Factors Affecting the Prevalence of House Dust Mite in Tekirdag and Istanbul Provinces in Comparison with House Dust Mite Population of Sivas Province During the Same Period

Objective: This study aimed to examine the frequency of house dust mite according to various variables and determine the house dust mite population in these provinces in house dust samples collected in the same period from Istanbul and Tekirdag provinces, which is located on the coastal part of the Marmara Region, and Sivas province, which has different climatic and geographic characteristics from these provinces. A comparison was done from each province. Methods: Between May and August 2018, a total of 100 powder samples were prepared by a lactic acid precipitation method that was examined microscopically. Besides, some variables in Tekirdag and Istanbul provinces were applied to participants by face-to-face interview method from a questionnaire. Results: House dust mite was found with a rate of 66.7% in Istanbul and 61.5% in Tekirdag; however, house dust mite was not found in Sivas province. According to survey results, the frequency of house dust mite detection is 1-4. It increased according to the fact that it is located between floors, cleaning was every 15 days, no smoking at home and insufficient sun exposure. No statistically significant difference was found according to the presence of plants and/or animals in the house and way of heating. Conclusion: Measures to be taken against house a dust mite, which is the most essential component of house dust with allergic content, are observed to be important in reducing complaints of sensitive people by especially considering the climate, geographic characteristics and general hygienic conditions. According to investigations, Baloghella melis, one of the mites detected in dust samples taken from Istanbul, has been determined to be a new record in Turkey. This study will contribute to Turkey with this aspect fauna of house dust mites.

Is permanent parasitism reversible?--critical evidence from early evolution of house dust mites.

Long-term specialization may limit the ability of a species to respond to new environmental conditions and lead to a higher likelihood of extinction. For permanent parasites and other symbionts, the most intriguing question is whether these organisms can return to a free-living lifestyle and, thus, escape an evolutionary "dead end." This question is directly related to Dollo's law, which stipulates that a complex trait (such as being free living vs. parasitic) cannot re-evolve again in the same form. Here, we present conclusive evidence that house dust mites, a group of medically important free-living organisms, evolved from permanent parasites of warm-blooded vertebrates. A robust, multigene topology (315 taxa, 8942 nt), ancestral character state reconstruction, and a test for irreversible evolution (Dollo's law) demonstrate that house dust mites have abandoned a parasitic lifestyle, secondarily becoming free living, and then speciated in several habitats. Hence, as exemplified by this model system, highly specialized permanent parasites may drastically de-specialize to the extent of becoming free living and, thus escape from dead-end evolution. Our phylogenetic and historical ecological framework explains the limited cross-reactivity between allergens from the house dust mites and "storage" mites and the ability of the dust mites to inhibit host immune responses. It also provides insights into how ancestral features related to parasitism (frequent ancestral shifts to unrelated hosts, tolerance to lower humidity, and pre-existing enzymes targeting skin and keratinous materials) played a major role in reversal to the free-living state. We propose that parasitic ancestors of pyroglyphids shifted to nests of vertebrates. Later the nest-inhabiting pyroglyphids expanded into human dwellings to become a major source of allergens.