House Distribution and Seasonal Abundance of Dust Mites in Three Cities in Taiwan and the Sequence Analyses of the Internal Transcribed Spacers of Ribosomal DNA in four species of Dust Mites

• Main Authors: En -Chih Liao, 廖恩慈
• Other Authors: Chau Mei Ho
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/76671785761533871166

碩士 === 國立陽明大學 === 寄生蟲學研究所 === 89 === From November, 1999 through October, 2000, house dust mites were surveyed in three urban areas of Taiwan, Taipei, Taoyaun and Taichung. Thirty-three households of healthy inhabitants and seventeen households with patients suffering from allergic hypersensitivity were included in this study. Data indicated that the density of house mites positively correlated with room temperature and relative humidity. Dermatophagoides pternyssinus and D. farinae appeared to be the most dominant species among seven species of mites. These mites appeared mostly in collections from pillow, bed covering and mattress within the bedroom. Statistical analyses was made to test the significance among mite densities for different parameters, which included nature of materials of household items, frequency of onset of air condition and dehumidifier, and the weekly clean effect. Data revealed that woolen carpet and bed covering carried more mites than other materials. They also suggested that increasing use of air condition and dehumidifier, and increasing of cleaning activity significantly lowered population. Polymerase chain reaction was used to amplify the DNA fragment containing ITS-1, 5.8S and ITS-2 for four species of mites that usually collected from house dust. These mites included colonies of D. farinae, D. pteronyssinus, two collected colonies of Tyrophagus putrescentiae and Chelytus eruditis. These fragments were cloned and sequenced. Sequence data indicate that ITS-1 appears to be longer than that of ITS-2 in these four mites. Because the length of the ITS-1 and ITS-2 differed among with species, it could be regarded as a molecular marker for species identification. Homology of nucleotide sequence homology was higher revealed between closely related species of D. farinae and D. pteronyssinus and lower among distantly related ones. Moreover, one EcoR1 cutting site exists in the sequence of D. farinae but not in D. pteronyssinus. A ratio of 1% variation was found within the sequences of two colonies of T. putrescentiae.