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1.
J Clin Microbiol ; 53(9): 2942-50, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26135875

ABSTRACT

Persons with hepatitis C virus (HCV) genotype 1a (GT1a) infections harboring a baseline Q80K polymorphism in nonstructural protein 3 (NS3) have a reduced virologic response to simeprevir in combination with pegylated interferon-alfa and ribavirin. We aimed to develop, validate, and freely disseminate an NS3 clinical sequencing assay to detect the Q80K polymorphism and potentially other HCV NS3 drug resistance mutations. HCV RNA was extracted from frozen plasma using a NucliSENS easyMAG automated nucleic acid extractor, amplified by nested reverse transcription-PCR, and sequenced using Sanger and/or next-generation (MiSeq) methods. Sanger chromatograms were analyzed using in-house software (RECall), and nucleotide mixtures were called automatically. MiSeq reads were iteratively mapped to the H77 reference genome, and consensus NS3 sequences were generated with nucleotides present at >20% called as mixtures. The accuracy, precision, and sensitivity for detecting the Q80K polymorphism were assessed in 70 samples previously sequenced by an external laboratory. A comparison of the sequences generated by the Sanger and MiSeq methods with those determined by an external lab revealed >98.5% nucleotide sequence concordance and zero discordant calls of the Q80K polymorphism. The results were both highly repeatable and reproducible (>99.7% nucleotide concordance and 100% Q80K concordance). The limits of detection (>2 and ∼5 log10 IU/ml for the Sanger and MiSeq assays, respectively) are sufficiently low to allow genotyping in nearly all chronically infected treatment-naive persons. No systematic bias in the under- or overamplification of minority variants was observed. Coinfection with other viruses (e.g., HIV and hepatitis B virus [HBV]) did not affect the assay results. The two independent HCV NS3 sequencing assays with the automated analysis procedures described here are useful tools to screen for the Q80K polymorphism and other HCV protease inhibitor drug resistance mutations.


Subject(s)
Antiviral Agents/pharmacology , Genotyping Techniques/methods , Hepatitis C, Chronic/virology , Mass Screening/methods , Mutation, Missense , Simeprevir/pharmacology , Viral Nonstructural Proteins/genetics , Drug Resistance , Hepacivirus/genetics , Hepacivirus/isolation & purification , Humans , Mutant Proteins/genetics , Reproducibility of Results , Sensitivity and Specificity
2.
Nature ; 491(7424): 444-8, 2012 Nov 15.
Article in English | MEDLINE | ID: mdl-23123857

ABSTRACT

Current global patterns of biodiversity result from processes that operate over both space and time and thus require an integrated macroecological and macroevolutionary perspective. Molecular time trees have advanced our understanding of the tempo and mode of diversification and have identified remarkable adaptive radiations across the tree of life. However, incomplete joint phylogenetic and geographic sampling has limited broad-scale inference. Thus, the relative prevalence of rapid radiations and the importance of their geographic settings in shaping global biodiversity patterns remain unclear. Here we present, analyse and map the first complete dated phylogeny of all 9,993 extant species of birds, a widely studied group showing many unique adaptations. We find that birds have undergone a strong increase in diversification rate from about 50 million years ago to the near present. This acceleration is due to a number of significant rate increases, both within songbirds and within other young and mostly temperate radiations including the waterfowl, gulls and woodpeckers. Importantly, species characterized with very high past diversification rates are interspersed throughout the avian tree and across geographic space. Geographically, the major differences in diversification rates are hemispheric rather than latitudinal, with bird assemblages in Asia, North America and southern South America containing a disproportionate number of species from recent rapid radiations. The contribution of rapidly radiating lineages to both temporal diversification dynamics and spatial distributions of species diversity illustrates the benefits of an inclusive geographical and taxonomical perspective. Overall, whereas constituent clades may exhibit slowdowns, the adaptive zone into which modern birds have diversified since the Cretaceous may still offer opportunities for diversification.


Subject(s)
Biodiversity , Birds/classification , Phylogeny , Animals , Birds/genetics , Birds/physiology
3.
Insect Mol Biol ; 20(6): 775-86, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21906194

ABSTRACT

We identified and characterized the activity of prolixicin, a novel antimicrobial peptide (AMP) isolated from the hemipteran insect, Rhodnius prolixus. Sequence analysis reveals one region of prolixicin that may be related to the diptericin/attacin family of AMPs. Prolixicin is an 11-kDa peptide containing a putative 21 amino acid signal peptide, two putative phosphorylation sites and no glycosylation sites. It is produced by both adult fat body and midgut tissues in response to bacterial infection of the haemolymph or the midgut. Unlike most insect antibacterial peptides, the prolixicin gene does not seem to be regulated by NF-κB binding sites, but its promoter region contains several GATA sites. Recombinant prolixicin has strong activity against the Gram-negative bacterium Escherichia coli and differential activity against several Gram-negative and Gram-positive bacteria. No significant toxicity was demonstrated against Trypanosoma cruzi, the human parasite transmitted by R. prolixus.


Subject(s)
Antimicrobial Cationic Peptides/immunology , Rhodnius/immunology , Amino Acid Sequence , Animals , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/genetics , Antimicrobial Cationic Peptides/isolation & purification , Bacteria/immunology , Base Sequence , Expressed Sequence Tags , Gene Expression Profiling , Molecular Sequence Data , Phylogeny , Promoter Regions, Genetic , Recombinant Proteins/immunology , Rhodnius/chemistry , Rhodnius/genetics , Trypanosoma cruzi/immunology
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