ABSTRACT
The annotation and comparative analyses of the genomes of Mycoplasma synoviae and Mycoplasma hyopneumonie, as well as of other Mollicutes (a group of bacteria devoid of a rigid cell wall), has set the grounds for a global understanding of their metabolism and infection mechanisms. According to the annotation data, M. synoviae and M. hyopneumoniae are able to perform glycolytic metabolism, but do not possess the enzymatic machinery for citrate and glyoxylate cycles, gluconeogenesis and the pentose phosphate pathway. Both can synthesize ATP by lactic fermentation, but only M. synoviae can convert acetaldehyde to acetate. Also, our genome analysis revealed that M. synoviae and M. hyopneumoniae are not expected to synthesize polysaccharides, but they can take up a variety of carbohydrates via the phosphoenolpyruvate-dependent phosphotransferase system (PEP-PTS). Our data showed that these two organisms are unable to synthesize purine and pyrimidine de novo, since they only possess the sequences which encode salvage pathway enzymes. Comparative analyses of M. synoviae and M. hyopneumoniae with other Mollicutes have revealed differential genes in the former two genomes coding for enzymes that participate in carbohydrate, amino acid and nucleotide metabolism and host-pathogen interaction. The identification of these metabolic pathways will provide a better understanding of the biology and pathogenicity of these organisms.
ABSTRACT
In the context of universal access to antiretroviral therapy, the surveillance of human immunodeficiency virus type 1 (HIV-1) genetic diversity and resistance becomes pivotal. In this work our purpose was to describe the genetic variability; prevalence of drug-resistance mutations; and genotypic resistance profiles in HIV-1 infected individuals under antiretroviral treatment, from the Federal District, Brasília, Central Brazil. The entire viral protease and codons 19 to 234 of the reverse transcriptase gene from 45 HIV-1 isolates were amplified and sequenced for subtyping and genotyping. By phylogenetic analysis, 96 percent of the samples clustered with subtype B and the remaining 4 percent with HIV-1 subtype F sequences. One major protease inhibitor resistance-associated mutation, I50V, was detected in 38 percent of the samples. Minor mutations were also found at the protease gene: L10I/V (7 percent), K20M (2 percent), M36I (11 percent), L63P (20 percent), A71T (2 percent), and V77I (7 percent). Many mutations associated with reduced susceptibility to nucleoside or non-nucleoside reverse transcriptase inhibitors were detected: M41L (11 percent), E44D (4 percent), D67N (11 percent), T69D (2 percent), K70R (11 percent), L74V (2 percent), L100I (4 percent), K103N (18 percent), V118I (9 percent), Y181C (11 percent), M184V (18 percent), G190A (4 percent), T215Y (4 percent), and K219E (4 percent). This study has shown that 84 percent of the studied population from the Federal District, showing evidences of therapy failure, presented viral genomic mutations associated with drug resistance. The main antiretrovirals to which this population showed resistance were the PI amprenavir (38 percent), the NNRTIs delavirdine, nevirapine (31 percent), and efavirenz (24 percent), and the NRTIs lamivudine (18 percent), abacavir, and zidovudine (13 percent).
Subject(s)
Humans , Anti-HIV Agents , Drug Resistance, Viral , HIV Infections , HIV-1 , Antiretroviral Therapy, Highly Active , Brazil , Genetic Variation , Genotype , HIV Reverse Transcriptase , Mutation , Polymerase Chain Reaction , RNA, Viral , Viral LoadABSTRACT
We report the prevalence of human papillomavirus type 16 (HPV-16) variants in women with cervical lesions from the Federal District, Central Brazil. We analyzed 34 HPV-16 samples, identifying the sequence variations of E6 and L1 genes and correlating variant frequency with disease status. The most prevalent HPV-16 variant was the European (50 percent), followed by Asian-American (41.2 percent), African-1 (5.9 percent), and African-2 (2.9 percent). European and non-European variants appeared in equal frequencies among the cytological types of lesions - atypical squamous or glandular cells of undetermined significance, cytological alterations suggesting HPV infection, cervical intraepithelial neoplasias, squamous cell carcinoma, and adenocarcinoma.