ABSTRACT
INTRODUÇAO: O vírus herpes simples (HSV) é dividido em dois sorotipos (HSV-1 e HSV-2) responsáveis, respectivamente, pelos herpes labial e genital. Embora a infeccão pelo HSV tenha um curso rápido, esse agente está freqüentemente relacionado a complicacões no tratamento de pacientes imunocomprometidos, como indivíduos transplantados, na condicão de agente oportunista. OBJETIVOS: Comparar e avaliar o uso de três técnicas atuais para diagnóstico de HSV em pacientes transplantados e não-transplantados. MATERIAL E MÉTODOS: Oitenta e quatro amostras clínicas consecutivas provenientes de 47 indivíduos transplantados e 37 não-transplantados foram coletadas de junho de 2001 a julho de 2002, sendo, simultaneamente, submetidas a nested multiplex reacão em cadeia da polimerase (PCR) (nmPCR), multiplex PCR (mPCR) e isolamento viral (IV) em células vero. RESULTADOS: Das amostras, 33,3 por cento (28/84) foram positivas para o HSV por IV, 34,5 por cento(29/84) por mPCR e 42,8 por cento (36/84) por nmPCR. Pela técnica de imunofluorescência direta (IFD), 85,7 por cento (24/28) das amostras foram caracterizadas como HSV-1, 86,2 por cento (25/29) pelo mPCR e 88,9 por cento(32/36) pelo nmPCR. Foram caracterizadas como HSV-2 pelas três técnicas empregadas 4,8 por cento(4/84) das amostras. Não houve diferenca significante de deteccão entre as técnicas de diagnóstico do HSV (p = 0,38), embora o nmPCR tenha detectado mais amostras de pacientes transplantados (p = 0,05). CONCLUSAO: Apesar do desempenho similar entre as técnicas, o nmPCR se mostrou ferramenta útil para pacientes transplantados ou para aqueles sob tratamento antiviral, onde é esperada baixa carga viral em suas amostras.
Subject(s)
Humans , Cell Culture Techniques , Clinical Laboratory Techniques , Herpes Simplex/diagnosis , Immunocompromised Host , Simplexvirus/isolation & purification , Transplantation , Fluorescent Antibody Technique , Polymerase Chain ReactionABSTRACT
The prevalence of mutations that confer resistance to antiretroviral drugs was examined in 56 drug-naive, human immunodeficiency virus type 1 (HIV-1)-infected individuals from the Army Health Service in Rio de Janeiro, Brazil. No primary protease inhibitor mutations were found, but secondary mutations were observed in 51.2% of the samples. Fourteen percent of the viruses had reverse transcriptase inhibitor-associated mutations. Comparative analysis of protease secondary mutations from four different time periods in drug-naive patients in the city of Rio de Janeiro has indicated constant rates for particular mutations. Changes in CD4 cell counts and HIV viral load over time in subtype B- and non-B-infected drug-naive patients were not significantly different.
Subject(s)
Acquired Immunodeficiency Syndrome/drug therapy , HIV-1/drug effects , Mutation , Adult , Base Sequence , Drug Resistance, Viral , Female , HIV Envelope Protein gp41/genetics , HIV Protease/genetics , HIV Reverse Transcriptase/genetics , HIV-1/classification , Humans , Male , Military Personnel , Molecular Sequence DataABSTRACT
OBJECTIVE: To study the prevalence of HIV drug resistance mutations and subtype distribution in a Brazilian drug-naive population. Asymptomatic, drug-naive HIV-1-infected individuals were targeted in 13 voluntary counseling and testing centers spread around the country. METHODS: Plasma viral RNA was extracted from 535 HIV-1-positive subjects. Protease (PR) and reverse transcriptase (RT) genomic regions were sequenced for subtype determination and analysis of drug resistance mutations. RESULTS: Eight samples (2.24 %) showed primary mutations related to protease inhibitor (PI) resistance, eight (2.36%) to nucleoside reverse transcriptase inhibitors (NRTI) and seven (2.06%) to non-nucleoside reverse transcriptase inhibitors (NNRTI). Accessory mutations were found in the PR gene at the following positions: L63P/V/T/A/I [153/345 (44.3%)], M36I/L [149/345 (43.2%)], L10I/F/V [82/345 (23.8%)], V77I [60/345 (17.4%)], A71V/T [11/345 (3.2%)], K20M/R [10/345 (2.9%)], and V82I [4/345 (1.2%)]. Mutations known to be associated with reduced sensitivity to NRTI or NNRTI (V118I, E44D, K219R, T69A, and V75L) were found in a low prevalence (0.6-2.4%). A high proportion of the isolates from subtype C was found in the southern states. Subtype F-related viruses were the main non-B variant in the rest of the country. CONCLUSIONS: Brazil has a low prevalence of drug-resistant strains circulating among recently diagnosed individuals. However, there was an increase in these rates compared with similar studies performed with samples collected in Brazil from 1996 to 1998. Continued surveys are required to detect trends in these rates, but routine genotypic testing in the drug-naive population prior to antiretroviral initiation is not required in Brazil.
Subject(s)
Drug Resistance, Viral/genetics , HIV Infections/drug therapy , Mutation/genetics , Adult , Brazil/epidemiology , Chronic Disease , Female , Genotype , HIV Infections/epidemiology , HIV Infections/genetics , Humans , Male , Middle Aged , Prevalence , Risk FactorsABSTRACT
OBJECTIVE: To characterize the subtype C strains of HIV type 1 that circulate in Brazil, especially those originated from the southern part of the country. DESIGN AND METHODS: One hundred and twelve HIV-1-positive subjects had their plasma viral RNA extracted. Protease (PR) and reverse transcriptase (RT) genomic regions were polymerase chain reaction-amplified and sequenced for subtype determination. Subtype C strains were selected and compared to other strains of this subtype from the database, and specific amino acid signature patterns were searched. RESULTS: Brazilian subtype C viruses form a very strong monophyletic group when compared to subtype C viruses from other countries and presented specific signature amino acids. Recombinants between subtype C and B viruses have been documented in areas of co-circulation. The incidence of primary PR and RT inhibitor resistance mutations in drug-naïve subjects was observed. An increasing number of secondary resistance mutations was also seen, some of which are characteristic of subtype C-related sequences. CONCLUSIONS: Introduction of subtype C of HIV-1 in Brazil was likely a single event of one or a mixture of similarly related strains. Recombination between subtype C and B viruses is an ongoing process in the country. Primary and secondary drug resistance mutations were observed, although some of the secondary mutations could be associated with subtype C molecular signatures. Subtype-specific polymorphisms of PR and RT sequences found in this subtype C Brazilian variant might influence this emergence and have an impact on HIV treatment and on vaccine development in the country.
