The Metabolomic Profiles of Sera of Mice Infected with Plasmodium berghei and Treated by Effective Fraction of Naja naja oxiana Using 1H Nuclear Magnetic Resonance Spectroscopy

BACKGROUND

The use of venom fractions from the Iranian cobra could be useful adjunct treatments of malaria with chloroquine. A metabolomic investigation with ¹HNMR spectroscopy was conducted on an effective fraction tested earlier using Plasmodium berghei as an experimental murine model.

PURPOSE

We sought to ascertain both safety and anti-parasitic effects of experimental therapies.

METHODS

After purification of the venom fractions, 25 mice were infected, then treated for 4 days with 0.2 ml of 5 mg/kg, 2.5 mg/kg and 1 mg/kg of the effective fraction, chloroquine, and a drug vehicle. An ED50 was obtained using Giemsa staining and real-time PCR analysis. The toxicity tests inspecting both liver and kidney tissues were performed.

RESULTS

A clear inhibitory effect on parasitaemia was observed (with 75% inhibition with 5 mg/kg and 50% reduction when 2.5 mg/kg dosage used). ED50 obtained 2.5 mg/kg. The metabolomics were identified as differentiation of aminoacyl-t-RNA biosynthesis, valine, leucine, isoleucine biosynthesis and degradation pathways were observed.

CONCLUSION

Upon therapeutic effects of cobra venom fraction, further optimization of dose-dependent response of pharmacokinetics would be worthwhile for further exploration in adjunct experimental venom therapies.

Epidemiology of malaria in East Azerbaijan province, Iran, from 2001 to 2013

Malaria is one of the most important parasitic diseases worldwide, which is characterized by high morbidity and mortality in tropical and subtropical regions. The aim of this study was to evaluate epidemiology of malaria in East Azerbaijan province, Iran, from 2001 to 2013. During 13 years, blood samples were taken from all suspected malaria cases using lancet and then peripheral blood smear was prepared using one blood drop. The smears were stained by Giemsa's stain and were examined under a light microscope with 1000X of magnification. All demographic variables and epidemiological recorded data were obtained from Health Center and were analyzed by SPSS v. 16 software using descriptive statistical tests. Total of 133 cases were fined to be infected by malaria in 13 years that the highest rate (54.13 %) was observed in Kaleybar county. One hundred and fifteen (86.46 %) and 18 (13.54 %) out of 133 infected individuals were male and female, respectively. Mean age of the infected people was 31.57 years. The most affected age group was 30-40 years. One hundred twenty seven (95.48 %) and 6 (4.52 %) cases were infected by Plasmodium vivax and Plasmodium falciparum, respectively. Based on the findings of this study, the incidence of malaria has been declined continuously over the past decade in East Azerbaijan province, Iran.

Mitochondrial PCR-based malaria detection in saliva and urine of symptomatic patients

BACKGROUND

Malaria can be diagnosed in saliva and urine using mitochondrial PCR detection of Plasmodium DNA.

METHODS

Blood, saliva and urine were collected from 99 febrile patients referred to health centers in Sistan and Baluchestan Province, southeastern Iran, from May to November 2011. The mitochondrial cytochrome b gene of Plasmodium falciparum and Plasmodium vivax was targeted in saliva, urine and blood samples using nested PCR.

RESULTS

Nested PCR proved to be more sensitive than microscopy for the diagnosis of sub-microscopic and mixed-species infections. The results of nested PCR amplifications of saliva and urine samples showed the same specificity of 97% and sensitivity of 91% and 70%, respectively. Nested PCR amplifications of saliva samples and microscopy showed the greatest area under the receiver operating characteristic (ROC) curve and were more accurate than nested PCR amplifications of urine samples.

CONCLUSION

Nested PCR amplification of saliva samples showed good levels of detection of mitochondrial Plasmodium DNA as compared to nested PCR of blood (к=0.84; AUC=0.94), which was used as a reference standard. Based on the results of nested PCR as well as the advantages of saliva sampling, we suggest that saliva could be an alternative to blood, in malaria diagnosis, in cases where repeat sampling is required. Further studies are needed to validate these findings.

Molecular and Microscopic-Based Characterization of Plasmodium spp. in Fars and Hormozgan Provinces, South of Iran

Despite malaria control programs in recent years, malaria transmission has not been eliminated in Iran. Molecular techniques including PCR, which has proved more sensitive and specific than microscopic examination methods, help to detect infection in low levels of parasitemia and mixed infections. Main our objectives were setting up nested PCR for detection of malaria and evaluating PCR based on plasmodia DNA from blood smears in Fars province, the comparison of this method with traditional microscopy and also evaluate the data in comparison with its neighboring province, Hormozgan. A total of 149 malaria positive samples including 116, 19, and 14 samples from Shiraz, Jask, and Lengeh ports were utilized in this study, respectively. Blood slides were prepared for microscopic observation. DNA from thin smears was extracted and nested PCR was analyzed using rPLU5 and rPLU6 for genus specification, rFAL1, rFAL2, and rVIV1, rVIV2 for P. falciparum and P. vivax detection, respectively. The results showed that 126 (84.6%), 16 (10.7%), and 7 (4.7%) out of 149 cases were positive for P. vivax, P. falciparum, and mixed infections, respectively, by microscopy. The PCR indicated that 95 (63.7%), 15 (10.1%), and 22 (14.8%) cases were infected with P. vivax, P. falciparum, and mixed mentioned species, respectively, and 17 (11.4%) cases were uninfected. Our results confirmed the considerable sensitivity of nested PCR for detection of the mixed infections. Simultaneous application of PCR even based on microscopy slides can facilitate access to the highest level of confidence in malaria researches.

Molecular phylogenetic analysis of Anopheles and Cellia subgenus anophelines (Diptera: Culicidae) in temperate and tropical regions of Iran

Molecular studies on population genetics of speciation across Iran have recently started. Morphological and molecular studies have showed that 25 species of genus Anopheles are present in the country; however, relationships between vector and non-vector species as well as compatibility of morphological characters with molecular data have not been verified. Molecular phylogenetic analysis was undertaken on the Anopheles and Cellia subgenus members internal transcribed spacer 2 (ITS2) sequences submitted to GenBank among the Oriental and Palearctic members in north and southern Iran. rDNA-ITS2 sequences were extracted from the GenBank and analyzed using bioinformatics softwares: BLAST, ITS2 annotation tool (version 3.0.13), ClustalW, and MEGA5 in neighbor-joining and maximum likelihood algorithms. There are not any submitted sequences in GenBank from Iran for the following seven species: Anopheles algeriensis, Anopheles marteri, Anopheles plumbeus, Anopheles peditaeniatus, Anopheles melanoon, Anopheles subpictus, and Anopheles mongolensis; therefore, they have not been included in the study. Although these molecular-based phylogenetic trees match well enough with classical morphological taxonomy, the arrangement of species did not match with morphological classification in some cases. Correct species identification is essential for control of vector born disease such as malaria; therefore, phylogenetic methods will help to understand the relationship among the members of the target species within the genus Anopheles. It could also help us to design molecular markers for species differentiation particularly in cryptic species, which is difficult to classify them based on morphological features.

Anopheline species composition in borderline of Iran-Azerbaijan

Malaria is still one of the most important health-problems in the world and is endemic in Iran. Since 1994, after collapse of former Soviet Union, a new threat of malaria importation emerged from those countries into the northern Iran. This work was carried out to provide further evidence on the status of anopheline species composition, the malaria parasite species, and natural infectivity of mosquitoes distributed in Pars-Abad district, on the borderline of Azerbaijan in northwestern Iran. Mosquitoes were collected from May to December 2008 in anopheline seasonal activity and were identified at the species level. The genus- and species-specific primers against Plasmodium ssrDNA gene were used for specific amplification on female mosquito head+thorax. Members of the Anoheles maculipennis complex were identified by sequence analysis of the ribosomal internal transcribed spacer II (ITS2-rDNA). Morphological character-based identification showed that out of 1455 anopheline female specimens, 1121 (77%) were of A. maculipennis s.l. and 334 (23%) were of Anoheles hyrcanus. Molecular analysis of the species complex indicated the presence of Anoheles sacharovi 984 (67.6%) and A. maculipennis 137 (9.4%) in the region. None of themosquito's head-thorax was found to be naturally infected by malaria parasite. Results of this study, particularly high dominance of A. sacharovi, suggest a potential risk of malaria epidemic in the region, and the need for a continuous epidemiological surveillance.

IgG subclasses pattern and high-avidity antibody to the C-terminal region of merozoite surface protein 1 of Plasmodium vivax in an unstable hypoendemic region in Iran

The C-terminal region of Plasmodium vivax merozoite surface protein 1 (PvMSP-1(19)) is a leading vaccine candidate for inclusion in a polyvalent malaria vaccine. In the present study, the IgG subclasses profile and the avidity of IgG to PvMSP-1(19) were evaluated in individuals (n=94) naturally exposed to P. vivax parasite in malaria endemic areas in Chabahar districts, Iran. In individuals with patent P. vivax malaria, 86.1% was sero-positive to PvMSP-1(19) and IgG1 (81.9%) was the predominant subclass. In addition, to determine the persistence of specific IgG, IgG1 and IgG3 antibodies to PvMSP-1(19), the frequency of antibodies was determined in the infected subjects (n=74) after treatment with standard chloroquine and it was detected that the frequency of responders was significantly reduced to 51.3%, 51% and 16.2%, respectively. The antigen-binding avidity of IgG antibodies to PvMSP-1(19) was measured in sero-positive sera and the high-avidity of IgG, IgG1 and IgG3 was found in 66.6%, 61% and 47% of the infected subjects with P. vivax, respectively. The present result shows that individuals who exposed to vivax malaria in the endemic region in Iran develop antibodies with high-avidity to PvMSP-1(19). These results could help to understand the interactions between the host and P. vivax parasite in development of MSP-1(19)-based vaccine.

Analysis of von Willebrand factor A domain-related protein (WARP) polymorphism in temperate and tropical Plasmodium vivax field isolates

BACKGROUND

The identification of key molecules is crucial for designing transmission-blocking vaccines (TBVs), among those ookinete micronemal proteins are candidate as a general class of malaria transmission-blocking targets. Here, the sequence analysis of an extra-cellular malaria protein expressed in ookinetes, named von Willebrand factor A domain-related protein (WARP), is reported in 91 Plasmodium vivax isolates circulating in different regions of Iran.

METHODS

Clinical isolates were collected from north temperate and southern tropical regions in Iran. Primers have been designed based on P. vivax sequence (ctg_6991) which amplified a fragment of about 1044 bp with no size variation. Direct sequencing of PCR products was used to determine polymorphism and further bioinformatics analysis in P. vivax sexual stage antigen, pvwarp.

RESULTS

Amplified pvwarp gene showed 886 bp in size, with no intron. BLAST analysis showed a similarity of 98-100% to P. vivax Sal-I strain; however, Iranian isolates had 2 bp mismatches in 247 and 531 positions that were non-synonymous substitution [T (ACT) to A (GCT) and R (AGA) to S (AGT)] in comparison with the Sal-I sequence.

CONCLUSION

This study presents the first large-scale survey on pvwarp polymorphism in the world, which provides baseline data for developing WARP-based TBV against both temperate and tropical P. vivax isolates.