Dataset Information

Rapid Detection and Differentiation of Clinically Relevant Candida Species Simultaneously from Blood Culture by Use of a Novel Signal Amplification Approach.

ABSTRACT: Fungal bloodstream infections are a significant problem in the United States, with an attributable mortality rate of up to 40%. An early diagnosis to direct appropriate therapy has been shown to be critical to reduce mortality rates. Conventional phenotypic methods for fungal detection take several days, which is often too late to impact outcomes. Herein, we describe a cost-effective multiplex assay platform for the rapid detection and differentiation of major clinically relevant Candida species directly from blood culture. This approach utilizes a novel biotin-labeled polymer-mediated signal amplification process combined with targeting rRNA to exploit phylogenetic differences for sensitive and unambiguous species identification; this assay detects seven pathogenic Candida species (C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, C. lusitaniae, and C. guilliermondii) simultaneously with very high specificity to the species level in less than 80 min with the limits of detection at 1 × 103 to 10 × 103 CFU/ml or as few as 50 CFU per assay. The performance of the described assay was verified with 67 clinical samples (including mixed multiple-species infections as well), with an overall 100% agreement with matrix-assisted laser desorption ionization (MALDI) mass spectrometry-based reference results. By providing a species identity rapidly, the clinician is aided with information that may direct appropriate therapy sooner and more accurately than current approaches, including PCR-based tests.

SUBMITTER: Ao W

PROVIDER: S-EPMC5744229 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Rapid Detection and Differentiation of Clinically Relevant Candida Species Simultaneously from Blood Culture by Use of a Novel Signal Amplification Approach.

Ao Wanyuan W Klonoski Joshua J Berlinghoff Eric E Jensen Jordan J Afroz Taliman T Munns Denton D Lindsey Wes W Denys Gerald G Jenison Robert R

Journal of clinical microbiology 20171226 1

Fungal bloodstream infections are a significant problem in the United States, with an attributable mortality rate of up to 40%. An early diagnosis to direct appropriate therapy has been shown to be critical to reduce mortality rates. Conventional phenotypic methods for fungal detection take several days, which is often too late to impact outcomes. Herein, we describe a cost-effective multiplex assay platform for the rapid detection and differentiation of major clinically relevant <i>Candida</i> ...[more]

PMID: 29046411

Similar Datasets

Project description:Enhanced quantitative urine culture (EQUC) detects live microorganisms in the vast majority of urine specimens reported as "no growth" by the standard urine culture protocol. Here, we evaluated an expanded set of EQUC conditions (expanded-spectrum EQUC) to identify an optimal version that provides a more complete description of uropathogens in women experiencing urinary tract infection (UTI)-like symptoms. One hundred fifty adult urogynecology patient-participants were characterized using a self-completed validated UTI symptom assessment (UTISA) questionnaire and asked "Do you feel you have a UTI?" Women responding negatively were recruited into the no-UTI cohort, while women responding affirmatively were recruited into the UTI cohort; the latter cohort was reassessed with the UTISA questionnaire 3 to 7 days later. Baseline catheterized urine samples were plated using both standard urine culture and expanded-spectrum EQUC protocols: standard urine culture inoculated at 1 ?l onto 2 agars incubated aerobically; expanded-spectrum EQUC inoculated at three different volumes of urine onto 7 combinations of agars and environments. Compared to expanded-spectrum EQUC, standard urine culture missed 67% of uropathogens overall and 50% in participants with severe urinary symptoms. Thirty-six percent of participants with missed uropathogens reported no symptom resolution after treatment by standard urine culture results. Optimal detection of uropathogens could be achieved using the following: 100 ?l of urine plated onto blood (blood agar plate [BAP]), colistin-nalidixic acid (CNA), and MacConkey agars in 5% CO2 for 48 h. This streamlined EQUC protocol achieved 84% uropathogen detection relative to 33% detection by standard urine culture. The streamlined EQUC protocol improves detection of uropathogens that are likely relevant for symptomatic women, giving clinicians the opportunity to receive additional information not currently reported using standard urine culture techniques.

Project description:BackgroundFungal bloodstream infections (BSI) may be serious and are associated with drastic rise in mortality and health care costs. Candida spp. are the predominant etiological agent of fungal sepsis. The prompt and species-level identification of Candida may influence patient outcome and survival. The aim of this study was to develop and evaluate the CanTub-simplex PCR assay coupled with Tm calling and subsequent high resolution melting (HRM) analysis to barcode seven clinically relevant Candida species.MethodsEfficiency, coefficient of correlation and the limit of reliable detection were estimated on purified Candida EDTA-whole blood (WB) reference panels seeded with Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei, Candida guilliermondii, Candida dubliniensis cells in a 6-log range. Discriminatory power was measured on EDTA-WB clinical panels on three different PCR platforms; LightCycler®96, LightCycler® Nano, LightCycler® 2.0. Inter- and intra assay consistencies were also calculated.ResultsThe limit of reliable detection proved to be 0.2-2 genomic equivalent and the method was reliable on broad concentration ranges (106-10 CFU) providing distinctive melting peaks and characteristic HRM curves. The diagnostic accuracy of the discrimination proved to be the best on Roche LightCycler®2.0 platform. Repeatability was tested and proved to be % C.V.: 0.14 ± 0.06 on reference- and % C.V.: 0.14 ± 0.02 on clinical-plates accounting for a very high accuracy. Reproducibility was % C.V.: 0.11 between reference- and % C.V.: 0.12between clinical-panels which is highly acceptable.ConclusionOur assay demonstrates recent advances on Tm calling and HRM analysis for the molecular identification of relevant Candida species. This unique, simplex PCR assay may be capable to outperform conventional phenotypic methods by reducing time and providing accurate and reliable results directly from blood (2 h) or from whole blood culture bottles (12-24 h).

Project description:BackgroundThe genus Candida includes about 200 different species, but only a few are able to produce disease in humans. The species responsible for the highest proportion of human infections is Candida albicans. However, in the last two decades there has been an increase in the proportion of infections caused by other Candida species, including C. glabrata (Nakaseomyces glabrata), C. parapsilosis, C. tropicalis, C. krusei (Pichia kudriavzevi) and more recently C. auris. Decolonisation of patients has been used as an infection control strategy for bacterial infections, but information about decolonisation products used in clinical practice for Candida and other fungal pathogens is limited. Compounds with antimicrobial activity, such as triclosan (TR), boric acid (BA) and zinc oxide (ZO), are mainly used in personal care products. These products can be used for long periods of time without an abrasive skin effect and are a possible alternative for patient decolonisation in healthcare settings.ObjectiveThe aim of this study was to evaluate the antifungal activity of boric acid (BA), triclosan (TR) and zinc oxide (ZO), individually and combined, against clinically relevant Candida species.Materials and methodsCompounds to be screened for antifungal activity were evaluated at different concentrations, alone, and combined, using a well diffusion assay. The statistical evaluation was performed using analysis of variance (ANOVA) and a post hoc analysis using the multiple comparisons method.ResultsIndividually, BA and TR showed antifungal activity against all Candida species evaluated but ZO did not show any antifungal activity. Mixtures of BA [5%]-TR [0.2%]; BA [5%]-TR [0.3%]; BA [5%]-TR [0.2%]-ZO [8.6%]; and BA [5%]-TR [0.2%]-ZO [25%] yielded the highest antifungal activity. An increased antifungal effect was observed in some mixtures when compared with individual compounds.ConclusionsWe demonstrated antifungal activity of BA and TR against multiple Candida species, including against a clade of the emerging healthcare-associated pathogen C. auris. Additionally, this study shows enhancement of the antifungal effect and no antagonism among the mixtures of these compounds. Further research is needed to determine whether these compounds can reduce the burden of Candida on skin.

Dataset Information

Rapid Detection and Differentiation of Clinically Relevant Candida Species Simultaneously from Blood Culture by Use of a Novel Signal Amplification Approach.

Publications

Rapid Detection and Differentiation of Clinically Relevant Candida Species Simultaneously from Blood Culture by Use of a Novel Signal Amplification Approach.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets