Katsumi Shigemura

Levofloxacin resistant Escherichia coli sepsis following an ultrasound-guided transrectal prostate biopsy: Report of four cases and review of the literature

Abstract:  Fluoroquinolones are the most commonly used prophylactic antimicrobials for ultrasound‐guided transrectal prostate biopsy due to their broad pathogen spectrum, pharmacokinetics, bioavailability and ease of oral administration. However, although Escherichia. coli (E. coli) is the most common pathogen associated with infections after transrectal prostate biopsy, the prevalence of fluoroquinolone resistant strains of E. coli is increasing. Levofloxacin resistant E. coli sepsis occurred in four (0.6%) of 665 patients who received oral levofloxacin prophylaxis and underwent transrectal prostate biopsy from July 2002 to December 2006 in this institute. All patients had obstructions of the lower urinary tract and three of the four had a history of previous use of quinolones. Although two of the four patients developed septic shock, all of the patients were treated with carbapenems immediately and made a complete recovery. Since a case of multiresistant E. coli sepsis and fatal anaerobic sepsis after transrectal prostate biopsy had been reported, intravenous carbapenem is recommended as antimicrobial therapy for sepsis after transrectal prostate biopsy.

Correlation of Overexpression of Efflux Pump Genes with Antibiotic Resistance in Escherichia coli Strains Clinically Isolated from Urinary Tract Infection Patients

ABSTRACT Escherichia coli is one of the most common pathogens in urinary tract infections (UTIs), and antibiotic resistance in E. coli is becoming a serious problem in treating UTI. Efflux system overexpression is reported to contribute to E. coli resistance to several antibiotics. This study investigated the correlation of antibiotic susceptibilities with the overexpression of the efflux pump genes such as marA, yhiU, yhiV, and mdfA and with risk factors for antibiotic resistance in E. coli isolated from UTI patients. We examined the expression level of efflux pump genes using quantitative real-time reverse transcription-PCR (qRT-PCR). We also tested the in vitro susceptibilities to 12 kinds of antibiotics in 64 clinical strains of E. coli isolated from UTI patients. By multivariate analyses we revealed significant relationships between the overexpression of (i) marA and MICs of cefepime (FEP) and nalidixic acid (NAL), (ii) yhiV and MICs of minocycline (MIN), and (iii) mdfA and MICs of sitafloxacin (STX). In our investigation of the efflux pump genes, risk factors such as gender and the previous use of fluoroquinolones correlated with the overexpression of marA, and indwelling catheter use correlated with the overexpression of mdfA. In conclusion, we demonstrated that the increased expression of efflux pump genes such as marA and mdfA can lead to fluoroquinolone resistance in E. coli. These results contribute to our knowledge of the efflux system and raise the possibility of developing new agents, such as efflux pump inhibitors (EPIs), to antibiotic-resistant E. coli.

Etodolac, a Selective Cyclooxygenase-2 Inhibitor, Induces Upregulation of E-Cadherin and Has Antitumor Effect on Human Bladder Cancer Cells In Vitro and In Vivo

OBJECTIVES Cyclooxygenase-2 (COX-2) is highly expressed in several human cancers, including bladder cancer. Thus, a selective COX-2 inhibitor could be useful as an antitumor agent for a range of cancers. In the present study, we investigated the antitumor effect and E-cadherin induction of etodolac, a highly selective COX-2 inhibitor, on human bladder cancer cells in vitro and in vivo. METHODS We examined the cytotoxicity of etodolac against three human bladder cancer cell lines, T24, 5637, and KK47, and performed quantitative reverse transcriptase-polymerase chain reaction to measure the mRNA expression of COX-2, and E-cadherin. RESULTS Etodolac showed significant cytotoxicity only to T24 cells, which expressed the greatest level of COX-2 mRNA and the lowest level of E-cadherin mRNA among the three cell lines. Etodolac also increased the E-cadherin mRNA expression in T24 cells in vitro. We also found that etodolac suppressed tumor growth and induced E-cadherin expression and cell apoptosis in a T24 tumor xenograft mouse model. CONCLUSIONS Etodolac exhibited antitumor activity and induced E-cadherin expression in bladder cancer cells and might be useful for the clinical treatment and prevention of bladder cancer, especially in poorly differentiated bladder cancer with high COX-2 and low E-cadherin expression.

Mucinous tubular and spindle cell carcinoma.

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare, low-grade renal epithelial neoplasm representing a newly established subtype in the World Health Organization (WHO) 2004 classification. Shen et al. reported 12 cases (0.67%) of MTSCC in approximately 1800 cases of renal cell carcinoma (RCC). Here we report a case of MTSCC in a 71-year-old woman.Abdominal dynamic computed tomography (CT) demonstrated that the tumor had well-defined margins (56 ¥ 52 mm), and was not enhanced on the early phase but slightly enhanced on the late phase (Fig. 1a,b). Asymptomatic microscopic hematuria and anemia were detected. Power-doppler ultrasound sonography (US) showed no arterial bloodstream in the tumor. Abdominal magnetic resonance imaging (MRI) demonstrated an isointensity tumor in both T1 and T2-weighted images, and revealed a regional lymph node swelling 7 mm in size. There was no finding of distant metastasis. From these results, this tumor was clinically diagnosed as hypovascular RCC, and staged as clinical T1bN1M0, and retroperitoneoscopic radical left nephrectomy was carried out. The histological findings showed that the tumor was 58 ¥ 57 ¥ 47 mm in size, and was well circumscribed but unencapsulated (Fig. 1c). The tumor was diagnosed as MTSCC of the kidney. The pathological staging was diagnosed as T1bN0M0, INFa, without vascular invasion and lymph node metastasis. The patient recovered uneventfully after surgery. She had no documented recurrence or metastasis at her most recent follow up 7 months after surgery. Most MTSCC tumors were solitary, and were incidentally discovered by US or CT examinations. The radiological finding was generally hypovascular, well-defined tumor. In many cases, radical nephrectomy was carried out under the diagnosis of hypovascular RCC. Distant metastasis and death related to MTSCC has not been reported. The histological staining is characterized by eosinophilic cytoplasm, elongated and anastomosing tubules, myxomatous stroma and lowgrade nuclear cytology with hematoxylin and eosin (H&E) staining. Immunohistochemical staining showed that MTSCC tumor was positive for the markers of epithelial cells and distal nephron, and negative for proximal nephron. Our case corresponded with these findings (Fig. 1d). The histogenetic origin and differentiation of MTSCC remains unclear. Hes et al. reported immunohistochemical and ultrastructural differentiation toward the distal nephron. Some cases with MTSCC show similar histological findings to low-grade collectingduct carcinoma. More recently, the reports showed immunohistochemical overlap with papillary RCC, suggesting differentiation toward the proximal nephron. Indeed , pathologists formerly classified MTSCC as a variant of papillary RCC, sarcomatoid carcinoma or collecting-duct carcinoma before the establishment of the WHO MTSCC definition. Only seven MTSCC cases have been previously reported in Japan to our knowledge. MTSCC has a lower malignant potential than other subtypes of RCC, and therefore it is important to distinguish it from other subtypes of RCC to avoid unnecessary adjuvant immunotherapy with interferon-a, interleukin-2 or others. While the prognosis of MTSCC is generally good , two cases with lymph node metastasis and a few cases with local recurrence were reported. Further investigation will be needed to elucidate the clinical and pathological characteristics of MTSCC with a longer follow-up period. References

In vitro and in vivo inhibitory effect of three Cox-2 inhibitors and epithelial-to-mesenchymal transition in human bladder cancer cell lines

Background:Although the anti-tumour effect of cyclooxygenase-2 (Cox-2) inhibitors in invasive bladder cancer has been confirmed, its mechanisms of action are unclear. Recently, the concept of an epithelial-to-mesenchymal transition (EMT) promoting carcinoma progression has been suggested, and a key feature of the EMT is the downregulation of E-cadherin. In this study, we investigated the effect of Cox-2 inhibitors on reversal EMT and tumour growth inhibition in bladder cancer cells.Methods:We used three Cox-2 inhibitors, etodolac, celecoxib and NS-398 and three human bladder cancer cell lines, T24, 5637 and KK47, in this study. T24 xenograft tumour mouse model was used in the in vivo study.Results:Within the clinical drug concentrations, only etodolac showed the in vitro growth inhibition in T24 not in the other cell lines. Etodolac reduced SNAIL mRNA and vimentin cell surface expression, and induced E-cadherin mRNA and E-cadherin cell surface expression, in T24. Etodolac also most strongly inhibited the cell migration of T24 in vitro and showed the highest tumour growth inhibition in T24 tumour in vivo.Conclusion:Etodolac at clinical doses exhibited induced in vitro and in vivo anti-tumour effects and reversal effect of EMT in T24. These results suggest that etodolac is a good candidate for an anti-tumour or chemopreventive reagent for high-grade bladder cancer.

Complicated urinary tract infection caused by Pseudomonas aeruginosa in a single institution (1999-2003).

Background:  Pseudomonas aeruginosa has been an important uropathogen that causes complicated urinary tract infection. We investigated the clinical characteristics of complicated urinary tract infection caused by Pseudomonas aeruginosa in a single institution.

Comparison of the Transperitoneal and Retroperitoneal Approach in Robot-Assisted Partial Nephrectomy in an Initial Case Series in Japan

PURPOSE To compare the results from the transperitoneal and retroperitoneal approaches in our initial case series of robot-assisted partial nephrectomy (RAPN) in terms of surgical time, renal artery clamping time, postoperative renal function, adverse events, and surgical margin status. PATIENTS AND METHODS The initial 26 consecutive RAPNs performed for solid renal tumors in our hospital were categorized by the approach used, transperitoneal or retroperitoneal, and compared for body mass index, tumor size, R.E.N.A.L. nephrometry score, PADUA score, tumor location, surgical time, renal artery clamping time, renal function change after surgery, operative blood loss, surgical margin status, and adverse events (AEs). RESULTS The median tumor size was 25 mm (range 15-50). A transperitoneal approach was used in 16 patients and a retroperitoneal approach was used in 10 patients. There was no significant difference in renal tumor and patient characteristics between the two groups except tumor location (anterior tumor was significantly more in the transperitoneal approach and posterior tumor was significantly more in retroperitoneal approach (P=0.0144 and P=0.0100, respectively)). Operative time (239 ± 63.0 minutes in the transperitoneal group vs. 193 ± 40.6 minutes in the retroperitoneal group), warm ischemic time (24.3 ± 9.07 minutes in the transperitoneal group vs. 24.7 ± 8.35 minutes in the retroperitoneal group) and AEs (1/16 in the transperitoneal group vs. 1/10 in the retroperitoneal group; both cases were Clavien-Dindo grade I) did not show any significant difference between the two approaches (P=0.0792, 0.5485, and 0.7270, respectively). CONCLUSIONS The retroperitoneal approach in RAPN appears to be a safe and technically feasible minimally invasive option for nephron-sparing surgery, based on our initial case series, and showed equivalent outcomes to those of the transperitoneal approach even though it was an initial robotic renal surgery series. Future studies, including a larger number of cases, are planned to draw more definitive conclusions.

Clinical investigation of isolated bacteria from urinary tracts of hospitalized patients and their susceptibilities to antibiotics

Complicated urinary tract infections (UTIs) are often difficult to treat, partly because of the existence of isolated antibiotic-resistant strains. Even though the definition of UTI is determined by the quantity of cultured bacteria, it has been unclear if the quantity of cultured UTI bacteria affects their susceptibility to antimicrobial agents. Also, the gram stain is generally performed to assume the causative bacteria and their quantity before culture results can be obtained; therefore, we could start to use effective antibiotics if the relationship between bacterial quantity and resistance to antimicrobial agents were clear. We studied patients diagnosed as having complicated UTIs at the Urological Department in Kobe University Hospital between June 2002 and March 2003 and analyzed the relationships between the quantity of cultured bacteria and their antimicrobial MICs for antibiotics. The most commonly isolated bacteria were Serratia marcescens, Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli, Staphylococcus epidermidis, Stenotrophomonas maltophilia, and methicillin-resistant Staphylococcus aureus. There was no significant correlation between the quantity of cultured bacteria and antimicrobial MICs in all the bacteria and antibiotics that we tested, suggesting that resistant phenotype, but not inoculum of the organism, did determine resistance to antibiotics. In conclusion, our investigation suggested the total number of isolated bacteria in urine culture did not determine the MICs and that inoculum of the bacteria might be important for this determination.

Rapid detection and differentiation of Gram-negative and Gram-positive pathogenic bacteria in urine using TaqMan probe

Urinary tract infection has been shown to be quite complicated and often difficult to diagnose and treat. For appropriate diagnosis, it is very important to find the correct Gram stain classification as soon as possible, especially in severe cases where there is a possibility of severe sepsis developing. In order to solve this problem, we developed a new method to detect a Gram stain of bacteria obtained from 1 ml of urine from urinary tract infection patients using a consensus real-time PCR protocol with a TaqMan probe that allows detection of spiked bacterial 16S DNA from urine. We extracted DNA of 55 urine samples obtained from patients with complicated urinary tract infection and at the same time performed urine culture testing. After DNA extraction, they were subjected to real-time PCR using a TaqMan discrimination system. Sixteen kinds of bacteria were cultured from the urine culture testing. Of these bacteria, eight were classified as Gram-positive bacteria and the other eight were classified as Gram-negative bacteria. Of the 55 samples, the TaqMan technique result showed 27 samples that were classified as Gram-negative bacteria; 11 samples that were Gram-positive, 10 that included both Gram-negative and -positive bacteria, and 7 that showed no amplification. The classifications of all samples corresponded exactly to those determined by urine culture testing. The present genotyping method of real-time PCR using a TaqMan discrimination system could be applied to the rapid detection of Gram-positive or -negative bacteria in urine of urinary tract infection patients. This assay can differentiate those species tested, but whether the presence of other (untested) bacteria could lead to misinterpretation is unknown. For further investigation, it is important to test other (untested) bacteria in the near future.

Quantitative detection of Escherichia coli from urine of patients with bacteriuria by real-time PCR.

AbstractIntroduction: Compared with the classical urine culture method, PCR is more rapid, and can detect smaller numbers of bacteria, however it is inferior for quantification. Because of the lack of quantification in routine PCR, the meaning of a positive PCR test result has not been validated for all infections. We report on the development of a novel quantitative detection system for the urinary tract infection (UTI) Escherichia coli using real-time PCR. Patients: We enrolled 200 patients with suspected bacteriuria. Methods: The gene encoding the universal stress protein (uspA) was found to be highly specific for E. coli. We quantified the copy numbers of E. coli in the urine of patients with UTI by using a real-time PCR assay (the TaqMan® system) targeting uspA genes in genomic DNAs isolated from urine samples (n = 200). To evaluate the feasibility of this method, the results were compared with those of a standard urine culture. Results: The incidence of positive urine cultures was 75% (150 of 200), and various doses of E. coli were detected in 84 of 150 specimens. The real-time PCR method also detected 84 cases of urinary infections of E. coli in the same specimens. Furthermore, the result of the quantification of E. coli using real-time PCR strongly correlated (r2 = 0.925) with the result of urine culture. Conclusion: Our results suggest that using quantitative-PCR means a faster and simpler diagnosis of E. coli urinary infection can be made compared with the traditional urine culture method.