Shoichi Onodera

Mosaic-Like Structure of Penicillin-Binding Protein 2 Gene (penA) in Clinical Isolates of Neisseria gonorrhoeae with Reduced Susceptibility to Cefixime

ABSTRACT Neisseria gonorrhoeae strains with reduced susceptibility to cefixime (MICs, 0.25 to 0.5 μg/ml) were isolated from male urethritis patients in Tokyo, Japan, in 2000 and 2001. The resistance to cephems including cefixime and penicillin was transferred to a susceptible recipient, N. gonorrhoeae ATCC 19424, by transformation of the penicillin-binding protein 2 gene (penA) that had been amplified by PCR from a strain with reduced susceptibility to cefixime (MIC, 0.5 μg/ml). The sequences of penA in the strains with reduced susceptibilities to cefixime were different from those of other susceptible isolates and did not correspond to the reported N. gonorrhoeae penA gene sequences. Some regions in the transpeptidase-encoding domain in this penA gene were similar to those in the penA genes of Neisseria perflava (N. sicca), Neisseria cinerea, Neisseria flavescens, and Neisseria meningitidis. These results showed that a mosaic-like structure in the penA gene conferred reductions in the levels of susceptibility of N. gonorrhoeae to cephems and penicillin in a manner similar to that found for N. meningitidis and Streptococcus pneumoniae.

Analysis of amino acid sequences of penicillin-binding protein 2 in clinical isolates of Neisseria gonorrhoeae with reduced susceptibility to cefixime and ceftriaxone

Neisseria gonorrhoeae strains with reduced susceptibility to cefixime and ceftriaxone, with minimum inhibitory concentrations (MICs) of cefixime of 0.125–0.25 μg/ml and ceftriaxone of 0.031–0.125 μg/ml, were isolated from male urethritis patients in Tokyo, Japan, in 2006. The amino acid sequences of PenA, penicillin-binding protein 2, in these strains were of two types: PenA mosaic and nonmosaic strains. In the PenA mosaic strain, some regions in the transpeptidase-encoding domain in PenA were similar to those of Neisseria perflava/sicca, Neisseria cinerea, Neisseria flavescens, Neisseria polysaccharea, and Neisseria meningitidis. In the PenA nonmosaic strain, there was a mutation of Ala-501 to Val in PenA. In addition, we performed homology modeling of PenA wild-type and mosaic strains and compared them. The results of the modeling studies suggested that reduced susceptibility to cephems such as cefixime and ceftriaxone is due to a conformational alteration of the β-lactam-binding pocket. These results also indicated that the mosaic structures and the above point mutation in PenA make a major contribution to the reduced susceptibility to cephem antibiotics.

Questionnaire survey of Japanese urologists concerning the diagnosis and treatment of chronic prostatitis and chronic pelvic pain syndrome

Objectives:  We performed a questionnaire survey to investigate various issues in the diagnosis and treatment of chronic prostatitis/chronic pelvic pain syndrome by Japanese urologists and to clarify the circumstances surrounding prostatitis in Japan.

Renal metastasis of thyroid carcinoma

We report here the sixth known case of metastatic renal tumor of thyroid carcinoma. In 1999, a 37‐year‐old man was referred to us with a left renal mass found incidentally by ultrasound during an annual check‐up. Computed tomography (CT) revealed a well‐defined, hyperdense mass 3 cm in diameter in the middle of the left kidney. Left radical nephrectomy was performed under the preoperative diagnosis of renal cell carcinoma. Histologically, the tumor was metastatic of typical papillary thyroid carcinoma.

Treatment of acute uncomplicated cystitis with faropenem for 3 days versus 7 days: multicentre, randomized, open-label, controlled trial

OBJECTIVES The increasing prevalence of resistant bacteria such as fluoroquinolone-resistant or extended-spectrum β-lactamase-producing strains in pathogens causing acute uncomplicated cystitis has been of concern in Japan. Faropenem sodium is a penem antimicrobial that demonstrates a wide antimicrobial spectrum against both aerobic and anaerobic bacteria. It is stable against a number of β-lactamases. METHODS We compared 3 and 7 day administration regimens of faropenem in a multicentre, randomized, open-label, controlled study. RESULTS In total, 200 female patients with cystitis were enrolled and randomized into 3 day (N = 97) or 7 day (N = 103) treatment groups. At the first visit, 161 bacterial strains were isolated from 154 participants, and Escherichia coli accounted for 73.9% (119/161) of bacterial strains. At 5-9 days after the completion of treatment, 73 and 81 patients from the 3 day and 7 day groups, respectively, were evaluated by intention-to-treat analysis; the microbiological efficacies were 58.9% eradication (43/73), 20.5% persistence (15/73) and 8.2% replaced (6/73), and 66.7% eradication (54/81), 6.2% persistence (5/81) and 7.4% replaced (6/81), respectively (P = 0.048). The clinical efficacies were 76.7% (56/73) and 80.2% (65/81), respectively (P = 0.695). Adverse events due to faropenem were reported in 9.5% of participants (19/200), and the most common adverse event was diarrhoea. CONCLUSIONS The 7 day regimen showed a superior rate of microbiological response. E. coli strains were in general susceptible to faropenem, including fluoroquinolone- and cephalosporin-resistant strains.

Examination of the correlation between the manual and automated serological testing methods for syphilis

We evaluated the correlation between the conventional manual serological testing method for syphilis and a novel automated serological testing method and between six different reagents used in the automated method. Twenty‐six serum samples, which were positive on non‐treponemal manual serological testing, were obtained from 19 patients with early syphilis. The samples were manually analyzed using the non‐treponemal serological test for syphilis kit and automatically analyzed using six different reagents approved by the Ministry of Health, Labor and Welfare in Japan. Statistically significant correlations were observed between most of the reagents used in the automated testing (r = 0.652–0.996, P < 0.001), except for one combination of the reagents. In the simple regression analysis, the slope of the simple regression line (range, 0.014–3.040) and some of the regression coefficients were not equal to 1.0. Therefore, it is recommended that when the automated serological testing method is used to test for syphilis, the same reagent should be consistently selected to evaluate the changes in antibody titers. Statistically significant correlations were also observed between the manual method and all the reagents used in the automated method (r = 0.682–0.811, P < 0.001). In this case, the regression coefficients ranged 0.375–6.270, and the simple regression line intercept ranged −71.926 to 4.184. The regression coefficient and the intercept between the manual method and some of the reagents used in the automated method were not similar to the values described in the documentation attached to the reagents used in this study.

Clinical Efficacy of a Single Two Gram Dose of Azithromycin Extended Release for Male Patients with Urethritis

To clarify the clinical efficacy of a single oral 2 g dose of azithromycin extended-release for heterosexual male patients with urethritis, and the current antimicrobial sensitivity of Neisseria gonorrhoeae to azithromycin, a prospective clinical trial was conducted from 2011–2013. In patients with gonococcal urethritis, the eradication rate was 90.9% (30 of 33). The susceptibility rates of isolated Neisseria gonorrhoeae strains to ceftriaxone, spectinomycin, cefixime and azithromycin were 100%, 100%, 95.3% (41/43) and 37.2% (16/43), respectively. In the patients with nongonococcal urethritis, the eradication rate was 90.0% (45 of 50). The microbiological eradication rates for the pathogens were 90.9% (30/33) for Neisseria gonorrhoeae, 91.5% (43/47) for Chlamydia trachomatis, 71.4% (5/7) for Mycoplasma genitalium, and 100% (13/13) for Ureaplasma urealyticum. The main adverse event was diarrhea and its manifestation rate was 35.2% (32 of 120). The symptom of diarrhea was mostly temporary and resolved spontaneously. The conclusion was that the treatment regimen with a single oral 2 g dose of azithromycin extended-release would be effective for patients with urethritis. However, the antimicrobial susceptibilities of Neisseria gonorrhoeae and Mycoplasma genitalium should be carefully monitored because of possible treatment failure.

Interleukin-1 deficiency in combination with macrophage depletion increases susceptibility to Pseudomonas aeruginosa bacteremia

We evaluated the role of IL‐1 during Pseudomonas aeruginosa bacteremia by intravenously injecting P. aeruginosa strain D4 into IL‐1‐deficient and WT mice. The two strains showed equivalent mortality rates. However, when the mice were pretreated with cyclophosphamide, bacteremia‐induced mortality was significantly greater in the IL‐1‐deficient mice than in the WT mice (P < 0.01). We then investigated the role of neutrophils and macrophages in protecting IL‐1‐deficient mice from bacteremia by administering anti‐Gr‐1 antibody or liposomes containing dichloromethylene diphosphonate, respectively. After P. aeruginosa inoculation survival was significantly lower in the macrophage‐depleted IL‐1‐deficient mice than in the WT mice. In contrast, neutrophil depletion did not have this effect. Compared to the macrophage‐depleted WT mice, the macrophage‐depleted IL‐1‐deficient bacteremic mice had higher bacterial counts in various organs 48 and 72 hr post‐infection. They also had lower TNF‐α, IL‐6, and INF‐γ concentrations in their livers during the early phase of sepsis. Thus, IL‐1 deficiency becomes disadvantageous during P. aeruginosa bacteremia when it is accompanied by immunosuppression, particularly when macrophage functions are seriously impaired.

Effects of nerve growth factor and glucocorticoid on cultured human pheochromocytoma cells

Primary cell cultures of two human pheochromocytomas (PC) that were associated with high serum levels of adrenaline and noradrenaline were developed to study the effects of nerve growth factor (NGF) and dexamethasone on the morphology and function of PC cells in vitro. By phase-contrast microscopy, cultured cells were small and hyperchromatic on the first day of culture; neurite-like processes that extended to other cells developed several days later and were maintained for more than 3 months. NGF (100ng/ml), dexamethasone (10−5M), or NGF + dexamethasone were added to the culture media 2 weeks after the cultured cells had stabilized. Catecholamine concentrations in the medium were maintained at higher levels after addition of NGF, dexamethasone, or NGF + dexamethasone as compared to control cells. In the presence of NGF, extension of neurite-like processes was clearly accelerated, while high levels of dexamethasone inhibited growth of processes. These in vitro studies showed that the addition of NGF or the removal of dexamethasone induces differentiation of adrenal neurons present in pheochromocytomas, suggesting that adrenocortical steroid hormones influence the morphological control of adrenal medullary cells.

A CASE OF A CARCINOSARCOMA OF THE PROSTATE

Carcinosarcoma of the prostate is a rare but aggressive tumor characterized by combination of malignant epithelial and mesenchymal cells. We encountered a case of carcinosarcoma of the prostate. A 78-year-old man with urinary retention was diagnosed with benign prostatic hyperplasia on the basis of the ultrasonography and rectal examination findings, negative result of prostate biopsy. Transurethral resection of the prostate was performed, and the pathological diagnosis was carcinosarcoma of the prostate with squamous cell carcinoma. The patient died of disease 5 months after the diagnosis of carcinosarcoma. A total of 17 cases of carcinosarcoma of the prostate including the present case, have been reported in the Japanese literature to date. Herein we review the 17 cases and discuss the clinical features.