Identification of Pneumocystis jiroveci dihydropteroate synthase (DHPS) genotypes. Electrophoresis on 1.5% agarose gel of DHPS polymerase chain reaction products after digestion with AccI (upper line) and HaeIII (lower line). M, molecular weight marker (123 Gibco BRL; Cergy Pontoise, France). Lane 1: double mutant genotype; lanes 2 and 5: wild genotype; lane 3: mixed infection with a wild genotype and a mutant genotype that has the mutation at nucleotide position 165; lane 4: mixed infection wit