title: Detection of Dermatophagoides farinae in the dust of air conditioning filters.
abstract: BACKGROUND
  The allergenic dust mite species Dermatophagoides pteronyssinus and Dermatophagoides farinae generally inhabit warm moist environments. This study tested the hypothesis that these allergenic species may thrive in air conditioner filters.
  
  
  METHODS
  A year-long investigation of the dust mite population densities and species identities living in air conditioner filters in Shenzhen City in Southern China was performed. Additional data describing the levels of major dust mite allergen proteins from samples collected in July and August 2004 were analyzed. Genetic polymorphism analysis of Der f 1 and Der f 2 genes in the collected animals was also conducted.
  
  
  RESULTS
  Our investigation revealed that larval dust mites started to grow in March, from which time their populations proceeded to steadily increase until reaching their population zenith in July and August. The dust mite populations decreased sharply in October and live dust mites were no longer observed in the winter. Among the mites collected in July and August, 30.1 and 25.8% were of the species D. farinae. The concentration of Der f 1 was 3.04 +/- 1.75 and 3.21 +/- 1.84 microg/g dust in July and August, respectively, and that of Der f 2 was 2.15 +/- 0.82 and 2.04 +/- 1.15 microg/g dust. Four types of Der f 1 and 5 types of Der f 2 cDNA sequences were cloned from collected Der f mites. Their sequences were highly homologous with those previously published in GenBank (No. AB034946.1 and No. AB195580.1).
  
  
  CONCLUSIONS
  This research demonstrated that Der f allergens exist in the dust of air conditioner filters in this area.
authors.affiliation: College of Life Science, Shenzhen University, Shenzhen, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Liu
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.forename: Kunmei
authors.initials: K
authors.lastname: Ji
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Liu
authors.forename: Chengyu
authors.initials: C
authors.lastname: Cai
authors.forename: Haiqiong
authors.initials: H
authors.lastname: Yu
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Bao
authors.forename: Yuyin
authors.initials: Y
authors.lastname: Lian
authors.forename: Bo
authors.initials: B
authors.lastname: Gao
mesh_terms: D000389:Air Conditioning / Q000295:instrumentation; D000485:Allergens / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D000818:Animals; D039741:Antigens, Dermatophagoides / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D060829:Arthropod Proteins; D002681:China; D003546:Cysteine Endopeptidases; D040001:Dermatophagoides farinae / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D004391:Dust / Q000276:immunology*; D005374:Filtration / Q000295:instrumentation; D012621:Seasons
chemical_list: D000485:Allergens; D039741:Antigens, Dermatophagoides; D060829:Arthropod Proteins; C451160:Dermatophagoides farinae antigen f 2; D004391:Dust; D003546:Cysteine Endopeptidases; C451159:Dermatophagoides farinae antigen f 1