Rapid identification of allergenic and pathogenic molds in environmental air by an oligonucleotide array

We developed an oligonucleotide array that could accurately identify 21 important airborne fungi (13 genera) that may cause adverse health problems. The method consisted of PCR amplification of the internal transcribed spacer (ITS) regions, hybridization of the PCR products to a panel of oligonucleotide probes immobilized on a nylon membrane, and detection of the hybridization signals with alkaline phosphatase-conjugated antibodies.A collection of 72 target and 66 nontarget reference strains were analyzed by the array. Both the sensitivity and specificity of the array were 100%, and the detection limit was 10 pg of genomic DNA per assay. Furthermore, 70 fungal isolates recovered from air samples were identified by the array and the identification results were confirmed by sequencing of the ITS and D1/D2 domain of the large-subunit RNA gene. The sensitivity and specificity of the array for identification of the air isolates was 100% (26/26) and 97.7% (43/44), respectively.Identification of airborne fungi by the array was cheap and accurate. The current array may contribute to decipher the relationship between airborne fungi and adverse health effect.Fungi are widely distributed in the natural environment. Fungal spores can be easily dispersed into the air and may cause serious health problems. Exposure to fungal spores can cause a wide spectrum of allergenic reactions, such as asthma, and infections in susceptible individuals [1-4]. Asthma prevalence has considerably increased in recent decades such that it is now one of the most common chronic disorders in the world [5-7]. Some severe diseases, such as allergic bronchopulmonary aspergillosis and fungal sinusitis, may be found in susceptible or immunocompromised individuals through mold exposure [8,9]. The predominant genera of airborne fungi causing health concern are Alternaria, Aspergillus, Cladosporium, and Penicillium [4].In order to decipher the relationship between fungi and potential fungal infection, it is i