Effect of temperature stress on immature stages and susceptibility of Aedes aegypti mosquitoes to chikungunya virus

A high temperature stress of 44.5°C for 10 minutes on the larval stages was found to affect the susceptibility of adult Aedes aegypti mosquitoes to chikungunya virus. At this temperature, the mortality of the mosquito larvae was found to be approximately 95%, whereas a temperature greater than 45°C for 10 minutes was found to be lethal. A temperature tolerant (TT) strain was developed by exposing the larvae to a temperature of 44.5°C for 10 minutes at every generation for five generations. This strain was established to determine whether increase in the susceptibility was due to any selection pressure of higher temperature or to the influence of other intrinsic factors such as expression of immunoresponsive (IR) genes. Other studies on these mosquito strains showed that when maintained at 28 ± 1°C, there was no difference in the larval duration and mortality in the immature stages, but the mean survival of female mosquitoes in the TT strain was 5-6 days longer. Conversely, when mosquitoes were maintained throughout at 37°C the mean survival of the mosquitoes decreased drastically in both strains, but the mean survival of females in the TT strain was 5-6 days longer compared with the unstressed controls. This increases the probability of at least one more blood meal. Fecundity of the TT strain was found to be lower than that of the control mosquitoes. Data suggest that expression of certain IR genes was affected by the heat shock. Some of these genes were up-regulated and down-regulated, which may have affected the susceptibility of mosquitoes to the virus. Although there was some selection in the temperature-tolerant individuals in the TT strain, when stressed by heat they showed expression of IR genes in a pattern similar to that in the normal controls. It appears that an increase in temperature above the average temperature of an area might help increase the proportion of virus-susceptible mosquitoes in the population. Such an increase in temperature in an endemic area would not only enhance the selection of temperature-tolerant individuals in a population having more longevity, but would also affect both intrinsic and extrinsic factors by reducing the extrinsic incubation period and increasing susceptibility of mosquitoes to viruses due to affected expression of IR genes

IDENTIFICATION OF POTENTIAL INHIBITORS FOR LOWERING CHOLESTEROL LEVEL BY INHIBITING PCSK9

ABSTRACTObjective: PCSK9 has medical significance in lowering cholesterol levels. Inhibitors target and inactivate PCSK9 in the liver. Knocking out PCSK9 (proprotein convertase subtilisin kexin 9) reduces the amount of harmful LDL cholesterol circulating in the bloodstream. There are two known inhibitors for treating the cardiovascular disease Arilocumab†and Evalocumabâ€. However there are many side-effects. The current study is to identify natural and synthetic inhibitor using the pharmacophoric feature of the known inhibitor and validating the short listed candidates using Molecular dynamics and ADMET properties.Methods: Known inhibitors for the PCSK9 Protein were taken from the BINDING DATABASE. Molecular docking was performed for the known inhibitors with the PCSK9 protein. After docking the best inhibitor was selected and the docking result was then imported to find the pharmacophoric features.Results: The pharmacophore model was generated with 3 features containing  1 hydrogen bond acceptor(A),1 Hydrogen bond donor(B) and 1 Aromatic ring. The constructed e-pharmacophore model was screened with more than 20000 natural compounds. 5 compounds were short listed. Among them ZINC85625485 has  glide  score  of  -13.03  kcal/mol  with  glide  energy  was  -57.62 kcal/mol and ZINC85625406 has glide score of -8.1kcal/mol with glide energy was -39.33kcal/mol were taken as the best Hits.Conclusion: PCSK9 is known to be a therapeutic agent as it controls the plasma LDL cholesterol levels by posttranslational regulation of the LDL receptor. Therefore, up-regulation of PCSk9 can lead to elevated cholesterol level in such case inhibition of PCSK9 will be a effective remedy. In this study already known inhibitors were taken and pharmacophore feature was generated. Zinc database was screened to find out novel compounds with similar pharmacophore features that can act as potentially active compound against PCSK9. ZINC85625485 and ZINC85625406 were short listed as lead compounds with Molecular dynamics simulation and checking the ADMET properties. Keywords: PCSK9, Docking, ADMET, Molecular Dynamics.                                                            Â

To evaluate diagnostic efficacy of maternal serum C - reactive protein to predict preterm labour

Background: Preterm birth is a major challenges faced by obstetricians worldwide. Globally, an estimated 13 million babies are born before 37 completed weeks of gestation annually. Preterm birth is the leading direct cause of neonatal death (27%); more than one million preterm newborns die annually. According to report ‘India is among the top 10 countries that account for 60 per cent of the world’s preterm births. Methods to detect preterm labour early include ultrasound examination of the cervix and detection of biochemical markers of preterm labour in blood (include serum C - reactive protein level) and cervicovaginal secretions. The objective of the study was evaluate diagnostic efficacy of maternal serum C - reactive protein (CRP) to predict preterm labour.Methods: A prospective study comprised of a total of 132 pregnant women with singleton fetus with symptoms of preterm labour. Serum CRP values was taken in all patients. Out of which 17 patients were lost during follow up, 3 patients develop PPROM. Hence study was conducted over 112 patients. Among these 62 patients went in preterm labour and 50 patients delivered at term.Results: For predicting preterm delivery sensitivity, specificity, positive and negative predictive value for serum CRP were 70.9%, 70%, 74.5% and 66% respectively.Conclusions: Serum CRP is good predictor to differentiate the women who were likely to deliver preterm. CRP positivity in early pregnancy is associated with nearly a twofold increased risk of preterm delivery

Identification of New Bioactive Compounds by Gc-Ms and Estimation of Physiological and Biological Activity of Kala Dhaman (Cenchrus setigerus)

ABSTRACT The present study was carried out to determine the possible bioactive components (sterols) in acetone extracts of Cenchrus setigerus using GC-MS analysis and in-vivo estimation of nitrogen assimilatory enzymes (NR, ALT, AST, GS, GDH and GOGAT) of seedlings and antibiotic activity of root extracts in various polar solvents of Cenchrus setigerus were done and antibiotic activity was tested against the G-ve bacteria including Proteus merabilis, Klebsiella pnemoniae, Agerobacterium tumefaciens and one fungi Aspergillus niger using disk diffusion method followed by determination of minimum inhibitory concentrations (MIC) by broth dilution method, against sensitive bacteria. Results reveal that various steroids from the above said plant were identified. The prevailing compounds (sterols) in the acetone extract of C. setigerus were 9,19-Cycloergost-24(28)-en-3-ol, 4,14-dimethyl-, acetate, (3β, 4α, 5α)-(14.39%), 2-Hexadecen-1-ol, 3,7, 11,15-tetramethyl-, [R-[R*,R*-(E)]]-(phytol) (1.27%), Cholest-4-en-3-one (2.36%) and β-Tocopherol (2.07%). All nitrogen assimilatory enzymes, GS showed highest activity followed by NR and highest antibiotic activity was exhibited by the isopropyl alcohol and chloroform extract against P. merabilis and K. pnemoniae after the GAA extract, The Glacial acetic acid extract was the most active, showing maximum Zone of inhibition (antibacterial effects) and A. tumefaciens (plant pathogen) was more sensitive to the extracts. Gentamycin and ketoconazole, the standard antibiotics were used to inhibiting these bacteria and fungi

Generation, annotation, and analysis of ESTs from midgut tissue of adult female Anopheles stephensi mosquitoes

<p>Abstract</p> <p>Background</p> <p>Malaria is a tropical disease caused by protozoan parasite, <it>Plasmodium</it>, which is transmitted to humans by various species of female anopheline mosquitoes. <it>Anopheles stephensi </it>is one such major malaria vector in urban parts of the Indian subcontinent. Unlike <it>Anopheles gambiae</it>, an African malaria vector, transcriptome of <it>A. stephensi </it>midgut tissue is less explored. We have therefore carried out generation, annotation, and analysis of expressed sequence tags from sugar-fed and <it>Plasmodium yoelii </it>infected blood-fed (post 24 h) adult female <it>A. stephensi </it>midgut tissue.</p> <p>Results</p> <p>We obtained 7061 and 8306 ESTs from the sugar-fed and <it>P. yoelii </it>infected mosquito midgut tissue libraries, respectively. ESTs from the combined dataset formed 1319 contigs and 2627 singlets, totaling to 3946 unique transcripts. Putative functions were assigned to 1615 (40.9%) transcripts using BLASTX against UniProtKB database. Amongst unannotated transcripts, we identified 1513 putative novel transcripts and 818 potential untranslated regions (UTRs). Statistical comparison of annotated and unannotated ESTs from the two libraries identified 119 differentially regulated genes. Out of 3946 unique transcripts, only 1387 transcripts were mapped on the <it>A. gambiae </it>genome. These also included 189 novel transcripts, which were mapped to the unannotated regions of the genome. The EST data is available as ESTDB at <url>http://mycompdb.bioinfo-portal.cdac.in/cgi-bin/est/index.cgi</url>.</p> <p>Conclusion</p> <p>3946 unique transcripts were successfully identified from the adult female <it>A. stephensi </it>midgut tissue. These data can be used for microarray development for better understanding of vector-parasite relationship and to study differences or similarities with other malaria vectors. Mapping of putative novel transcripts from <it>A. stephensi </it>on the <it>A. gambiae </it>genome proved fruitful in identification and annotation of several genes. Failure of some novel transcripts to map on the <it>A. gambiae </it>genome indicates existence of substantial genomic dissimilarities between these two potent malaria vectors.</p

Reciprocal Tripartite Interactions between the Aedes aegypti Midgut Microbiota, Innate Immune System and Dengue Virus Influences Vector Competence

Dengue virus is one of the most important arboviral pathogens and the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. It is transmitted between humans by the mosquitoes Aedes aegypti and Aedes albopictus, and at least 2.5 billion people are at daily risk of infection. During their lifecycle, mosquitoes are exposed to a variety of microbes, some of which are needed for their successful development into adulthood. However, recent studies have suggested that the adult mosquito's midgut microflora is critical in influencing the transmission of human pathogens. In this study we assessed the reciprocal interactions between the mosquito's midgut microbiota and dengue virus infection that are, to a large extent, mediated by the mosquito's innate immune system. We observed a marked decrease in susceptibility to dengue virus infection when mosquitoes harbored certain field-derived bacterial isolates in their midgut. Transcript abundance analysis of selected antimicrobial peptide genes suggested that the mosquito's microbiota elicits a basal immune activity that appears to act against dengue virus infection. Conversely, the elicitation of the mosquito immune response by dengue virus infection itself influences the microbial load of the mosquito midgut. In sum, we show that the mosquito's microbiota influences dengue virus infection of the mosquito, which in turn activates its antibacterial responses

Infection of Anopheles gambiae mosquitoes with entomopathogenic fungi: effect of host age and blood-feeding status

Physiological characteristics of insects can influence their susceptibility to fungal infection of which age and nutritional status are among the most important. An understanding of host–pathogen interaction with respect to these physiological characteristics of the host is essential if we are to develop fungal formulations capable of reducing malaria transmission under field conditions. Here, two independent bioassays were conducted to study the effect of age and blood-feeding status on fungal infection and survival of Anopheles gambiae s.s. Giles. Mosquitoes were exposed to 2 × 1010 conidia m−2 of oil-formulated Metarhizium anisopliae ICIPE-30 and of Beauveria bassiana I93-825, respectively, and their survival was monitored daily. Three age groups of mosquitoes were exposed, 2–4, 5–8, and 9–12 days since emergence. Five groups of different feeding status were exposed: non-blood-fed, 3, 12, 36, and 72 h post-blood feeding. Fungal infection reduced the survival of mosquitoes regardless of their age and blood-feeding status. Although older mosquitoes died relatively earlier than younger ones, age did not tend to affect mosquito susceptibility to fungal infection. Non-blood-fed mosquitoes were more susceptible to fungus infection compared to all categories of blood-fed mosquitoes, except for those exposed to B. bassiana 72 h post-blood feeding. In conclusion, formulations of M. anisopliae and B. bassiana can equally affect mosquitoes of different age classes, with them being relatively more susceptible to fungus infection when non-blood-fed