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S Ichiyama

Publications and source records attributed to S Ichiyama.

At least 73 records · Page 4Linked to original sources
PubMed1997

Mycobacterium growth indicator tube testing in conjunction with the AccuProbe or the AMPLICOR-PCR assay for detecting and identifying mycobacteria from sputum samples.

We have compared the ability of the Mycobacterium Growth Indicator Tube (MGIT) system, a new culture method with an oxygen-sensitive fluorescent sensor, to recover mycobacteria from sputum samples with the abilities of egg-based medium and the Septi-Chek AFB system. We have also assessed the clinical utility of the AccuProbe or the AMPLICOR-PCR assay to directly identify Mycobacterium tuberculosis complex and M. avium-M. intracellulare complex (MAC) from positive MGITs. From 382 sputum samples, 99 isolates of M. tuberculosis complex and 20 isolates of MAC were recovered. The MGIT system had the highest recovery rates for M. tuberculosis complex (97.0%) and MAC (100%), compared to recovery rates of 51.5 and 65.0%, respectively, with the egg-based medium and 81.8 and 85.0%, respectively, with the Septi-Chek AFB system. The shortest recovery times were also achieved with the MGIT system: 16.6 days for M. tuberculosis complex and 12.0 days for MAC, compared to 27.1 and 20.1 days, respectively, with the egg-based medium and 21.4 and 13.2 days, respectively, with the Septi-Chek AFB system. The AccuProbe identified 74 (77.1%) of the 96 M. tuberculosis complex-positive MGITs and 17 (85.0%) of the 20 MAC-positive vials. The AMPLICOR system correctly identified 94 (97.9%) of the 96 M. tuberculosis complex-positive MGITs and all 20 MAC-positive vials. Therefore, the MGIT system used in conjunction with the AMPLICOR system is a rapid and sensitive method for detecting and identifying M. tuberculosis complex and MAC isolates from sputum samples.

DNA, Bacterial↗
PubMed1997

Campylobacter fetus subsp. fetus cholecystitis in a patient with advanced hepatocellular carcinoma.

Acute cholecystitis due to Campylobacter fetus subsp. fetus is very uncommon. We report a case of cholecystitis and obstructive jaundice in which cultured bile grew this organism. The patient had a 4-year history of hepatocellular carcinoma, resulting in common bile duct obstruction due to abdominal lymph node metastasis. Microscopic examination of her bile showed multiple Gram-negative curved organisms and C. fetus subsp. fetus was isolated under microaerophilic conditions. Therefore, we should be aware of this organism and use microaerophilic culture in association with the result of microscopic examination of bile specimens.

Campylobacter Infections↗
PubMed1996

Types of methicillin-resistant Staphylococcus aureus associated with high mortality in patients with bacteremia.

Forty-seven strains of methicillin-resistant Staphylococcus aureus (MRSA) isolated from 47 patients with bacteremia were analyzed by chromosomal DNA digestion pattern using pulsed-field gel electrophoresis and evaluated for serological coagulase type, enterotoxin type, and toxic shock syndrome toxin-1 production. The mortality rate was significantly higher in the older patients (> or = 51 years of age) than in the younger patients (< or = 50 years of age) (50% vs. 4%, p = 0.0007). Methicillin-resistant Staphylococcus aureus strains of serological coagulase type II were more likely to be associated with mortality in older patients than were strains of the other types (p = 0.037).

Adolescent↗
PubMed1996

Comparison of DNA fingerprinting by PFGE and PCR-RFLP of the coagulase gene to distinguish MRSA isolates.

Staphylococcus aureus isolates were collected from epidemiologically unrelated clinical sources in Japan between 1991 and 1993. A total of 40 isolates, five each of eight coagulase types, were analysed by polymerase chain reaction (PCR) of the coagulase gene, PCR-restriction fragment length polymorphism (RFLP) after AluI digestion, and pulsed-field gel electrophoresis (PFGE) of chromosomal DNA after SmaI digestion. The efficiency of discrimination among the isolates increased in the order of PCR < PCR-RFLP < PFGE, yielding five, 13 and 31 different types, respectively. To assess the clinical use of these methods, 42 additional methicillin-resistant S. aureus (MRSA) isolates collected from 27 inpatients in a hospital were analysed. PFGE and PCR-RFLP were able to discriminate 11 and four types, respectively. PFGE analysis detected cross-infection between four postoperative patients in an intensive-care unit, and in six neonates in intensive care. We conclude that of the three methods tested, PFGE analysis currently allows the most effective discrimination of MRSA strains.

Bacterial Typing Techniques↗
PubMed1996

Detection of human cytomegalovirus DNA from allogeneic bone marrow transplant recipients with interstitial pneumonitis.

Interstitial pneumonitis (IP) due to human cytomegalovirus (HCMV) infection can kill patients who receive allogeneic bone marrow transplants (BMT). However, making a definitive diagnosis of HCMV-associated IP is difficult, except in pathologically defined cases. The authors tried to detect HCMV DNA amplified by the polymerase chain reaction with nonradioactive Southern blot analysis from paraffin-embedded lung tissue. Human cytomegalovirus DNA was detected in all of ten BMT recipients with IP and all of three non-BMT recipients with histologically diagnosed HCMV IP. Clinical diagnoses indicated that three of ten allogeneic BMT recipients had HCMV IP, and they showed amplified HCMV DNA despite the lack of histologic viral inclusions. However, HCMV DNA was not detected in 11 immunosuppressed patients with non-HCMV pneumonitis who were included as controls. These observations indicate that the polymerase chain reaction and Southern blot analysis used with lung tissue is more sensitive than histologic examination, and that these tests may be applicable to transbronchial lung biopsy specimens for the early specific diagnosis of HCMV IP. Further analysis of allogeneic BMT recipients showed that four patients who died of HCMV IP fewer than 90 days after BMT had higher quantities of HCMV DNA, whereas six patients who died of HCMV IP more than 90 days after BMT showed lower quantities of HCMV DNA. THis result suggests that HCMV IP in the late phase after MBT might not be attributable to active virus replication alone but rather to the immune response involved in the graft-versus-host reaction.

Base Sequence↗
PubMed1996

Multifocal outbreaks of metallo-beta-lactamase-producing Pseudomonas aeruginosa resistant to broad-spectrum beta-lactams, including carbapenems.

A total of 3,700 Pseudomonas aeruginosa isolates were collected from 17 general hospitals in Japan from 1992 to 1994. Of these isolates, 132 carbapenem-resistant strains were subjected to DNA hybridization analysis with the metallo-beta-lactamase gene (blaIMP)-specific probe. Fifteen strains carrying the metallo-beta-lactamase gene were identified in five hospitals in different geographical areas. Three strains of P. aeruginosa demonstrated high-level imipenem resistance (MIC, > or = 128 micrograms/ml), two strains exhibited low-level imipenem resistance (MIC, < or = 4 micrograms/ml), and the rest of the strains were in between. These results revealed that the acquisition of a metallo-beta-lactamase gene alone does not necessarily confer elevated resistance to carbapenems. In several strains, the metallo-beta-lactamase gene was carried by large plasmids, and carbapenem resistance was transferred from P. aeruginosa to Escherichia coli by electroporation in association with the acquisition of the large plasmid. Southern hybridization analysis and genomic DNA fingerprinting profiles revealed different genetic backgrounds for these 15 isolates, although considerable similarity was observed for the strains isolated from the same hospital. These findings suggest that the metallo-beta-lactamase-producing P. aeruginosa strains are not confined to a unique clonal lineage but proliferated multifocally by plasmid-mediated dissemination of the metallo-beta-lactamase gene in strains of different genetic backgrounds. Thus, further proliferation of metallo-beta-lactamase-producing strains with resistance to various beta-lactams may well be inevitable in the future, which emphasizes the need for early recognition of metallo-beta-lactamase-producing strains, rigorous infection control, and restricted clinical use of broad-spectrum beta-lactams including carbapenems.

Blotting, Southern↗
PubMed1996

Evaluation of Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test and Roche PCR-microwell plate hybridization method (AMPLICOR MYCOBACTERIUM) for direct detection of mycobacteria.

We evaluated the clinical utility of an rRNA amplification-based Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (AMTD) system and a PCR-based Roche AMPLICOR MYCOBACTERIUM system for direct detection of Mycobacterium tuberculosis, M. avium, and M. intracellulare. Of the 422 sputum samples from 170 patients, 137 (121 of M. tuberculosis, 14 of M. avium-M. intracellulare complex [MAC], 2 of mycobacterium other than M. tuberculosis or MAC) were culture positive with the Septi-Chek AFB system. One sample of a contaminated culture results was excluded for further analyses. The AMTD system detected all of the 121 samples which grew M. tuberculosis (sensitivity, 100%). Of the 284 culture negative samples, 28 were positive by this system (specificity, 90.1%). After resolution of the discrepant samples, based on a positive history for culture of the patient, the specificity of this system increased to 99.3%. On the other hand, the AMPLICOR system gave a positive result for 132 out of the 135 culture positive samples for M. tuberculosis or MAC (sensitivity, 97.8%). Of the 284 culture-negative samples, 37 were positive by this system (specificity, 87.0%). The specificity for this system after resolution of the discrepant samples increased to 98.9%. The agreement between the results from the AMTD system and the AMPLICOR system was 98.7%. Both of the systems are highly sensitive and specific for detecting M. tuberculosis and/or MAC directly from sputum samples within hours, and they should be recommended for routine use in the clinical microbiology laboratory.

Bacteriological Techniques↗
PubMed1996

PCR detection of metallo-beta-lactamase gene (blaIMP) in gram-negative rods resistant to broad-spectrum beta-lactams.

We applied PCR to the rapid detection of the metallo-beta-lactamase gene, blaIMP, in clinically isolated gram-negative rods. A total of 54 high-level ceftazidime-resistant strains (MICs, > 128 micrograms/ml) were subjected to PCR analyses with the blaIMP-specific primers, since the blaIMP-bearing clinical isolates tested in our previous study always demonstrated high-level resistance to ceftazidime. Twenty-two blaIMP-positive strains including 9 Pseudomonas aeruginosa, 9 Serratia marcescens, 2 Alcaligenes xylosoxidans, 1 Pseudomonas putida, and 1 Klebsiella pneumoniae strains were newly identified from 18 different hospitals in Japan. These strains were mostly isolated from urine samples and showed high-level resistance to almost every cephem, while their levels of resistance to carbapenems were diverse. The PCR analyses with novel integrase gene-specific (intI3) and acc(6')-Ib gene-specific primers suggested that the integron structure found in a large plasmid harbored by S. marcescens AK9373 was also well conserved among blaIMP-positive strains. These results imply that the blaIMP gene cassettes have been dispersing into various gram-negative rods with the help of the newly identified integron element. Thus, the PCR-aided rapid detection will be helpful for the early recognition of emerging blaIMP-positive clinical isolates which demonstrate consistent resistance to beta-lactams.

Alcaligenes↗
PubMed1996

Evaluation of immunochromatographic assay systems for rapid detection of hepatitis B surface antigen and antibody, Dainascreen HBsAg and Dainascreen Ausab.

We evaluated two immunochromatographic assays (ICAs), Dainascreen HBsAg for detecting human hepatitis hepatitis B surface antigen (HBsAg) and Dainascreen Ausab for detecting human hepatitis B surface antibody (anti-HBs) in human serum. The ICA systems are composed of a comb-shaped device that contains nitrocellulose strips on which complexes of HBsAg and anti-HBs can be visualized. The results can be read within 15 min of incubation. The limit of detection for HBsAg was 3.1 ng/ml and that for anti-HBs was 42 mIU/ml. Results of HBsAg detection agreed completely with those of conventional enzyme immunoassays (EIAs) and showed a 100% sensitivity (158 of 158 samples) and a 100% specificity (304 of 304 samples). The Dainascreen Ausab detected 184 of the 199 EIA-positive samples (sensitivity, 92.5%) and yielded 6 positive results among the 281 EIA-negative samples (specificity, 97.9%). The ICA systems are rapid and sensitive methods for detecting HBsAg and anti-HBs. They are low-cost systems that need no complex instrumentation for analysis and can be recommended for routine use in clinical microbiology laboratories.

Chromatography↗
PubMed1996

Interleukin-8 activity correlates with histological severity in Helicobacter pylori-associated antral gastritis.

OBJECTIVES: To examine the background histology, interleukin-8 (IL-8) secretion, and expression of IL-8 mRNA and protein, using the gastric antral mucosa infected with Helicobacter pylori. METHODS: The antral biopsies were obtained from an area of endoscopically intact mucosa in 147 patients whose endoscopic diagnoses were normal (n = 41), duodenal ulcer (n = 58), gastric ulcer (n = 21), or gastritis (n = 27). Levels of IL-8 secreted in the organ cultures of mucosal biopsies were measured by an ELISA assay, and the expression of IL-8 mRNA and protein was analyzed in fresh biopsy tissues with RT-PCR and immunofluorescent microscopy, respectively. RESULTS: Significantly greater levels of IL-8 were secreted in patients with H. pylori infection, and its elevation was more prominent in duodenal ulcer patients than in those with gastric ulcer or endoscopically defined gastritis. There was an association among H. pylori density, IL-8 activity, and histological severity of activity and inflammation of gastritis in the Sydney system. Consistent with enhanced IL-8 activity in the organ cultures, IL-8 mRNA was detected in 16 of 23 fresh biopsy tissues studied in H. pylori-positive patients. In contrast, IL-8 transcript was detected in only one of 12 H. pylori-negative cases. Immunofluorescent microscopy showed localization of IL-8 protein in the gastric epithelial cells and lamina propria cells, primarily CD68+ macrophages in specimens with H. pylori infection. CONCLUSIONS: This study indicates that a strong correlation exists between mucosal IL-8 activity and histological severity in H. pylori-associated antral gastritis. Further studies will be necessary to determine the mechanisms involved in elevated mucosal IL-8 activity in H. pylori infection.

Adult↗
PubMed1996

[Recent advances in diagnostic microbiology for mycobacterial infections].

Definitive diagnosis of tuberculosis continues to depend on microscopy and culture. Since routine diagnostic methods are insensitive and time-consuming (3 to 8 weeks), the development of more sensitive and rapid tests is desirable. More sensitive liquid media, radiometric BACTEC system and nonradiometric Septi-Chek AFB system are currently used in clinical laboratories. Advances in DNA techniques have provided a new approach to rapid diagnosis of mycobacterial diseases. Species-specific DNA probes for identifying Mycobacterium tuberculosis complex, M. avium, M. intracellulare, M. kansasii, and M. gordonae from cultures of acid-fast microorganisms are now commercially available. Amplification techniques such as polymerase chain reaction (PCR) provide rapid methods for detecting mycobacterial DNA or RNA directly from clinical samples. Two amplification kits, an rRNA amplification-based Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test system and a PCR-based Roche AMPLICOR MYCOBACTERIUM system, are commercially available. These systems have the speed, reliability and requisite diagnostic capability for detecting mycobacteria directly from clinical specimens.

DNA Probes↗
PubMed1995

[A case of Acanthamoeba keratitis after operation for cataract].

Acanthamoeba keratitis occurs mainly in contact lens users. We experienced a patient with Acanthamoeba keratitis after operation for cataract. A 70-year-old male, who suffered from suppurative keratitis with impairment of visual acuity and eye pain in the left eye after the operation, was admitted to our hospital. After admission he received treatment with oral and topical antibiotics without any improvement. Neither bacterial or fungal pathogens was detected from corenal skrappings. Blue stained Acanthamoeba cysts were detected with the Parker ink KOH preparation from punctured fluid of the anterior chamber of the eye. Acanthamoeba cysts were also cultured on a nonnurient agar plate with Escherichia coli. Then he was treated with oral and topical miconazole and topical fluconazole. His visual acuity did not improve because of the lag of appropriate treatment. Therefore, attention must be paid for the existence of Acanthamoeba keratitis after ophthalmologic operations.

Acanthamoeba Keratitis↗
PubMed1995

Detection of Pneumocystis carinii, Mycobacterium tuberculosis, and cytomegalovirus in human immunodeficiency virus (HIV)-infected patients with hemophilia by polymerase chain reaction of induced sputum samples.

The purpose of this study was to diagnose the initial stage of acute pulmonary infections due to Pneumocystis carinii (P. carinii), Mycobacterium tuberculosis (M. tuberculosis), and cytomegalovirus (CMV) by polymerase chain reaction (PCR) combined with the induced sputum method in hemophilia patients infected with human immunodeficiency virus (HIV). Induced sputum and PCR were obtained at each outpatient visit or when any respiratory symptoms were present during a one-year period. All patients with a CD4+ count of less than 200 x 10(6)/l were given prophylactics against P. carinii pneumonia (PCP). PCR was conducted 111 times in 29 patients. M. tuberculosis DNA was detected in 1 patient and CMV DNA in 4 patients. P. carinii DNA was not detected. PCR on induced sputum samples is sensitive for the rapid detection of the initial stage of respiratory events. PCP prophylaxis changes the clinical manifestations of HIV infection.

AIDS-Related Opportunistic Infections↗
PubMed1995

[Hospital management and the role of clinical microbiology laboratory for preventing nosocomial infection].

Nosocomial infection is a serious issue in the hospital management. Countermeasures for this issue have been discussed from various points including clinical and laboratory medicine, nursing as well as hospital administration. This issue is of great importance to those of us medical practitioners, who engage in diagnosis and treatment of infectious diseases. The role of clinical microbiology laboratories for prevention of nosocomial infection includes performing epidemiological survey, giving information and education, and training and instruction to medical staff. In order to instruct and inspect the countermeasures against nosocomial infection, it is necessary to have a dedicated team in the hospital. We have organized an infection control team(ICT) to collect information and offer training and instruction regarding nosocomial infection. The ICT activities include 1) inspecting if the nosocomial infection control manual is followed correctly, 2) reporting the results of epidemiological survey regarding nosocomial infection, 3) offering the information regarding antimicrobial agents and disinfectants, 4) offering the information regarding the isolation of microorganisms in the hospital and their antimicrobial sensitivities, 5) cost calculation for nosocomial infection control.

Cross Infection↗