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Instituto de Higiene e Medicina Tropical

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2013

Viral phylogeny in court: The unusual case of the Valencian anesthetist

A large and complex outbreak of hepatitis C virus in Valencia, Spain that began 25 years ago led to the prosecution and conviction of an anesthetist who was accused of infecting hundreds of his patients. Evolutionary analyses of viral gene sequences were presented as evidence in the trial, and these are now described in detail by González-Candelas and colleagues in a paper published in BMC Biology. Their study illustrates the challenges and opportunities that arise from the use of phylogenetic inference in criminal trials concerning virus transmission.
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HIV-1 subtype is an independent predictor of reverse transcriptase mutation k65r in HIV-1 patients treated with combination antiretroviral therapy including tenofovir

Subtype-dependent selection of HIV-1 reverse transcriptase resistance mutation K65R was previously observed in cell culture and small clinical investigations. We compared K65R prevalence across subtypes A, B, C, F, G, and CRF02_AG separately in a cohort of 3,076 patients on combination therapy including tenofovir. K65R selection was significantly higher in HIV-1 subtype C. This could not be explained by clinical and demographic factors in multivariate analysis, suggesting subtype sequence-specific K65R pathways.
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Decreasing population selection rates of resistance mutation K65R over time in HIV-1 patients receiving com- bination therapy including tenofovir

The use of tenofovir is highly associated with the emergence of mutation K65R, which confers broad resistance to nucleoside/nucleotide analogue reverse transcriptase inhibitors (NRTIs), especially when tenofovir is combined with other NRTIs also selecting for K65R. Although recent HIV-1 treatment guidelines discouraging these combinations resulted in reduced K65R selection with tenofovir, updated information on the impact of currently recommended regimens on the population selection rate of K65R is presently lacking.
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HIV-1 sub- type distribution and its demographic determinants in newly diagnosed patients in Europe suggest highly compartmentalized epidemics

Understanding HIV-1 subtype distribution and epidemiology can assist preventive measures and clinical decisions. Sequence variation may affect antiviral drug resistance development, disease progression, evolutionary rates and transmission routes.
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A genomic signature and the identification of new sporulation genes

Bacterial endospores are the most resistant cell type known to humans, as they are able to withstand extremes of temperature, pressure, chemical injury, and time. They are also of interest because the endospore is the infective particle in a variety of human and livestock diseases.
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Monoclonal antibody technology applied to the detection of Cryptosporidium parvum oocysts in human and cattle fecal samples

With the discovery that the coccidian parasiteCryptosporidium sp. can cause severe symptoms in humans, many diagnostic techniques were quickly implemented such as microscopic visualization, immunofluorescence and PCR. Currently, there is no effective drug treatment and none of the current diagnostic methods is 100% accurate. In this study, a BALB/C mouse was subcutaneously immunized with Cryptosporidium parvum oocysts extract.
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Genotypic diversity of environmental Cryptococcus neoformans isolates from Northern Portugal

The Cryptococcus neoformans/C. gattii species complex members are the main agents of systemic cryptococcosis. This disease is believed to be acquired from the environment via fungal cell inhalation. Often, isolates recovered from environmental and clinical sources have proven to be genotypically similar. We assessed the occurrence of C. neoformans and C. gattii in environmental substrates collected in a Portuguese region.
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