Papers - YASUDA Mitsuru

Prevalence of Mycoplasma genitalium in asymptomatic men in Japan

M Uno, T Deguchi, A Saito, M Yasuda, H Komeda, Y Kawada

INTERNATIONAL JOURNAL OF STD & AIDS ( ROYAL SOC MEDICINE PRESS LTD )  8 ( 4 ) 259 - 260  1997.04  [Refereed]

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We aim to clarify the prevalence of Mycoplasma genitalium in asymptomatic men in Japan. First-catch urine specimens were obtained from 187 asymptomatic Japanese men and examined for the presence of M. genitalium using a polymerase chain reaction (PCR)-based assay. Two (1.1%) of 187 first-catch urine specimens were positive for M. genitalium. The prevalence of M. genitalium in wine specimens of asymptomatic men in Japan is lower than that in asymptomatic men in the UK (6%) and Denmark (9%).

Alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV in quinolone-resistant clinical isolates of Klebsiella pneumoniae

T Deguchi, A Fukuoka, M Yasuda, M Nakano, S Ozeki, E Kanematsu, Y Nishino, S Ishihara, Y Ban, Y Kawada

ANTIMICROBIAL AGENTS AND CHEMOTHERAPY ( AMER SOC MICROBIOLOGY )  41 ( 3 ) 699 - 701  1997.03  [Refereed]

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We determined a partial sequence of the Klebsiella pneumoniae parC gene, including the region analogous to the quinolone resistance-determining region of the Escherichia coli gyrA gene, and examined 26 clinical strains of K. pneumoniae for an association of alterations in GyrA and ParC with susceptibilities to quinolones; The study suggests that in K. pneumoniae DNA gyrase is a primary target of quinolones and that ParC alterations play a complementary role in the development of higher-level fluoroquinolone resistance.

Antimicrobial activity of a new fluoroquinolone, DU-6859a, against quinolone-resistant clinical isolates of Neisseria gonorrhoeae with genetic alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV

T Deguchi, M Yasuda, M Nakano, E Kanematsu, S Ozeki, S Ishihara, Saito, I, Y Kawada

JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY ( OXFORD UNIV PRESS )  39 ( 2 ) 247 - 249  1997.02  [Refereed]

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The in-vitro antimicrobial activity of DU-6859a, a new fluoroquinolone, was tested against 55 clinical isolates of Neisseria gonorrhoeae. The MIC of DU-6859a inhibiting 90% (MIC90) of the isolates with genetic alterations of both the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV was 0.125 mg/L. The MIC90, for isolates with alterations of GyrA alone or without alterations of GyrA or ParC was 0.03 mg/L and 0.004 mg/L, respectively. The potency of DU-6859a against clinical isolates bearing genetic alterations associated with quinolone resistance was significantly greater than that of currently available fluoroquinolones.

Prevalence of Mycoplasma genitalium in men with gonococcal urethritis

M Uno, T Deguchi, H Komeda, M Yasuda, M Tamaki, S Maeda, Saito, I, Y Kawada

INTERNATIONAL JOURNAL OF STD & AIDS ( ROYAL SOC MEDICINE SERVICES LTD )  7 ( 6 ) 443 - 444  1996.10  [Refereed]

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A significant association of Mycoplasma genitalium with non-gonococcal urethritis has been reported, but the prevalence of this mycoplasma in men with gonococcal urethritis has not been so well studied. Ln this study, we examined urethral swab specimens from 45 Japanese male patients with gonococcal urethritis for the presence of M. genitalium by using a polymerase chain reaction-based assay. We also sought Chlamydia trachomatis by an enzyme immunoassay (Chlamydiazyme). Of the 45 specimens, 2 (4.4%) were positive for the mycoplasma and 12 (26.7%) were positive for C. trachomatis. The findings suggest that M. genitalium may be a cause not only of non-gonococcal urethritis but also of postgonococcal urethritis.

Rapid detection of point mutations of the Neisseria gonorrhoeae gyrA gene associated with decreased susceptibilities to quinolones

T Deguchi, M Yasuda, M Nakano, S Ozeki, T Ezaki, SI Maeda, Saito, I, Y Kawada

JOURNAL OF CLINICAL MICROBIOLOGY ( AMER SOC MICROBIOLOGY )  34 ( 9 ) 2255 - 2258  1996.09  [Refereed]

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Mutations in the gyrA gene resulting in amino acid changes at Ser-91 and Asp-95 are significantly associated with decreased susceptibilities to quinolones in Neisseria gonorrhoeae. To detect these mutations, we developed a rapid and simple assay based on amplification of the region of the gyrA gene containing the mutation sites by PCR and digestion of the PCR product with a restriction enzyme. A naturally occurring HinfI restriction site was present in the region containing the Ser-91 codon, and an artificial HinfI restriction site was created in the region containing the Asp-95 codon by the method of primer-specified restriction site modification. The mutations generating alterations at Ser-91 and Asp-95 were detected as restriction fragment length polymorphisms of the PCR products digested with HinfI. Fifty-five clinical strains of N. gonorrhoeae were examined for mutations in the gyrA gene by this method. Mutations at Ser-91 and/or Asp-95 were detected in all the 31 strains in which the mutations had been confirmed by DNA sequencing. Our method allows simultaneous testing of a large number of Strains and provides results within 8 h. This rapid and simple assay could be a useful screening device for genetic alterations associated with decreased susceptibilities to quinolones in N. gonorrhoeae and could facilitate epidemiological studies on clinical isolates of N. gonorrhoeae with decreased susceptibilities to quinolones.

Comparison among performances of a ligase chain reaction-based assay and two enzyme immunoassays in detecting Chlamydia trachomatis in urine specimens from men with nongonococcal urethritis

T Deguchi, M Yasuda, M Uno, K Tada, H Iwata, H Komeda, S Maeda, Latila, V, Saito, I, Y Kawada

JOURNAL OF CLINICAL MICROBIOLOGY ( AMER SOC MICROBIOLOGY )  34 ( 7 ) 1708 - 1710  1996.07  [Refereed]

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We evaluated the performances of a ligase chain reaction (LCR)-based assay and two enzyme immunoassays (Chlamydiazyme and IDEIA) in the detection of Chlamydia trachomatis in urine specimens. We compared the results of testing urine specimens by these assays with those of urethral swab culture by examining samples from 131 men with nongonococcal urethritis. Discrepant results were analyzed by testing urethral swab specimens for C. trachomatis by a PCR-based assay. After the resolution of discrepant results, the sensitivity of urethral swab culture was 85.3%, whereas those of the LCR assay, Chlamydiazyme, and IDEIA with urine specimens were 93.1, 82.4, and 94.1%, respectively. The LCR assay and IDEIA were more sensitive than was urethral swab culture. In addition, the LCR assay, with a sensitivity equal to that of IDEIA, was more specific. Overall, the LCR assay proved to be superior to the enzyme immunoassays in detecting C. trachomatis in urine specimens. Testing urine specimens by LCR assay should be a helpful alternative method for diagnosing C. trachomatis urethral infection in men with nongonococcal urethritis.

Quinolone-resistant Neisseria gonorrhoeae: Correlation of alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV with antimicrobial susceptibility profiles

T Deguchi, M Yasuda, M Nakano, S Ozeki, T Ezaki, Saito, I, Y Kawada

ANTIMICROBIAL AGENTS AND CHEMOTHERAPY ( AMER SOC MICROBIOLOGY )  40 ( 4 ) 1020 - 1023  1996.04  [Refereed]

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Fifty-five clinical strains of Neisseria gonorrhoeae were examined for mutations in the gyrA and parC genes and for antimicrobial susceptibility profiles. The MICs of quinolones for 31 strains with alterations in GyrA were significantly higher than the MICs for 24 strains without such alterations. Eleven strains with alterations in both GyrA and ParC were significantly more resistant to fluoroquinolones than those with alterations in GyrA alone. The MICs of cephalosporins for these strains were also significantly higher than those for other strains.

腎細胞癌におけるProgesterone receptorの発現に関する免疫組織学的検討

楊 睦正, 江原 英俊, 出口 隆, 仲野 正博, 安田 満, 土屋 博, 河田 幸道

日本泌尿器科学会雑誌 ( 一般社団法人 日本泌尿器科学会 )  87 ( 2 ) 390 - 390  1996

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Detection of <I>Mycoplasma genitalium</I> from Male Patients with Non-Gonococcal Urethritis by Polymerase Chain Reaction

KOMEDA Hisao, DEGUCHI Takashi, YASUDA Mitsuru, TADA Kouji, IWATA Hideki, ISHIHARA Satoshi, BAN Yoshihito, KAWADA Yukimichi, ESAKI Takayuki, SAITO Isao

Journal of the Japanese Association for Infectious Diseases ( The Japanese Association for Infectious Diseases )  68 ( 11 ) 1376 - 1380  1994

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Mycoplasma genitalium causes urethritis in non-human primates, but studies on its pathogenicity in man have been hampered by the difficulty in isolating this oragnism in culture. We have used a specific polymerase chain reaction to examine the role of M. genitalium in nongonococcal urethritis (NGU). Oligonucleotide primers were used to amplify a 281 bp of 140-KDa adhesin gene of M. genitalium. A characteristic PCR product was amplified, when M. genitalium DNA was template for the PCR. No amplified product was detected in Mycoplasma pneumoniae DNA, Mycoplasma hominis DNA or other bacterial DNAs. M. genitalium DNA was detected in urethral swabs from 17 (14.9%) of 114 men with NGU. Three (9.1%) of the 33 men with Chlamydia-positive NGU and 14 (17.3%) of the 81 with Chlamydia-negative NGU were positive for M. genitalium DNA, but 29 men without urethritis were negative. The prevalence of M. genitalium in NGU and in Chlamydia-negative NGU was significantly higher than that in the normal control. These findings suggest that M. genitalium would be a cause of NGU.

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