In vivo emergence of drug-resistant mutations at less than 50 HIV-1 RNA copies/mL that are maintained at viral rebound in longitudinal plasma samples from human immunodeficiency virus type-1-infected patients on highly active antiretroviral therapy.

OBJECTIVE: Emergence of human immunodeficiency virus type-1 (HIV-1) genotypic drug resistance is generally attributed to noncompliance, poorly absorbed drugs, or drug-to-drug interaction. Attempts to determine emerging genotypic drug resistance from study subjects on highly active antiretroviral therapy (HAART) relied on insensitive polymerase chain reaction (PCR) techniques, revealing wild type HIV-1 or precursor resistant genotypes from few plasma samples successfully amplified with <50 copies/mL. STUDY DESIGN/METHODS: In this analysis, using Applied Biosystems' ViroSeq HIV-1 Genotyping Systems, Version 2.0 (Applied Biosystems, Foster City, CA, USA) and the supplemental, for research use only, nested PCR primers, genotypic drug resistance was determined in longitudinal plasma samples from 11 study subjects on HAART. RESULTS: In 4 of 11 study subjects, newly emerging genotypic primary resistant mutations were detected in plasma samples with <50 copies/mL. Most of these primary drug-resistant mutations were detected in subsequent longitudinal samples with detectable viral load (viral breakthrough). CONCLUSIONS: This analysis suggests sufficient viral replication <50 copies/mL to generate genotypic drug resistance in study subjects on suppressive HAART.

[Coccidioides immitis: isolation from soil samples in San Luis and Mendoza provinces]. / Coccidioides immitis: su aislamiento de muestras de suelos de las provincias de San Luis y Mendoza

By using the double pour plate method, Yeasts Extract Agar (YE) which contained a high concentration of chloramphenicol-streptomycin sulfate and cycloheximide,, and by inoculating mice intraperitoneally, we succeed in the isolation of different strains of Coccidicides immitis from 12 samples of the soils collected in the province of San Luis and from 1 of the province of Mendoza (Argentina), a 70% of the samples turned out positive. Identification of the strains was based on macro- and micro-morphology of the colonies, pathogenicity for mice and the capacity to transform in shaked cultures.