Prevalence of resistance-associated mutations in Human Immunodeficiency Virus type 1-positive individuals failing HAART in Rio de Janeiro, Brazil

We investigated the occurrence of HIV-1 antiretroviral resistance in individuals failing to respond to highly active antiretroviral therapy (HAART) attended by RENAGENO from 2001-2004. One hundred and seventeen patients were selected for this study; their plasma viral RNA was extracted and the PR and RT genes sequenced to examine subtype, genetic polymorphisms and mutations associated with resistance to antiretroviral drugs. HIV-1 sequence analysis showed that 86/100 (86 percent) were infected with subtype B, 7/100 (7 percent) with subtype F and 7/100 (7 percent) with RT/PR hybrid forms (2 D/B, 2 F/B, 2 B/F and 1 D/F). In 14 (12 percent) of the samples, the subtype was not determined. The prevalence of resistance mutations was high (93.1 percent), mainly in the RT gene. The most prevalent resistance mutations were: M184V (60.7 percent), T215Y (49.6 percent) and M41L (46.7 percent) in the RT gene and L90M (19.6 percent), M46I (16.2 percent) and D30N (12.8 percent) in the PR gene. The frequency of resistance mutations tended to increase from the first to the second therapeutic scheme failure (p=0.079); but it stabilized after subsequent failures (p=0.875). Our finding of a high frequency of drug resistant HIV-1 samples supports the need for continuous genotypic monitoring of patients failing HAART.

Prevalence of resistance-associated mutations in human immunodeficiency virus type 1-positive individuals failing HAART in Rio de Janeiro, Brazil.

We investigated the occurrence of HIV-1 antiretroviral resistance in individuals failing to respond to highly active antiretroviral therapy (HAART) attended by RENAGENO from 2001-2004. One hundred and seventeen patients were selected for this study; their plasma viral RNA was extracted and the PR and RT genes sequenced to examine subtype, genetic polymorphisms and mutations associated with resistance to antiretroviral drugs. HIV-1 sequence analysis showed that 86/100 (86%) were infected with subtype B, 7/100 (7%) with subtype F and 7/100 (7%) with RT/PR hybrid forms (2 D/B, 2 F/B, 2 B/F and 1 D/F). In 14 (12%) of the samples, the subtype was not determined. The prevalence of resistance mutations was high (93.1%), mainly in the RT gene. The most prevalent resistance mutations were: M184V (60.7%), T215Y (49.6%) and M41L (46.7%) in the RT gene and L90M (19.6%), M46I (16.2%) and D30N (12.8%) in the PR gene. The frequency of resistance mutations tended to increase from the first to the second therapeutic scheme failure (p=0.079); but it stabilized after subsequent failures (p=0.875). Our finding of a high frequency of drug resistant HIV-1 samples supports the need for continuous genotypic monitoring of patients failing HAART.

Human immunodeficiency virus type 1 protease and reverse transcriptase mutation patterns among treatment-naive patients in different stages of infection in Rio de Janeiro, Brazil.

The presence of genetic mutations in HIV-1-positive untreated individuals and its contribution to treatment failure, either in an individual or on a population basis, remains an important concern. The goal was to analyze and compare HIV-1 reverse transcriptase (RT) and protease (PR) genes of untreated individuals with chronic and recent infections. Fifty-one chronic infected individuals for whom initiation of antiretroviral treatment had been recommended and 20 individuals with recent documented HIV-1 seroconversion had their plasma viral RNA extracted and the PR and RT genes sequenced in order to determine subtype, presence of genetic polymorphisms and mutations associated with resistance to antiretroviral drugs. All 20 recent seroconvertors were infected with subtype B viruses. Of the 51 chronically infected patients, 40 (78.4%), 7 (13.7%), and 2 (3.9%) were infected with subtypes B, F, and C, respectively. Two (3.9%) hybrid forms were also observed in two individuals with chronic infection: D/B and D/F. Despite seroconversion stage, type and quantity of mutations were similar to both groups (P = 0.961). This group also presented the only (1.4%) drug-resistance mutation (M184V) among all samples investigated. In summary, the present study shows a high occurrence of equivalent polymorphisms unrelated to drug resistance in samples collected from untreated HIV-1- infected individuals in different seroconversion status, and suggests low primary resistance mutations. Results also indicate that non-B subtypes circulating in Rio de Janeiro have specific Brazilian non-synonymous mutations.

Prevalence of mutations related to HIV-1 antiretroviral resistance in Brazilian patients failing HAART.

BACKGROUND: Current guidelines for antiretroviral (ARV) therapy recommend at least triple-drug combination, the so-called highly active antiretroviral therapy (HAART). Not all patients respond to HAART and the development of drug resistance remains one of the most serious obstacles to sustained suppression of HIV. OBJECTIVE: In an attempt to correlate the HIV therapeutic failure with reverse transcriptase (RT) and protease resistance mutations, we describe the ARV resistance profile in patients failing HAART in Brazil. We studied 267 Brazilian HIV-1 infected patients failing HAART looking for mutations in RT and protease genes. The mutation profile of the viruses infecting these individuals were deduced and correlated to laboratorial parameters. STUDY DESIGN: Two different HIV-1 genomic regions were targeted for PCR amplification, the protease (pro) and pol RT (palm finger region) genes. The mutations related to drug resistance in RT gene was analyzed using a line probe assay (LIPA(R)) and pro amino acids positions 82 and 90 were screened through RFLP using HincII restriction digestion. RESULTS: There was strong correlation between the mutation in the pro and RT genes and therapeutic failure. The main mutation found in RT gene was the M184V (48%) followed by T69D/N (47%), T215Y/F (46%), M41L (39%), and L74V (7%). In the pro gene the main mutation found was L90M (26%) followed by dual substitution in L90M and V82A (6%). All mutations profiles matched very well with the patients drug regimen. CONCLUSIONS: This study has shown that 84.7% of HIV infected subjects failing HAART for more than 3 months presented viral genomic mutations associated with drug resistance.

Germinação e vigor de sementes de goiaba (Psidium guajava L. ) submetidas a métodos para superação da dormência / Germination and vigor of guava seeds (Psidium guajava L. ) submitted to different methods to supress dormancy

Este trabalho teve como objetivo testar a germinação e o índice de velocidade de germinação em sementes de goiaba (Psidium guajava L.). As sementes foram obtidas de frutos maduros provenientes de um pomar comercial, localizado no município de Pelotas/RS. O experimento foi conduzido no Laboratório Didático de Análise de Sementes, pertencente ao Departamento de Fitotecnia da FAEM/UFPel. Os tratamentos aplicados às sementes foram: a) estratificação durante 0, 10, 20, 30 dias em geladeira, com temperatura em tomo de 5°C; b) escarificação com ácido sulfúrico concentrado, com imersão por -15 minutos e com areia média de lavada, atritando-se as sementes igualmente por 15 minutos. O experimento foi conduzido com delineamento experimental completamente casualizado, com 4 repetições de 50 sementes. Após os tratamentos as sementes foram colocadas em substratos papel e areia e postas a germinar em dois ambientes distintos: germinador a temperatura constante de 25 °C e sob temperatura ambiente. A germinação ocorreu entre 8 e 11 dias no germinador. O substrato só teve efeito significativo para a variável germinação, sendo que em areia houveram maiores médias de germinação. O melhor tratamento de escarificação, para ambas variáveis, foi com areia. O tratamento de estratificação teve efeito negativo sobre a germinação e positivo sobre o índice de velocidade de germinação de sementes de goiaba.

This work was conducted to study the germination test and the germination speed rate of guava seeds (Psidium guajava L.). Guava seeds were coilected from ripe fruits of a commercial orchard in Pelotas, RS. The experiment was carried out at the Seed Analysis Laboratory/ Plant Science Department - FAEM/UFPel. The seed treatments used were: a) refrigerated stratification around 5°C during 0, 10, 20, and 30 days; b) concentrated sulfuric acid scarification through 15 minutes immersion and medium washed sand seeds attrition during 15 minutes. The experimental design was a completely randomized with 4 replications of 50 seeds. After each seed treatment, seeds were placed in the paper and sand substratos: germinator chamber at constant 25°C and at room temperature. The germination occurred between 8 and 11 days in the germinator chamber. The substrate showed significativo effect only for germination and sand showed higher germination average values. Sands was the best scarification treatment for both situations. The stratification treatment decreased the germination and increased the germination speed rate of guava seeds.