ABSTRACT
Background & objectives: Sand fly saliva contains proteins that modulate the host immune system and it plays an important role in both blood feeding and the outcome of Leishmania infections. The profile of the salivary proteins was examined and analyzed from an endemic focus of zoonotic cutaneous leishmaniasis by wild P. papatasi to find local and suitable antigens as potential proteins for developing Leishmania vaccine alongside the development of a new extraction technique. Methods: Specimens were caught from Bojnord, using funnel and CDC traps. Different methods of protein extraction were employed and a new technique was developed. The proteins were extracted from the salivary glands tissues with a lysis buffer. Purification was performed using RP-HPLC, with a linear gradient protocol from 0-60 % of acetonitrile. PpSP15 was characterized by SDS-PAGE. Results: The concentration of extracted protein content was 0.5 and 0.03 ?g/?l in chemical and physical methods, respectively. PpSP15 was isolated at a weight of 15kDa in 80–85 min of run time. SDS-PAGE was able to characterize PpSP15. The crude extract of the chemical method, revealed 15 separated bands, ranging from 11–100 KDa. Tajima D index was positive. Interpretation & conclusion: PpSP15 was characterized from Iranian specimens; it is a very highly hydrophobic protein of salivary glands among SP15- like proteins. The chemical method of extraction was found to be more effective than physical methods (P < 0.05). For developing a vaccine against leishmaniasis, depending on the location, choosing suitable proteins should be considered and an efficient extraction method should be used.
ABSTRACT
Objective: To investigate and predict the effects of climate change on the potential distribution of the main vector and reservoir hosts of the disease in Yazd province in the future. Methods: Distribution data for vector and reservoir hosts of zoonotic cutaneous leishmaniasis in Yazd province were obtained from earlier studies conducted in the area. MaxEnt ecological niche modeling was used to predict environmental suitability. BCC-CSM1-1(m) model and two climate change scenarios, RCP 4.5 and RCP 8.5 were used for horizons 2030 and 2050 climate projections. Future projections were based on data of a regional climate change model. Results: With both scenarios in 2030 and 2050, the results of jackknife test indicated that the mean temperature of wettest quarter and temperature annual range had the greatest effect on the model for the vector and the reservoir hosts, respectively. Conclusions: The climate conditions are the major determinants of zoonotic cutaneous leishmaniasis incidence rate in Yazd Province. These climate conditions provide favorable habitats for ease transmission of zoonotic cutaneous leishmaniasis in this endemic area. Habitats suitability for the vector and reservoir will be expanding in the coming years compared with the current conditions, such that, in horizon 2030 & 2050, the probability of the presence of the vector and reservoir within 38 580 and 37 949 km2, respectively, from Yazd province is above 60%. Moreover, an increase is predicted in the presence of the vector in the western parts and the reservoir in the northern and central parts of the province in the future. Understanding the role of environmental and bioclimatic factors in zoonotic cutaneous leishmaniasis occurrence can provide a guide for policy-makers in the creation and implementation of more effective policies for prevention and control.
ABSTRACT
Objective: To investigate and predict the effects of climate change on the potential distribution of the main vector and reservoir hosts of the disease in Yazd province in the future. Methods: Distribution data for vector and reservoir hosts of zoonotic cutaneous leishmaniasis in Yazd province were obtained from earlier studies conducted in the area. MaxEnt ecological niche modeling was used to predict environmental suitability. BCC-CSM1-1(m) model and two climate change scenarios, RCP 4.5 and RCP 8.5 were used for horizons 2030 and 2050 climate projections. Future projections were based on data of a regional climate change model. Results: With both scenarios in 2030 and 2050, the results of jackknife test indicated that the mean temperature of wettest quarter and temperature annual range had the greatest effect on the model for the vector and the reservoir hosts, respectively. Conclusions: The climate conditions are the major determinants of zoonotic cutaneous leishmaniasis incidence rate in Yazd Province. These climate conditions provide favorable habitats for ease transmission of zoonotic cutaneous leishmaniasis in this endemic area. Habitats suitability for the vector and reservoir will be expanding in the coming years compared with the current conditions, such that, in horizon 2030 & 2050, the probability of the presence of the vector and reservoir within 38 580 and 37 949 km
ABSTRACT
BACKGROUND Leishmania major is an Old World species causing cutaneous leishmaniasis and is transmitted by Phlebotomus papatasi and Phlebotomus duboscqi. In Brazil, two isolates from patients who never left the country were characterised as L. major-like (BH49 and BH121). Using molecular techniques, these isolates were indistinguishable from the L. major reference strain (FV1). OBJECTIVES We evaluated the lipophosphoglycans (LPGs) of the strains and their behaviour in Old and New World sand fly vectors. METHODS LPGs were purified, and repeat units were qualitatively evaluated by immunoblotting. Experimental in vivo infection with L. major-like strains was performed in Lutzomyia longipalpis (New World, permissive vector) and Ph. papatasi (Old World, restrictive or specific vector). FINDINGS The LPGs of both strains were devoid of arabinosylated side chains, whereas the LPG of strain BH49 was more galactosylated than that of strain BH121. All strains with different levels of galactosylation in their LPGs were able to infect both vectors, exhibiting colonisation of the stomodeal valve and metacyclogenesis. The BH121 strain (less galactosylated) exhibited lower infection intensity compared to BH49 and FV1 in both vectors. MAIN CONCLUSIONS Intraspecific variation in the LPG of L. major-like strains occur, and the different galactosylation levels affected interactions with the invertebrate host.
Subject(s)
Humans , Leishmania major , Lysosomal Membrane Proteins , Psychodidae , Host-Parasite InteractionsABSTRACT
Chandipura virus (CHPV) (Vesiculovirus: Rhabdoviridae) garnered global attention as an emerging neurotropic pathogen inflicting high mortality in children within 24 h of commencement of symptoms. The 2003-2004 outbreaks in Central India witnessed case fatality rates ranging from 56-75 per cent in Andhra Pradesh and Gujarat with typical encephalitic symptoms. Due to the acute sickness and rapid deterioration, the precise mechanism of action of the virus is still unknown. Recent studies have shown increased expression of CHPV phosphoprotein upto 6 h post infection (PI) demonstrating CHPV replication in neuronal cells and the rapid destruction of the cells by apoptosis shed light on the probable mechanism of rapid death in children. Phlebotomine sandflies are implicated as vectors due to their predominance in endemic areas, repeated virus isolations and their ability to transmit the virus by transovarial and venereal routes. Significant contributions have been made in the development of diagnostics and prophylactics, vaccines and antivirals. Two candidate vaccines, viz. a recombinant vaccine and a killed vaccine and siRNAs targeting P and M proteins have been developed and are awaiting clinical trials. Rhabdomyosarcoma and Phlebotomus papatasi cell lines as well as embryonated chicken eggs have been found useful in virus isolation and propagation. Despite these advancements, CHPV has been a major concern in Central India and warrants immediate attention from virologists, neurologists, paediatricians and the government for containing the virus.
ABSTRACT
Background & objectives: In Egypt, Phlebotomus papatasi is the main vector of cutaneous leishmaniasis. In nature, P. papatasi feeds on blood from different hosts and sucrose (other sugars) mainly from fig fruits. The aim of this study was to examine the effects of three food regimes on the life table parameters of females mainly the life expectancy as a factor determining the fly’s capability for Leishmania transmission. Methods: Females maintained on different diets (30% sucrose solution, Guinea pig blood and sucrose followed by blood) under laboratory conditions were observed for offspring emergence to examine the survival period expressed as the median emergence time (E50) and female fecundity (females/female). Life table was constructed including the mean life expectancy at emergence (e0) as a measure of longevity and the mortality rate per day (qx). Results: Females fed on sucrose-blood has the highest fecundity and the shortest E50 compared to those fed on other diets. The mean life expectancy at emergence (e0) differed significantly with the highest value being for females fed on sucrose. Interpretation & conclusion: The calculated expectancies for female life beyond the infective age (8 days) indicated that more flies would survive to become infective when fed on sucrose-blood meals than those offered blood alone which increases its capability for Leishmania transmission.
ABSTRACT
Background & objectives: Since not much information on Chandipura virus is available, an attempt was made to study the growth kinetics of the virus in certain vertebrate, invertebrate cell lines and embryonated chicken eggs. Methods: Comparative study of Chandipura virus (CHPV) growth kinetics in three vertebrate cell lines [Vero E6, Rhabdo myosarcoma (RD), Porcine stable kidney (PS) cell lines], two insect cell lines [Aedes aegypti (AA) and Phlebotomus papatasi (PP-9) cell lines] and embryonated pathogen free chicken eggs was conducted, by tissue culture infective dose 50 per cent (TCID50) and indirect immunofluorescence assay (IFA). Results: All the cell lines and embryonated egg supported the growth of CHPV and yielded high virus titre. The vertebrate cell lines showed distinct cytopathic effect (CPE) within 4-6 h post infection (PI), while no CPE was observed in insect cell lines. PP-9 cell line was the most sensitive system to CHPV as viral antigen could be detected at 1 h PI by IFA. Interpretation & conclusions: Our results demonstrated that all the systems were susceptible to CHPV and achieved high yield of virus. However, the PP-9 cell line had an edge over the others due to its high sensitivity to the virus which might be useful for detection and isolation of the virus during epidemics.