Antimicrobial therapy and outcome of methicillin-resistant Staphylococcus aureus endocarditis: A retrospective multicenter study in Japan

BACKGROUND

MRSA (methicillin-resistant Staphylococcus aureus)-infective endocarditis (IE) is associated with high morbidity and mortality. This study aimed to assess data from patients with MRSA-IE across multiple facilities in Japan, with a specific focus on antimicrobial therapy and prognosis.

METHODS

This retrospective study enrolled patients with a confirmed diagnosis of IE attributed to MRSA, spanning the period from January 2015 to April 2019.

RESULTS

Sixty-four patients from 19 centers were included, with a median age of 67 years. The overall mortality rate was 28.1% at 30 days, with an in-hospital mortality of 45.3%. The most frequently chosen initial anti-MRSA agents were glycopeptide in 67.2% of cases. Daptomycin and linezolid were selected as initial therapy in 23.4% and 17.2% of cases, respectively. Approximately 40% of all patients underwent medication changes due to difficulty in controlling infection or drug-related side effects. Significant prognostic factors by multivariable analysis were DIC for 30-day mortality and surgical treatment for 30-day and in-hospital mortality. For vancomycin as initial monotherapy, there was a trend toward a worse prognosis for 30-day and in-hospital mortality (OR, 6.29; 95%CI, 1.00-39.65; p = 0.050, OR, 3.61; 95%CI, 0.93-14.00; p = 0.064). Regarding the choice of initial antibiotic therapy, statistical analysis did not show significant differences in prognosis.

CONCLUSION

Glycopeptide and daptomycin were the preferred antibiotics for the initial therapy of MRSA-IE. Antimicrobial regimens were changed for various reasons. Prognosis was not significantly affected by choice of antibiotic therapy (glycopeptide, daptomycin, linezolid), but further studies are needed to determine which antimicrobials are optimal as first-line agents.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of the Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2019-2020: General view of the pathogens' antibacterial susceptibility

The trends and prevalence of antimicrobial susceptibility of pathogens vary by country, region, and time. Long-term regular surveillance is required to investigate trends in the antimicrobial resistance of various isolated bacterial pathogens. We report the results of a nationwide surveillance on the antimicrobial susceptibility of bacterial respiratory pathogens in Japan conducted by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology. The isolates were collected from clinical specimens obtained from adult patients who visited a collaborating medical facility between June 2019 and December 2020 and were diagnosed with respiratory tract infections by a physician. Antimicrobial susceptibility testing was performed in a centralized laboratory according to the methods recommended by the Clinical and Laboratory Standards Institute. Susceptibility testing was performed for 932 strains (201 Staphylococcus aureus, 158 Streptococcus pneumoniae, 6 S. pyogenes, 136 Haemophilus influenzae, 127 Moraxella catarrhalis, 141 Klebsiella pneumoniae, and 163 Pseudomonas aeruginosa) collected from 32 facilities in Japan. The proportions of methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae were 35.3% and 0%, respectively. In H. influenzae, 16.2% and 16.9% were β-lactamase-producing ampicillin resistant and β-lactamase-negative ampicillin resistant, respectively. Extended-spectrum β-lactamase-producing K. pneumoniae accounted for 5.0% of all K. pneumoniae infections. Carbapenemase-producing K. pneumoniae and multi-drug-resistant P. aeruginosa with metallo-β-lactamase were not detected in this study. This surveillance will be a useful reference for treating respiratory infections in Japan and will provide evidence to enhance the appropriate use of antimicrobial agents.

Genetic epidemiology using whole genome sequencing and haplotype networks revealed the linkage of SARS-CoV-2 infection in nosocomial outbreak

BACKGROUND

A characteristic feature of SARS-CoV-2 is its ability to transmit from pre- or asymptomatic patients, complicating the tracing of infection pathways and causing outbreaks. Despite several reports that whole genome sequencing (WGS) and haplotype networks are useful for epidemiologic analysis, little is known about their use in nosocomial infections.

AIM

We aimed to demonstrate the advantages of genetic epidemiology in identifying the link in nosocomial infection by comparing single nucleotide variations (SNVs) of isolates from patients associated with an outbreak in Showa University Hospital.

METHODS

We used specimens from 32 patients in whom COVID-19 had been diagnosed using clinical reverse transcription-polymerase chain reaction tests. RNA of SARS-CoV-2 from specimens was reverse-transcribed and analysed using WGS. SNVs were extracted and used for lineage determination, phylogenetic tree analysis, and median-joining analysis.

FINDINGS

The lineage of SARS-CoV-2 that was associated with outbreak in Showa University Hospital was B.1.1.214, which was consistent with that found in the Kanto metropolitan area during the same period. Consistent with canonical epidemiological observations, haplotype network analysis was successful for the classification of patients. Additionally, phylogenetic tree analysis revealed three independent introductions of the virus into the hospital during the outbreak. Further, median-joining analysis indicated that four patients were directly infected by any of the others in the same cluster.

CONCLUSION

Genetic epidemiology with WGS and haplotype networks is useful for tracing transmission and optimizing prevention strategies in nosocomial outbreaks.

Selection of Oral Antifungals for Initial Maintenance Therapy in Chronic Pulmonary Aspergillosis: A Longitudinal Analysis

BACKGROUND

There are limited data for direct comparisons of the efficacy of oral itraconazole (ITCZ) and oral voriconazole (VRCZ) therapy in the treatment of chronic pulmonary aspergillosis (CPA).

METHODS

We conducted a retrospective, follow-up, observational study of CPA patients enrolled in 2 previous multicenter trials.

RESULTS

Of the 273 CPA patients, 59 and 101 patients started maintenance therapy with oral ITCZ and oral VRCZ, respectively, just after the end of acute intravenous therapy in each trial. At the end of the observation period in this follow-up study (median observation period, 731 days), the percentage of patients who showed improvement was lower in the ITCZ group than in the VRCZ group (18.2% vs 40.0%). However, after including stable patients, the percentages were 50.9% and 52.6%, respectively, in the ITCZ and VRCZ groups, which were not significantly different (P = .652). Multivariable Cox regression analysis showed no significant influence of the choice of initial maintenance treatment (ITCZ or VRCZ) on overall mortality as well as CPA-associated mortality. Multivariable logistic regression showed that oral ITCZ selection for initial maintenance therapy was an independent risk factor for hospital readmission and switching to other antifungal agents (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.3-7.5 and OR, 5.7; 95% CI, 2.0-15.7, respectively).

CONCLUSIONS

Oral VRCZ for initial maintenance therapy showed better effectiveness than oral ITCZ for clinical improvement in CPA patients. There was no difference in crude mortality between initial maintenance therapy with VRCZ and ITCZ, especially in elderly CPA patients.

CLINICAL TRIALS REGISTRATION

UMIN000007055.

Successful Treatment of Breakthrough Trichosporon asahii Fungemia by the Combination Therapy of Fluconazole and Liposomal Amphotericin B in a Patient with Follicular Lymphoma

Invasive trichosporonosis is a rare and lethal fungal infection that occurs in immunocompromised patients. Breakthrough trichosporonosis can occur in patients treated with echinocandins since Trichosporon spp. are resistant to these antifungal agents. We report a case of breakthrough Trichosporon asahii fungemia. A 62-year-old Japanese woman with relapsed follicular lymphoma was treated empirically with broad-spectrum antibiotics and micafungin due to an intermittent fever during reinduction chemotherapy. After four cycles of anti-cancer chemotherapy, she experienced a high neutropenic fever and T. asahii was subsequently detected from a blood culture. The patient was not given voriconazole due to the contraindication for use with carbamazepine, and she was successfully treated with fluconazole plus liposomal amphotericin B without any serious complications. The combined therapy of fluconazole and liposomal amphotericin B may therefore be useful in treating T. asahii fungemia, especially in patients receiving antiepileptic agents.

Combination treatment of short-course systemic corticosteroid and favipiravir in a successfully treated case of critically ill COVID-19 pneumonia with COPD

Use of systemic corticosteroids for the treatment for coronavirus disease 2019 (COVID-19) among chronic obstructive pulmonary disease (COPD) patients is not well described. A 58-year-old man with fever and progressive dyspnea was admitted to the Showa University Hospital, and showed severe respiratory failure which needed mechanical ventilation. His chest computed tomography scanning showed emphysema and bilateral ground-glass opacity caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. He received 30 mg prednisolone for five days with antiviral drug of favipiravir, and was successfully extubated on day five. A SARS-CoV-2 polymerase chain reaction (PCR) test became negative on day 15. He was discharged on day 21. Serum IgM and IgG antibodies against SARS-CoV-2 converted to positive on day 7 and they kept positive on day 54 for both IgM and IgG. Combination treatment of short-course systemic corticosteroid and favipiravir might improve the prognosis for critically ill COVID-19 pneumonia with COPD without negative influence on viral clearance or antibody production.

The incidence of endophthalmitis or macular involvement and the necessity of a routine ophthalmic examination in patients with candidemia

Background

The incidence of ocular candidiasis (OC) in patients with candidemia varies across different reports, and the issue of whether routine ophthalmoscopy improves outcomes has been raised. This study investigated the incidence of OC and evaluate whether the extent of OC impacts the clinical outcomes.

Methods

This retrospective study included non-neutropenic patients with candidemia who underwent treatment at one of 15 medical centers between 2010 and 2016. Chorioretinitis without other possible causes for the ocular lesions and endophthalmitis was classified as a probable OC. If signs of chorioretinitis were observed in patients with a systemic disease that causes similar ocular lesions, they were classified as a possible OC.

Results

In total, 781 of 1089 patients with candidemia underwent an ophthalmic examination. The prevalence of OC was 19.5%. The time from the collection of a positive blood culture to the initial ophthalmic examination was 5.0 ± 3.9 days in patients with OC. The leading isolate was Candida albicans (77.9%). Possible OC was associated with unsuccessful treatments (resolution of ocular findings) (odds ratio: 0.354, 95% confidence interval: 0.141–0.887), indicating an overdiagnosis in patients with a possible OC. If these patients were excluded, the incidence fell to 12.8%. Endophthalmitis and/or macular involvement, both of which require aggressive therapy, were detected in 43.1% of patients; a significantly higher incidence of visual symptoms was observed in these patients.

Conclusion

Even when early routine ophthalmic examinations were performed, a high incidence of advanced ocular lesions was observed. These results suggest that routine ophthalmic examinations are still warranted in patients with candidemia.

Bacteremia complicating urinary tract infection by Pseudomonas aeruginosa: Mortality risk factors

OBJECTIVES

To examine the clinical risk factors for death within 30 days of diagnosis of Pseudomonas aeruginosa-causing bacteremia after a urinary tract infection.

METHODS

A total of 62 patients with Pseudomonas aeruginosa isolated from both urine and blood at the same episode from January 2009 to December 2016 were enrolled in the present study. We retrospectively investigated clinical risk factors for death by comparison between surviving patients and those who died within 30 days after diagnosis of P. aeruginosa bacteremia. The comparison for risk factors for bacteremia-related death included 31 categories, such as age, laboratory data, underlying diseases, clinical history, history of surgery, care in the intensive care unit, P. aeruginosa susceptibility to the antibiotics used at the time of bacteremia diagnosis and consultation with urological department.

RESULTS

The study included 48 men and 14 women aged 71.3 ± 10.4 years. Nine patients (14.5%) died of P. aeruginosa bacteremia. Statistical analysis showed that non-survivors had significantly lower albumin levels than survivors (2.07 ± 0.62 vs 2.62 ± 0.65; P = 0.023). The non-survivors had significantly higher rates of ventilator use, history of heart disease, septic shock and lower rates of consultation with urological departments after diagnosis (P < 0.05).

CONCLUSIONS

Patients with bacteremia complicating urinary infection by P. aeruginosa have a low death rate. Earlier intervention by urologists might improve patients' outcome. Lower albumin levels, ventilator use, history of heart disease and septic shock are factors associated with higher mortality rate.

Molecular epidemiologic study of Clostridium difficile infections in university hospitals: Results of a nationwide study in Japan

We conducted a nationwide molecular epidemiological study of Clostridium difficile infection (CDI) in Japan investigated the correlation between the presence of binary toxin genes and CDI severity. This is the first report on molecular epidemiological analyses for CDI in multiple university hospitals in Japan, to our knowledge. We examined 124,484 hospitalized patients in 25 national and public university hospitals in Japan between December 2013 and March 2014, investigating antimicrobial susceptibilities and toxin-related genes for C. difficile isolates from stools. Epidemiological genetic typing was performed by PCR-ribotyping and repetitive sequence-based (rep)-PCR to examine the genetic similarities. The results detected toxin A-positive, toxin B-positive, binary toxin-negative (A⁺B⁺CDT^-) detected from 135 isolates (80.8%) and toxin A-negative, toxin B-positive, binary toxin-negative (A^-B⁺CDT^-) in 23 (13.8%). Toxin A-positive, toxin B-positive, and binary toxin-positive (A⁺B⁺CDT⁺) were seen in 9 isolates (5.4%). Vancomycin (n = 81, 37.7%) or metronidazole (n = 88, 40.9%) therapies were undertaken in analyzed cases. Ribotypes detected from isolates were 017/subgroup 1, 070, 078, 126, 176, 449, 475/subgroup 1, 499, 451, 566 and newtypes. Rep-PCR classified 167 isolates into 28 cluster groups including 2-15 isolates. In addition, 2 pairs of strains isolated from different institutions belonged to the same clusters. Seven out of 9 (77.8%) of the patients with binary toxin producing strains had "mild to moderate" outcome in evaluated symptoms. In conclusion, we found that binary toxin did not show regional specificity and had no relevance to severity of CDI.

Acquisition of antimicrobial-resistant variants in repeated infections caused by Pseudomonas aeruginosa revealed by whole genome sequencing

Pseudomonas aeruginosa, responsible for serious nosocomial-acquired infections, possesses intrinsic antibiotic resistance mechanisms and commonly exhibits multidrug resistance. Here, we report the evolving resistance profiles of strains isolated from the sputum of a patient being treated for repeated P. aeruginosa infections following cancer resection. Whole genome sequencing of six isolates obtained over a 2-month period revealed two key single nucleotide polymorphisms in the mexR and gyrB genes that affected efflux pump expression and antimicrobial resistance.

The development of diffuse panbronchiolitis during the treatment with long-term, low-dose clarithromycin for chronic sinusitis

Diffuse panbronchiolitis (DPB) is a progressive inflammatory airway disease characterized by a chronic cough, copious sputum expectation, dyspnea, and chronic sinusitis. Owing to the long-term treatment of low-dose macrolides, the prognosis has been remarkably improved. However, in some cases, patients are refractory to macrolides, and the subsequent treatment strategies are controversial. We herein present a patient with the onset of DPB during treatment with long-term, low-dose clarithromycin (CAM) for chronic sinusitis who was successfully treated by switching to long-term treatment with normal-dose CAM. We should recognize that DPB may develop in patients with chronic sinusitis despite treatment with a long-term, low-dose macrolide. We also propose that increasing the dose of macrolide may be a useful strategy for treating refractory patients.

Invasive Scopulariopsis alboflavescens infection in patient with acute myeloid leukemia

Scopulariopsis alboflavescens is a soil saprophyte that is widely distributed in nature. Recently, there have been increasing number of reports of invasive infections with Scopulariopsis species in immunocompromised patients. In this report, we described an adult woman with acute myeloid leukemia and who developed S. alboflavescens pneumonia. Liposomal amphotericin B and voriconazole combination therapy was unsuccessful and the patient died because of pneumonia. Scopulariopsis is highly resistant to available antifungal agents and almost invariably fatal. This case report should alert clinicians to the importance of listing Scopulariopsis as a pathogenic fungus in immunocompromised patients.

Risk factors for death from Stenotrophomonas maltophilia bacteremia

PURPOSE

Stenotrophomonas maltophilia has low pathogenicity potential, but if it causes bacteremia it can be fatal, because it has shown high resistance to many antibiotics and can be difficult to treat. Patient death from S. maltophilia bacteremia has increased since 2014 in our hospital. In this study, we investigated risk factors for death due to S. maltophilia bacteremia.

METHODS

Seventy patients from the hospital database with S. maltophilia bacteremia between January 2010 and July 2017 were investigated. We retrospectively analyzed risk factors including gender, age, wards, hospitalized duration, clinical history, devices, source of S. maltophilia identification, polymicrobial bacteremia, prior antimicrobial therapy, antimicrobial therapy after bacteremia, and resistance to antibiotics. The statistical analysis was performed to compare the period from 2010 to 2013 to from 2014 to 2017.

RESULTS

Comparing the 2010-2013 period to the 2014-2017 period, it revealed that history of hospitalization, identification of S. maltophilia from sputum, polymicrobial bacteremia, prior carbapenem use, and mortality was significantly different in S. maltophilia bacteremia (p = 0.028, p = 0.004, p < 0.001, p = 0.034, and p = 0.007, respectively). Comparison between non-survivors and survivors for 2010-2013 and 2014-2017 found ICU admission and ventilator use were seen more often in non-survivors (p = 0.030 vs p = 0.013 and p = 0.027 vs p = 0.010, respectively).

CONCLUSIONS

Our analyses showed increase in mortality from S. maltophilia bacteremia from 2014 to 2017, and that non-survivors had a higher frequency of ICU admission and ventilator use in both the 2010-2013 and 2014-2017 periods. There were more combination antimicrobial therapy cases after bacteremia in 2014-2017. Further prospective studies with larger numbers of patients should be undertaken for definitive conclusions.

Determination of the antimicrobial susceptibility and molecular profile of clarithromycin resistance in the Mycobacterium abscessus complex in Japan by variable number tandem repeat analysis

Mycobacterium abscessus complex, including three subspecies-M. abscessus, M. massiliense, and M. bolletii-is resistant to a variety of antibiotics so limited treatment options are available. The susceptibility of these subspecies to antimicrobial agents depends in particular on the erm(41) sequevar and rrl mutations in the 23S rRNA, which are potentially related to clarithromycin (CLR) resistance. The purpose of this study was to carry out identification and molecular characterization of these subspecies based on variable number of tandem repeats (VNTR) analysis. Twenty-four M. abscessus complex strains were identified as M. abscessus and M. massiliense and these subspecies could be discriminated between based on their resistance to CLR, as determined by truncation or mutation of erm(41) or mutation of rrl, as illustrated by their VNTR patterns. In conclusion, we confirmed that the CLR susceptibility profiles could be differentiated according to the subspecies of M. abscessus complex strains by their VNTR patterns.

Long-term efficacy of comprehensive multidisciplinary antibiotic stewardship programs centered on weekly prospective audit and feedback

OBJECTIVE

To evaluate the long-term effects of comprehensive antibiotic stewardship programs (ASPs) on antibiotic use, antimicrobial-resistant bacteria, and clinical outcomes.

DESIGN

Before-after study.

SETTING

National university hospital with 934 beds.

INTERVENTION

Implementation in March 2010 of a comprehensive ASPs including, among other strategies, weekly prospective audit and feedback with multidisciplinary collaboration.

METHODS

The primary outcome was the use of antipseudomonal antibiotics as measured by the monthly mean days of therapy per 1000 patient days each year. Secondary outcomes included overall antibiotic use and that of each antibiotic class, susceptibility of Pseudomonas aeruginosa, the proportion of patients isolated methicillin-resistant Staphylococcus aureus (MRSA) among all patients isolated S. aureus, the incidence of MRSA, and the 30-day mortality attributable to bacteremia.

RESULTS

The mean monthly use of antipseudomonal antibiotics significantly decreased in 2011 and after as compared with 2009. Susceptibility to levofloxacin was significantly increased from 2009 to 2016 (P = 0.01 for trend). Its susceptibility to other antibiotics remained over 84% and did not change significantly during the study period. The proportion of patients isolated MRSA and the incidence of MRSA decreased significantly from 2009 to 2016 (P < 0.001 and = 0.02 for trend, respectively). There were no significant changes in the 30-day mortality attributable to bacteremia during the study period (P = 0.57 for trend).

CONCLUSION

The comprehensive ASPs had long-term efficacy for reducing the use of the targeted broad-spectrum antibiotics, maintaining the antibiotic susceptibility of P. aeruginosa, and decreasing the prevalence of MRSA, without adversely affecting clinical outcome.

Comparison of antibiotics use, urinary tract infection (UTI)-causative bacteria and their antibiotic susceptibilities among 4 hospitals with different backgrounds and regions in Japan

In this study, we compared the antibiotic use, urinary tract infection-causative bacteria and their antibiotic susceptibilities among four hospitals with different backgrounds and regions in Japan in 2014. Frequency of antibiotic use (antibiotic use density: AUD/all AUD) were: ampicillin: 0.21-20.3 (median: 1.6) and cefazolin: 0.8-34.2 (2.5), representatively. The antibiotic resistant rates of Escherichia coli were ampicillin: 1.1-52.3% (median: 51.8%), piperacillin: 47.9-49.1% (48.0%), cefazolin: 23.2-34.1% (28.9%), levofloxacin: 36.6-43.8% (40.2%).We found that there were significant correlations (1) between antibiotic resistance of E. coli and annual total amount of antibiotic use (p = 0.017), annual number of days of antibiotic use (p = 0.002) and days of therapy (DOT, p = 0.002), and (2) between antibiotic resistance of extended-spectrum β-lactamase-producing bacteria and annual number of days of antibiotic use (p = 0.004) and DOT (p = 0.004) in a rehabilitation hospital. These results suggested that more antibiotic uses could lead to antibiotic resistances. Further analyses with more number of data are being undertaken.

Evaluation of Bioequivalence Between the New Procaterol Hydrochloride Hydrate Dry Powder Inhaler and the Approved Dry Powder Inhaler in Patients With Asthma in a Randomized, Double-Blind, Double-Dummy, Crossover Comparison Study: A Phase 3 Study

Procaterol hydrochloride hydrate (procaterol) is a β₂‐adrenergic receptor agonist that induces a strong bronchodilatory effect. The procaterol dry powder inhaler (DPI) has been frequently used in patients with bronchial asthma or chronic obstructive pulmonary disease. We evaluated the bioequivalence and safety between the new procaterol DPI (new DPI) and the approved procaterol DPI (approved DPI). This study was a randomized, double‐blind, double‐dummy, crossover comparison to evaluate the pharmacodynamic equivalence of the new DPI and the approved DPI in patients with bronchial asthma. Primary efficacy variables were area under the concentration‐time curve (AUC) forced expiratory volume in the first second (FEV₁)/h and maximum FEV₁ during the 480‐minute measurement period. Patients were divided into 2 groups, New‐DPI‐First (n = 8) and Approved‐DPI‐First (n = 8), according to the investigational medical product that was administered first. Patients inhaled 20 μg of procaterol in each period. FEV₁ was measured by a spirometer at predose and at 15, 30, 60, 90, 120, 180, 240, 360, and 480 minutes after each investigational medical product administration. Equivalence was evaluated by confirming that the 2‐sided 90%CIs for the difference between the new and the approved DPI in means of AUC (FEV₁)/h and maximum FEV₁ were within the acceptance criteria of –0.15 to 0.15 L. The difference in means of AUC (FEV₁)/h and maximum FEV₁ was 0.041 L and 0.033 L, respectively, and the 90%CI was 0.004 to 0.078 L and –0.008 to 0.074 L, respectively. These CIs were both within the acceptance criteria. The new DPI was assessed as being bioequivalent to the approved DPI.

Improved bacterial identification directly from urine samples with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

BACKGROUND

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) contributes to rapid identification of pathogens in the clinic but has not yet performed especially well for Gram-positive cocci (GPC) causing complicated urinary tract infection (UTI). The goal of this study was to investigate the possible clinical use of MALDI-TOF MS as a rapid method for bacterial identification directly from urine in complicated UTI.

METHODS

MALDI-TOF MS was applied to urine samples gathered from 142 suspected complicated UTI patients in 2015-2017. We modified the standard procedure (Method 1) for sample preparation by adding an initial 10 minutes of ultrasonication followed by centrifugation at 500 g for 1 minutes to remove debris such as epithelial cells and leukocytes from the urine (Method 2).

RESULTS

In 133 urine culture-positive bacteria, the rate of corresponded with urine culture in GPC by MALDI-TOF MS in urine with standard sample preparation (Method 1) was 16.7%, but the modified sample preparation (Method 2) significantly improved that rate to 52.2% (P=.045). Method 2 also improved the identification accuracy for Gram-negative rods (GNR) from 77.1% to 94.2% (P=.022). The modified Method 2 significantly improved the average MALDI score from 1.408±0.153 to 2.166±0.045 (P=.000) for GPC and slightly improved the score from 2.107±0.061 to 2.164±0.037 for GNR.

CONCLUSION

The modified sample preparation for MALDI-TOF MS can improve identification accuracy for complicated UTI causative bacteria. This simple modification offers a rapid and accurate routine diagnosis for UTI, and may possibly be a substitute for urine cultures.

Shock due to urosepsis: A multicentre study

INTRODUCTION

Urosepsis is a severe infection that can cause shock afterwards. The purpose of this study is to investigate the clinical and bacterial risk factors for shock in those cases with urosepsis caused by urinary tract infection in a multicentre study.

METHODS

Our study included 77 consecutive urosepsis cases from four hospitals. We examined factors such as patient characteristics, underlying disease, serum white blood cell (WBC) count, platelet count, C-reactive protein (CRP) level at the time of diagnosis of urosepsis, urinary tract occlusion, causative bacteria, and bacterial antibiotic susceptibilities. Statistical analyses were performed to assess the potential risk factors for shock during the clinical course of urosepsis by a multivariate analysis.

RESULTS

We had 38 male and 39 female patients aged 25-104 (median 73). Underlying diseases included cancers (n=22, 28.6 %) and diabetes mellitus (n=17, 22.1 %). Positive blood culture was seen in 74 cases; these involved 88 bacterial strains, of which Escherichia coli was the most common (34 strains, 38.6 %). There were 31 cases with shock (40.3 %) and multivariate analyses demonstrated that serum CRP was the only clinical risk factor for shock due to urosepsis.

CONCLUSIONS

Our study demonstrated that serum CRP was a risk factor for shock during urosepsis in a multicentre analysis. Further prospective studies with a greater number of patients are needed to draw more definitive conclusions.

Should We Change the Initial Treatment of Renal or Retroperitoneal Abscess in High Risk Patients?

INTRODUCTION

This study examined the risk factors for initial treatment failure in renal or retroperitoneal abscess as a multicenter study.

MATERIALS AND METHODS

This retrospective analysis investigated consecutive patients with renal or retroperitoneal abscess who were hospitalized in Japan. The outcomes of these patients were classified into "cured" and "failure or recurrence." The potential clinical risk factors examined were abscess size, diabetes mellitus, major organ failure, laboratory data, fever, drainage, and causative organisms, for instance.

RESULTS

Of the 74 patients, 40 (54.1%) were diagnosed with renal abscess and 34 (45.9%) with retroperitoneal abscess, 51 (68.9%) were cured by initial treatments, and 23 (31.1%) underwent failure or relapse; 33 (44.6%) were men and 41 (55.4%) were women. In detail, 36 patients were cured by conservative therapy only. Our multivariate analysis data showed that renal failure was the only significant factor for initial treatment failure (p = 0.0281).

CONCLUSIONS

Our multivariate analysis showed that renal failure was a significant risk factor for initial treatment failure or recurrence.

[The Deveroppment of Screening Methods Using the Disk Diffusion Method for Carbapenemase-producing Enterobacteriaceae]

Carbapenem-resistant Enterobacteriaceae (CRE) are increasing globally. Particularly, carbapenemase-producing Enterobacteriaceae (CPE) are of concern. Rapid and accurate detection of these strains is critical for appropriate antimicrobial use and hospital infection control. In the present study, criteria for CPE screening were examined using a carbapenem susceptibility disk. Carbapenemase producers showed minimal inhibition zones for faropenem (5 μg): 6-12 mm (mean: 6.9 mm). Some strains with the IMP-6 genotype showed inhibition zones of >30 mm for imipenem (10 μg) and biapenem (10 μg). All strains that formed inhibition zones for FRPM had the IMP-6 genotype. The cut off values of carbapenemase-producers, determined by ROC analysis, were 12 mm for FRPM, 24 mm for meropenem (10 μg), 29 mm for BIPM, 25 mm for doripenem (10 μg), 26 mm for IPM, and 24 mm for panipenem (10 μg). Thus, the sensitivity was the highest (100%) for FRPM. Specificities were 93.44% for MEPM and DRPM and 85.25% for FRPM. Consequently, a drug sensitivity test using FRPM (5 μg) disks facilitates simple and accurate CPE screening.

A Prospective Study of the Efficacy, Safety and Pharmacokinetics of Enteral Moxifloxacin in the Treatment of Hemodialysis Patients with Pneumonia

Objectives To investigate the efficacy of oral moxifloxacin (MFLX) as a treatment for pneumonia in hemodialysis (HD) patients and the pharmacokinetic (PK) profile of MFLX after oral administration. Methods Thirteen adult patients who required HD due to chronic renal failure were enrolled in the present study, which was performed to investigate the treatment of community-acquired pneumonia in HD patients. A standard dose of MFLX (400 mg, once daily) was administered. The therapy was continued, discontinued, or switched to another antibiotic depending on the response of the pneumonia to MFLX. A population PK model was developed using the post-hoc method. Results In total, 13 HD patients with pneumonia (male, n=7; female, n=6) were enrolled in the present study. The evaluation on the 3rd day showed that treatment was successful in 11 patients (84.6%) and that 10 patients were cured (76.9%). In the one case in which MFLX treatment failed, the patient was cured by switching to ceftriaxone (CTRX) (2 g, intravenously) plus levofloxacin (LVFX) (250 mg, orally). The causative bacterium in this male patient was P. aeruginosa. It did not display resistance to fluoroquinolones. One patient had liver dysfunction due to MFLX. The estimated PK parameters of MFLX were as follows: AUC_0→24, 61.04±17.74 μg h/mL; C_max, 5.25±1.12 μg/mL; and C_trough, 1.15±0.45 μg/mL. The PK parameters of MFLX among the patients in whom adverse events occurred or in whom a cure was not achieved did not differ from those of the other patients to a statistically significant extent. Conclusion MFLX showed good efficacy and safety in HD patients with community-acquired pneumonia and the results of the PK analysis were favorable. Further prospective studies with larger numbers of patients will be needed to draw definitive conclusions.

[Antifungal susceptibility and drug-resistant mechanism of Trichosporon]

Most cases of deep-seated trichosporonosis develop in patients with neutropenia, but it has recently been reported that breakthrough infections with Trichosporon species can develop during the use of candin family of antifungal agents. This is due to the primary resistance of the causal fungus, Trichosporon asahii (T. asahii), to the candin agents. On the other hand, there has been a case report of infection with Trichosporon that presented high-level resistance to the azole family of antifungal agents. Therefore, the possibility that the frequent use of azole agents may lead to secondary resistance to these agents is a cause for concern. Since trichosporonosis is a relatively rare infectious disease, there has been no established breakpoint for this fungus to various antifungal agents, wherein we cannot precisely confirm its sensitivity or resistance to the agents. However, our experiment demonstrated one of the processes for acquired drug resistance, wherein the minimal inhibitory concentration of fluconazole for T. asahii was markedly elevated after its long-term in vitro exposure to the drug. Although the mechanisms for drug-resistance of Trichosporon species are unknown, it is supposed that they are the same as the mechanisms found in Candida and Aspergillus species, namely, modification of target molecules or decrease of access to the molecules. Since cases of trichosporonosis are likely to increase in the future, we believe that there is an urgent need to establish the breakpoint for T. asahii based on large-scale drug sensitivity tests, as well as to elucidate its drug-resistance mechanisms.

Effects of Sulfamethoxazole-Trimethoprim on Airway Colonization with Pneumocystis jirovecii

Reactivation of latent infection is considered to be the main mechanism underlying the development of Pneumocystis pneumonia in immunosuppressed patients. We retrospectively assessed the effects of prophylactic administration of sulfamethoxazole-trimethoprim on the development of P. pneumonia and airway colonization with P. jirovecii in patients undergoing examinations to diagnose or rule out P. pneumonia. Polymerase chain reaction was performed to detect P. jirovecii in bronchoalveolar lavage fluid or sputum of 60 consecutive patients between 2004 and 2012. No patients who received the prophylactic administration of sulfamethoxazole-trimethoprim (n = 10) developed P. pneumonia or demonstrated airway colonization with P. jirovecii, and none of the patients who developed P. pneumonia (n = 11) or showed colonization (n = 9) had received prophylactic treatment. Furthermore, 20 (40%) of 50 patients without prophylactic treatment showed positive results on the P. jirovecii DNA polymerase chain reaction, but all 10 patients who had prophylactic treatment showed negative results (Fisher's exact test, P = 0.02). Therefore, the prophylactic administration of sulfamethoxazole-trimethoprim has potential to be effective in preventing P. pneumonia as well as eliminating airway colonization with P. jirovecii. Further studies targeting large cohorts of patients with a variety of underlying diseases are required to develop recommendations regarding the prophylactic administration of sulfamethoxazole-trimethoprim.

A retrospective analysis to estimate target trough concentration of vancomycin for febrile neutropenia in patients with hematological malignancy

BACKGROUND

The target trough concentration of vancomycin in patients with febrile neutropenia has not been reported. The aim of this study was to estimate the target trough concentration for febrile neutropenia in patients with hematological malignancy.

METHODS

In this retrospective, single-center, observational cohort study, 63 hospitalized patients with hematological malignancy who were treated with vancomycin for febrile neutropenia due to bacteriologically documented or presumptive Gram-positive infections were analyzed.

RESULTS

A significant difference in the first trough concentration of vancomycin was observed between the response and non-response groups, and between the nephrotoxicity and non-nephrotoxicity groups. Multiple logistic regression analyses identified the first trough concentration as the only independent variable associated with clinical efficacy and nephrotoxicity of vancomycin. The areas under the ROC curves were 0.72 and 0.83 for clinical efficacy and nephrotoxicity, respectively. The cut-off values of the first trough concentration were 11.1 μg/ml for clinical efficacy (sensitivity 60%, specificity 87%) and 11.9 μg/ml for nephrotoxicity (sensitivity 77%, specificity 82%).

CONCLUSIONS

These results suggest a relationship of trough vancomycin concentration with clinical efficacy and incidence of nephrotoxicity. We propose a target trough vancomycin concentration of around 11.5 μg/ml for febrile neutropenia in patients with hematological malignancy.

Clinical practice guidelines for therapeutic drug monitoring of arbekacin: a consensus review of the Japanese Society of Chemotherapy and the Japanese Society of Therapeutic Drug Monitoring

Arbekacin (ABK) was approved and widely used in Japan for treatment of patients infected with MRSA, and TDM was introduced in clinical practice. The Japanese Society of Chemotherapy and the Japanese Society of Therapeutic Drug Monitoring decided to develop a clinical practice guidelines for TDM of ABK for the following reasons. First, although the daily dose of 150-200 mg was approved in Japan, recent PK-PD studies revealed that higher serum concentration is required to achieve better clinical efficacy and several findings concerning the usefulness of higher dosage regimen have obtained recently. Second, although maximal concentrations that obtained immediately after the end of administration (Cmax) was generally adopted, the serum concentration at 1 h after initiation of administration [peak serum concentration (Cpeak)] proved to be more suitable as an efficacy indicator of aminoglycosides. Lastly, as ABK is approved only in Japan, no international practice guideline for TDM has not been available in ABK to date. This guideline evaluated the scientific data associated with serum ABK monitoring and provided recommendations based on the available evidence. Potential limitations of this guideline, however, include the findings that few prospective clinical trials of TDM of ABK are available in the treatment of MRSA infections and that most of the published literature describes observational studies.

Inhibitory effects of pitavastatin on fibrogenic mediator production by human lung fibroblasts

AIMS

Idiopathic pulmonary fibrosis continues to be a devastating clinical disorder for which there are few therapeutic options, and the pathogenesis of this disease remains largely unknown. Statins are inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in cholesterol biosynthesis, and they have been reported to exert pleiotropic effects on the cellular signaling involved in tissue inflammation and in organ fibrosis/remodeling. We examined the preventive effects of statins on fibrogenic mediator expression and production in normal human lung fibroblasts (NHLF).

MAIN METHODS

NHLF were pretreated with 100nM pitavastatin or medium alone (control), and were then stimulated with transforming growth factor-β1 (TGF-β1). mRNA expression and protein secretion of several mediators from cells were analyzed by real-time polymerase chain reaction, enzyme-linked immunosorbent assay or multiplex assay.

KEY FINDINGS

TGF-β1-induced expression or production of mediators, such as collagen-1, vascular endothelial growth factor and chemokine C-X-C motif ligand 8, in NHLF pretreated with pitavastatin was significantly suppressed with inhibition of Smad-3 phosphorylation, as compared to untreated controls. In addition, the inhibitory effects of pitavastatin were negated by addition of mevalonate.

SIGNIFICANCE

Pitavastatin appeared to inhibit TGF-β1-induced fibrogenic mediator production from lung fibroblasts via the mevalonic cascade. Although further evaluation of the signaling pathways for these phenomena is necessary, our results suggest the potential benefits of pitavastatin.

Association of sustained high plasma trough concentration of voriconazole with the incidence of hepatotoxicity

BACKGROUND

Therapeutic drug monitoring (TDM) of voriconazole is important to optimize efficacy and to minimize toxicity and intolerance. In this study, we evaluated the effect of sustained high plasma trough concentration of voriconazole on the incidence of hepatotoxicity in hospitalized Japanese patients.

METHODS

Thirty-nine patients were divided into 3 groups according to trough concentrations in two consecutive TDMs: <4 μg/ml in the first TDM (group A, n=25), >4 μg/ml in the first and <4 μg/ml in the second TDM (group B, n=8), and >4 μg/ml in both first and second TDMs (group C, n=6).

RESULTS

Incidences of hepatotoxicity in groups A, B and C were 16.0, 25.0 and 83.3%, and significant differences were observed between groups A and C and groups B and C. Multiple logistic regression analysis identified the classification into groups A, B and C as an independent variable of hepatotoxicity.

CONCLUSIONS

These results suggest that sustained high trough concentration of voriconazole may increase the risk of hepatotoxicity, and decreasing trough concentration to <4 μg/ml by dose adjustment after the initial TDM may reduce the incidence of hepatotoxicity in patients treated with voriconazole.

Bronchial stump aspergillosis after stapled lobectomy for lung cancer

Aspergillus causes several pulmonary complications, but bronchial stump aspergillosis (BSA) is very rare. To date, 31 cases of bronchial stump aspergillosis have been reported in the English, German, and Japanese literature. The bronchial stump was closed by hand-sewn suturing in most cases, but we report herein two cases of BSA that developed after stapled closure of the bronchial stump.

Is peak concentration needed in therapeutic drug monitoring of vancomycin? A pharmacokinetic-pharmacodynamic analysis in patients with methicillin-resistant staphylococcus aureus pneumonia

BACKGROUND

We analyzed the pharmacokinetic-pharmacodynamic relationship of vancomycin to determine the drug exposure parameters that correlate with the efficacy and nephrotoxicity of vancomycin in patients with methicillin-resistant Staphylococcus aureus pneumonia and evaluated the need to use peak concentration in therapeutic drug monitoring (TDM).

METHODS

Serum drug concentrations of 31 hospitalized patients treated with vancomycin for methicillin-resistant S. aureus pneumonia were collected.

RESULTS

Significant differences in trough concentration (Cmin)/minimum inhibitory concentration (MIC) and area under the serum concentration-time curve (AUC0-24)/MIC were observed between the response and non-response groups. Significant differences in Cmin and AUC0-24 were observed between the nephrotoxicity and non-nephrotoxicity groups. Receiver operating characteristic curves revealed high predictive values of Cmin/MIC and AUC0-24/MIC for efficacy and of Cmin and AUC0-24 for safety of vancomycin.

CONCLUSIONS

These results suggest little need to use peak concentration in vancomycin TDM because Cmin/MIC and Cmin are sufficient to predict the efficacy and safety of vancomycin.

Physicians' attitudes toward the definition of "death from age-related physical debility" in deceased elderly with aspiration pneumonia

AIM

Deaths from aspiration pneumonia in elderly patients are occasionally considered to be "death from age-related physical debility", because most aspiration pneumonias are a result of aging and lead to death without any definitive therapy. The aim of the present study was to assess physicians' attitudes toward the diagnosis of and actual description of "death from age-related physical debility" on death certificates for deceased patients with aspiration pneumonia.

METHODS

This study surveyed 62 Japanese physicians including 36 pulmonologists and 26 other physicians who treat patients with pneumonia. Their attitudes regarding consideration and actually recorded "death from age-related physical debility" for deceased patients with aspiration pneumonia were assessed by using anonymous questionnaires, which included the decision-making process and the necessity of detailed diagnostic criteria.

RESULTS

A total of 32 (52%) respondents had considered deceased patients with aspiration pneumonia to be "death from age-related physical debility", and 10 (16%) have actually stated this on the death certificate. Advanced age, bedridden status, inability of oral intake and disturbance of consciousness including dementia were major factors in their decision-making. A total of 34 (55%) of the respondent physicians wanted detailed criteria to be established.

CONCLUSIONS

Physicians' attitudes toward the definition of "death from age-related physical debility" vary a great deal depending on the respondent. The description in death certificates therefore might inaccurately reflect the results of current mortality statistics in Japan.

Thin-section CT findings in Pseudomonas aeruginosa pulmonary infection

OBJECTIVE

The aim of this study was to assess clinical and pulmonary thin-section CT findings in patients with acute Pseudomonas aeruginosa (PA) pulmonary infection.

METHODS

We retrospectively identified 44 patients with acute PA pneumonia who had undergone chest thin-section CT examinations between January 2004 and December 2010. We excluded nine patients with concurrent infections. The final study group comprised 35 patients (21 males, 14 females; age range 30-89 years, mean age 66.9 years) with PA pneumonia. The patients' clinical findings were assessed. Parenchymal abnormalities, enlarged lymph nodes and pleural effusion were evaluated on thin-section CT.

RESULTS

Underlying diseases included malignancy (n=13), a smoking habit (n=11) and cardiac disease (n=8). CT scans of all patients revealed abnormal findings, including ground-glass opacity (n=34), bronchial wall thickening (n=31), consolidation (n=23) and cavities (n=5). Pleural effusion was found in 15 patients.

CONCLUSION

PA pulmonary infection was observed in patients with underlying diseases such as malignancy or a smoking habit. The CT findings in patients with PA consisted mainly of ground-glass attenuation and bronchial wall thickening.

ADVANCES IN KNOWLEDGE

The CT findings consisted mainly of ground-glass attenuation, bronchial wall thickening and cavities. These findings in patients with an underlying disease such as malignancy or a smoking habit may be suggestive of pneumonia caused by PA infection.

Cloning of the lanosterol 14-α-demethylase ( ERG11 ) gene in Trichosporon asahii: a possible association between G453R amino acid substitution and azole resistance in T. asahii

Lanosterol 14-α-demethylase ( Erg11 protein; Erg11p ), encoded by the ERG11 gene, is the primary target of azoles. Recently, a change in affinity of this enzyme for azoles has been reported as a resistance mechanism in several fungal species. Trichosporon asahii ( T. asahii) is susceptible to fluconazole (FLC). This report identified the ERG11 gene of T. asahii (NCBI accession; HQ176415). The Erg11p of T. asahii, presumed from the DNA sequence, was closely related to the Erg11p of Cryptococcus neoformans. Furthermore, a FLC-susceptible strain was cultured in medium containing FLC at concentrations from 4.0 to 16 μg mL(-1) in order to analyze the development of FLC resistance in T. asahii. The degree of resistance was related to the FLC concentration of the growth medium. One highly resistant strain that was cultured in the medium containing 16 μg mL(-1) FLC contained 1 point mutation (G1357C) that caused a single amino acid substitution at G453R. This amino acid is highly conserved among major fungal pathogens, and it is in a region very close to the heme-binding domain, which is characteristic of the cytochrome P450 superfamily, the primary target for the azole class of antifungal agents. This amino acid substitution may have caused the high resistance to azoles in T. asahii.

Inhibitory effect of statins on inflammatory cytokine production from human bronchial epithelial cells

Statins are 3-hydroxy-3-methylglutaryl-co-enzyme A reductase inhibitors of cholesterol biosynthesis, and have been reported to exert pleiotropic effects on cellular signalling and cellular functions involved in inflammation. Recent reports have demonstrated that previous statin therapy reduced the risk of pneumonia or increased survival in patients with community-acquired pneumonia. However, the precise mechanisms responsible for these effects are unclear. In the present study, we examined the effects of statins on cytokine production from lipopolysaccharide (LPS)-stimulated human bronchial epithelial cells (BEAS-2B). Interleukin (IL)-6 and IL-8 mRNA expression and protein secretion in LPS-stimulated cells were inhibited significantly by the lipophilic statin pitavastatin and the hydrophilic statin pravastatin. As these inhibitory effects of statin were negated by adding mevalonate, the anti-inflammatory effects of statins appear to be exerted via the mevalonic cascade. In addition, the activation levels of Ras homologue gene family A (RhoA) in BEAS-2B cells cultured with pitavastatin were significantly lower than those without the statin. These results suggest that statins have anti-inflammatory effects by reducing cytokine production through inhibition of the mevalonic cascade followed by RhoA activation in the lung.

[Current anti-influenza virus chemotherapy]

The environment surrounding influenza is changing in recent years. In the spring of 2009, pandemic (H1N1) 2009 occurred in Mexico, and became epidemic on a global scale thereafter. Therefore, control of influenza is very important all over the world. Now in Japan, four specific anti-influenza antiviral drugs are available: amantadine, oseltamivir, zanamivir and peramivir. Pandemic (H1N1) 2009 are amantadine-resistant viruses, thus is not recommended for use. Oseltamivir is most commonly used in Japan, however, we have to pay attention to oseltamivir-resistant influenza virus. Almost no zanamivir-resistant influenza virus has been so far reported. In Japan, peramivir is the first drip infusion medicine and is expected to be used in severe cases.