Differentiation of Basidiobolus spp. Isolates: RFLP of a Diagnostic PCR Amplicon Matches Sequence-Based...

Area of Science:

• Mycology
• Molecular Biology
• Infectious Diseases

Background:

• The genus Basidiobolus, known since 1886, is associated with reptiles and amphibians, with rare infections occurring globally, mainly in tropical/subtropical regions.
• Past species descriptions relied on variable morphological/physiological traits, leading to most names being synonyms of B. ranarum, the presumed sole pathogenic species.
• It remains unclear if environmental Basidiobolus isolates can be reliably distinguished, as not all are necessarily pathogenic.

Purpose of the Study:

• To determine if environmental Basidiobolus isolates can be reliably differentiated using morpho-physiological and molecular characteristics.
• To compare the efficacy of different methods for distinguishing between Basidiobolus isolates.

Main Methods:

• Morpho-physiological examination of eleven environmental isolates and one type strain (Basidiobolus microsporus DSM 3120).
• Molecular analysis including 18S and partial 28S rRNA gene sequencing.
• Restriction fragment length polymorphism (RFLP) analysis of a Basidiobolus-specific diagnostic PCR amplicon.

Main Results:

• Morphological features and 18S rRNA gene sequences were insufficient for reliable isolate differentiation.
• Isolates were distinguishable by growth temperature profiles.
• Clusters identified by 28S rRNA gene sequencing and RFLP analysis correlated with growth temperature profiles.

Conclusions:

• Partial 28S rRNA gene sequencing and RFLP analysis are effective for differentiating environmental Basidiobolus isolates.
• RFLP analysis serves as a rapid screening method for identifying Basidiobolus isolates with similar physiological traits.
• This study clarifies the differentiation of environmental Basidiobolus, impacting our understanding of their pathogenicity and distribution.