Global guideline for the diagnosis and management of mucormycosis: an initiative of the European Confederation of Medical Mycology in cooperation with the Mycoses Study Group Education and Research Consortium

Mucormycosis is a difficult to diagnose rare disease with high morbidity and mortality. Diagnosis is often delayed, and disease tends to progress rapidly. Urgent surgical and medical intervention is lifesaving. Guidance on the complex multidisciplinary management has potential to improve prognosis, but approaches differ between health-care settings. From January, 2018, authors from 33 countries in all United Nations regions analysed the published evidence on mucormycosis management and provided consensus recommendations addressing differences between the regions of the world as part of the "One World One Guideline" initiative of the European Confederation of Medical Mycology (ECMM). Diagnostic management does not differ greatly between world regions. Upon suspicion of mucormycosis appropriate imaging is strongly recommended to document extent of disease and is followed by strongly recommended surgical intervention. First-line treatment with high-dose liposomal amphotericin B is strongly recommended, while intravenous isavuconazole and intravenous or delayed release tablet posaconazole are recommended with moderate strength. Both triazoles are strongly recommended salvage treatments. Amphotericin B deoxycholate is recommended against, because of substantial toxicity, but may be the only option in resource limited settings. Management of mucormycosis depends on recognising disease patterns and on early diagnosis. Limited availability of contemporary treatments burdens patients in low and middle income settings. Areas of uncertainty were identified and future research directions specified.

Isavuconazole versus voriconazole for primary treatment of invasive mould disease caused by Aspergillus and other filamentous fungi (SECURE): a phase 3, randomised-controlled, non-inferiority trial

BACKGROUND

Isavuconazole is a novel triazole with broad-spectrum antifungal activity. The SECURE trial assessed efficacy and safety of isavuconazole versus voriconazole in patients with invasive mould disease.

METHODS

This was a phase 3, double-blind, global multicentre, comparative-group study. Patients with suspected invasive mould disease were randomised in a 1:1 ratio using an interactive voice-web response system, stratified by geographical region, allogeneic haemopoietic stem cell transplantation, and active malignant disease at baseline, to receive isavuconazonium sulfate 372 mg (prodrug; equivalent to 200 mg isavuconazole; intravenously three times a day on days 1 and 2, then either intravenously or orally once daily) or voriconazole (6 mg/kg intravenously twice daily on day 1, 4 mg/kg intravenously twice daily on day 2, then intravenously 4 mg/kg twice daily or orally 200 mg twice daily from day 3 onwards). We tested non-inferiority of the primary efficacy endpoint of all-cause mortality from first dose of study drug to day 42 in patients who received at least one dose of the study drug (intention-to-treat [ITT] population) using a 10% non-inferiority margin. Safety was assessed in patients who received the first dose of study drug. This study is registered with ClinicalTrials.gov, number NCT00412893.

FINDINGS

527 adult patients were randomly assigned (258 received study medication per group) between March 7, 2007, and March 28, 2013. All-cause mortality from first dose of study drug to day 42 for the ITT population was 19% with isavuconazole (48 patients) and 20% with voriconazole (52 patients), with an adjusted treatment difference of -1·0% (95% CI -7·8 to 5·7). Because the upper bound of the 95% CI (5·7%) did not exceed 10%, non-inferiority was shown. Most patients (247 [96%] receiving isavuconazole and 255 [98%] receiving voriconazole) had treatment-emergent adverse events (p=0·122); the most common were gastrointestinal disorders (174 [68%] vs 180 [69%]) and infections and infestations (152 [59%] vs 158 [61%]). Proportions of patients with treatment-emergent adverse events by system organ class were similar overall. However, isavuconazole-treated patients had a lower frequency of hepatobiliary disorders (23 [9%] vs 42 [16%]; p=0·016), eye disorders (39 [15%] vs 69 [27%]; p=0·002), and skin or subcutaneous tissue disorders (86 [33%] vs 110 [42%]; p=0·037). Drug-related adverse events were reported in 109 (42%) patients receiving isavuconazole and 155 (60%) receiving voriconazole (p<0·001).

INTERPRETATION

Isavuconazole was non-inferior to voriconazole for the primary treatment of suspected invasive mould disease. Isavuconazole was well tolerated compared with voriconazole, with fewer study-drug-related adverse events. Our results support the use of isavuconazole for the primary treatment of patients with invasive mould disease.

FUNDING

Astellas Pharma Global Development, Basilea Pharmaceutica International.

Respiratory Syncytial Virus Prefusion F Protein Vaccine in Older Adults

BACKGROUND

Respiratory syncytial virus (RSV) is an important cause of acute respiratory infection, lower respiratory tract disease, clinical complications, and death in older adults. There is currently no licensed vaccine against RSV infection.

METHODS

In an ongoing, international, placebo-controlled, phase 3 trial, we randomly assigned, in a 1:1 ratio, adults 60 years of age or older to receive a single dose of an AS01_E-adjuvanted RSV prefusion F protein-based candidate vaccine (RSVPreF3 OA) or placebo before the RSV season. The primary objective was to show vaccine efficacy of one dose of the RSVPreF3 OA vaccine against RSV-related lower respiratory tract disease, confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR), during one RSV season. The criterion for meeting the primary objective was a lower limit of the confidence interval around the efficacy estimate of more than 20%. Efficacy against severe RSV-related lower respiratory tract disease and RSV-related acute respiratory infection was assessed, and analyses according to RSV subtype (A and B) were performed. Safety was evaluated.

RESULTS

A total of 24,966 participants received one dose of the RSVPreF3 OA vaccine (12,467 participants) or placebo (12,499). Over a median follow-up of 6.7 months, vaccine efficacy against RT-PCR-confirmed RSV-related lower respiratory tract disease was 82.6% (96.95% confidence interval [CI], 57.9 to 94.1), with 7 cases (1.0 per 1000 participant-years) in the vaccine group and 40 cases (5.8 per 1000 participant-years) in the placebo group. Vaccine efficacy was 94.1% (95% CI, 62.4 to 99.9) against severe RSV-related lower respiratory tract disease (assessed on the basis of clinical signs or by the investigator) and 71.7% (95% CI, 56.2 to 82.3) against RSV-related acute respiratory infection. Vaccine efficacy was similar against the RSV A and B subtypes (for RSV-related lower respiratory tract disease: 84.6% and 80.9%, respectively; for RSV-related acute respiratory infection: 71.9% and 70.6%, respectively). High vaccine efficacy was observed in various age groups and in participants with coexisting conditions. The RSVPreF3 OA vaccine was more reactogenic than placebo, but most adverse events for which reports were solicited were transient, with mild-to-moderate severity. The incidences of serious adverse events and potential immune-mediated diseases were similar in the two groups.

CONCLUSIONS

A single dose of the RSVPreF3 OA vaccine had an acceptable safety profile and prevented RSV-related acute respiratory infection and lower respiratory tract disease and severe RSV-related lower respiratory tract disease in adults 60 years of age or older, regardless of RSV subtype and the presence of underlying coexisting conditions. (Funded by GlaxoSmithKline Biologicals; AReSVi-006 ClinicalTrials.gov number, NCT04886596.).

Combination antifungal therapy for invasive aspergillosis: a randomized trial

BACKGROUND

Invasive aspergillosis (IA) is associated with poor outcomes in patients with hematologic malignancies (HMs) and hematopoietic cell transplantation (HCT). Small studies suggest a role for combination antifungal therapy.

OBJECTIVE

To assess the safety and efficacy of voriconazole and anidulafungin compared with voriconazole monotherapy for treatment of IA.

DESIGN

Randomized, double-blind, placebo-controlled multicenter trial. (ClinicalTrials.gov: NCT00531479).

SETTING

93 international sites.

PATIENTS

454 patients with HM or HCT and suspected or documented IA were randomly assigned to treatment with voriconazole and anidulafungin or placebo. Primary analysis was done in the modified intention-to-treat population of 277 patients in whom IA was confirmed.

MEASUREMENTS

The primary outcome was 6-week mortality; secondary outcomes included 12-week mortality, mortality in major subgroups, and safety measures.

RESULTS

Mortality rates at 6 weeks were 19.3% (26 of 135) for combination therapy and 27.5% (39 of 142) for monotherapy (difference, -8.2 percentage points [95% CI, -19.0 to 1.5]; P  = 0.087). Secondary mortality outcomes favored combination therapy. Multivariable regression analysis suggested that maximum galactomannan value, Karnofsky score, and baseline platelet count had prognostic significance. Most patients (218 of 277 [78.7%]) had IA diagnosis established by radiographic findings and maximum galactomannan positivity. In a post hoc analysis of this dominant subgroup, 6-week mortality was lower in combination therapy than monotherapy (15.7% [17 of 108] vs. 27.3% [30 of 110]; difference, -11.5 percentage points [CI, -22.7 to -0.4]; P = 0.037). Safety measures, including hepatotoxicity, were not different.

LIMITATIONS

Mortality at 6 weeks was higher than expected, and the difference in mortality was lower than expected, which reduced power to detect a treatment effect. Enrollment was restricted to patients with HM or HCT, which limited generalizability.

CONCLUSION

Compared with voriconazole monotherapy, combination therapy with anidulafungin led to higher survival in subgroups of patients with IA. Limitations in power preclude definitive conclusions about superiority.

PRIMARY FUNDING SOURCE

Pfizer.

Architecture of the yeast origin recognition complex bound to origins of DNA replication

In many organisms, the replication of DNA requires the binding of a protein called the initiator to DNA sites referred to as origins of replication. Analyses of multiple initiator proteins bound to their cognate origins have provided important insights into the mechanism by which DNA replication is initiated. To extend this level of analysis to the study of eukaryotic chromosomal replication, we have investigated the architecture of the Saccharomyces cerevisiae origin recognition complex (ORC) bound to yeast origins of replication. Determination of DNA residues important for ORC-origin association indicated that ORC interacts preferentially with one strand of the ARS1 origin of replication. DNA binding assays using ORC complexes lacking one of the six subunits demonstrated that the DNA binding domain of ORC requires the coordinate action of five of the six ORC subunits. Protein-DNA cross-linking studies suggested that recognition of origin sequences is mediated primarily by two different groups of ORC subunits that make sequence-specific contacts with two distinct regions of the DNA. Implications of these findings for ORC function and the mechanism of initiation of eukaryotic DNA replication are discussed.

Effect of Recombinant Zoster Vaccine on Incidence of Herpes Zoster After Autologous Stem Cell Transplantation: A Randomized Clinical Trial

IMPORTANCE

Herpes zoster, a frequent complication following autologous hematopoietic stem cell transplantation (HSCT), is associated with significant morbidity. A nonlive adjuvanted recombinant zoster vaccine has been developed to prevent posttransplantation zoster.

OBJECTIVE

To assess the efficacy and adverse event profile of the recombinant zoster vaccine in immunocompromised autologous HSCT recipients.

DESIGN, SETTING, AND PARTICIPANTS

Phase 3, randomized, observer-blinded study conducted in 167 centers in 28 countries between July 13, 2012, and February 1, 2017, among 1846 patients aged 18 years or older who had undergone recent autologous HSCT.

INTERVENTIONS

Participants were randomized to receive 2 doses of either recombinant zoster vaccine (n = 922) or placebo (n = 924) administered into the deltoid muscle; the first dose was given 50 to 70 days after transplantation and the second dose 1 to 2 months thereafter.

MAIN OUTCOMES AND MEASURES

The primary end point was occurrence of confirmed herpes zoster cases.

RESULTS

Among 1846 autologous HSCT recipients (mean age, 55 years; 688 [37%] women) who received 1 vaccine or placebo dose, 1735 (94%) received a second dose and 1366 (74%) completed the study. During the 21-month median follow-up, at least 1 herpes zoster episode was confirmed in 49 vaccine and 135 placebo recipients (incidence, 30 and 94 per 1000 person-years, respectively), an incidence rate ratio (IRR) of 0.32 (95% CI, 0.22-0.44; P < .001), equivalent to 68.2% vaccine efficacy. Of 8 secondary end points, 3 showed significant reductions in incidence of postherpetic neuralgia (vaccine, n=1; placebo, n=9; IRR, 0.1; 95% CI, 0.00-0.78; P = .02) and of other prespecified herpes zoster-related complications (vaccine, n=3; placebo, n=13; IRR, 0.22; 95% CI, 0.04-0.81; P = .02) and in duration of severe worst herpes zoster-associated pain (vaccine, 892.0 days; placebo, 6275.0 days; hazard ratio, 0.62; 95% CI, 0.42-0.89; P = .01). Five secondary objectives were descriptive. Injection site reactions were recorded in 86% of vaccine and 10% of placebo recipients, of which pain was the most common, occurring in 84% of vaccine recipients (grade 3: 11%). Unsolicited and serious adverse events, potentially immune-mediated diseases, and underlying disease relapses were similar between groups at all time points.

CONCLUSIONS AND RELEVANCE

Among adults who had undergone autologous HSCT, a 2-dose course of recombinant zoster vaccine compared with placebo significantly reduced the incidence of herpes zoster over a median follow-up of 21 months.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01610414.

Factors associated with the success rate of orthodontic miniscrews placed in the upper and lower posterior buccal region

OBJECTIVE

To determine the success rate and the factors related to the success rate of orthodontic miniscrew implants (OMI) placed at the attached gingiva of the posterior buccal region.

MATERIALS AND METHODS

Four hundred eighty OMI placed in 209 orthodontic patients were examined retroactively. The sample was divided into young patients (range 10-18 years, N = 108) and adult patients (range 19-64 years, N = 109). The placement site was divided into three interdental areas from the first premolar to the second molar in the maxilla and mandible. According to soft tissue management, the samples were divided into incision and nonincision groups. Chi-square tests and multiple logistic regression analyses were used.

RESULTS

The overall success rate was 83.8%. Dislodgement of the OMI occurred most frequently in the first 1-2 months, and more than 90% of the failures occurred within the first 4 months. Sex, age, jaw, soft tissue management, and placement side did not show any difference in the success rate. Placement site, however, showed a significant difference in the mandible of adult patients. There was no difference in the success rate in the maxilla.

CONCLUSIONS

Placement site is one of the important factors for success rate of OMI.

Posaconazole versus voriconazole for primary treatment of invasive aspergillosis: a phase 3, randomised, controlled, non-inferiority trial

BACKGROUND

Voriconazole has been recommended as primary treatment for patients with invasive aspergillosis. Intravenous and tablet formulations of posaconazole that have improved systemic absorption could be an effective alternative to voriconazole. We aimed to assess non-inferiority of posaconazole to voriconazole for the primary treatment of invasive aspergillosis.

METHODS

We did a randomised, prospective, double-blind, double-dummy, controlled trial comparing posaconazole (intravenous or oral posaconazole 300 mg twice on day 1, followed by 300 mg once a day for days 2-84) with voriconazole (6 mg/kg intravenous or 300 mg oral twice on day 1 followed by 4 mg/kg intravenously or 200 mg orally twice a day for days 2-84) for 12 weeks or less in the primary treatment of invasive aspergillosis. Participants were from 91 study sites in 26 countries, were aged 13 years or older, weighed at least 40 kg, and met criteria for proven, probable, or possible fungal disease. Participants were randomly assigned (1:1) via a computer-generated randomisation schedule with stratification by risk status. The primary endpoint was cumulative all-cause mortality up until day 42 in the intention-to-treat (ITT) population (defined as randomly assigned participants who received ≥1 dose of study drug), with a 10% non-inferiority margin. The ITT population was also evaluated for safety. This study is registered with ClinicalTrials.gov, NCT01782131, and EudraCT, 2011-003938-14.

FINDINGS

Between Oct 25, 2013, and Sept 10, 2019, of 653 individuals assessed for eligibility, 575 ITT participants were randomly assigned and received one or more doses of study drug (n=288 [50%] posaconazole, n=287 [50%] voriconazole). Mortality up until day 42 was 15% (44 of 288) in the posaconazole group and 21% (59 of 287) in the voriconazole group (treatment difference -5·3% [95% CI -11·6 to 1·0]; p<0·0001). Mortality up until day 42 in the full-analysis-set subpopulation (ITT participants with proven or probable invasive aspergillosis) supported this conclusion: 31 (19%) of 163 participants in the posaconazole group and 32 (19%) of 171 participants in the voriconazole group (treatment difference 0·3% [95% CI -8·2 to 8·8]). The most frequently reported treatment-related adverse events (incidence >3%) were increased aspartate aminotransferase (AST) or alanine aminotransferase (ALT), nausea, hypokalaemia, and vomiting in the posaconazole group and increased ALT, AST, or alkaline phosphatase, hallucination, increased γ-glutamyltransferase peptidase, nausea, and blurred vision in the voriconazole group. The overall incidence of treatment-related adverse event rates in the ITT population was 30% for posaconazole and 40% for voriconazole (treatment difference -10·2% [95% CI -17·9 to -2·4]).

INTERPRETATION

Posaconazole was non-inferior to voriconazole for all-cause mortality up until day 42 in participants with invasive aspergillosis. Posaconazole was well tolerated, and participants had fewer treatment-related adverse events than in the voriconazole group. This study supports the use of posaconazole as a first-line treatment for the condition.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Inc.

Calreticulin, a calcium-binding molecular chaperone, is required for stress response and fertility in Caenorhabditis elegans

Calreticulin (CRT), a Ca(2+)-binding protein known to have many cellular functions, including regulation of Ca(2+) homoeostasis and chaperone activity, is essential for heart and brain development during embryogenesis in mice. Here, we report the functional characterization of Caenorhabditis elegans calreticulin (crt-1). A crt-1 null mutant does not result in embryonic lethality but shows temperature-dependent reproduction defects. In C. elegans CRT-1 is expressed in the intestine, pharynx, body-wall muscles, head neurons, coelomocytes, and in sperm. crt-1 males exhibit reduced mating efficiency and defects late in sperm development in addition to defects in oocyte development and/or somatic gonad function in hermaphrodites. Furthermore, crt-1 and itr-1 (inositol triphosphate receptor) together are required for normal behavioral rhythms. crt-1 transcript level is elevated under stress conditions, suggesting that CRT-1 may be important for stress-induced chaperoning function in C. elegans.

ATPase switches controlling DNA replication initiation

Proteins that bind and hydrolyze ATP are frequently involved in the early steps of DNA replication. Recent studies of Saccharomyces cerevisiae suggest that two members of the AAA+ ATPase family--the origin recognition complex and Cdc6p--have separable roles for ATP binding and ATP hydrolysis during eukaryotic DNA replication. Intriguingly, the proposed regulation of these eukaryotic replication proteins by ATP has functional similarities to the ATP-dependent control of the DnaA and DnaC initiation factors from Escherichia coli. Comparison of the ATP regulation of these factors suggests that ATP binding and hydrolysis acts as a molecular switch that couples key events during initiation of replication. This switch results in a significant change in protein function.

Cytomegalovirus Infections after Hematopoietic Stem Cell Transplantation: Current Status and Future Immunotherapy

Cytomegalovirus (CMV) infection after hematopoietic stem cell transplantation (HSCT) is one of the critical infectious complications related to host immune recovery. The spectrum of CMV infection is quite extensive, from asymptomatic CMV reactivation presenting mainly as CMV DNAemia to fatal CMV diseases involving gut, liver, lungs, or brain. In addition to organ involvement, CMV reactivation can exert indirect effects such as immunosuppression or graft failure that may result in the development of concurrent infectious complications. Currently, preemptive therapy, which is based on PCR-based monitoring of CMV from blood, is a mainstay enabling improvement in CMV-related outcomes. During the past decades, new antiviral drugs, clinical trials for prophylaxis in high-risk groups, and vaccines for preventing CMV infection have been introduced. In addition, data for immunologic monitoring and adoptive immunotherapy have also been accumulated. Here, we review the current status and recent updates in this field, with future perspectives including immunotherapy in HSCT recipients.

Multiplex PCR for the detection of genes encoding aminoglycoside modifying enzymes and methicillin resistance among Staphylococcus species

We developed multiplex polymerase chain reaction (PCR) to detect aac(6 ')/aph(2 "), aph(3 ')-IIIa, and ant(4 ')-Ia, the genes encoding the most clinically relevant amino-glycoside modifying enzymes (AME), and simultaneously, the methicillin resistant gene, mecA, in Staphylococcus species. Clinical isolates of 45 S. aureus and 47 coagulase negative staphylococci (CNS) from tertiary university hospitals were tested by conventional susceptibility testing, using the agar dilution method and by multiplex PCR. Of a total of 92 isolates, 61 isolates were found to be methicillin-resistant. Of these, 54 isolates (89%) were found to be harboring mecA. Seventy-five percent of the 92 isolates demonstrated resistance to at least one of the aminoglycosides tested. Moreover, resistance to aminoglycosides was closely associated with methicillin-resistance (p<0.05). The most prevalent AME gene was aac(6 ')/aph(2 ") which was found in 65% of the isolates, and ant(4 ')-Ia and aph(3 ')-IIIa were present in 41% and 9% of the isolates, respectively. The concordance between methicillin-resistance and the presence of mecA gene was 98% in S. aureus and 81% in CNS. The concordance between gentamicin resistance and the presence of aac(6 ')/aph(2 ") gene was 100% in S. aureus and 85% in CNS. The multiplex PCR method that we developed appears to be both a more rapid and reliable than conventional method.

Antibacterial, antitumor and hemolytic activities of alpha-helical antibiotic peptide, P18 and its analogs

The alpha-helical antibiotic peptide (P18: KWKLFKKIPKFLHLAKKF-NH2) designed from the cecropin A(1-8)-magainin 2 (1-12) hybrid displayed strong bactericidal and tumoricidal activity without inducing hemolysis. The effect of the Pro9 residue at central position of P18 on cell selectivity was investigated by Pro9 --> Leu or Pro9 --> Ser substitution. Either substitution markedly reduced the antibacterial activity of P18 and increased hemolysis, although it did not significantly affect cytotoxicity against human transformed tumor and normal fibroblast cells. These results suggest that a proline kink in alpha-helical antibiotic peptide P18 serves as a hinge region to facilitate ion channel formation on bacterial cell membranes and thus plays an important role in providing high selectivity against bacterial cells. Furthermore, to investigate the structure-antibiotic activity relationships of P18, a series of N- or C-terminal deletion and substitution analogs of P18 were synthesized. The C-terminal region of P18 was related to its antibiotic activity and alpha-helical conformation on lipid membranes rather than N-terminal one. Higher alpha-helicity of the peptides was involved in the hemolytic and antitumor activity rather than antibacterial activity. Except for [L9]-P18 and [S9]-P18, all the designed peptides containing a Pro residue showed potent antibacterial activity, although they did not induce a cytolytic effect against human erythrocyte and normal fibroblast cells at the concentration required to kill bacteria. In particular, P18 and some analogs (N-1, N-2, N-3, N-3L and N-4L) with potent bactericidal and tumoricidal activity and little or no normal cell toxicity may serve as an attractive candidate for the development of novel anti-infective or antitumor agents.

Evidence-based guidelines for empirical therapy of neutropenic fever in Korea

Neutrophils play an important role in immunological function. Neutropenic patients are vulnerable to infection, and except fever is present, inflammatory reactions are scarce in many cases. Additionally, because infections can worsen rapidly, early evaluation and treatments are especially important in febrile neutropenic patients. In cases in which febrile neutropenia is anticipated due to anticancer chemotherapy, antibiotic prophylaxis can be used, based on the risk of infection. Antifungal prophylaxis may also be considered if long-term neutropenia or mucosal damage is expected. When fever is observed in patients suspected to have neutropenia, an adequate physical examination and blood and sputum cultures should be performed. Initial antibiotics should be chosen by considering the risk of complications following the infection; if the risk is low, oral antibiotics can be used. For initial intravenous antibiotics, monotherapy with a broad-spectrum antibiotic or combination therapy with two antibiotics is recommended. At 3-5 days after beginning the initial antibiotic therapy, the condition of the patient is assessed again to determine whether the fever has subsided or symptoms have worsened. If the patient's condition has improved, intravenous antibiotics can be replaced with oral antibiotics; if the condition has deteriorated, a change of antibiotics or addition of antifungal agents should be considered. If the causative microorganism is identified, initial antimicrobial or antifungal agents should be changed accordingly. When the cause is not detected, the initial agents should continue to be used until the neutrophil count recovers.

Regulation of origin recognition complex conformation and ATPase activity: differential effects of single-stranded and double-stranded DNA binding

The Saccharomyces cerevisiae origin recognition complex (ORC) is bound to origins of DNA replication throughout the cell cycle and directs the assembly of higher-order protein-DNA complexes during G(1). To examine the fate of ORC when origin DNA is unwound during replication initiation, we determined the effect of single-stranded DNA (ssDNA) on ORC. We show that ORC can bind ssDNA and that ORC bound to ssDNA is distinct from that bound to double-stranded origin DNA. ssDNA stimulated ORC ATPase activity, whereas double-stranded origin DNA inhibited the same activity. Electron microscopy studies revealed two alternative conformations of ORC: an extended conformation stabilized by origin DNA and a bent conformation stabilized by ssDNA. Therefore, ORC appears to exist in two distinct states with respect to its conformation and ATPase activity. Interestingly, the effect of ssDNA on these properties of ORC is correlated with ssDNA length. Since double-stranded origin DNA and ssDNA differentially stabilize these two forms of ORC, we propose that origin unwinding triggers a transition between these alternative states.

The kinetics of circulating cytokines including IL-6, TNF-alpha, IL-8 and IL-10 following allogeneic hematopoietic stem cell transplantation

Pro-inflammatory (IL-6, TNFalpha and IL-8) and anti-inflammatory (IL-10) cytokines were determined in weekly samples from 52 patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). IL-6 increased immediately after transplant peaking at week +3, but IL-8 concentrations were elevated only during week +1. After a slight decrease in week +1, TNF-alpha significantly increased from week +2 and peaked at week +3, whereas, IL-10 values started to rise in week +2 and peaked during week +4. IL-6 and TNF-alpha were positively correlated from week +2 to week +4, and IL-6 levels at week +1 were related with fever and severe stomatitis. Serum levels of IL-6 at week +1 and IL-10 at week +4 were significantly higher in patients with early transplant-related complications, such as fever, severe stomatitis or acute GVHD > or = overall grade II than in those without the complications. We conclude that a high serum IL-6 level at week +1 may be an early predictor of transplant-related complications and that it seems to trigger pro- and anti-inflammatory cytokine release. Kinetic patterns of IL-6 and IL-10 were more exaggerated in those with complications after HSCT.

Purification and characterization of a novel chitinase from the entomopathogenic fungus, Metarhizium anisopliae

A novel chitinase was detected in extracellular culture fluids of the entomopathogenic fungus Metarhizium anisopliae (ATCC 20500) grown in liquid medium containing chitin as a sole carbon source. A chitinase was purified to near homogeneity from culture broth of M. anisopliae by DEAE-Sephacel, CM-Sepharose CL-6B ion-exchange chromatography, and gel filtration with Superose 12HR. The molecular mass of the enzyme determined by SDS-polyacrylamide gel electrophoresis was approximately 60 kDa and the optimum pH of the enzyme was 5.0. This molecular mass is different from values of 33, 43.5, and 45 kDa for endochitinases and 110 kDa for an exochitinase (N-acetylglucosaminidase) from M. anisopliae ME-1 published previously. In addition, N-terminal sequences of 60-kDa chitinase are different from those of 43.4- and 45-kDa endochitinases. The purified enzyme showed high chitinolytic activity against colloidal, crystalline chitin of crab shells as well as against p-nitrophenyl-beta-d-N-acetylglucosamide, p-nitrophenyl-beta-d-N, N'-diacetylchitobiose, and p-nitrophenyl-N, N'-N"-triacetylchitotriose, indicating that this enzyme has both endo- and exochitinase activity.

Internalization of tenecin 3 by a fungal cellular process is essential for its fungicidal effect on Candida albicans

Tenecin 3 is a glycine-rich, antifungal protein of 78 residues isolated from the insect Tenebrio molitor larva. As an initial step towards understanding the antifungal mechanism of tenecin 3, we examined how this protein interacts with the pathogenic fungus Candida albicans to exert its antifungal action. Tenecin 3 did not induce the release of a fluorescent dye trapped in the artificial membrane vesicles and it did not perturb the membrane potential of C. albicans by the initial interaction. Fluorescence confocal microscopy and flow cytometric analysis revealed that tenecin 3 is rapidly internalized into the cytoplasmic space in energy-dependent and temperature-dependent manners. This internalization is also dependent on the ionic environment and cellular metabolic states. These results suggest that the internalization of tenecin 3 into the cytoplasm of C. albicans is mediated by a fungal cellular process. The internalized tenecin 3 is dispersed in the cytoplasm, and the loss of cell viability occurs after this internalization.

Clinical role of interstitial pneumonia in patients with scrub typhus: a possible marker of disease severity

Interstitial pneumonia (IP) frequently occurs in patients with scrub typhus, but its clinical significance is not well known. This study was designed to evaluate interstitial pneumonia as a marker of severity of the disease for patients with scrub typhus. We investigated clinical parameters representing the severity of the disease, and the chest radiographic findings for 101 patients with scrub typhus. We then compared these clinical factors between patients with and without IP. We also studied the relationship between IP and other chest radiographic findings. The chest radiography showed IP (51.4%), pleural effusion (42.6%), cardiomegaly (14.9%), pulmonary alveolar edema (20.8%), hilar lymphadenopathy (13.8%) and focal atelectasis (11.8%), respectively. The patients with IP (n=52) had higher incidences in episode of hypoxia (p=0.030), hypotension (p=0.024), severe thrombocytopenia (p=0.036) and hypoalbuminemia (p=0.013) than the patients without IP (n=49). The patients with IP also had higher incidences of pleural effusion (p<0.001), focal atelectasis (p=0.019), cardiomegaly (p<0.001), pulmonary alveolar edema (p=0.011) and hilar lymphadenopathy (p<0.001) than the patients without IP. Our data suggest that IP frequently occurs for patients with scrub typhus and its presence is closely associated with the disease severity of scrub typhus.

Emergence of Community-Associated Methicillin-ResistantStaphylococcus aureusStrains as a Cause of Healthcare-Associated Bloodstream Infections in Korea

Background.

The prevalence of community-associated methicillin-resistantStaphylococcus aureus(CA-MRSA) strains causing bloodstream infection (BSI) has not been studied in Korea.

Objective.

We sought to determine the prevalence of CA-MRSA strains among isolates recovered from patients with MRSA BSIs and to explore epidemiological changes in Korea. We also sought to evaluate clinical characteristics relevant to the development of healthcare-associated BSIs.

Methods.

We prospectively collected consecutive MRSA isolates from patients with BSI at 4 hospitals from July 1 through November 30, 2007, and we also included MRSA isolates recovered from culture of blood samples collected during a previous year (October 1, 2004 through September 30, 2005) at a different hospital. Molecular typing studies were performed, including pulsed-field gel electrophoresis (PFGE), multilocus sequence typing,Staphylococcusprotein A (spa) typing, and staphylococcal cassette chromosomemec(SCCmec) typing. We compared the clinical characteristics and outcomes of patients with healthcare-associated BSI due to CA-MRSA strains with those of patients with healthcare-associated BSI due to healthcare-associated MRSA (HA-MRSA) strains.

Results.

There were 76 cases of MRSA BSI, of which 4 (5.3%) were community-associated and 72 (94.7%) were healthcare-associated. Among the 72 HA-MRSA BSIs, 18 (25%) were community onset, and 54 (75%) were hospital onset. PFGE type D-ST72–spaB-SCCmectype IVA MRSA, the predominant genotype of CA-MRSA in Korea, accounted for 19 (25%) of all 76 MRSA BSIs, including 17 (23.6%) of 72 HA-MRSA BSIs and 11 (20.8%) of 53 hospital-onset HA-MRSA BSIs. Patients with healthcare-associated BSIs due to CA-MRSA strains carrying SCCmectype IVA tended to have fewer healthcare-associated risk factors, compared with patients with healthcare-associated BSIs due to HA-MRSA strains carrying other SCCmectypes. The presence of a central venous catheter or other invasive device was the only independent factor differentiating patients infected with hospital-associated genotype strains from patients infected with other strains. Clinical outcomes were similar between both groups.

Conclusions.

CA-MRSA strains are emerging as a major cause of BSI in healthcare settings in Korea. This changing epidemiology of MRSA poses a challenge to public health and infection control in hospital settings.

Voriconazole-related severe adverse events: clinical application of therapeutic drug monitoring in Korean patients

BACKGROUND

Voriconazole is a triazole agent with excellent antifungal activity against Aspergillus species. However, despite its potential advantages, the occurrence of unpredictable toxicities might be critical in immunocompromised patients. The aim of this study was to analyze risk factors for voriconazole-related severe adverse events (SAEs).

METHODS

This prospective observational study was conducted in Korean patients with hematological malignancies and invasive aspergillosis on intravenous voriconazole therapy between June 2008 and April 2009.

RESULTS

Of the 25 patients enrolled, eight (32%) showed voriconazole-related SAEs, which included hepatotoxicities (n=5), cardiac tachyarrhythmias (n=2), and neurotoxicity (n=1). Sex, age, underlying hematological malignancies, voriconazole dose, the co-administration of a proton pump inhibitor, and CYP2C19 genotype were not found to be related to the occurrence of SAEs. However, trough plasma concentrations of voriconazole were found to be significantly higher in the patients with an SAE: median 6.32 mg/l (interquartile range (IQR) 2.86-9.71 mg/l) vs. median 2.15 mg/l (IQR 0.92-4.00 mg/l); p=0.011. Receiver operating characteristic curve analysis identified a cut-off trough concentration for SAEs of 5.83 mg/l (sensitivity 62.5% and specificity 94.1%). Furthermore, multivariate analysis showed that a trough concentration of ≥ 5.83mg/l was the only significant independent risk factor of an SAE.

CONCLUSIONS

This study shows that therapeutic drug monitoring is indicated in patients with a voriconazole-related SAE and that dose adjustment is required if the trough concentration of voriconazole exceeds 5.83 mg/l.

Involvement of nuclear factor-kappa B in platelet-activating factor-mediated tumor necrosis factor-alpha expression

Tumor necrosis factor (TNF)-alpha and platelet-activating factor (PAF) are important mediators of inflammatory reactions, and their release is controlled by a positive feedback network. However, the regulatory mechanisms underlying the interaction of these two molecules are unknown. Within 10 min of the injection of lipopolysaccharide (LPS) into C57BL/6 mice, effects inducible by PAF such as anaphylactic shock-like symptoms, disseminated intravascular coagulation, and hemorrhage in renal medullae were observed, and all these pathological changes were prevented by the PAF antagonist, BN 50739. The plasma level of PAF after LPS injection reached a peak at 5 min. TNF-alpha gene expression was evident 20 min after LPS injection and was maximal at 40 min, and the level of serum TNF-alpha reached a peak at 1 h. Pretreatment with BN 50739 inhibited LPS-induced TNF-alpha gene expression and protein synthesis in a dose-dependent manner. Injection of PAF or treatment of the macrophage cell line, J774A.1, with PAF activated the transcription factor, nuclear factor (NF)-kappa B, which is essential for inducible TNF-alpha transcription. The activation of NF-kappa B by PAF preceded the LPS-mediated TNF-alpha gene expression. Pretreatment with BN 50739 inhibited LPS-induced mobilization of NF-kappa B in a dose-dependent manner in vivo as well as in vitro. These data suggest that PAF, which is released immediately or shortly after LPS injection, induces the expression of TNF-alpha through the activation of NF-kappa B.

Allogeneic Stem Cell Transplantation in First Complete Remission Enhances Graft-versus-Leukemia Effect in Adults with Acute Lymphoblastic Leukemia: Antileukemic Activity of Chronic Graft-versus-Host Disease

The aim of the present study was to identify graft-versus-leukemia effects and the factors that affect outcome in 201 adults with acute lymphobalstic leukemia who received myeloablative allogeneic stem cell transplantation from matched sibling or unrelated donors (1995-2004). One hundred seventy-eight (88.6%) of these patients had high-risk criteria, and 151 (75.1%) patients were transplanted in first complete remission (CR). All patients received unmodified stem cell grafts (185 bone marrow and 16 peripheral blood) following total- body irradiation-containing myeloablative preparations. Graft-versus-host disease (GVHD) prophylaxis was uniformly attempted by administering calcineurin inhibitor plus methotrexate. After a median follow-up of 63 months (range: 25+ to 139+ months) for surviving transplants, disease-free survival at 5 years was 47.8% for all patients and 60.3% for patients in the first CR. No difference in transplantation outcome was observed between sibling and unrelated transplants in the first CR. The most powerful predictive factor affecting transplantation outcome was disease status at transplantation (the first CR versus beyond the first CR, P<.001). Chronic GVHD (cGVHD), especially limited type, was also found to have a significant antileukemic effect. Interestingly, the influence of cGVHD on relapse risk was prominent in patients with chromosomal translocations or normal cytogenetics.

Molecular epidemiology of extended-spectrum β-lactamase-producing Escherichia coli in the community and hospital in Korea: emergence of ST131 producing CTX-M-15

BACKGROUND

The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has been increased not only in the hospital but also in the community worldwide. This study was aimed to characterize ESBL- producing E. coli isolates and to investigate the molecular epidemiology of community isolates in comparison with hospital isolates at a single center in Korea.

METHODS

A total of 142 ESBL-producing E. coli isolates were collected at Daejeon St Mary's Hospital in Korea from January 2008 to September 2009. The ESBLs were characterized by PCR sequencing using specific primers. The genetic relatedness was determined by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).

RESULTS

Of 142 isolates, 139 were positive for CTX-M type ESBLs; CTX-M-14 (n = 69, 49.6 %), CTX-M-15 (n = 53, 38.1 %) and both CTX-M-14 and -15 (n = 17, 12.2 %). CTX-M-14 and CTX-M-15 were detected in both community and hospital isolates whereas isolates producing both CTX-M14 and-15 were mainly identified in the hospital. CTX-M producing E. coli isolates were genetically heterogeneous, revealing 75 distinct PFGE types. By MLST, 21 distinctive STs including 5 major STs (ST131, ST405, ST38, ST10, and ST648) were identified. Major STs were distributed in both community and hospital isolates, and ST131 was the predominant clone regardless of the locations of acquisition. No specific major STs were confined to a single type of ESBLs. However, ST131 clones were significantly associated with CTX-M-15 and the majority of them were multidrug-resistant. Distinctively, we identified a hospital epidemic caused by the dissemination of an epidemic strain, ST131-PFGE type 10, characterized by multidrug resistance and co-producing both CTX-Ms with OXA-1 or TEM-1b.

CONCLUSIONS

The epidemiology of ESBL-producing E. coli is a complex and evolving phenomenon attributed to the horizontal transfer of genetic elements and clonal spread of major clones, predominantly ST131. The multidrug resistant ST131 clone producing CTX-M-15 has emerged as a major clone in both the community and hospital, suggesting the widespread of this epidemic clone in Korea.