Naoko Fujihara

Clinical factors associated with fluconazole resistance and short-term survival in patients with Candida bloodstream infection

In a 1-year national surveillance program of Candida bloodstream infections in Japan, clinical factors predicting fluconazole resistance and survival of the patients were analyzed. Blood isolates and complete clinical histories were obtained from 326 patients. Fluconazole-resistant isolates were found in 15 (4.6%) of the cases. Univariate analysis of the demographic and clinical factors associated with fluconazole resistance revealed that age, hematologic malignancy, neutropenia, and immunosuppression were of statistical significance. A multiple logistic regression model showed that only hematologic malignancy as the underlying disease (odds ratio, 6.6; 95% confidence interval, 1.6–26.9; P=0.009) was independently associated with resistance. In 242 cases in which data regarding management and prognosis were available, the 30-day survival rate was 68.4%. In the univariate analysis of factors predicting survival, a significant association was found for Candida species, age of the patient, neutropenia, recent abdominal surgery, removal of the central venous catheter, and use of appropriate antifungal therapy. In the multivariate analysis, removal of the central venous catheter (odds ratio, 6.0; 95% confidence interval, 2.2–16.1; P<0.001) and the use of appropriate therapy (odds ratio, 2.1; 95% confidence interval, 1.1–4.1; P=0.03) were independent factors significantly associated with survival after the diagnosis of Candida bloodstream infection.

Surgical site infection due to Mycobacterium peregrinum: a case report and literature review

OBJECTIVES Mycobacterium peregrinum is a species included in the Mycobacterium fortuitum complex, a member of the group of rapidly growing non-tuberculous mycobacteria (RGM). Only a few cases of infection with M. peregrinum have been reported, and no relevant review has been published. METHODS Following the treatment of a patient with M. peregrinum infection after plastic surgery, we undertook a review of the literature of previously reported cases of M. peregrinum infection. RESULTS Ten previously reported cases were identified. Like other cases of the M. fortuitum complex infections, the majority of M. peregrinum infections were related to surgical site infections and catheter-related infections. In the literature, most of the antibiotic regimens were based on a combination of quinolones with various antibiotics, and the duration of treatment ranged from 6 weeks to 4 months. CONCLUSION The fact that the optimal treatment for M. peregrinum infection has not yet been established has resulted in the use of a diverse range of therapies. It is important that clinicians carefully review each case so that a more appropriate treatment for M. peregrinum infections can be determined.

Anaerobic bacteremia: the yield of positive anaerobic blood cultures: patient characteristics and potential risk factors.

Abstract The anaerobic blood culture (AN) bottle is routinely used in Japan with little discussion as to its justification or validity. We retrospectively studied the AN bottle yield of obligate anaerobes and the characteristics of, and potential risk factors in, patients with anaerobic bacteremia during a 2-year period (1999–2000) at four university hospitals and one community hospital. Thirty-four of 18310 aerobic and anaerobic blood culture sets from 6215 patients taken at the university hospitals, and 35 of 2464 samples taken from 838 patients at the community hospital, yielded obligate anaerobes. Bacteroides species and Clostridium species accounted for 60% of the isolates. Fifty-seven patients from 69 blood culture sets containing anaerobes had clinically significant anaerobic bacteremia. Among these 57 patients, 24 (49%) were oncology patients, 40 (70%) had an obvious source of anaerobic infection, 15 (26%) had recent surgery and/or were in an immunosuppressed state. We concluded that the recovery rate of obligate anaerobes isolated from AN bottles was low, and the patients with anaerobic bacteremia had limited number of underlying diseases or potential risk factors for anaerobic infections. Therefore, anaerobic blood cultures may be selectively used according to the potential risk for anaerobic infections.

Effects on spectrum and susceptibility patterns of isolates causing bloodstream infection by restriction of fluoroquinolone prophylaxis in a hematology–oncology unit

The emergence of fluoroquinolone-resistant gram-negative organisms has been demonstrated in patients given fluoroquinolone prophylaxis. To prevent increases in resistant bacteria, we restricted prophylactic use of fluoroquinolones. The spectrum and susceptibility patterns of isolates causing bloodstream infection (BSI) were assessed in patients receiving chemotherapy during periods of routine prophylaxis (period A: October 2001 to May 2003) and restricted prophylaxis (period B: June 2003 to January 2005). The total number of patients receiving chemotherapy was 442 during period A and 365 during period B. No significant differences were seen between periods with respect to patient characteristics. BSI was identified in 42 patients (44 episodes) during period A and 69 patients (74 episodes) during period B. Incidence of BSI increased significantly from 10.0% (44/442) during period A to 20.3% (74/365) during period B (P < 0.0001). Rate of Enterobacteriaceae BSI increased significantly, from 2.0% (9/442) during period A to 8.2% (30/365) during period B (P < 0.0001). For all BSI episodes, the proportion of BSI with gram-positive cocci decreased from 63.6% (28/44) during period A to 44.6% (33/74) during period B (P = 0.045), while the proportion of BSI with Enterobacteriaceae increased from 20.5% (9/44) to 40.5% (30/74) (P < 0.0001). The proportion of fluoroquinolone-resistant Enterobacteriaceae BSI for all Enterobacteriaceae BSI decreased from 75% (9/12) during period A to 17% (5/30) during period B (P = 0.0078). Restriction of fluoroquinolone prophylaxis affects the etiology of BSI and reduces the proportion of drug-resistant organisms.

Comparison of the BDProbeTec ET system with the Cobas Amplicor PCR for direct detection of Mycobacterium tuberculosis in respiratory samples.

In the study presented here, the performance of the BDProbeTec ET system (Becton Dickinson, USA) was compared with the Roche Cobas Amplicor-PCR (Roche, Switzerland) to detect Mycobacterium tuberculosis complex (MTB) in clinical respiratory samples. The Bactec MGIT 960 liquid culture system (Becton Dickinson) was used as a reference method. A total of 411 samples were tested. Of the 93 culture-positive samples, both the BDProbeTec ET system and the Cobas Amplicor-PCR detected 87 (sensitivity, 93.5%). When only smear-negative samples were considered, the BDProbeTec ET exhibited a sensitivity of 50% and the Cobas Amplicor-PCR 60%. Specificity was 99.7% for the BDProbeTec ET system and 100% for the Cobas Amplicor-PCR. Percent agreement between the two nucleic amplification methods was 98.7%. Inhibition occurred in three (0.7%) samples in the BDProbeTec ET system. The high sensitivity and specificity of the BDProbeTec ET system suggest it is a useful method for the rapid and direct detection of MTB in smear-positive respiratory samples.

Regional spread of vanA- or vanB-positive Enterococcus gallinarum in hospitals and long-term care facilities in Kyoto prefecture, Japan.

Following an outbreak of vanA-positive Enterococcus faecium in 2005 in Kyoto prefecture, regional surveillance of vancomycin-resistant enterococci (VRE) was initiated. This revealed vanA- or vanB-positive Enterococcus gallinarum in multiple facilities. Eighty-eight vanA-positive E. gallinarum faecal carriers from 12 facilities and ten vanB-positive E. gallinarum faecal carriers from eight facilities were found. Pulsed-field gel electrophoresis profiles of the first isolate from each facility showed that 11 of the 12 vanA isolates and three of the eight vanB-positive E. gallinarum isolates belonged to a single clone. This study confirms the clonal spread of vanA- or vanB-positive E. gallinarum in a region and underlines the importance of surveillance of VRE for the presence of vancomycin resistance determinants.

Isothermal RNA Sequence Amplification Method for Rapid Antituberculosis Drug Susceptibility Testing of Mycobacterium tuberculosis

ABSTRACT RNA transcript quantification by an isothermal sequence amplification reaction was evaluated for susceptibility testing of 15 Mycobacterium tuberculosis strains. Agreement with the proportion method on Ogawa egg medium and the BACTEC MGIT 960 system was 100 and 87% for rifampin, 93 and 100% for isoniazid, 60 and 53% for ethambutol, and 80 and 80% for streptomycin, respectively.

Biliary bacteria in living related liver transplant recipients: microbiology and rapid detection system using flow cytometry.

Abstract Since cholangitis is a major complication in living related liver transplant (LRLT) recipients, rapid detection of biliary bacteria is necessary for the management of patients. We have developed a screening method for the detection of biliary bacteria using flow cytometry (FCM). Two hundred and seventy eight bile samples were obtained from 50 patients with biliary drainage tubes after LRLT at Kyoto University Hospital between July and September 2001. Of the 278 samples, 165 (59.3%) were culture-positive. The most common isolates were Enterococcus species, Pseudomonas species, Staphylococcus species, Klebsiella species, and Candida species. As the original FCM system was inadequate for specifically detecting bacteria in bile samples, we established the most appropriate gate and cut-off value from the particle distribution represented on scattergram of the forward-scattered light and fluorescent light intensity. The 3% cut-off value was most preferably related to the culture results. The FCM system detected biliary bacteria with a sensitivity of 93.9%, specificity of 81.4%, positive predictive value of 88.1%, negative predictive value of 90.2%, false-positive rate of 7.6%, false-negative rate of 3.6%, and percent agreement of 88.9% between FCM and culture. Therefore, FCM can be a useful method in clinical laboratories for the rapid screening for biliary bacteria in LRLT recipients.

Pre‐transplant risk factors predicting post‐transplant cytomegalovirus infection in liver transplant recipients

Cytomegalovirus (CMV) infection causes significant morbidity and mortality among transplant recipients. Although it is still not clear if a preemptive strategy is superior to a prophylactic strategy, many transplant programs elect for preemptive treatment for post‐transplant CMV infection. In order to improve the preemptive strategy, we analyzed a series of liver recipients by means of quantitative real‐time polymerase chain reaction (PCR). Ninety‐one liver transplant recipients were monitored by real‐time PCR for CMV, and the results were analyzed in terms of preoperative conditions. Multivariate analysis revealed fulminant hepatic failure as an underlying disease (odds ratio, 6.8; 95% CI, 1.2–39.2), while an ABO‐incompatible graft (odds ratio, 5.0; 95% CI, 1.3–19.1), and a serological combination of the donor (D) being positive with the recipient (R) being negative for CMV (D+/R−) (odds ratio, 5.8; 95% CI, 1.3–26.0) were independently associated with the development of significant CMV infection. Patients with risk factors had higher peak CMV DNA concentrations than those without, and developed CMV infections faster (P = 0.0002). Screening of recipients according to risk factors and PCR monitoring may result in an optimization of the preemptive strategy.