Testing the performance of a prototype lateral flow device using bronchoalveolar lavage fluid for the diagnosis of invasive pulmonary aspergillosis in high‐risk patients

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141729/1/myc12694_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141729/2/myc12694.pd

Current Trends of Infectious Complications following Hematopoietic Stem Cell Transplantation in a Single Center

This study was to analyze the infectious complications after hematopoietic stem cell transplantation (HSCT) according to the recent changes of HSCT. Medical records of 379 adult patients who underwent HSCT consecutively at Catholic HSCT Center from January 2001 to December 2002 were reviewed retrospectively. Allogeneic HSCT accounted for 75.7% (287/379) and autologous HSCT for 24.3% (92/379). During pre-engraftment period, bacterial infection was predominant, and E. coli was still the most common organism. After engraftment, viral infection was predominant. The incidence of invasive fungal infection showed bimodal distribution with peak correlated with neutropenia and graft-versus-host disease (GVHD). The overall mortality and infection-related mortality rates according to 3 periods were as follows; during pre-engraftment, 3.16% (12/379) and 1.8% (7/379); during midrecovery period, 7.9% (29/367) and 4.1% (15/367); during late-recovery period, 26.9% (91/338), and 15.9% (54/338). Risk factors for infection-related mortality were as follows; during pre-engraftment period, fungal infection and septic shock; during the mid-recovery period, hemorrhagic cystitis and delayed engraftment; during the late-recovery period, fungal infection, chronic GVHD, and relapse. In conclusion, infection was still one of the main complications after HSCT and highly contributes to mortality. The early diagnosis and the effective vaccination strategy are needed for control of infections

Levels of (1→3)-β-D-glucan, Candida mannan and Candida DNA in serum samples of pediatric cancer patients colonized with Candida species

<p>Abstract</p> <p>Background</p> <p>Surveillance cultures may be helpful in identifying patients at increased risk of developing invasive candidiasis. However, only scant information exists on the effect of <it>Candida </it>colonization on serum levels of diagnostic biomarkers. This prospective surveillance study determined the extent of <it>Candida </it>colonization among pediatric cancer patients and its possible impact on serum levels of (1-3)-β-D-glucan (BDG), <it>Candida </it>mannan and <it>Candida </it>DNA.</p> <p>Methods</p> <p>A total of 1075 swabs originating from oropharynx (n = 294), nostrils (n = 600), rectum (n = 28), groin (n = 50), ear (n = 54), and axilla (n = 49) of 63 pediatric cancer patients were cultured for the isolation of <it>Candida </it>spp. Patients yielding <it>Candida </it>spp. from any sites were considered as colonized. Serum samples were collected from patients at the time of first surveillance culture for detection of BDG by Fungitell kit and <it>Candida </it>mannan by Platelia <it>Candida </it>Ag. <it>Candida </it>DNA was detected by using panfungal primers and identification was carried out by using species-specific primers and DNA sequencing.</p> <p>Results</p> <p>Seventy-five (7.6%) swab cultures from 35 (55.5%) patients yielded <it>Candida </it>spp. These isolates included <it>C. albicans </it>(n = 62), <it>C. dubliniensis </it>(n = 8), <it>C. glabrata </it>and <it>C. tropicalis </it>(n = 2 each) and <it>C. krusei </it>(n = 1). Eleven patients were colonized at three or more sites. Eight of 36 serum samples from 6 colonized patients yielded BDG values higher than the currently recommended cut-off value of ≥80 pg/ml. However, none of the serum samples yielded <it>Candida </it>mannan levels ≥0.5 ng/ml and PCR test for <it>Candida </it>DNA was also negative in all the serum samples of colonized patients. During the study period, only two colonized patients subsequently developed candidemia due to <it>C. tropicalis</it>. Besides positive blood cultures, <it>C. tropicalis </it>DNA, BDG and <it>Candida </it>mannan were also detected in serum samples of both the patients.</p> <p>Conclusions</p> <p>The present study demonstrates that while mucosal colonization with <it>Candida </it>species in pediatric cancer patients is common, it does not give rise to diagnostically significant levels of <it>Candida </it>mannan or <it>Candida </it>DNA in serum specimens. However, BDG values may be higher than the cut-off value in some pediatric patients without clinical evidence of invasive <it>Candida </it>infection. The study suggests the utility of <it>Candida </it>mannan or <it>Candida </it>DNA in the diagnosis of invasive candidiasis, however, the BDG levels in pediatric cancer subjects should be interpreted with caution.</p

Bacterial SBP56 identified as a Cu-dependent methanethiol oxidase widely distributed in the biosphere

Oxidation of methanethiol (MT) is a significant step in the sulfur cycle. MT is an intermediate of metabolism of globally significant organosulfur compounds including dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS), which have key roles in marine carbon and sulfur cycling. In aerobic bacteria, MT is degraded by a MT oxidase (MTO). The enzymatic and genetic basis of MT oxidation have remained poorly characterized. Here, we identify for the first time the MTO enzyme and its encoding gene (mtoX) in the DMS-degrading bacterium Hyphomicrobium sp. VS. We show that MTO is a homotetrameric metalloenzyme that requires Cu for enzyme activity. MTO is predicted to be a soluble periplasmic enzyme and a member of a distinct clade of the Selenium-binding protein (SBP56) family for which no function has been reported. Genes orthologous to mtoX exist in many bacteria able to degrade DMS, other one-carbon compounds or DMSP, notably in the marine model organism Ruegeria pomeroyi DSS-3, a member of the Rhodobacteraceae family that is abundant in marine environments. Marker exchange mutagenesis of mtoX disrupted the ability of R. pomeroyi to metabolize MT confirming its function in this DMSP-degrading bacterium. In R. pomeroyi, transcription of mtoX was enhanced by DMSP, methylmercaptopropionate and MT. Rates of MT degradation increased after pre-incubation of the wild-type strain with MT. The detection of mtoX orthologs in diverse bacteria, environmental samples and its abundance in a range of metagenomic data sets point to this enzyme being widely distributed in the environment and having a key role in global sulfur cycling.The ISME Journal advance online publication, 24 October 2017; doi:10.1038/ismej.2017.148

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

1,3-beta-D-glucan in patients receiving intravenous amoxicillin-clavulanic acid.

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Non-culture-based diagnostics for opportunistic fungi.

Item does not contain fulltextThe value of the diagnostic markers galactomannan and 1,3-beta-D-glucan for the diagnosis of opportunistic fungal infections is reviewed in this article. Both markers have undergone clinical evaluation, and increasing insight is emerging with respect to the causes of false-negative or false-positive reactivity. These data will help design protocols in which single or multiple markers are used to identify patients who require antifungal therapy

Pseudomonas aeruginosa as a cause of 1,3-beta-D-glucan assay reactivity.

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