Oxfendazole flukicidal activity in pigs

Although oxfendazole (OFZ) is a well know broad-spectrum benzimidazole anthelmintic, the assessment of its potential trematodicidal activity remains unexplored. OFZ administration at single high doses has been recommended to control Taenia solium cysticercus in pigs. The current study investigated the flukicidal activity obtained after a single high (30 mg/kg) oral dose of OFZ in pigs harbouring a natural Fasciola hepatica infection. Sixteen (16) local ecotype pigs were randomly allocated into two (2) experimental groups of 8 animals each named as follow: Untreated control and OFZ treated, in which animals received OFZ (Synanthic^®, Merial Ltd., 9.06% suspension) orally at 30 mg/kg. At seven (7) days post-treatment, all the animals were sacrificed and direct adult liver fluke counts were performed following the WAAVP guidelines. None of the animals involved in this experiment showed any adverse event during the study. OFZ treatment as a single 30 mg/kg oral dose showed a 100% efficacy against F. hepatica. In conclusion, the trial described here demonstrated an excellent OFZ activity against F. hepatica in naturally infected pigs, after its administration at a single oral dose of 30 mg/kg.     

The heterolgous protection of rats against a challenge with Fasciola hepatica by prior infection with the nematode Nippostrongylus brasiliensis

Previous infection of rats with Nippostrongylus brasiliensis was shown to result in protection against an oral challenge with Fusciola hepatica metacercariae but not against an intraperitoneal challenge with newly excysted juvenile (NEJ) flukes. The timing of the challenge was important and a double infection with the nematode gave more consistent results than a single. Resistance appeared to be associated with a prior induction of intestinal eosinophilia. Sera from these resistant rats, however, failed to induce eosinophil adherence to NEJ flukes in vitro.     

Killing of newly excysted juveniles of Fasciola hepatica in sensitized rats

Newly excysted juvenile Fasciola hepatica were injected intraperitoneally into previously sensitized rats. They were recovered at various intervals post-injection and examined by light and electron microscopy. The challenge flukes were rapidly coated with peritoneal cells which, in the early stages, were mainly eosinophils. The eosinophils adhered closely to the flukes and degranulated on to their surface releasing cytochemically detectable peroxidase. Vacuoles formed in the tegument of the flukes beneath the adherent eosinophils and these increased in size until they spanned the width of the tegument, thus destroying its continuity. From 4 h post-injection some of the flukes had lost their teguments and were surrounded by phagocytic cells, particularly neutrophils; at this stage they were judged to be dead. During the first five minutes post-injection degranulating mast cells were associated with the challenge flukes. Their role in eosinophil chemotaxis is discussed as are the possible mechanisms of eosinophil adherence and degranulation. Using an anti-C₃ fluorescein conjugate, it was demonstrated that C₃ was not bound to the surface of challenge flukes either in vitro or in vitro in immune serum.     

Molecular differentiation of Turkey cattle isolates of <Emphasis Type="Italic">Fasciola hepatica</Emphasis> and <Emphasis Type="Italic">Fasciola gigantica</Emphasis>

The most common and widespread liver flukes of the genus Fasciola are Fasciola hepatica and F. gigantica. Adults of both species occur in many domestic ruminants and in humans and can cause serious disease. The differential diagnosis of these flukes infection is very important because of their different transmission and epidemiological characteristics. A simple and rapid PCR-restriction fragment length polymorphism (RFLP) assay, using the common restriction enzymes AluI and RsaI, is described to distinguish between both fasciolid species. After the digestion of the mitochondrial cytochrome c oxidase 1 (CO1) PCR product with the restriction enzyme AluI, the RFLP profile obtained from F. hepatica revealed two fragments, whereas F. gigantica was not cut. The RsaI digestion generated two fragments from F. gigantica, whereas it did not cut the PCR product from F. hepatica. Results were confirmed with CO1 sequence analysis of both F. hepatica and F. gigantica. The present study suggests that the PCRRFLP method described here can be used for the proper identification of Fasciola species.     

Fasciola hepatica infection reduces Mycobacterium bovis burden and mycobacterial uptake and suppresses the pro‐inflammatory response

Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has an annual incidence in cattle of 0.5% in the Republic of Ireland and 4.7% in the UK, despite long‐standing eradication programmes being in place. Failure to achieve complete eradication is multifactorial, but the limitations of diagnostic tests are significant complicating factors. Previously, we have demonstrated that Fasciola hepatica infection, highly prevalent in these areas, induced reduced sensitivity of the standard diagnostic tests for BTB in animals co‐infected with F. hepatica and M. bovis. This was accompanied by a reduced M. bovis‐specific Th1 immune response. We hypothesized that these changes in co‐infected animals would be accompanied by enhanced growth of M. bovis. However, we show here that mycobacterial burden in cattle is reduced in animals co‐infected with F. hepatica. Furthermore, we demonstrate a lower mycobacterial recovery and uptake in blood monocyte‐derived macrophages (MDM) from F. hepatica‐infected cattle which is associated with suppression of pro‐inflammatory cytokines and a switch to alternative activation of macrophages. However, the cell surface expression of TLR2 and CD14 in MDM from F. hepatica‐infected cattle is increased. These findings reflecting the bystander effect of helminth‐induced downregulation of pro‐inflammatory responses provide insights to understand host‐pathogen interactions in co‐infection.     

Time-dependent tegumental surface changes in juvenile Fasciola gigantica in response to triclabendazole treatment in goat

Triclabendazole (TCBZ), the anthelmintic drug active against both mature and immature liver flukes, was used to investigate the effect of in vivo treatment on the tegumental surface of juvenile Fasciola gigantica. Five goats were infected with 150 F. gigantica metacercariae each by oral gavage. Four of them were treated with single dose of TCBZ at 10 mg/kg at four weeks post-infection. They were euthanized at 0 (untreated), 24, 48, 72 and 96 h post treatment. Juvenile flukes were manually retrieved from the goat livers and processed for scanning electron microscopy. In control flukes, the anterior region was adorned with sharply pointed spines projecting away from the surface, while in the posterior region, spines become shorter and narrower, loosing serration and with the appearance of distinct furrows and papillae. The dorsal surface retained the same pattern of surface architecture similar to that of ventral surface. Flukes obtained from 24 h post-treatment did not show any apparent change and were still very active. However, there were limited movements and some blebbing, swelling, deposition of tegumental secretions and some flattening displayed by the flukes of 48 h post-treatment. All the worms were found dead 72 h post-treatment and showed advanced level of tegumental disruptions, consisting of severe distortion of spines, sloughing off the tegument to expose the basal lamina, formation of pores and isolated patches of lesions. By 96 h post-treatment, the disruption was extremely severe and the tegument was completely sheared off causing deeper lesions that exposed the underlying musculature. The disruption was more severe at posterior than anterior region and on ventral than dorsal surface. The present study further establishes the time-course of TCBZ action in vivo with 100% efficacy against the juvenile tropical liver fluke.     

Molecular discrimination of eggs of cervid trematodes using the Teflon (PTFE) technique for eggshell disruption

Molecular comparative analysis of eggs of four liver and stomach flukes of cervids and domestic ruminants, Fasciola hepatica, Fascioloides magna, Dicrocoelium dendriticum and Paramphistomum cervi, was performed using a new methodological approach for eggshell disintegration. Eggs of all species were crushed mechanically by the Teflon method (PTFE) without use of chemical reagents and an efficient disruption of eggshell was checked microscopically. The egg suspension was then subjected to DNA isolation and PCR amplification using species-specific primers that annealed to the internal transcribed spacer 2 (ITS2) region of ribosomal DNA. The size of PCR products of individual species corresponded well to the size of amplicons obtained from adult flukes. The results provided evidence that the Teflon method does not destroy the structure of egg DNA, thus making the procedure broadly applicable during coprological examinations. Molecular markers introduced here are particularly important for blanket screening and differentiation of morphologically hardly distinguishable F. hepatica, F. magna and P. cervi eggs.     

Differential expression and localization of saposin-like protein 2 of Fasciola hepatica

FhSAP2 is a novel antigen isolated from the adult fluke of Fasciola hepatica. Based on sequence similarity with amoebapores and other related proteins, it belongs to the saposin-like protein (SAPLIP) family. FhSAP2 has been shown to be highly immunogenic and capable of inducing protective immune responses in mice and rabbits challenged with F. hepatica. Moreover, FhSAP2 is also reactive with sera from humans with chronic fascioliasis. In the present study, we investigated the expression of FhSAP2 in various developmental stages of F. hepatica by qPCR and demonstrated that FhSAP2–mRNA species are up-regulated in undeveloped eggs, newly excysted juveniles, and adults, but down-regulated in the miracidium stage. Monoclonal antibodies against FhSAP2 were produced, and two clones that are positive to F. hepatica whole-body extract, but not reactive with extracts from other trematodes, were selected, expanded and used for histolocalization studies. Confocal immunofluorescence revealed the presence of native FhSAP2 in epithelial cells surrounding the gut, toward the outermost part of the tegument, and toward the tegumental cells of both adults and newly excysted juveniles.     

Lack of protective efficacy in buffaloes vaccinated with Fasciola gigantica leucine aminopeptidase and peroxiredoxin recombinant proteins

Gene coding for leucine aminopeptidase (LAP), a metalloprotease, was identified in the tropical liver fluke, Fasciola gigantica; that on sequence analysis showed a close homology (98.6%) with leucine aminopeptidase of the temperate liver fluke, Fasciola hepatica. The recombinant leucine aminopeptidase protein was expressed in Escherichia coli. F. gigantica peroxiredoxin, a hydrogen peroxide scavenger and an immunomodulating protein, was also cloned and expressed in E. coli. A vaccination trial in buffaloes was conducted with these two recombinant proteins, with 150 and 300 μg of leucine aminopeptidase and a cocktail of 150 μg each of recombinant leucine aminopeptidase and peroxiredoxin in three groups, respectively. Both Th1- and Th2-associated humoral immune responses were elicited to immunization with these antigens. A challenge study with 400 metacercariae did not show a significant protection in terms of reduction in the worm burden (8.4%) or anti-fecundity/embryonation effect in the immunized groups, as to the non-immunized control animals. Our observations in this buffalo vaccination trial are contrary to the earlier promise shown by leucine aminopeptidase of F. hepatica as a leading candidate vaccine molecule. Identification of leucine aminopeptidase gene and evaluation of the protein for its protective efficacy in buffaloes is the first scientific report on this protein in F. gigantica.     

Anthelmintic activity of benzimidazole derivatives against Toxocara canis second-stage larvae and Hymenolepis nana adults

The anthelmintic activity of 11 benzimidazole derivatives (A1-A11) and 2 thioureides N,N′-disubstituted (B1-B2) was determined. Each compound and albendazole was tested in vitro against Toxocara canis larvae and in vivo against Hymenolepis nana adult. Compounds A1-A6 and B1-B2 were designed as albendazole prodrugs. Compounds A8-A11 were designed as direct analogues of A7, which had previously proved to be an effective agent against Fasciola hepatica. Results of the in vitro screening showed that A6 was more active than albendazole at 0.18 μM (relative mobility 40% and 80%, respectively). Whereas that the in vivo evaluation against H. nana, compounds A7-A11 demonstrated significant activity in terms of removing cestode adults in the range of 88-97%, displaying better efficacy than albendazole (83%).     

Determination of ribosomal internal transcribed spacer 2 (ITS2) interspecific markers in <Emphasis Type="Italic">Fasciola hepatica,Fascioloides magna,Dicrocoelium dendriticum</Emphasis> and <Emphasis Type="Italic">Paramphistomum cervi</Emphasis> (Trematoda), parasites of wild and domestic ruminants

The species-specific ribosomal internal transcribed spacer 2 (ITS2) markers were designed for PCR-based molecular differentiation of Fasciola hepatica, Fascioloides magna, Dicrocoelium dendriticum and Paramphistomum cervi, liver and stomach flukes of domestic and free living ruminants. Complete ITS2 sequences were obtained for D. dendriticum and P. cervi, for the later species, ITS2 structure was determined for the first time. Intraspecific variation within geographically distant populations was found to be either very low (F. hepatica; D. dendriticum) or even absent (F. magna; P. cervi). ITS2 regions with the absence of intraspecific polymorphisms but with interspecific sequence heterogeneity were applied for design of speciesspecific primers. The specificity of developed primers was tested on genomic DNA isolated from adult individuals of studied fluke species. Application of the primers is of particular value for molecular differentiation of morphologically hardly distinguishable F. hepatica, F. magna and P. cervi eggs after coprological examinations.     

Efficacy of Synriam™, a new antimalarial combination of OZ277 and piperaquine,against different developmental stages of Schistosoma mansoni

Control of schistosomiasis relies on a single drug, praziquantel (PZQ). Given the rising concerns about the potential emergence of PZQ-resistant strains, it has now become necessary to search for novel therapeutics. However, the current pace for anti-schistosomal drug discovery is slow; hence, repositioning of existing approved drugs can offer a safe, rapid and cost-effective solution. The anti-malarial synthetic artemisinin-derivatives trioxolanes demonstrated anti-schistosomal efficacies against the three major species infecting humans and, unlike PZQ, showed activities against both juvenile and adult worm stages. The 1,2,4-trioxolane/OZ277 (arterolane maleate) in combination with a partner drug: piperaquine phosphate was recently developed as an anti-malarial drug and manufactured by Ranbaxy (India) as Synriam™ (SYN). Herein, the in vivo activities of SYN were investigated in a mouse model of Schistosoma mansoni (S. mansoni), compared to PZQ. We show that a single fixed dose of 240 mg/kg SYN (40 mg/kg arterolane and 200 mg/kg piperaqine) induced significant protective effects in mice, in terms of reduction in worm and tissue egg burdens, which were evident against all schistosome developmental stages. Extensive alterations in the tegument and subtegumental tissues of SYN-exposed worms were revealed by both scanning and transmission electron microscopes. Progressive decrease in worm activity and occurrence of death were noticed in vitro upon exposure to the drug − more pronounced in the presence of haemin. This report provides the first evidence of the efficacy of a combination of 1,2,4-trioxolane and piperaquine against S. mansoni in mice. Being effective against young stages, SYN could be used to prevent early Schistosoma infection.     

In vivo activity of perifosine against Leishmania amazonensis

Miltefosine has been established as the first oral administration drug against cutaneous and visceral leishmaniasis. Other alkyl-phospholipids such as edelfosine have been tested against Leishmania showing an in vitro antiparasitic activity. Perifosine in vitro activity has been previously demonstrated against different Leishmania species including Leishmania amazonensis. In this study edelfosine and perifosine were orally administered to BALB/c mice at doses of 1 and 2.5 mg/kg/day during 28 days and 5 mg/kg/day during 14 days, starting the treatment 2 weeks after the first treatment scheme. Lesion sizes and parasitic burden as well as viability were determined in order to establish the treatment effectiveness. An assay to compare miltefosine at standard dose of 2.5 mg/kg/day during 28 days to an in vivo treatment with perifosine at the most effective treatment scheme observed in this study 5 mg/kg/day during 14 days, was also developed. Perifosine showed the higher activity in the in vivo assay and is showing as a new possibility within the alkyl-phospholipids group for the treatment against cutaneous leishmaniasis caused by L. amazonensis.     

Neutralization of the activity of a Fasciola hepatica cathepsin L proteinase by anti-cathepsin L antibodies

Fasciola hepatica secretes a cathepsin L proteinase that is suggested to play an in vivo role in immunoprotection since the enzyme can cleave host immunoglobulin. In the present report, rabbit anti-cathepsin L IgG was shown to bind to the cathepsin L enzyme and inhibit its ability to cleave IgG molecules. Cathepsin L can prevent the antibody-mediated attachment of eosinophils to newly excysted juveniles in in vitro assays; however, if anti-cathepsin L IgG are mixed with the cathepsin L prior to the addition of the enzyme to the assay, eosinophils attach to the newly excysted juveniles. Thus it is possible to prepare antibodies that can bind and disrupt the biological activity of the F. hepatica cathepsin L.     

Resistance to liver fluke infection in the natural sheep host is correlated with a type-1 cytokine response

Indonesian thin‐tail (ITT) sheep can resist infection with Fasciola gigantica but not F. hepatica and presents an ideal model to investigate the mechanisms of liver fluke resistance in a natural host. This study examines the local and systemic immune responses of sheep during Fasciola infection and demonstrates that different anatomical tissues display distinct cytokine profiles consistent with liver fluke migration. The study also reveals a significant difference in the cytokine and antibody profiles of ITT sheep infected with F. gigantica compared with F. hepatica, with a higher ratio of IL‐4/IFN‐γ mRNA expression and specific IgG1/IgG2 antibodies strongly correlating with pathology. Interestingly, the significant type‐1 cytokine profile occurred in the lymph node closest to the site of infection at a time when the effective immune response against F. gigantica liver flukes is thought to occur. When the same F. gigantica infection in the resistant ITT sheep was compared with the susceptible Merino breed, the resistant type‐1 phenotype against liver fluke infection was only observed in the ITT sheep. These studies provide the first evidence to suggest that the induction of an early type‐1 immune response in this natural sheep host may be responsible for the ability to resist liver fluke infection.     

达托霉素对2679株革兰阳性球菌外抗菌活性的研究

目的 研究达托霉素等抗菌药物对2679株革兰阳球菌的体外抗菌活性.方法 收集2010年1月-2011年12月9个城市17家教学医院临床分离的2679株非重复革兰阳性球菌.采用微量肉汤稀释法测定的达托霉素最低抑菌浓度(MIC),用琼脂稀释法测定其他抗菌药物的MIC值,用WHONET5.6软件进行药敏数据统计分析.结果 耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRSCoN)检出率分别为45.8％和84.2％,MRSA对复方磺胺甲(噁)唑和氯霉素的敏感率分别为93.1％和85.5％,对红霉素、四环素、克林霉素和利福平的敏感率分别为13.8％、26.6％、63.2％、50.0％,对达托霉素、万古霉素和利奈唑胺的敏感率均为100.0％,MRSCoN对达托霉素、万古霉素和利奈唑胺的敏感率均为100.0％,达托霉素对于MRSA和MRSCoN的MIC50和MIC90均为0.5 mg/L.513株肠球菌对于高水平庆大霉素耐药率为56.9％,氯霉素和四环素的敏感率分别为76.0％和44.1％,对替加环素和达托霉素敏感率均达100.0％,达托霉素对于其中17株耐万古霉素肠球菌(V RE)的MIC50和MIC90均为2 mg/L.肺炎链球菌和β-溶血链球菌对于达托霉素的敏感率均为100.0％,按口服青霉素折点判读,青霉素不敏感的肺炎链球菌(PNSSP)的比例为63.1％.达托霉素对于PNSSP的MIC50和MIC90分别是0.125 mg/L和0.25 mg/L.达托霉素对于β-溶血链球菌MIC50和MIC90分别是0.008 mg/L和0.032 mg/L.结论 达托霉素对临床常见革兰阳性球菌具有较好的抗菌活性,包括多重耐药菌,是治疗革兰阳性菌特别是耐药菌感染的很好选择.     

In vitro antimalarial interactions between mefloquine and cytochrome P450 inhibitors

The treatment and control of malaria is becoming increasingly difficult due to resistance of Plasmodium falciparum strains resistance to commonly used antimalarials. Combination therapy is currently the strategy for combating multi-drug resistant falciparum malaria, through exploiting phamacodynamic synergistic effect and delaying the emergence of drug resistance. The objective of the present study was to investigate antimalarial activity of inhibitors of cytochrome P450 (CYP) enzyme including their interactions with the antimalarial mefloquine against chloroquine-resistant (K1) and chloroquine-sensitive (3D7) P. falciparum clones in vitro. Results showed IC₅₀ (drug concentration which produces 50% schizont maturation inhibition) values [mean (range)] of mefloquine against K1 and 3D7 clones to be 8.6 (8.0–9.3) and 12.1 (10.5–13.8) nM, respectively. The corresponding values for the IC₅₀ of quinidine were 32.2 (31.9–32.5) and 28.7 (28.4–29.0) nM, and for ketoconazole were 3.9 (3.7–4.1) and 4.8 (4.6–5.1) μM, respectively. Analysis of isobologram revealed a trend of decreasing of fraction IC₅₀ (FIC), which indicates synergistics of the either quinidine or ketoconazole with mefloquine for both chloroquine-resistant and chloroquine-sensitive clones.     

Activity of DSA against anaerobically adapted Mycobacterium bovis BCG in vitro

DSA is a β-sulfonylacetamide with in vitro activity against pathogenic mycobacteria. Although the enzymatic target(s) of DSA has not been identified, studies to date suggest that this class of compounds may interfere directly or indirectly with ATP synthase and other components of the mycobacterial respiratory chain. In this study we further evaluated the in vitro activity of DSA against anaerobically adapted BCG using two established models. DSA killed BCG in the anaerobic Wayne model. Bactericidal activity ranged from >99% to 60%. DSA killed rifampin-tolerant persisters with a reduction in viable counts of 1.5 log₁₀ versus controls. Conclusive identification of the DSA-specific target(s) will permit a better understanding of the unique mechanism of action of this class of compounds against both aerobically growing and anaerobically adapted bacilli in vitro.     

Fluke egg characteristics for the diagnosis of human and animal fascioliasis by Fasciola hepatica and F. gigantica

In trematodiases, shape and size of the fluke eggs shed with faeces are crucial diagnostic features because of their typically reduced intraspecific variability. In fascioliasis, the usual diagnosis during the biliary stage of infection is based on the classification of eggs found in stools, duodenal contents or bile. The aim of the present study is to validate the identification of Fasciola species based on the shape and size of eggs shed by humans, characterizing their morphometric traits using a computer image analysis system (CIAS). The influence of both the geographical location and of the host (human and livestock) has been analysed. Coprological studies were carried out in fascioliasis human endemic areas, where only F. hepatica is present (the northern Bolivian Altiplano and the Cajamarca valley in Peru), and where F. hepatica and F. gigantica coexist (the Kutaisi region of Georgia, the Nile Delta in Egypt, and the Quy Nhon province in Vietnam). Classically, it is considered that at the abopercular end of the shell of Fasciola eggs there is often a roughened or irregular area. Nevertheless, results show that the frequency of the presence of this feature in F. hepatica is population-dependent, and therefore is not a pathognomonic criterion in diagnosis. The study reveals that eggs shed by humans show morphological traits different from eggs shed by animals. In humans, F. hepatica eggs are bigger and F. gigantica eggs are smaller than reported to date from livestock, and their measurements overlap when compared. The material analysed in this study shows that the size of eggs shed by humans from Georgia and Egypt corresponds to the F. hepatica morph, while the size of eggs shed by humans from Vietnam corresponds to the F. gigantica morph. Measurements of F. hepatica and F. gigantica eggs originating from humans and animals from sympatric areas overlap, and, therefore, they do not allow differential diagnosis when within this overlapping range. In this sense, the new results should aid clinicians since the application of the classic egg size range in human samples may lead to erroneous conclusions. Fasciolid egg size in human stool samples ought to be corrected in books and monographs related to medical parasitology and/or tropical medicine as well as in guides for clinicians and parasitic disease diagnosis analysts.     

Larvicidal activity of synthesized silver nanoparticles using Eclipta prostrata leaf extract against filariasis and malaria vectors

Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of synthesized natural products for vector control have been a priority in this area. In this study, larvicidal activity of synthesized silver nanoparticles (AgNPs) utilizing aqueous extract from Eclipta prostrata, a member of the Asteraceae was investigated against fourth instar larvae of filariasis vector, Culex quinquefasciatus say and malaria vector, Anopheles subpictus Grassi (Diptera: Culicidae). The synthesized AgNPs characterized by UV–vis spectrum, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). SEM analyses of the synthesized AgNPs were clearly distinguishable measured 35–60 nm in size. Larvae were exposed to varying concentrations of aqueous extract of synthesized AgNPs for 24 h. The maximum efficacy was observed in crude aqueous, and synthesized AgNPs against C. quinquefasciatus (LC₅₀ = 27.49 and 4.56 mg/L; LC₉₀ = 70.38 and 13.14 mg/L), and against A. subpictus (LC₅₀ = 27.85 and 5.14 mg/L; LC₉₀ = 71.45 and 25.68 mg/L) respectively. The chi-square value were significant at p < 0.05 level. These results suggest that the synthesized AgNPs have the potential to be used as an ideal eco-friendly approach for the control of the Culex tritaeniorhynchus and A. subpictus. This method is considered as a new approach to control vectors. Therefore, this study provides first report on the mosquito larvicidal activity of synthesized AgNPs against vectors.