Abstract: Objective To analyze the sequence of rDNA ITS of Penicillium marneffei for developing an accurate diagnosis method of P. marneffei. Methods Four strains of P.marneffei were collected from different areas in China. Fungal general primers (ITS1 and ITS4) were used to amplify the internal transcribed spacer of rDNA of P. marneffei. The PCR products were purified and sequenced directly. Then the sequences were analyzed by comparing with the gene bank. Results The results showed that the four strains of P. marneffei shared almost the same rDNA ITS sequence which was similar with the data from different areas, such as the United States, Indonesia, France and Australia. The rDNA ITS sequences of P. marneffei were quite differenct from Histoplasma capsulatum, Cryptococcus neoformans and Candida species. The rDNA ITS sequences of Penicillium and Aspergillus share lower similarities, while there was no obvious difference of rDNA ITS sequences among Penicillium species. Conclusions rDNA ITS sequences among P. marneffei strains from different areas and even among different Penicillium species are highly homogenous, which suggest that this region may not be suitable as the target gene for designing species-specific primers or probes.

Key words: Penicillium, DNA, ribosomal spacer