Pneumocystis jirovecii dihydropteroate synthase genotypes in French patients with pneumocystosis: a 1998-2001 prospective study.

Dihydropteroate synthase gene (DHPS) mutations at codons 55 and 57 have been associated with sulfa/sulfone resistance in Pneumocystis jirovecii strains from patients who previously received prophylaxis. To evaluate the prevalence of these mutations, a portion of P. jirovecii DHPS gene was analysed using PCR combined with restriction fragment length polymorphism (RFLP) analysis in 92 bronchoalveolar fluid samples collected between January 1998 and September 2001 from French patients with pulmonary pneumocystosis (PCP). Seventy-six samples contained the wild-type DHPS genotype (82.6%) and 16 contained a mutant genotype (17.4%). Twelve out of the 16 isolates with a mutant DHPS genotype corresponded to patients who had never received sulfa or sulfone prophylaxis, suggesting that DHPS mutants may be acquired de novo. There was no significant difference in favourable or adverse outcome in PCP caused by the wild or mutant DHPS genotypes (P = 0.34).

Identification of Pneumocystis carinii f. sp. hominis gene sequences in filtered air in hospital environments.

To evaluate the risk of a nosocomial spread of Pneumocystis carinii f. sp. hominis (P. carinii hominis), air filter samples from rooms of P. carinii pneumonia (PCP) patients, adjacent corridors, and other hospital environments have been investigated for the presence of P. carinii hominis. Amplified DNA from air filters and sputum or bronchoalveolar lavage samples from the PCP patients have been genotyped with the P. carinii hominis genes of the mitochondrial large-subunit (mtLSU) rRNA and the internal transcribed spacers (ITS1 and ITS2) of the rRNA. Genotypes of the two loci were identified by direct sequencing, and for site 85 of the mtLSU locus, three allele-specific PCR assays were used. P. carinii hominis DNA was identified in the air of five of seven PCP patient rooms and in the air of two of four air filtrations from the ward corridors. The P. carinii hominis genotypes were the same in four of the five room air samples as those in the corresponding patients, suggesting a risk of person-to-person transmission of P. carinii hominis from PCP patients. Three of 16 air samples collected in infectious disease wards without the presence of PCP patients and one sample from a cardiology unit in a separate hospital building were also positive, which further strengthens the possibility of acquisition of P. carinii hominis from the environment.

Study of internal transcribed spacer and mitochondrial large-subunit genes of Pneumocystis carinii hominis isolated by repeated bronchoalveolar lavage from human immunodeficiency virus-infected patients during one or several episodes of pneumonia.

The objective of this study was to type, analyze, and compare Pneumocystis carinii hominis strains obtained from different samples during a given or recurrent episodes of P. carinii pneumonia (PCP) for epidemiologic purposes. We studied 36 bronchoalveolar lavage (BAL) or induced sputum (IS) samples from 16 human immunodeficiency virus-infected patients with one or several episodes of PCP. PCR amplification and direct sequencing were performed on the two internal transcribed spacers (ITS1 and ITS2) of P. carinii hominis rRNA genes by using DNA extracted from BAL or IS samples, and the sequences were compared to the mitochondrial large-subunit (mt LSU) gene sequence determined in a previous study in our laboratory. The studies of the mt LSU and ITS sequences showed that some patients (n = 10) were infected with the same strains of P. carinii hominis during a given episode of PCP. In one patient infected with strains with identical sequences in several episodes, the recurrence could have been due to reactivation of organisms not eliminated by treatment during the first episode or to de novo infection by an identical strain. In five patients infected with strains with different sequences in each episode, recurrence was due to de novo infection. Sequence analysis of these two P. carinii hominis gene regions showed that de novo infection can occur in AIDS patients with recurrent PCP.

Biodiversity of Pneumocystis carinii hominis: typing with different DNA regions.

The purpose of this study was to identify the most useful gene for the detection of biodiversity of Pneumocystis carinii hominis isolates and to compare samples from French and Italian subjects. We studied 20 bronchoalveolar lavage fluid specimens from 20 human immunodeficiency virus-infected patients (10 French and 10 Italian patients) with Pneumocystis carinii pneumonia by DNA sequencing of the thymidylate synthase (TS), 5S rRNA, large-subunit mitochondrial rRNA (mt LSU rRNA), and internal transcribed spacer (ITS1 and ITS2) genes. Thirteen of the 20 sequenced samples had the prototype TS gene sequence. Fourteen of the 20 samples showed the prototype sequence of the 5S rRNA gene, and 6 had variant sequences of the 5S rRNA gene. The mt LSU rRNA gene was sequenced for 18 of the 20 samples; all sequences were different from the prototype sequence and were classified into four groups. Thirteen of the 20 ITS1 and ITS2 sequences were analyzed, and all the sequences were found to be different from the prototype sequence and were classified into 10 groups. The internal transcribed spacer regions thus appear to be the most discriminatory region of DNA for analysis of the biodiversity of P. carinii hominis isolates.

Preliminary results of Pneumocystis carinii strain differentiation by using molecular biology.

The mode of Pneumocystis carinii transmission is controversial. Recent studies point to exogenous inoculation rather than reactivation, and person-to-person transmission has also been suggested. Comparison of nucleotide sequences of the large-subunit mitochondrial rRNA gene of P. carinii from human immunodeficiency virus-seropositive patients showed strain differences.

[Transnationalization, the development crisis and the end of the Third World]. / La transnationalisation, la crise du developpement et la fin du Tiers Monde.

PIP: This work argues that transnational corporations, by their internal dynamics, disturb the pace of development in Third World countries. There is little consensus on what should constitute a national economy, despite the fact that the idea of economic nationalism has a long history. The concept that a geographic area should show a minimal degree of economic vitality as a condition for emergence into a nation state is largely foreign to political scientists and politicians. Similarly, economists do not base their analyses on nations. The developed western countries between about 1950-80 to some extent became models of national economies. Their economic complexity, strong interdependence between economic sectors, and developed industrial infrastructures were seen as the necessary complements of national sovereignty. But the most important factor in economic growth and development, capital, by its very nature is not tied to any country. The dynamics of capital of transnational firms, and more generally the movement of modern economy and society, tend to destroy the sense of economic nationality. The deterritorialization of the economy is not limited to growth of transnational firms. Such arrangements as joint ventures, licensing contracts, and agreements to share production blur the lines between nation states. Deterritorialization affects culture and power relations as well as economics. The Third World as a conceptual entity is destined to come to an end not only because of the transnationalization of productive processes and financial circuits but because of internal cleavages. The factors originally believed to be common to Third World countries have not proven to be as enduring as once thought. The ideology of a unified Third World has crumbled in the face of internal conflicts, the powerlessness of the Organization of African Unity, the rise of Islamic fundamentalism, and other forces. The great division between countries is not fundamentally into 3 but into 2: the developed and the underdeveloped. The impact of multinationals on development in the Third World is likely to include both increasing homogenization due to the weakening of state borders and increasing differentiation, which is the traditional consequence of capital accumulation. The growth in importance of services and the development of the informal sector are 2 exceptions that may avoid the impact of transnational firms.^ieng