21 research outputs found

    Evaluation of the Time Course on the Effectiveness of WHO Standard Pyrethroid and Carbamate Impregnated Test Papers against Anopheles stephensi, the Main Malaria Vector in Iran

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    Background: Anopheles stephensi is a major vector of malaria in some parts of the world. A standard method for de­termining resistance in adult mosquito populations is the bioassay test recommended by the world health organization (WHO). The papers used in this method have an expiry date. This study aimed to determine the effectiveness of outdat­ed susceptibility test papers for use in insecticide resistance monitoring programs. Methods: Beech and Bandar Abbas strains of An. stephensi were reared in the insectary. Permethrin 0.75%, Deltame­thrin 0.05%, and Bendiocarb 0.1% impregnated test papers prepared by Universiti Sains Malaysia were used. Probit analysis was used to analyze the results and prepare time-mortality regression lines of LT50 and LT90. Results: There was a difference in the mortality of both tested strains of An. stephensi was exposed to all tested insecti­cides. Both expired and not expired Permethrin and Deltamethrin papers induced 100% mortality at the diagnostic time (60min), but their insecticidal properties were reduced gradually in serial times. The highest efficacy of test papers was in the first trimester after the expiry date and decreased over time. Conclusion: At the diagnostic time of 60 minutes, the mortality rate of both dated and expired papers was 100% in the pyrethroid insecticides, even three years after expiry dates, if stored in the package provided by the producer, in a re­frigerator. This value was reduced to less than 100% in the expired papers of Bendiocarb comparing the dated papers that induced 100% mortality

    Kdr genotyping and the first report of V410L and V1016I kdr mutations in voltage-gated sodium channel gene in Aedes aegypti (Diptera: Culicidae) from Iran

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    Background: Aedes aegypti is the main vector of arboviral diseases worldwide. The species invaded and became established in southern Iran in 2020. Insecticide-based interventions are primarily used for its control. With insecticide resistance widespread, knowledge of resistance mechanisms is vital for informed deployment of insecticidal interventions, but information from Iranian Ae. aegypti is lacking. Methods: Fifty-six Ae. aegypti specimens were collected from the port city of Bandar Lengeh in Hormozgan Province in the South of Iran in 2020 and screened for kdr mutations. The most common kdr mutations in Latin America and Asia (V410L, S989P, V1016G/I and F1534C), especially when present in combinations, are highly predictive of DDT and pyrethroid resistance were detected. Phylogenetic analyses based on the diversity of S989P and V1016G/I mutations were undertaken to assess the phylogeography of these kdr mutations. Results: Genotyping all four kdr positions of V410L, S989P, V1016G/I and F1534C revealed that only 16 out of the 56 (28.57%) specimens were homozygous wild type for all kdr mutation sites. Six haplotypes including VSVF (0.537), VSVC (0.107), LSVF (0.016), LSIF (0.071), VPGC (0.257) and LPGC (0.011) were detected in this study. For the first time, 11 specimens harbouring the V410L mutation, and 8 samples with V1016I mutation were found. V410L and V1016I were coincided in 8 specimens. Also, six specimens contained 1016G/I double mutation which was not reported before. Conclusions: The relatively high frequency of these kdr mutations in Iranian Ae. aegypti indicates a population exhibiting substantial resistance to pyrethroid insecticides, which are used widely in control operations and household formulations. The detection of the 410L/1016I kdr mutant haplotype in Iranian Ae. aegypti suggests possible convergence of invasive populations from West Africa or Latin America. However, as Iran has very limited maritime/air connections with those African countries, a Latin American origin for the invasive Ae. aegypti in Iran is more plausible

    The survey statistical and biological of sturgeon in the southern Caspian Sea (Mazandaran waters)

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    This study have been conducted entitle biological and statistical sturgeon in the southern Caspian Sea (Mazandaran waters)” from 2009 to 2013. Sampling was manthly. Overal, 1859 specimens of different species of sturgeon was caught including Acipenserpersicus (69%), A. stellatus (19%), Husohuso (6%), A. nudiventris (4%) and A. guldenstaedtii (2%). Totally, the meat and caviar of five species were found 53263.6 kg and 5633 kg respectively and caviar to meat ratio was 10.6%. The results show that ration of meat and caviar whole species reduced from 2009 to 2012 in which the meat and caviar of A. persicus was declined from 12146 to 4465 kg in meat and caviar from 1358 to 487 kg were extremely reduced respectively. The CPUE (catch per unit effort) of sturgeon has fluctuated from 2009 to 2012. Totally, the CPUE of A. persicus was decreased from 0.150 (2009) to 0.130 (2012) kg boat per day, A. stellatue from 0.009 (2009) to 0.021 (2012) kg boat/day, A. guldenstaedtii from 0.002 (2009) to 0.003 (2012) kg boat/day, A. nudiventris from 0.027 (2009) to 0.001 (2012) kg boat/day and H. huso from 0.123 (2009) to 0.018 (2012) kg boat /day. 1061 specimens of fish has been caviar including A. persicus with 69%, A. stellatus (18.1%), H. huso (5.5%), A. guldenstaedtii (2.7%). The frequency of caviar categorize was included 1 , 2, 3 and massive with 49.6%, 38%), 10.6% and 1.9% , respectively. The highest of meat and caviar belong to A. persicus with 31414 kg and 3515.7 kg, respectively were found and the lowest was 841kg and 105.9 kg pertain to A. guldenstaedtii. The results show that 65.9% of sturgeon was caught by legal catch (landing) and 34.1% by beach seine remained. 391 individuals was age determined that the minimum and maximum age was 9 and 41 year comprised to H.huso and A. stellatus, respectively. A. persicus and A. stellatus were majority caught compare to other species. A. persicus has the highest frequency in 14-15 year age groups with 50% and 57% in 2009 and 2011, respectively and 15-16 year age group with 41% and 56% in 2010 and 2012, respectively. The results show that mean of fork length, body weight, caviar weight of A. persicus was declined because the FL and weight average (±SD) obtained from 152.4±16.7cm and 25.8±9.2 kg in 2009 to 146.5± 18.7cm and 22.1±9.2kg in 2012, respectively. In contrast, the average (±SD) FL and weight of H. huso was increased from 218.8±41.1cm and 137.3±96.6kg in 2009 to 231.3±45.2cm in FL and 146.2±78.5kg body weight in 2012, respectively. Consequently, the results show that stocks of sturgeon in the Caspian Sea has a trend declined because of some species in IUCN categorize list was Endangered in 2006 but at this moment lie in Critically Endangered list of IUCN categorize were down which could be a serious alarm for the valuable sturgeon fish in the Caspian Sea. Therefore, recommendation that trade catch of sturgeon in the Caspian Sea must be forbidden and continue legal catch for spawner fish that needede to artificial propagation only

    Ecology of Malaria Vectors in an Endemic Area, Southeast of Iran

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    Background: Malaria has long been regarded as one of the most important public health issues in Iran. Although the country is now in the elimination phase, some endemic foci of malaria are still present in the southeastern areas of the country. In some endemic foci, there are no data on the malaria vectors. To fill this gap, the present study was designed to provide basic entomological data on malaria vectors in the southeastern areas of Iran. Methods: Adult and larval stages of Anopheles mosquitoes were collected by using different catch methods. Resistance of the main malaria vector in the study area to selected insecticides was evaluated using diagnostic doses advised by the World Health Organization in 2013–2014. Results: A total of 3288 larvae and 1055 adult Anopheles mosquitoes were collected, and identified as: Anopheles ste­phensi (32.1%), Anopheles culicifacies s.l. (23.4%), Anopheles dthali (23.2%), Anopheles superpictus s.l. (12.7%), and Anopheles fluviatilis s.l. (8.6%). Anopheles stephensi was the most predominant mosquito species collected indoors at the study area, with two peaks of activity in May and November. This species was found to be resistant to DDT 4%, tolerant to malathion 5% and susceptible to other tested insecticides. Conclusion: All the five malaria vectors endemic to the south of Iran were collected and identified in the study area. Our findings on the ecology and resting/feeding habitats of these malaria vectors provide information useful for plan­ning vector control program in this malarious area

    Evaluation of expression variations in virulence-related genes of Leishmania major after several culture passages compared with Phlebotomus papatasi isolated promastigotes

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    Cutaneous leishmaniasis (CL) is a prevalent infectious disease with considerable morbidity annually. Here, we aimed to investigate the likely variations in gene expression of glycoprotein63 (gp63), heat shock protein 70 (HSP70), histone, arginase, cysteine protease B (CPB), Leishmania homologue of receptors for activated C kinase (LACK), small hydrophilic endoplasmic reticulum-associated protein (SHERP) in metacyclic promastigotes of L. major isolated from Phlebotomus papatasi sand flies and promastigotes excessively cultured in culture medium. The parasites were collected from suspected CL cases in Pasteur Institute of Iran, cultured and inoculated into the female BALB/c mice (2×106 promastigotes). Sand flies were trapped in Qom province, fed with the blood of euthanized infected mice and subsequently dissected in order to isolate the midgut including stomodeal valve. The metacyclic promastigotes were isolated from Ph. papatasi (Pro-Ppap) using peanut agglutinin test (PNA), then continuously cultured in RPMI-1640 medium enriched with fetal bovine serum, penicillin (100 U/ml) and streptomycin (100 mg/ml) to reach stationary phase (Pro-Stat). The gene expression was evaluated in both parasitic stages (Pro-Ppap and Pro-Stat) using qRT-PCR. Out results showed a significant increased gene expression at Pro-Ppap stage for gp63 (P = 0.002), SHERP (P = 0.001) and histone (P = 0.026) genes, in comparison with Pro-Stat stage. Noticeably, significant changes were, also, demonstrated in 10th to 15th passages [gp63 (P = 0.041), arginase (P = 0.016), LACK (P = 0.025)] and in 5th to 20th passage (SHERP) (P = 0.029). In conclusion, the findings of the present study seem to be essential in designing Leishmania studies, in particular regarding host-parasite interaction, immunization and infectivity studies

    DNA barcodes corroborating identification of mosquito species and multiplex real-time PCR differentiating Culex pipiens complex and Culex torrentium in Iran.

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    Identifying mosquito species is a fundamental step in risk assessment and implementation of preventative strategies. Moreover, Culex pipiens is the most widespread mosquito vector in several regions of Iran and is the main vector for transmission of West Nile virus (WNV). Mosquitoes were collected at 14 sites in northern regions of Iran in 2015 and 2016. A subset of mosquito specimens was selected for identification confirmation using a DNA-barcoding technique. Construction of a phylogenetic tree showed clustering of mosquito sequences into three main genera: Aedes, Anopheles and Culex with individuals of a single species clustered closely together, regardless of where and when they were collected. Cx. pipiens complex and Cx. torrentium were identified and differentiated using multiplex real-time PCR targeting the gene locus for acetylcholinesterase 2 (ace2) to discriminate between Cx. pipiens pipiens and Cx. torrentium. The CQ11 microsatellite locus was used for discrimination between Cpp. biotypes. The predominant mosquito species in investigated regions were Cx. pipiens pipiens biotype pipiens, but we also detected Culex pipiens pipiens biotype molestus and hybrids of the two pipiens biotypes, as well as Cx. torrentium. The results of this study represent the first certain evidence of the presence of Cx. pipiens pipiens biotype molestus and hybrids between pipiens and molestus forms, and Cx. torrentium in Iran through a molecular identification approach. This report of a potentially important bridge vector for WNV might have key influence in the risk projections for WNV in Iran

    Entomological surveillance of invasive Aedes mosquitoes in Mazandaran Province, northern Iran from 2014 to 2020

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    Abstract Mosquitoes are the most important vectors of serious infectious diseases in the world. Dengue, Zika, chikungunya and yellow fever are emerging and re-emerging infectious diseases, associated with the distribution of two key vectors i.e. Aedes aegypti and Aedes albopictus throughout the world including countries neighbouring Iran. Entomological surveillance was planned and performed monthly from May to December during 2014–2020 in selected counties of Mazandaran Province, North of Iran, by ovitrap, larval collection, hand catch and human baited trap. Overall, 4410 Aedes specimens including 2376 larvae (53.9%) and 2034 (46.1%) adults belonging to six species, namely Aedes vexans, Aedes geniculatus, Aedes caspius, Aedes echinus, Aedes pulcritarsis and Aedes flavescence were collected and morphologically identified. Over the seven years of surveillance, Ae. aegypti and Ae. albopictus were not found by any sampling method. Aedes vexans and Ae. geniculatus were the most abundant species, their populations peaked in October and November and was positively correlated with precipitation and relative humidity. Aedes flavescence was a new species record for the province. A flowchart for planning and implementation of invasive mosquito surveillance for provincial health authorities in the country is proposed. These surveillance efforts provide basic and timely information for the health system to act promptly on integrated and intensified surveillance and control programs should Ae. aegypti and Ae. albopictus detected in the province
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