Research and Diagnostic Center

Taipei, Taiwan

Research and Diagnostic Center

Taipei, Taiwan
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Kuo C.C.,Research and Diagnostic Center | Kuo C.C.,University of California at Davis | Huang C.L.,Research and Diagnostic Center | Wang H.C.,Research and Diagnostic Center
Medical and Veterinary Entomology | Year: 2011

Scrub typhus and tick-borne spotted fever group (SFG) rickettsioses are transmitted by chiggers (larval trombiculid mites) and hard ticks, respectively. We assessed exposure to these disease vectors by extensively sampling both chiggers and ticks and their small mammal hosts in eastern Taiwan during 2007 and 2008. The striped field mouse Apodemus agrarius Pallas (Rodentia: Muridae) was the most common of the small mammals (36.1% of 1393 captures) and presented the highest rate of infestation with both chiggers (47.8% of 110 760) and ticks (78.1% of 1431). Leptotrombidium imphalum Vercammen-Grandjean & Langston (Trombidiformes: Trombiculidae) and immature Rhipicephalus haemaphysaloides Supino (Ixodida: Ixodidae) were the most abundant chiggers (84.5%) and ticks (>99%) identified, respectively. Immunofluorescent antibody assay revealed high seropositive rates of rodents against Orientia tsutsugamushi Hyashi (Rickettsiales: Rickettsiaceae), the aetiological agent of scrub typhus (70.0% of 437 rodents), and tick-borne SFG rickettsiae (91.9% of 418 rodents). The current study represents a first step towards elucidating the potential hosts and vectors in the enzootic transmission of O. tsutsugamushi and tick-borne SFG rickettsiae in Taiwan. Further studies should focus on characterizing pathogens in L. imphalum and R. haemaphysaloides, as well as the proclivity of both vectors to humans. Uncovering the main hosts of adult ticks is also critical for the prevention of SFG rickettsial infections. © 2011 The Authors. Medical and Veterinary Entomology © 2011 The Royal Entomological Society.

Liao T.-L.,Academia Sinica, Taiwan | Liao T.-L.,National Taiwan University | Liao T.-L.,Research and Diagnostic Center | Wu C.-Y.,Academia Sinica, Taiwan | And 6 more authors.
EMBO Journal | Year: 2010

Influenza A virus RNA replication requires an intricate regulatory network involving viral and cellular proteins. In this study, we examined the roles of cellular ubiquitinating/deubiquitinating enzymes (DUBs). We observed that downregulation of a cellular deubiquitinating enzyme USP11 resulted in enhanced virus production, suggesting that USP11 could inhibit influenza virus replication. Conversely, overexpression of USP11 specifically inhibited viral genomic RNA replication, and this inhibition required the deubiquitinase activity. Furthermore, we showed that USP11 interacted with PB2, PA, and NP of viral RNA replication complex, and that NP is a monoubiquitinated protein and can be deubiquitinated by USP11 in vivo. Finally, we identified K184 as the ubiquitination site on NP and this residue is crucial for virus RNA replication. We propose that ubiquitination/deubiquitination of NP can be manipulated for antiviral therapeutic purposes. © 2010 European Molecular Biology Organization.

Huang W.-L.,Research and Diagnostic Center | Hsu Z.-J.,Research and Diagnostic Center | Chang T.C.,National Cheng Kung University | Jou R.,Research and Diagnostic Center | Jou R.,National Yang Ming University
Clinical Microbiology and Infection | Year: 2014

To rapidly detect rifampin, isoniazid and multidrug resistance in Mycobacterium tuberculosis isolates, a new system (BluePoint MtbDR, Bio Concept Inc., Taichung, Taiwan) including an oligonucleotide array and an automatic reader was evaluated. The array simultaneously identifies M. tuberculosis and predominant mutations in the rpoB, katG and inhA upstream regulatory region (inhA-r) genes. The system was assessed with 324 clinical M. tuberculosis isolates, including 210 multidrug-resistant, 41 rifampin mono-resistant, 34 isoniazid mono-resistant and 39 fully susceptible isolates. The results were compared with those obtained using the GenoType MTBDRplus test, drug-resistant gene sequencing and conventional drug susceptibility testing. The detection limit of the array was 25 pg DNA. The array and the GenoType MTBDRplus test detected 179 (85.2%) and 182 (86.7%) multidrug-resistant M. tuberculosis strains, respectively. The sensitivities of the array for detecting rifampin and isoniazid resistance were 98.4% and 87.7%, respectively, whereas the sensitivities of the GenoType MTBDRplus test for detecting rifampin and isoniazid resistance were 98.8% and 88.9%, respectively. No significant difference was found between the tests with respect to their sensitivities to detect multidrug resistance (p 0.66), rifampin resistance (p 0.69) or isoniazid resistance (p 0.68). The discrepancies were mainly attributed to rare mutations in inhA-r, which were not included in the array. The array can directly reveal transmission-associated mutations, which are useful for epidemiological investigations. The turnaround time of the array test was 6-7 h. This study confirms the feasibility of using this system for rapid and accurate diagnosis of isoniazid and rifampin resistance in M. tuberculosis. © 2013 The Authors.

Hung C.-C.,National Yang Ming University | Chang S.-Y.,National Yang Ming University | Ji D.-D.,National Yang Ming University | Ji D.-D.,Research and Diagnostic Center
The Lancet Infectious Diseases | Year: 2012

Entamoeba histolytica infection (amoebiasis) is the second leading cause of death from parasitic diseases. Epidemiological studies from developed countries have reported an increasing prevalence of amoebiasis and of invasive infections, such as amoebic colitis, among men who have sex with men (MSM) who engage in oral-anal sex. Although most infections with E histolytica are asymptomatic, clinical manifestations of invasive amoebiasis mainly include amoebic colitis and amoebic liver abscess, which are associated with substantial morbidity and medical cost. Laboratory diagnosis of amoebiasis should be based on detection of E histolytica by use of tests with high sensitivity and specificity, such as specific amoebic-antigen or PCR-based assays. Microscopy used in routine clinical laboratories is not sensitive or specific enough for detection of E histolytica. Metronidazole or tinidazole remains the mainstay of treatment for invasive amoebiasis, followed by treatment with luminal agents to prevent relapse and transmission of E histolytica to sexual partners or close contacts. © 2012 Elsevier Ltd.

Yu M.-C.,Taipei Medical University | Chen H.-Y.,Taipei Medical University | Wu M.-H.,Research and Diagnostic Center | Huang W.-L.,Research and Diagnostic Center | And 3 more authors.
Journal of Clinical Microbiology | Year: 2011

A culture confirmation test for the detection of Mycobacterium tuberculosis complex strains that uses a lateral-flow immunochromatographic assay to detect the MPB64 antigen, the MGIT TBc identification (TBc ID) test, has been developed. We evaluated the performance of the TBc ID test in the detection of the M. tuberculosis complex in 222 primary-positive liquid cultures. We compared these results to those of nucleic acid-based identification and conventional biochemical tests. The validity of the TBc ID test was determined, and all of the nontuberculous mycobacteria (NTM) and Nocardia species tested were found to be negative. The detection limit of the TBc ID test was 5 × 105 CFU/ml, and for IS6110 real-time PCR it was 5 CFU/ml. All of the M. tuberculosis and M. africanum cultures were found to be positive, while M. bovis and M. bovis BCG cultures were negative. With the exception of 1 contaminated culture, the 221 culture-positive isolates contained 171 (77.5%) M. tuberculosis isolates, 39 (17.6%) NTM species, and 11 (5.0%) unidentified species. Two culture-positive isolates harbored a 63-bp deletion at position 196 of the mpb64 gene. The sensitivity, specificity, positive predictive values, and negative predictive values of the TBc ID test were 98.8, 100, 100, and 95.1%, respectively. Furthermore, the approximate turnaround time for real-time PCR was 4 h (including buffer and sample preparation), while for the TBc ID test it was less than 1 h. We suggest an algorithm for the primary identification of M. tuberculosis in liquid culture using the TBc ID test as an alternative to conventional subculture followed by identification using biochemical methods. Copyright © 2011, American Society for Microbiology. All Rights Reserved.

Hsu B.-M.,National Chung Cheng University | Huang C.-C.,National Chung Cheng University | Chen J.-S.,National Chung Cheng University | Chen J.-S.,Research and Diagnostic Center | And 2 more authors.
Water Research | Year: 2011

This study compares five genera of free-living amoebae (FLA) hosts by Legionella spp. in the fixed and floating biofilm samples from spring environments. Detection rate of Legionella spp. was 26.9% for the floating biofilms and 3.1% for the fixed biofilms. Acanthamoeba spp., Hartmanella vermiformis, and Naegleria spp. were more frequently detected in floating biofilm than in fixed biofilm samples. The percentage of pathogenic Acanthamoeba spp. among all the genus Acanthamoeba detected positive samples was 19.6%. The potential pathogenic Naegleria spp. (for example, Naegleria australiensis, Naegleria philippinensis, and Naegleria italica) was 54.2% to all the Naegleria detected positive samples. In the study, 12 serotypes of possible pneumonia causing Legionella spp. were detected, and their percentage in all the Legionella containing samples was 42.4%. The FLA parasitized by Legionella included unnamed Acanthamoeba genotype, Acanthamoeba griffini, Acanthamoeba jacobsi, H. vermiformis, and N. australiensis. Significant differences were also observed between the presence/absence of H. vermiformis and Legionella parasitism in FLA. Comparisons between the culture-confirmed method and the PCR-based detection method for detecting FLA and Legionella in biofilms showed great variation. Therefore, using these analysis methods together to detect FLA and Legionella is recommended. © 2011 Elsevier Ltd.

Chuang P.-C.,Research and Diagnostic Center | Chen H.-Y.,Research and Diagnostic Center | Jou R.,Research and Diagnostic Center
Journal of Clinical Microbiology | Year: 2010

Mycobacterium tuberculosis isolates with a region of difference 105 (RD105) deletion, mainly Beijing family spoligotypes, were phylogenetically grouped into the East Asia lineage. We identified a single nucleotide polymorphism in codon 507, ATC to ATT, of the fadD28 gene as a robust marker and developed a rapid assay for East Asia lineage M. tuberculosis. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Wang S.-J.,Research and Diagnostic Center | Chiu S.-H.,Research and Diagnostic Center | Lin Y.-C.,Research and Diagnostic Center | Tsai Y.-C.,Research and Diagnostic Center | Mu J.-J.,Research and Diagnostic Center
Diagnostic Microbiology and Infectious Disease | Year: 2013

The spread of New Delhi metallo-β-lactamase gene (NDM-1)-producing bacteria has become a growing concern to the medical community worldwide. In this study, we reported 4 NDM-1-positive Enterobacteriaceae isolates recovered from two Taiwanese patients having travel history. The β-lactamase genetic background, antimicrobial susceptibility, clonal relationships, and plasmid sizes of the NDM-1-producing Enterobacteriaceae were investigated. This report highlights the alarming introduction of NDM-1 gene among Enterobacteriaceae in Taiwan. © 2013 Elsevier Inc.

Chang C.-W.,Research and Diagnostic Center | Wu M.-H.,Research and Diagnostic Center | Chuang P.-C.,Research and Diagnostic Center | Jou R.,Research and Diagnostic Center
Infection, Genetics and Evolution | Year: 2011

A population-based study was performed to characterize the genotype and drug-resistant patterns of multidrug-resistant tuberculosis (MDR-TB) in Taiwan. From 2007 to 2008, we analyzed 494 MDR Mycobacterium tuberculosis complex isolates using spacer oligonucleotide typing and drug susceptibility testing. The majority of cases occurred in the age groups of 45-54 (24.3%) and ≥65 (23.1%). Of the 494 MDR isolates, 25.1% were resistant to ethambutol, 15.6% were resistant to streptomycin, 27.1% were resistant to all four first-line anti-tuberculosis drugs, 28.9% were resistant to ofloxacin, and 8.7% were extensively drug-resistant (XDR). Compared with the SpolDB4, 86 spoligotypes were identified in 492 isolates. We observed 427 (86.8%) isolates belonging to 49 known spoligotypes and 65 isolates (13.2%) in 37 undesignated spoligotypes. Beijing lineages (50.0%) were the predominant genotype, followed by Haarlem (18.2%) and East-African-Indian (EAI) (5.7%). Geographically, Beijing lineages were predominant in all regions, whereas Haarlem lineages were predominant only in the east (28.1%) and EAI (11.3%) only in the south. Beijing lineages are statistically associated with MDR in younger age groups and eastern Taiwan. Furthermore, we found that Beijing ST1 (46.1%), Haarlem3 ST50 (7.1%) and ST742 (4.7%), and EAI2_MANILA ST19 (3.9%) were the prevalent groups. Thus, continuous surveillance with more thorough genotyping and epidemiological investigation is crucial for the prevention of further dissemination, the determination of the temporal and spatial trends of multi-drug resistance, and the emergence of XDR-TB in Taiwan. © 2011 Elsevier B.V.

Huang C.-T.,Research and Diagnostic Center | Li S.-Y.,Research and Diagnostic Center
Methods in Molecular Biology | Year: 2012

The identification of Chlamydia trachomatis genotypes is important for both molecular epidemiology and infection control such as contact tracing and identification of high-risk groups. Currently, at least 19 human serovars have been recognized by using polyclonal and monoclonal antibodies against the major outer membrane protein. In sexually transmitted diseases, multiple pathogens or genotype infections are not uncommon. Hence, detection of multiple gene targets in one reaction is becoming increasingly important. Here, we describe the multiplex detection of eight genotypes of C. trachomatis by a combination of a PCR amplification with a multiplex bead array detection. The bead array system comprises distinct bead sets, which are color coded by different fluorescent intensities and a dual-laser flow cytometer analyzer to identify the identity of the bead and the intensity of the reporter dye that binds to the target molecules. The DNA sequences of the variable segments (VS2 or VS1-VS2) in outer membrane protein (omp1) gene are PCR amplified and biotin labeled and used as a gene target for the genotyping of C. trachomatis. Genotype-specific probes coupled to beads are used for capturing the labeled target amplicons through specific hybridization. Thus, multiple genotypes are detected and differentiated simultaneously by yielding quantitative data. © 2012 Springer Science+Business Media New York.

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