To evaluate the prevalence of Mycoplasma pneumoniae (Mp) infection in pediatric and adult patients with acute exacerbations of asthma by PCR targeting CARDS TX (MPN372) and P-1 adhesin gene (MPN141).
Nasal lavage (NL) and serum were obtained from 43 children (age 5–15) and 74 adults (age 18–64) presenting to the hospital with acute exacerbation of asthma. Adult subjects also had throat swabs (TS) and sputum collected. Subjects with other pulmonary disease or an abnormal chest x-ray were excluded. Samples were evaluated by quantitative real time PCR to genes encoding for MPN372 and MPN 141. In adults, P-1 adhesin assays were confirmed by submitting samples to a reference lab (ARUP, Utah) and MPN 372 by testing positive samples with the CDC's CARDS TX probe.
In children with AEA, NL was positive in 13/43 subjects (30.2%) by MPN372 but in only 2/43 subjects (4.2%) by the standard P-1 adhesin assay (MPN141). Serum was positive in 7/42 subjects (16.6%) by MPN372 and 2/42 subjects (4.8%) by MPN141. In adults, NL was positive in 13/74 subjects (17.6%) by MPN 372 but only 2/74 (2.7%) by MPN141. In serum 13/74 (17.6%) were positive by MPN372 vs. 0/74 (0%) by MPN 141. When additional sites (throat swab and sputum) were assayed in adults, Mp was identified in 41.9% (31/74) of subjects by CARDS TX and 4%( 3/74) by P-1 adhesin.
Mp infection is common in both adults and children with acute exacerbations of asthma. The CARDS TX gene (MPN372)is a superior target for identifying Mp infection compared to the standard P-1 adhesin gene (MPN141). Assessing multiple sites in the airway (NL, TS, and sputum) significantly increase the yield of identifying Mp.
Mp may play a significant role in the initiation of acute exacerbations of asthma. Further studies are necessary to document the pathogenic effects of Mp infection and Mp toxin in both acute and chronic asthma.
Jay Peters, No Financial Disclosure Information; No Product/Research Disclosure Information