Publications (76) View all
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Article: Multidrug-resistant Salmonella enterica serovar Panama carrying class 1 integrons is invasive in Taiwanese children.
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ABSTRACT: An increase in group D Salmonella isolates with high antimicrobial resistant rates is being seen in Taiwan. This study aimed to determine the multidrug-resistant (MDR, more than three antibiotics) phenotype, genotype, and the correlation between the presence of class 1 integrons and its invasiveness of Salmonella panama and Salmonella enteritidis isolated from children. Twenty S. panama and 59 S. enteritidis isolates were examined for minimal inhibitory concentrations of ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline by agar dilution method. The presence of blaPSE-1, floR, aadA2, sul1, and tet(G) resistance genes, class 1 integrons, and Salmonella genomic island 1 (SGI1) was identified by polymerase chain reaction. The adhesion and invasion assays of S. panama to Caco-2 cells were determined using the pour plate method. All S. panama and 15 (25.4%) of the S. enteritidis isolates displayed MDR phenotype. Furthermore, MDR genotype was present in 70.0% of S. panama and 6.8% of S. enteritidis. Class 1 integrons were present in 40.0% of S. panama and 11.9% of S. enteritidis. None contained SGI1 or SGI1 variants. Strains carrying class 1 integrons were more frequently isolated from bacteria with MDR (73.3% vs. 37.5%; odds ratio, 4.6; 95% confidence interval, 1.3-16.0; p=0.01) and isolated from blood and cerebrospinal fluid (46.7% vs. 21.9%; odds ratio, 3.1; 95% confidence interval, 1.0-10.1; p=0.05) than noncarriers. S. panama carrying class 1 integrons were more invasive to Caco-2 cells than those without (p=0.01). S. panama and S. enteritidis with class 1 integrons are significantly related to the presence of MDR phenotype. Moreover, S. panama with class 1 integrons may present more invasiveness than those without.Journal of the Formosan Medical Association 05/2013; 112(5):269-75. · 1.13 Impact Factor -
Article: A Reduction in Anti-Tuberculosis Drug Resistance after the Implementation of the National "STOP TB" Program in Central Taiwan, 2003-2007.
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ABSTRACT: The aim of this study was to determine the performance of the national "STOP TB" program in central Taiwan during 2003-2007 by examining trends in the combined drug resistance to first-line anti-tuberculosis (TB) drugs among clinical Mycobacterium tuberculosis isolates. Using 4,819 clinical M. tuberculosis isolates obtained from two mycobacteriology referral laboratories, the resistance to drugs was measured and analyzed along with the treatment outcomes in notified TB patients. The proportion of isolates showing total resistance and multidrug-resistant tuberculosis (MDR-TB) isolates were 17.7% and 3.67%, respectively. More number of MDR-TB isolates showed high-level resistance to isoniazid (84.18%) and streptomycin (SM) (30.51%); low-level resistance to ethambutol (EMB) (61.58%), SM (41.81%), and pyrazinamide (66.1%); and resistance to ofloxacin (30.4%). However, fewer isolates showed high-level resistance to EMB (19.77%), levofloxacin (17.9%), moxifloxacin (19.6%), kanamycin (8.9%), amikacin (8.9%), and capreomycin (8.9%). Of these MDR-TB isolates, 7.1% were extensively drug-resistant. Trends in combined drug resistance to all the first-line anti-TB drugs and the incidence of MDR-TB were stable during the 2 years (2003-2004) before the implementation of the national "STOP TB" program. After the "STOP TB" program, there were significant declines in the incidence of MDR-TB during 2005-2007 in central Taiwan as well as improved TB-treatment outcomes. Thus, the national "STOP TB" program had a significant positive impact on TB control in central Taiwan.Japanese journal of infectious diseases. 01/2013; 66(2):89-95. -
Article: Salmonella enterica serovar Typhi variants in long-term carriers.
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ABSTRACT: Long-term typhoid carriers can simultaneously excreted Salmonella enterica serovar Typhi variants with considerable genetic differences, a situation that complicates the interpretation of the subtyping data used in outbreak investigations and disease surveillance.Journal of clinical microbiology 12/2012; · 4.16 Impact Factor -
Article: Human isolates of Salmonella enterica serovar Typhimurium from Taiwan displayed significantly higher levels of antimicrobial resistance than those from Denmark.
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ABSTRACT: Salmonella enterica serovar Typhimurium is a major zoonotic pathogen with a high prevalence of antimicrobial resistance. This pathogen can disseminate across borders and spread far distances via the food trade and international travel. In this study, we compared the genotypes and antimicrobial resistance of 378 S. Typhimurium isolates collected in Taiwan and Denmark between 2009 and 2010. Genotyping revealed that many S. Typhimurium strains were concurrently circulating in Taiwan, Denmark and other countries in 2009 and 2010. When compared to the isolates collected from Denmark, the isolates from Taiwan displayed a significantly higher level of resistance to 11 of the 12 tested antimicrobials. Seven genetic clusters (A-G) were designated for the isolates. A high percentage of the isolates in genetic clusters C, F and G were multidrug-resistant. Of the isolates in cluster C, 79.2% were ASSuT-resistant, characterized by resistance to ampicillin, streptomycin, sulfamethoxazole, and tetracycline. In cluster F, 84.1% of the isolates were ACSSuT-resistant (resistant to ASSuT and chloramphenicol). Cluster G was unique to Taiwan and characterized in most isolates by the absence of three VNTRs (ST20, ST30 and STTR6) as well as a variety of multidrug resistance profiles. This cluster exhibited very high to extremely high levels of resistance to several first-line drugs, and among the seven clusters, it displayed the highest levels of resistance to cefotaxime and ceftazidime, ciprofloxacin and gentamicin. The high prevalence of antimicrobial resistance in S. Typhimurium from Taiwan highlights the necessity to strictly regulate the use of antimicrobials in the agriculture and human health care sectors.International journal of food microbiology 12/2012; 161(2):69-75. · 3.01 Impact Factor -
Article: Suitable restriction enzyme for standardization of pulsed-field gel electrophoresis protocol and interlaboratory comparison of Acinetobacter baumannii.
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ABSTRACT: BACKGROUND/PURPOSE: Interlaboratory comparison of pulsed-field gel electrophoresis (PFGE) patterns is difficult. A key reference of standardized PFGE protocol for Acinetobacter baumannii may address this issue. This study aimed to determine restriction enzymes with rare cutting sites on A baumannii genomes and evaluate their cost-effectiveness, discriminatory power, and interlaboratory consistence of band assignments. METHODS: There were 42 A baumannii isolates collected, including nine from three hospital outbreaks and 33 sporadic isolates. The numbers of cutting sites for the restriction enzymes were explored using the "Restriction Digest and PFGE" program. The cost-effectiveness for PFGE analysis was evaluated for the tested restriction enzymes, while its discriminatory ability was expressed through a discriminatory index and 95% confidence interval. The interlaboratory consistence of band assignments was evaluated for the 42 A baumannii isolates. RESULTS: ApaI was the most cost-effective restriction enzyme for a PFGE protocol for A baumannii. Both AscI and AsiSI were reasonable in terms of costs. ApaI, AscI, and AsiSI exhibited similar discriminatory indices. ApaI generated more than 40 fragments that were close and not easy to resolve, resulting in less consistence of band assignments. AscI and AsiSI generated 10-20 fragments that were clearly resolved, resulting in higher consistence of band assignments. AscI exhibited a close discriminatory power to that of AsiSI and at half of the cost of AsiSI for PFGE analysis. CONCLUSION: We recommend AscI as the primary enzyme and AsiSI as the secondary enzyme for standardizing the PFGE protocol and interlaboratory comparisons of A baumannii.Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi 07/2012; · 0.99 Impact Factor
