Absence of Dihydropteroate Synthase Mutations in Pneumocystis jirovecii from Brazilian AIDS Patients

Abstract

Several studies from developed countries have documented the association between trimethoprim-sulfamethoxazole prophylaxis failure and mutations in the Pneumocystis jirovecii gene coding for dihydropteroate synthase (DHPS). DNA was extracted from Giemsa-stained smears of 70 patients with P. jirovecii pneumonia seen in Porto Alegre, Brazil, from 1997 to 2004. Successful PCR amplification of the DHPS locus was obtained in 57 of 70 cases (81.4%), including five cases (8.7%) that had used sulfa prophylaxis. No DHPS gene mutations were seen. These results suggest that DHPS mutations are currently as rare in Brazil as in other developing countries.

Interhuman Transmission as a Potential Key Parameter for Geographical Variation in the Prevalence ofPneumocystis jiroveciiDihydropteroate Synthase Mutations

“…A similar prevalence was reported in Australia (13%) [18] and Japan (29%) [19]. The limited data from developing countries seem to indicate that the prevalence may be lower there than in the developed countries: 0% in Brazil [20] and China [21], 7% in Zimbabwe [22], and 12% in Thailand [23]. By contrast, the rates reported in the United States were generally higher, ranging from 26% [3] to 81% [24].…”

Mutational Analysis of Pneumocystis jirovecii Dihydropteroate Synthase and Dihydrofolate Reductase Genes in HIV-Infected Patients in China

“…The small sample sizes and relatively low frequencies among these studies preclude any conclusions about trends in prevalence over time. The overall prevalence of P. jirovecii DHPS mutations in China is similar to those reported from other developing countries (3,(8)(9)(10)(11)(12) but lower than those reported from developed countries (1-4) and may reflect the less frequent utilization of TMP-SMX or dapsone for PCP prophylaxis in developing countries.…”

High Prevalence of Dihydropteroate Synthase Mutations in Pneumocystis jirovecii Isolated from Patients with Pneumocystis Pneumonia in South Africa

“…We found that 56% of patients with PCP were infected with mutant P. jirovecii strains. This proportion stands in contrast to the lower frequencies reported from the African continent and other countries outside the industrialized world (8,12,23,25,30,34,40,46,48). The risk that P. jirovecii will develop mutations in the DHPS gene is higher for patients with PCP receiving sulfa drug prophylaxis than for those not receiving it (5,15,16,22,26,32,38).…”