Figure 4. Amplified fragment length polymorphism (AFLP) gel containing outbreak human and environmental Legionella pneumophila serogroup 1 isolates. M, molecular weight marker (Ladder Mix, MBI Fermentas, UK). Lanes 1 and 2, two colonies from a cooling tower of the hospital H. Lines 3 and 4, human isolates. Lanes 5 and 6, human isolates. Lanes 7–11, different environmental isolates from several Murcia installations.