Identification of Knockdown Resistance Mutations in the Cimex hemipterus (Hemiptera: Cimicidae) in Iran.

The worldwide resurgence of tropical bed bug Cimex hemipterus beginning in the late 1990s has led to growing concern. Molecular data on pyrethroid resistance, which is essential for the control strategies, is unknown for C. hemipterus in Iran. The current study evaluated the deltamethrin resistance status of C. hemipterus by bioassay and molecular tests. Live bed bugs were collected from sleeping quarters (dormitories) in the city of Tehran and used for insecticide bioassay tests. For bioassay evaluation, mixed-sex pools of adult bugs were exposed to deltamethrin (0.025%)-treated paper. Polymerase chain reaction assay evaluated resistance-related mutations in the voltage-gated sodium channel gene (VGSC) gene of studied populations. On the basis of the bioassay test within the 48-h exposure to deltamethrin, C. hemipterus were determined to be resistant. Knockdown time ratios (KR50) in the studied populations of C. hemipterus was 5.5-fold compared with those of the C. lectularius Teh strain. DNA sequencing of the VGSC gene revealed the presence of mutations at M918I and L1014 in C. hemipterus. According to the bioassay and molecular results of current study, C. hemipterus showed a high degree of pyrethroid resistance. The application of multiple approaches including physical, biological, and chemical tests should be regarded in future bed bug control strategies.

The Prevalence of Parasitic Contamination of Fresh Vegetables in Tehran, Iran

Objective: Parasitic diseases have created numerous health and economic problems in developing and developed countries. One of the most prevalent ways of transmitting diseases is by consuming raw vegetables that are contaminated with parasites. With respect to the importance of healthy vegetable consumption, an awareness of vegetable status helps prevent infection. Therefore, the present study was conducted to determine the level of parasitic contamination of vegetables consumed in Tehran. Methods: This descriptive and cross-sectional study was conducted on vegetable samples spread in Tehran from October 2017 to September 2018. The samples included 240 vegetables selected from 10 types of vegetable including leek, basil, mint, spring onion, radish, parsley, lettuce, cress, tarragon and coriander. Each sample was examined after passing through washing and centrifuging. Parasitic agents such as unicellular, egg and larva of the worms were studied. The data were analysed using SPSS software. Conclusion: Parasitic infection was observed in 62 samples (25.8%). The highest and lowest rates of contamination were observed in coriander and lettuce, respectively. Rhabditoid larva (12.5%; 15 cases) and Physaloptera egg (1.6%; 2 cases) were the most and least observed parasites, respectively. Other parasites such as Entamoeba, Giardia, Blastocystis, Hymenolepis, Ascaris and the egg and larva of hookworms were also observed. Despite the relative improvement of social, agricultural, economic and health conditions in Tehran, the prevalence of parasitic infections still persists. Factors such as developing modern waste collection methods, improving urban sewage systems, preventing domestic animal traffic on pastures and promoting the knowledge of different classes of people could reduce the prevalence of these types of diseases.

Suramin could block the activity of Arabinono-1, 4-lactone oxidase enzyme from Leishmania donovani: structure-based screening and molecular dynamics analyses.

BACKGROUND: Leishmania donovani, a parasitic protozoan causing visceral leishmaniasis, can lead to a dangerous and often fatal disease in humans. Current treatment for leishmaniasis may have severe side effects, low efficacy and high cost, hence an immediate need for new efficient drugs is essential. Arabinono-1, 4-lactone oxidase enzyme from Leishmania donovani (LdALO), which catalyzes the last step of the ascorbate biosynthesis pathway, has been considered as a potential target for antileishmanial drugs design. METHODS: The current study was performed with an in silico approach to predict novel inhibitory molecules against the LdALO enzyme. Various modeling and refinement processes were employed to obtain a reliable 3D structure. RESULTS: The best LdALO model with the highest qualitative model energy analysis score was predicted by the Robetta server and subsequently refined by 3D refine and ModLoop servers. The high quality of the final LdALO model was confirmed using model assessment software. Based on docking analysis results, we predicted 10 inhibitory molecules of a US Food and Drug Administration-approved library, with appropriate criteria regarding energy binding and interaction with the main functionally active sites of LdALO, indicating that they could be significant targets for further drug design investigations against L. donovani. CONCLUSION: Suramin is used to treat the first stage of African sleeping sickness and its mechanism of action is unknown. Our results showed that suramin was the best-predicted inhibitor compound for LdALO enzyme activity.

Retraction Note: Effects of Nano-particles on Histo-pathological changes of the fish.

[This retracts the article DOI: 10.1186/s40201-015-0216-9.].

Prevalence and molecular characterization of Cryptosporidium spp. and Giardia intestinalis in household dogs and cats from Shiraz, Southwestern Iran.

In the present study, a total of 615 fecal samples from veterinary clinics were screened by microscopy for the presence of Cryptosporidium and Giardia oocysts. Molecular genotyping of Cryptosporidium and Giardia were carried out using PCR and sequence analysis. Overall, Cryptosporidium and Giardia oocysts were detected in the 0.6% (2/315) and 1.9% (6/315) of dogs and in the 0.7% (2/300) and 1.3% (4/300) of cats, respectively. Sequencing revealed the presence of C. canis (n = 2) in dogs and C. felis (n = 2) in cats. Moreover, G. intestinalisassemblage D (n = 2), C (n = 3) and A, sub-assemblage AII (n = 1) were identified in dogs; G. intestinalis assemblage F (n = 3) and assemblage A, sub-assemblage AI (n = 1) were identified in cats. The highest prevalence of Giardia was observed in dogs younger than one year (6/315), and in those with diarrhea (p < 0.05). Data of the study suggest that dogs and cats play a minor role in the zoonotic transmission of cryptosporidiosis and giardiasis in Southwestern Iran.

Cryotherapy of cutaneous leishmaniasis caused by Leishmania major in BALB/c mice: A comparative experimental study.

BACKGROUND & OBJECTIVES: Leishmania parasites are sensitive to very low temperature. Cryotherapy is considered as an alternative to the existing pentavalent antimonials, for local treatment of cutaneous leishmaniasis (CL). Normally, liquid nitrogen (N2) at a temperature of -196 °C, is used in cryotherapy of CL, but it's efficacy is not consistent. Recently, few studies have also reported the use of carbon dioxide (CO2) slush at -78.5 °C in CL cryotherapy. This study was aimed to evaluate the effectiveness of N2 vs CO2 cryotherapy for CL treatment in mice. Methods: In total, 21 BALB/c mice were infected with Leishmania major strain [MRHO/IR/74/ER]. Samples were divided into three groups based on the intervention provided-Solid CO2 cryotherapy, liquid N2 cryotherapy and control group; with seven mice randomly assigned to each group. Control group received no intervention, and in the other two groups cryotherapy was used every two weeks for maximum of three months. Follow up examinations were scheduled at the time of cryotherapy, during which the size of each lesion was measured. For three mice in each study group, the spleen parasite DNA load was quantified using real-time PCR. RESULTS: After treatment, the liquid N2 cryotherapy showed significant reduction in size of the lesions (p = 0.029) as compared to the solid CO2 cryotherapy and control group. Also, Leishmania DNA load in spleen was significantly lower in the mice receiving liquid N2 cryotherapy (p <0.001). INTERPRETATION & CONCLUSION: Liquid N2 cryotherapy is superior to CO2 cryotherapy, and it can be an effective method for controlling L. major infection. Further investigations are essential to find optimal number of treatment sessions and time intervals.

Bioinformatics analysis of single and multi-hybrid epitopes of GRA-1, GRA-4, GRA-6 and GRA-7 proteins to improve DNA vaccine design against Toxoplasma gondii.

Toxoplasma gondii, is a causative agent of morbidity and mortality in immunocompromised and congenitally-infected individuals. Attempts to construct DNA vaccines against T. gondii using surface proteins are increasing. The dense granule antigens are highly expressed in the acute and chronic phases of T. gondii infection and considered as suitable DNA vaccine candidates to control toxoplasmosis. In the present study, bioinformatics tools and online software were used to predict, analyze and compare the structural, physical and chemical characters and immunogenicity of the GRA-1, GRA-4, GRA-6 and GRA-7 proteins. Sequence alignment results indicated that the GRA-1, GRA-4, GRA-6 and GRA-7 proteins had low similarity. The secondary structure prediction demonstrated that among the four proteins, GRA-1 and GRA-6 had similar secondary structure except for a little discrepancy. Hydrophilicity/hydrophobicity analysis showed multiple hydrophilic regions and some classical high hydrophilic domains for each protein sequence. Immunogenic epitope prediction results demonstrated that the GRA-1 and GRA-4 epitopes were stable and GRA-4 showed the highest degree of antigenicity. Although the GRA-7 epitope had the highest score of immunogenicity, this epitope was instable and had the lowest degree of antigenicity and half-time in eukaryotic cell. Also, the results indicated that GRA4-GRA7 epitope and GRA6-GRA7 had the highest degree of antigenicity and immunogenicity among multi-hybrid epitopes, respectively. Totally, in the present study, single epitopes showed the highest degree of antigenicity compared with multi-hybrid epitopes. Given the results, it can be concluded that GRA-4 and GRA-7 can be powerful DNA vaccine candidates against T. gondii.

Stimulated and Unstimulated Saliva Levels of Calcium and Magnesium in Giardiasis.

Giardia lamblia causes malabsorption. The aim of this study was to evaluate serum and saliva calcium and magnesium levels in patients with giardiasis. Thirty patients with giardiasis as a case and 30 person without giardiasis as a control group were enrolled. The stimulated and unstimulated whole saliva and serum calcium and magnesium levels were assayed by Arsenazo reaction and xylidyl blue complex methods, respectively. Mean calcium and magnesium level was low in serum and stimulated saliva of case group than that of controls. However, they were higher in the unstimulated saliva of the case group. It is suggested that patients suffering from giardiasis have low calcium and magnesium levels, and they lose the most of calcium and magnesium by saliva during unstimulated condition.

Effects of Nano-particles on Histo-pathological changes of the fish.

Regarding fast development of the nanotechnology and the probably of it's side effects on aquatic body organs, this study investigate the effects of nanosilver administration on histology of gill, kidney and biochemical parameters in common carp. The silver nanoparticles were synthesized in a one-step reduction process in an aqueous solution. 60 O. mykiss were obtained from a local commercial hatchery. Fish were divided randomly into four groups. Control group was kept in dechlorinated tap water without any add-on material. Experimental groups were exposed to concentration of 3, 300 and 1000 mg/L of nanosilver solution for eight weeks, respectively. Biochemical analyses of sera, histological alterations of the gill and kidney tissue were done. Aneurism in the secondary lamellae and hyperplasia of epithelium in gills, adhesion of the gill lamellae, inducing hyaline cast formation, significant decreasing in the glomerular diameter and formation of intra cytoplasmic vacuoles in the various urinary tubules were seen in experimental groups. The serum levels of total protein was decreased significantly (P < 0.05) by increasing nanosilver concentration but ALP, LDH, AST and ALT increased significantly (P < 0.05). It is concluded that nanosilver induces gill and kidney damages and changes the biochemical parameters of O. mykiss juveniles in different concentrations.

Anti-Toxoplasma gondii Antibody Levels in Blood Supply of Shiraz Blood Transfusion Institute, Iran.

BACKGROUND: The prevalence of Toxoplasma gondii infection in the blood donors has been poorly studied. The aim of this study was to assess the prevalence of acute and chronic toxoplasmosis in blood products. METHODS: A total of 250 blood products (112 fresh frozen plasma and 138 packed cells) in the Blood Transfusion Institute, Shiraz, Iran were tested for specific T. gondii antibodies (IgG and IgM) by ELISA method in 2013. Positive IgG anti-T. gondii samples were further tested for IgM anti-T. gondii antibody. A positive IgG test with the negative and positive IgM test was interpreted as a chronic and acute toxoplasmosis, respectively. The relationship of jobs, blood types, sex, marital status and residency of participants with chronic toxoplasmosis prevalence were statistically analyzed by χ(2). RESULTS: Of 250 samples, 58 (23.2%) and one were positive for IgG anti-T. T. gondii (chronic) and IgM anti-T. T. gondii (acute) antibodies levels, respectively. Twenty nine (25.9%) of fresh frozen plasma (FFP) samples were positive for IgG anti-T. gondiiiand 1(0.89%) of them was positive for IgM anti-T. gondiii antibody. Thirty (21.74%) of packed cell samples were positive for IgG anti-T. gondii antibody. The prevalence of chronic toxoplasmosis was significantly higher in workers, farmers, house wives, unemployed and free jobs (P=0.007), people with low education levels (P=0.035) and B type of blood ABO system (P=0.0001). However, there were no significant differences regarding to age, sex, marital status, residency and type of blood products. CONCLUSIONS: There were chronic and acute toxoplasmosis in blood products and the prevalence of toxoplasmosis especially chronic form was high. Therefore screening of blood for T. gondii antibodies may be considered.