Journal of Arthropod-Borne Diseases最新文献

Background: Ticks are vectors of many pathogens that involve various important diseases in humans and animals, they have several diverse hosts consequently can retain a diverse group of indigenous microbes, from bacteria to fungi. Little is known about the prevalence and diversity of tick microflora colonizing the midgut and their effects on ticks and their interaction. This information is important for development of vector control strategies.

Methods: This study was carried out in northern Iran during autumn 2019. Ticks, Ixodes ricinus caught alive on the bodies of domestic animals in the fall. The tick homogenate was prepared. The identification of fungal isolates was carried out according to a combination of macro and microscopic morphology and molecular sequencing. Pathogenic bacteria of the family Borreliaceae, Francisella tularensis, Borrelia burgdorferi and Coxiella burnetii were tested by real-time PCR.

Results: A total of 133 mature I. ricinus ticks were collected from domestic animals, including 71.5% cattle and 28.5% sheep. The tick frequency rates were 87.21% for Mazandaran, 8.28% for Golestan and 4.51% for Gilan Provinces. Total prevalence of fungal tick contamination was 53.4% (75/133) of which Trichoderma harzianum (57%) was the most prevalent species followed by Aspergillus spp. (42%), Mortierella alpine (19%) and Penicillium polonicum (14%). All tick samples were negative for three pathogenic bacteria including Francisella tularensis, Coxiella burnetii, and Borrelia burgdorferi by real-time PCR analysis.

Conclusion: These results show a first picture of the microbial diversity of ticks and highlight the importance of microbiota and their role in host-pathogen interaction.

Background: Among the blood-borne parasitic infections of dogs, trypanosomosis and babesiosis are highly prevalent in the Indian subcontinent and highly pathogenic.

Methods: A six-month-old dog was presented with complaint of lethargy, anorexia and loss of body weight over the previous 15 days on October 11, 2021. A full clinical and targeted haematologic and parasitological examination was undertaken.

Results: Wet smears were positive for the motile trypanosomes while stained thin blood smears showed large number of extracellular trypanosomes and intra-erythrocytic ring-like inclusion bodies of Babesia spp. A high burden of Toxocara canis was identified on coprological examination.

Conclusion: This report describes the clinical manifestation of concurrent infection of haemoparasites and gastrointestinal nematodes in Pakistani dogs, and highlights the importance of prompt veterinary intervention.

Background: Anopheles stephensi is an important malaria vector mosquito in Iran and other western Asian countries. In many human communities, plant products have been used traditionally instead of synthetic pesticides for mosquito control due to their minimal hazardous effects. Teucrium polium, known popularly as felty germander, has been introduced in Persian Medicine (PM) as an insect repellent from a long time ago.

Methods: The present study was undertaken to evaluate repellent and larvicidal activity of dichloromethane (DCMETP) and ethanolic extracts (EE-TP) of T. polium against An. stephensi under laboratory conditions. The possible chemical components of the extracts were also investigated through gas chromatography/mass spectrometry (GC-MS) technique.

Results: Based on the results, DCME-TP showed better repellent activity than EE-TP with 56.67 and 28.33 % protection, respectively. Larvicidal activity of DCME-TP with 49.41% mortality was also higher than EE-TP (20.24%). The main identified constituents of DCME-TP were long chain alkanes, phenol, aromatic ester, oxaspiro and triterpenoid. While phenolic and aliphatic acid were only the identified components in EE-TP. It is notable that lupeol was detected in DCME of T. polium for the first time.

Conclusion: DCME-TP can be considered as a new herbal candidate to control An. stephensi mosquitoes. Further studies are required on this extract for the fractionation and identification of the active compounds, and the evaluation of their bioactivity in the laboratory and field.

Background: Phlebotomine sand flies are vectors of Leishmania species, the causative agents of leishmaniasis in the world. Present study aimed to evaluate the bioecological aspects of sand flies in different ecotopes in Sari County, north of Iran.

Methods: Sand flies were collected from four villages in mountainous, forest, plain and peri-urban areas monthly using sticky traps in May-October 2016. Mounted specimens were identified using valid identification keys under optical microscope. The Arc GIS 10.5 software was applied for showing the distribution of sand flies. Shannon-Weiner, Simpson and Evenness species diversity indices were calculated.

Results: Generally, 334 specimens were captured and identified, namelly Phlebotomus kandelakii, Ph. papatasi, Ph. major, Ph. sergenti, Ph. longiductus, Ph. halepensis, Ph. tobbi, Sergentomyia dentata, Se. theodori, Se. sintoni, Se. antennata and Se. sumbarica. The most common species was Ph. kandelakii (n= 128, 38.32 %). The highest Simpson index (0.81) and abundance (N= 141) were recorded in the mountaineous area. Shannon diversity index was higher in the forest (H'= 1.53) and the highest evenness index was in the plain area (J'= 0.93). The highest richness (S= 9) and Shannon indices (H'= 1.57) were observed in June.

Conclusions: Phlebotomus kandelakii, Ph. sergenti, Ph. tobbi, Ph. longiductus, Se. theodori, Se. antennata and Se. sumbarica were recorded for the first time in the study area. Since some species are incriminated for leishmaniasis transmission, further studies are required in the northern regions of Iran to timely control measures planning.

Background: Hemiscorpius lepturus is one of the most dangerous scorpions in Iran and the world. Numerous studies have been conducted on phospholipases, especially phospholipase D, in this scorpion's venom, and the results have shown this protein to be the main cause of death. Therefore, one of the most effective ways of preventing fatalities is to produce a toxoid vaccine from the deadly toxin of the venom. The present study was conducted to assess the non-toxicity of this toxoid and the safety of the vaccine candidate in BALB/c mice.

Methods: The production of interferon-gamma and interleukin-4 cytokines in the spleen cells of the mice was measured using ELISpot assay 28 days following immunization with rPLD toxoid.

Results: The unpaired t-test results showed a significant increase in the concentration of IFN-γ cytokine in the vaccinated mice (P= 0.001), indicating that the immune system is directed toward the Th1 pattern, while no significant difference was observed in the levels of IL-4 (P= 0.16) despite an increase in this cytokine. The in-vivo tests showed that the mice immunized with interval doses of 80µg of toxoid were completely protected against 10 × the LD₁₀₀ of the venom. Moreover, the toxoid had no dermonecrotic effects and caused no necrotic and inflammatory complications in the rabbit skin.

Conclusion: As a vaccine, the toxoid has the potential to increase the Th1 cytokine response and, subsequently, increase acquired cellular immunity. Thus, this toxoid appears to be able to provide an effective vaccine against the venom of Hemiscorpius lepturus.

Background: Leishmania major is the etiologic agent of zoonotic cutaneous leishmaniasis in Iran, and glucantime injection is currently used for its treatment. This study aimed to evaluate the anti-leishmanial effect of topical Plantago psyllium and white vinegar in L. major infected BALB/c mice.

Methods: Thirty infected mice were divided into five groups as follows: Group 1: treated with the combination of ovata powder and white vinegar, Group 2: treated with glucantime, Group 3: treated with white vinegar, Group 4: treated with the combination of ovata powder and water, and Group 5: without any treatment. All the groups were treated for 18 days. Lesion size was measured, and final smears were prepared for microscopic examination.

Results: The findings indicated that the difference in the mean areas of the ulcers in all the groups before and after treatment was not significant, except for the second (glucantime) and third (vinegar) groups. Also, the results showed that in the first, second, third, and fourth group, 6 (60%), 4 (80%), 3 (60%), and 2 (40%) mice were healed, respectively. However, ulcers remained in all the five mice of the control group.

Conclusion: The combination of ovata powder and white vinegar has been traditionally used to treat leishmanial lesions in Iran. It seems the most anti-leishmanial effect is related to vinegar and supported by Plantago. The route of treatment with this combination is very simple and painless in comparison with injection. Thus, further studies on this issue could help to design more effective and easy-to-use drugs.

Background: Androctonus crassicauda is the most medically relevant animal and understanding its morphological characteristics is essential in the production of antiscorpion sera.

Methods: Adults of A. crassicauda were collected from different areas of Zanjan Province and the morphometric parameters and the cuticular fluorescence patterns of samples were studied. The crude venom of samples was extracted by electric stimulation, and their biochemical properties were analyzed by the SDS-PAGE method.

Results: Values of the morphometric parameters depended on sex and altitude of the area. Except for values of the pectinal organ, these parameters in females were higher than in males. No significant difference was in the number, shape, and intensity of cuticular fluorescence patterns. The body length of males in high and lowlands was 72.53±1.53 and 77.33±2.70mm, respectively. Females' body lengths in that area were 81.66±2.19 and 86.55±2.33mm, respectively. Analysis of toxin proteins showed two isotypes that the 12, 13, 15, 16, 18, and 19kDa proteins were in all areas. However, the 41 and 74kDa proteins, and 46 and 63kDa proteins were detected in low and highlands, respectively.

Conclusion: Black fat-tailed scorpion has a considerable dominancy and developing preventive programs and providing treatment facilities in studied areas are necessary. Values of the morphological parameters and venom electrophoresis patterns depended on the geographical location. Therefore, pool crude toxin is suggested for the production of effective antivenoms. Moreover, additional field complementary works in the geographic information system based niche modeling and mass fingerprinting of scorpion venoms are suggested for screening effective isotypes.

Background: Mosquitoes (Diptera: Culicidae) are haemotophagus insects and are vectors of many arthropod-borne diseases. Present study aimed to explore species composition, seasonal abundance, spatial distribution and physio-chemical properties of larval breeding sites of mosquitoes in District Mardan, Khyber Pakhtunkhwa, Pakistan.

Methods: Both adults and larvae of mosquitoes were collected through light traps, insecticide spray, mouth aspirator and larval standard dipping method in District Mardan from May to November 2017. Water samples from larval sites were physio-chemically analysed.

Results: 5078 (3704 adults and 1374 larvae) mosquito specimens were collected in Mardan, Katlang and Takhtbhai tehsils. Six species in four genera were reported. Culex pipiens (89.80%) and Armigeres subalbatus (9.20%) were the most abundant species. Diversity was high in Takhtbhai (0.29) followed by Katlang (0.28) and Mardan (0.25). Greater number of specimens were recorded in peridomestic sites (93.97%) as compared to domestic habitats (6.03%). Culex pipiens larval abundance had negative correlation with pH whereas it correlated positively with electric conductivity, salinity, and TDS (total dissolved sulphur). Mosquito abundance peaked in August and July while the lowest was in May. Their monthly abundance had positive correlation with rainfall (r= 0.5069), relative humidity (r= 0.4439) and mean minimum temperature (r= 0.2866). Number of mosquitoes was highest at low elevation < 347m asl (above sea level) in agriculture land and near to water bodies (streams).

Conclusion: Culex pipiens being the most abundant species, was susceptible to high pH. Mosquitoes preferred habitats were at low elevation in agriculture land.

Background: Rodents and shrew living in the vicinity of human beings perform significant role to harbor different species of ectoparasites and thus act as the reservoir host for the spread of diseases to human and animals.

Methods: This study was undertaken to determine the species composition of the medically important ectoparasites present in the scrub typhus affected places of Vellore District using wonder and Sherman traps for trapping of live Rodent/Shrew during September 2017 to August 2018.

Results: Rodent/shrew hosts belonged to two Families, three sub families and five genera and five different species. These animals carried 23 species of ectoparasites including 17 trombiculid mites, two non-trombiculid mites, two ticks and two fleas. A total of 940 chigger mites were collected which belonged to three Tribes, six Genera, two Subgenera and 17 species. Adult mites collected belonged to two families, three genera and three species. Ticks collected were classified under one family, two genera and two species. Fleas fall under one family, one subfamily, one tribe, one genus and two species.

Conclusion: This is the first record of 14 species of chigger mites and three species of adult mites from Vellore District, Tamil Nadu. Surveillance of these keystone ectoparasites helped to identify the medically important disease vectors causing acari-borne zoonotic diseases.

Background: Pediculosis, caused by Pediculus spp is an important public health problem in urban and rural areas around the world. Natural compounds such as plant essential oils (EOs) have been suggested as a potential alternative for insect pest control recently. The purpose of this study was to investigate the toxicity of Foeniculum vulgare essential oil against the head louse, Pediculus capitis under laboratory conditions.

Methods: Fennel essential oil components were analyzed using GC-mass apparatus. Immersion and contact filter paper bioassays were used to evaluate fennel essential oil toxicity at the two-fold concentrations of 2.5, 5, 10, 20, and 40% against nit and nymph/adult stages of the head louse.

Results: Trans-anethole, α-Thujone, and limonene, which consisted of 76.08%, 10.37%, and 5.34% were the most components of fennel oil respectively. The LC₅₀ values for the adult /nymphs were 11.5, 6.4, 3.9, 3.1 and 2.5% and LC₉₉ values were 29.5, 15.2, 12.8, 10.8, and 7.4% at 10, 20, 30, 45 and 60 minutes after exposure respectively. The lethal times (LT₅₀) for adults/nymphs were 5.2, 8.1, 9.5, 20.5, and 45.8 minutes and LT₉₉ were 138.6, 91.3, 23.8, 21.7, and 13.9 minutes in the concentrations of 2.5, 5, 10, 20 and 40%, respectively. LC₅₀ and LC₉₉ values were 2.32% and 7.36% after 5 days for the eggs.

Conclusion: Fennel essential oil at the concentration of 15% after 20min is suggested to develop as an appropriate formulation to evaluate in clinical trials.