Biomedical subjects

Zenzo Nagasawa

Publications and source records attributed to Zenzo Nagasawa.

8 recordsLinked to original sources

PubMed2005

Quantitative microarray-based DNA-DNA hybridization assay for measuring genetic distances among bacterial species and its application to the identification of family Enterobacteriaceae.

Quantitative DNA-DNA hybridization to measure the genetic distances among bacterial species is indispensable for taxonomical determination. In the current studies, we developed a method to determine bacterial DNA relatedness on a glass microarray. Reference DNAs representing a total 93 species of Enterobacteriaceae were arrayed on a glass microplate, and signal intensities were measured after 2 hr of hybridization with Cy3-labeled bacterial DNAs. All immobilized DNAs from members of the family Enterobacteriaceae were identified by this method except for DNAs from Yersinia pseudotuberculosis and Y. pestis. These results suggest that quantitative microarray hybridization could be an alternative to conventional DNA-DNA hybridization for measuring chromosome relatedness among bacterial species.

DNA, Bacterial↗

PubMed2005

[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↗

PubMed2004

A rapid antimicrobial susceptibility test based on chemiluminescence assay and its application to screening of genotypes in vancomycin-resistant enterococci.

Minimum inhibitory concentrations (MICs) of vancomycin (VCM) and teicoplanin (TEIC) were measured using a novel susceptibility test based on the chemiluminescence assay (CA) method (Rapid-Lumi Eiken; Eiken Chemicals, Tokyo, Japan) against 33 strains in total: 7, 5, and 10 strains of which are VCM-resistant enterococci (VRE) with vanA, vanB, and vanC genes, respectively, and the other 11 strains are vancomycin-susceptible enterococci (VSE). The results were in good accordance with the values determined by the standard broth dilution method approved by the National Committee for Clinical Laboratory Standards (NCCLS): i.e., 88% (29/33) of consistency for VCM and 97% (32/33) for TEIC, respectively. In addition, genotypes in VRE strains (vanA, vanB, vanC-1, and vanC-2/3 genes) were properly estimated from the results of the CA method and the NCCLS interpretive categories, even though the incubation time was very short (2-4 h). In conclusion, it was found that the new method is reliable and rapid to detect VRE strains in clinical laboratories.

Anti-Bacterial Agents↗

PubMed2004

[Molecular epidemiologic analysis of nosocomocal infection due to TEIC resistant MRSA strains].

We performed epidemiologic study of 109 strains of methicillin resistant Staphylococcus aureus (MRSA) which were detected in our hospital. Of these strains, 6 strains showed resistant to Teicoplanin (TEIC) which MIC level were between 4 to 8microg/mL. All of them showed some phenotype, such as type II of coagulase, type A of enterotoxin, and were producing TSST-1. Genotype analysis by PFGE also showed that those strains ware identical. From analyzing the spreading rout of these TEIC resistant MRSA, we speculate that they first were in ICU ward, then spread all over the hospital carried by the stuff cross-working ICU and other units of hospital.

Aged↗

PubMed2004

[The isolation frequency and antimicrobial susceptibility of Haemophilus influenzae isolated in Saga University Hospital].

Isolation frequency and antimicrobial susceptibility of Haemophilus influenzae isolated in Saga University hospital from October 2002 to September 2003 were investigated. Out of 155 H. influenzae strains subjected 77 were isolated from pediatrics specimens. beta-Lactamase negative ampicillin (ABPC)-resistant H. influenzae (BLNAR), against which MICs of ABPC were higher than 4 microg/mL, were 32 strains (20.6%), and it became 63 strains (41.3%) when Low-BLNAR, against which MICs of ABPC were higher than 2 microg/mL, were included. beta-Lactamase positive ABPC-resistant H. influenzae (BLPAR) were 8 strains (5.2%). Although those BLNAR were also resistant to variety of beta-lactams, fluoroquinolones and other antibiotics were not affected by the level of ABPC-resistance. Resistant strains of BLPAR against SBT/ABPC, a combination of a beta-lactamase inhibitor, were detected but all of them were sensitive to TAZ/PIPC, an another combination. Those strains were able to be considered as beta-lactamase positive amoxicillin-clavulanate resistant H. influenzae (BLPACR). PIPC, TAZ/PIPC, CTRX, CDTR, MEPM, LVFX and CPFX showed good activity among tested antibiotics.

Adolescent↗

PubMed2003

[Antibacterial activity of oral Cephems against various clinically isolated strains].

We determined the antibacterial activities of oral Cephems against isolated from the patients with the respiratory infections, the urinary tract infections, and infections in the obstetrics field of an adult and a child, during the period from 2002 to 2003; Streptococcus pyogenes, Streptococcus pneumoniae, Haemophilus influenzae, Branhamella catarrhalis, Klebsiella pneumoniae and Escherichia coli of 40 strains of each, and Peptostreptococcus spp. 22 strains. S. pneumoniae and H. influenzae strains that resistant is regarded were collected mainly, penicillin-intermediate S. pneumoniae (PISP), penicillin-resistant S. pneumoniae (PRSP) and beta-lactamase negative ampicillin-resistant H. influenzae (BLNAR) strains. The MICs of Cephems except cefaclor (CCL) were < or = 0.03 microgram/mL against all strains of S. pyogenes. The MICs of cefteram (CFTM) and cefditoren (CDTR) were < or = 0.0125 microgram/mL activity against 7 strains penicillin-susceptible S. pneumoniae (PSSP). However the MIC90s of cefditoren (CDTR) was 1 microgram/mL, cefteram (CFTM), and cefcapene (CFPN) were 2 micrograms/mL against PISP and PRSP, were higher than those of other drugs, but showed slightly higher than PSSP. The MIC90s of Cephems. were 0.5-4 micrograms/mL against strains of E. coli. The MIC90s of CFTM was 0.5 microgram/mL, and CDTR, CFPN were 1 microgram/mL against E. coli were higher than those of other drugs. The four strains of E. coli however were highly-resistant which MIC90s of CCL were more than 32 micrograms/mL were obtains. Furthermore it is necessary to pay much attention to the trend of resistant such as E. coli of Cephems. Although all strains showed resistant to AMPC, MIC90 of Cephems were 0.25-1 microgram/mL, good activities against K. pneumoniae. Against beta-lactamase negative ampicillin-susceptible H. influenzae (BLNAS) 23 strains the MIC90s of CCL and other Cephems were 64 micrograms/mL and 0.25-8 micrograms/mL. The MIC90s of CDTR and CFTM were < or = 1 microgram/mL of BLNAR (15 strains). However there of CFDN and CPDX were 8 micrograms/mL and CCL were > or = 16 micrograms/mL. Two strains which were produced beta-lactamase were highly--ABPC resistant. Although B. catarrhalis all strains were produced beta-lactamase and Cephems except for CCL showed better susceptibility than AMPC. The MIC90s of Cephems were 0.25-2 micrograms/mL against Peptostreptococcus spp.

Administration, Oral↗

PubMed2002

Pulmonary colonization by Chrysosporium zonatum associated with allergic inflammation in an immunocompetent subject.

We report a case of noninvasive pulmonary disease due to Chrysosporium zonatum in an immunocompetent male. The fungus colonized an existing tuberculous cavity and was isolated from transbronchial lavage fluid and from a percutaneous aspiration specimen. The disease was accompanied by the unusual feature of an allergic reaction. The fungus ball was successfully treated by intracavitary administration of amphotericin B. C. zonatum is the anamorph of the heterothallic ascomycete Uncinocarpus orissi, and the identity of the case isolate was verified by formation of ascospores in mating tests with reference isolates.

Aged↗

PubMed2002

[Complicated urinary tract infections--from the perspective of the medical technologist].

We would like to propose re-establishment of the protocol for ordering a clinical microbiology laboratory test after a bedside screening test using urine reagent strip when urinary tract infection is suspected. Media for isolation shall be chosen by the clinical microbiology laboratory after checking turbidity and microscopic examination of the urine specimen. In cases of complicated urinary tract infections, quantitative culture should be performed to investigate changes in the number of microorganism to grasp condition of super infection. In such infections, there are many cases in which multiple microorganism growth including glucose non-fermenting gram-negative bacilli can be recognized. Therefore, it is necessary to inspect colonies on media as long as possible (24 hrs culture may be short in some cases). The protocol for microorganism identification and susceptibility test for such specimen varies in each laboratory, considering the Health Insurance Point System (reimbursement system by MHW). It is necessary to communicate with physicians and to refer to past results to proceed with the laboratory test properly. Therefore, a Certified Clinical Microbiology Medical Technologist is needed and the role played by such staff is important.

Bacteriological Techniques↗