8 results on '"Yosuke Aoki"'
Search Results
2. Distribution of Legionella species and serogroups in patients with culture-confirmed Legionella pneumonia
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Toshiaki Kikuchi, Masafumi Seki, Hiroshi Kiyota, Naoyuki Miyashita, Yosuke Aoki, Futoshi Higa, Kazuhiro Uchino, Nobuko Maki, Kazuhiko Ogasawara, Kazuhiro Tateda, and Akira Watanabe
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0301 basic medicine ,Microbiology (medical) ,Male ,medicine.drug_class ,Legionella ,030106 microbiology ,Antibiotics ,Legionella Pneumonia ,Microbial Sensitivity Tests ,Serogroup ,Legionella pneumophila ,Microbiology ,03 medical and health sciences ,0302 clinical medicine ,Community-acquired pneumonia ,Japan ,medicine ,Pneumonia, Bacterial ,Humans ,Pharmacology (medical) ,In patient ,030212 general & internal medicine ,Serotyping ,Aged ,Legionellosis ,biology ,business.industry ,Middle Aged ,bacterial infections and mycoses ,medicine.disease ,biology.organism_classification ,respiratory tract diseases ,Anti-Bacterial Agents ,Community-Acquired Infections ,Pneumonia ,Infectious Diseases ,bacteria ,Female ,Legionella species ,Legionnaires' Disease ,business - Abstract
Legionella species are consistently identified as some of the most common causative agents of severe community-acquired pneumonia (CAP) or nosocomial pneumonia. Although the number of reported Legionella infection cases is gradually increasing in Japan, most cases are diagnosed by a urinary antigen test, which identifies only L. pneumophila serogroup 1. Therefore, assessment of pneumonia-causing Legionella species and serogroups would be important. The Japan Society for Chemotherapy Legionella committee has collected the isolates and clinical information on cases of sporadic community-acquired Legionella pneumonia throughout Japan. Between December 2006 and March 2019, totally 140 sporadic cases were identified, in which L. pneumophila was the most frequently isolated species (90.7%) followed by L. bozemanae (3.6%), L. dumofii (3.6%), L. micdadei (1.4%), and L. longbeachae (0.7%). Among 127 isolates of L. pneumophila, 111 isolates were of serogroup 1, two of serogroup 2, four of serogroup 3, one of serogroup 4, one of serogroup 5, seven of serogroup 6, and one was of serogroup 10. We also assessed in vitro activity of antibiotics against these isolates and showed that quinolones and macrolides have potent anti-Legionella activity. Our study showed that pneumonia-causing Legionella species and serogroup distribution was comparable to that reported in former surveillances. L. pneumophila was the most common etiologic agent in patients with community-acquired Legionella pneumonia, and L. pneumophila serogroup 1 was the predominant serogroup.
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- 2019
3. The first nationwide survey of antimicrobial stewardship programs conducted by the Japanese Society of Chemotherapy
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Tatsuya Kawaguchi, Katsunori Yanagihara, Mitsuo Kaku, Yoshinari Tanabe, Koichiro Yoshida, Masayuki Maeda, Tadashi Kosaka, Naohisa Fujita, Yuichi Muraki, Masafumi Seki, Takehiro Yamada, Yosuke Aoki, Yoshihito Niki, and Kunihiko Morita
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Microbiology (medical) ,medicine.medical_specialty ,business.industry ,Nationwide survey ,Antimicrobial Stewardship ,Infectious Diseases ,Drug Therapy ,Japan ,Family medicine ,Surveys and Questionnaires ,medicine ,Antimicrobial stewardship ,Humans ,Pharmacology (medical) ,Full-time equivalent ,Human resources ,business ,Societies, Medical - Published
- 2018
4. Clinical utility of direct application of matrix-assisted laser desorption ionization time-of-flight mass spectrometry and rapid disk diffusion test in presumptive antimicrobial therapy for bacteremia
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Hiroki Magarifuchi, Yosuke Aoki, Toshiharu Urakami, Yohei Hamada, Megumi Oho, and Koji Kusaba
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0301 basic medicine ,Microbiology (medical) ,Male ,medicine.medical_specialty ,Time Factors ,medicine.drug_class ,030106 microbiology ,Antibiotics ,Matrix assisted laser desorption ionization time of flight ,Bacteremia ,Bacterial Physiological Phenomena ,Teaching hospital ,03 medical and health sciences ,0302 clinical medicine ,Carbapenem Antibiotics ,Disk Diffusion Antimicrobial Tests ,Internal medicine ,medicine ,Humans ,Pharmacology (medical) ,030212 general & internal medicine ,Aged ,Bacteria ,business.industry ,Middle Aged ,Antimicrobial ,medicine.disease ,Anti-Bacterial Agents ,Clinical Practice ,Infectious Diseases ,Treatment Outcome ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Female ,Historical control ,business - Abstract
Objective To study how and to what degree the rapid pathogen identification by MALDI-TOF MS coupled with rapid disk diffusion test improve the current clinical practice of patients with bacteremia in a tertiary teaching hospital with full-time ID consultation service. Patients and methods MALDI-TOF MS and 8H disk diffusion tests were directly applied to the positive blood cultures samples and the results were reflected on antimicrobial therapy (n = 119). The appropriateness of antimicrobial selection through these interventions was verified with conventional culture results in comparison with historical control (n = 129). The mortality of patients between the two periods was also compared. Results The appropriateness of antimicrobial selection was higher (99.2%) in the intervention than in the control group (93.8%) (p 0.024), but there was no difference in 28-day mortality between the two periods (16.8%, 14.8%) (p 0.668). The duration of presumptive antimicrobial therapy with anti-MRSA agents and carbapenem antibiotics did not differ between the two periods indicating that the intervention was not effective in decreasing the unnecessary antibiotics. On the other hand, some bacteremic patients with pathogens whose drug susceptibilities were invariably sensitive to the standard class of antibiotics definitely benefitted from the intervention. Conclusion The intervention utilizing MALDI-TOF MS and the rapid disk diffusion test may not demonstrate overall improvement in bacteremia mortality in the institution with full-time infectious disease consultants. Its utility has yet to be evaluated in different setting hospitals.
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- 2018
5. In vitro activity of various antibiotics against clinical strains of Legionella species isolated in Japan
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Tatsuya Ishikawa, Hiroshi Kiyota, Nobuko Maki, Satoe Kurachi, Akira Watanabe, Intetsu Kobayashi, Izumo Kanesaka, Masafumi Seki, Yosuke Aoki, Naoyuki Miyashita, Kazuhiko Ogasawara, Kazuhiro Uchino, Toshiaki Kikuchi, Futoshi Higa, Yoshito Ishimura, and Kazuhiro Tateda
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0301 basic medicine ,Microbiology (medical) ,medicine.drug_class ,THP-1 Cells ,030106 microbiology ,Antibiotics ,Microbial Sensitivity Tests ,Quinolones ,Serogroup ,Garenoxacin ,Microbiology ,Legionella pneumophila ,03 medical and health sciences ,chemistry.chemical_compound ,Minimum inhibitory concentration ,0302 clinical medicine ,Japan ,Moxifloxacin ,Levofloxacin ,Legionella longbeachae ,Pazufloxacin ,medicine ,Humans ,Pharmacology (medical) ,030212 general & internal medicine ,Chemistry ,biochemical phenomena, metabolism, and nutrition ,bacterial infections and mycoses ,Anti-Bacterial Agents ,Ciprofloxacin ,Infectious Diseases ,bacteria ,Macrolides ,Rifampicin ,medicine.drug - Abstract
The activities of various antibiotics against 58 clinical isolates of Legionella species were evaluated using two methods, extracellular activity (minimum inhibitory concentration [MIC]) and intracellular activity. Susceptibility testing was performed using BSYEα agar. The minimum extracellular concentration inhibiting intracellular multiplication (MIEC) was determined using a human monocyte-derived cell line, THP-1. The most potent drugs in terms of MICs against clinical isolates were levofloxacin, garenoxacin, and rifampicin with MIC90 values of 0.015 μg/ml. The activities of ciprofloxacin, pazufloxacin, moxifloxacin, clarithromycin, and azithromycin were slightly higher than those of levofloxacin, garenoxacin, and rifampicin with an MIC90 of 0.03–0.06 μg/ml. Minocycline showed the highest activity, with an MIC90 of 1 μg/ml. No resistance against the antibiotics tested was detected. No difference was detected in the MIC distributions of the antibiotics tested between L. pneumophila serogroup 1 and L. pneumophila non-serogroup 1. The MIECs of ciprofloxacin, pazufloxacin, levofloxacin, moxifloxacin, garenoxacin, clarithromycin, and azithromycin were almost the same as their MICs, with MIEC90 values of 0.015–0.06 μg/ml, although the MIEC of minocycline was relatively lower and that of rifampicin was higher than their respective MICs. No difference was detected in the MIEC distributions of the antibiotics tested between L. pneumophila serogroup 1 and L. pneumophila non-serogroup 1. The ratios of MIEC:MIC for rifampicin (8) and pazufloxacin (2) were higher than those for levofloxacin (1), ciprofloxacin (1), moxifloxacin (1), garenoxacin (1), clarithromycin (1), and azithromycin (1). Our study showed that quinolones and macrolides had potent antimicrobial activity against both extracellular and intracellular Legionella species. The present data suggested the possible efficacy of these drugs in treatment of Legionella infections.
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- 2017
6. Enterococcal endocarditis complicated with ruptured infected-intracranial aneurysm: with pharmacokinetic-pharmacodynamic documentation in proof of the successful antimicrobial treatment
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Yohei Hamada, Hiroki Magarihuchi, Yosuke Aoki, Hiroki Yamakuchi, and Tosiharu Urakami
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Microbiology (medical) ,Male ,medicine.medical_specialty ,Enterococcus faecium ,Cefazolin ,Microbial Sensitivity Tests ,Aneurysm, Ruptured ,Gastroenterology ,Minimum inhibitory concentration ,Internal medicine ,Ampicillin ,medicine ,Endocarditis ,Humans ,Pharmacology (medical) ,Blood culture ,Gram-Positive Bacterial Infections ,Aged ,Minimum bactericidal concentration ,medicine.diagnostic_test ,business.industry ,Brain ,Intracranial Aneurysm ,Endocarditis, Bacterial ,medicine.disease ,Magnetic Resonance Imaging ,Surgery ,Anti-Bacterial Agents ,Infectious Diseases ,Treatment Outcome ,Infective endocarditis ,business ,Piperacillin ,medicine.drug - Abstract
A 74-year-old man presented with sudden onset of aphasia and apraxia. Magnetic resonance image (MRI) of the brain disclosed a left frontal hemorrhage. The concomitant low grade fever suggestive of infection was unresponsive to cefazolin 1 g q12h, and refractory to piperacillin (PIPC) 2 g q8h. Blood culture grew enterococci, establishing together with echocardiography the diagnosis of infective endocarditis. The angiography revealed cerebral hemorrhage to have resulted from the rupture of the infected intracranial aneurysm. The antimicrobial therapy was switched to ampicillin (ABPC) 2 g q4h plus gentamicin (GM) 60 mg q8h. The positive blood culture was subsequently identified Enterococcus faecium to which the minimum inhibitory concentration (MIC) of PIPC, and ABPC was 16 mcg/mL, and 4 mcg/mL, respectively. The peak concentration of serum ABPC was 83.1, median 50.8, and trough 25.8 mcg/mL. Thus, the percent time > MIC for ABPC was 100%, and the time > minimum bactericidal concentration (MBC) as well. On the other hand, time > MIC for PIPC, was found nearly 30% in retrospective analysis using population pharmacokinetics. The neurological deficit of the patient was completely restored to the normal status after 4-weeks' antimicrobial therapy with ABPC plus GM, then he underwent cardiac surgery for valvular replacement, where microbiological culture of the resected valve was negative. The constellation of the clinical, pharmacological and microbiological outcome in our case provides scientific evidence that the antibiotic therapy given to our case is the best available strategy as an antimicrobial treatment of severe enterococcal endocarditis complicated by disseminated lesion as infected intracranial aneurysm.
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- 2014
7. Antibiotic susceptibility survey of blood-borne MRSA isolates in Japan from 2008 through 2011
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Shigeki Fujitani, Junichi Honda, Taiji Nakae, Yoshihito Niki, Katsunori Yanagihara, Yoshio Takesue, Yoshio Yamaguchi, Keisuke Sunakawa, Kazuhiro Tateda, Kazunori Tomono, Mitsuo Kaku, Yoshihito Otsuka, Longzhu Cui, Shinya Kusachi, Kunihiko Fukuchi, Hideaki Hanaki, Osanori Nagura, Tohru Takata, Yurika Ikeda-Dantsuji, Shigeru Kohno, Tetsuya Matsumoto, Hiroshige Mikamo, Yosuke Aoki, and Jun-ichi Kadota
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Microbiology (medical) ,Methicillin-Resistant Staphylococcus aureus ,Imipenem ,Microbial Sensitivity Tests ,medicine.disease_cause ,beta-Lactams ,Meropenem ,Microbiology ,chemistry.chemical_compound ,Japan ,medicine ,Humans ,Pharmacology (medical) ,Arbekacin ,Teicoplanin ,business.industry ,Clindamycin ,Vancomycin Resistance ,biochemical phenomena, metabolism, and nutrition ,Staphylococcal Infections ,bacterial infections and mycoses ,Methicillin-resistant Staphylococcus aureus ,Anti-Bacterial Agents ,Infectious Diseases ,chemistry ,Linezolid ,Vancomycin ,business ,medicine.drug - Abstract
We conducted an antibiotic susceptibility survey of 830 blood-borne methicillin resistant Staphylococcus aureus collected from nationwide hospitals in Japan over a three-year period from January 2008 through May 2011. Antibiotic susceptibility was judged according to the criteria recommended by the Clinical Laboratory Standard Institute. Over 99% of the MRSA showed to be susceptible to teicoplanin, linezolid, sulfamethoxazole/trimethoprim and vancomycin, and over 97% of them were susceptible to daptomycin, arbekacin and rifampin. The majority of the MRSA strains showed resistant to minocycline, meropenem, imipenem, clindamycin, ciprofloxacin, cefoxitin, and oxacillin in the rates of 56.6, 72.9, 73.7, 78.7, 89.0, 99.5, and 99.9%, respectively. Among the MRSA strains, 72 showed reduced susceptibility to vancomycin, including 8 strains (0.96%) of vancomycin-intermediate S. aureus (VISA), 54 (6.51%) of heterogeneous vancomycin-intermediate S. aureus (hVISA), and 55 (5.63%) of β-lactam antibiotics-induced vancomycin resistant S. aureus (BIVR). Unexpectedly, among the 54 hVISA and 55 BIVR, 45 isolates (83.3% and 81.8%, respectively) showed both hVISA and BIVR phenotypes. A new trend of vancomycin resistance found in this study was that VISA strains were still prevalent among the bacteremic specimens. The high rates of the hVISA/BIVR two-phenotypic vancomycin resistance, and the prevalence of VISA in the bloodborne MRSA call attention in the MRSA epidemiology in Japan.
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- 2013
8. Susceptibility of clinical isolates of Pseudomonas aeruginosa in the Northern Kyushu district of Japan to carbapenem antibiotics, determined by an integrated concentration method: evaluation of the method based on Monte Carlo simulation
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Yosuke Aoki, Koji Kusaba, and Zenzo Nagasawa
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Microbiology (medical) ,Adult ,Veterinary medicine ,Imipenem ,Carbapenem ,Microbial Sensitivity Tests ,Pharmacology ,Biology ,medicine.disease_cause ,Meropenem ,Japan ,medicine ,Humans ,Pharmacology (medical) ,Pseudomonas Infections ,Biapenem ,Infusions, Intravenous ,Pseudomonas aeruginosa ,Panipenem ,Infectious Diseases ,Carbapenems ,Pharmacodynamics ,Doripenem ,Monte Carlo Method ,medicine.drug - Abstract
In empirical antibacterial therapy, regional surveillance is expected to yield important information for the determination of the class and dosage regimen of antibacterial agents to be used when dealing with infections with organisms such as Pseudomonas aeruginosa, in which strains resistant to antibacterial agents have been increasing. The minimal inhibitory concentrations (MICs) of five carbapenem antibiotics against P. aeruginosa strains isolated in the Northern Kyushu district of Japan between 2005 and 2006 were measured, and 100 strains for which carbapenem MICs wereor =0.5-32 microg/ml were selected. In this study, MIC was measured by two methods, i.e., the common serial twofold dilution method and an integrated concentration method, in which the concentration was changed, in increments of 2 microg/ml, from 2 to 16 microg/ml. The MIC(50)/MIC(90) values for imipenem, meropenem, biapenem, doripenem, and panipenem, respectively, with the former method were 8/16, 4/16, 4/16, 2/8, and 16/16 microg/ml; and the values were 6/10, 4/12, 4/10, 2/6, and 10/16 microg/ml with the latter method. The MIC data obtained with both methods were subjected to pharmacokinetic/pharmacodynamic (PK/PD) analysis with Monte Carlo simulation to calculate the probability of achieving the target of time above MIC (TMIC) with each carbapenem. The probability of achieving 25% time above the MIC (TMIC; % of TMIC for dosing intervals) and 40% TMIC against P. aeruginosa with any dosage regimen was higher with doripenem than with any other carbapenem tested. When the two sets of MIC data were subjected to PK/PD analysis, the difference between the two methods in the probability of achieving each % TMIC was small, thus endorsing the validity of the serial twofold dilution method.
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- 2007
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