Impact of an antimicrobial stewardship programme on antibiotic utilization and resistance burden in patients with acute leukaemia: an 11-year longitudinal cohort study using interrupted time-series analysis.

BACKGROUND: Antimicrobial resistance (AMR), driven by inappropriate and overuse of antibiotics, poses a significant threat, especially to patients with acute leukaemia. OBJECTIVES: To evaluate the impact of antimicrobial stewardship programmes (ASPs) on antibiotic use and analyse temporal changes in bloodstream infections (BSI) caused by AMR organisms. METHODS: We performed a retrospective, interventional, longitudinal cohort study spanning an 11-year period. ASPs included optimizing antibiotic use, enhancing tracking and reporting systems and delineating leadership and accountability. A segmented regression model of interrupted time series was used to evaluate the trend of antibiotic consumption and BSI with AMR organisms after the interventions. RESULTS: A total of 3296 BSI episodes with 454 419 days of therapy (DOT) from 7754 patients were obtained. ASPs were significantly associated with an immediate reduction [-70.03 DOT/1000 patient-days (PD), P = 0.036] and a decreasing trend (-11.65 DOT/1000 PD per quarter, P < 0.001) in overall antibiotic use. The increasing incidence of BSI with AMR before ASP intervention was notably curbed and revealed a decreasing trend (slope change: -0.06 BSI/1000 PD per quarter, P = 0.002). The decreasing trend was more significant for Enterobacterales: ciprofloxacin-resistant and ESBL-producing isolates showed a slope change of -0.06 BSI/1000 PD and -0.08 BSI/1000 PD per quarter, respectively (all P < 0.05). However, Pseudomonas aeruginosa BSI increased. CONCLUSIONS: Multidimensional ASPs effectively reduced both the immediate and trends in overall antibiotic usage even in patients with acute leukaemia. Additionally, there was a notable decrease in the incidence of BSI caused by AMR organisms, particularly among Enterobacterales.

2,4,6-Triphenyl-1-hexene, an Anti-Melanogenic Compound from Marine-Derived Bacillus sp. APmarine135.

Although melanin protects against ultraviolet radiation, its overproduction causes freckles and senile lentigines. Recently, various biological effects of metabolites derived from marine microorganisms have been highlighted due to their potential for biological and pharmacological applications. In this study, we discovered the anti-melanogenic effect of Bacillus sp. APmarine135 and verified the skin-whitening effect. Fractions of APmarine135 showed the melanin synthesis inhibition effect in B16 melanoma cells, and 2,4,6-triphenyl-1-hexene was identified as an active compound. The melanogenic capacity of 2,4,6-triphenyl-1-hexene (1) was investigated by assessing the intracellular melanin content in B16 cells. Treatment with 5 ppm of 2,4,6-triphenyl-1-hexene (1) for 72 h suppressed the α-melanocyte-stimulating hormone (α-MSH)-induced intracellular melanin increase to the same level as in the untreated control group. Additionally, 2,4,6-triphenyl-1-hexene (1) treatment suppressed the activity of tyrosinase, the rate-limiting enzyme for melanogenesis. Moreover, 2,4,6-triphenyl-1-hexene (1) treatment downregulated tyrosinase, Tyrp-1, and Tyrp-2 expression by inhibiting the microphthalmia-associated transcription factor (MITF). Furthermore, 2,4,6-triphenyl-1-hexene (1) treatment decreased the melanin content in the three-dimensional (3D) human-pigmented epidermis model MelanoDerm and exerted skin-whitening effects. Mechanistically, 2,4,6-triphenyl-1-hexene (1) exerted anti-melanogenic effects by suppressing tyrosinase, Tyrp-1, and Tyrp-2 expression and activities via inhibition of the MITF. Collectively, these findings suggest that 2,4,6-triphenyl-1-hexene (1) is a promising anti-melanogenic agent in the cosmetic industry.

Advancing diagnostic efficacy using a computer vision-assisted lateral flow assay for influenza and SARS-CoV-2 detection.

Lateral flow assays (LFAs) have emerged as indispensable tools for point-of-care testing during the pandemic era. However, the interpretation of results through unassisted visual inspection by untrained individuals poses inherent limitations. In our study, we propose a novel approach that combines computer vision (CV) and lightweight machine learning (ML) to overcome these limitations and significantly enhance the performance of LFAs. By incorporating CV-assisted analysis into the LFA assay, we achieved a remarkable three-fold improvement in analytical sensitivity for detecting Influenza A and for SARS-CoV-2 detection. The obtained R2 values reached approximately 0.95, respectively, demonstrating the effectiveness of our approach. Moreover, the integration of CV techniques with LFAs resulted in a substantial amplification of the colorimetric signal specifically for COVID-19 positive patient samples. Our proposed approach, which incorporates a simple machine learning algorithm, provides substantial enhancements in assay sensitivity, improving diagnostic efficacy and accessibility of point-of-care testing without requiring significant additional resources. Moreover, the simplicity of the machine learning algorithm enables its standalone use on a mobile phone, further enhancing its practicality for point-of-care testing.

Epidemiology, treatment patterns, and disease burden of cytomegalovirus in hematopoietic cell transplant recipients in selected countries outside of Europe and North America: A systematic review.

BACKGROUND: Cytomegalovirus (CMV) disease impacts morbidity and mortality in hematopoietic cell transplant (HCT) recipients. This systematic review summarized data on the epidemiology, management, and burden of CMV post-HCT outside of Europe and North America. METHODS: The MEDLINE, Embase, and Cochrane databases were searched for observational studies and treatment guidelines in HCT recipients across 15 selected countries from Asia-Pacific, Latin America, and Middle East (search period: 1 January 2011-17 September 2021). Outcomes included incidence of CMV infection/disease, recurrence, risk factors, CMV-related mortality, treatments, refractory, resistant CMV, and burden. RESULTS: Of 2708 references identified, 68 were eligible (67 studies and one guideline; 45/67 studies specific to adult allogeneic HCT recipients). The rates of CMV infection and disease within 1 year of allogeneic HCT were 24.9%-61.2% (23 studies) and 2.9%-15.7% (10 studies), respectively. Recurrence occurred in 19.8%-37.9% of cases (11 studies). Up to 10% of HCT recipients died of CMV-related causes. In all countries, first-line treatment for CMV infection/disease involved intravenous ganciclovir or valganciclovir. Conventional treatments were associated with serious adverse events such as myelosuppression (10.0%) or neutropenia only (30.0%, 39.8%) and nephrotoxicity (11.0%) (three studies), frequently leading to treatment discontinuation (up to 13.6%). Refractory CMV was reported in 2.9%, 13.0%, and 28.9% of treated patients (three studies) with resistant CMV diagnosed in 0%-10% of recipients (five studies). Patient-reported outcomes and economic data were scarce. CONCLUSION: The incidence of CMV infection and disease post-HCT is high outside of North America and Europe. CMV resistance and toxicity highlight a major unmet need with current conventional treatments.

Intra-host diversity of drug-resistant cytomegalovirus: A case report of cytomegalovirus infection after allogeneic hematopoietic cell transplantation.

Cytomegalovirus (CMV) is a major infectious agent causing severe complications in allogeneic hematopoietic cell transplantation (HCT) recipients, thereby warranting the need for aggressive preemptive or targeted antiviral therapy. However, prolonged or repeated use of antiviral agents, such as ganciclovir (GCV), foscarnet (FOS), and cidofovir (CDV), can result in drug-resistant CMV infection, posing challenges to successful outcomes. Here, we report a case of a patient with acute myeloid leukemia and drug-resistant CMV infection who presented with persistent CMV DNAemia, colitis, pneumonia, and encephalitis. An intra-host diversity of UL97 and UL54 mutations were detected through the genotypic resistance testing conducted on two blood samples (D+199 and D+224) and a cerebrospinal fluid (CSF) specimen (D+260) collected from the patient. UL97 L595W/L595F and L595W mutations were detected in the blood and CSF samples, respectively, that conferred GCV resistance. UL54 F412L mutation detected in all three samples conferred GCV/CDV resistance. However, the V787L mutation of UL54, conferring GCV/FOS resistance, was observed only in the D+224 blood sample. Despite combination therapy with FOS and high dose GCV and adjunctive therapy with leflunomide, the patient died from CMV infection and multiple organ failure on D+279. Further data on resistant mutations and intra-host diversity of CMV should be accumulated to elucidate the antiviral resistance and related outcomes.

Prognosis Score System to Predict Survival for COVID-19 Cases: a Korean Nationwide Cohort Study.

BACKGROUND: As the COVID-19 pandemic continues, an initial risk-adapted allocation is crucial for managing medical resources and providing intensive care. OBJECTIVE: In this study, we aimed to identify factors that predict the overall survival rate for COVID-19 cases and develop a COVID-19 prognosis score (COPS) system based on these factors. In addition, disease severity and the length of hospital stay for patients with COVID-19 were analyzed. METHODS: We retrospectively analyzed a nationwide cohort of laboratory-confirmed COVID-19 cases between January and April 2020 in Korea. The cohort was split randomly into a development cohort and a validation cohort with a 2:1 ratio. In the development cohort (n=3729), we tried to identify factors associated with overall survival and develop a scoring system to predict the overall survival rate by using parameters identified by the Cox proportional hazard regression model with bootstrapping methods. In the validation cohort (n=1865), we evaluated the prediction accuracy using the area under the receiver operating characteristic curve. The score of each variable in the COPS system was rounded off following the log-scaled conversion of the adjusted hazard ratio. RESULTS: Among the 5594 patients included in this analysis, 234 (4.2%) died after receiving a COVID-19 diagnosis. In the development cohort, six parameters were significantly related to poor overall survival: older age, dementia, chronic renal failure, dyspnea, mental disturbance, and absolute lymphocyte count <1000/mm3. The following risk groups were formed: low-risk (score 0-2), intermediate-risk (score 3), high-risk (score 4), and very high-risk (score 5-7) groups. The COPS system yielded an area under the curve value of 0.918 for predicting the 14-day survival rate and 0.896 for predicting the 28-day survival rate in the validation cohort. Using the COPS system, 28-day survival rates were discriminatively estimated at 99.8%, 95.4%, 82.3%, and 55.1% in the low-risk, intermediate-risk, high-risk, and very high-risk groups, respectively, of the total cohort (P<.001). The length of hospital stay and disease severity were directly associated with overall survival (P<.001), and the hospital stay duration was significantly longer among survivors (mean 26.1, SD 10.7 days) than among nonsurvivors (mean 15.6, SD 13.3 days). CONCLUSIONS: The newly developed predictive COPS system may assist in making risk-adapted decisions for the allocation of medical resources, including intensive care, during the COVID-19 pandemic.

Characteristics and risk factors for mortality of invasive non-Aspergillus mould infections in patients with haematologic diseases: A single-centre 7-year cohort study.

Since mould-active azole prophylaxis has become a standard approach for patients with high-risk haematologic diseases, the epidemiology of invasive fungal infections (IFIs) has shifted towards non-Aspergillus moulds. It was aimed to identify the epidemiology and characteristics of non-Aspergillus invasive mould infections (NAIMIs). Proven/probable NAIMIs developed in patients with haematologic diseases were reviewed from January 2011 to August 2018 at Catholic Hematology hospital, Seoul, Korea. There were 689 patients with proven/probable invasive mould infections; of them, 46 (47 isolates) were diagnosed with NAIMIs. Fungi of the Mucorales order (n = 27, 57.4%) were the most common causative fungi, followed by Fusarium (n = 9, 19.1%). Thirty-four patients (73.9%) had neutropenia upon diagnosis of NAIMIs, and 13 (28.3%) were allogeneic stem cell transplantation recipients. The most common site of NAIMIs was the lung (n = 27, 58.7%), followed by disseminated infections (n = 8, 17.4%). There were 23.9% (n = 11) breakthrough IFIs, and 73.9% (n = 34) had co-existing bacterial or viral infections. The overall mortality at 6 and 12 weeks was 30.4% and 39.1%, respectively. Breakthrough IFIs (adjusted hazards ratio [aHR] = 1.99, 95% CI: 1.3-4.41, P = .031) and surgical treatment (aHR = 0.09, 95% CI: 0.02-0.45, P = .003) were independently associated with 6-week overall mortality. NAIMIs were not rare and occur as a complex form of infection often accompanied by breakthrough/mixed/concurrent IFIs and bacterial or viral infections. More active diagnostic efforts for NAIMIs are needed.

Evaluation of posaconazole plasma concentrations achieved with the delayed-release tablets in Korean high-risk patients with haematologic malignancy.

BACKGROUND: Posaconazole (PCZ) is a triazole approved for prophylaxis of invasive fungal infections. OBJECTIVES: Herein, the impact of clinical variables on PCZ plasma concentrations (PPCs) attained with PCZ delayed-release tablet (DRT) was investigated and compared with a historical cohort treated with PCZ oral suspension (OS). PATIENTS/METHODS: Steady-state PCZ PPCs in 513 patients with haematologic malignancy treated with PCZ-DRT were assessed and impact of variables were analysed. Also, a comparison with matched historical cohort treated with PCZ-OS was made. RESULTS: The median PPC in the PCZ-DRT group was 1,308.9 ng/mL (range: 29.8-10 455.9). Use of proton pump inhibitor (1181 vs 1344 ng/mL, P = .0337) in the AML/myelodysplastic syndrome remission induction group, diarrhoea (867 vs 1543 ng/mL, P = .0325) and gastrointestinal graft-versus-host disease (870 vs 1713 ng/mL, P = .0178) in the HSCT group were associated with lower PPCs. There was lack of evidence that hepatotoxicity was related with PCZ-DRT. Higher prevalence of UGT1A4*3 allele (33.0%) was noted compared to allele frequency in Koreans in those with PPCs < 500 mg/mL. The median PPC in the PCZ-DRT group was significantly higher than that in the PCZ-OS group (1308.9 vs 713.0 ng/mL, P < .0001). Significantly less patients had PPCs < 700 ng/mL in the PCZ-DRT group compared to the PCZ-OS group (18.7% vs 48.0%, P < .0001). CONCLUSIONS: Our study demonstrates that PCZ-DRT has enhanced absorption and bioavailability than PCZ-OS in real-world clinical settings. In addition, specific factors associated with lower PPCs should prompt consideration of therapeutic drug monitoring in patients treated with PCZ-DRT.

Epidemiology and Antifungal Susceptibility Profile of Aspergillus Species: Comparison between Environmental and Clinical Isolates from Patients with Hematologic Malignancies.

Global data on the epidemiology and susceptibility of Aspergillus are crucial in the management of invasive aspergillosis. Here, we aimed to determine the characteristics of clinical and environmental Aspergillus isolates, focusing mainly on hematologic malignancy patients. We prospectively collected all consecutive cases and clinical isolates of culture-positive proven/probable invasive aspergillosis patients from January 2016 to April 2018 and sampled the air inside and outside the hospital. Cryptic species-level identification of Aspergillus, antifungal susceptibilities, and cyp51 gene sequencing were performed, and clinical data were analyzed. This study was conducted as part of the Catholic Hematology Hospital Fungi Epidemiology (CAFÉ) study. A total of 207 proven/probable invasive aspergillosis and 102 clinical and 129 environmental Aspergillus isolates were included in this analysis. The incidence of proven/probable invasive aspergillosis was 1.3 cases/1,000 patient-days during the study period. Cryptic Aspergillus species accounted for 33.8%, with no differences in proportions between the clinical and environmental isolates. Section Nigri presented a high proportion (70.5%) of cryptic species, mainly from A. tubingensis and A. awamori: the former being dominant in environmental samples, and the latter being more common in clinical isolates (P < 0.001). Of 91 A. fumigatus isolates, azole-resistant A. fumigatus was found in 5.3% of all A. fumigatus isolates. Three isolates presented the TR34/L98H mutation of the cyp51A gene. Patients with invasive aspergillosis caused by azole-resistant A. fumigatus showed 100% all-cause mortality at 100 days. This study demonstrates the significant portion of cryptic Aspergillus species and clinical implications of azole resistance and underscores the comparison between clinical and environmental isolates.

Reactivation and dynamics of cytomegalovirus and Epstein-Barr virus after rabbit antithymocyte globulin and cyclosporine for aplastic anemia.

OBJECTIVES: This study aimed to identify the natural course of cytomegalovirus (CMV)/Epstein-Barr virus (EBV) after rabbit antithymocyte globulin and cyclosporine (rATG-CsA) for aplastic anemia (AA). METHODS: In 113 prospectively observed AA patients treated with rATG-CsA, the CMV/EBV cohort was classified into two groups by baseline viremic status: no viremia (CMV-G1, n = 112; EBV-G1, n = 98) and the presence of viremia (CMV-G2, n = 1; EBV-G2, n = 13). RESULTS: In CMV-G1, the mean CMV load increased up to 3 months but was completely resolved from 6 months. The mean EBV load of EBV-G1 showed a peak at 1 month and then gradually decreased over time but remained detectable throughout the observation period. EBV-G2 showed fluctuating EBV dynamics. With reactivation rates of 38.4% in CMV-G1 and 62.2% in EBV-G1, a longer time to rATG-CsA from diagnosis and a lower absolute lymphocyte count at 1 month from rATG-CsA were significantly associated with CMV and EBV reactivation, respectively. The mean peak CMV and EBV loads of patients with CMV-related (3.5%) and EBV-related (0.9%) diseases were evidently higher than those of the remaining patients without CMV and EBV diseases in the respective cohort. CONCLUSION: Considering frequent reactivation and distinct courses of CMV/EBV, virologic surveillance is recommended after rATG-CsA for AA.

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 identification of sepsis-causing Gram-negative pathogens from the plasma of infected blood.

Early and accurate detection of bacterial pathogens in the blood is the most crucial step for sepsis management. Gram-negative bacteria are the most common organisms causing severe sepsis and responsible for high morbidity and mortality. We aimed to develop a method for rapid multiplex identification of clinically important Gram-negative pathogens and also validated whether our system can identify Gram-negative pathogens with the cell-free plasm DNA from infected blood. We designed five MLPA probe sets targeting the genes specific to major Gram-negative pathogens (uidA and lacY for E. coli, ompA for A. baumannii, phoE for K. pneumoniae, and ecfX for P. aeruginosa) and one set targeting the CTX-M group 1 to identify the ESBL producing Gram-negative pathogens. All six target-specific peaks were clearly separated without any non-specific peaks in a multiplex reaction condition. The minimum detection limit was 100 fg of pathogen DNA. When we tested 28 Gram-negative clinical isolates, all of them were successfully identified without any non-specific peaks. To evaluate the clinical applicability, we tested seven blood samples from febrile patients. Three blood culture positive cases showed E. coli specific peaks, while no peak was detected in the other four culture negative samples. This technology can be useful for detection of major sepsis-causing, drug-resistant Gram-negative pathogens and also the major ESBL producing Gram-negatives from the blood of sepsis patients in a clinical setting. This system can help early initiation of effective antimicrobial treatment against Gram-negative pathogens for sepsis patients, which is very crucial for better treatment outcomes.

Risk factors and clinical outcomes of breakthrough yeast bloodstream infections in patients with hematological malignancies in the era of newer antifungal agents.

Although yeast bloodstream infections (BSIs) are increasingly being reported in patients with hematological malignancies undergoing antifungal therapy, clinical information regarding breakthrough infections is scarce. The aim of this study was to determine the risk factors for and clinical outcomes of breakthrough yeast BSIs in patients with hematological malignancies in the era of newer antifungal agents. Between 2011 and 2014, all consecutive patients with hematological malignancies who developed yeast BSIs were included in a case-control study wherein breakthrough infections (cases) and de novo infections (controls) were compared. Of 49 patients with yeast BSIs, 21 (43%) met the criteria for breakthrough infections. The proportions of Candida krusei and Candida tropicalis in the cases and controls were significantly different (32% [7/22] vs. 3% [1/29], P = .015; 5% [1/22] vs. 38% [11/29], P = .007, respectively). Acute leukemia, presence of a central venous catheter and neutropenia in the 3 days prior to BSI were significant risk factors for breakthrough infections. Six-week mortality rates was 33% [7/21] in the cases and 43% [12/28] in the controls (P = .564). Refractory neutropenia and the Pitt bacteremia score were independent predictors of 6-week mortality. In conclusion, breakthrough infections accounted for a significant proportion of yeast BSIs in patients with hematological malignancies. However, these infections did not increase the risk of death by themselves. Our results suggest that current clinical management of breakthrough yeast BSIs, which includes switching to a different antifungal class and prompt catheter removal is reasonable.

Measurement of Teicoplanin Concentration With Liquid Chromatography-Tandem Mass Spectrometry Method Demonstrates the Usefulness of Therapeutic Drug Monitoring in Hematologic Patient Populations.

BACKGROUND: Teicoplanin is a glycopeptide antibiotic that has become increasingly popular with the spread of methicillin-resistant Staphylococcus aureus. The aim of the study was to develop and validate an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for teicoplanin, and analyze trough teicoplanin concentrations achieved in patients with hematological diseases. METHODS: The UHPLC-MS/MS method for teicoplanin was developed, validated, and applied in a retrospective analysis of trough plasma teicoplanin concentrations from 305 patients receiving standard dose, and 17 patients receiving therapeutic drug monitoring (TDM)-guided individualized dose. RESULTS: The linear range was 3.9-52.9 mg/L. The imprecision was less than 12%, the limits of detection and quantification were less than 0.13 and 0.72 mg/L, respectively. The sample carry-over and ion suppression were insignificant. In the standard dose group, the median teicoplanin concentrations were 7.5 mg/L (days 3-5) and 8.9 mg/L (on days 6-8); and the proportion of trough levels achieving ≥10 mg/L was 20% (days 3-5) and 38% (days 6-8), respectively. In the TDM-guided individualized dose group, median teicoplanin concentration was higher (16.9 mg/L), and the proportion of trough levels ≥10 mg/L was also higher (77%) when compared with the standard dose group. CONCLUSIONS: Based on these results, the present UHPLC-MS/MS method can be considered suitable for routine TDM of teicoplanin. Also, based on the insufficient trough teicoplanin concentrations achieved with standard dose regimen, and the higher trough teicoplanin concentrations achieved with TDM-guided individualized dose regimen, this study highlights the importance of TDM of teicoplanin, especially in high-risk patient groups.

TR34/L98H Mutation in CYP51A Gene in Aspergillus fumigatus Clinical Isolates During Posaconazole Prophylaxis: First Case in Korea.

Azole resistance in Aspergillus fumigatus is an emerging problem, especially in immunocompromised patients. It has been reported worldwide, including in Asia, but has not yet been reported in Korea. Here, we report a case of invasive pulmonary aspergillosis (IPA) caused by azole-resistant A. fumigatus that developed in a hematopoietic stem cell transplantation recipient during posaconazole prophylaxis for immunosuppressive therapy of graft-versus-host diseases. We identified TR34/L98H/S297T/F495L mutation in the CYP51A gene of A. fumigatus clinical isolate obtained from bronchial washing fluid. Minimal inhibitory concentrations for itraconazole, voriconazole, and posaconazole were > 16, 1, and 4 µg/mL, respectively. While IPA improved partially under voriconazole treatment, the patient died from carbapenemase-producing Klebsiella pneumoniae bacteremia. Further epidemiological surveillance studies are warranted.

Epidemiology and Risk Factors for Invasive Fungal Diseases among Allogeneic Hematopoietic Stem Cell Transplant Recipients in Korea: Results of "RISK" Study.

Incidence, epidemiology, and risk factors of invasive fungal diseases (IFDs) in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients can vary from different cohorts and countries. Therefore, we performed a nationwide study to establish a proper antifungal prophylaxis strategies based on risk stratifications of IFDs after all-HSCT in Korea (RISK study). This was a multicenter, retrospective, and observational study in Korea. All consecutive adult patients who received allo-HSCT in 2013 were included. The 12-month cumulative incidence of proven/probable IFDs (PP-IFDs) was calculated during the early (days 0 to 40), late (days 41 to 100), and very late (days 101 to 365) phases after allo-HSCT. Cox proportional hazard regression analysis was performed to identify risk factors for PP-IFDs at each phase. A total 521 allo-HSCT cases in 518 patients were analyzed. Overall cumulative incidence of PP-IFDs were 4.09% (95% confidence interval [CI], 2.38 to 5.81), 7.38% (95% CI, 5.09 to 9.67), and 15.36% (95% CI, 12.04 to 18.68) at the early, late and very phases, respectively. In multiple Cox regression analysis, variables were associated with PP-IFDs in each period were identified. Variables associated with early phase include underlying pulmonary diseases, underlying nonmalignant stable or chronic disease at allo-HSCT, unrelated or family mismatched donor, and prolonged neutropenia. Variables associated with the late phase include high ferritin level at the time point of allo-HSCT, use of secondary immunosuppressive agents due to refractory graft-versus-host disease (GVHD), and cytomegalovirus reactivation. For the very late phase, variables were secondary neutropenia, severe chronic GVHD, and use of TNF-alpha inhibitor for refractory GVHD. This study revealed the high cumulative incidence of IFDs in Korean allo-HSCT recipients, which have distinct risk factors in each phase after allo-HSCT. Our findings indicate that tailored antifungal prophylaxis is necessary for high-risk patients. Clinicians should consider using mold-active antifungal prophylaxis in allo-HSCT recipients who have high risks at different treatment period.

Breakthrough invasive fungal diseases during voriconazole treatment for aspergillosis: A 5-year retrospective cohort study.

Breakthrough invasive fungal diseases (bIFDs) during voriconazole treatment are concerning, as they are associated with high rates of mortality and pathogen distribution. To evaluate the prevalence, incidence, patient characteristics, including IFD events, and overall mortality of bIFDs during voriconazole treatment for invasive aspergillosis (IA). We retrospectively analyzed the medical records of consecutive patients who had undergone voriconazole treatment for IA and who had bIFD events between January 2011 and December 2015. Eleven bIFD events occurred in 9 patients. The prevalence and incidence of bIFDs were 2.25% (9/368) and 0.22 cases per year, respectively. Overall mortality was 44.4% (4/9). The severity of the illness and persistence of immunodeficiency, mixed infection, and low concentration of the treatment drug at the site of infection were identified as possible causes of bIFDs. Seven of 11 events (63.6%) required continued voriconazole treatment with drug level monitoring. In 4 (36.3%) cases, the treatment was changed to liposomal amphotericin B. Two cases resulted in surgical resection (18.2%). Clinicians should be aware that bIFDs during voriconazole treatment for IA can occur, and active therapeutic approaches are required in these cases.

Multiplex identification of drug-resistant Gram-positive pathogens using stuffer-free MLPA system.

Early detection of pathogens from blood and identification of their drug resistance are essential for sepsis management. However, conventional culture-based methods require relatively longer time to identify drug-resistant pathogens, which delays therapeutic decisions. For precise multiplex detection of drug-resistant Gram-positive pathogens, we developed a method by using stuffer-free multiplex ligation-dependent probe amplification (MLPA) coupled with high-resolution CE single-strand conformation polymorphisms (CE-SSCP) system. We designed three probe sets for genes specific to Gram-positive species (Staphylococcus aureus: nuc, Enterococcus faecium: sodA, and Streptococcus pneumoniae: lytA) and two sets for genes associated with drug resistance (mecA and vanA) to discriminate major Gram-positive pathogens with the resistance. A total of 94 different strains (34 reference strains and 60 clinical isolates) were used to validate this method and strain-specific peaks were successfully observed for all the strains. To improve sensitivity of the method, a target-specific preamplification step was introduced and, consequently, the sensitivity increased from 10 pg to 100 fg. We also reduced a total assay time to 8 h by optimizing hybridization time without compromising test sensitivity. Taken together, our multiplex detection system can improve detection of drug-resistant Gram-positive pathogens from sepsis patients' blood.

Immunomodulatory effect of mesenchymal stem cells on the immune response of macrophages stimulated by Aspergillus fumigatus conidia.

Mesenchymal stem cells (MSCs) are known to exert potent immunosuppression and anti-inflammatory effects. There is growing interest in their use for immunotherapy for controlling inflammation as well as acute organ injury. However, there are few reports regarding MSC's immunomodulatory effects in the settings of fungal infection. In this study, we attempted to examine the immunomodulatory effects of MSCs in response to Aspergillus fumigatus We measured the cytokine response of murine MSCs on the immune response of murine macrophages (J774A.1 cells) evoked by A. fumigatus conidia. In addition, we evaluated the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the MSC-related cytokine response and fungal growth. As a results, after conidia stimulation, tumor necrosis factor (TNF)-α was down-regulated and interleukin (IL)-10 was up-regulated in MSC-treated J774A.1 cells when compared to J774A.1 cells alone. In addition, fungal growth was reduced in MSC-treated J774A.1 cells when compared to J774A.1 cells, which recovered by GM-CSF. However, the effect of MSCs on the cytokine response was not reversed by GM-CSF. NF-κB translocation decreased in MSC-treated J774A.1 cells compared to J774A.1 cells alone. In conclusion, MSCs demonstrate immunomodulatory properties in both aspects of cytokines and fungal growth. The anti-inflammatory effect of MSCs with regard to cytokine response might be associated with decreased NF-κB translocation, and is not reversed by GM-CSF.

Pseudozyma aphidis fungaemia with invasive fungal pneumonia in a patient with acute myeloid leukaemia: case report and literature review.

Pseudozyma species rarely cause invasive diseases in humans, which are usually isolated from plants. There have been anecdotal reports regarding Pseudozyma species infections in patients with underlying diseases or in neonates. However, clinical data and the pathogenicity in humans are still insufficient. We experienced a case of Pseudozyma aphidis fungaemia with invasive fungal pneumonia that developed during reinduction chemotherapy in a 51-year-old male with acute myeloid leukaemia (AML). P. aphidis was suspected based on the morphology of the yeast isolated from the blood and was confirmed via rDNA gene sequencing analysis. The patient successfully underwent stem cell transplantation with continuing antifungal treatment and finally completely recovered from both the AML and infectious complications. Here, we report a case of P. aphidis infection that developed during neutropenia in an AML patient and review the global literature.