Fourth national Japanese antimicrobial susceptibility pattern surveillance program: Bacterial isolates from patients with complicated urinary tract infections

INTRODUCTION

Antimicrobial susceptibility patterns of bacterial pathogens isolated from patients with complicated urinary tract infections were analyzed using the national surveillance data, comprising 793 bacterial strains from eight clinically relevant species.

MATERIALS AND METHODS

Data were collected for the fourth national surveillance project from July 2020 to December 2021 by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Disease, and the Japanese Society of Clinical Microbiology. Surveillance was supervised with the cooperation of 43 medical institutions throughout Japan.

RESULTS

Fluoroquinolone required a minimum inhibitory concentration (MIC) of 2-64 mg/L to inhibit the 330 tested Escherichia coli strains. The proportion of levofloxacin-resistant E. coli strains increased from 28.6% in 2008 to 29.6% in 2011, 38.5% in 2015, and 44.5% in 2021. The proportion of levofloxacin-resistant strains of Pseudomonas aeruginosa also increased from previous survey results, showing a continuing downward trend. Conversely, the proportion of levofloxacin-resistant strains of Enterococcus faecalis decreased relative to previous reports. Neither multidrug-resistant P. aeruginosa nor carbapenem-resistant Enterobacteriaceae were detected. For methicillin-resistant Staphylococcus aureus (MRSA), the proportion of vancomycin-susceptible strains (MIC of 2 μg/mL) decreased from 14.7% to 7.7%.

DISCUSSION

Bacterial strains that produced extended-spectrum β-lactamase included E. coli (82/330 strains, 24.8%), Klebsiella pneumoniae (11/68 strains, 16.2%), and Proteus mirabilis (4/26 strains, 15.4%). As compared to previous surveillance reports, these strains showed an increase in proportion over the years.

Third nationwide surveillance of bacterial pathogens in patients with acute uncomplicated cystitis conducted by the Japanese surveillance committee during 2020 and 2021: Antimicrobial susceptibility of Escherichia coli, Klebsiella pneumoniae, and Staphylococcus saprophyticus

The Japanese surveillance committee conducted a third nationwide surveillance of antimicrobial susceptibility of acute uncomplicated cystitis at 55 facilities throughout Japan between April 2020 and September 2021. In this surveillance, we investigated the susceptibility of Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae), and Staphylococcus saprophyticus (S. saprophyticus) for various antimicrobial agents by isolating and culturing bacteria from urine samples. In total, 823 strains were isolated from 848 patients and 569 strains of target bacteria, including E. coli (n = 529, 92.9 %), K. pneumoniae (n = 28, 4.9 %), and S. saprophyticus (n = 12, 2.2 %) were isolated. The minimum inhibitory concentrations of 18 antibacterial agents were determined according to the Clinical and Laboratory Standards Institute manual. In premenopausal patients, there were 31 (10.5 %) and 20 (6.8 %) fluoroquinolone (FQ)-resistant E. coli and extended-spectrum β-lactamase (ESBL)-producing E. coli, respectively. On the other hand, in postmenopausal patients, there were 75 (32.1 %) and 36 (15.4 %) FQ-resistant E. coli and ESBL-producing E. coli, respectively. The rate of FQ-resistant E. coli and ESBL-producing E. coli in post-menopausal women was higher than that for our previous nationwide surveillance (20.7 % and 32.1 %: p = 0.0004, 10.0 % and 15.4 %; p = 0.0259). For pre-menopausal women, there was no significant difference in the rate of FQ-resistant E. coli and ESBL-producing E. coli between this and previous reports, but the frequency of FQ-resistant E. coli and ESBL-producing E. coli exhibited a gradual increase. For appropriate antimicrobial agent selection and usage, it is essential for clinicians to be aware of the high rate of these antimicrobial-resistant bacteria in acute uncomplicated cystitis in Japan.

The third nationwide surveillance of antimicrobial susceptibility against Neisseria gonorrhoeae from male urethritis in Japan, 2016-2017

Neisseria gonorrhoeae is one of the important pathogens of sexually transmitted infections. N. gonorrhoeae is rapidly becoming antimicrobial resistant, and there are few drugs that are effective in the initial treatment of gonorrhea. To understand the trends of antimicrobial susceptibility of N. gonorrhoeae, the Surveillance Committee of the Japanese Society of Infectious Diseases, the Japanese Society for Chemotherapy, and the Japanese Society of Clinical Microbiology conducted the third nationwide antimicrobial susceptibility surveillance of N. gonorrhoeae isolated from male urethritis. The specimens were collected from male patients with urethritis at 30 facilities from May 2016 to July 2017. From the 159 specimens collected, 87 N. gonorrhoeae strains were isolated, and 85 were tested for susceptibility to 21 antimicrobial agents. All strains were non-susceptible to penicillin G. Seven strains (8.2%) were β-lactamase-producing strains. The rates of susceptibility to cefixime and cefpodoxime were 96.5% and 52.9%, respectively. Three strains were non-susceptible with a minimum inhibitory concentration (MIC) of 0.5 mg/L for cefixime. None of the strains were resistant to ceftriaxone or spectinomycin. The susceptibility rate for ciprofloxacin was 23.5% (20 strains), and no strains showed intermediate susceptibility. The susceptibility rate against azithromycin was 81.2%, with one strain isolated with a MIC of 8 mg/L against azithromycin. The results of this surveillance indicate that ceftriaxone and spectinomycin, which are currently recommended for gonococcal infections in Japan, appear to be effective. It will be necessary to further expand the scale of the next surveillance to understand the current status of drug-resistant N. gonorrhoeae in Japan.

Differential impact of proton pump inhibitor on survival outcomes of patients with advanced urothelial carcinoma treated with chemotherapy versus pembrolizumab

OBJECTIVES

We clarified the effect of concomitant proton pump inhibitor use on oncological outcomes in patients with advanced urothelial carcinoma treated either with chemotherapy or immune checkpoint inhibitor.

METHODS

We retrospectively reviewed patients with advanced urothelial carcinoma who received paclitaxel-gemcitabine therapy or pembrolizumab after platinum-based chemotherapy. The patients were divided into four groups based on the treatment regimen and the concomitant use of proton pump inhibitor. We compared survival outcomes between the groups and determined which factors predicted overall survival.

RESULTS

Among the 60 and 75 patients treated with paclitaxel-gemcitabine and pembrolizumab, 15 and 29 used a concomitant proton pump inhibitor. Progression-free and overall survival was significantly shorter in patients who were administered pembrolizumab with concomitant proton pump inhibitor compared to those without. The use of a concomitant proton pump inhibitor had no effect on survival outcomes in patients who received paclitaxel-gemcitabine therapy. Furthermore, progression-free and overall survival were significantly shorter in patients treated with paclitaxel-gemcitabine therapy compared to those treated with pembrolizumab among patients without concomitant proton pump inhibitor. In contrast, there was no difference in survival outcomes between the two regimens among patients with concomitant proton pump inhibitor. Concomitant proton pump inhibitor use was associated with poor overall survival only in patients treated with pembrolizumab.

CONCLUSION

The use of a concomitant proton pump inhibitor use had no impact on oncological outcomes in patients with advanced urothelial carcinoma treated with paclitaxel-gemcitabine therapy, different from those treated with pembrolizumab.

Association Between Body Mass Index and Outcomes in Patients With Urothelial Carcinoma Treated With Pembrolizumab

BACKGROUND/AIM

We aimed to clarify the association between body mass index (BMI) and clinical outcomes of pembrolizumab treatment for advanced urothelial cancer (UC).

PATIENTS AND METHODS

We retrospectively reviewed the records of patients with advanced UC who received pembrolizumab after chemotherapy between March 2018 and December 2021. Patients were divided according to BMI into the non-overweight group (BMI <25 kg/m²) and the overweight group (BMI ≥25 kg/m²). We compared the two groups' tumour response, survival rates, and incidence of immune-related adverse events (irAEs) and investigated the factors predicting survival.

RESULTS

Of 84 eligible patients, 63 (75%) and 21 (25%) were in the non-overweight and overweight groups, respectively. Although the objective response rate was higher in the overweight group (55%) than that in the non-overweight group (29%), the difference was not significant. Progression-free survival (PFS) was significantly longer in the overweight group (median 15.2 months) than that in the non-overweight group (median 4.8 months; p=0.01). Overall survival was also longer in the overweight group (median 36.1 months) compared to that in the non-overweight group (13.4 months), but the difference was not significant (p=0.11). Multivariable analysis showed that overweight was significantly associated with favourable PFS. Any and severe (grade 3) irAEs were observed in 15 (24%) and 5 (7.9%) patients in the non-overweight group, respectively, and in 8 (38%) and 2 (9.5%) patients in the overweight group, respectively, but the differences were not significant.

CONCLUSION

BMI was associated with oncological outcomes in patients with advanced UC who received pembrolizumab but not with the development of irAEs.

Detection of Neisseria gonorrhoeae or Chlamydia trachomatis from oral wash specimens using the Abbott RealTime CT/NG assay and the Cobas 4800 CT/NG assay: A prospective study

INTRODUCTION

Isolating oropharyngeal Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) from oral wash specimens (OWSs) is uncommon. Therefore, we evaluated the performance of the Abbott RealTime CT/NG assay and the Cobas 4800 CT/NG assay in detecting NG and CT in OWSs.

METHODS

This multicenter prospective study included 457 patients from 14 medical facilities suspected of having untreated male urethritis or female cervicitis from November 2014 to December 2015. OWSs were collected and tested using the Abbott and Cobas assays. Finally, the discordant results were confirmed using the APTIMA Combo 2 transcription-mediated amplification assay and retested using each assay.

RESULTS

The sensitivity and specificity of the Abbott assay were 100% and 97.2% for NG and 87.5% and 100% for CT, respectively, and of the Cobas assay were 100% and 98.8% for NG and 93.8% and 99.8% for CT, respectively. Both assays had high negative but low positive predictive values for oropharyngeal NG (Abbott assay: 65.7%, Cobas assay: 82.1%). Based on the definition of "true positive," the prevalence of oropharyngeal NG and CT were 5.0% and 3.5%, respectively.

CONCLUSIONS

The Abbott and Cobas assays using OWSs had high sensitivity and specificity, which can help diagnose oropharyngeal NG and CT. We consider that if a positive result is obtained, the patient should be treated because the negative predictive values were high. However, limited data are available on oropharyngeal NG and CT detection, and further studies are needed to clarify the role of oropharyngeal sexually transmitted infections.

Nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis from male urethritis in Japan: Comparison with the first surveillance report

The Urogenital Sub-committee and the Surveillance Committee of the Japanese Society of Chemotherapy, The Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology conducted the second nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis. In this second surveillance study, clinical urethral discharge specimens were collected from patients with urethritis in 26 hospitals and clinics from May 2016 to July 2017. Based on serial cultures, the minimum inhibitory concentration (MIC) could be determined for 41 isolates; the MICs (MIC₉₀) of ciprofloxacin, levofloxacin, tosufloxacin, sitafloxacin, doxycycline, minocycline, erythromycin, clarithromycin, azithromycin and solithromycin were 2 μg/ml (2 μg/ml), 1 μg/ml (0.5 μg/ml), 0.25 μg/ml (0.25 μg/ml), 0.125 μg/ml (0.063 μg/ml), 0.125 μg/ml (0.125 μg/ml), 0.25 μg/ml (0.25 μg/ml), 0.031 μg/ml (0.031 μg/ml), 0.25 μg/ml (0.125 μg/ml), and 0.016 μg/ml (0.008 μg/ml), respectively. In summary, this surveillance project did not identify any strains resistant to fluoroquinolone, tetracycline, or macrolide agents in Japan. In addition, the MIC of solithromycin was favorable and lower than that of other antimicrobial agents. However, the MIC of azithromycin had a slightly higher value than that reported in the first surveillance report, though this might be within the acceptable margin of error. Therefore, the susceptibility of azithromycin, especially, should be monitored henceforth.

Guidelines for Infection Control in the Urological Field, including Urinary Tract Management (revised second edition)

The Committee for the Development of Guidelines for Infection Control in the Urological Field, including Urinary Tract Management of the Japanese Urological Association, together with its systematic review team and external reviewers, have prepared a set of practice guidelines, an abridged version of which is published herein. These guidelines cover the following topics: (i) foundations of infection control, standard precautions, route-specific precautions, and occupational infection control (including vaccines); (ii) the relationship between urologists and infection control; (iii) infection control in urological wards and outpatient clinics; (iv) response to hepatitis B virus reactivation; (v) infection control in urological procedures and examinations; (vi) prevention of infections occurring in conjunction with medical procedures and examinations; (vii) responses to urinary tract tuberculosis and bacillus Calmette-Guérin; (viii) aseptic handling, cleaning, disinfection, and sterilization of urinary tract endoscopes (principles of endoscope manipulation, endoscope lumen cleaning, and disinfection); (ix) infection control in the operating room (principles of hand washing, preoperative rubbing methods, etc.); (x) prevention of needlestick and blood/bodily fluid exposure and response to accidental exposure; (xi) urinary catheter-associated urinary tract infection and purple urinary bag syndrome; and (xii) urinary catheter-associated urinary tract infections in conjunction with home care. In addressing these topics, the relevant medical literature was searched to the extent possible, and content was prepared for the purpose of providing useful information for clinical practice.

UAA-AAUS guideline for M. genitalium and non-chlamydial non-gonococcal urethritis

Non-chlamydial non-gonococcal urethritis (NCNGU) is defined as urethritis with neither Neisseria gonorrhoeae nor Chlamydia trachomatis. Possible causative agents of NCNGU include Mycoplasma genitalium, Ureaplasma urealyticum, Ureaplasma parvum, Mycoplasma hominis, Trichomonas vaginalis, and so on. Among these microorganisms, the pathogenicity of M. genitalium and T. vaginalis to the male urethra has been confirmed so far. The Asian Association of Urinary Tract Infection and Sexually Transmitted Infection (AAUS) belonging to the Urological Association of Asia (UAA) had developed the guidelines regarding NCNGU and the present guidelines were updated from previous edition. Relevant references were meticulously reviewed again and latest studies were collected. In addition to the levels of evidence, the recommendation grades were defined using the modified GRADE methodology. Herein, we present the new edition of the UAA-AAUS guidelines for M. genitalium and non-chlamydial non-gonococcal urethritis.

Nationwide surveillance of bacterial pathogens isolated from patients with acute uncomplicated cystitis in 2018: Conducted by the Japanese Research Group for Urinary Tract Infections (JRGU)

INTRODUCTION

The aim of this study was to monitor the development of drug-resistant bacteria isolated from acute uncomplicated cystitis (AUC) and to evaluate methodology of the survey conducted by collecting only clinical data.

METHODS

We enrolled female patients at least 16 years of age diagnosed with AUC in 2018. Patient information including age, menopausal status, and results of bacteriological examination were collected and analyzed regardless of bacterial identification, antimicrobial susceptibility testing or extended-spectrum β-lactamase (ESBL) detection method.

RESULTS

A total of 847 eligible cases were collected. Escherichia coli (E. coli) was the most frequently isolated bacterial species at about 70%, with proportions of fluoroquinolone-resistant E. coli (QREC) and ESBL-producing E. coli isolates at 15.6% and 9.5% of all E. coli isolates, respectively. The proportion of Staphylococcus saprophyticus (S. saprophyticus) was significantly higher in premenopausal women. Regarding the drug susceptibility of E. coli, isolates from Eastern Japan had significantly higher susceptibility to cefazolin, cefotiam and cefpodoxime and lower susceptibility to levofloxacin in postmenopausal women. ESBL-producing E. coli isolates had a high susceptibility to tazobactam-piperacillin, cefmetazole, carbapenems, aminoglycosides, and fosfomycin. In S. saprophyticus, the susceptibility to β-lactams including carbapenems was 40-60%.

CONCLUSIONS

The proportions of QREC and ESBL-producing E. coli were increasing trends and lower susceptibility to LVFX in postmenopausal women was observed. Such surveillance, consisting of the collecting only clinical data, could be conducted easily and inexpensively. It is expected to be continuously performed as an alternative survey to conventional one collecting bacterial strains.

Sensitivity of a transcription-mediated amplification method (Aptima Mycoplasma genitalium assay) to detect M. genitalium in vitro

INTRODUCTION

Mycoplasma genitalium is a known causative pathogen for some sexually transmitted infections. Nucleic acid amplification tests are a recommended method for detecting M. genitalium. A transcription-mediated amplification (TMA) nucleic acid amplification test to detect M. genitalium, the Aptima Mycoplasma genitalium assay was approved by the Food and Drug Administration in the United States and has been used in other countries. The purpose of this study is to determine the sensitivity of TMA test as the detection limit for 20 strains.

METHOD

The sensitivity of the TMA test was re-examined using 20 strains in vitro and the detection limit was estimated by comparison with the MgPa quantitative real-time PCR (qPCR) method. The M. genitalium strains used were isolated from Denmark, Norway, Sweden, France and Japan, and included macrolide or fluoroquinolone resistance. Stock strains were used at several dilutions, with each dilution of each strain examined using both TMA test and qPCR methods.

RESULT AND CONCLUSION

Estimated DNA loads of M. genitalium as the detection limit were 0.03-0.87 genome equivalents/mL. Sensitivity for TMA test was almost 100-fold higher than for the qPCR method.

Risk Factors for Puncture Site Complications Using the Angio-Seal Closure Device in Endovascular Therapy: A Single-center Analysis

OBJECTIVE

To retrospectively analyze the complication rates and risk factors associated with the use of the Angio-Seal vascular closure device during neuroendovascular therapy.

METHODS

In this study, we enrolled 283 patients who underwent Angio-Seal hemostasis between December 2005 and June 2019 at our institute. We retrospectively analyzed the major and minor complication rates and risk factors between the complication and no-complication groups using the medical charts of patients for whom the device was used.

RESULTS

Of the 283 patients, 5 had major complications (1.8%) and 18 had minor complications (6.3%). There were no significant differences between the complication (n = 23) and no-complication (n = 260) groups regarding the baseline characteristics or operation procedures. Among the major complications, superficial femoral artery puncture, 8Fr device, Angio-Seal Evolution, post-carotid artery stenting, dual antiplatelet therapy, and delirium were considered risk factors.

CONCLUSION

The Angio-Seal is a safe and useful hemostatic device. However, puncture site complications need to be considered when the device is used for contraindicated patients or for those with delirium who cannot rest following the procedure.

Efficacy of Prophylactic Antimicrobial Administration of Tazobactam/Piperacillin for Radical Cystectomy with Urinary Diversion: A Multicenter Study

OBJECTIVES

The purpose of this study was to investigate the association between prophylactic antibiotic administration (PAA) and postoperative infection after radical cystectomy with urinary diversion in patients with invasive bladder cancer.

METHODS

Forty-nine consecutive cases were analyzed prospectively. Postoperative infections were categorized as surgical site infection (SSI) and remote infection (RI). We used the antibiotics tazobactam/piperacillin (TAZ/PIPC) as PAA (48 h).

RESULTS

A total of 18 (36.7%) patients had postoperative infections, 4/18 (22.2%) patients had wound infections, and 12/18 (66.7%) patients had RI. In the risk factor study for SSI and RI occurrences, we found that the surgical time was significantly shorter in the non-infection group (p = 0.031). Taken together, these results suggest that TAZ/PIPC with shorter PAA duration (48 h) might lead to a lower rate of postoperative infections.

CONCLUSIONS

Our data showed that PAA with TAZ/PIPC with a shorter duration PAA (48 h) might be recommended for RC with urinary diversion. We found that the surgical time was significantly shorter in the non-infection group. A prospective study based on our data is desirable to establish or revise PAA strategy for prophylactic medication to prevent postoperative infection after RC with urinary diversion.

Mutations in ParC and GyrA of moxifloxacin-resistant and susceptible Mycoplasma genitalium strains

Macrolide or fluoroquinolone-resistant Mycoplasma genitalium is spreading worldwide. We aimed to determine the influence of single nucleotide polymorphisms (SNPs) in the quinolone resistance determining regions (QRDR) of parC and gyrA in cultured M. genitalium strains. In addition, we examined the prevalence of macrolide- and fluoroquinolone resistance mediating mutations in specimens collected from Japanese male patients with urethritis in two time-periods between 2005–2009 and 2010–2017, respectively, by sequencing the QRDR of parC and gyrA and domain V of the 23S rRNA gene. The minimum inhibitory concentrations (MIC) of moxifloxacin, sitafloxacin, ciprofloxacin, levofloxacin, doxycycline, minocycline, azithromycin and clarithromycin were determined in 23 M. genitalium strains. Three cultured strains had elevated MICs for moxifloxacin at 16, 4 and 2 mg/L and had SNPs with the amino-acid change Ser83→Ile in ParC (p<0.001) and 3 kinds of SNPs with amino-acid changes Asp99→Asn, Gly93→Cys and Met95→Ile in GyrA, respectively. Among a total of 148 M. genitalium positive urine specimens, the prevalence of A2058G and A2059G SNPs in the 23S rRNA gene and any SNPs in ParC increased from 4.8% and 22.6% in 2005–2009 to 42.2% and 53.1% in 2010–2017, respectively. If M. genitalium is considered multi-drug resistant in clinical specimens carrying SNPs in the 23S rRNA gene and Ser83→Ile in ParC, the prevalence of multi-drug resistance is 12.5% in 2010–2017 in Japan. In conclusion, the SNP resulting in Ser83→Ile in ParC is closely related to moxifloxacin resistance even though other factors may also affect treatment outcomes by moxifloxacin. The prevalence of circulating multi-drug resistant M. genitalium strains with macrolide- and fluoroquinolone-resistance is dramatically increasing in Japan.

Summary of the UAA-AAUS guidelines for urinary tract infections

Urinary tract infections, genital tract infections and sexually transmitted infections are the most prevalent infectious diseases, and the establishment of locally optimized guidelines is critical to provide appropriate treatment. The Urological Association of Asia has planned to develop the Asian guidelines for all urological fields, and the present urinary tract infections, genital tract infections and sexually transmitted infections guideline was the second project of the Urological Association of Asia guideline development, which was carried out by the Asian Association of Urinary Tract Infection and Sexually Transmitted Infection. The members have meticulously reviewed relevant references, retrieved via the PubMed and MEDLINE databases, published between 2009 through 2015. The information identified through the literature review of other resources was supplemented by the author. Levels of evidence and grades of recommendation for each management were made according to the relevant strategy. If the judgment was made on the basis of insufficient or inadequate evidence, the grade of recommendation was determined on the basis of committee discussions and resultant consensus statements. Here, we present a short English version of the original guideline, and overview its key clinical issues.

In vitro activity and time-kill curve analysis of sitafloxacin against a global panel of antimicrobial-resistant and multidrug-resistant Neisseria gonorrhoeae isolates

Treatment of gonorrhoea is a challenge worldwide because of emergence of resistance in N. gonorrhoeae to all therapeutic antimicrobials available and novel antimicrobials are imperative. The newer-generation fluoroquinolone sitafloxacin, mostly used for respiratory tract infections in Japan, can have a high in vitro activity against gonococci. However, only a limited number of recent antimicrobial-resistant isolates from Japan have been examined. We investigated the sitafloxacin activity against a global gonococcal panel (250 isolates cultured in 1991-2013), including multidrug-resistant geographically, temporally and genetically diverse isolates, and performed time-kill curve analysis for sitafloxacin. The susceptibility to sitafloxacin (agar dilution) and seven additional therapeutic antimicrobials (Etest) was determined. Sitafloxacin was rapidly bactericidal, and the MIC range, MIC₅₀ and MIC₉₀ was ≤0.001-1, 0.125 and 0.25 mg/L, respectively. There was a high correlation between the MICs of sitafloxacin and ciprofloxacin; however, the MIC₅₀ and MIC₉₀ of sitafloxacin were 6-fold and >6-fold lower, respectively. Sitafloxacin might be an option for particularly dual antimicrobial therapy of gonorrhoea and for cases with ceftriaxone resistance or allergy. However, further in vitro and particularly in vivo evaluations of potential resistance, pharmacokinetics/pharmacodynamics and ideal dosing for gonorrhoea, as well as performance of randomized controlled clinical, trials are crucial.

In Vitro Activity of Sitafloxacin and Additional Newer Generation Fluoroquinolones Against Ciprofloxacin-Resistant Neisseria gonorrhoeae Isolates

Emergence of antimicrobial resistance in Neisseria gonorrhoeae is a major public health concern globally, and new antimicrobials for treatment of gonorrhea are imperative. In this study, the in vitro activity of sitafloxacin, a fluoroquinolone mainly used for respiratory tract or urogenital infections in Japan, and additional newer generation fluoroquinolones were determined against ciprofloxacin-resistant N. gonorrhoeae isolates. Minimum inhibitory concentrations (MICs) of ciprofloxacin, levofloxacin, moxifloxacin, sitafloxacin, pazufloxacin, and tosufloxacin against 47 N. gonorrhoeae isolates cultured in 2009 in Japan were determined by agar dilution method. The quinolone resistance-determining region (QRDR) of gyrA and parC was sequenced. The in vitro potency of sitafloxacin was substantially higher compared with all other tested fluoroquinolones. The MICs of sitafloxacin ranged from 0.03 to 0.5 mg/L for 35 ciprofloxacin-resistant N. gonorrhoeae isolates (ciprofloxacin MICs from 2 to 32 mg/L). No identified mutations in GyrA and ParC QRDR resulted in higher sitafloxacin MIC than 0.5 mg/L. Sitafloxacin had a high activity against N. gonorrhoeae isolates, including strains with mutations in DNA gyrase and topoisomerase IV, resulting in high-level resistance to ciprofloxacin and all other newer generation fluoroquinolones examined. However, it was still to a lower extent affected by GyrA and ParC QRDR mutations resulting in sitafloxacin MICs of up to 0.5 mg/L. This indicates that sitafloxacin should not be considered for empirical first-line monotherapy of gonorrhea. However, sitafloxacin could be valuable in a dual antimicrobial therapy and for cases with ceftriaxone resistance or allergy.

An Effective Case for Chyluria by Retroperitoneoscopic Lymphatic Disconnection

Background: Chyluria is a rare disease in Japan. Lymphatic disconnection is the most effective treatment for patients with Chyluria, and laparoscopic approach is performed as a minimally invasive technique.

Case Presentation: We present a case of a 40-year-old man who referred to our hospital because of recurrence of chyluria. Chyluria had continued for 20 years, and the patient had received retrograde instillations of silver nitrate three times. The patient underwent retroperitoneoscopic nephrolympholysis, and the chyluria disappeared immediately. One year after surgery, chyluria has not recurred.

Conclusion: We treated a patient with chyluria by performing retroperitoneoscopic lymphatic disconnection and this procedure is less invasive and easy to perform.

Nationwide surveillance of the antimicrobial susceptibility of Chlamydia trachomatis from male urethritis in Japan

Genital chlamydial infection is a principal sexually transmitted infection worldwide. Chlamydia trachomatis can cause male urethritis, acute epididymitis, cervicitis, and pelvic inflammatory disease as sexually transmitted infections. Fortunately, homotypic resistant C. trachomatis strains have not been isolated to date; however, several studies have reported the isolation of heterotypic resistant strains from patients. In this surveillance study, clinical urethral discharge specimens were collected from patients with urethritis in 51 hospitals and clinics in 2009 and 38 in 2012. Based on serial cultures, the minimum inhibitory concentration (MIC) could be determined for 19 isolates in 2009 and 39 in 2012. In 2009 and 2012, the MICs (MIC90) of ciprofloxacin, levofloxacin, tosufloxacin, sitafloxacin, doxycycline, minocycline, erythromycin, clarithromycin, and azithromycin were 2 μg/ml and 1 μg/ml, 0.5 μg/ml and 0.5 μg/ml, 0.125 μg/ml and 0.125 μg/ml, 0.063 μg/ml and 0.063 μg/ml, 0.125 μg/ml and 0.125 μg/ml, 0.125 μg/ml and 0.125 μg/ml, 0.016 μg/ml and 0.016 μg/ml, and 0.063 μg/ml and 0.063 μg/ml, respectively. In summary, this surveillance project did not identify any resistant strain against fluoroquinolone, tetracycline, or macrolide agents in Japan.

Protective Effect of Carrageenan against Murine Cytomegalovirus Infection in Mice

The protective effect of iota-carrageenan (CAR) was evaluated against murine cytomegalovirus (MCMV) infection in mice. Female ICR mice were challenged intraperitoneally (i.p.) with 3 LD50 of salivary gland-passaged MCMV. More than 0.5 mg of CAR showed a protective effect on mice only when CAR was administered i.p. and then MCMV was inoculated i.p. The protective effect of CAR was evidenced by an increase in plaque-forming unit per LD50 and a decrease in the titre of infectious viruses in the target organs. Neither a virucidal nor a virustatic effect on MCMV was evidenced for CAR. The protective effect of CAR seemed to be host-mediated.

Pretreatment of mice with CAR augmented natural killer (NK) activity of the spleen cells without elevating the serum interferon level. However, administration of anti-asialo GM1 antibody did not nullify the inhibitory effect of CAR on virus replication in the target organs. MCMV infection induced leukopenia including neutropenia and lymphopenia in saline-treated mice. Pretreatment with CAR protected mice from those signs, except for slight lymphopenia. Administration of cyclophosphamide induced severe leukopenia including neutropenia and lymphopenia even in CAR-treated mice. Under such conditions, the protective effect of CAR against MCMV infection was abrogated by cyclophosphamide. Thus, the protective effect of CAR seems to be non-NK-mediated.