Browsing by Author "Kavur, Hakan"

Now showing 1 - 2 of 2

Ecological Niche Modeling Of Acanthamoeba İn Türkiye
(Springer, 2025) Kavur, Hakan; Evyapan, Gulsah; Artun, Ozan
Acanthamoeba, is an opportunistic pathogenic organism with a global distribution and the potential to cause severe human infections. This study primarily aimed to identify the environmental factors influencing the distribution of Acanthamoeba by analyzing various bioclimatic and topographic variables, and to predict their potential current and future distribution under 2070 climate change scenarios using ecological niche modeling based on the MaxEnt algorithm. Niche modeling was performed on 20 water and 20 soil samples collected from hot springs, swimming pools, parks, and agricultural areas. The rates of positive water samples in Afyon and K & uuml;tahya were 70 and 50%, respectively. We detected 60 and 100% positive rates of soil samples collected in Afyon and K & uuml;tahya, respectively. Niche modeling incorporated 19 bioclimatic variables, with BIO3 (Isothermality), BIO4 (Temperature seasonality), BIO13 (Precipitation of the wettest month), and BIO15 (Precipitation seasonality) identified as the most influential predictors. The model showed high predictive performance, with AUC values of 0.991 and 0.977 for current and future projections, respectively. Results suggest a potential increase in Acanthamoeba distribution in future scenarios, especially in the southwestern region of Afyon and southern K & uuml;tahya. These findings highlight the importance of environmental monitoring and genotypic characterization of Acanthamoeba for public health risk assessment.
The Lethal Effects of High-Frequency Ultrasound Waves in Pediculus Humanus Capitis (Anoplura: Pediculidae) Nymphs and Adults
(Çukurova University, Faculty of Medicine, 2025) Kavur, Hakan; Ozkurt, Halil; Evyapan, Gulsah; Kalkan, Sumeyye; Celik, Zehra; Kurcan, Emine; Alptekin, Davut
Purpose: This study aimed to assess the efficacy of high-frequency ultrasound waves as a non-chemical alternative for controlling head lice (Pediculus humanus capitis) by evaluating mortality rates in adult and nymphal stages exposed to various ultrasound frequencies. Materials and Methods: A total of 1,000 head lice (adults and nymphs) collected from infested children were exposed under controlled laboratory conditions to five ultrasound frequencies (0.5, 1.0, 1.5, 2.0, and 2.5 MHz) for up to 24 hours. A control group of 200 lice was maintained under the same laboratory conditions without ultrasound exposure. Mortality was recorded at 1, 2, 4, 8, 16, and 24 hours. Results: Among the 1,000 head lice tested, ultrasonic frequencies of 1.5, 2.0, and 2.5 MHz caused the highest mortality, reaching >= 90% in adults and >= 98.3% in nymphs. In contrast, 0.5 MHz produced the lowest mortality (20-21.7%), while the control groups showed only 8.3% (nymphs) and 15.0% (adults) mortality. Most deaths occurred within 8-24 hours post-exposure. Correlation analysis revealed a strong positive relationship between mortality and exposure time (r = 0.710, p < 0.001). ANOVA confirmed significant effects of frequency on mortality (F(5, 330) = 6.845, p < 0.001), with mortality plateauing at 2.5 MHz. Probit regression estimated LT50 values of 12.1-13.4 hours for adults and 15.4-17.6 hours for nymphs at higher frequencies, compared to 22.2 and 27.3 hours, respectively, at 0.5 MHz. Conclusion: This study is the first to demonstrate the direct effect of ultrasonic sound frequencies on Pediculus humanus capitis. High-frequency ultrasound (1.5-2.5 MHz) effectively controlled head lice without the need for additional chemicals, highlighting its potential as a non-chemical pediculosis management strategy. These findings provide a basis for future research and the development of portable devices, such as hair clips or necklaces, designed to repel or inactivate lice. Incorporating high-frequency ultrasound alongside routine combing may enhance head lice control, and further studies are warranted to optimize device design and exposure parameters.