Rapid identification of nonblood sterile site broth cultures using the FilmArray blood culture identification panel

First use of a new rapid multiplex PCR system for the microbiological diagnosis and the clinical management of severe infectious keratitis: A case report

Purpose

Observations

Conclusions and importance

Faster infection diagnostics for intensive care unit (ICU) patients

INTRODUCTION

: The patient admitted to intensive care units (ICU) is critically ill, to some extent immunosuppressed, with a high risk of infection, sometimes by multidrug-resistant microorganisms. In this context, the intensivist expects from the microbiology service quick and understandable information so that appropriate antimicrobial treatment for that particular patient and infection can be initiated.

AREAS COVERED

: In this review of recent literature (2015-2021), we identified diagnostic methods for the most prevalent infections in these patients through a search of the databases Pubmed, evidence-based medicine online, York University reviewers group, Cochrane, MBE-Trip, and Sumsearch using the terms: adult, clinical laboratory techniques, critical care, early diagnosis, microbiology, molecular diagnostic techniques, spectrometry and metagenomics.

EXPERT OPINION

: There has been an exponential surge in diagnostic systems used directly on blood and other samples to expedite microbial identification and antimicrobial susceptibility testing of pathogens. Few studies have thus far assessed their clinical impact; final outcomes will also depend on preanalytical and post-analytical factors. Besides, many of the resistance mechanisms cannot yet be detected with molecular techniques, which impairs the prediction of the actual resistance phenotype.

Nonetheless, this is an exciting field with much yet to explore.

Clinical Impact of the Expanded BioFire Blood Culture Identification 2 Panel in a U.S. Children's Hospital

The BioFire blood culture identification (BCID) panel decreases time to pathogen identification and time to optimal antimicrobial therapy. The BioFire blood culture identification 2 (BCID2) panel is an expanded panel with 17 additional targets and resistance genes; however, there are limited data on its impact in pediatric patients. We compared the BioFire BCID2 panel and the BCID panel by assaying BCID2 simultaneously with the current standard of care on 191 consecutive blood culture specimens at Children's Hospital Colorado. The primary outcome was equivalence, measured as percent agreement between the two panels and standard culture. The theoretical reduction in time to optimal therapy was calculated overall, with subanalyses performed on Enterococcus species and Gram-negative resistance genes. The percent agreement was equivalent between the two panels, with BCID at 98% (95% confidence interval [CI], 95 to 100%) and BCID2 at 97% (95% CI, 93 to 99%); the difference was 1.2% (95% CI, -0.8, 3.1%; P < 0.0001). There was not a significant reduction in time to theoretical optimal therapy with BCID2 compared to BCID for all cultures (reduction of 9 h, P = 0.3). Notably, 13 Enterococcus faecalis isolates were detected on BCID2, which would have resulted in a theoretical reduction in time to optimal antimicrobial therapy of 34 h (P = 0.0046). Five CTX-M genes were detected for enteric bacteria. The BioFire BCID2 panel had equal rates of detection compared to the BioFire BCID panel in pediatric patients. It had the advantage of detecting more organisms at the species level, and significantly reducing time to theoretical optimal antimicrobial therapy for Enterococcus faecalis. With the additional resistance genes, it also has the potential to impact care with earlier identification of resistant enteric pathogens. IMPORTANCE The BioFire BCID2 panel is an accurate panel that is equivalent to the BioFire BCID panel compared to standard culture. The BioFire BCID2 panel offers several advantages over the BioFire BCID panel, including enterococcal species identification, Gram-negative resistance gene detection, Salmonella identification, and the added mecA/mecC and SCCmec right extremity junction (MREJ) target for better Staphylococcus aureus and coagulase-negative Staphylococcus (CoNS) differentiation. Most importantly, it provides additional clinical impact with the potential to decrease the time to optimal antimicrobial therapy compared to the BioFire BCID panel, with likely further impact at institutions with a higher prevalence of Gram-negative resistance.

Effective and Rapid Microbial Identification in Pediatric Osteoarticular Infections Using Blood Culture Bottles

BACKGROUND

The detection and identification of pathogenic microorganisms are essential for the treatment of osteoarticular infection. However, obtaining a sufficient amount of specimen from pediatric patients is often difficult. Herein, we aimed to demonstrate the effectiveness of the blood culture bottle (BCB) system in pediatric osteoarticular infections. We hypothesized that our BCB culture method is superior to the conventional swab and tissue culture methods in terms of required specimen size, incubation time, and microbial identification rate.

METHODS

We analyzed the prospectively collected data of pediatric patients who underwent surgical treatment for osteoarticular infections between August 2016 and October 2019. Four needles were dipped in the infected fluid or tissue during the surgical procedure as soon as the infected area was exposed and were used to inoculate 2 aerobic pediatric BCBs and 2 anaerobic general BCBs. We also collected 2 conventional swab samples and 2 tissue samples from the identical area. The microbial identification rate and the time required for identification were compared between BCB, swab, and tissue cultures.

RESULTS

Forty patients constituted the study group; 13 patients had osteomyelitis, 17 patients had septic arthritis, and 10 patients had both. Of these 40 patients, the microbial identification rate was higher with BCB cultures (27 [68%]) than with swab cultures (18 [45%]; p = 0.004) or tissue cultures (15 [38%]; p < 0.001). Nine samples (9 patients [23%]) were only positive in the BCB culture. Positive microbial growth was not detected with conventional culture methods when microorganisms did not grow on the BCB culture. Compared with swab culture (4.3 ± 1.1 days; p < 0.001) or tissue culture (4.4 ± 1.1 days; p < 0.001), the BCB culture reduced the time required for microbial identification (3.5 ± 0.9 days).

CONCLUSIONS

In pediatric osteoarticular infections, the BCB culture system improved the microbial identification rate, reduced the time to identification, and permitted a smaller-volume specimen, compared with traditional culture systems.

LEVEL OF EVIDENCE

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.