Chee-Keng Mok

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Position-specific entropy profiles created from scanning 306 human and 95 avian influenza A viral genomes showed that 228 of 4591 amino acid residues yielded significant differences between these 2 viruses. We subsequently used 15,785 protein sequences from the National Center for Biotechnology Information (NCBI) to assess the robustness of these signatures(More)
Taiwan suffered from the outbreak of severe acute respiratory syndrome (SARS) in 2003. Our laboratory performed a series of virology and serology tests for SARS patients admitted to our hospital. Cross-reactivity was found when testing for antibody against human T-cell lymphotropic virus (HTLV) in one patient with SARS. Therefore, antibodies against HTLV(More)
Infections of the novel avian influenza A H7N9 virus cause severe respiratory diseases and death. In this study, to develop highly sensitive methods for differentially detecting the H7N9 virus, multiplex and singular real-time reverse transcription polymerase chain reaction (RT-PCR) assays were established and examined by targeting the H7 and N9 genes of(More)
A laboratory-based surveillance network of 11 clinical virological laboratories for influenza viruses was established in Taiwan under the coordination of the Center for Disease Control and Prevention (CDC), Taiwan. From October 2000 to March 2004, 3,244 influenza viruses were isolated, including 1,969 influenza A and 1,275 influenza B viruses. The influenza(More)
BACKGROUND The 2009 influenza A pandemic virus (H1N1(pdm)) may reassort with old seasonal influenza A virus (H1N1₁₄₁) in humans and potentially change their pathogenicity. METHODS AND RESULTS This study focuses on the reassortment of ribonucleoproteins (RNPs) among H1N1(pdm) and seasonal influenza A viruses. A single RNP gene reassortment altered reporter(More)
Neuraminidase (NA) is a homotetramer viral surface glycoprotein that is essential for virus release during influenza virus infections. Previous studies have not explored why influenza NA forms a tetramer when the bacterial monomer NA already exhibits excellent NA enzymatic activity levels. In this study, we focused on 28 highly conserved residues among all(More)
Prompt diagnosis of an oseltamivir-resistant marker is important for patient management, in particular to prevent the spread of resistant strains in the recent human H7N9 outbreak. We tailored a pyrosequencing assay to reveal neuraminidase R292K, a resistant marker found in one isolate from China, and demonstrated its performance in both sensitivity and(More)
Recombination plays an important role in shaping the genetic diversity of a number of DNA and RNA viruses. Although some recent studies have reported bioinformatic evidence of mosaic sequences in a variety of influenza A viruses, it remains controversial as to whether these represent bona fide natural recombination events or laboratory artifacts.(More)
BACKGROUND/PURPOSE Some isolated influenza strains are untypable. The possibility that a novel and potentially lethal strain, such as H5 virus, might be one of these untypable strains remains a major concern. This study investigated the nature of untypable influenza strains in Taiwan. METHODS Subtyping for unsubtyped isolates was conducted by reverse(More)
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