Practical Comparison of the BioFire FilmArray Pneumonia Panel to Routine Diagnostic Methods and Potential Impact on Antimicrobial Stewardship in Adult Hospitalized Patients with Lower Respiratory Tract Infections

Diagnostic Accuracy of Blind Bronchial Sample Testing by BioFire Pneumonia plus Panel in Pediatric Intensive Care Unit Patients and Its Impact in Early Adaptation of Antimicrobial Therapy: A Prospective Observational Study

BACKGROUND

Community-acquired and nosocomial lower-respiratory-tract infections in critically ill pediatric patients require early appropriate antibiotic therapy to optimize outcomes. Using blind bronchial samples, we assessed the diagnostic performance of the rapid-multiplex polymerase chain reaction (PCR) assay BioFire Pneumonia plus Panel vs. reference standard culturing with antimicrobial susceptibility testing.

METHODS

For this prospective observational study in a single pediatric intensive care unit, we included consecutive patients younger than 18 years admitted for suspected community-, hospital- or ventilator-associated pneumonia in 2021-2022. Sensitivity, specificity, positive predictive value and negative predictive value of the multiplex PCR assay were determined. The kappa coefficient was computed to assess agreement, and univariate analyses were done to identify factors associated with discrepancies between the 2 diagnostic methods.

RESULTS

Of the 36 included patients (median age, 1.4 years; interquartile range, 0.2-9.2), 41.7%, 27.8%, and 30.5% had community-, hospital- and ventilator-associated pneumonia, respectively. The overall κ was 0.74, indicating good agreement. Overall, the sensitivity of the multiplex PCR assay was 92% (95% CI: 77%-98%) and specificity 95% (95% CI: 92%-97%), with variations across microorganisms. The median time from sample collection to antimicrobial susceptibility test results was 3.9 (2.5-15) hours with the multiplex PCR assay and 60.5 (47.6-72.2) hours with the reference technique.

CONCLUSION

The BioFire Pneumonia plus Panel used to test blind bronchial samples had satisfactory diagnostic performance in critically ill pediatric patients. The rapid results provided by this test may improve the appropriateness of antimicrobial therapy and help minimize the use of antibiotics.

Utility of a multiplex pathogen detection system directly from respiratory specimens for treatment and diagnostic stewardship

The availability of syndrome-based panels for various ailments has widened the scope of diagnostics in many clinical settings. These panels can detect a multitude of pathogens responsible for a particular condition, which can lead to a timely diagnosis and better treatment outcomes. In contrast to traditional identification methods based on pathogen growth on culture, syndrome-based panels offer a quicker diagnosis, which can be especially beneficial in situations requiring urgent care, such as intensive care units. One such panel is the Biofire Filmarray Pneumonia plus Panel (BFP), which we have compared against microbiological culture and identification. The lower respiratory samples from patients were tested with BFP, culture, and identification with culture considered the gold standard. The phenotypic antibiotic susceptibility results (Vitek 2) were compared with the antimicrobial resistance (AMR) genes detected in BFP. Statistical analysis was carried out using GraphPad 7.0 and MS Excel (Microsoft Inc.). The results showed a positive percent agreement of 100% and a negative percent agreement of 47.8% with an overall agreement of 76.72% compared to culture. BFP was better at identifying fastidious bacteria, and the agreement with culture was higher for high bacterial identification numbers (107 and 106). There was also a correlation between the number of pathogens detected and growth in culture. Carbapenemase genes were detected in around 80% of phenotypically resistant samples and correlated with in-house PCR 60% of the time. Hence, BFP results need to be interpreted with caution especially when multiple pathogens are detected. Similarly, the presence or absence of AMR genes should be used to guide the therapy while being watchful of unusual resistance or susceptibility. The cost constraints and low throughput call for patient selection criteria and prioritization in emergency or resource-limited conditions.IMPORTANCEApplication of syndrome-based panels in clinical microbiology is of huge support in infectious conditions requiring urgent interventions, such as pneumonia. Interpreting the results requires caution; hence, we have compared the results obtained from Biofire Filmarray Pneumonia plus Panel with standard microbiological methods.

Multiplex PCR for respiratory bacteria in acute care

The purpose of the study was to evaluate the clinical utility of multiplex PCR for detecting bacterial respiratory pathogens in nasopharyngeal samples. Acutely ill adults in the emergency department with respiratory infection symptoms, fever, chest pain or poor general condition were enrolled for this cohort study. Samples were stored at -70 °C until being analysed with multiplex PCR for seven respiratory bacteria. Of the 912 patients enrolled, those with positive bacterial samples (n = 130, 14%) were significantly younger than those with a negative finding (55.5 years vs 62.2 years, p < 0.001), and their mean C-reactive protein (CRP) concentration was higher (110 mg/L vs 59 mg/L, p < 0.0001). Patients with a positive respiratory bacterial finding had a higher probability of pneumonia (35% vs 13%, p < 0.001) and a higher likelihood of receiving a prescription for antibiotics than those with a negative finding (79% vs 59%, p < 0.0001). Positive detection of Streptococcus pneumoniae was associated with a 4.5-fold risk of pneumonia in a multivariate model and detection of an atypical respiratory pathogen with a 9-fold risk. Bacterial PCR performed on nasopharyngeal samples appeared to offer a valuable addition to the diagnostics of infections in adults in acute care.

Comparative performance of biofire pneumonia panel and standard culture-based methods for diagnosing pneumonia in critically ill patients: Impact on antibiotic stewardship

INTRODUCTION

Lower respiratory tract infections (LRTIs) are a common cause of morbidity and mortality worldwide. Accurate identification of the pathogens causing LRTIs is crucial for ensuring of diagnostic and antibiotic stewardship. The Biofire Pneumonia Panel (BFPP) is a molecular diagnostic test that allows rapid detection of various bacterial and viral pathogens. In this study, we compared the performance of BFPP with standard culture methods for the detection of pathogens.

MATERIALS AND METHODS

Respiratory samples from 70 patient with suspected LRTIs were tested using both BFPP and standard culture methods. The distribution of isolated bacterial pathogens was analyzed, and the sensitivity and specificity of BFPP were calculated. Additionally, the performance of BFPP in detecting antimicrobial resistance genes was evaluated. The results were compared with those obtained from VITEK-2 antimicrobial susceptibility testing and culture-based methods.

RESULTS

Among the suspected LRTI cases, BFPP identified a single pathogen in 32.8% of cases and multiple pathogens in 40% of cases. The standard culture method detected a single pathogen in 47.1% of cases. BFPP showed a sensitivity of 93.9% and a specificity of 45.9% for the total sample. The performance of BFPP in detecting antimicrobial resistance genes varied for different pathogens with overall sensitivity of 40.1% and specificity of 95.9%.

CONCLUSION

The Biofire Pneumonia Panel (BFPP) demonstrated high sensitivity for several bacterial pathogens, indicating its potential as a rapid diagnostic tool. However, its performance varied for different microorganisms, and it had limitations in detecting certain pathogens and antimicrobial resistance genes for which still required more further studies to explore different resistance gene mechanism that can be incorporated in this panel in future. The BFPP can complement standard culture methods as a rapid tool in the diagnosis of LRTIs.

Optimizing Antimicrobial Stewardship in the Emergency Department

Antibiotic stewardship is a core component of emergency department (ED) practice and impacts patient safety, clinical outcomes, and public health. The unique characteristics of ED practice, including crowding, time pressure, and diagnostic uncertainty, need to be considered when implementing antibiotic stewardship interventions in this setting. Rapid advances in pathogen detection and host response biomarkers promise to revolutionize the diagnosis of infectious diseases in the ED, but such tests are not yet considered standard of care. Presently, clinical decision support embedded in the electronic health record and pharmacist-led interventions are the most effective ways to improve antibiotic prescribing in the ED.

Breaking Boundaries in Pneumonia Diagnostics: Transitioning from Tradition to Molecular Frontiers with Multiplex PCR

The advent of rapid molecular microbiology testing has revolutionized infectious disease diagnostics and is now impacting pneumonia diagnosis and management. Molecular platforms offer highly multiplexed assays for diverse viral and bacterial detection, alongside antimicrobial resistance markers, providing the potential to significantly shape patient care. Despite the superiority in sensitivity and speed, debates continue regarding the clinical role of multiplex molecular testing, notably in comparison to standard methods and distinguishing colonization from infection. Recent guidelines endorse molecular pneumonia panels for enhanced sensitivity and rapidity, but implementation requires addressing methodological differences and ensuring clinical relevance. Diagnostic stewardship should be leveraged to optimize pneumonia testing, emphasizing pre- and post-analytical strategies. Collaboration between clinical microbiologists and bedside providers is essential in developing implementation strategies to maximize the clinical utility of multiplex molecular diagnostics in pneumonia. This narrative review explores these multifaceted issues, examining the current evidence on the clinical performance of multiplex molecular assays in pneumonia, and reflects on lessons learned from previous microbiological advances. Additionally, given the complexity of pneumonia and the sensitivity of molecular diagnostics, diagnostic stewardship is discussed within the context of current literature, including implementation strategies that consider pre-analytical and post-analytical modifications to optimize the clinical utility of advanced technologies like multiplex PCR.

Evaluation and clinical practice of pathogens and antimicrobial resistance genes of BioFire FilmArray Pneumonia panel in lower respiratory tract infections

BACKGROUND

Existing panels for lower respiratory tract infections (LRTIs) are slow and lack quantification of important pathogens and antimicrobial resistance, which are not solely responsible for their complex etiology and antibiotic resistance. BioFire FilmArray Pneumonia (PN) panels may provide rapid information on their etiology.

METHODS

The bronchoalveolar lavage fluid of 187 patients with LRTIs was simultaneously analyzed using a PN panel and cultivation, and the impact of the PN panel on clinical practice was assessed. The primary endpoint was to compare the consistency between the PN panel and conventional microbiology in terms of etiology and drug resistance, as well as to explore the clinical significance of the PN panel. The secondary endpoint was pathogen detection using the PN panel in patients with community-acquired pneumonia (CAP) or hospital-acquired pneumonia (HAP).

RESULTS

Fifty-seven patients with HAP and 130 with CAP were included. The most common pathogens of HAP were Acinetobacter baumannii and Klebsiella pneumoniae, with the most prevalent antimicrobial resistance (AMR) genes being CTX-M and KPC. For CAP, the most common pathogens were Haemophilus influenzae and Staphylococcus aureus, with the most frequent AMR genes being CTX-M and VIM. Compared with routine bacterial culture, the PN panel demonstrated an 85% combined positive percent agreement (PPA) and 92% negative percent agreement (NPA) for the qualitative identification of 13 bacterial targets. PN detection of bacteria with higher levels of semi-quantitative bacteria was associated with more positive bacterial cultures. Positive concordance between phenotypic resistance and the presence of corresponding AMR determinants was 85%, with 90% positive agreement between CTX-M-type extended-spectrum beta-lactamase gene type and phenotype and 100% agreement for mecA/C and MREJ. The clinical benefit of the PN panel increased by 25.97% compared with traditional cultural tests.

CONCLUSION

The bacterial pathogens and AMR identified by the PN panel were in good agreement with conventional cultivation, and the clinical benefit of the PN panel increased by 25.97% compared with traditional detection. Therefore, the PN panel is recommended for patients with CAP or HAP who require prompt pathogen diagnosis and resistance identification.

New Guidelines for Severe Community-acquired Pneumonia

In 2023, the new European guidelines on severe community-acquired pneumonia, providing clinical practice recommendations for the management of this life-threatening infection, characterized by a high burden of mortality, morbidity, and costs for the society. This review article aims to summarize the principal evidence related to eight different questions covered in the guidelines, by also highlighting the future perspectives for research activity.

Risk of Multidrug-Resistant Pathogens in Severe Community-Acquired Pneumonia

Severe community-acquired pneumonia (SCAP) is difficult to treat when caused by difficult-to-treat (DTR) pathogens because of limited treatment options and poorer clinical outcomes. Over time, several predictive scoring systems based on risk factors for infection with multidrug resistant pathogens have been developed. We reviewed the available tools for identifying DTR pathogens as the cause of SCAP, both predictive scoring systems and rapid diagnostic methods, to develop management strategies aimed at early identification of DTR pathogens, reducing broad-spectrum antibiotic use and improving clinical outcomes. The scoring systems reviewed show considerable heterogeneity among them at the level of the region studied, the definition of risk factors, as well as which DTR pathogens are the target pathogens. The models described have shown limited effectiveness in reducing inappropriate antibiotic treatment or improving patient outcomes by themselves. However, predictive models could serve as a first step in identifying DTR pathogen infections as part of a larger detection algorithm. Rapid diagnostic tools, such as multiplex polymerase chain reaction, would be useful for the rapid identification of pneumonia-causing pathogens and their resistance mechanisms. In resource-limited settings, rapid tests should be limited to patients at high risk of developing SCAP due to DTR pathogens. We propose an integrative algorithm based on the different scores, taking into account local epidemiological data, where ideally each center should have an antimicrobial stewardship program.

Clinical evaluation of the BioFire Respiratory Pathogen Panel for the guidance of empirical antimicrobial therapy in critically ill patients with hospital-acquired pneumonia: A multicenter, quality improvement project

BACKGROUND

We aimed to determine whether implementing antimicrobial stewardship based on multiplex bacterial PCR examination of respiratory fluid can enhance outcomes of critically ill patients with hospital-acquired pneumonia (HAP).

METHODS

We conducted a quality improvement study in two hospitals in France. Adult patients requiring invasive mechanical ventilation with a diagnosis of HAP were included. In the pre-intervention period (August 2019 to April 2020), antimicrobial therapy followed European guidelines. In the «intervention» phase (June 2020 to October 2021), treatment followed a multiplex PCR-guided protocol. The primary endpoint was a composite endpoint made of mortality on day 28, clinical cure between days 7 and 10, and duration of invasive mechanical ventilation on day 28. The primary outcome was analyzed with a DOOR strategy.

RESULTS

A total of 443 patients were included in 3 ICUs from 2 hospitals (220 pre-intervention; 223 intervention). No difference in the ranking of the primary composite outcome was found (DOOR: 50.3%; 95%CI, 49.9%-50.8%). The number of invasive mechanical ventilation-free days at day 28 was 10.0 [0.0; 19.0] in the baseline period and 9.0 [0.0; 20.0] days during the intervention period (p = 0.95). The time-to-efficient antimicrobial treatment was 0.43 ± 1.29 days before versus 0.55 ± 1.13 days after the intervention (p = 0.56).

CONCLUSION

Implementation of Rapid Multiplex PCR to guide empirical antimicrobial therapy for critically ill patients with HAP was not associated with better outcomes. However, adherence to stewardship was low, and the study may have had limited power to detect a clinically important difference.

Practice Versus Potential: The Impact of the BioFire FilmArray Pneumonia Panel on Antibiotic Use in Children

BACKGROUND

The BioFire FilmArray Pneumonia Panel (BFPP), a multiplex PCR panel for the diagnosis of lower respiratory tract infections, has been proposed as a tool for antimicrobial stewardship. Few studies evaluate real-world implementation of the BFPP and no studies focus exclusively on children. Our institution implemented BFPP testing without restrictions.

METHODS

We conducted a retrospective cohort study in children hospitalized at St. Louis Children's Hospital to (1) characterize the use of the BFPP in pediatric patients and (2) assess how results impacted antibiotic use. We included all BFPP tests obtained during the first year after the introduction of the test, September 2021 through August 2022. The primary outcome was change in antibiotic therapy within 24 hours of results, which was compared to the potential change in antibiotic therapy determined by two infectious diseases clinicians.

RESULTS

One hundred sixty-nine tests from 126 patients were included. Nine patients were immunocompromised and 19 had chronic tracheostomy. The majority of tests were sent from tracheal aspirate specimens (92%) and from patients in an intensive care unit (94%). Only 51% of tests were obtained due to respiratory failure or suspected pneumonia. For 80% of test results, there was potential to change antibiotics, but change occurred in only 46% of tests in practice. Antibiotic escalation was more common (26%) than de-escalation (15%) or discontinuation (4.1%).

CONCLUSIONS

In a cohort of pediatric patients tested with the BFPP, the majority of tests were sent from tracheal aspirates and less than half of tests were associated with a change in antibiotics.

Application of a multiplex molecular pneumonia panel and real-world impact on antimicrobial stewardship among patients with hospital-acquired and ventilator-associated pneumonia in intensive care units

BACKGROUND

The optimal timing for applying the BioFire FilmArray Pneumonia Panel (FAPP) in intensive care unit (ICU) patients with hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP) remains undefined, and there are limited data on its impact on antimicrobial stewardship.

METHODS

This retrospective study was conducted at a referral hospital in Taiwan from November 2019 to October 2022. Adult ICU patients with HAP/VAP who underwent FAPP testing were enrolled. Patient data, FAPP results, conventional microbiological testing results, and the real-world impact of FAPP results on antimicrobial therapy adjustments were assessed. Logistic regression was used to determine the predictive factors for bacterial detection by FAPP.

RESULTS

Among 592 respiratory specimens, including 564 (95.3%) endotracheal aspirate specimens, 19 (3.2%) expectorated sputum specimens and 9 (1.5%) bronchoalveolar lavage specimens, from 467 patients with HAP/VAP, FAPP testing yielded 368 (62.2%) positive results. Independent predictors for positive bacterial detection by FAPP included prolonged hospital stay (odds ratio [OR], 3.14), recent admissions (OR, 1.59), elevated C-reactive protein levels (OR, 1.85), Acute Physiology and Chronic Health Evaluation II scores (OR, 1.58), and septic shock (OR, 1.79). Approximately 50% of antimicrobial therapy for infections caused by Gram-negative bacteria and 58.4% for Gram-positive bacteria were adjusted or confirmed after obtaining FAPP results.

CONCLUSIONS

This study identified several factors predicting bacterial detection by FAPP in critically ill patients with HAP/VAP. More than 50% real-world clinical practices were adjusted or confirmed based on the FAPP results. Clinical algorithms for the use of FAPP and antimicrobial stewardship guidelines may further enhance its benefits.

Combination of a multiplex pneumonia panel and Gram staining for antimicrobial selection to treat lower respiratory tract infection

AIM

This study aimed to examine the utility of simultaneously performed the Film Array pneumonia panels (pneumonia panels) and Gram staining with the same specimens and evaluate their effect on antimicrobial selection.

METHODS

This prospective study, conducted from April 2022 to January 2023, enrolled adult patients with pneumonia, including those with ventilator-associated pneumonia (VAP). Specimens obtained at the time of sputum culture were tested using Gram staining and the pneumonia panel. The patients' characteristics and pneumonia panel results were assessed. We also evaluated the selection of antimicrobial agents for drug-resistant bacteria detected by the pneumonia panel.

RESULTS

This study comprised 39 patients: 25 patients (64.1%) underwent intubation, including 7 (17.9%) patients with VAP. Most tests were performed at the time of admission, while some were performed during hospitalization. Good quality sputum was obtained from intubated patients. The pneumonia panel detected drug-resistant bacteria in 12 cases. Six patients required antimicrobial escalation, while the antimicrobial regimen remained unchanged for 2 patients in whom Pseudomonas aeruginosa was detected and had already received meropenem. The attending physician did not change the antimicrobials, considering the results of Gram staining and the patient's general condition in 4 patients.

CONCLUSIONS

The pneumonia panel might be useful for detecting drug-resistant organisms at an early stage. It may be important to take the Gram staining results and the patient's condition into account with pneumonia panel for appropriate antibiotic prescription.

Novel and Rapid Diagnostics for Common Infections in the Critically Ill Patient

There are several novel platforms that enhance detection of pathogens that cause common infections in the intensive care unit. These platforms have a sample to answer time of a few hours, are often higher yield than culture, and have the potential to improve antibiotic stewardship.

Evaluation of the clinical relevance of the Biofire© FilmArray pneumonia panel among hospitalized patients

PURPOSE

Panel PCR tests provide rapid pathogen identification. However, their diagnostic performance is unclear. We assessed the performance of the Biofire© FilmArray pneumonia (PN)-panel against standard culture in broncho-alveolar lavage (BAL) samples.

METHODS

Setting: University Hospital Basel (February 2019 to July 2020), including hospitalized patients with a BAL (± pneumonia). We determined sensitivity and specificity of the PN-panel against standard culture. Using univariate logistic regression, we calculated odds ratios (OR) for pneumonia according to PN-panel and culture status, stratifying by chronic pulmonary disease. We calculated ORs for pneumonia for different pathogens to estimate the clinical relevance.

RESULTS

We included 840 adult patients, 60% were males, median age was 68 years, 35% had chronic pulmonary disease, 21% had pneumonia, and 36% had recent antibiotic use. In 1078 BAL samples, bacterial pathogens were detected in 36% and 16% with PN-panel and culture, respectively. The overall sensitivity and specificity of the PN-panel was high, whereas the positive predictive value was low. The OR of pneumonia was 1.1 (95% CI 0.7-1.6) for PN-panel-positive only; 2.6 (95% CI 1.3-5.3) for culture-positive only, and 1.6 (95% CI 1.0-2.4) for PN-panel and culture-positive. The detection rate of Haemophilus influenzae, Staphylococcus aureus, and Moraxella catarrhalis in the PN-panel was high but not associated with pneumonia.

CONCLUSION

While sensitivity and specificity of PN-panel are high compared to culture, pathogen detection did not correlate well with a pneumonia diagnosis. Patients with culture-positive BAL had the highest OR for pneumonia-thus the impact of the PN-panel on clinical management needs further evaluation in randomized controlled trials.

Impact of Multiplex PCR in the Therapeutic Management of Severe Bacterial Pneumonia

Pneumonia is a common and severe illness that requires prompt and effective management. Advanced, rapid, and accurate tools are needed to diagnose patients with severe bacterial pneumonia, and to rapidly select appropriate antimicrobial therapy, which must be initiated within the first few hours of care. Two multiplex molecular tests, Unyvero HPN and FilmArray Pneumonia+ Panel, have been developed using the multiplex polymerase chain reaction (mPCR) technique to rapidly identify pathogens and their main antibiotic resistance mechanisms from patient respiratory specimens. Performance evaluation of these tests showed strong correlations with reference techniques. However, good knowledge of their indications, targets, and limitations is essential. Collaboration with microbiologists is, therefore, crucial for their appropriate use. Under these conditions, and with standardized management, these rapid tests can improve the therapeutic management of severe pneumonia faster, more precisely, and with narrow-spectrum antibiotic therapy. Further randomized controlled trials are needed to address the many unanswered questions about multiplex rapid molecular testing during the diagnosis and the management of severe pneumonia. This narrative review will address the current knowledge, advantages, and disadvantages of these tests, and propose solutions for their routine use.

Effects of clinically achievable pulmonary antibiotic concentrations on the recovery of bacteria: in vitro comparison of the BioFire FILMARRAY Pneumonia Panel versus conventional culture methods in bronchoalveolar lavage fluid

Empiric antibiotics may affect bacterial pathogen recovery using conventional culture methods (CCMs), while PCR-based diagnostics are likely less affected. Herein, we conducted an in vitro study of bronchoalveolar lavage fluid (BAL) inoculated with bacteria and clinically relevant antibiotic concentrations to compare the recovery between the BioFire FILMARRAY Pneumonia Panel (Pn Panel) and CCMs. Remnant clinical BAL specimens were inoculated to ~105 cfu/mL using 12 clinical isolates. Isolates consisted of one wild-type (WT) and one or more resistant strains of: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. Piperacillin-tazobactam, cefepime, meropenem, levofloxacin, or vancomycin was added to achieve pulmonary epithelial lining fluid peak and trough concentrations. Post-exposure cfu/mL was quantified by CCMs and simultaneously tested by the PN Panel for identification and semi-quantitative genetic copies/mL. CCM results were categorized as significant growth (SG) (≥1 × 104), no significant growth (NSG) (≥1 × 103, <1 × 104), or no growth (NG) (<1 × 103). The PN Panel accurately identified all isolates, resistance genes, and reported ≥106 genetic copies/mL regardless of antibiotic exposure. The CCM also identified all S. aureus strains exposed to vancomycin. For WT Gram-negative isolates exposed to antibiotics, SG, NSG, and NG were observed in 7/52 (13%), 18/52 (35%), and 27/52 (52%) of CCM experiments, respectively. For resistant Gram-negatives isolates, SG, NSG, and NG were observed in 62/88 (70%), 17/88 (19%), and 9/88 (10%), respectively. These in vitro data demonstrate that the PN Panel is able to identify Gram-negative pathogens in the presence of clinically significant antibiotic concentrations when CCM may not.

Real-life Assessment of BioFire FilmArray Pneumonia Panel in Adults Hospitalized With Respiratory Illness

BACKGROUND

Inability to identify the microbial etiology of lower respiratory tract infection leads to unnecessary antibiotic use. We evaluated the utility of the BioFire FilmArray Pneumonia Panel (BioFire PN) to inform microbiologic diagnosis.

METHODS

Hospitalized adults with respiratory illness were recruited; sputa and clinical/laboratory data were collected. Sputa were cultured for bacteria and tested with BioFire PN. Microbial etiology was adjudicated by 4 physicians. Bacterial polymerase chain reaction (PCR) was compared with culture and clinical adjudication.

RESULTS

Of 298 sputa tested, BioFire PN detected significantly more pathogens (350 bacteria, 16 atypicals, and 164 viruses) than sputum culture plus any standard-of-care testing (91% vs 60%, P < .0001). When compared with culture, the sensitivity of BioFire PN for individual bacteria was 46% to 100%; specificity, 61% to 100%; and negative predictive value, 92% to 100%. Cases were adjudicated as viral (n = 58) and bacterial (n = 100). PCR detected bacteria in 55% of viral cases and 95% of bacterial (P < .0001). High serum procalcitonin and bacterial adjudication were more often associated with sputa with 106 or 107 copies detected.

CONCLUSIONS

Multiplex PCR testing of sputa for bacteria is useful to rule out bacterial infection with added value to detect viruses and atypical bacteria.

Optimized Antibiotic Management of Critically Ill Patients with Severe Pneumonia Following Multiplex Polymerase Chain Reaction Testing: A Prospective Clinical Exploratory Trial

Molecular diagnostic testing is assumed to enable fast respiratory pathogen identification and contribute to improved pneumonia management. We set up a prospective clinical trial at a tertiary hospital intensive care unit including adult patients suspected of severe pneumonia from whom a lower respiratory tract sample could be obtained. During control periods (CPs), routine testing was performed, and during intervention periods (IPs), this testing was completed with the FilmArray Pneumonia Panel plus test (FA-PNEU) executed 24/7. The main objective was to measure the impact of FA-PNEU results in terms of reduced time to targeted antimicrobial treatment administration. Over a 10-month period, analysis was performed on 35 CP and 50 IP patients. The median time to targeted antimicrobial treatment administration was reduced to 4.3 h in IPs compared to 26.4 h in CPs, with 54% of IP patients having FA-PNEU results that led to a treatment modification, of which all but one were targeted. Modifications included 10 (37%) de-escalations, 7 (25.9%) escalations, 3 (11.1%) regimen switches, and 7 (25.9%) complete antimicrobial discontinuations. FA-PNEU results were available with a 42.3 h gain compared to routine identification. This prospective study confirmed retrospective data demonstrating the benefit of FA-PNEU testing in severe pneumonia management of critically ill patients through improved antimicrobial use.

Effective Approaches to Diagnostic Stewardship of Syndromic Molecular Panels

BACKGROUND

Syndromic molecular panels for the diagnosis of gastroenteritis, meningitis/encephalitis, and pneumonia are becoming routinely used for patient care throughout the world.

CONTENT

These rapid, sample-to-answer assays have great potential to improve patient care, infection control, and antimicrobial stewardship. However, diagnostic stewardship is essential for their optimal use and accuracy, and interventions can be applied at all phases of the diagnostic process.

SUMMARY

The aim of this review article is to describe effective approaches to diagnostic stewardship for syndromic molecular panels to ensure appropriate test utilization and quality assured results.

A Systematic Literature Review to Identify Diagnostic Gaps in Managing Immunocompromised Patients With Cancer and Suspected Infection

Patients with cancer are increasingly vulnerable to infections, which may be more severe than in the general population. Improvements in rapid and timely diagnosis to optimize management are needed. We conducted a systematic literature review to determine the unmet need in diagnosing acute infections in immunocompromised patients with cancer and identified 50 eligible studies from 5188 records between 1 January 2012 and 23 June 2022. There was considerable heterogeneity in study designs and parameters, laboratory methods and definitions, and assessed outcomes, with limited evaluation of diagnostic impact on clinical outcomes. Culture remains the primary diagnostic strategy. Fewer studies employing molecular technologies exist, but emerging literature suggests that pathogen-agnostic molecular tests may add to the diagnostic armamentarium. Well-designed clinical studies using standardized methodologies are needed to better evaluate performance characteristics and clinical and economic impacts of emerging diagnostic techniques to improve patient outcomes.

Exploring the Utility of Multiplex Infectious Disease Panel Testing for Diagnosis of Infection in Different Body Sites: A Joint Report of the Association for Molecular Pathology, American Society for Microbiology, Infectious Diseases Society of America, and Pan American Society for Clinical Virology

The use of clinical molecular diagnostic methods for detecting microbial pathogens continues to expand and, in some cases, supplant conventional identification methods in various scenarios. Analytical and clinical benefits of multiplex molecular panels for the detection of respiratory pathogens have been demonstrated in various studies. The use of these panels in managing different patient populations has been incorporated into clinical guidance documents. The Association for Molecular Pathology's Infectious Diseases Multiplex Working Group conducted a review of the current benefits and challenges to using multiplex PCR for the detection of pathogens from gastrointestinal tract, central nervous system, lower respiratory tract, and joint specimens. The Working Group also discusses future directions and novel approaches to detection of pathogens in alternate specimen types, and outlines challenges associated with implementation of these multiplex PCR panels.

Performance evaluation of a PCR panel (FilmArray® Pneumonia Plus) for detection of respiratory bacterial pathogens in respiratory specimens: A systematic review and meta-analysis

BACKGROUND

Accuracy and timing of antibiotic therapy remain a challenge for lower respiratory tract infections. New molecular techniques using Multiplex Polymerase Chain Reaction, including the FilmArray® Pneumonia Plus Panel [FAPP], have been developed to address this. The aim of this study is to evaluate the FAPP diagnostic performance for the detection of the 15 typical bacteria of the panel from respiratory samples in a meta-analysis from a systematic review.

METHODS

We searched PubMed and EMBASE from January 1, 2010, to December 31, 2022, and selected any study on the FAPP diagnostic performance on respiratory samples compared to the reference standard, bacterial culture. The main outcome was the overall diagnostic accuracy with sensitivity and specificity. We calculated the log Diagnostic Odds Ratio and analyzed performance for separate bacteria, antimicrobial resistance genes, and according to the sample type. We also reported the FAPP turnaround time and the out-of-panel bacteria number and species. This study is registered with PROSPERO (CRD42021226280).

RESULTS

From 10 317 records, we identified 30 studies including 8 968 samples. Twenty-one were related to intensive care. The overall sensitivity and specificity were 94% [95% Confidence Interval (CI) 91-95] and 98% [95%CI 97-98], respectively. The log Diagnostic Odds Ratio was 6.35 [95%CI 6.05-6.65]. 9.3% [95%CI 9.2-9.5] of bacteria detected in culture were not included in the FAPP panel.

CONCLUSION

This systematic review reporting the FAPP evaluation revealed a high accuracy. This test may represent an adjunct tool for pulmonary bacterial infection diagnostic and antimicrobial stewardship. Further evidence is needed to assess the impact on clinical outcome.

Evaluation of the BioFire® FilmArray® Pneumonia plus Panel for Detecting Bacterial Etiological Agents of Lower Respiratory Tract Infections in an Oncologic Hospital. Comparison with Conventional Culture Method

Conventional methods used to determine pneumonia pathogens are characterized by low sensitivity and long turnaround times. Introducing new tests with better parameters in patients at higher risk of infections is highly anticipated. The results of the conventional quantitative culture method (CM) in determining the bacterial etiology of pneumonia were compared with the results of the Pneumonia plus Panel test (PNP; BioFire® Diagnostics, USA) in 79 samples of bronchoalveolar lavage (BAL). Materials were collected from 79 patients with suspected pneumonia treated in an oncologic hospital due to solid tumors. Only 16/79 BAL samples (20.3%) were true positive (TP) for bacterial etiology in CM vs. 27/79 samples (34.2%) true positive in the PNP test. The total agreement between methods of interpreting the result (positive or negative) was 84.8%. The most prevalent pathogens in both methods were Staphylococcus aureus, followed by Escherichia coli, Pseudomonas aeruginosa, and Haemophilus influenzae. The PNP test identified several respiratory pathogens that were not grown in culture. The semiquantitative value reported by the PNP test was higher than that reported by culture. The PNP test vs. combined test (PNP test and CM methods) demonstrated positive predictive value (PPV) and negative predictive value (NPV) values of 100.0% and 98.1%, and the sensitivity and specificity were 96.4% and 100.0%. The PNP test is a good tool for determining the etiology of bacterial pneumonia and may support the care of an oncologic patient. However, further large-sample studies are needed to research in strictly defined groups of oncologic patients.

Performance and Impact on Antibiotic Prescriptions of a Multiplex PCR in a Real-Life Cohort of Critically Ill Patients with Suspected Ventilated Pneumonia: A Retrospective Monocentric Observational Study

Pulmonary multiplex polymerase chain reaction (m-PCR) allows rapid pathogen detection. We aimed to assess its impact on initial antibiotic prescriptions in ventilated patients with suspected pneumonia. Between November 2020 and March 2022,ventilated patients with suspected pneumonia hospitalized in our ICU who benefited from respiratory sampling simultaneously tested using conventional microbiological methods and m-PCR were included. The proportion of appropriate changes in the initial antibiotic therapy following m-PCR results was assessed. We analyzed 104 clinical samples. Of the 47 negative m-PCR results, 16 (34%) led to an appropriate antibiotic strategy: 8 cessationsand 8 lack of initiation. Of the 57 positive m-PCR results, 51 (89%) resulted in an appropriate antibiotic strategy: 33 initiations, 2 optimizations, and 9 de-escalations. In the multivariate analysis, a positive m-PCR was associated with an appropriate antibiotic change (OR: 96.60; IC95% [9.72; 960.20], p < 0.001). A higher SAPS II score was negatively associated with an appropriate antibiotic change (OR: 0.96; IC95% [0.931; 0.997], p = 0.034). In our cohort, a positive m-PCR allowed for early initiation or adjustment of antibiotic therapy in almost 90% of cases. A negative m-PCR spared antibiotic use in onethird of cases. The impact of m-PCR results was reduced in the most severe patients.

Evaluation of point-of-care multiplex polymerase chain reaction in guiding antibiotic treatment of patients acutely admitted with suspected community-acquired pneumonia in Denmark: A multicentre randomised controlled trial

BACKGROUND

Rapid and accurate detection of pathogens is needed in community-acquired pneumonia (CAP) to enable appropriate antibiotics and to slow the development of antibiotic resistance. We aimed to compare the effect of point-of-care (POC) polymerase chain reaction (PCR) detection of respiratory pathogens added to standard care with standard care only (SCO) on antibiotic prescriptions after acute hospital admission.

METHODS AND FINDINGS

We performed a superiority, parallel-group, open-label, multicentre, randomised controlled trial (RCT) in 3 Danish medical emergency departments (EDs) from March 2021 to February 2022. Adults acutely admitted with suspected CAP during the daytime on weekdays were included and randomly assigned (1:1) to POC-PCR (The Biofire FilmArray Pneumonia Panel plus added to standard care) or SCO (routine culture and, if requested by the attending physician, target-specific PCR) analysis of respiratory samples. We randomly assigned 294 patients with successfully collected samples (tracheal secretion 78.4% or expectorated sputum 21.6%) to POC-PCR (n = 148, 50.4%) or SCO (146, 49.6%). Patients and investigators owning the data were blinded to the allocation and test results. Outcome adjudicators and clinical staff at the ED were not blinded to allocation and test results but were together with the statistician, blinded to data management and analysis. Laboratory staff performing standard care analyses was blinded to allocation. The study coordinator was not blinded. Intention-to-treat and per protocol analysis were performed using logistic regression with Huber-White clustered standard errors for the prescription of antibiotic treatment. Loss to follow-up comprises 3 patients in the POC-PCR (2%) and none in the SCO group. Intention-to-treat analysis showed no difference in the primary outcome of prescriptions of no or narrow-spectrum antibiotics at 4 h after admission for the POC-PCR (n = 91, 62.8%) odds ratio (OR) 1.13; (95% confidence interval (CI) [0.96, 1.34] p = 0.134) and SCO (n = 87, 59.6%). Secondary outcomes showed that prescriptions were significantly more targeted at 4-h OR 5.68; (95% CI [2.49, 12.94] p < 0.001) and 48-h OR 4.20; (95% CI [1.87, 9.40] p < 0.001) and more adequate at 48-h OR 2.11; (95% CI [1.23, 3.61] p = 0.006) and on day 5 in the POC-PCR group OR 1.40; (95% CI [1.18, 1.66] p < 0.001). There was no difference between the groups in relation to intensive care unit (ICU) admissions OR 0.54; (95% CI [0.10, 2.91] p = 0.475), readmission within 30 days OR 0.90; (95% CI [0.43, 1.86] p = 0.787), length of stay (LOS) IRR 0.82; (95% CI [0.63, 1.07] p = 0.164), 30 days mortality OR 1.24; (95% CI [0.32, 4.82] p = 0.749), and in-hospital mortality OR 0.98; (95% CI [0.19, 5.06] p = 0.986).

CONCLUSIONS

In a setting with an already restrictive use of antibiotics, adding POC-PCR to the diagnostic setup did not increase the number of patients treated with narrow-spectrum or without antibiotics. POC-PCR may result in a more targeted and adequate use of antibiotics. A significant study limitation was the concurrent Coronavirus Disease 2019 (COVID-19) pandemic resulting in an unusually low transmission of respiratory virus.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT04651712).

Ten Issues for Updating in Community-Acquired Pneumonia: An Expert Review

Community-acquired pneumonia represents the third-highest cause of mortality in industrialized countries and the first due to infection. Although guidelines for the approach to this infection model are widely implemented in international health schemes, information continually emerges that generates controversy or requires updating its management. This paper reviews the most important issues in the approach to this process, such as an aetiologic update using new molecular platforms or imaging techniques, including the diagnostic stewardship in different clinical settings. It also reviews both the Intensive Care Unit admission criteria and those of clinical stability to discharge. An update in antibiotic, in oxygen, or steroidal therapy is presented. It also analyzes the management out-of-hospital in CAP requiring hospitalization, the main factors for readmission, and an approach to therapeutic failure or rescue. Finally, the main strategies for prevention and vaccination in both immunocompetent and immunocompromised hosts are reviewed.

Antimicrobial Multidrug Resistance: Clinical Implications for Infection Management in Critically Ill Patients

The increasing incidence of antimicrobial resistance (AMR) worldwide represents a serious threat in the management of sepsis. Due to resistance to the most common antimicrobials prescribed, multidrug-resistant (MDR) pathogens have been associated with delays in adequate antimicrobial therapy leading to significant increases in mortality, along with prolonged hospital length of stay (LOS) and increases in healthcare costs. In response to MDR infections and the delay of microbiological results, broad-spectrum antibiotics are frequently used in empirical antimicrobial therapy. This can contribute to the overuse and misuse of antibiotics, further promoting the development of resistance. Multiple measures have been suggested to combat AMR. This review will focus on describing the epidemiology and trends concerning MDR pathogens. Additionally, it will explore the crucial aspects of identifying patients susceptible to MDR infections and optimizing antimicrobial drug dosing, which are both pivotal considerations in the fight against AMR. Expert commentary: The increasing AMR in ICUs worldwide makes the empirical antibiotic therapy challenging in septic patients. An AMR surveillance program together with improvements in MDR identification based on patient risk stratification and molecular rapid diagnostic tools may further help tailoring antimicrobial therapies and avoid unnecessary broad-spectrum antibiotics. Continuous infusions of antibiotics, therapeutic drug monitoring (TDM)-based dosing regimens and combination therapy may contribute to optimizing antimicrobial therapy and limiting the emergence of resistance.

The diagnostic utility of microscopic quality assessment of sputum samples in the era of rapid syndromic PCR testing

This prospective study assessed the value of initial microscopy evaluation of sputum samples submitted for rapid syndromic PCR-based testing. Bacterial detections by the BioFire FilmArray Pneumonia Panel plus in 126 high- and 108 low-quality sputum samples, based on initial microscopy evaluation in samples from patients with lower respiratory tract infections were compared. We found that high-quality samples had a higher proportion of bacterial detections compared to low-quality samples (P = 0.013). This included a higher proportion of detections of bacteria deemed clinically relevant by predefined criteria (70% and 55%, P = 0.016), as well as a higher proportion of detections of Haemophilus influenzae (36% and 20%, P = 0.010). High-quality samples also had more detections of bacteria with high semi-quantitative values. The study found no significant difference between high- and low-quality samples in the proportions of samples with a single species of bacteria detected, samples with a bacteria treated by the clinician, samples with detection of a proven etiology of community-acquired pneumonia by predefined criteria, the number of bacterial species detected, or the detection of Streptococcus pneumoniae, Moraxella catarrhalis, or Staphylococcus aureus. The results showed that 40% (95% CI 35%-47%) of the bacterial detections would have been missed if only high-quality samples were analyzed. This included 41% (27%-56%) of detections of S. pneumoniae, 33% (23%-45%) of detections of H. influenzae, 42% (28%-58%) of detections of S. aureus, and 37% (23%-54%) of detections of M. catarrhalis. These findings suggest that all sputum samples submitted for rapid syndromic PCR testing should be analyzed, regardless of initial microscopy quality assessment. (This study has been registered at ClinicalTrials.gov under registration no. NCT04660084.) IMPORTANCE Microscopic quality assessment of sputum samples was originally designed for sputum culture, and its applicability in today's workflow, which includes syndromic PCR testing, may differ. Addressing this crucial gap, our study emphasizes the need to optimize the use and workflow of syndromic PCR panels, like the BioFire FilmArray Pneumonia plus (FAP plus), in microbiology laboratories. These advanced PCR-based tests offer rapid and comprehensive pathogen detection for respiratory infections, yet their full potential remains uncertain. By comparing bacterial detections in high- and low-quality sputum samples, we underscore the importance of including low-quality samples in testing. Our findings reveal a significant proportion of potentially clinically relevant bacterial detections that would have been missed if only high-quality samples were analyzed. These insights support the efficient implementation of syndromic PCR panels, ultimately enhancing patient care and outcomes.

Supporting Clinical Decisions with Rapid Molecular Diagnostic Pneumonia Panel in Pediatric Intensive Care Unit: Single Center Experience in Turkiye

INTRODUCTION

Lower respiratory tract infections are the leading cause of morbidity and mortality in children worldwide. It is crucial to promptly conduct diagnostic investigations in order to determine the microbiological cause of pneumonia, since this is necessary to ensure the appropriate delivery of antibiotic therapy to each individual patient. We evaluated the results of a rapid molecular diagnostic pneumonia panel in children with LRTI in a pediatric intensive care unit (PICU).

PATIENTS AND METHODS

Rapid molecular diagnostic pneumonia panel (BioFire®, FilmArray Pneumonia Panel plus; FA-PP) findings (71 results from 46 children) in a tertiary care PICU between 2019 and 2023 were retrospectively reviewed.

RESULTS

At least one bacterial pathogen was detected in 57 cases. A total of 77% of children had underlying conditions. A total of 70.4% of children needed invasive mechanical ventilation and 54.4% had ventilator-associated pneumonia. Pseudomonas aeruginosa (50.8%), Acinetobacter calcoaceticus baumannii complex (42%), and Klebsiella pneumoniae (38.6%) were the most common pathogens detected with the FA-PP. Of the 33 cases diagnosed with VAP, more than one pathogen was identified in 65.9% of cases, with the most commonly identified bacteria being K. pneumoniae (43.1%), P. aeruginosa (38.6%), and Acinetobacter calcoaceticus baumannii complex (31.8%). According to the FA-PP results, the same antibiotic therapy was continued in 39.4% of cases, escalated in 54.5%, and de-escalated in 6.1%.

CONCLUSIONS

The utilization of the FA-PP has some beneficial effects, including more prompt delivery of findings compared to conventional approaches. Additionally, this approach enables the identification of resistance profiles in children diagnosed with pneumonia in the PICU. Consequently, these test results facilitate the organization of antibiotic treatment strategies, including escalation and de-escalation approaches. The detection of resistance patterns was exclusively determined via the implementation of molecular testing, prompting a reevaluation of the isolation technique in accordance with the obtained data.

Diagnostic utility of oropharyngeal swabs as an alternative to lower respiratory tract samples for PCR-based syndromic testing in patients with community-acquired pneumonia

Syndromic PCR-based analysis of lower respiratory tract (LRT) samples in patients with community-acquired pneumonia (CAP) improves the bacterial yield and time-to-results compared to culture-based methods. However, obtaining adequate sputum samples can be challenging and is frequently not prioritized in the emergency department (ED). In this study, we assess the concordance of microbiological detections between oropharyngeal- (OP) and LRT samples from patients presenting to the ED with CAP using a syndromic PCR-based respiratory panel [Biofire FilmArray Pneumonia plus (FAP plus)]. Paired OP- and high-quality LRT samples were collected from 103 patients with confirmed CAP, who had been included in a randomized controlled trial (NCT04660084) or a subsequent observational study at Haukeland University Hospital, and analyzed using the FAP plus. The LRT samples were obtained mainly by sputum induction (88%). Using the LRT samples as a reference standard, the positive percent agreement (PPA), negative percent agreement (NPA), and overall percent agreement for the most common bacterial pathogens in CAP, Streptococcus pneumoniae and Haemophilus influenzae, were 85%, 99% and 95%, and 86%, 98% and 93%, respectively. For Moraxella catarrhalis, the PPA was lower (74%), while the NPA was 100%. For bacteria that are less likely causes of uncomplicated CAP (e.g., Staphylococcus aureus and Enterobacterales) the results were more divergent. In conclusion, the FAP plus detects the most common CAP pathogens S. pneumoniae and H. influenzae from OP samples with high PPAs and excellent NPAs when compared with LRT samples. For these pathogens, the PPAs for OP samples were higher than previous reports for nasopharyngeal samples. This suggests that analysis of OP samples with syndromic PCR panels could represent an alternative approach for rapid microbiological testing in the ED, especially in patients where LRT samples are difficult to obtain. Divergent results for bacteria that are less likely to cause uncomplicated CAP do, however, emphasize the need for clinical evaluation of positive test results.

Assessing the Utility of Multiplexed Polymerase Chain Reaction in Detecting Microorganisms Causing Infections in Critically ill Patients

Early sepsis diagnosis is crucial for implementing adequate antibiotic therapy and for patient survival. This study investigated whether using multiplexed PCR for detecting microorganisms in critical septic patients affects initial antibiotic treatment and compared it to microbiological culture. It also explored scenarios where PCR is more effective in clinical practice. One hundred nineteen specimens (83 blood and 36 respiratory specimens) belonging to 93 patients were analyzed. Multiplexed PCR determinations were performed using the FA-BCID Panel (bioMérieux) for blood samples and the FA-Pneumo for respiratory samples. The mean turnaround times were 1.7 h for the FA-BCID and 1.5h for the FA-Pneumo. Conversely, they were 96.1 h for blood cultures and 72.3 h for respiratory cultures. FA-BCID showed a mean sensitivity of 97% and specificity of 100%. FA-Pneumo showed a sensitivity of 100% and specificity of 90%. However, the positive predictive value was only 39%. Discrepancies were common in polymicrobial samples. Based on the PCR results, initial empirical treatment should have been changed in 71% of patients with bloodstream infections and 61% with respiratory infections. We conclude that multiplexed PCR improves the response time in identifying germs with a high degree of coincidence for blood cultures and moderate for respiratory cultures. These results highlight the importance of PCR in choosing an appropriate antibiotic therapy.

Clinical Efficiency of Metagenomic Next-Generation Sequencing in Sputum for Pathogen Detection of Patients with Pneumonia According to Disease Severity and Host Immune Status

Purpose

Severe pneumonia causes the highest mortality rate in immunocompromised patients. This study aimed to investigate the pathogen diagnostic efficacy of metagenomic next-generation sequencing (mNGS) using sputum sample in patients with pneumonia according to patients' disease severity and immune conditions.

Patients and Methods

A total of 180 patients suffering from pneumonia were recruited, and sputum samples were collected in duplicate for pathogen detection by both conventional microbiological tests (CMT) and mNGS. Then, the performance of pathogen identification was examined between two methods, according to disease severity and patients' immune status.

Results

In comparison to CMT, mNGS had higher positivity rates in all patients with pneumonia (85.0% vs 62.2%, P=9.445e-07). The most commonly detected microorganism in sputum of pneumonia patients was Acinetobacter baumannii (42/180, 23.3%) in bacterum level, Candida albicans in fungus level (44/180, 24.4%), and Human herpesvirus 1 (39/180, 27.5%) in virus level. However, for mNGS results, Candida albicans in 34.9% of positive patients, and Human herpesvirus 1 in 7.7% of positive cases were confirmed as pathogens causing pneumonia. Acinetobacter baumannii detected by mNGS in 75% of positive patients was diagnosed as pathogen of pneumonia. The microorganism profile of sputum mNGS differed according to disease severity and immune status of patients. Pneumocystis jirovecii was more likely to infect immunocompromised patients (P=0.002). Pseudomonas aeruginosa (14.8% vs 0.0%, P=0.008) and Human herpesvirus 1 (26.1% vs 5.3%, P=0.004) had higher infection rate in patients with severe pneumonia compared with non-severe cases. mNGS had overwhelming advantages over CMT in detecting a lot of microorganisms including Streptococcus pneumoniae, Enterococcus faecium, Pneumocystis jirovecii, and majority of viruses.

Conclusion

mNGS is a complementary tool of CMT for detecting suspected pathogens for patients with lower respiratory infections. The interpretation of opportunistic pathogens identified by mNGS is challenging, and needs comprehensive consideration of sequencing data and clinical factors.

[Antibiotic treatment of community-acquired and hospital-acquired pneumonia]

Community-acquired and nosocomial bacterial pneumonia are among the most common infectious diseases in Germany. Knowledge of possible pathogens and therapeutic implications thereof are essential to be able to provide adequate, differentiated antimicrobial therapy with the appropriate drugs, form of application, dose, and duration. New diagnostics that include multiplex polymerase chain reaction, correct interpretation of the biomarker procalcitonin, and treatment of multidrug-resistant bacteria are becoming increasingly import.

Emerging Antimicrobial Resistance

The burden of emerging antimicrobial resistance (AMR) in the United States is significant and even greater worldwide. Mitigation efforts have decreased the incidence and deaths from antimicrobial-resistant organisms in the United States. Yet more than 2.8 million antimicrobial-resistant infections occur every year and more than 35,000 patients die as a result. Infection prevention and control, data tracking, antimicrobial stewardship, vaccines, therapeutics, diagnostics, and sanitation are all required to decrease AMR threats. In 2019, in the second version of the Centers for Disease Control and Prevention (CDC) report on antibiotic-resistant threats, the agency categorized AMR threats as urgent, serious, concerning, or to be watched. This review will discuss the following aspects of each bacterium in the CDC report: estimated numbers of cases and deaths, identify the better known and impactful mechanisms of resistance, diagnostic testing and its limitations, and current and possible future therapies. This review also presents anatomical pathology case examples that highlight the altered morphology of antibiotic partially treated bacteria in tissues.

Diagnostic accuracy of the BioFire® FilmArray® pneumonia panel in COVID-19 patients with ventilator-associated pneumonia

BACKGROUND

Ventilator-Associated pneumonia (VAP) is one of the leading causes of morbidity and mortality in critically ill COVID-19 patients in lower-and-middle-income settings, where timely access to emergency care and accurate diagnostic testing is not widely available. Therefore, rapid microbiological diagnosis is essential to improve effective therapy delivery to affected individuals, preventing adverse outcomes and reducing antimicrobial resistance.

METHODS

We conducted a cross-sectional study of patients with suspected VAP and COVID-19, evaluating the diagnostic performance of the BioFire® FilmArray® Pneumonia Panel (FA-PP). Respiratory secretion samples underwent standard microbiological culture and FA-PP assays, and the results were compared.

RESULTS

We included 252 samples. The traditional culture method detected 141 microorganisms, and FA-PP detected 277, resulting in a sensitivity of 95% and specificity of 60%, with a positive predictive value of 68% and negative predictive value of 93%. In samples with high levels of genetic material (> 10^5 copies/mL), the panel had a sensitivity of 94% and specificity of 86%. In addition, 40% of the culture-negative samples had positive FA-PP® results, of which 35% had > 10^5 copies/mL of genetic material. The most prevalent bacteria were Gram-negative bacilli, followed by Gram-positive cocci. The panel identified 98 genes associated with antimicrobial resistance, predominantly extended-spectrum beta-lactamases (28%).

CONCLUSION

The FA-PP is a sensitive assay for identifying bacteria causing VAP in patients with COVID-19, with a greater capacity to detect bacteria than the conventional method. The timely microbiological recognition offered by this panel could lead to optimized decision-making processes, earlier tailored treatment initiation, and improved antibiotic stewardship practices.

Implementation of a Rapid Multiplex Polymerase Chain Reaction Pneumonia Panel and Subsequent Antibiotic De-escalation

Background

Net effects of implementation of a multiplex polymerase chain reaction (PCR) pneumonia panel (PNP) on antimicrobial stewardship are thus far unknown. This retrospective study evaluated the real-world impact of the PNP on time to antibiotic de-escalation in critically ill patients treated for pneumonia at an academic medical center.

Methods

This retrospective, quasi-experimental study included adult intensive care unit (ICU) patients with respiratory culture results from 1 May to 15 August 2019 (pre-PNP group) and adult ICU patients with PNP results from 1 May to 15 August 2020 (PNP group) at Nebraska Medical Center. Patients were excluded for the following reasons: any preceding positive coronavirus disease 2019 PCR test, lack of antibiotic receipt, or non-respiratory tract infection indications for antibiotics. The primary outcome was time to discontinuation of anti-methicillin-resistant Staphylococcus aureus (MRSA) therapy. Secondary outcomes included time to discontinuation of antipseudomonal therapy, frequency of early discontinuation for atypical coverage, and overall duration (in days) of antibiotic therapy for pneumonia.

Results

Sixty-six patients in the pre-PNP group and 58 in the PNP group were included. There were significant differences in patient characteristics between groups. The median time to anti-MRSA agent discontinuation was 49.1 hours in the pre-PNP and 41.8 hours in the PNP group (P = .28). The median time to discontinuation of antipseudomonal agents was 134.4 hours in the pre-PNP versus 98.1 hours in the PNP group (P = .47). Other outcomes were numerically but not significantly improved in our sample.

Conclusions

This early look at implementation of a multiplex PNP did not demonstrate a statistically significant difference in antibiotic use but lays the groundwork to further evaluate a significant real-world impact on antibiotic de-escalation in ICU patients treated for pneumonia.

Recent updates in the development of molecular assays for the rapid identification and susceptibility testing of MRSA

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent cause of healthcare- and community-associated infections. Nasal carriage of MRSA is a risk factor for subsequent MRSA infections. Increased morbidity and mortality are associated with MRSA infections and screening and diagnostic tests for MRSA play an important role in clinical management.

AREAS COVERED

A literature search was conducted in PubMed and supplemented by citation searching. In this article, we provide a comprehensive review of molecular-based methods for MRSA screening and diagnostic tests including individual nucleic acid detection assays, syndromic panels, and sequencing technologies with a focus on their analytical performance.

EXPERT OPINION

Molecular based-assays for the detection of MRSA have improved in terms of accuracy and availability. Rapid turnaround enables earlier contact isolation and decolonization for MRSA. The availability of syndromic panel tests that include MRSA as a target has expanded from positive blood cultures to pneumonia and osteoarticular infections. Sequencing technologies allow detailed characterizations of novel methicillin-resistance mechanisms that can be incorporated into future assays. Next generation sequencing is capable of diagnosing MRSA infections that cannot be identified by conventional methods and metagenomic next-generation sequencing (mNGS) assays will likely move closer to implementation as front-line diagnostics in the near future.

Opportunities for Antimicrobial Stewardship Interventions Among Solid Organ Transplant Recipients

Although antimicrobial stewardship programs have excelled over the past decade, uptake and application of these programs to special populations such as solid organ transplant recipients have lagged. Here, we review the value of antimicrobial stewardship for transplant centers and highlight data supporting interventions that are ripe for adoption. In addition, we review the design of antimicrobial stewardship initiatives, targets for both syndromic and system-based interventions.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

PURPOSE

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and whilst European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

METHODS

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID, and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment, and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

ERS/ESICM/ESCMID/ALAT guidelines for the management of severe community-acquired pneumonia

BACKGROUND

Severe community-acquired pneumonia (sCAP) is associated with high morbidity and mortality, and while European and non-European guidelines are available for community-acquired pneumonia, there are no specific guidelines for sCAP.

MATERIALS AND METHODOLOGY

The European Respiratory Society (ERS), European Society of Intensive Care Medicine (ESICM), European Society of Clinical Microbiology and Infectious Diseases (ESCMID) and Latin American Thoracic Association (ALAT) launched a task force to develop the first international guidelines for sCAP. The panel comprised a total of 18 European and four non-European experts, as well as two methodologists. Eight clinical questions for sCAP diagnosis and treatment were chosen to be addressed. Systematic literature searches were performed in several databases. Meta-analyses were performed for evidence synthesis, whenever possible. The quality of evidence was assessed with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Evidence to Decision frameworks were used to decide on the direction and strength of recommendations.

RESULTS

Recommendations issued were related to diagnosis, antibiotics, organ support, biomarkers and co-adjuvant therapy. After considering the confidence in effect estimates, the importance of outcomes studied, desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention and implications to health equity, recommendations were made for or against specific treatment interventions.

CONCLUSIONS

In these international guidelines, ERS, ESICM, ESCMID and ALAT provide evidence-based clinical practice recommendations for diagnosis, empirical treatment and antibiotic therapy for sCAP, following the GRADE approach. Furthermore, current knowledge gaps have been highlighted and recommendations for future research have been made.

Gram-negative pulmonary infections - advances in epidemiology and diagnosis

PURPOSE OF REVIEW

Pulmonary infections due to Gram-negative organisms are increasing worldwide and traditional assumptions that these are limited to hospital and ventilator-acquired pneumonia are rapidly falling away. Accordingly, empiric antibiotic guidelines have to follow suit with ever broader spectrum choices in order to remain 'safe', as the Global prevalence of extensively resistant Gram-negative organisms inexorably increases. Rapid, multiplex PCR-based detection of a wide variety of potential pathogens offers the opportunity to replace empiric antibiotic choices with targeted, evidence-based therapy in clinically actionable timeframes.

RECENT FINDINGS

Here, we describe the data underpinning both the increasing global prevalence of Gram-negative pulmonary infections and their increasing antibiotic resistance. We also describe the performance, characteristics and early emerging clinical impact of already available rapid molecular diagnostic platforms and how they might best be deployed.

SUMMARY

It seems will likely be advantageous to replace the current trend for empiric prescription of increasingly broad-spectrum antibiotics with 'same day' evidence-based, targeted therapy using high performance, rapid molecular diagnostic solutions. Several challenges remain be overcome, however, to fully realize their clear potential for better, focussed deployment of antibiotics, improved patient outcomes and antibiotic stewardship.

Immunocompromised Host Pneumonia: Definitions and Diagnostic Criteria: An Official American Thoracic Society Workshop Report

Pneumonia imposes a significant clinical burden on people with immunocompromising conditions. Millions of individuals live with compromised immunity because of cytotoxic cancer treatments, biological therapies, organ transplants, inherited and acquired immunodeficiencies, and other immune disorders. Despite broad awareness among clinicians that these patients are at increased risk for developing infectious pneumonia, immunocompromised people are often excluded from pneumonia clinical guidelines and treatment trials. The absence of a widely accepted definition for immunocompromised host pneumonia is a significant knowledge gap that hampers consistent clinical care and research for infectious pneumonia in these vulnerable populations. To address this gap, the American Thoracic Society convened a workshop whose participants had expertise in pulmonary disease, infectious diseases, immunology, genetics, and laboratory medicine, with the goal of defining the entity of immunocompromised host pneumonia and its diagnostic criteria.

Impact of Culture-Positive Preservation Fluid on Early Morbidity and Mortality After Lung Transplantation

The prevalence, risk factors and outcomes associated with culture-positive preservation fluid (PF) after lung transplantation (LT) are unknown. From January 2015 to December 2020, the microbiologic analyses of PF used to store the cold ischaemia-placed lung graft(s) of 271 lung transplant patients were retrospectively studied. Culture-positive PF was defined as the growth of any microorganism. Eighty-three (30.6%) patients were transplanted with lung grafts stored in a culture-positive PF. One-third of culture-positive PF were polymicrobial. Staphylococcus aureus and Escherichia coli were the most frequently isolated microorganisms. No risk factors for culture-positive PF based on donor characteristics were identified. Forty (40/83; 48.2%) patients had postoperative pneumonia on Day 0 and 2 (2/83; 2.4%) patients had pleural empyema with at least one identical bacteria isolated in culture-positive PF. The 30-day survival rate was lower for patients with culture-positive PF compared with patients with culture-negative PF (85.5% vs. 94.7%, p = 0.01). Culture-positive PF has a high prevalence and may decrease lung transplant recipient survival. Further studies are required to confirm these results and improve understanding of the pathogenesis of culture-positive PF and their management.

Antimicrobial Stewardship Techniques for Critically Ill Patients with Pneumonia

Pneumonia is common in the intensive care unit (ICU), infecting 27% of all critically ill patients. Given the high prevalence of this disease state in the ICU, optimizing antimicrobial therapy while minimizing toxicities is of utmost importance. Inappropriate antimicrobial use can increase the risk of antimicrobial resistance, Clostridiodes difficile infection, allergic reaction, and other complications from antimicrobial use (e.g., QTc prolongation, thrombocytopenia). This review article aims to discuss methods to optimize antimicrobial treatment in patients with pneumonia, including the following: procalcitonin use, utilization of methicillin-resistant Staphylococcus aureus nares testing to determine need for vancomycin therapy, utilization of the Biofire^® FilmArray^® pneumonia polymerase chain reaction (PCR), and microbiology reporting techniques.

The Biofire® Filmarray® Pneumonia Plus panel for management of lower respiratory tract infection in mechanically-ventilated patients in the COVID-19 era: a diagnostic and cost-benefit evaluation

We assessed the diagnostic performance of the Biofire® Filmarray® Pneumonia Plus panel (FA-PP) compared to standard culture in Intensive Care Unit patients with suspected ventilator-associated lower respiratory tract infection in the COVID-19 era. We determined whether its implementation in routine diagnostic algorithms would be cost-beneficial from a hospital perspective. Of 163 specimens, 96 (59%) returned negative results with FA-PP and conventional culture, and 29 specimens (17.8%) were positive with both diagnostic methods and yielded concordant qualitative bacterial identification/isolation. Thirty-nine specimens (23.9%) gave discordant results (positive via FA-PP and negative via culture). Real-life adjustments of empirical antimicrobial therapy (EAT) after FA-PP results resulted in additional costs beyond EAT alone of 1868.7 €. Adequate EAT adjustments upon FA-PP results would have resulted in a saving of 6675.8 €. In conclusion, the data presented supports the potential utility of FA-PP for early EAT adjustment in patients with ventilator-associated lower respiratory tract infection.

Evaluation of Microbiological Concordance of a Rapid Molecular Diagnostic Pneumonia Panel in a Real-World Population with Pneumonia

BACKGROUND

The Biofire® FilmArray® Pneumonia Panel (PN Panel) provides a more rapid and sensitive method of respiratory pathogen detection than standard culture. However, it is often unclear how to apply the results clinically, especially in the case of discordant culture results. We evaluated the concordance of bacterial organism and resistance gene identification between the PN Panel and standard culture methods in hospitalized patients with a clinical diagnosis of pneumonia.

METHODS

This single-center retrospective observational study of 274 inpatients assessed the positive predictive value (PPV) and described the prevalence of individual bacterial organism and resistance marker targets on the PN Panel.

RESULTS

The overall PPV of the PN Panel in identifying bacteria was 70.1%, with individual organism PPV ranging from 50.0% to 90.9%. For resistance gene identification, the PN Panel's PPV ranged from 46.2% for CTX-M to 68.4% for mecA/C and the staphylococcal cassette chromosome mec element right extremity junction (MREJ), although resistance was uncommon. Staphylococcus aureus was the most common bacterial pathogen detected by the PN Panel (38.7%), followed by Pseudomonas aeruginosa (22.3%), and Haemophilus influenzae (12.0%).

CONCLUSIONS

The PN Panel detected more bacteria and resistance gene targets than standard culture methods. To optimize the use of this technology for both patient care and antimicrobial stewardship, results should be coupled with clinical assessment and clinician education.

The rapid detection of respiratory pathogens in critically ill children

PURPOSE

Respiratory infections are the most common reason for admission to paediatric intensive care units (PICU). Most patients with lower respiratory tract infection (LRTI) receive broad-spectrum antimicrobials, despite low rates of bacterial culture confirmation. Here, we evaluated a molecular diagnostic test for LRTI to inform the better use of antimicrobials.

METHODS

The Rapid Assay for Sick Children with Acute Lung infection Study was a single-centre, prospective, observational cohort study of mechanically ventilated children (> 37/40 weeks corrected gestation to 18 years) with suspected community acquired or ventilator-associated LRTI. We evaluated the use of a 52-pathogen custom TaqMan Array Card (TAC) to identify pathogens in non-bronchoscopic bronchoalveolar lavage (mini-BAL) samples. TAC results were compared to routine microbiology testing. Primary study outcomes were sensitivity and specificity of TAC, and time to result.

RESULTS

We enrolled 100 patients, all of whom were tested with TAC and 91 of whom had matching culture samples. TAC had a sensitivity of 89.5% (95% confidence interval (CI₉₅) 66.9-98.7) and specificity of 97.9% (CI₉₅ 97.2-98.5) compared to routine bacterial and fungal culture. TAC took a median 25.8 h (IQR 9.1-29.8 h) from sample collection to result. Culture was significantly slower: median 110.4 h (IQR 85.2-141.6 h) for a positive result and median 69.4 h (IQR 52.8-78.6) for a negative result.

CONCLUSIONS

TAC is a reliable and rapid adjunct diagnostic approach for LRTI in critically ill children, with the potential to aid early rationalisation of antimicrobial therapy.