Gustavo Wissmann

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.

Pneumocystis jirovecii pneumonia in developing countries

Pneumocystis pneumonia (PcP) is a serious fungal infection among immunocompromised patients. In developed countries, the epidemiology and clinical spectrum of PcP have been clearly defined and well documented. However, in most developing countries, relatively little is known about the prevalence of pneumocystosis. Several articles covering African, Asian and American countries were reviewed in the present study. PcP was identified as a frequent opportunistic infection in AIDS patients from different geographic regions. A trend to an increasing rate of PcP was apparent in developing countries from 2002 to 2010.

High prevalence of Pneumocystis jirovecii colonization in Brazilian cystic fibrosis patients.

A high rate of Pneumocystis jirovecii colonization was observed in Brazilian cystic fibrosis (CF) patients (13 out of 34; 38.2%) who underwent bronchoscopy between March 2006 and August 2009 at the Hospital de Clinicas de Porto Alegre, Brazil. Bronchoalveolar lavage samples were collected from these patients and studied by nested PCR amplification of the mitochondrial gene coding for the large subunit ribosomal RNA (mtLSUrDNA). The observed rate of colonization was higher than that reported in European populations. Genotypic characterization of the mtLSUrDNA locus revealed a predominance of the polymorphisms 85C/248C (genotype 1) and 85T/248C (genotype 3), with all samples possessing the wild-type genotype of dihydropteroate synthase. These findings suggest that cystic fibrosis patients could be an important reservoir and source of P. jirovecii infection. Further studies are required to elucidate the role of this common fungal colonization in the evolution of CF patients.

El ser humano como reservorio de Pneumocystis

Pneumocystis jirovecii, the fungal agent that causes Pneumocystis pneumonia (PCP), is known to exclusively infect humans. Molecular studies have enabled detection of this fungus in individuals who have been colonized by P. jirovecii. Such colonization, found in several populations, seems to act as a human reservoir for the fungus. Various studies have reported mutations associated with sulfa resistance in P. jirovecii strains isolated from colonized patients, who can transmit the mutant genotype to PCP-susceptible individuals. The growing interest in P. jirovecii colonization may prompt the design of new prevention and management strategies for PCP.

Pneumocystis jirovecii pneumonia in Latin America. A public health problem

Pneumocystis jirovecii pneumonia (PcP) is a well-recognized major opportunistic infection in HIV-infected patients. During the 1980s, the HIV pandemic turned PcP into a major worldwide medical and public health problem. With the introduction of Pneumocystis chemoprophylaxis and the development of highly active antiretroviral therapy (ART) for the treatment of HIV infection, there has been a decrease in PcP incidence in developed countries. However, the prevalence of AIDS-related PcP in developing countries remains high because a lot of people do not have access to ART or ignore their HIV infection status. This article discusses the information available about PcP among Latin American countries where there is a great regional heterogeneity in the prevalence of HIV infection and in ART coverage, as well as in the observed frequencies of PcP that range from 5.9 to 55% in this area.

Pneumocystis and Pneumocystosis: first meeting of experts from Latin-American and Portuguese-speaking countries – a mini-review

Pneumocystis e pneumocistose: 1 Encontro Ibero-americano e dos Países de Língua Oficial Portuguesa (Pneumocystis and Pneumocystosis: first meeting of experts from Latin-American and Portuguese-speaking countries) Lisbon, Portugal, 24–26 October 2013 The Pneumocystis and Pneumocystosis: first meeting of experts from Latin-American and Portuguese-speaking countries was held in Lisbon, Portugal, on 24–26 October 2013. A total of 20 speakers from Latin America, Africa and Europe participated in the meeting. The epidemiological studies presented in this meeting begin to change the misconception that since the AIDS epidemic, Pneumocystis pneumonia (PcP) has become an infrequent disease, showing that today PcP remains a major opportunistic infection in HIV-infected patients in both developed and developing countries and an emerging problem in immunocompromised patients without HIV infection worldwide. PcP management remains a challenge. Right now, the combination of caspofungin and trimethoprim-sulfamethoxazole (TMP-SMX) is a promising therapeutic approach that needs to be assessed in controlled clinical trials.