Applying host disease status biomarkers to therapeutic response monitoring in invasive aspergillosis patients.

One critical factor impeding successful management of invasive aspergillosis (IA) is the lack of reliable biomarkers to assess therapeutic response. We hypothesized that changes in certain host biomarkers reflect the nature of infection status and disease progression. Upon primary IA diagnosis, these disease status biomarkers can be monitored to track response to antifungal therapy and provide early markers that prognosticate likelihood of response. Herein, we analyzed serum levels of three prominent host disease status biomarkers C-reactive protein (CRP), haptoglobin (Hp), and annexin A1 (ANXA1) in IA patients during antifungal therapy. A total of 81 serial serum samples were collected at five or six different time points relative to IA diagnosis from 15 probable IA patients (10 acute leukemia [AL] and five hematopoietic stem cell transplantation [HSCT]). Of note, different biomarker profiles were observed in AL and HSCT patients, as not only levels of markers were significantly lower in HSCT patients but also more prominent interconnections among markers were observed in AL patients. Using a composite evaluation, patients were categorized as responders, nonresponders, and stable cases at last specimen. For AL responders, typical biomarker profiles were high initially but rapidly decreased for CRP and Hp post antifungal therapy, while low initial ANXA1 values were restored to normal levels after treatment. In contrast, CRP and Hp were persistently elevated whilst ANXA1 remained low throughout therapy in AL non-responders. As a pilot proof-of-concept study, our work demonstrates the great potential of using host biomarkers to monitor early therapeutic response in leukemia patients.

Blood Aspergillus RNA is a promising alternative biomarker for invasive aspergillosis.

A critical challenge for the successful application of antifungal therapies for invasive aspergillosis (IA) is a lack of reliable biomarkers to assess early treatment response. Patients with proven or probable IA were prospectively enrolled, and serial blood samples were collected at 8 specified time points during 12-week antifungal therapy. Total nucleic acid was extracted from 2.5 ml blood and tested for Aspergillus-specific RNA by a pan-Aspergillus real-time nucleic acid sequence-based amplification (NASBA) assay. Serum 1, 3-ß-D-glucan (BG) and galactomannan (GM) were measured in parallel. Clinical outcome was evaluated at 6 and 12 weeks. Overall, 48/328 (14.6%) blood samples from 29/46 (63%) patients had positive NASBA detection at baseline and/or some point during the study. Positive NASBA results during the first 4 and 6 weeks of treatment are significantly associated with the 12-week outcome. Blood RNA load change during weeks 4-6 may be informative to predict outcome at 12 weeks. While independent of serum GM, the kinetic change of circulating Aspergillus RNA appears to be well correlated with that of BG on some patient individuals. Monitoring blood Aspergillus RNA during the first 4-6 weeks of antifungal treatment may help assess therapeutic response. Combination of circulating Aspergillus RNA and BG may be a useful adjunct to assess response.

Carbohydrate-derived fulvic acid is a highly promising topical agent to enhance healing of wounds infected with drug-resistant pathogens.

BACKGROUND: This work was intended as a proof-of-principle study to help establish carbohydrate-derived fulvic acid (CHD-FA) as a safe and effective agent that can be deployed to prevent the onset of drug-resistant bacterial and fungal infections in military and civilian personnel experiencing traumatic wound. METHODS: Minimum inhibitory concentrations for CHD-FA were established on a total of 500 clinical isolates representing wound-associated drug-sensitive and drug-resistant bacterial and fungal pathogens. The efficacy of early use of CHD-FA to enhance healing of wounds infected with methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa was evaluated in an in vivo rat model. RESULTS: CHD-FA showed strong activity against a variety of bacterial and fungal pathogens with minimum inhibitory concentration values equal or less than 0.5%. Compared with infected but untreated wounds, improved wound healing upon CHD-FA treatment was observed in both infection models, demonstrated by wound surface area measurement, histopathologic examination, and expression profiling of wound healing genes. Up-regulation of proinflammatory cytokine interleukin 6 (IL-6) at Day 3 after infection was significantly dampened at Days 6 and 10 in the CHD-FA-treated wounds in both infection models, displaying an improved and accelerated wound healing. CONCLUSION: CHD-FA is a promising topical remedy for drug-resistant wound infections. It accelerated the healing process of wounds infected with methicillin-resistant S. aureus and multidrug-resistant P. aeruginosa in rats, which is linked to both its antimicrobial and anti-inflammatory properties.

Molecular evaluation of the plasma membrane proton pump from Aspergillus fumigatus.

The gene encoding the plasma membrane proton pump (H+ -ATPase) of Aspergillus fumigatus, PMA1, was characterized from A. fumigatus strain NIH 5233 and clinical isolate H11-20. An open reading frame of 3,109 nucleotides with two introns near the N terminus predicts a protein consisting of 989 amino acids with a molecular mass of approximately 108 kDa. The predicted A. fumigatus enzyme is 89 and 51% identical to H+ - ATPases of Aspergillus nidulans and Saccharomyces cerevisiae, respectively. The A. fumigatus PMA1 is a typical member of the P-type ATPase family that contains 10 predicted transmembrane segments and conserved sequence motifs TGES, CSDKTGT, MLTGD, and GDGVN within the catalytic region. The enzyme represents 2% of the total plasma membrane protein, and it is characteristically inhibited by orthovanadate, with a 50% inhibitory concentration of approximately 1.8 microM. H+ -ATPases from Aspergillus spp. contain a highly acidic insertion region of 60 amino acids between transmembrane segments 2 and 3, which was confirmed for the membrane-assembled enzyme with a peptide-derived antibody. An increasing A. fumigatus PMA1 copy number confers enhanced growth in low-pH medium, consistent with its role as a proton pump. These results provide support for the development of the A. fumigatus H+ -ATPase as a potential drug discovery target.