Absence of dihydropteroate synthase gene mutations in Pneumocystis jirovecii isolated from Swedish patients

• Published in: Medical mycology (Oxford) Vol. 50; no. 3; p. 320
• Main Authors: Beser, Jessica, Dini, Leigh, Botero-Kleiven, Silvia, Krabbe, Margareta, Lindh, Johan, Hagblom, Per
• Format: Journal Article
• Language: English
• Published: England 01.04.2012
• Subjects: Dihydropteroate Synthase - genetics; DNA, Fungal - chemistry; DNA, Fungal - genetics; Humans; Immunocompromised Host; Pneumocystis carinii - enzymology; Pneumocystis carinii - genetics; Pneumocystis carinii - isolation & purification; Pneumonia, Pneumocystis - microbiology; Point Mutation; Polymerase Chain Reaction; Retrospective Studies; Sequence Analysis, DNA; Sweden
• ISSN: 1460-2709
• DOI: 10.3109/13693786.2011.593051

Pneumocystis jirovecii remains an important cause of pneumonia in the immunocompromised host, with the largest group of patients at risk for P. jirovecii pneumonia (PCP) in Sweden being those with haematological diseases. Widespread prophylaxis and treatment for P. jirovecii with sulfa-containing drugs have effectively decreased the incidence of PCP, but concerns have been raised about the possible emergence of P. jirovecii isolates that are resistant to these drugs. Two point mutations in the gene coding for the dihydropteroate synthase enzyme (DHPS) in P. jirovecii have been shown to be associated with prior exposure to sulfa drugs. We retrospectively studied the occurrence of P. jirovecii DHPS mutations in isolates recovered from 103 Swedish patients. The DHPS gene, including the polymorphic positions 165 and 171, were amplified and sequenced by pyrosequencing technology. All the clinical specimens showed a wild-type pattern indicating that the occurrence of P. jirovecii DHPS mutations in Sweden is very low or absent.