Multicenter Evaluation of Candida QuickFISH BC for Identification of Candida Species Directly from Blood Culture Bottles

Candida species are common causes of bloodstream infections (BSI), with high mortality. Four species cause >90% of Candida BSI: C. albicans, C. glabrata, C. parapsilosis, and C. tropicalis. Differentiation of Candida spp. is important because of differences in virulence and antimicrobial susceptibility. Candida QuickFISH BC, a multicolor, qualitative nucleic acid hybridization assay for the identification of C. albicans (green fluorescence), C. glabrata (red fluorescence), and C. parapsilosis (yellow fluorescence), was tested on Bactec and BacT/Alert blood culture bottles which signaled positive on automated blood culture devices and were positive for yeast by Gram stain at seven study sites. The results were compared to conventional identification. A total of 419 yeast-positive blood culture bottles were studied, consisting of 258 clinical samples (89 C. glabrata, 79 C. albicans, 23 C. parapsilosis, 18 C. tropicalis, and 49 other species) and 161 contrived samples inoculated with clinical isolates (40 C. glabrata, 46 C. albicans, 36 C. parapsilosis, 19 C. tropicalis, and 20 other species). A total of 415 samples contained a single fungal species, with C. glabrata (n = 129; 30.8%) being the most common isolate, followed by C. albicans (n = 125; 29.8%), C. parapsilosis (n = 59; 14.1%), C. tropicalis (n = 37; 8.8%), and C. krusei (n = 17; 4.1%). The overall agreement (with range for the three major Candida species) between the two methods was 99.3% (98.3 to 100%), with a sensitivity of 99.7% (98.3 to 100%) and a specificity of 98.0% (99.4 to 100%). This study showed that Candida QuickFISH BC is a rapid and accurate method for identifying C. albicans, C. glabrata, and C. parapsilosis, the three most common Candida species causing BSI, directly from blood culture bottles

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Isolation and Characterization of Antimicrobial Compounds in Plant Extracts against Multidrug-Resistant <i>Acinetobacter baumannii</i>

<div><p>The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant <i>Acinetobacter baumannii</i> (<i>A. baumannii</i>) is extremely limited. <i>Magnolia officinalis</i>, <i>Mahonia bealei</i>, <i>Rabdosia rubescens</i>, <i>Rosa rugosa</i>, <i>Rubus chingii</i>, <i>Scutellaria baicalensis</i>, and <i>Terminalia chebula</i> plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of <i>A. baumannii</i>. In this study, the compounds responsible for their antimicrobial activity were identified by fractionating each plant extract using high performance liquid chromatography, and determining the antimicrobial activity of each fraction against <i>A. baumannii</i>. The chemical structures of the fractions inhibiting >40% of the bacterial growth were elucidated by liquid chromatography/mass spectrometry analysis and nuclear magnetic resonance spectroscopy. The six most active compounds were identified as: ellagic acid in <i>Rosa rugosa</i>; norwogonin in <i>Scutellaria baicalensis</i>; and chebulagic acid, chebulinic acid, corilagin, and terchebulin in <i>Terminalia chebula</i>. The most potent compound was identified as norwogonin with a minimum inhibitory concentration of 128 µg/mL, and minimum bactericidal concentration of 256 µg/mL against clinically relevant strains of <i>A. baumannii</i>. Combination studies of norwogonin with ten anti-Gram negative bacterial agents demonstrated that norwogonin did not enhance the antimicrobial activity of the synthetic antibiotics chosen for this study. In conclusion, of all identified antimicrobial compounds, norwogonin was the most potent against multidrug-resistant <i>A. baumannii</i> strains. Further studies are warranted to ascertain the prophylactic and therapeutic potential of norwogonin for infections due to multidrug-resistant <i>A. baumannii</i>.</p></div

Determination of antimicrobial activity of purified compounds from plant extracts against two <i>A.</i> baumannii<i> </i> strains.

<p>Two-fold serially diluted norwogonin (<b>A</b>), terchebulin (<b>B</b>), chebulagic acid (<b>C</b>) and corilagin (<b>D</b>) suspensions were prepared in cation-adjusted Mueller-Hinton broth and mixed with an equal volume of either strain 31P or BAA-1605 suspension (5×10⁵ CFU/mL final). Bacterial growth was measured after a 16 h incubation at 37°C. The final test concentration for each compound ranged from 0.25 to 128 µg/mL for norwogonin (MIC₉₀ = 128 µg/mL), and 7.8 to 1,000 µg/mL for terchebulin (MIC₉₀ = 500 µg/mL), chebulagic acid and corilagin. • 31P and ▴ BAA-1605.</p

Dose response testing of synthetic anti-Gram negative bacterial agents in combination with norwogonin.

<p>The IC₉₀ (µg/mL) of each antibiotic either alone or in combination with 8 or 16 µg/mL norwogonin against strain 31P were determined. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0061594#s3" target="_blank">Results</a> are presented as the average IC₉₀ for two experiments each done in duplicate.</p>*<p>IC₉₀ for trimethoprim/sulfamethoxazole could not be determined as maximum inhibition remained below 90% at all concentrations tested.</p