Development of selective medium for IMP-type carbapenemase-producing Enterobacteriaceae in stool specimens

Background

Identification of carbapenemase-producing Enterobacteriaceae (CPE) in faecal specimens is challenging. This fact is particularly critical because low-level carbapenem-resistant organisms such as IMP-producing CPE are most prevalent in Japan. We developed a modified selective medium more suitable for IMP-type CPE.

Methods

Fifteen reference CPE strains producing different types of β-lactamases were used to evaluate the commercially available CHROMagar KPC and chromID CARBA as well as the newly prepared MC-ECC medium (CHROMagar ECC supplemented with meropenem, cloxacillin, and ZnSO₄) and M-ECC medium (CHROMagar ECC supplemented with meropenem and ZnSO₄). A total of 1035 clinical samples were then examined to detect CPE using chromID CARBA and M-ECC medium.

Results

All tested strains producing NDM-, KPC-, and OXA-48-carbapenemases were successfully cultured in the media employed. Although most of the IMP-positive strains did not grow in CHROMagar KPC, chromID CARBA, or MC-ECC, all tested strains grew on M-ECC. When faecal samples were applied to the media, M-ECC medium allowed the best growth of IMP-type CPE with a significantly higher sensitivity (99.3%) than that of chromID CARBA (13.9%).

Conclusions

M-ECC medium was determined as the most favourable selective medium for the detection of IMP-type CPE as well as other types of CPE.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2312-1) contains supplementary material, which is available to authorized users.

Nosocomial transmission of carbapenem-resistant Klebsiella pneumoniae elucidated by single-nucleotide variation analysis: a case investigation

Identifying transmission route of antimicrobial-resistant pathogen is essential for appropriate infection control strategy in healthcare facilities. We report the utility of single-nucleotide variation analysis in tracing nosocomial transmission of antimicrobial-resistant pathogens by describing a pseudo-outbreak case of carbapenem-resistant Klebsiella pneumoniae. The present case highlights that infection control strategy should encompass pathological dissection rooms, neglected but potentially highly contaminated places in hospitals.

Infective thoracic aortic aneurysm caused by Clostridium difficile after endovascular aortic repair

Clostridium difficile generally causes enterocolitis by producing pathogenic toxins, while extraintestinal infections with C. difficile are extremely rare. Here we report the first documented case of an infective thoracic aortic aneurysm caused by nontoxic C. difficile that occurred after vascular interventions including endovascular aortic repair. The present case illustrates that endovascular interventions may expose patients to the rare infection by yielding the ischemic intestinal tract as an entry site for the pathogen into the bloodstream and providing an anaerobic environment inside the thrombosed aneurysm.

[The annual changes in antimicrobial susceptibility test results of Pseudomonas aeruginosa isolates from the Kinki district]

A study was conducted of the 1,225 Pseudomonas aeruginosa strains that were isolated at 20 medical institutions in the Kinki district between 2011 and 2013 to determine their antimicrobial susceptibility and to characterize the strains of multidrug-resistant Pseudomonas aeruginosa (MDRP) and the metallo-β-lactamase (MBL) -producing strains. The MIC50/MIC90 values (μg/mL) of the various antimicrobial agents were as follows: imipenem, 2/>8; meropenem, 1/>8; doripenem, 0.5/8; biapenem, 1/>8; tazobactam/piperacillin, 8/>64; piperacillin, 8/>64; sulbactam/cefoperazone, 8/64; cefepime, 4/16; cefozopran, 2/>16; aztreonam, 8/>16; amikacin, 4/16; levofloxacin, 1/>4; and ciprofloxacin, 0.25/>2. From the viewpoint of the annual changes in the susceptibility rates (according to the CLSI guidelines [M100-S22]), the susceptibility to tazobactam/piperacillin, piperacillin, cefepime, cefozopran and aztreonam decreased in 2013. On the other hand, two antimicrobial agents showed high susceptibility rates each year; amikacin (94.0-95.6%) showed the highest rate, followed by doripenem (80.3-82.6%). With the exception of amikacin, there were substantial inter-institutional differences in antimicrobial susceptibility. In comparison to the previous CLSI guidelines (M100-S21), the new CLSI guidelines (M100-S22) on the use of carbapenems and penicillins show that the MIC80 has been affected. The MDRP detection rates in 2011, 2012 and 2013 were 1.8% (8 strains), 1.8% (8 strains), and 2.8% (10 strains), respectively. The MBL detection rates were as follows: bla(VIM-2), 0.2% (1 strain) in 2011; bla(IMP-1), 0.9% (4 strains) in 2012, and 1.7% (6 strains, including bla(IMP-1) [3 strains], bla(IMP-2) [2 strains] and bla(VIM-2) [1 strain]) in 2013.

[The Role of the Microbiology Laboratory in Healthcare-Associated Infection Control]

Healthcare-associated infection control aims to protect patients and health care workers from infections. For successful control, it is important not to transmit pathogens and resistant bacteria as well as not to create new resistant bacteria. Preventing the transmission of pathogens and resistant bacteria involves the reliable implementation of preventative measures for specific pathways in response to the causative microorganism. Appropriate information from the microbiology laboratory promotes the thorough implementation of prevention measures. This laboratory also makes it possible to promptly understand data on infections for the whole hospital. Therefore, in addition to the normal reporting of results, surveillance reports of infectious agents, such as drug-resistant bacteria, acid-fast bacilli smear-positive patients, and influenza virus antigen-positive patients must be immediately reported to the infection control team (ICT), which is the unit responsible for infection control. In addition, it is important to provide information on the detection of resistant bacteria and antimicrobial susceptibility rates to clinical staff and promote the development of systems in which new resistant bacteria are not created.

A Chronic Respiratory Pasteurella multocida Infection Is Well-Controlled by Long-Term Macrolide Therapy

A 57-year-old woman with severe bronchiectasis frequently received antibiotics, including penicillin, for acute exacerbations due to Pasteurella multocida. Although the bacteria showed a decrease in antibiotic susceptibility, her symptoms and X-ray findings became stable, and severe exacerbations were not observed for the last few years after a low-dose erythromycin treatment was started. The development of a respiratory infection with Pasteurella multocida is relatively uncommon, but it can be controlled by immunomodulation which is associated with long-term macrolide therapy.

Capnocytophaga ochracea-related Bacterium Bacteremia in a Hypertrophic Cardiomyopathy Patient without Neutropenia

Gram-negative fusiform rods were detected in a blood culture obtained from a 63-year-old man who had been hospitalized for a long duration for severe heart failure. Although the organism could not be identified using a conventional method, it was finally identified as a bacterium of the Capnocytophaga ochracea group based on the results of biochemical testing, 16S rRNA sequencing and a matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis. Although neutropenic patients with poor oral hygiene are exclusively vulnerable to Capnocytophaga bacteremia, this case was unique because such predisposing conditions were not noted. A multi-centered investigation is warranted for a better understanding of this clinically rare, but potentially pathogenic organism.

Validation of a phage-open reading frame typing kit for rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) transmission in a tertiary hospital

Surveillance is very important to prevent the nosocomial spread of methicillin-resistant Staphylococcus aureus (MRSA), and infection sources and routes have historically been identified using molecular and epidemiological genotyping with pulsed-field gel electrophoresis. However, phage-open reading frame typing (POT) has recently been developed. Here, we investigated whether POT would be useful to survey MRSA outbreaks and transmission. We therefore applied POT to 91 MRSA isolates detected in cultures from inpatients at our hospital between May and October 2014. Among the 91 isolates, 12 POT types comprising 38 isolated MRSA strains were considered as overlapping. Five of them were detected in different wards, whereas the remaining seven were found in the same ward, including the emergency department. Three of seven POT number 93-155-111 strains were detected in the surgical ward, and all of four POT number 93-157-61 strains were detected in the cardiosurgical ward. These data suggested that transmission of the MRSA strains with the same POT-types from the same wards was nosocomial, and that POT accurately and rapidly identified MRSA strains, which allowed effective control of infection and transmission.

Invasive pulmonary aspergillosis due to Aspergillus lentulus: Successful treatment of a liver transplant patient

We report a patient with severe invasive pulmonary fungal infection caused by Aspergilllus lentulus, which was identified by genetic analysis, following liver transplantation. The patient was initially suspected to have Aspergilllus fumigatus infection, but worsened clinically despite antifungal therapy appropriate for that species. The patient survived after accurate diagnosis, and detailed drug susceptibility testing led to adequate therapy, demonstrating the importance of performing these investigations for severely immunocompromised patients, including organ transplant recipients.

Anisotropy of the superconducting gap in the iron-based superconductor BaFe2(As(1-x)P(x))2

We report peculiar momentum-dependent anisotropy in the superconducting gap observed by angle-resolved photoemission spectroscopy in BaFe₂(As_1-xP_x)₂ (x = 0.30, T_c = 30 K). Strongly anisotropic gap has been found only in the electron Fermi surface while the gap on the entire hole Fermi surfaces are nearly isotropic. These results are inconsistent with horizontal nodes but are consistent with modified s_± gap with nodal loops. We have shown that the complicated gap modulation can be theoretically reproduced by considering both spin and orbital fluctuations.

Dependence of carrier doping on the impurity potential in transition-metal-substituted FeAs-based superconductors

In order to examine to what extent the rigid-band-like electron doping scenario is applicable to the transition metal-substituted Fe-based superconductors, we have performed angle-resolved photoemission spectroscopy studies of Ba(Fe(1-x)Ni(x))(2)As(2) (Ni-122) and Ba(Fe(1-x)Cu(x))(2)As(2) (Cu-122), and compared the results with Ba(Fe(1-x)Co(x))(2)As(2) (Co-122). We find that Ni 3d-derived features are formed below the Fe 3d band and that Cu 3d-derived ones further below it. The electron and hole Fermi surface (FS) volumes are found to increase and decrease with substitution, respectively, qualitatively consistent with the rigid-band model. However, the total extra electron number estimated from the FS volumes (the total electron FS volume minus the total hole FS volume) is found to decrease in going from Co-, Ni-, to Cu-122 for a fixed nominal extra electron number, that is, the number of electrons that participate in the formation of FS decreases with increasing impurity potential. We find that the Néel temperature T(N) and the critical temperature T(c) maximum are determined by the FS volumes rather than the nominal extra electron concentration or the substituted atom concentration.

Reliable and reproducible method for rapid identification of Nocardia species by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been challenged for the identification of Nocardia species. However, the standard ethanol-formic acid extraction alone is insufficient in allowing the membrane proteins of Nocardia species to be ionized by the matrix. We therefore aimed to establish our new extraction method for the MALDI-TOF MS-based identification of Nocardia species isolates. Our modified extraction procedure is through dissociation in 0.5% Tween-20 followed by bacterial heat-inactivation, mechanical breaking of the cell wall by acid-washed glass beads and protein extraction with formic acid and acetonitrile. As reference methods for species identification, full-length 16S rRNA gene sequencing and some phenotypical tests were used. In a first step, we made our own Nocardia database by analyzing 13 strains (13 different species including N. elegans, N. otitidiscaviarum, N. asiatica, N. abscessus, N. brasiliensis, N. thailandica, N. farcinica, N. nova, N. mikamii, N. cyriacigeorgica, N. asteroids, Nocardiopsis alba, and Micromonospora sp.) and registered to the MALDI BioTyper database. Then we established our database. The analysis of 12 challenge strains using the our database gave a 100% correct identification, including 8 strains identified to the species level and 4 strains to the genus level (N. elegans, N. nova, N. farcinica, Micromonospora sp.) according to the manufacture's log score specifications. In the estimation of reproducibility of our method intended for 4 strains, both within-run and between-run reproducibility were excellent. These data indicates that our method for rapid identification of Nocardia species is with reliability, reproducibility and cost effective.

Epidemiology of Escherichia coli, Klebsiella species, and Proteus mirabilis strains producing extended-spectrum β-lactamases from clinical samples in the Kinki Region of Japan

In the present study, nonduplicate, clinical isolates of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, Klebsiella spp, and Proteus mirabilis were collected during a 10-year period from 2000 to 2009 at several hospitals in the Kinki region, Japan. The detection rate of E coli markedly increased from 0.24% to 7.25%. The detection rate of Klebsiella pneumoniae increased from 0% to 2.44% and that of P mirabilis from 6.97% to 12.85%. The most frequently detected genotypes were the CTX-M9 group for E coli, the CTX-M2 group for K pneumoniae, and the CTX-M2 group for P mirabilis. E coli clone O25:H4-ST131 producing CTX-M-15, which is spreading worldwide, was first detected in 2007. The most common replicon type of E coli was the IncF type, particularly FIB, detected in 466 strains (69.7%). Of the K pneumoniae strains, 47 (55.3%) were of the IncN type; 77 P mirabilis strains (96.3%) were of the IncT type. In the future, the surveillance of various resistant bacteria, mainly ESBL-producing Enterobacteriaceae, should be expanded to prevent their spread.

[Surveillance of antimicrobial activity of Pseudomonas aeruginosa isolated in the Kinki district]

The antimicrobial activity of 18 antimicrobial agents were measured for the 500 Pseudomonas aeruginosa strains that had been isolated from various clinical specimens in 17 medical institutions in the Kinki district from April to July of 2008. The antimicrobial activity was excellent in the order of tobramycin (TOB), arbekacin (ABK), doripenem (DRPM), gentamicin (GM) and amikacin (AMK). Susceptible rate that was interpreted by Clinical and Laboratory Standards Institute (CLSI) was high in the order of AMK, TOB, tazobactam/piperacillin (TAZ/PIPC), DRPM, ABK. Also, the difference in susceptible rate was observed between departments, materials and institutions. Multidrug resistant strains were only 12 (2.4%) but strains that had resistance to 2 agents were 48 (9.6%), therefore, implementation of further surveillance should be continued.

Effects of exercise training in patients with chronic heart failure and advanced left ventricular systolic dysfunction receiving β-blockers

BACKGROUND

It remains unclear whether patients with chronic heart failure (CHF) and advanced left ventricular (LV) dysfunction on β-blocker therapy benefit from exercise training (ET).

METHODS AND RESULTS

We studied 45 CHF patients with advanced LV dysfunction [ejection fraction (LVEF) < 25%] and impaired exercise tolerance [normalized peak oxygen uptake (PVO₂) < 70%] receiving a β-blocker: 33 patients participated in a cardiac rehabilitation program with ET (ET group) and 12 did not (inactive control group). Exercise capacity, LV dimension and plasma B-type natriuretic peptide (BNP) were assessed before and after a 3-month study period. At baseline, both groups had markedly reduced LVEF (ET group 18 ± 4% vs. Control group 18 ± 5%, NS) and impaired exercise capacity (normalized PVO₂ 51 ± 10% vs. 55 ± 9%, NS). Although one patient in the ET group withdrew from the program due to worsening CHF, no serious cardiac events occurred during the ET sessions. After 3 months, the ET group (n = 24) had significantly improved PVO₂ by 16 ± 15% (1,005 ± 295 to 1,167 ± 397ml/min, P < 0.001), while the PVO₂ of the control group was unchanged. LV end-diastolic dimension decreased in both groups to a similar extent, but plasma BNP was significantly decreased only in the ET group (432 to 214 pg/ml, P < 0.05).

CONCLUSIONS

The data indicate that in CHF patients with advanced LV dysfunction on β-blocker therapy, ET successfully improves exercise capacity and BNP without adversely affecting LV remodeling or causing serious cardiac complications.

Two-dimensional and three-dimensional Fermi surfaces of superconducting BaFe2(As(1-x)P(x))2 and their nesting properties revealed by angle-resolved photoemission spectroscopy

We have studied the three-dimensional shapes of the Fermi surfaces (FSs) of BaFe(2)(As(1-x)P(x))(2) (x=0.38), where superconductivity is induced by isovalent P substitution and by angle-resolved photoemission spectroscopy. Moderately strong electron mass enhancement has been identified for both the electron and hole FSs. Among two observed hole FSs, the nearly two-dimensional one shows good nesting with the outer two-dimensional electron FS, but its orbital character is different from the outer electron FS. The three-dimensional hole FS shows poor nesting with the electron FSs. The present results suggest that the three dimensionality and the difference in the orbital character weaken FS nesting while partial nesting among the outer electron FSs of d(xy) character and/or that within the three-dimensional hole FS becomes dominant, which may lead to the nodal superconductivity.

Are Cardiac Events During Exercise Therapy for Heart Failure Predictable From the Baseline Variables?

BACKGROUND

Exercise training (ET) is an emerging therapy for chronic heart failure, but the baseline patient characteristics for predicting cardiac events (CEs) during the course of ET remain unknown.

METHODS AND RESULTS

Of the 111 stable heart failure patients who participated in a 3-month ET program, 6 withdrew from the program for cardiac reasons and 9 had transient interruptions in the program because of CEs. The baseline clinical characteristics of these 15 patients (CE group) and the remaining 96 patients (No-CE group) were compared. Compared with the No-CE group, the CE group had a significantly higher prevalence of pacemaker/implantable cardioverter-defibrillators, larger left ventricular end-diastolic diameter (LVEDDs), lower peak oxygen uptake, greater ventilation drive, and higher plasma brain natriuretic peptide concentration at baseline. Multivariate logistic regression analysis showed that a larger LVEDD was a significant predictor of the occurrence of a transient interruption to or permanent withdrawal from the ET program because of CEs. Receiver operating characteristic curve analysis demonstrated that an LVEDD > or = 65 mm had a sensitivity of 93% and specificity of 48% in predicting CEs.

CONCLUSIONS

Patients with a large LVEDD (> or = 65 mm) at baseline should be monitored carefully during the course of an ET program.

Usefulness of Immunological Detection of Both Toxin A and Toxin B in Stool Samples for Rapid Diagnosis of Clostridium difficile-associated Diarrhea

Toxin detection from stool specimens is critical for the diagnosis of Clostridium difficile-associated diarrhea (CDAD). In Japan, only two toxin detection kits targeting toxin A alone are commercially available. We evaluated ImmunoCard Toxin A & B (ImmunoCard), based on enzyme immunoassay for the rapid detection of both C. difficile toxins A and B in stool specimens, compared to a toxin A detection kit (Uniquick) and cytotoxin assay. C. difficile was also cultured from stool specimens and the toxin production type of C. difficile isolates was identified by PCR analysis. Compared to cytotoxin assay, ImmunoCard sensitivity was 86.2%, specificity 93.8%, positive predictive value 91.8%, and negative predictive value 89.4% (n = 146). Sensitivity was significantly higher than that of Uniquick (60.0%, p = 0.0016). ImmunoCard detected 90.6% of cytotoxin positive specimens with isolated toxin A-positive, toxin B-positive C. difficile strains (Uniquick; 67.9%, p = 0.008) and 70.0% of these with isolated toxin A-negative, toxin B-positive C. difficile strains. Although ImmunoCard was slightly less sensitive than cytotoxin assay, it requires no special equipment and completes the entire test in up to 20 min. ImmunoCard thus appears very useful in the rapid diagnosis of CDAD in the clinical laboratory. Kits for the detection of both C. difficile toxins A and B should be immediately introduced into Japan to ensure the correct diagnosis of CDAD and infection control.

Addition of spironolactone to an angiotensin-converting enzyme inhibitor decreases lung congestion and edema in Dahl hypertensive rats

We investigated the effect of adding spironolactone to treatment with an angiotensin-converting enzyme (ACE) inhibitor, imidapril, in Dahl salt-sensitive (DS) hypertensive heart failure rats with preserved systolic function. Male DS rats were fed laboratory chow containing 8% NaCl from 7 weeks of age. Rats were divided into four groups and treated for 9 weeks with vehicle alone (water; n = 23), the ACE inhibitor imidapril (1 mg kg(-1) day(-1); n = 16), spironolactone (2 mg kg(-1) day(-1); n = 15), or a combination of imidapril and spironolactone at the doses above (n = 16). The left ventricular weight to body weight (BW) ratio was significantly lower in the imidapril group (3.28 +/- 0.30 mg g(-1)) and the combination group (3.34 +/- 0.38 mg g(-1)) than in the vehicle group (3.71 +/- 0.46 mg g(-1)). Adding spironolactone to imidapril inhibited an increase in the ratio of lung weight to BW (4.38 +/- 0.50 mg g(-1)) related to high salt intake, while monotherapy (imidapril group, 4.61 +/- 0.90 mg g(-1); spironolactone group, 5.40 +/- 2.50) did not significantly change the ratio from that seen with vehicle treatment (6.32 +/- 3.62 mg g(-1)). All active treatments (imidapril, 0.66% +/- 0.67%; spironolactone, 0.51% +/- 0.55%; both together, 0.31% +/- 0.26%) inhibited a salt-intake related increase in the percentage area representing fibrous tissue compared with vehicle treatment alone (1.81% +/- 1.51%). These findings suggest that adding spironolactone to an ACE inhibitor is more effective in improving pulmonary congestion and edema in hypertensive heart failure with preserved systolic function than an ACE inhibitor alone.

B-type natriuretic peptide strongly reflects diastolic wall stress in patients with chronic heart failure: comparison between systolic and diastolic heart failure

OBJECTIVES

We explored the stimulus for B-type natriuretic peptide (BNP) secretion in the clinical setting of heart failure (HF).

BACKGROUND

Increasingly, plasma BNP levels are being incorporated into the clinical assessment and management of systolic heart failure (SHF) as well as diastolic heart failure (DHF). However, heterogeneity in BNP levels among individuals with HF can cause some confusion in interpreting results.

METHODS

In 160 consecutive patients presenting with HF, we measured plasma BNP levels and performed echocardiography and cardiac catheterization. Systolic and diastolic meridional wall stress was calculated from echocardiographic and hemodynamic data.

RESULTS

Although plasma BNP had a significant correlation (r2 = 0.296 [p < 0.001]) with left ventricular end-diastolic pressure (EDP) as previously reported, the correlation between plasma BNP and end-diastolic wall stress (EDWS) (r2 = 0.887 [p < 0.001]) was more robust. In a subanalysis of 62 patients with DHF, a similar result was obtained (r2 = 0.143 for EDP and r2 = 0.704 for EDWS). In a comparison between SHF and DHF, the BNP level was significantly higher in SHF (p < 0.001). Although EDP did not show any difference, EDWS was significantly higher in SHF than in DHF (p < 0.001).

CONCLUSIONS

The present study shows that plasma BNP levels reflect left ventricular EDWS more than any other parameter previously reported, not only in patients with SHF, but also in patients with DHF. The relationship of left ventricular EDWS to plasma BNP may provide a better fundamental understanding of the interindividual heterogeneity in BNP levels and their clinical utility in the diagnosis and management of HF.

Characteristics of Pseudomonas corneal infection related to orthokeratology

PURPOSE

To describe a Pseudomonas aeruginosa corneal infection resulting from orthokeratology.

METHODS

Case report.

RESULTS

A 17-year-old boy wearing orthokeratology (OK) lenses was referred to our clinic because of redness in his right eye in spite of his usage of ofloxacin (OFLX) eye drops. An excavated paracentral corneal ulcer with an immune ring and hypopyon was observed. It was positioned under the paracentral steeper portion of the optic of the OK lens. Culture of the lens solution revealed P. aeruginosa. The patient was treated with topical OFLX and cefmenoxime (CMX) plus intravenous and subconjunctival injections of cefozopran (CZOP), successfully. The antibiotic susceptibility of P. aeruginosa by the disk diffusion susceptibility test was reduced under moderately hypoxic conditions. Glycocalyx slime was formed on the OK lens in vitro by P. aeruginosa isolated from the case.

CONCLUSIONS

Changes in P. aeruginosa susceptibility to antibiotics under moderately hypoxic conditions and glycocalyx slime formation might affect the features of OK lens-associated infections.

[Surveillance of antimicrobial resistance of Streptococcus pneumoniae isolates from the Kinki Region of Japan during 2003/2004. The Surveillance Program of Bacterial Resistance in the Kinki Region of Japan; SBRK]

Three hundred seventy five isolates of Streptococcus pneumoniae were collected from 14 medical institutions in the Kinki region of Japan between November 2003 and February 2004. We determined the minimum inhibitory concentration (MIC) of penicillin G (PCG) and 25 of other antimicrobial agents against these isolates according to the National Committee for Clinical Laboratory Standards (NCCLS). Overall, 71.5% of all isolates were resistant to PCG (intermediate and resistant categories were 51.7% and 19.8%, respectively). For the carbapenems and penem, the rank order of activity was PAPM (MIC90, 0.12 microg/ml) > IPM (0.25 microg/ml) > MEPM (0.5 microg/ml) = FRPM (0.5 microg/ml). For the cephems, the overall rank order of activity was CPR (MIC90, 0.5 microg/ml) = CDTR (0.5 microg/ml) > CTRX (1 microg/ml) = CTX (1 microg/ml) = CZOP (1 microg/ml) = CFPN (1 microg/ml). Rank order activity for six of fluoroquinolones was TFLX = MFLX (MIC90, 0.25 microg/ml) > GFLX (0.5 microg/ ml) = SPFX (0.5 microg/ml) > LVFX (1 microg/ml) > PZFX (4 microg/ml). The rate of resistance to fluoroquinolones per the NCCLS criteria were very low, ranging from 0.7% to 2.6%. Rate of resistance to other antimicrobiotics were CAM, 77.0%; CLDM, 41.7%; TEL, 0%; VCM, 0%; ST, 32.7%, and CP, 21.4%.

A Case of Sinus of Valsalva-right Ventricle Fistula Without a Typical Aneurysm, and a Single Origin of the Coronary Arteries

Few previous reports have described a sinus of Valsalva fistula without an aneurysm in Japanese patients. A single origin of the coronary arteries is a rare coronary anomaly. We describe a 75-year-old woman with a single origin of the coronary arteries and a sinus of Valsalva fistula without a typical aneurysm. Echocardiography showed turbulent flow from the right coronary sinus of Valsalva to the right ventricle throughout the cardiac cycle. Aortography confirmed the presence of a right coronary sinus of Valsalva-right ventricle shunt jet. Echocardiography and aortography demonstrated that there was no deformity of the sinus of Valsalva. Cardiac catheterization revealed that the left-to-right shunt rate was 29% and the Qp/Qs was 1.41. Aortography and coronary angiography did not identify a right coronary artery originating from the right sinus of Valsalva. Coronary angiography revealed that the right coronary artery arose from the proximal part of the left anterior descending artery and did not detect significant organic stenosis of the coronary artery. She was diagnosed as having a sinus of Valsalva to right ventricle fistula without an aneurysm, and a single origin of the coronary arteries.

Angiotensin-Converting Enzyme Genotype is Not Associated With Exercise Capacity or the Training Effect of Cardiac Rehabilitation in Patients After Acute Myocardial Infarction

BACKGROUND

The relationship of the genotype for the angiotensin-converting enzyme (ACE) with exercise capacity or training effects has been studied in athletes or healthy persons, but recently the ACE DD genotype was reported to be associated with decreased exercise capacity in patients with congestive heart failure. Therefore, in the present study the association between the ACE genotype and exercise capacity was investigated in patients with acute myocardial infarction (AMI) participating in cardiac rehabilitation (CR) for 3 months.

METHODS AND RESULTS

The study population comprised 168 patients stratified as II (n=75), ID (n=67), and DD (n=26) according to ACE genotype. Baseline left ventricular ejection fraction (LVEF) was similar among the genotype groups. In all patients, exercise capacity (peak work rate (PWR) and peak oxygen uptake (PVO 2)) significantly increased after CR. However, no differences were observed in PWR and PVO2 among the genotype groups at baseline or after CR. The results were similar even when analyzed in 60 patients with left ventricular (LV) dysfunction (LVEF <45%).

CONCLUSION

The present study suggests that there is no association between ACE I/D polymorphism and exercise capacity in patients after AMI, even with LV dysfunction. Furthermore, ACE genotype may have no influence on the effects of CR after AMI.

Severe Chlamydophila psittaci pneumonia rapidly diagnosed by detection of antigen in sputum with an immunochromatography assay

We report a case of severe Chlamydophila (Chlamydia) psittaci pneumonia rapidly diagnosed by detection of antigen in sputum with an immunochromatography assay. The patient was admitted to our hospital because of shock, disturbance of consciousness, accidental hypothermia, and multiple organ dysfunction syndrome, and he recovered after administration of intravenous erythromycin and high-dose methylpredonisolone therapy. Psittacosis was confirmed by detection of 16S rRNA gene of C. psittasi in sputum with multiplex-polymerase chain reaction analysis. Serological responses to C. psittasi, C. trachomatis, and C. pneumoniae were also evaluated, and serological cross-reactivity was observed between each species. We consider that the commercially available immunochromatography assay for Chlamydia species can be helpful for rapid diagnosis of Chlamydia infection of the respiratory tract. Hereafter, further examination will be necessary regarding pretreatment of specimens or detection sensitivity and specificity.

Seroprevalence survey of measles, rubella, varicella, and mumps antibodies in health care workers and evaluation of a vaccination program in a tertiary care hospital in Japan

Vaccine-preventable viral infections in health care workers (HCWs) have been on the rise for the past 10 years in Japan. To reduce the viral infections and the burden of exposure follow-up surveys at a tertiary care hospital in Osaka, Japan, a seroprevalence survey was conducted, and free vaccinations for measles, rubella, varicella, and mumps were offered to newly hired HCWs (199 physicians and 72 nurses and nursing assistants) who had negative serologic results for antibodies against these viruses. Negative antibody titers were obtained from 7.4% of the newly hired HCWs for measles, 12.5% for rubella, 4.1% for varicella, and 15.9% for mumps. The vaccination program for HCWs improved the vaccine-preventable infection rates and resulted in fewer exposure follow-up surveys, fewer lost work days, and fewer HCWs requiring hospitalization for these viral infections compared with those counted for the previous year. These data indicate that all HCWs should be strongly recommended to be vaccinated against (or have documented immunity to) these viruses in Japan, as is the case in the United States.

In vitro combined effects of cefozopran/teicoplanin and cefozopran/vancomycin on methicillin-resistant Staphylococcus aureus

We determined the in vitro effects of teicoplanin (TEIC) or vancomycin (VCM) added to cefozopran (CZOP) on 50 methicillin-resistant Staphylococcus aureus (MRSA) strains, using a modified checkerboard method with serial 1.25-fold dilutions, and assessed the time-kill curve. CZOP + TEIC was synergistic (fractional inhibitory concentration index < or = 0.5) against 98% and CZOP + VCM against 20% of strains. Both drug combinations were additive against the remaining strains. A comparison of the fractional bactericidal concentration indices for 32 strains showed synergistic bactericidal effects for CZOP + TEIC in 88%, and in 48% for CZOP +VCM, confirming that CZOP + TEIC is superior to CZOP + VCM. The time-kill curve confirms that the bactericidal potency of these drugs is increased through combined use with CZOP. These results suggest that treatment using TEIC or VCM with CZOP may be useful in treating MRSA infections, including polymicrobial infections and those involving Gram-negative rods.

Pseudomembranous colitis caused by toxin A-negative/toxin B-positive variant strain of Clostridium difficile

We report the first case of pseudomembranous colitis (PMC) due to a toxin A-negative, toxin B-positive strain (toxin A variant strain) of Clostridium difficile in Japan. The toxin A variant strain of C. difficile is capable of causing PMC and is undetectable in clinical laboratories that use only toxin A immunoassays for C. difficile testing. If C. difficile-associated diarrhea is clinically suspected and toxin A is not detected, then the possibility of a toxin A variant strain should be considered, and further diagnostic testing, such as polymerase chain reaction (PCR) analysis for the detection of C. difficile toxin genes should be performed.

[Cytomegalovirus infection]

By application of PCR technology, Cytomegalovirus(CMV) DNA can be detected from clinical specimens, rapidly and with high sensitivity. PCR-based assays can detect CMV DNA from blood even prior to the onset of clinical symptoms, so qualitative PCR assays are used as an indicator for preemptive therapy in transplant recipients. But it is not always helpful in CMV infection because it cannot distinguish latent from active infection, meaning lower positive predictive value for clinical disease. In recent years, quantitative PCR assays are increasingly being utilized in the clinical setting to (i) identify individuals at risk of developing CMV disease(determination of clinical threshold), (ii) monitor viral response to antiviral treatment, (iii) predict individuals at risk of clinical relapse, and (iv) serve as an early indicator of antiviral resistance.

Accuracy of flow and sensors of indirect calorimetry for neonates and infants: using mass spectrometry and a pneumotachogram

1. The accuracy of measurements of flow rate and concentrations of O2 and CO2 in expiratory gas by indirect calorimetry (IC) using paediatric and adult circuits were assessed by mass spectrometry and a pneumotachogram, which have been proven as the most reliable instruments for these purposes. 2. In the paediatric circuit, all measurements were demonstrated to be reliable: error rates for flow rate, O2 concentration and CO2 concentration were +3.13, +2.66 and -6.63%, respectively. All were within the 10%, which is acceptable as a biological error. 3. However, in the adult circuit of IC, all measurements were reliable except for measurements of CO2 concentration: error rates for flow rate, O2 concentration and CO2 concentration were +2.82, +1.64 and +11.42%, respectively. 4. A fluctuation phenomenon of expiratory gas concentration was observed only in IC. Mass spectrometry did not show this phenomenon. This phenomenon seems to be derived from the IC machine itself.

Peripartum cardiomyopathy and biventricular thrombi

Peripartum cardiomyopathy is a rare cardiac disorder characterized by the development of heart failure in the last month of pregnancy or up to 5 months postpartum in women without other determinable causes of cardiac failure. Intracardiac thrombi have been found at autopsy in some patients with this condition and have been demonstrated in the left or right ventricles on 2-dimensional echocardiography. A 23-year-old woman presented with peripartum cardiomyopathy and biventricular thrombi on echocardiography. The thrombi were spherical, pedunculate, shaggy and irregular in configuration, and freely mobile, suggesting that they were fresh. She was treated with conventional heart failure therapy and anticoagulants. Four days later, the apical thrombi within both ventricles had disappeared and there was no evidence of embolism on physical examination. The hypercoagulable state of the peripartum period and the severe biventricular dysfunction most likely led to the formation of biventricular thrombi.

Effects of anti-vasospastic agents in Japanese patients with dilated cardiomyopathy and coronary vasospasm

The pathogenesis of dilated cardiomyopathy (DCM) is unknown, but clinical evidence suggests that coronary vasospasm is associated with the development of DCM in some cases. In the present study, we aimed to clarify the prevalence of coronary vasospasm in patients with DCM, the characteristics of patients with DCM and coronary vasospasm, and the effects of anti-vasospastic agents on patients with DCM and coronary vasospasm. This study included 18 consecutive patients with DCM who underwent cardiac catheterization with ergonovine provocation testing. The patient was diagnosed as having coronary vasospasm if ergonovine induced coronary vasoconstriction > or = 75% diameter narrowing was observed compared to the diameter after nitroglycerin administration. Six (33%) patients were found to have coronary vasospasm and anti-vasospastic agents were added after the cardiac catheterization. The prevalence of atrial fibrillation in the patients with DCM and coronary vasospasm was greater than that in DCM without coronary vasospasm [67% vs 8% (P<0.05)]. The left ventricular end-diastolic dimension decreased from 61 mm (56/64) to 55 mm (53/56) (median, 25th/75th percentile, P<0.05) and the left ventricular ejection fraction increased from 36% (32/40) to 47% (46/48) (median, 25th/ 75th percentile, P<0.05) after the administration of anti-vasospastic agents and 4 of the 6 patients improved symptomatically. Therefore, ergonovine provocation testing is useful in identifying patients with DCM and coronary vasospasm, in whom cardiac performance is expected to be improved with anti-vasospastic agent therapy. DCM patients with atrial fibrillation may be a clue for identifying patients with coronary vasospasm.

Using isoproterenol stress echocardiography to predict the response to carvedilol in patients with dilated cardiomyopathy

Trials have demonstrated that carvedilol can produce hemodynamic, symptomatic, and prognostic improvements in dilated cardiomyopathy (DCM), but some DCM patients have deteriorated after carvedilol, developing congestive heart failure. The present study investigated the use of isoproterenol (ISP) stress echocardiography to select those patients with DCM who would respond to carvedilol. ISP was infused intravenously in 22 patients with DCM and they were classified into 2 groups based on the left ventricular systolic response: good response to ISP [change in fractional shortening (FS) with ISP > 0.05, n=13] and poor response to ISP (change < or = 0.05, n=9). In the good response group, FS significantly increased from 0.12+/-0.04 to 0.17+/-0.08 (mean+/-SD, p<0.05) with carvedilol, and 7 patients improved symptomatically (New York Heart Association class). However, in the poor response group, no significant difference was observed between FS at baseline and that at the end of follow-up. Moreover, only 1 patient in the poor response group improved symptomatically. ISP stress echocardiography can assist in selecting patients with DCM who will respond positively to carvedilol.

[Informed consent for the use of the remaining portion of laboratory specimens for education, research, and quality control of laboratory tests]

The remaining portion of a laboratory specimen is usually used for education, research, and quality control of laboratory tests in hospitals, but informed consent has not been obtained because of the high volume of patients who undergo laboratory tests. However, patients must be informed in some manner. Therefore, we decided to inform patients that any remaining specimen would be used for various purposes by placing such a notice on walls in the central clinical laboratory and hospital lobby. We then obtained a signature on a dissent document, instead of a consent document, from any patient who dissented from such use. This indirect process for obtaining informed consent was approved by the ethics committee of Osaka University Medical School. The number of dissent documents sent in to the director was 54 of about 400,000 patients who underwent laboratory tests over the last 3 years, and there was no complaint against this "informed consent process".

Neonatal presentation of adult-onset type II citrullinemia

Adult-onset type II citrullinemia (CTLN2) is characterized by a liver-specific argininosuccinate synthetase deficiency caused by a deficiency of the citrin protein encoded by the SLC25A13 gene. Until now, however, no SLC25A13 mutations have been reported in children with liver diseases. We described three infants who presented as neonates with intrahepatic cholestasis associated with hypermethioninemia or hypergalactosemia detected by neonatal mass screening. DNA analyses of SLC25A13 revealed that one patient was a compound heterozygote for the 851de14 and IVS11+IG-->A mutations and two patients (siblings) were homozygotes for the IVS11+lG-->A mutation. These results suggested that there may be a variety of liver diseases related to CTLN2 in children.