Objective: To evaluate the larvicidal activity of the ethanolic and aqueous extracts of the endocarp and seeds of Dracaena loureiri (D. loureiri) against the dengue mosquito vector, Aedes aegypti. Methods: Bioassays were performed by exposing late third-stage to early fourth-stage larvae of Aedes aegypti to various concentrations of the extracts from D. loureiri. The larval mortality was observed after 24-and 48-h exposure. Results: The larvicidal bioassay in this study demonstrated that the ethanolic endocarp extract was the most effective with the LC50 value of 84.00 mg/L after 24 h exposure and< 50 mg/L after 48 h exposure. Extracts from the other parts of the plant were signifi-cantly less effective as a larvicide. Conclusions: The ethanolic endocarp extract of D. loureiri demonstrated effective lar-vicidal activity. It is an alternative source for developing a novel larvicide for controlling this mosquito species.

Objective:To investigate the prevalence of Candida spp.and the virulence factors of Candida albicans (C.albicans) isolated from external surfaces of blow flies collected from Mae Sot,Tak Province,Thailand,Methods:The blow flies were collected by sterile sweep nets from three areas in Mae Sot.Yeast isolation was first performed on Sabouraud dextrose agar (SDA) supplemented with chloramphenicol and cycloheximide.The yeast isolates were then identified by using chromogenic agar,a yeast identification test kit,a germ tube formation test and a carbohydrate utilization test.The β-hemolysis was determined on 7％ sheep blood agar,while phospholipase activity was measured on SDA agar supplemented with 10％ egg yolk suspension.Antifungal susceptibility testing was determined by broth micro-dilution testing against ketoconazole and amphotericin B.Results:The prevalence rate of Candida spp.on the external surfaces of the blow flies was 78.1％.All C.albicans isolated from the blow fly demonstrated β-hemolysin and potent phospholipase activities and 47.1％ of C.albicans were resistant to ketoconazole with MIC values 128 μg/mL.Conclusions:The result s indicate that blow flies could play an essential role in the transmission of potentially pathogenic and antifungal resistant C.albicans into the environment.Further investigation on other virulence factors and genetic relatedness among isolates from the blow flies,the environment and clinical specimens is required to confirm this role.

Objective: To evaluate the larvicidal efficacy of crude and fractionated extracts of Dracaena loureiri endocarp against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Anopheles minimus mosquitos. Methods: Larvicidal activity was tested according to World Health Organization standard protocol. The third-stage larvae of each mosquito species were exposed to various concentrations of Dracaena loureiri crude extract and six groups of Dracaena loureiri fractionated extracts (RC-DT 009-014). Larval mortality rates were observed after 24 h and 48 h of exposure. Then, a computerized probit analysis of the mortality data was performed to determine lethal concentration 50 (LC

Objective: To investigate the susceptibility to temephos, permethrin and deltamethrin of Aedes aegypti (. Ae. aegypti), collected from areas with high incidence of dengue hemorrhagic fever cases in Phitsanulok Province, Thailand. Methods: The F1 progenies of Ae. aegypti colony, originated from five sub-districts including Aranyik, Hua Ro, Nai Muang, Ban Krang and Tha Pho, were used in the bioassays following the procedures of World Health Organization. For larval bioassay, the late third or early fourth-instar larvae were tested with different concentrations of temephos. For adult bioassay, the females were exposed to 0.75 % permethrin or 0.05% deltamethrin. LC50 value and mortality rate were analyzed to compare the insecticide susceptibility of the larvae and the adults in each area, respectively. Results: The LC50 value of temephos for the larvae from Aranyik, Hua Ro, Nai Muang, Ban Krang and Tha Pho sub-districts was 0.017, 0.017, 0.026, 0.061, and 0.113 ppm, respectively. For permethrin, the highest mortality rate (86.84%) was found in the mosquitoes from Aranyik but the others were more resistant with the lower mortality rates (16.00-42.67%). The adult mortality rates after exposing to deltamethrin were higher (82.34-98.67%) in all areas. Conclusions: Ae. aegypti larvae were still susceptible to temephos. Conversely, most tested adults tended to resist the permethrin and deltamethrin.

Objective To evaluate the larvicidal activity of the ethanolic and aqueous extracts of the endocarp and seeds of Dracaena loureiri (D. loureiri) against the dengue mosquito vector, Aedes aegypti. Methods Bioassays were performed by exposing late third-stage to early fourth-stage larvae of Aedes aegypti to various concentrations of the extracts from D. loureiri. The larval mortality was observed after 24- and 48-h exposure. Results The larvicidal bioassay in this study demonstrated that the ethanolic endocarp extract was the most effective with the LC

Objective To investigate the prevalence of Candida spp. and the virulence factors of Candida albicans (C. albicans) isolated from external surfaces of blow flies collected from Mae Sot, Tak Province, Thailand. Methods The blow flies were collected by sterile sweep nets from three areas in Mae Sot. Yeast isolation was first performed on Sabouraud dextrose agar (SDA) supplemented with chloramphenicol and cycloheximide. The yeast isolates were then identified by using chromogenic agar, a yeast identification test kit, a germ tube formation test and a carbohydrate utilization test. The β-hemolysis was determined on 7% sheep blood agar, while phospholipase activity was measured on SDA agar supplemented with 10% egg yolk suspension. Antifungal susceptibility testing was determined by broth micro-dilution testing against ketoconazole and amphotericin B. Results The prevalence rate of Candida spp. on the external surfaces of the blow flies was 78.1%. All C. albicans isolated from the blow fly demonstrated β-hemolysin and potent phospholipase activities and 47.1% of C. albicans were resistant to ketoconazole with MIC values 128 μg/mL. Conclusions The results indicate that blow flies could play an essential role in the transmission of potentially pathogenic and antifungal resistant C. albicans into the environment. Further investigation on other virulence factors and genetic relatedness among isolates from the blow flies, the environment and clinical specimens is required to confirm this role.