Rifamycin resistance, rpoB gene mutation and clinical outcomes of Staphylococcus species isolates from prosthetic joint infections in Republic of Korea.

OBJECTIVES: We conducted an in vitro investigation of the activity of rifamycins against planktonic and biofilm states of Staphylococcus aureus and Staphylococcus epidermidis isolates from patients with prosthetic joint infections (PJIs), characterised their rpoB gene mutations, and analysed the clinical outcomes of rifampicin-resistant isolates. METHODS: A total of 110 staphylococcal isolates were collected from patients with PJI. Antimicrobials tested using the broth microdilution method included rifampicin, rifabutin, rifapentine and rifaximin. We evaluated rpoB gene mutations to identify rifampicin resistance mechanisms. Clinical outcomes were assessed in rifampicin-resistant isolates. RESULTS: The 110 staphylococcal isolates included 85 S. aureus (55% methicillin-resistant) and 25 S. epidermidis (100% methicillin-resistant). Seven S. aureus isolates and two S. epidermidis isolates were resistant to rifampicin [minimum inhibitory concentration (MIC) ≥2 µg/mL] and these isolates exhibited rpoB gene mutations. Among the 78 rifampicin-susceptible S. aureus isolates and 23 S. epidermidis isolates, 76 S. aureus isolates (97.4%) and all S. epidermidis isolates (100%) were highly susceptible (MIC ≤ 0.06 µg/mL) to other rifamycins. The minimum biofilm bactericidal concentrations for ≥50% of isolates (MBBC50) to rifampicin, rifabutin, rifapentine and rifaximin were 4, 1, 2 and 4 µg/mL for S. aureus and 1, 0.125, 0.25 and 0.5 µg/mL for S. epidermidis, respectively, among rifampicin-susceptible isolates. Among nine patients bearing rifampicin-resistant isolates, only three (33%) had successful outcomes. CONCLUSION: Rifamycins other than rifampicin show promising antistaphylococcal activity, including antibiofilm activity. Rifamycin-resistant staphylococci exhibit rpoB gene mutations.

Prosthetic valve endocarditis by Trichosporon mucoides: A case report and review of literature.

NATIONALE: Trichosporon species are widely distributed in nature and are emerging opportunistic human pathogens. Trichosporon infections are associated with superficial cutaneous involvement in immunocompetent individuals to severe systemic disease in immunocompromised patients. Until now, there is no report in infective endocarditis by Trichosporon mucoides confirmed by molecular diagnostics PATIENT CONCERNS:: A 66-year-old man presented with a fever that had occurred for a period of 6 months. He had undergone aortic valve replacement 10 years prior. Transthoracic echocardiography showed vegetations on the prosthetic aortic valve and native mitral valve. T mucoides was detected in the cultures of blood and vegetations. DIAGNOSIS: DNA sequencing using D/D2 region of rRNA and internal transcribed spacer were performed. INTERVENTIONS: Infections were successfully controlled with valve replacement and voriconazole plus liposomal amphotericin B therapy. OUTCOMES: There has been no sign of recurrence for 18-months after treatment completion. LESSONS: This is the first reported case of infective endocarditis due to T mucoides. Clinicians should consider Trichosporon species as causative agents of endocarditis in patients who have undergone cardiac surgery.

Combined MS/MS-NMR Annotation Guided Discovery of Iris lactea var. chinensis Seed as a Source of Viral Neuraminidase Inhibitory Polyphenols.

In this study, the chemical diversity of polyphenols in Iris lactea var. chinensis seeds was identified by combined MS/MS-NMR analysis. Based on the annotated chemical profile, the isolation of stilbene oligomers was conducted, and consequently, stilbene oligomers (1-10) were characterized. Of these, compounds 1 and 2 are previously undescribed stilbene dimer glycoside (1) and tetramer glycoside (2), respectively. Besides, to evaluate this plant seed as a rich source of stilbene oligomers, we quantified three stilbene oligomers of I. lactea var. chinensis seeds. The contents of three major stilbene oligomers-trans-ε-viniferin (3), vitisin A (6), and vitisin B (9)-in I. lactea var. chinensis seeds were quantified as 2.32 (3), 4.95 (6), and 1.64 (9) mg/g dry weight (DW). All the isolated compounds were tested for their inhibitory activities against influenza neuraminidase. Compound 10 was found to be active with the half maximal inhibitory concentration (IC50) values at 4.76 µM. Taken together, it is concluded that I. lactea var. chinensis seed is a valuable source of stilbene oligomers with a human health benefit.

Clinical characteristics and risk factors for complications of candidaemia in adults: Focus on endophthalmitis, endocarditis, and osteoarticular infections.

OBJECTIVES: This study evaluated the incidence, risk factors, and clinical characteristics of complications of candidaemia in adults, with a focus on endophthalmitis, endocarditis, and osteoarticular infections. METHODS: All patients ≥18 years old with candidaemia in two Korean tertiary hospitals from 2007 to 2016 were investigated. Complications of candidaemia were defined as the presence of endophthalmitis, endocarditis, or osteoarticular infections documented in patients with candidaemia. The clinical characteristics and risk factors for candidaemia with complications were analysed in the patients who underwent ophthalmological examinations. RESULTS: Of 765 adult patients with candidaemia, 34 (4.4%) met the definition of complications, including endophthalmitis in 29 (3.8%), endocarditis in 4 (0.5%), and osteoarticular infections in 3 (0.4%). Of the 225 patients who underwent ophthalmological examinations, 29 (12.9%) had endophthalmitis. Candida albicans was an independent risk factor for complicated candidaemia (OR, 5.12; 95% CI, 2.17-12.09; P < 0.001). Although the mortality rate was no higher in complicated candidaemia, the duration of antifungal therapy was longer (23.1 ± 17.6 vs. 16.4 ± 10.8 days, P = 0.042), and 13 patients (39.3%) underwent additional procedures or surgery. CONCLUSIONS: Complications of candidaemia occurred in 4.4% of adult patients. C. albicans was an independent risk factor for complicated candidaemia in adults. Complications of candidaemia might need prolonged treatment and additional procedures or surgery. Therefore, careful evaluation and active treatment of candidaemia with complications should be encouraged.

Improvement in Left Ventricular Function with Intracoronary Mesenchymal Stem Cell Therapy in a Patient with Anterior Wall ST-Segment Elevation Myocardial Infarction.

BACKGROUND/AIMS: The progression and development of congestive heart failure is still considered a large problem despite the existence of revascularization therapies and optimal, state-of-the-art medical services. An acute myocardial infarction (AMI) is a major cause of congestive heart failure, so researchers are investigating techniques to complement primary percutaneous coronary intervention (PCI) or thrombolytic therapy to prevent congestive heart failure after AMI. METHODS: Twenty-six patients with successful PCI for acute ST-segment elevation anterior wall myocardial infarction were assigned to either a control group (n = 12) or a bone marrow mesenchymal stem cells (BM-MSC) group (n = 14). The control group received optimum post-infarction treatment, and the BMSC group received intracoronary delivery of autologous BMSC at 1 month after PCI with the optimum medical treatment. The primary endpoint was a left ventricular ejection fraction (LVEF) change from baseline to 4-month follow-up, as determined via myocardial single-photon emission computed tomography (SPECT). RESULTS: The global LVEF at baseline (determined 3.5 ± 1.5 days after PCI) was 35.4 ± 3.0% in the control group and 33.6 ± 4.7% in the BM-MSC group. BMSC transfer enhanced left ventricular systolic function primarily in anterior wall myocardial segments adjacent to the LAD infarcted area. Four months later, via SPECT, global LVEF had increased by 4.8 ± 1.9% in the control group and 8.8 ± 2.9% in the BM-MSC group (p = 0.031). The cell transfer did not increase the risk of adverse clinical events, in-stent restenosis, or proarrhythmic effects. The echocardiographic evaluation also revealed a significant increase in the LVEF value from baseline to the 4-month (9.0 ± 4.7 and 5.3 ± 2.6%, p = 0.023) and 12-month (9.9 ± 5.2% and 6.5 ± 2.7%, p = 0.048) follow-up in the BM-MSC group but not in the control group. CONCLUSIONS: Intracoronary administration of autologous BM-MSC was tolerable and safe with significant improvement in LVEF at 4-month (SPECT and echocardiography result) and 12-month (echocardiography result only) follow-up in patients with anterior AMI.

Effects on lipid peroxidation and antioxidative enzymes of Euonymus alatus in cultured rat hepatocytes.

The Euonymus alatus (Thunb.) Sieb. has long been used as a crude drug. In this paper, we investigate the effects of E. alatus on cultured hepatocyte cell system and lipid peroxidation in hydrogen peroxide (H(2)O(2)) treatment conditions. The study covers the physiological activity (the antioxidative activity and the nitrite-scavenging effect) of E. alatus. H(2)O(2) that can produce intracellular free radical was used for inducer of the peroxidation of cellular lipids. Treatment of E. alatus attenuated in cell killing enhanced by increasing concentrations of H(2)O(2). The increased malondialdehyde level induced by H(2)O(2) treatment was reduced by pre-treatment of E. alatus. Furthermore, addition of E. alatus in cell culture medium significantly reduced cell killing and content of intracellular antioxidants. Changes in nitrite-scavenging effect of E. alatus at various concentrations (5-25 mg/ml) and various pH levels (pH 1.2, 4.2 and 6.0) were also observed. The present study was also done to investigate the effects of E. alatus on cultured hepatocyte cell system, H(2)O(2)-induced cytotoxicity and antioxidative enzyme activities, including catalase, superoxide dismutase, glutathione peroxidase and glutathione S-transferase in H(2)O(2 )treatment conditions. E. alatus treatment had significant protective or elevating activities on these antioxidative enzyme activities compared to a normal group. The results indicate that E. alatus provides a strong antioxidant protection of cells against H(2)O(2)-induced oxidative stress.