Occurrence and identification of Penicillium and Talaromyces species from beach sand

Aims@#Penicillium and Talaromyces were among the species of microfungi that inhabit beach sand in Batu Ferringhi Beach, Penang Island, Malaysia. Previously, Talaromyces was described as the sexual stage of Penicillium, but both are now accepted as separate genera based on molecular phylogeny. The aim of the present study was to identify species of Penicillium and Talaromyces that are present in beach sand in Malaysia.@*Methodology and results@#Species identities were confirmed according to similarities of the internal transcribed spacer regions and β-tubulin gene sequences and a phylogenetic analysis based on both regions/gene. Nine Penicillium spp. were identified as P. georgiense, P. chermesinum, P. pimiteouiense, P. citrinum, P. oxalicum, P. daleae, P. rolfsii and Penicillium sp. and the four Talaromyces spp. were T. siamense, T. atroroseus, T. minioluteus and T. fusiformis.@*Conclusion, significance and impact of study@#These findings showed that beach sand harboured a variety of Penicillium and Talaromyces species. The occurrence of Penicillium and Talaromyces in beach sands is associated with the organic matter in the sand, which provides suitable substrates and nutrient sources. Due to this, beach sand might harbour many potentially pathogenic or opportunistic species that may pose a health concern to immunocompromised individuals.

The use of PCR-RFLP to genetically distinguish the morphologically close species: Ceriodaphnia dubia Richard, 1894 and Ceriodaphnia silvestrii Daday, 1902 (Crustacea Cladocera) / Utilização do PCR-RFLP para diferenciar geneticamente as espécies Ceriodaphnia dubia Richard, 1894 e Ceriodaphnia silvestrii Daday, 1902 (Crustacea Cladocera)

The cladocerans are important components of planktonic and benthic freshwater and good indicators of the trophic state of water bodies. The morphological taxonomy of many species of Cladocera is considered complex with minor differences separating some species. Nowadays, molecular techniques provide a powerful tool to identify and classify different taxonomical levels, using mainly ribosomal RNA genes (rRNA) as molecular markers. In the present work we performed PCR-RFLP to separate Ceriodaphnia dubia, an exotic species in Brazil and the native species Ceriodaphnia silvestrii, widely distributed in Brazilian freshwater. The RFLP analysis of the ITS1-5.8S-ITS2 region of rRNA genes showed to be different between C. dubia and C. silvestrii when using enzymes EcoRI, ApaI and SalI. Thus, the ITS1-5.8S-ITS2 region proved to be a useful molecular marker to differentiate the studied Ceriodaphnia species, which makes the task easier of telling apart species that are morphologically very similar. Also, this methodology might be interesting in determining the distribution of the exotic species C. dubia in Brazilian freshwaters, particularly in cases when C. dubia occurs in the absence of C. silvestrii, a particularly difficult task for ecologists who are not taxonomy specialists.

Os cladóceros são considerados importantes componentes de comunidades bentônicas e planctônicas de água doce e bons indicadores do estado trófico da água. A taxonomia morfológica de muitas espécies de Cladocera é considerada complexa com pequenas diferenças que separam algumas espécies. Atualmente, as técnicas moleculares são consideradas uma ferramenta importante para identificar e classificar diferentes níveis taxonômicos, com a utilização, principalmente, de genes de rRNA como marcadores moleculares. No presente trabalho foi utilizada PCR-RFLP para diferenciar geneticamente Ceriodaphnia dubia, uma espécie exótica no Brasil, e a espécie nativa Ceriodaphnia silvestrii, amplamente distribuída em corpos d'água brasileiros. A análise por RFLP da região ITS1-5.8S-ITS2 dos genes de rRNA mostrou diferenças entre C. dubia e C. silvestrii para os sítios das enzimas de restrição EcoRI, ApaI e SalI. Dessa forma, a região ITS1-5.8S-ITS2 mostrou-se um marcador molecular útil para diferenciar as espécies de Ceriodaphnia estudadas, o que facilita a separação de espécies muito similares morfologicamente. Também, os resultados apresentados parecem ser interessantes na determinação da distribuição da espécie exótica C. dubia em corpos d'água brasileiros, principalmente nos casos onde C. dubia ocorre na ausência de C. silvestrii, uma tarefa difícil para ecologistas não especialistas em taxonomia.

PCR Amplification of 16S-23S rDNA Intergenic Spacer Regions of Bacteria in Trauma Infection by Universal Primers / 中华医院感染学杂志

OBJECTIVE To examine the feasibility of PCR amplification of 16S-23S rDNA intergenic spacer regions of bacteria in trauma infection by a pair of universal primers for gene diagnosis.METHODS The universal primers were designed at conserved regions of the 3' end of 16S rDNA and the 5' end of 23S rDNA.Bacterial genomic DNA from selected five commom bacteria in trauma infection were amplified by PCR.PCR products were examined using electrophoresis in agarose gel,and futher analyzed by sequencing.RESULTS The PCR products were similar to that we expected on the gel,which were confirmed by the results of sequencing and alignment.CONCLUSIONS Using the universal primers,16S-23S rDNA intergenic spacer regions of bacteria in trauma infection could be amplified by PCR,which lays a solid foundation for gene diagnosis in farther studies.