ABSTRACT
Appropriate methodology for storage biological materials, extraction of DNA, and proper DNA preservation is vital for studies involving genetic analysis of insects, bacteria, and reservoir hosts as well as for molecular diagnostics of pathogens carried by vectors and reservoirs. Here we tried to evaluate the utility of a simple filter paper-based for storage of insects, bacteria, rodent, and human DNAs using PCR assays. Total body or haemolymph of individual mosquitoes, sand flies or cockroaches squashed or placed on the paper respectively. Extracted DNA of five different bacteria species as well as blood specimens of human and great gerbil Rhombomys opimus was pipetted directly onto filter paper. The papers were stored in room temperature up to 12 months during 2009 until 2011. At monthly intervals, PCR was conducted using a 1-mm disk from the DNA impregnated filter paper as target DNA. PCR amplification was performed against different target genes of the organisms including the ITS2-rDNA of mosquitoes, mtDNA-COI of the sand flies and cockroaches, 16SrRNA gene of the bacteria, and the mtDNA-CytB of the vertebrates. Successful PCR amplification was observed for all of the specimens regardless of the loci, taxon, or time of storage. The PCR amplification were ranged from 462 to 1500 bp and worked well for the specified target gene/s. Time of storage did not affect the amplification up to one year. The filter paper method is a simple and economical way to store, to preserve, and to distribute DNA samples for PCR analysis
ABSTRACT
Plant extracts and oils may act as alternatives to conventional pesticides for malaria vector control. The aim of this study was to evaluate the larvicidal activity of essential oils of three plants of Apiaceae family against Anopheles stephensi, the main malaria vector in Iran. Essential oils from Heracleum persicum, Foeniculum vulgare and Coriandrum sativum seeds were hydro distillated, then their larvicidal activity were evaluated against laboratory-reared larvae of An. stephensi according to standard method of WHO. After susceptibility test, results were analysis using Probit program. Essential oils were separated from H. persicum, F. vulgare and C. sativum plants and their larvicidal activities were tested. Result of this study showed that F. vulgare oil was the most effective against An. stephensi with LC[50] and LC[90] values of 20.10 and 44.51 ppm, respectively. All three plants essential oil can serve as a natural larvicide against An. stephensi. F. vulgare oil exhibited more larvicidal properties
ABSTRACT
Visceral leishmaniasis is caused by Leishmania infantum, transmitted to humans by bites of phlebotomine sand flies and is one of the most important public health problems in Iran. To identify the vector[s], an investigation was carried out in Bilesavar District, one of the important foci of the disease in Ardebil Province in northwestern Iran, during July-September 2008. Using sticky papers, 2,110 sand flies were collected from indoors [bedroom, guestroom, toilet and stable] and outdoors [wall cracks, crevices and animal burrows] and identified morphologically. Species-specific amplification of promastigotes revealed specific PCR products of L. infantum DNA. Six sand fly species were found in the district, including: Phlebotomus perfiliewi transcaucasicus, P. papatasi, P. tobbi, P. sergenti, Sergentomyia dentata and S. sintoni. Phlebotomus perfiliewi transcaucasicus was the dominant species of the genus Phlebotomus [62.8%]. Of 270 female dissected P. perfiliewi transcuacasicus, 4 [1.5%] were found naturally infected with promastigotes. Based on natural infections of P. perfiliewi transcaucasicus with L. infantum and the fact that it was the only species found infected with L. infantum, it seems, this sand fly could be the principal vector of visceral leishmaniasis in the region