al 1995). Briefly, 30 ml of phosphate buffered saline (PBS) solution was added to 15 g soil in a 50 ml tube (Nunc GmbH & Co. KG, Wiesbaden, Germany).…”

Random amplified polymorphic DNA (RAPD) analysis of Penicillium marneffei strains isolated from AIDS patients in Thailand

“…Ajello et al (1995) reported that most bamboo rats (Cannomys bad/us and Rhizomys pruinosus) are carriers of the fungus and suggested a close association between these animals and humans in its infection. Epidemiological studies by other researchers (Drouhet, 1993;Vanittanakom et al, 1995) have also suggested that bamboo rats in Thailand are hosts of P. marneffei. However, it is still controversial whether Fig.…”

Thermally Dimorphic Human Fungal Pathogens—Polyphyletic Pathogens with a Convergent Pathogenicity Trait

“…Despite its prototrophy and ability to grow on a wide range of nutrient sources, suggestive of a saprophytic lifestyle in the hyphal form, T. marneffei is almost always associated with bamboo rats in the environment (for review, see Vanittanakom et al 2006). Part of the reason for this may lie in the fact that it is relatively slow growing and may not compete well with other microbes in the soil (Vanittanakom et al 1995;Joshi et al 2003). The bamboo rat as an environmental niche may have contributed to the evolution of its pathogenic potential and it is unclear whether the yeast growth form is found outside mammalian hosts.…”