Pseudomonas aeruginosa Strain Characterization

In this study, we used the Pseudomonas aeruginosa PAO1 (CECT 4122/ATCC 15,692) and PA14 [13 (link)] reference laboratory wild-type strains and different cystic fibrosis isolates, PAET1, PAET2, and PAET4, which were isolated from recurrent infections of three different chronic-infected patients [14 (link)]. The three different clinical isolates differed in the nature of infection they were isolated from: while PAET1 and PAET2 strains were isolated from patients that were not previously colonized, the PAET4 strain was isolated from a CF-patient that suffered from recurrent infections. In this sense, PAET1 and PAET2 could be treated as early isolates whereas PAET4 as a late P. aeruginosa clinical isolate. The isogenic nrdJ and nrdD mutants in the PAO1 strain were also used [15 (link)]. Overnight (O/N; ~16 h) cultures of P. aeruginosa were routinely grown in Luria-Bertani medium (LB; Scharlab) at 37ºC with vigorous shaking. LB-agar (Scharlab) was used to count the respective bacterial colony forming units (CFU) of the P. aeruginosa strains.