Early Identification of Candida in Intra-abdominal Candidiasis (ICCA)

The ICCA Study (Early Identification of Candida in Intra-abdominal CAndidiasis)

Intra-abdominal candidiasis remains the first origin of invasive candidiasis in critically ill patients with a mortality up to 60%. This high mortality is partly related to delay of anti-fungal treatment administration. According to experts in the field, new diagnostic methods to rapidly detect Candida in intra-abdominal infections is mandatory because the current strategies suffer from a lack of both sensitivity and specificity.

The calscreener (SYMCEL®) is a new diagnostic tool to rapidly identify the presence of pathogens in biological samples based on micrometabolic activity detection. This technology also allows to measure the metabolic activity of pathogens.

The ICCA project will test the feasibility, the accuracy and the diagnostic performance of the calscreener on an existing biological collection of peritoneal fluid. This collection came from a cohort of critically ill patients with intra-abdominal infection which required abdominal surgery. Intra-abdominal infections consist of bacterial peritonitis and intra-abdominal candidiasis. The presence of pathogens (bacteria and yeast) is already known, the peritoneal fluid being stored after routine analysis (bacteriology / mycology).

In addition to the detection / identification of yeast will be investigated in this project, the cal screener will be used to evaluate the metabolic profile of Candida albicans in the peritoneal fluid, alone and with bacteria. This objective aims to evaluate the virulence of Candida in the peritoneal fluid from a metabolic perspective. The results will be compared to phenotypic and molecular evaluation.

Study Overview

• Status: Completed
• Conditions: Candidiasis, Invasive; Critically Ill; Candida Sepsis; Peritonitis Infectious
• Intervention / Treatment: Diagnostic test: calscreener; Other: Metabolic profile; Other: optical microscopy; Other: RTqPCR

Detailed Description

The high mortality rate of patients with intra-abdominal candidiasis infection is partly related to delay in anti-fungal treatment. The gold standard method for Candida detection remains the yeast culture on mycological media which suffers from a delayed response time (up to 5 days).

Consequently, in the routine practice, the decision to start an anti-fungal treatment is based on predictive scores such as the Peritonitis score. Whatever the score, they all suffer from a lack of sensitivity and specificity and could expose ICU patients to delayed treatment with negative impact on mortality. Once introduced and before the availability of the result of the culture, the anti-fungal can be stopped based on two serum measures of 1,3 beta D Glucan < 80 pg/ml. This strategy allows anti-fungal spare. Therefore, there is a room for improvement regarding early Candida detection and identification for the right choice of anti-fungal.

The calscreener (SYMCEL®) is a new diagnostic tool to rapidly identify the presence of pathogens in biological samples based on micrometabolic activity detection. The metabolic activity anticipates the future positive culture. To date, most of the experiments with the calscreenerTM concern bacteria. During the development phase, some experiments have been performed with Candida, mostly in vitro. Data of feasibility with clinical samples such as the peritoneal fluid are lacking. Besides, there is currently no library regarding the metabolic profile of Candida, in both albicans and non-albicans species. All in all, its routine use is currently impossible.

First results (unpublished data from our team) of metabolic activity detection in peritoneal fluid with known presence of Candida showed a time detection <1 hour. We aim to confirm these promising results using biological samples collected in an ongoing cohort study. We first need to describe the metabolic activity curves of different Candida species in order to constitute a library.

The heat production of each peritoneal fluid will be measured, and then compared considering the presence or absence of bacteria. Then, to explain the metabolic activity, a phenotypic evaluation of candida (growth and yeast-to-hyphae transition) and molecular evaluation (level of expression of virulence gene) will be performed.

• Study Type: Observational
• Enrollment (Actual): 40

Contacts and Locations

Study Locations

• France
  • Vandoeuvre les Nancy, France, 54500
    • Central Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

In the present study will be used the clinical samples issued from the biological collection of peritoneal fluid issue from the pBDG2 study. The presence of Candida of each sample is known thanks to routine analysis. According to the ethic committee, only peritoneal fluid issued from patients from the centre "NANCY" will be investigated in the ICCA STUDY.

The results obtained with the calscreener will be compared to those obtain by yeast culture to confirm the Candida detection irrespective and depending on the albicans and non-albicans species.

Lastly the delay of detection with the calscreener will be compared to the growth delay of yeast culture

Description

The criteria belong to the pBDG2 study (Peritoneal 1.3-ß-D-glucan for the Diagnosis of Intra-abdominal Candidiasis in Critically Ill Patients).

Inclusion Criteria:

• adult
• Covered by health insurance
• Admitted in ICU with intra-abdominal infection requiring abdominal surgery or percutaneous drainage

Exclusion Criteria:

• Pregnant or lactating woman
• Patient deprived of liberty after administration of juridical decision
• Patient under psychiatric care

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Retrospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

critically ill adult patients with intra-abdominal infection; The ICCA study is an ancillary study of a non-interventional prospective cohort study (the pBDG2 study, NCT03997929) The pBDG 2 study has enrolled ICU patients with intra-abdominal infection requiring abdominal surgery. During the surgery, peritoneal fluid has been collected to identify the pathogens involved and guide anti-infective therapies. After the routine analyses, the remained peritoneal fluid was stored to create a biological collection. This biological collection, in which the content of bacterias and yeasts is known, will be analysed with the calscreener.

Diagnostic test: calscreener; The calscreener (SYMCEL®) is a new diagnostic tool to rapidly identify the presence of pathogens in biological samples based on micrometabolic activity detection. All living cells produce heat by the chemical and physical processes of life; by monitoring the heat flow over time (J/s, W) a significant amount of information can be obtained regarding the biological system.; Other: Metabolic profile; The cal screener allows the measure of metabolic activity of pathogens directly from a sample (here, the peritoneal fluid). The heat production will be compared between peritoneal fluid, with or without addition of bacteria; Other: optical microscopy; To explain the metabolic activity, growth and yeast-to-hyphae transition will be analysed using optical microscopy and conventional culture; Other: RTqPCR; To explain the metabolic activity, level of expression of 5 Candida albicans virulence genes (UME6, ALS3, SFL2, HWP1 and ECE1) will be address and compared between peritoneal fluid.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Detection (Yes/No) of the presence of Candida in the peritoneal fluid	Detection by the calscreener : detection of metabolic activity > 5 µW (according to SYMCEL recommendation)	Day 1 - 3

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Delay (in hours) of detection	Delay (in hours) from the start of calscreener analysis to first detection of heat flow > 5 µW	Day 1 - 3

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heat production (Joule)	Heat production depending on the peritoneal fluid and the presence or absence of bacteria	Day 1 - 3
Candida morphology	C. albicans SC5314 strain will be inoculated in triplicate into one mL of the different peritoneal fluid, as well as control media (Sabouraud and ascitic fluid) at an optical density (OD) of 0.3 nm, corresponding to approximately 3.10^6 colonies of C. albicans per millilitre (C. albicans/mL) of media. Control wells containing only the media without C. albicans were also included on the same 24-well plate to confirm the absence of contamination. The 24-well plate will be inoculated and incubated at 37°C with shaking at 300 RPM for 24 hours. The morphology of C. albicans (yeast or pseudo-hyphae or hyphae) was observed under a light microscope at hourly intervals for the initial eight hours, followed by observations at H16 and H24.	Day 1
Candida growth	C. albicans SC5314 strain will be inoculated in triplicate into one mL of the different peritoneal fluid, as well as control media (Sabouraud and ascitic fluid) at an optical density (OD) of 0.3 nm, corresponding to approximately 3.10^6 colonies of C. albicans per millilitre (C. albicans/mL) of media. Control wells containing only the media without C. albicans were also included on the same 24-well plate to confirm the absence of contamination. The 24-well plate will be inoculated and incubated at 37°C with shaking at 300 RPM for 24 hours. C. albicans growth was assessed by inoculating 10 μL from each well onto SBD dextrose agar, and the colonies were counted after 24 hours of incubation at 37°C. To facilitate counting, 1000-fold dilutions of each inoculated well were prepared beforehand.	Day 1
Candida virulence gene expression	C. albicans inoculation in the different media followed the same protocol as for phenotypic evaluation, with an overnight culture of 24h before gene expression analysis. The five virulence genes of interest are UME6, ALS3, SFL2, HWP1 and ECE1. After the 24-hour overnight culture, the samples will be centrifuged to retain only the cell pellet. The cell pellet was then washed twice with 10 mL of phosphate-buffered saline (PBS). Subsequently, the PBS was removed, leaving behind only the cell pellet. RNA extraction will be performed using the FASTPREP® lysis technology. Reverse transcription will be performed using the QuantiTect Reverse Transcription kit from Qiagen® (Germantown, Maryland, United States) following the manufacturer's instructions. The qPCR was performed in MicroAmp Optical 96-Well Reaction Plates (Applied Biosystems) using the CFX96 Real-Time PCR System (Bio-Rad, Marnes-la Coquette, France).	Day 1

Collaborators and Investigators

• Sponsor: Central Hospital, Nancy, France
• Collaborators: SYMCEL

Study record dates

Study Major Dates

• Study Start (Actual): February 17, 2022
• Primary Completion (Actual): June 30, 2022
• Study Completion (Actual): June 22, 2023

Study Registration Dates

• First Submitted: February 22, 2022
• First Submitted That Met QC Criteria: February 22, 2022
• First Posted (Actual): March 3, 2022

Study Record Updates

• Last Update Posted (Actual): July 17, 2023
• Last Update Submitted That Met QC Criteria: July 13, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Keywords: intra abdominal candidiasis; candida; diagnostic method; metabolic profile; virulence
• Additional Relevant MeSH Terms: Digestive System Diseases; Pathologic Processes; Infections; Peritoneal Diseases; Disease Attributes; Bacterial Infections and Mycoses; Mycoses; Invasive Fungal Infections; Intraabdominal Infections; Candidiasis; Candidiasis, Invasive; Critical Illness; Peritonitis
• Other Study ID Numbers: 2021PI051

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No