Monitoring of Laboratory Reared of Phlebotomus papatasi (Diptera: Psychodidae), Main Vector of Zoonotic Cutaneous Leishmaniasis to Different Imagicides in Hyper endemic Areas, Esfahan Province, Iran.

BACKGROUND: In domestic and per domestic area, insecticides such as DDT, malathion, fenitrothion, propoxur and, more recently, synthetic pyrethroids such as deltamethrin and lambda-cyhalothrin, have been successfully used to control sand flies in many countries. The present study reports the results of time-mortality bioassay to DDT 4%, lambda-cyhalothrin 0.05%, permethrin 0.75%, cyfluthrin 0.15% and deltamethrin 0.05% in recently colonized Phlebotomus papatasi populations in Iran. METHODS: The insecticide susceptibility status of P. papatasi laboratory population was assessed during 2016-2017, following the standard WHO technique for mosquito (WHO, 2013) based on diagnostic dose. Sand flies collected from rural area of Badrood (Matin Abad), Natanz County, Esfahan Province, using aspirator. RESULTS: Susceptibility test to DDT and pyrethroids was assessed on 3534 laboratory-reared P. papatasi (1746 females and 1788 males). The LT 50 and LT 90 values were measured using probit analysis and regression lines. The test results against males of P. papatasi revealed that LT 50 values to DDT 4%, Permethrin 0.75%, Deltamethrin 0.05%, Cyfluthrin 0.15% and Lambdacyhalothrin 0.05% were 439.28, 108.90, 97.75, 5.00 and 57.84 seconds. The figures for females were 641.62, 136.15, 146.44, 8.71 and 72.69 seconds, respectively. CONCLUSION: According to presented results, the reared population of sand flies collected from a hyper-endemic region of Esfahan Province is still susceptible to prethroids and Resistance candidate to DDT 4%.

The Potential Role of Humans in the Transmission Cycle of Leishmania major (Kinetoplastida: Trypanosomatidae), the Causative Agent of the Old World Zoonotic Cutaneous Leishmaniasis.

Zoonotic cutaneous leishmaniasis (ZCL) due to Leishmania major (Yakimoff and Schokhor, 1914) is known as a neglected tropical disease, transmitted by Phlebotomus papatasi (Scopoli, 1786) in North Africa and the Middle East. The main reservoirs of ZCL are desert gerbils and the role of humans as a reservoir host of the disease is not clearly defined and is therefore investigated in this study. In order to achieve this objective, Ph. papatasi sand flies were allowed to take blood through indirect blood sources (human, Rhombomys opimus (Lichtenstein, 1823) (great gerbil), and BALB/c mice) using artificial feeding or direct xenodiagnoses from ZCL patients. To detect Leishmania promastigotes inside digestive canal, blood-fed sand flies were dissected and examined under light microscope and then confirmed by nested-PCR. In indirect xenodiagnoses, promastigote forms of Leishmania parasite were observed in 7.1%, 12%, and 13.6% of sand flies which fed on Rh. opimus, BALB/c mice, or human blood sources, respectively. In direct xenodiagnoses, among 93 female lab-reared sand flies which fed on active L. major lesion(s), 2.1% Leishmania infection was subsequently observed in the sand flies. No infection was detected in those sand flies that fed on nonlesioned skin of CL patients. Humans can serve as a reservoir of ZCL since the data indicate that Ph. papatasi is able to acquire L. major parasites from an active lesion of ZCL patients and the parasites can complete metacyclogenesis in the sand fly.

Rearing and Biology of Phlebotomus sergenti, the Main Vector of Anthroponotic Cutaneous Leishmaniasis in Iran.

BACKGROUND: Establishment of sand flies laboratory colonies is essential to understand various biological aspects of Phlebotominae sand flies. The aims of the current study were to establish the colony of Phlebotomus sergenti Parrot (1917), the main vector of anthroponotic cutaneous leishmaniasis in old world, and to study biological parameters of this species. METHODS: The sand flies were reared at 26-28 °C temperature, 14:10 (light: dark) photoperiod and 70-80% relative humidity. Larval diet was a composted mixture of rabbit faces and rabbit pellets which is prepared through a special process. First to fifth generations of P. sergenti were used to define biological parameters. RESULTS: Results showed that, P. sergenti blood feeding percentage were 42% on chicken, 21% on BALB/c and 37% on golden hamster. Average time of blood digestion, egg incubation, 1st instar larva, pupa and adult emerging was recorded at 3.4, 8.7, 15, 33.3 and 41.2 days after blood feeding, respectively. Mean number of laid eggs was 55.1 and retained eggs were 35 per a female. Fecundity and production rate were 61.6%, and 42.2% respectively. Average longevity recorded at 15.2 days for females and 14.8 days for males. CONCLUSION: Colony of P. sergenti has been established for the first time in Iran. Average interval time from egg to adult of this species was 32.5 days. Chicken and golden hamster were recommended as a blood source for colony initiation and routine blood feeding, respectively.

Separation of Biogas Components with Single Wall Carbon Nanotubes: a GCMC Simulation.

Biogas is a green energy source that mainly contains CH4, CO2 ,traces of H2S and fractions of H2O vapor. One of the effective methods in biogas treatment from its pollutants is adsorptive separation. Here, enrichment of methane using (10, 10) and (6, 6) carbon nanotubes (CNTs) in modelled biogas consisting CH4, CO2 and H2S is studied. Simulations were carried out using Grand Canonical Monte Carlo (GCMC) method. Adsorption isotherms obtained at various temperatures and pressures for two single wall carbon nanotubes (SWCNTs). To quantify the separation ability of the nanotubes the adsorptive separation factors for H2S/CH4 and CO2/CH4 were calculated. For studding temperature effect, simulations at two (0.1 and 1 MPa) pressures and four temperatures: 288, 298, 318 and 338 K have been performed. In all studied conditions, CO2 is preferentially adsorbed by CNTs. Results have shown that the two separation factors are considerable, particularly for (10, 10) CNT. Additionally, the adsorption and selectivity behaviour of studied gases were considered in (6,6), (8,8) and (10,10) CNT hexagonal bundles for comparison. The results for single nanotubes were confirmed with the bundles. Hence, despite lower concentration of CO2 than CH4 and trace amount of H2S in biogas, they can be separated from methane effectively by CNTs as adsorbents. Our results showed that the CNTs can be remarkable tools in methane separation from biogas.