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Kyoichi Totsuka

Publications and source records attributed to Kyoichi Totsuka.

At least 19 recordsLinked to original sources

Clinical features of 62 imported cases of dengue fever in Japan.

To describe the clinical features of dengue cases in Japan, a retrospective study was conducted on 62 laboratory-confirmed Japanese dengue cases presented to Tokyo Metropolitan Komagome Hospital between 1985 and 2000. Age distribution was from 18 to 62 years old (mean, 31.5 years). All cases were imported from abroad and diagnosed as dengue fever. Clinical manifestations included fever (100%), headache (90%), and skin rash (82%). Laboratory examinations revealed leukocytopenia (71%), thrombocytopenia (57%), elevated levels of serum aspartate aminotransferase (78%), and lactate dehydrogenase (71%). Antibody responses were consistent with that of secondary flavivirus infection in 60% of cases. Severity of symptoms in patients with primary dengue antibody response and those with secondary flavivirus antibody responses didn't show statistical significance. Dengue virus infection should be taken into consideration in the differential diagnosis of febrile patients who recently entered Japan from tropical or subtropical countries.

Adolescent↗

Multicenter prospective study of procalcitonin as an indicator of sepsis.

The clinical significance of serum procalcitonin (PCT) for discriminating between bacterial infectious disease and nonbacterial infectious disease (such as systemic inflammatory response syndrome (SIRS)), was compared with the significance of endotoxin, beta-D: -glucan, interleukin (IL)-6, and C-reactive protein (CRP) in a multicenter prospective study. The concentrations of PCT in patients with systemic bacterial infection and those with localized bacterial infection were significantly higher than the concentrations in patients with nonbacterial infection or noninfectious diseases. In addition, PCT, endotoxin, IL-6, and CRP concentrations were significantly higher in patients with bacterial infectious disease than in those with nonbacterial infectious disease (P<0.001, P<0.005, P<0.001, and P<0.001, respectively). The cutoff value of PCT for the discrimination of bacterial and nonbacterial infectious diseases was determined to be 0.5 ng/ml, which was associated with a sensitivity of 64.4% and specificity of 86.0%. Areas under the receiver operating characteristic curves (POCs) were 0.84 for PCT, 0.60 for endotoxin, 0.77 for IL-6, and 0.78 for CRP in the combined group of patients with bacterial infectious disease and those with nonbacterial infectious disease, and the area under the ROC for PCT was significantly higher than that for endotoxin (P<0.001). In patients diagnosed with bacteremia based on clinical findings, the positive rate of diagnosis with PCT was 70.2%, while that of blood culture was 42.6%. PCT is thus essential for discriminating bacterial infection from SIRS, and is superior in this respect to conventional serum markers and blood culture.

Biomarkers↗

Prospective surveillance of community-onset and healthcare-associated methicillin-resistant Staphylococcus aureus isolated from a university-affiliated hospital in Japan.

We conducted a prospective comparative study of community-onset (CO) and healthcare-associated (HA) methicillin-resistant Staphylococcus aureus(MRSA) strains between 2000 and 2001 at Tokyo Women's Medical University Hospital (1,500 beds) in Japan. Of the 172 consecutive MRSA isolates analyzed, 13 (8%) were categorized as CO-MRSA. The mean age of patients with CO-MRSA was significantly younger than that of patients with HA-MRSA. Most CO-MRSA strains were isolated from skin and more likely to be susceptible to erythromycin, clindamycin, tetracycline, levofloxacin, and spectinomycin compared to HA-MRSA isolates. Pulsed-field gel electrophoresis (PFGE) analysis, staphylococcal cassette chromosome mec(SCCmec) typing, and multi-locus sequence typing (MLST) revealed that CO-MRSA strains were divided into the following multi-clones: 3 clone A: II: ST5 (PFGE type: SCCmec type: MLST sequence type); 1 L: II: ST5; 1 H: IV: ST1; 1 I: IV: ST81; 2 D: IV: ST8; 1 B: IV: ST89; 1 B: IV: ST379; and 3 B: IV: ST91. Of the 159 HAMRSA strains, 124 (78%) belonged to a single clone (PFGE clone A: SCCmec type II: tst and sec positive: coagulase type II: multi-drug resistance). Four CO-MRSA strains belonging to PFGE clone B: SCCmec type IV: MLST clonal complex 509 (ST89, 91, 379) had the exfoliative toxin B (etb) genes, but all CO-MRSA and HA-MRSA strains did not possess the Panton-Valentine leukocidin (pvl) genes. These results demonstrate that multiple lineages of CO-MRSA have the potential for dissemination in the community in Japan.

Adolescent↗

[In vitro susceptibilites to levofloxacin and various antibacterial agents of 11,475 clinical isolates obtained from 52 centers in 2002].

The susceptibilities of bacteria to fluoroquinolones (FQs), especially levofloxacin, and other antimicrobial agents were investigated using 11,475 clinical isolates collected in Japan during 2002. Methicillin susceptible staphylococci, Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis, the family of Enterobactericeae, Haemophilus influenzae and Acinetobacter spp. exhibited stable and high susceptibilities to FQs. The rate of FQs-resistant MRSA was 80 approximately 90%, being markedly higher than that of FQs-resistant MSSA. The FQs-resistance rate of MRCNS was also higher than that of MSCNS, however, it was lower than that of MRSA. No FQs-resistant clinical isolates of Salmonella spp. were detected in any of the surveys. Thirteen of Escherichai coli 696 isolates, 8 of Klebsiella pneumoniae 630 isolates and 33 of Proteus mirabilis 373 isolates produced extended-spectrum beta-lactamase (ESBL), furthermore 6 of 13 in E. coli, 1 of 8 in K. pneumoniae and 14 of 31 ESBL-producing isolates, and in P. mirabilis were FQs resistant. Attention should be focused in the future on the emergence of ESBL in relation to FQs resistance. The rate of FQs-resistant P. aeruginosa isolated from urinary tract infection (UTI) was 40 approximately 60%, while 15 approximately 25% of isolates from respiratory tract infection (RTI) were resistant. IMP-1 type metallo beta-lactamase producing organisms were found in 49 of P. aeruginosa 1,095 isolates, 7 of S. marcescens 586 isolates and 4 of Acinetobacter spp. 474 isolates, respectively. Glycopeptide-resistant enterococci or S. aureus was not found.

Anti-Bacterial Agents↗

[The comparison of optimized pharmacodynamic dosing strategy for meropenem using Monte Carlo simulation].

Monte Carlo simulation was enmloyed to determine pharmacodynamic target attainment rates for several meropenem dosage regimens against E. coli and P. aeruginosa populations. Percent Time above MIC (% T > MIC) exposures for several meropenem dosage regimens were simulated for 10,000 subjects. Variability in pharmacokinetic parameters and MIC distributions were derived from studies in healthy volunteers and the injection antibiotics include of Meropenem susceptibility test surveillance program. The probabilities of attaining bacteriostatic responses (30% T > MIC) and bactericidal responses (50% T > MIC) exposures were high for all dosage regimens against populations of E. coli. Against P. aeruginosa, the 1000 g 3.0 infusion q8 dosage regimen provided the hightest target attainment rates. Further study of these dosage recommendations in clinical trials is suggested.

Adult↗

Molecular confirmation of transmission route of Staphylococcus intermedius in mastoid cavity infection from dog saliva.

We report a case of infection of a mastoid cavity after mastoidectomy had been performed for chronic otitis media with cholesteatoma. The infection was caused by Staphylococcus intermedius after a pet dog had licked the patient's ears. Bacterial strains from the dog's saliva and the otorrhea in the patient were confirmed to be identical by pulsed-field gel electrophoresis analysis. The possibility of an oral transmission route of S. intermedius from pets to humans should be noted.

Animals↗

Optimization of dose and dose regimen of biapenem based on pharmacokinetic and pharmacodynamic analysis.

Pharmacokinetic and pharmacodynamic (PK/PD) parameters, which are important indices of the therapeutic efficacy of antimicrobials, and the minimum inhibitory concentration (MIC) predictive of clinical efficacy at common clinical doses, were examined for biapenem (BIPM; 300 mg b.i.d.), imipenem/cilastatin (IPM/CS; 500 mg/500 mg b.i.d.), meropenem (MEPM; 500 mg b.i.d.), and ceftazidime (CAZ; 1000 mg b.i.d.), using a mouse model of thigh infection caused by Pseudomonas aeruginosa. The PK/PD parameter that most closely correlated with the therapeutic efficacy of all these antimicrobials was time above MIC (T > MIC). The values of T > MIC predictive of clinical efficacy against P. aeruginosa infection varied among antimicrobials and were >/=17%, >/=17%, >/=23%, and >/=33% for BIPM, IPM/CS, MEPM, and CAZ, respectively. From these values and the known plasma concentrations of the antimicrobials in humans after administration at the common clinical doses, the MIC for bacterial strains at which clinical efficacy can be expected was estimated to be </=4.4 microg/ml for BIPM, </=6.1 microg/ml for IPM/CS, </=2.2 microg/ml for MEPM, and </=13.6 microg/ml for CAZ. These MICs nearly coincided with the MIC(80) of the antimicrobials for 104 clinical isolates of P. aeruginosa strains. These results indicate that, even at a low dose, of 300 mg b.i.d., the clinical efficacy of BIPM against P. aeruginosa infection can be expected to be comparable to that of IPM/CS, MEPM, and CAZ.

Animals↗

Evaluation of dot-ELISA for serological diagnosis of amebiasis.

We improved the dot enzyme-linked immunosorbent assay (dot-ELISA) reported by Itoh and Sato, and assessed the usefulness of this test for the diagnosis of amebiasis. The sensitivity of dot-ELISA was compared with that of plate ELISA, the indirect hemagglutination test (IHA), and the indirect fluorescent antibody test (IFA) for the diagnosis of amebiasis. Of 37 serum samples from patients with documented amebiasis, 36 (97.3%) were positive by dot-ELISA. There was consistency among the results of dot-ELISA, plate ELISA, and IFA, although the positive rate of IHA was lower than that of the others (78.4%; 29 of 37 cases were positive). The specificities of dot-ELISA and plate ELISA were assessed using a total of 68 sera, collected from 38 patients infected with seven different parasites other than Entamoeba histolytica, 10 patients showing diarrhea or liver abscess without parasitic infection, and 20 healthy individuals. The two assays showed no false-positive results. There were no differences in sensitivity and specificity between dot-ELISA and plate ELISA. However, the dot-ELISA technique seems to be more feasible for clinical application than plate ELISA techniques, because the assay does not require any specific equipment.

Animals↗

Streptococcus dysgalactiae-derived mitogen (SDM), a novel bacterial superantigen: characterization of its biological activity and predicted tertiary structure.

A mitogenic substance, designated Streptococcus dysgalactiae-derived mitogen (SDM), was purified from S. dysgalactiae culture supernatant, and the gene encoding the mitogen was cloned. Both native and recombinant SDM expressed in Escherichia coli significantly activated human V beta 1+ and V beta 23+ T cells in association with major histocompatibility complex (MHC) class II molecules on accessory cells, indicating that SDM possesses superantigenic properties. The sdm gene consists of two segments encoding a signal peptide and a mature 25 kDa protein composed of 212 amino acids. Three of 34 S. dysgalactiae strains but none of 28 Streptococcus pyogenes strains examined carried sdm. Phylogenetic analysis indicated that SDM belongs to a family distinct from established bacterial superantigens. SDM showed around 30% homology with other superantigens at the amino acid sequence level. The tertiary structure of SDM was predicted by modelling onto streptococcal pyrogenic exotoxin C and streptococcal mitogenic exotoxin Z-2, both of which share highly homologous structure-determining regions. SDM showed overall structural similarity to both these superantigens. This is the first study to characterize fully a bacterial superantigen from S. dysgalactiae.

Amino Acid Sequence↗

Evaluation of a new serotyping kit for Streptococcus pneumoniae.

A new serotyping test kit (Streptococcus pneumoniae antisera "Seiken" set; Denka kit) was evaluated for 285 strains of Streptococcus pneumoniae in comparison with the standard capsular reaction (Quellung test). This new kit is based on the slide-agglutination method and is composed of eight pool sera, 40 group or type sera and 41 specific type sera. All serotyping results by using the Denka kit were completely identical to those obtained by using the conventional Quellung test. For types and groups, sensitivity and specificity were 100 and 100 %, respectively. For specific types, sensitivity and specificity were 100 and 100 %, respectively. The Denka kit is relatively rapid (mean test time, 5 min, versus 15 min by Quellung test), cheap (0.5 US$ per test, versus 1.4 US$ per Quellung test), easy to perform and does not require special equipment. The Denka kit may be useful for fieldworkers in developing countries involved in epidemiological surveys and vaccine development.

Agglutination Tests↗

Molecular epidemiology of methicillin-resistant Staphylococcus aureus strains causing neonatal toxic shock syndrome-like exanthematous disease in neonatal and perinatal wards.

Neonatal toxic shock syndrome-like exanthematous disease (NTED) is a new neonatal disease caused by toxic shock syndrome toxin 1 (TSST-1). We conducted a prospective surveillance study and characterized the methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from patients with NTED and compared them with the strains from patients with other MRSA infections and asymptomatic carriers. The study was performed in the neonatal intensive care unit and a general neonatal and maternal ward in the Tokyo Women's Medical University Hospital (TWMUH) from September to December 1998. Among 103 patients eligible for the study, MRSA was detected in 62 (60.2%) newborns; of these 62 newborns, 8 (12.9%) developed NTED, 1 (1.6%) had another MRSA infection, and 53 (85.5%) were asymptomatic MRSA carriers. Sixty-nine MRSA strains were obtained from the 62 newborns. DNA fingerprinting by pulsed-field gel electrophoresis showed two clusters: clone A with 8 subtypes and clone B. Sixty-seven of the 69 MRSA strains (97.1%) belonged to clone A, and type A1 was the most predominant (42 of 69 strains; 60.9%) in every neonatal and perinatal ward. All but one of the clone A strains had the TSST-1 and staphylococcal enterotoxin C genes. We also analyzed eight MRSA strains from eight NTED patients in five hospitals in Japan other than TWMUH. All the MRSA strains from NTED patients also belonged to clone A. These results suggest that a single clone that predominated in the neonatal wards of six hospitals might have caused NTED. However, the occurrence of NTED might not be dependent on the presence of an NTED-specific strain.

Anti-Bacterial Agents↗

[Tetracycline].

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Anti-Bacterial Agents↗

[Hospital outbreak of viral gastroenteritis attributed to Norwalk-like viruses in Japan].

BACKGROUND: Norwalk-like viruses (NLVs), RNA viruses in the family of Caliciviridae, are known as a pathogen of nonbacterial food-borne gastroenteritis associated with eating raw oysters. NLV can spread from person to person with strong infectivity and can cause large epidemics in communities, schools, nursing homes, and hospitals. Here, we describe an outbreak of gastroenteritis associated with NLVs, possibly introduced from outside the hospital, in four different wards on four different occasions between November 1999 and April 2000, in a university affiliated hospital in Tokyo. METHOD: Total 61 specimens (stool or vomitus) from 46 patients and staffs were collected. Reverse transcription-polymerase chain reaction (RT-PCR) test was performed on each specimen. Standard precautions were applied strictly as control. RESULT: NLV was detected in 40 specimens from 28 patients and staff (20 patients, 8 nurses). Attack rate of the patients were 0.19, nurses were 0.15, and doctors were 0.07. CONCLUSION: The spread of NLV from person to person is considered to be a major infection pathway in each ward. A nurse is at a high risk of infection as a patient in some wards. A stringent policy of control must be applied.

Adult↗