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1.  Association of Fluoroquinolone Resistance, Virulence Genes, and IncF Plasmids with Extended-Spectrum-β-Lactamase-Producing Escherichia coli Sequence Type 131 (ST131) and ST405 Clonal Groups 
Antimicrobial Agents and Chemotherapy  2013;57(10):4736-4742.
The global increase of extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli is associated with the specific clonal group sequence type 131 (ST131). In order to understand the successful spread of ESBL-producing E. coli clonal groups, we characterized fluoroquinolone resistance determinants, virulence genotypes, and plasmid replicons of ST131 and another global clonal group, ST405. We investigated 41 ST131-O25b, 26 ST131-O16, 41 ST405, and 41 other ST (OST) ESBL-producing isolates, which were collected at seven acute care hospitals in Japan. The detection of ESBL types, fluoroquinolone resistance-associated mutations (including quinolone resistance-determining regions [QRDRs]), virulence genotypes, plasmid replicon types, and IncF replicon sequence types was performed using PCR and sequencing. blaCTX-M, specifically blaCTX-M-14, was the most common ESBL gene type among the four groups. Ciprofloxacin resistance was found in 90% of ST131-O25b, 19% of ST131-O16, 100% of ST405, and 54% of OST isolates. Multidrug resistance was more common in the ST405 group than in the ST131-O25 group (56% versus 32%; P = 0.045). All ST131-O25b isolates except one had four characteristic mutations in QRDRs, but most of the isolates from the other three groups had three mutations in common. The ST131-O25b and ST405 groups had larger numbers of virulence genes than the OST group. All of the ST131-O25b and ST405 isolates and most of the ST131-O16 and OST isolates carried IncF replicons. The most prevalent IncF replicon sequence types differed between the four clonal groups. Both the ST131-O25b and ST405 clonal groups had a fluoroquinolone resistance mechanism in QRDRs, multidrug resistance, high virulence, and IncF plasmids, suggesting the potential for further global expansion and a need for measures against these clonal groups.
doi:10.1128/AAC.00641-13
PMCID: PMC3811414  PMID: 23856781
2.  Clinical characteristics and risk factors of non-Candida fungaemia 
BMC Infectious Diseases  2013;13:247.
Background
The incidence of fungaemia has been increasing worldwide. It is important to distinguish non-Candida fungaemia from candidaemia because of their different antifungal susceptibilities. The aims of this study were to investigate the clinical characteristics of non-Candida fungaemia and identify the clinical factors that differentiate it from candidaemia.
Methods
We investigated the clinical manifestations and mortality of non-Candida fungaemia in Kyoto University Hospital from 2004 to 2009.
Results
There were 110 episodes of fungaemia during the study period. There were 11 renal replacement therapy episodes of fungaemia due to non-Candida yeasts (10.0%), including 6 episodes with Cryptococcus neoformans, 4 with Trichosporon asahii, and 1 with Kodamaea ohmeri, in addition to 99 episodes of candidaemia (90.0%). The presence of collagen disease [odds ratio (OR) 9.00; 95% confidence interval (CI) 1.58-51.4; P = 0.01] or renal replacement therapy (OR 15.0; 95% CI 3.06-73.4; P < 0.01) was significantly more common in non-Candida fungaemia patients than in candidaemia patients. Prior colonisation by the species may be a predictor of non-Candida fungaemia. Non-Candida fungaemia had a higher mortality than candidaemia (54.5% versus 21.2%, P = 0.03).
Conclusions
Although Candida species frequently cause fungaemia, we should also be aware of non-Candida yeasts because of their high mortality, particularly among high-risk patients, such as those with collagen disease and those under renal replacement therapy. Prior colonisation by the causative organisms may be an important predictor of non-Candida fungaemia.
doi:10.1186/1471-2334-13-247
PMCID: PMC3668224  PMID: 23714136
Fungaemia; Non-Candida yeast; Risk factor; Mortality; Colonisation
3.  Antimicrobial Ointments and Methicillin-Resistant Staphylococcus aureus USA300 
Emerging Infectious Diseases  2011;17(10):1917-1920.
We tested 259 methicillin-resistant Staphylococcus aureus isolates and 2 USA300 ATCC type strains for susceptibility to bacitracin and neomycin contained in over-the-counter antibacterial ointments. Resistance to both bacitracin and neomycin was found only in USA300. The use of over-the counter antimicrobial drugs may select for the USA300 clone.
doi:10.3201/eid1710.101365
PMCID: PMC3310646  PMID: 22000371
bacteria; antimicrobial drug resistant; methicillin-resistant Staphylococcus aureus; MRSA; over-the-counter; community acquired infections; nonprescription drugs; ointments; bacitracin; neomycin; polymyxin B; drug resistance; USA300; dispatch
4.  Clinical characteristics of Pneumocystis pneumonia in non-HIV patients and prognostic factors including microbiological genotypes 
Background
The number of patients with non-HIV Pneumocystis pneumonia (PCP) is increasing with widespread immunosuppressive treatment. We investigated the clinical characteristics of non-HIV PCP and its association with microbiological genotypes.
Methods
Between January 2005 and March 2010, all patients in 2 university hospitals who had been diagnosed with PCP by PCR were enrolled in this study. Retrospective chart review of patients, microbiological genotypes, and association with 30-day mortality were examined.
Results
Of the 82 adult patients investigated, 50 patients (61%) had inflammatory diseases, 17 (21%) had solid malignancies, 12 (15%) had hematological malignancies, and 6 (7%) had received transplantations. All patients received immunosuppressive agents or antitumor chemotherapeutic drugs. Plasma (1→3) β-D-glucan levels were elevated in 80% of patients, and were significantly reduced after treatment in both survivors and non-survivors. However, β-D-glucan increased in 18% of survivors and was normal in only 33% after treatment. Concomitant invasive pulmonary aspergillosis was detected in 5 patients. Fifty-six respiratory samples were stored for genotyping. A dihydropteroate synthase mutation associated with trimethoprim-sulfamethoxazole resistance was found in only 1 of the 53 patients. The most prevalent genotype of mitochondrial large-subunit rRNA was genotype 1, followed by genotype 4. The most prevalent genotype of internal transcribed spacers of the nuclear rRNA operon was Eb, followed by Eg and Bi. Thirty-day mortality was 24%, in which logistic regression analysis revealed association with serum albumin and mechanical ventilation, but no association with genotypes.
Conclusions
In non-HIV PCP, poorer general and respiratory conditions at diagnosis were independent predictors of mortality. β-D-glucan may not be useful for monitoring the response to treatment, and genotypes were not associated with mortality.
doi:10.1186/1471-2334-11-76
PMCID: PMC3073915  PMID: 21439061
5.  Necrotizing Fasciitis Caused by Haemophilus influenzae Type b in an Elderly Patient▿  
Journal of Clinical Microbiology  2008;47(3):852-854.
Necrotizing fasciitis caused by Haemophilus influenzae type b is a rare infection of the skin and soft tissues. The only previously reported case involved a healthy infant. We report herein the case of an 81-year-old Japanese woman with diabetes mellitus who developed necrotizing fasciitis caused by H. influenzae type b.
doi:10.1128/JCM.01196-08
PMCID: PMC2650905  PMID: 19116357
6.  Variations in amount of TSST-1 produced by clinical methicillin resistant Staphylococcus aureus (MRSA) isolates and allelic variation in accessory gene regulator (agr) locus 
BMC Microbiology  2009;9:52.
Background
Staphylococcus aureus (S. aureus) is an important pathogen associated with both nosocomial and community-acquired infections and its pathogenicity is attributed to its potential to produce virulence factors. Since the amount of toxin produced is related to virulence, evaluating toxin production should be useful for controlling S. aureus infection. We previously found that some strains produce relatively large amounts of TSST-1; however, no reports have described the amount of TSST-1 produced by clinical isolates.
Methods
Amounts of TSST-1 produced by clinical methicillin resistant S. aureus (MRSA) isolates were measured by Western blotting. We determined their accessory gene regulator (agr) class by PCR and investigated whether TSST-1 production correlates with variations in the class and structure of the agr.
Results
We found that 75% of surveyed MRSA isolates (n = 152) possessed the tst gene and that 96.7% belonged to agr class 2. The concentrations of TSST-1 secreted into culture supernatants by 34 strains measured by Western blotting differed 170-fold. Sequencing the entire agr locus (n = 9) revealed that some had allelic variations regardless of the amount of TSST-1 produced whereas sequencing the sar, sigma factor B and the tst promoter region revealed no significant changes.
Conclusion
The amounts of TSST-1 produced by clinical MRSA isolates varied. The present results suggest that TSST-1 production is not directly associated with the agr structure, but is instead controlled by unknown transcriptional/translational regulatory systems, or synthesized by multiple regulatory mechanisms that are interlinked in a complex manner.
doi:10.1186/1471-2180-9-52
PMCID: PMC2667389  PMID: 19272162

Results 1-6 (6)