مجال التميز | تميز دراسي وبحثي |
البحوث المنشورة |
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البحث (1): | |
عنوان البحث: |
Impact of mycolactone produced by Mycobacterium ulcerans on life-history traits of Aedes aegypti (L.) and resulting habitat selection for oviposition |
رابط إلى البحث: | |
تاريخ النشر: |
01/12/2020 |
موجز عن البحث: |
Buruli ulcer (BU) is a globally recognized, yet largely neglected tropical disease whose etiologic agent is Mycobacterium ulcerans. Although the exact mode of transmission is unclear, epidemiological evidence links BU incidence with slow-moving or stagnant, aquatic habitats, and laboratory-based experiments have shown disease manifestation in animals with dermal punctures. Therefore, hypotheses for transmission include contact with slowmoving aquatic habitats and associated biting aquatic insects, such as mosquitoes. Recent research demonstrated the toxin produced by M. ulcerans, mycolactone, is an attractant for adult mosquitoes seeking a blood-meal as well as oviposition sites. In the study presented here, we examined the impact of mycolactone at different concentrations on immature lifehistory traits of Aedes aegypti, which commonly occurs in the same environment as M. ulcerans. We determined percent egg hatch was not significantly different across treatments. However, concentration impacted the survivorship of larval mosquitoes to the adult stage (p < 0.001). Resulting adults also showed a slight preference, but not significant (p > 0.05), for oviposition in habitats contaminated with mycolactone suggesting a legacy effect. |
المؤتمرات العلمية |
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المؤتمر (1): | |
عنوان المؤتمر: |
ESA’s 2020 Annual Meeting, Entomology 2020 |
تاريخ الإنعقاد: |
11/11/2020 |
مكان الإنعقاد: |
USA (Virtual) |
طبيعة المشاركة: |
Poster presentation |
عنوان المشاركة: |
Target site kdr mutations in the voltage-gated sodium channel gene in pyrethroid-resistant Aedes aegypti from Saudi Arabia |
ملخص المشاركة: |
In Saudi Arabia, many outbreaks and cases of dengue fever have been reported since 1994. Pyrethroid insecticides have been used intensively in the country since 1999 against mosquitoes. This constant use has likely provided intense selection pressure for the development of target-site mutations in the voltage-gated sodium channel (VGSC) gene in Aedes aegypti that result in knockdown-resistance (kdr) against pyrethroids. Aedes aegypti in Jazan was assayed for the presence of known kdr mutations in domains IIS6 and IIIS6 of the VGSC gene using PCR amplification and sequencing. The presence of three kdr mutations S989P, V1016G (IIS6) and F1534C (IIIS6) were detected for the first time in the Jazan region but have been reported elsewhere in Saudi Arabia previously. The S989P mutation was in perfect linkage with V1016G. Mutations S989P + V1016G were present at a frequency of 0.30 and F1534C at 0.71. Of the six genotypes present, the majority (45%) were homozygous for F1534C. From the presence of SS+VV and FC genotypes in Jazan, we inferred the presence of haplotypes containing no kdr mutations, i.e. S + V and F. The presence of such haplotypes indicates that appropriate insecticide resistance management strategies have the potential to restore insecticide susceptibility to this population to prolong the effective use of pyrethroid insecticides. Haplotype and nucleotide diversity of VGSC regions was lower in Saudi Arabia than Africa, the Americas and Southeast Asia, consistent with a relatively recent spread of Ae. aegypti into the country. |