Chronic colonization with Pandoraea apista in cystic fibrosis patients determined by repetitive-element-sequence PCR

Pandoraea apista is recovered with increasing frequency from the lungs of patients with cystic fibrosis (CF) and may represent an emerging pathogen (I. M. Jorgensen et al., Pediatr. Pulmonol. 36:439-446, 2003). We identified two CF patients from our hospital whose sputum specimens were culture positive for P. apista over the course of several years. Repetitive-element-sequence PCR was employed to determine whether sequential isolates that were recovered from these patients represented a single clone and whether each patient had been chronically colonized with the same strain. Banding patterns generated with ERIC primers, REP primers, and BOX primers showed that individual patient isolates had a high degree of similarity (> 97%) and were considered identical. However, only the banding patterns from the ERIC primers and BOX primers were able to show that the strains from patients I and II were unique (similarity indices of 79.8% and 70.0%, respectively). We concluded that all strains of A apista from patient I were identical, as were all strains from patient II, establishing chronic colonization. Only two of the three methods employed indicate that the strains from the two patients are distinct. This implied that the organism was not transferred from one patient to the other, suggesting that the choice of methodology could generate misleading results when examining person-to-person transmission regarding this organism.