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Kim M.J.,Eulji University | Bae I.K.,Yonsei University | Jeong S.H.,Eulji University | Jeong S.H.,Yonsei University | And 10 more authors.
Journal of Antimicrobial Chemotherapy | Year: 2013

Objectives: To investigate the epidemiological traits of metallo-b-lactamase (MBL)-producing Pseudomonas aeruginosa (MPPA) clinical isolates collected by the Asian Network for Surveillance of Resistant Pathogens (ANSORP). Methods:Atotal of16MPPAclinical isolateswerecollected fromsix Asian countries in2000to2009byANSORP.The MBLgenewasdetected byPCRamplification. The genetic organization of the class1integroncarrying theMBLgene cassettewas investigated by PCR mapping and sequencing. Southern blotting, repetitive sequence-based PCR and multilocus sequence typing (MLST) experiments were performed to characterize the isolates. Results: PCR and sequencing experiments detected the blaVIM-2 (n=12), blaVIM-3 (n=1), blaIMP-6 (n=2) and blaIMP-26 (n=1) genes. The MBL genes were located on the chromosome in all isolates except one. Furthermore, all the MBL genes were located in a class 1 integron. All the MPPA isolates from Malaysia, Thailand, Sri Lanka and Korea were identified as sequence type (ST) 235 by MLST. Three VIM-2-producing isolates fromIndia were identified as ST773, and one isolate harbouring VIM-3 from Taiwan was identified as ST298. Conclusions: P. aeruginosa ST235might play a role in dissemination of MBL genes in Asian countries. © The Author 2013. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

Ha Y.E.,Sungkyunkwan University | Kang C.-I.,Sungkyunkwan University | Cha M.K.,Asia Pacific Foundation for Infectious Diseases APFID | Park S.Y.,Sungkyunkwan University | And 5 more authors.
International Journal of Antimicrobial Agents | Year: 2013

Patients with cancer can be vulnerable to infection with antimicrobial-resistant pathogens such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. A cohort study was performed to evaluate the epidemiology and impact of ESBL-producing Escherichia coli (ESBL-EC) bacteraemia on the outcomes of adult patients with cancer. During the 2.5-year study period, a total of 350 cases of E. Coli bacteraemia were documented in cancer patients, of which 95 (27.1%) were due to ESBL-EC. Significant factors associated with ESBL-EC bacteraemia were liver disease, immunosuppressant use, recent surgery, and prior use of cephalosporins or fluoroquinolones. The overall 30-day mortality rate was 14.9% (52/350), and the mortality rate was higher in patients with ESBL-EC than in those without ESBL-EC (22.1% vs.12.2%; P = 0.02). Multivariate analysis showed that ESBL-EC was an independent risk factor for mortality (odds ratio = 3.01, 95% confidence interval 1.45-6.28; P = 0.003), along with the presence of septic shock, mechanical ventilation, the severity of underlying diseases, and pneumonia as a source of bacteraemia. Of the 69 isolates in which ESBLs and their molecular relationships were studied, 68 (98.6%) produced CTX-M-type and 51 (73.9%) produced CTX-M-14 and/or CTX-M-15. Twenty-four sequence types (STs) were identified among CTX-M-14- and CTX-M-15-producing E. Coli isolates, with ST131 being the most prevalent (12/51; 23.5%). In conclusion, this study confirms that CTX-M-producing E. Coli and ST131, which have been shown to be an emerging public health threat, are widely prevalent in cancer patients and can adversely affect the outcome of E. Coli bacteraemia in these patients. © 2013 Elsevier B.V. and the International Society of Chemotherapy.

Kang C.-I.,Sungkyunkwan University | Song J.-H.,Sungkyunkwan University | Kim S.H.,Asia Pacific Foundation for Infectious Diseases APFID | Chung D.R.,Sungkyunkwan University | And 3 more authors.
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2014

This study was performed to evaluate the clinical features of community-onset levofloxacin-nonsusceptible pneumococcal pneumonia and to identify risk factors for levofloxacin resistance. Using the database of a surveillance study of community-acquired pneumococcal infections in Asian countries, we conducted a nested case-control study to identify risk factors for levofloxacin-nonsusceptible S. pneumoniae in community-acquired pneumonia in adults. Of 981 patients with pneumococcal pneumonia, 46 (4.7 %) had levofloxacin-nonsusceptible S. pneumoniae, of whom 39 evaluable cases were included in the analysis. All cases were from Korea, Taiwan, and Hong Kong. Among patients with levofloxacin-susceptible S. pneumoniae, 490 controls were selected based on patient country. Of the 39 cases of levofloxacin- nonsusceptible pneumococcal pneumonia, 23 (59.0 %) were classified as healthcare-associated, while 164 (33.5 %) of the 490 controls of levofloxacin-susceptible S. pneumoniae (P = 0.001) were classified as healthcare-associated. Multivariate analysis showed that previous treatment with fluoroquinolones, cerebrovascular disease, and healthcare-associated infection were significantly associated with levofloxacin-nonsusceptible pneumococcal pneumonia (all P < 0.05). Levofloxacin-nonsusceptible pneumococci pose an important new public health threat in our region, and more information on the emergence and spread of these resistant strains will be necessary to prevent spread throughout the population. © 2013 Springer-Verlag Berlin Heidelberg.

Ko K.S.,Sungkyunkwan University | Baek J.Y.,Asia Pacific Foundation for Infectious Diseases APFID | Song J.-H.,Asia Pacific Foundation for Infectious Diseases APFID | Song J.-H.,Sungkyunkwan University
Journal of Clinical Microbiology | Year: 2013

To characterize Streptococcus pneumoniae "serotype 6E," complete cps loci were sequenced. The capsular genes of "serotype 6E" isolates differed much from those of serotypes 6A and 6B. We identified 10 additional "serotype 6E" isolates, which are not confined to a restricted geographic locality. Most of these "serotype 6E" isolates belonged to sequence type 90 and its single-locus variants. The homogeneity of their genetic background and cps loci suggests a recent origin ofthe "serotype 6E" isolates. Copyright © 2013, American Society for Microbiology.

Baek J.-Y.,Asia Pacific Foundation for Infectious Diseases APFID | Park I.-H.,Ewha Womans University | Song J.-H.,Asia Pacific Foundation for Infectious Diseases APFID | Song J.-H.,Sungkyunkwan University | And 2 more authors.
Journal of Clinical Microbiology | Year: 2014

The prevalence of serogroup 6 among 1,206 Streptococcus pneumoniae clinical isolates collected from Korean hospitals over three periods (1996 to 2001, 2004 to 2006, and 2008 to 2009) was investigated. The number of serogroup 6 isolates increased from 9.7 to 17.5% over the three periods. While the proportion of serotype 6A and 6D isolates increased significantly, that of serotype 6B isolates decreased. Twenty-four isolates (2.0%) were typed as the recently identified putative serotype 6E or genetic variants of serotype 6B. The results suggest that the lack of change in frequency of serotype 6B, in spite of the introduction of the PCV7 vaccine as seen in previous studies in South Korea, might be due mainly to the improper inclusion of putative serotype 6E in serotype 6B. All but three serotype 6E isolates belonged to CC90, indicating their clonal expansion. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

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