Erhan Zeytun

The effect of skin moisture, pH, and temperature on the density of Demodex folliculorum and Demodex brevis (Acari: Demodicidae) in students and staff of the Erzincan University, Turkey

The aim of this study was to determine the prevalence and density of Demodex folliculorum and Demodex brevis in students and staff of the Erzincan University, Turkey, and to define the influence of age, gender, educational level, and hygiene as well as skin moisture, pH, and temperature on the presence of Demodex mites.

House Dust Mites in Erzincan Province.

OBJECTIVE We aimed to determine the species of the house dust mites seen in Erzincan, the number of mites per gram of dust in the houses, and the relationship between temperature and the number of mite specimens. METHODS For this purpose, 54 dust samples collected from 18 houses located in different districts of Erzincan province between November 2013 and January 2014. These samples were examined by a lactic acid precipitation method. RESULTS Of the houses in which the dust samples were collected, 94.44% were found to be positive in terms of mites. A total of 844 mite specimens were isolated from the dust samples, and the mean number of mites per gram of dust was found to be 18.34. The most common species was found to be Acarus siro (55.55%) and was followed by Dermatophagoides pteronyssinus (50.00%), Tyrophagus putrescentiae (22.22%), Histiostoma sp. (22.22%), Lepidoglyphus destructor (16.66%), T. perniciosus(11.11%), Euroglyphus maynei (11.11%), Glycyphagus privatus (11.11%), Cheyletus sp. (11.11%), Tarsonemus sp. (11.11%), and Tetranychus sp. (11.11%). CONCLUSION Mite-holding rate of the houses in Erzincan province was found to be 94.44%. The mean number of mites per gram of dust was found to be 18.34. The most common mite species was A. siro, which was followed by D. pteronyssinus.

Prevalence and Density of Demodex folliculorum and Demodex brevis (Acari: Demodicidae) in Erzincan Province

OBJECTIVE This study aimed to determine the prevalence and density of Demodex folliculorum and D. brevis in Erzincan Province and the association between Demodex spp. and skin moisture, pH, and temperature. METHODS The study included total 300 healthy participants without dermatological ailments and residing in Erzincan Province. Moisture, pH, and temperature of the cheek were measured, and the presence of mite was determined in samples from the cheek, nasolabial, and chin region using the standard superficial skin biopsy technique. RESULTS The prevalence and density of D. folliculorum and D. brevis were found to be 61.3% (mean 14.3/cm2) and 23.3% (mean 3.2/cm2), respectively, in healthy participants. Infestation by Demodex spp. was greater in the cheek (mean 10.4/cm2), followed by the nasolabial region (mean 7.2/cm2) and chin (mean 6.6/cm2), respectively (p<0.001). The prevalence and density of Demodex spp. were greater in those with dry skin (mean 11.6/cm2), pH of 5.5-7.0 (mean 11.2/cm2), and temperature of 20-23°C (mean 13.1/cm2). Males, with aged >60 years, with lower educational status, and who were single were significantly more infested with Demodex spp. CONCLUSION Demodex mites are very prevalent in healthy individuals with different skin moisture, skin pH, skin temperature, and demographic characteristics. This may be taken into consideration when epidemiological and clinical studies are conducted on patients having different dermatological ailments.

Comparison of Living and Bedrooms in Terms of House Dust Mites in the Province of Erzincan, Turkey.

Abstract The most important factors in development of symptoms such as allergic asthma, rhinitis, conjunctivitis, and dermatitis in atopic persons are the allergens of house dust mites. The objective of this study was to compare living rooms and bedrooms, and woolen and spring mattresses in terms of the number and species of mites in houses in the province of Erzincan, Turkey. In total, 74 dust samples were collected from living rooms and bedrooms of 37 randomly selected houses from various districts of the city. All examined houses were positive for house dust mites. In total, 5,210 mites were isolated, 1,058 from the living rooms and 4,152 from the bedrooms, and the differences were statistically significant (P < 0.05). Of 4,152 mites detected in bedrooms, 1,330 (32%) were isolated from 31 spring mattresses and 2,822 (68%) from 6 woolen mattresses (P < 0.001). The study identified 14 families, 17 genera, and 16 species belonging to Astigmata, Prostigmata, and Oribatida. Of these, Dermatophagoides pteronyssinus (Trouessart) was the dominant species: living rooms, 63.3%; bedrooms, 74.4%; woolen mattresses, 84.6%; and spring mattresses, 52.8%. This was followed by Lepidoglyphus destructor (Schrank) (9.8%), Dermatophagoides farinae Hughes (5.1%), Tyrophagus putrescentiae (Schrank) (4.3%), and Acarus siro L. (2.5%) in living rooms; L. destructor (11.2%), Euroglyphus maynei (Cooreman) (4.2%), D. farinae (3.8%), and T. putrescentiae (1.0%) in bedrooms; L. destructor (11.8%), D. farinae (2.1%), E. maynei (0.3%), and T. putrescentiae (0.2%) in woolen mattresses; and E. maynei (12.5%), L. destructor (9.9%), D. farinae (7.5%), and T. putrescentiae (2.7%) in spring mattresses.

EVALUATION OF THE EFFICACY OF TEA TREE OIL ON THE DENSITY OF DEMODEX MITES (ACARI: DEMODICIDAE) AND OCULAR SYMPTOMS IN PATIENTS WITH DEMODECTIC BLEPHARITIS

Abstract The objective of this study was to examine the efficacy of 7.5% tea tree oil (TTO) eyelash shampoo on the density of Demodex (Acari: Demodicidae) and ocular symptoms in patients with demodectic blepharitis. A total of 135 patients diagnosed with demodectic blepharitis, following clinical inspection and parasitological examinations, were included in the study. Patients were treated with eyelash shampoo, with or without TTO. Full Demodex reduction was attained in 36% of the patients who used eyelash shampoo with TTO, and the average Demodex count was reduced from 6.33/eyelash to zero (P < 0.001). In contrast, the average Demodex count in patients who did not achieve full reduction (64%) was reduced from 12.46/eyelash to 4.15/eyelash (P < 0.001). Full reduction was observed in 11.7% of patients who used TTO-free eyelash shampoo, and average Demodex count reduced from 2.00/eyelash to zero (P = 0.017). The average Demodex count was reduced from 11.98/eyelash to 7.91/eyelash in patients (88.3%) who did not achieve full reduction (P = 0.024). Additionally, ocular symptom scores (which are generated based on subjective experiences of itching, burning, the feeling of a foreign body in the eye, eye redness, and cylindrical dandruff) were reduced significantly (P < 0.001) in patients who used the eyelash shampoo with TTO. The symptom scores remained almost the same in patients who used TTO-free eyelash shampoo (P > 0.05). In conclusion, it was determined that eyelash shampoo with TTO is 3 times more effective at achieving full Demodex reduction, significantly reducing the Demodex count, and relieving ocular symptoms in patients where full reduction cannot be attained, without adverse side effects.

Prevalence and Load of Demodex folliculorum and Demodex brevis (Acari: Demodicidae) in Patients With Chronic Blepharitis in the Province of Erzincan, Turkey

Abstract Chronic blepharitis is an ocular disease frequently encountered by ophthalmologists. Demodex mites can play a role in the pathogenesis of blepharitis along with bacterial agents, especially in treatment-resistant cases or recurrent cases after treatment. This study was performed to determine the prevalence and load of Demodex folliculorum (Simon) and Demodex brevis Akbulutova in chronic blepharitis patients and to assess the relationship between the prevalence and load of Demodex species and ocular symptoms. The study included 365 patients diagnosed with chronic blepharitis in clinical examination, and 175 controls without any chronic or ocular disease. In the study, two eyelashes were sampled from the lower and upper lids of the right and left eyes (a total of eight samples) of the participants. Eyelash samples were examined under a light microscope, and Demodex species were identified and counted. Demodex were detected in 79.2% (95% CI: 75–83%) of patients and 31.4% (95% CI: 24–38%) of controls in this study. D. folliculorum alone (mean: 4.96; min: 1; max: 17; P < 0.001) was detected in 72.3% of patients, in 0.7% D. brevis alone (mean: 1.00, P > 0.05), and in 27% both D. folliculorum and D. brevis (mean: 21.65; min: 2; max: 79; P < 0.001). In Demodex positive controls, only D. folliculorum (mean: 2.38; min: 1; max: 6) was detected while there was no D. brevis. Nevertheless, mean ocular symptom scores were significantly higher in Demodex positive patients than in Demodex negative patients (P < 0.001). Itching, foreign body sensation, and redness were the most common complaints in Demodex positive patients. As a result, Demodex mites were high in numbers in patients with chronic blepharitis in Erzincan. There was a positive correlation between Demodex mites and chronic blepharitis and ocular symptoms. It may be helpful to consider these findings in clinical assessment of blepharitis patients.

Structural characterization of the silk of two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae)

Abstract The present investigation was undertaken to obtain information about the structural and morphological properties of the silk of two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) by means of the atomic force microscope (AFM), scanning electron microscope (SEM), energy dispersive X-ray spectrophotometer (EDX) and attenuated total reflection Fourier transmission infrared spectroscopy (ATRFTIR) techniques. AFM images show that the shapes of silken threads produced by both female and male mites are similar and have non-uniform cylindrical structure. In general, the appearance of silks produced by female mites is smoother than those of the male mites. In addition, it is determined that the silk threads produced by both female and male individuals have single and double stranded structure. There were differences in the thread dimensions of female and male which could depend on the body size of the mites. However, there is no statistically significant correlation between the body size of the mites and their thread dimensions. The silk material was found to consist predominantly of C, N and O elements and minor fractions of Al, P, Cl and K. The ATR-FTIR spectrum of the silk of two-spotted spider mite exhibited characteristic vibrational modes originating from amid groups, which were attributed to random coil and β-sheet molecular conformation in the protein structure of the silk of two-spotted spider mite. Understanding the features of the two-spotted spider mite silks may be of practical importance for the future studies related to biomaterial and material science.