Combination of serum and peritoneal 1.3-beta-D-glucan can rule out intra-abdominal candidiasis in surgical critically ill patients: a multicenter prospective study.

BACKGROUND: Intra-abdominal candidiasis (IAC) is difficult to predict in critically ill patients with intra-abdominal infection, leading to the overuse of antifungal treatments. Serum and peritoneal 1.3-beta-D-glucan (sBDG and pBDG) have been proposed to confirm or invalidate the diagnosis of IAC, but clinical studies have reported inconsistent results, notably because of heterogeneous populations with a low IAC prevalence. This study aimed to identify a high-risk IAC population and evaluate pBDG and sBDG in diagnosing IAC. METHODS: This prospective multicenter noninterventional French study included consecutive critically ill patients undergoing abdominal surgery for abdominal sepsis. The primary objective was to establish the IAC prevalence. The secondary objective was to explore whether sBDG and pBDG could be used to diagnose IAC. Wako® beta-glucan test (WT, Fujifilm Wako Chemicals Europe, Neuss, Germany) was used for pBDG measurements. WT and Fungitell® beta-D-glucan assay (FA, Associate of Cape Cod, East Falmouth, USA) were used for sBDG measurements. RESULTS: Between 1 January 2020 and 31 December 2022, 199 patients were included. Patients were predominantly male (63%), with a median age of 66 [54-72] years. The IAC prevalence was 44% (87/199). The main IAC type was secondary peritonitis. Septic shock occurred in 63% of cases. After multivariate analysis, a nosocomial origin was associated with more IAC cases (P = 0.0399). The median pBDG level was significantly elevated in IAC (448 [107.5-1578.0] pg/ml) compared to non-IAC patients (133 [16.0-831.0] pg/ml), P = 0.0021. For a pBDG threshold of 45 pg/ml, the negative predictive value in assessing IAC was 82.3%. The median sBDG level with WT (n = 42) at day 1 was higher in IAC (5 [3.0-9.0] pg/ml) than in non-IAC patients (3 [3.0-3.0] pg/ml), P = 0.012. Similarly, median sBDG level with FA (n = 140) at day 1 was higher in IAC (104 [38.0-211.0] pg/ml) than in non-IAC patients (50 [23.0-141.0] pg/ml), P = 0.009. Combining a peritonitis score < 3, sBDG < 3.3 pg/ml (WT) and pBDG < 45 pg/ml (WT) yielded a negative predictive value of 100%. CONCLUSION: In critically ill patients with intra-abdominal infection requiring surgery, the IAC prevalence was 44%. Combining low sBDG and pBDG with a low peritonitis score effectively excluded IAC and could limit unnecessary antifungal agent exposure. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov (ID number 03997929, first registered on June 24, 2019).

Reappraisal of intra-abdominal candidiasis: insights from peritoneal fluid analysis.

BACKGROUND: The understanding of high mortality associated with intra-abdominal candidiasis (IAC) remains limited. While Candida is considered a harmless colonizer in the digestive tract, its role as a true pathogen in IAC is still debated. Evidence regarding Candida virulence in the human peritoneal fluid are lacking. We hypothesized that during IAC, Candida albicans develops virulence factors to survive to new environmental conditions. The objective of this observational exploratory monocentric study is to investigate the influence of peritoneal fluid (PF) on the expression of C. albicans virulence using a multimodal approach. MATERIALS AND METHODS: A standardized inoculum of a C. albicans (3.106 UFC/mL) reference strain (SC5314) was introduced in vitro into various PF samples obtained from critically ill patients with intra-abdominal infection. Ascitic fluids (AFs) and Sabouraud medium (SBD) were used as control groups. Optical microscopy and conventional culture techniques were employed to assess the morphological changes and growth of C. albicans. Reverse transcriptase qPCR was utilized to quantify the expression levels of five virulence genes. The metabolic production of C. albicans was measured using the calScreener™ technology. RESULTS: A total of 26 PF samples from patients with secondary peritonitis were included in the study. Critically ill patients were mostly male (73%) with a median age of 58 years admitted for urgent surgery (78%). Peritonitis was mostly hospital-acquired (81%), including 13 post-operative peritonitis (50%). The infected PF samples predominantly exhibited polymicrobial composition. The findings revealed substantial variability in C. albicans growth and morphological changes in the PF compared to ascitic fluid. Virulence gene expression and metabolic production were dependent on the specific PF sample and the presence of bacterial coinfection. CONCLUSIONS: This study provides evidence of C. albicans virulence expression in the peritoneal fluid. The observed variability in virulence expression suggests that it is influenced by the composition of PF and the presence of bacterial coinfection. These findings contribute to a better understanding of the complex dynamics of intra-abdominal candidiasis and advocate for personalized approach for IAC patients. Trial registration https://clinicaltrials.gov/ (NCT05264571; February 22, 2022).

Protozoans in subgingival biofilm: clinical and bacterial associated factors and impact of scaling and root planing treatment.

Objective: In patients with periodontitis, identification of protozoans and evaluation of some bacteria and clinical parameters associated and assessment of scaling and root planing (SRP) impact on their detection. Methods: Before and after SRP, subgingival microbiota was collected in two pathological and one healthy site from 30 periodontitis patients. One healthy site from 30 control patients was also sampled. The usual clinical periodontal parameters were recorded; microbial detection was determined by PCR hybridization system for bacteria and qPCR for protozoans. Results: In periodontitis group, Trichomonas tenax and two subtypes of Entamoeba gingivalis (ST1 and a variant ST2) were detected in respectively 33.3%, 70% and 18.3% of pathological samples, and in 6.7%, 10% and 3.3% healthy samples. In control group, ST1 alone was found in 3.3% of individuals. ST1 was associated with Gingival Index, Clinical Attachment Level (p ≤ 0.03) and with the total bacterial count (p = 0.02). T. tenax alone was associated with P. gingivalis, T. denticola and E. nodatum (p ≤ 0,02). After therapy, only T. tenax detection decreased significantly (p = 0.004) and no association between the protozoan elimination and improvement of pathological sites was found. Conclusions: Protozoans were associated with some clinical parameters and/or periodontopathogens in patients with periodontitis.

Determination of 1,3-ß-D-glucan in the peritoneal fluid for the diagnosis of intra-abdominal candidiasis in critically ill patients: a pilot study.

BACKGROUND: Decision to start an anti-fungal therapy in intra-abdominal candidiasis (IAC) is complex. Yeast culture, considered the gold standard, suffers from a delayed response time and exposes the patient to delayed introduction of anti-fungal therapy. We sought to evaluate the performance and feasibility of measuring 1,3-ß-D-glucan (1,3-BDG) in the peritoneal fluid (PF) for the diagnosis of IAC. METHODS: We analyzed retrospectively all PF obtained during abdominal surgery for critically ill adult patients presenting intra-abdominal infections. For each PF sample, direct examination, bacterial and fungal culture, fungal PCR and 1,3-BDG measurements were performed. The diagnostic performance of each technique and the Peritonitis score were calculated considering the positive yeast culture as the reference. The levels of 1,3-BDG were compared between IAC and non-IAC patients. RESULTS: During an 8-month period in 2016, 33 PF samples were recovered. Median (interquartile range) SAPS 2 and SOFA scores were 44 (9-94) and 9 (4-15), respectively. There were seven cases of IAC, 14 of bacterial peritonitis and 12 of undocumented peritonitis. All IAC cases were secondary peritonitis, with a 1,3-BDG level of 1461 (325-5000) versus 224 (68-1357) pg/mL in the non-IAC group (P=0.03). When the 1,3-BDG level was ≤310 pg/mL, its negative predictive value was 100%. CONCLUSIONS: In secondary peritonitis, a peritoneal measurement of 1,3-BDG ≤310 pg/mL could rule out IAC.