Performance of a multiplex polymerase chain reaction panel for identifying bacterial pathogens causing pneumonia in critically ill patients with COVID-19

Epidemiology and prediction of non-targeted bacteria by the filmarray pneumonia plus panel in culture-positive ventilator-associated pneumonia: a retrospective multicentre analysis

BACKGROUND

Ventilator-associated pneumonia (VAP) is a prevalent nosocomial infection in intensive care units (ICUs) with significant impacts on patient outcomes and healthcare costs. Multiplex PCR could allow for personalized empirical treatment of VAP and optimize antibiotic therapy.

METHODS

This multicenter retrospective study analyzed culture-positive VAP cases from January 2016 to March 2021 across 12 ICUs in France. The prevalence of non-targeted bacteria was evaluated according to the bacterial species included in the BioFire® FilmArray® Pneumonia Panel (FAPPP), and associated risk factors were identified. A non-targeted bacteria was defined as a bacterial species isolated during VAP, not included in the FilmArray panel, but considered by the clinician in the final antibiotic therapy.

RESULTS

Among 332 patients with 385 culture-positive VAP episodes, non-targeted pathogens were observed in 23% of cases (87/385) and represented 21% (110/534) of isolated bacteria (After excluding bacteria with low pathogenicity, the rate of VAP with a non-targeted bacterium was 21%). The most common non-targeted bacteria identified were Stenotrophomonas maltophilia (22%), Citrobacter koseri, and Hafnia alvei. Gram stain results poorly correlated with definitive cultures (42% of concordance). The proportion of culture-positive VAP with non-targeted bacteria varied significantly between ICUs, ranging from 12 to 37%, (p = 0.013). Polymicrobial culture-positive VAP had a twofold higher risk of non-targeted bacteria (47% vs. 25%, p < 0.001). In the multivariate analysis, in-ICU antibiotic exposure was associated with a twofold increased risk of non-targeted bacteria (25.3% vs. 12.9%, p = 0.042), and age over 70 years was associated with a threefold increased risk (p = 0.027). Among the 48 culture-positive VAP cases with ineffective empiric treatment, Pseudomonas aeruginosa (22%), Stenotrophomonas maltophilia (14%), and Enterobacter cloacae complex (8%) were the most frequent bacteria. Additionally, 67% of the culture-positive VAP cases with ineffective empirical antibiotic therapy involved targeted bacteria, of which 59% could have received effective empirical antibiotic therapy if panel results had been available, according to bacterial species identification and current guidelines.

CONCLUSIONS

A significant rate of culture-positive VAP cases with non-targeted bacteria was observed in this study, raising concerns about the interpretation of FAPPP results. Only positive FAPPP results may assist clinicians in the early personalization of antibiotic therapy for VAP.

Synergistic effect between bacteriophages and nanozymes for hybrid dual recognition of pathogenic bacteria from water, food, and agricultural samples: promising new tools for sensitive and specific biosensing

Worldwide, pathogenic bacteria are among the most significant causes of infections. Indeed, delays in diagnosis and detection of these bacteria result in high morbidity and mortality rates and detection platforms must be developed to overcome these challenges. Biosensors, as high-potential analytical tools, can play an important role in the detection of pathogenic bacteria. The application of nanozymes as nanomaterial-based artificial enzymes in the structure of biosensors can overcome the limitations of common biological elements. Furthermore, the integration of bacteriophages, as novel bioreceptors, with nanozymes enabled a clear distinction between viable and dead bacteria. The application of bacteriophage-nanozyme as hybrid probes in biosensors can boost pathogenic bacteria detection. In this review, the effects of different nanozymes, including metal-based, metal oxide-based, and metal-organic framework (MOF)-based nanozymes, after integration with bacteriophages are discussed. Perspectives and challenges of a combination of these novel bioreceptors and nanomaterial-based artificial enzymes are presented for detecting various pathogenic bacteria.

Clinical and immunological comparison of COVID-19 disease between critical and non-critical courses: a systematic review and meta-analysis

Introduction

Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which appeared in 2019, has been classified as critical and non-critical according to clinical signs and symptoms. Critical patients require mechanical ventilation and intensive care unit (ICU) admission, whereas non-critical patients require neither mechanical ventilation nor ICU admission. Several factors have been recently identified as effective factors, including blood cell count, enzymes, blood markers, and underlying diseases. By comparing blood markers, comorbidities, co-infections, and their relationship with mortality, we sought to determine differences between critical and non-critical groups.

Method

We used Scopus, PubMed, and Web of Science databases for our systematic search. Inclusion criteria include any report describing the clinical course of COVID-19 patients and showing the association of the COVID-19 clinical courses with blood cells, blood markers, and bacterial co-infection changes. Twenty-one publications were eligible for full-text examination between 2019 to 2021.

Result

The standard difference in WBC, lymphocyte, and platelet between the two clinical groups was 0.538, -0.670, and -0.421, respectively. Also, the standard difference between the two clinical groups of CRP, ALT, and AST was 0.482, 0.402, and 0.463, respectively. The odds ratios for hypertension and diabetes were significantly different between the two groups. The prevalence of co-infection also in the critical group is higher.

Conclusion

In conclusion, our data suggest that critical patients suffer from a suppressed immune system, and the inflammation level, the risk of organ damage, and co-infections are significantly high in the critical group and suggests the use of bacteriostatic instead of bactericides to treat co-infections.

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.

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.

Coinfection of SARS-CoV-2 with other respiratory pathogens in outpatients from Ecuador

Worldwide, the COVID-19 pandemic caused by SARS-CoV-2 has enormously impacted healthcare systems, especially in low and middle-income countries. Coinfections with respiratory pathogens in COVID-19 patients may contribute to worse outcomes. This study identified the presence of 12 viral coinfections and pneumococcal carriers among individuals with SARS-CoV-2 infection in outpatient and community settings in Ecuador. From January 2020 to November 2021, 215 nasopharyngeal and nasal swabs were taken from individuals who reported symptoms of COVID-19 or had known exposure to someone with confirmed or suspected COVID-19. One hundred fifty-eight tested positive for SARS-CoV-2 by RT-qPCR and coinfections were detected in 12% (19/158) of SARS-CoV-2-positive patients; the most frequent coinfection was with influenza A virus at 4.4% (7/158; 95% CI: 1.2-7.6), followed by respiratory syncytial virus with 3.1% (5/158; 95% CI: 0.4-5.8), and finally rhinovirus and human coronavirus NL63 with 1.2% (2/158). Pneumococcal carriage was detected in 3.7% (6/158; 95% CI: 0.76-6.64) of SARS-CoV-2 cases. Influenza B, adenovirus, human metapneumovirus (HMPV), parainfluenza virus types 1, 2, and 3, and human coronavirus HKU1 were undetected. To our knowledge, this is the first study of coinfection of SARS-CoV-2 and respiratory pathogens performed on outpatients in Latin America. The high proportion of outpatients with viral coinfections reported in our cohort allows us to suggest that testing for SARS-CoV-2 and other common respiratory pathogens should be carried out to ensure accurate diagnoses, prompt patient treatment, and appropriate isolation.

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.

Fungal Infections Identified with Multiplex PCR in Severe COVID-19 Patients during Six Pandemic Waves

Background and Objectives: With an increasing number of severe COVID-19 cases presenting with secondary fungal infections, this study aimed to determine the prevalence of fungal co-infections in severe COVID-19 patients across the six waves, identify the most common fungal pathogens associated with severe COVID-19, and explore any potential links between patient characteristics, therapeutic strategies, and the prevalence and type of fungal infection. Materials and Methods: A retrospective analysis was conducted on severe COVID-19 patients admitted to the Infectious Diseases and Pulmonology Hospital, "Victor Babes", Romania, between March 2020 and August 2022. Samples were collected from respiratory specimens, blood, and urine, after which a standard nucleic acid extraction protocol was employed. Patients were divided into groups with and without fungal infections, identified using multiplex PCR. The groups were compared based on demographic data, comorbidities, pandemic wave number, and clinical outcomes. Results: Out of 288 patients, 96 (33.3%) had fungal infections, with Candida spp. being the most common. Patients with fungal infections had higher rates of obesity (35.4% vs. 21.4%, p = 0.010) and a higher Charlson comorbidity index (CCI > 2) (37.5% vs 25.0%, p = 0.027). Ventilator use was significantly higher in the fungal infection group (45.8% vs. 18.8%; p < 0.001), as was ICU admission (39.6% vs. 26.6%; p = 0.024) and mortality (32.3% vs 12.0%; p < 0.001). The distribution of different fungal species varied across the pandemic waves, with no statistical significance (p = 0.209). The mortality risk notably increased with the degree of drug resistance (OR for three or more drug resistances = 6.71, p < 0.001). The second, fourth, and fifth pandemic waves were significantly associated with higher mortality risk (OR = 3.72, 3.61, and 4.08, respectively, all p < 0.001). Aspergillus spp. and Mucor spp. infections were significantly associated with increased mortality risk (OR = 4.61 and 6.08, respectively, both p < 0.001). Conclusions: Our study indicates a significant presence of fungal co-infections among severe COVID-19 patients that is associated with increased morbidity and mortality, particularly in patients with drug-resistant infections. These findings underline the necessity for comprehensive diagnostic approaches and tailored treatment strategies in managing COVID-19 patients, especially during specific pandemic waves and in patients with particular fungal infections. Further research is required to understand the implications of these co-infections and their management.

Recommendations and guidelines for the diagnosis and management of Coronavirus Disease-19 (COVID-19) associated bacterial and fungal infections in Taiwan

Coronavirus disease-19 (COVID-19) is an emerging infectious disease caused by SARS-CoV-2 that has rapidly evolved into a pandemic to cause over 600 million infections and more than 6.6 million deaths up to Nov 25, 2022. COVID-19 carries a high mortality rate in severe cases. Co-infections and secondary infections with other micro-organisms, such as bacterial and fungus, further increases the mortality and complicates the diagnosis and management of COVID-19. The current guideline provides guidance to physicians for the management and treatment of patients with COVID-19 associated bacterial and fungal infections, including COVID-19 associated bacterial infections (CABI), pulmonary aspergillosis (CAPA), candidiasis (CAC) and mucormycosis (CAM). Recommendations were drafted by the 7th Guidelines Recommendations for Evidence-based Antimicrobial agents use Taiwan (GREAT) working group after review of the current evidence, using the grading of recommendations assessment, development, and evaluation (GRADE) methodology. A nationwide expert panel reviewed the recommendations in March 2022, and the guideline was endorsed by the Infectious Diseases Society of Taiwan (IDST). This guideline includes the epidemiology, diagnostic methods and treatment recommendations for COVID-19 associated infections. The aim of this guideline is to provide guidance to physicians who are involved in the medical care for patients with COVID-19 during the ongoing COVID-19 pandemic.

The Assessment of Multiplex PCR in Identifying Bacterial Infections in Patients Hospitalized with SARS-CoV-2 Infection: A Systematic Review

Bacterial infection can occur in patients hospitalized with SARS-CoV-2 in various conditions, resulting in poorer outcomes, such as a higher death rate. This current systematic review was conducted in order to assess the efficiency of multiplex PCR in detecting bacterial infections in hospitalized COVID-19 patients, as well as to analyze the most common bacterial pathogens and other factors that interfere with this diagnosis. The research was conducted using four electronic databases (PubMed, Taylor&Francis, Web of Science, and Wiley Online Library). Out of 290 studies, nine were included in the systematic review. The results supported the use of multiplex PCR in detecting bacteria, considering its high sensitivity and specificity rates. The most common bacterial pathogens found were Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Haemophilus influenzae. The median age at admission was 61.5 years, and the majority of patients were men (70.3%), out of a total of 1553 patients. The proportion of ICU admission was very high, with a pooled proportion of 52.6% over the analyzed studies, and an average duration of hospitalization of 13 days. The mortality rate was proportionally high, as was the rate of ICU admission, with a pooled mortality of 24.9%. It was discovered that 65.2% of all patients used antibiotics before admission, with or without medical prescription. Antibiotic treatment should be considered consciously, considering the high risks of developing antibiotic resistance.

Evaluation and Clinical Impact of Biofire FilmArray Pneumonia Panel Plus in ICU-Hospitalized COVID-19 Patients

Microbiological diagnosis by using commercial multiplex quantitative PCR systems provides great advantages over the conventional culture. In this work, the Biofire FilmArray Pneumonia Panel Plus (FAPP+) was used to test 144 low respiratory tract samples from 105 COVID-19 patients admitted to an Intensive Care Unit (ICU), detecting 78 pathogens in 59 (41%) samples. The molecular panel was evaluated by using the conventional culture (CC) as comparator, which isolated 42 pathogens in 40 (27.7%) samples. The overall percentage of agreement was 82.6%. Values of sensitivity (93%), specificity (62%), positive predictive value (50%), and negative predictive value (96%) were obtained. The mean time elapsed from sample extraction to modification of antibiotic treatment was 7.6 h. A change in antimicrobial treatment after the FAPP+ results was performed in 27% of patients. The FAPP+ is a highly sensitive diagnostic method that can be used to significantly reduce diagnostic time and that allows an early optimization of antimicrobial treatment.

Risk stratification for selecting empiric antibiotherapy during and after COVID-19

PURPOSE OF REVIEW

SARS-CoV-2 deeply modified the risk of bacterial infection, bacterial resistance, and antibiotic strategies. This review summarized what we have learned.

RECENT FINDINGS

During the COVID-19 pandemic, we observed an increase in healthcare-acquired infection and multidrug-resistant organism-related infection, triggered by several factors: structural factors, such as increased workload and ongoing outbreaks, underlying illnesses, invasive procedures, and treatment-induced immunosuppression. The two most frequently healthcare-acquired infections described in patients hospitalized with COVID-19 were bloodstream infection, related or not to catheters, health-acquired pneumonia (in ventilated or nonventilated patients). The most frequent species involved in bacteremia were Gram-positive cocci and Gram-negative bacilli in health-acquired pneumonia. The rate of Gram-negative bacilli is particularly high in late-onset ventilator-associated pneumonia, and the specific risk of Pseudomonas aeruginosa- related pneumonia increased when the duration of ventilation was longer than 7 days. A specificity that remains unexplained so far is the increase in enterococci bacteremia.

SUMMARY

The choice of empiric antibiotimicrobials depends on several factors such as the site of the infection, time of onset and previous length of stay, previous antibiotic therapy, and known multidrug-resistant organism colonization. Pharmacokinetics of antimicrobials could be markedly altered during SARS-CoV-2 acute respiratory failure, which should encourage to perform therapeutic drug monitoring.

Multiplex PCR in the empirical antibiotic treatment of patients with SARS-CoV-2 and bacterial respiratory superinfection

Background

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic led to overuse of antimicrobials, which increased concerns regarding antimicrobial resistance.

Objective

To measure the impact of a multiplex polymerase chain reaction (PCR) pneumonia panel on empirical antibiotic treatment for patients with critical coronavirus disease 2019 (COVID-19) with suspected bacterial respiratory superinfection.

Methods

This descriptive, prospective study was undertaken in a 36-bed intensive care unit from June 2020 to July 2021. Patients with severe COVID-19 who were ventilated and under suspicion of bacterial respiratory superinfection were included in the study. The intervention was a semi-quantitative multiplex PCR alongside concurrent standard cultures. When PCR panel results were expected to be obtained within 3 h of sampling, empirical antibiotic treatment was not administered while awaiting the results. Otherwise, empirical treatment was initiated. Patients classified as 'avoided empirical treatment' avoided 48-72 h of empirical antibiotic therapy. For those patients who received empirical treatment, the PCR panel results were used to decide whether treatment should be escalated, de-escalated, maintained or stopped. Positive and negative predictive values, and 'avoided empirical treatment' were calculated. Medical conduct and panel results were analysed for patients who received empirical treatment.

Results

Eighty-two patients (71% male, 29% female) were included in this study. The mean age was 57.5 years, and the mean APACHE II score was 16. Ninety PCR panels were performed, and the negative and positive predictive values were 99.9% and 66.7%, respectively. Empirical treatment was avoided in 61% of episodes. Of those patients who were receiving antibiotics when the PCR panel was performed, treatment was de-escalated in 71%, escalated in 14%, stopped in 9% and maintained in 6%. A diagnosis of bacterial respiratory superinfection was ruled out in 19% of cases.

Conclusions

PCR panels prevented the initiation of empirical antibiotic treatment in two-thirds of patients, and led to de-escalation in more than two-thirds of those who had started empirical antibiotic treatment. The high negative predictive value of the PCR panel allowed the diagnosis of bacterial respiratory superinfection to be ruled out. This tool represents a significant contribution to diagnostic stewardship in order to avoid the unnecessary use of antibiotics.

Performance of PCR-based syndromic testing compared to bacterial culture in patients with suspected pneumonia applying microscopy for quality assessment

Syndromic testing for lower respiratory tract infections with BioFire® FilmArray® Pneumonia Panel Plus (BF) detects 27 pathogens with a turn-around-time of one hour. We compared the performance of BF with culture. Samples from 298 hospitalized patients with suspected pneumonia routinely sent for culture were also analyzed using BF. Retrospectively, patients were clinically categorized as having "pneumonia" or "no pneumonia." BF and culture were compared by analytical performance, which was evaluated by pathogen concordance, and by clinical performance by comparing pathogen detections in patients with and without pneumonia. The BF results for viruses and atypical bacteria were not included in the performance analysis. In 298 patient samples, BF and culture detected 285 and 142 potential pathogens, respectively. Positive percent agreement (PPA) was 88% (125/142). In patients with community-acquired pneumonia (CAP), clinical sensitivity was 70% and 51%, and specificity was 43% and 71% for BF and culture, respectively. In patients with hospital-acquired pneumonia, the corresponding numbers were 55% and 23%, and 47% and 68%. There was no significant improvement of performance, when only high-quality sputum samples were considered. Efficacy of both BF and culture was low. Both tests are best used in CAP patients for whom the diagnosis has already been clinically established. Indiscriminate use may be clinically misleading and a cause of improper use of antibiotics.

Diagnostic concordance between BioFire® FilmArray® Pneumonia Panel and culture in patients with COVID-19 pneumonia admitted to intensive care units: the experience of the third wave in eight hospitals in Colombia

Background

The detection of coinfections is important to initiate appropriate antimicrobial therapy. Molecular diagnostic testing identifies pathogens at a greater rate than conventional microbiology. We assessed both bacterial coinfections identified via culture or the BioFire® FilmArray® Pneumonia Panel (FA-PNEU) in patients infected with SARS-CoV-2 in the ICU and the concordance between these techniques.

Methods

This was a prospective study of patients with SARS-CoV-2 who were hospitalized for no more than 48 h and on mechanical ventilation for no longer than 24 h in 8 ICUs in Medellín, Colombia. We studied mini-bronchoalveolar lavage or endotracheal aspirate samples processed via conventional culture and the FA-PNEU. Coinfection was defined as the identification of a respiratory pathogen using the FA-PNEU or cultures. Serum samples of leukocytes, C-reactive protein, and procalcitonin were taken on the first day of intubation. We analyzed the empirical antibiotics and the changes in antibiotic management according to the results of the FA-PNEUM and cultures.

Results

Of 110 patients whose samples underwent both methods, FA-PNEU- and culture-positive samples comprised 24.54% versus 17.27%, respectively. Eighteen samples were positive in both techniques, 82 were negative, 1 was culture-positive with a negative FA-PNEU result, and 9 were FA-PNEU-positive with negative culture. The two bacteria most frequently detected by the FA-PNEU were Staphylococcus aureus (37.5%) and Streptococcus agalactiae (20%), and those detected by culture were Staphylococcus aureus (34.78%) and Klebsiella pneumoniae (26.08%). The overall concordance was 90.1%, and when stratified by microorganism, it was between 92.7 and 100%. The positive predictive value (PPV) was between 50 and 100% and were lower for Enterobacter cloacae and Staphylococcus aureus. The negative predictive value (NPV) was high (between 99.1 and 100%); MecA/C/MREJ had a specificity of 94.55% and an NPV of 100%. The inflammatory response tests showed no significant differences between patients whose samples were positive and negative for both techniques. Sixty-one patients (55.45%) received at least one dose of empirical antibiotics.

Conclusions

The overall concordance was 90.1%, and it was between 92.7% and 100% when stratified by microorganisms. The positive predictive value was between 50 and 100%, with a very high NPV.

Potential Impact of Rapid Multiplex PCR on Antimicrobial Therapy Guidance for Ventilated Hospital-Acquired Pneumonia in Critically Ill Patients, A Prospective Observational Clinical and Economic Study

Objectives

To investigate the potential impact of the syndromic multiplex FilmArray® Pneumonia plus Panel (FAPP) on the antimicrobial treatment guidance of patients with ventilated hospital-acquired pneumonia (VHAP).

Methods

Respiratory fluids from 100 adult patients with VHAP, receiving invasive mechanical ventilation in three intensive care units from one French university hospital, were tested prospectively using FAPP. Conventional cultures were performed in parallel as routine practice. Clinicians were left blinded to the FAPP results. Antimicrobial therapies based on FAPP results were simulated by independent blinded experts according to a predefined algorithm and compared to 1) those prescribed in practice according to local guidelines (real-life), and 2) those that complied with the international ERS/ESICM/ESCMID/ALAT recommendations. The primary endpoint was the number of days of broad-spectrum antimicrobial therapy. Secondary endpoints were the rates of microbiological treatment failure and cost-effectiveness ratio.

Results

The predicted median duration of broad-spectrum antibiotics was 0 [0-1.25] day in the FAPP-based simulation, versus 2 [0-6] days in real-life (p&lt;0.0001) and 2 [2-3.25] days in the recommendations-based simulation (p&lt;0.0001). Treatment failure was predicted in 3% of cases with FAPP results versus observed in 11% in real-life (p=0.08) and 6% with recommendations-based simulation (p=0.37). The incremental cost-effectiveness ratio was 1 121 € [-7021; 6794] to avoid one day of non-optimized antimicrobial therapy.

Conclusions

Our results suggest that using FAPP in patients with VHAP has the potential to reduce the use of broad-spectrum antimicrobial therapy without increasing the risk of microbial treatment failure.

Methicillin-resistant Staphylococcus aureus lung infection in coronavirus disease 2019: how common?

PURPOSE OF REVIEW

Some patients with coronavirus disease 2019 (COVID-19) may develop pulmonary bacterial coinfection or superinfection, that could unfavorably impact their prognosis.

RECENT FINDINGS

The exact burden of methicillin-resistant Staphylococcus aureus (MRSA) lung infection in peculiar populations such as patients with COVID-19 remains somewhat elusive, possibly because of wide heterogeneity in methods and endpoints across studies.

SUMMARY

There was important heterogeneity in the retrieved literature on the epidemiology of MRSA lung infection in patients with COVID-19, both when considering all other bacteria as the denominator (relative prevalence ranging from 2% to 29%) and when considering only S. aureus as the denominator (relative prevalence ranging from 11% to 65%). Overall, MRSA is among the most frequent causative agents of pulmonary infection in patients with COVID-19. Improving our ability to rapidly reach etiological diagnosis of bacterial lung infection in COVID-19 patients remains fundamental if we are to improve the rates of appropriate antibiotic therapy in patients with COVID-19 and concomitant/superimposed MRSA infection, at the same time avoiding antibiotic overuse in line with antimicrobial stewardship principles.

How common is ventilator-associated pneumonia after coronavirus disease 2019?

PURPOSE OF REVIEW

The first studies on COVID-19 patients with acute respiratory distress syndrome (ARDS) described a high rate of secondary bacterial ventilator-associated pneumonia (VAP). The specificity of VAP diagnoses in these patients are reviewed, including their actual rate.

RECENT FINDINGS

Published studies described high rates of bacterial VAP among COVID-19 patients with ARDS, and these VAP episodes are usually severe and of specifically poor prognosis with high mortality. Indeed, Severe acute respiratory syndrome - coronavirus disease 19 (SARS-CoV2) infection elicits alterations that may explain a high risk of VAP. In addition, breaches in the aseptic management of patients might have occurred when the burden of care was heavy. In addition, VAP in these patients is more frequently suspected, and more often investigated with diagnostic tools based on molecular techniques.

SUMMARY

VAP is frequented and of particularly poor prognosis in COVID-19 patients with ARDS. It can be explained by SARS-CoV-2 pathophysiology, and also breaches in the aseptic procedures. In addition, tools based on molecular techniques allow an early diagnosis and unmask VAP usually underdiagnosed by traditional culture-based methods. The impact of molecular technique-based diagnostics in improving antibacterial therapy and COVID-19 prognosis remain to be evaluated.

Empiric Treatment in HAP/VAP: “Don’t You Want to Take a Leap of Faith?”

Ventilator-associated pneumonia is a frequent cause of ICU-acquired infections. These infections are associated with high morbidity and mortality. The increase in antibiotic resistance, particularly among Gram-negative bacilli, makes the choice of empiric antibiotic therapy complex for physicians. Multidrug-resistant organisms (MDROs) related infections are associated with a high risk of initial therapeutic inadequacy. It is, therefore, necessary to quickly identify the bacterial species involved and their susceptibility to antibiotics. New diagnostic tools have recently been commercialized to assist in the management of these infections. Moreover, the recent enrichment of the therapeutic arsenal effective on Gram-negative bacilli raises the question of their place in the therapeutic management of these infections. Most national and international guidelines recommend limiting their use to microbiologically documented infections. However, many clinical situations and, in particular, the knowledge of digestive or respiratory carriage by MDROs should lead to the discussion of the use of these new molecules, especially the new combinations with beta-lactamase inhibitors in empirical therapy. In this review, we present the current epidemiological data, particularly in terms of MDRO, as well as the clinical and microbiological elements that may be taken into account in the discussion of empirical antibiotic therapy for patients managed for ventilator-associated pneumonia.

Diagnosis and Treatment of Bacterial Pneumonia in Critically Ill Patients with COVID-19 Using a Multiplex PCR Assay: A Large Italian Hospital's Five-Month Experience

Bacterial pneumonia is a challenging coronavirus disease 2019 (COVID-19) complication for intensive care unit (ICU) clinicians. Upon its implementation, the FilmArray pneumonia plus (FA-PP) panel's practicability for both the diagnosis and antimicrobial therapy management of bacterial pneumonia was assessed in ICU patients with COVID-19. Respiratory samples were collected from patients who were mechanically ventilated at the time bacterial etiology and antimicrobial resistance were determined using both standard-of-care (culture and antimicrobial susceptibility testing [AST]) and FA-PP panel testing methods. Changes to targeted and/or appropriate antimicrobial therapy were reviewed. We tested 212 samples from 150 patients suspected of bacterial pneumonia. Etiologically, 120 samples were positive by both methods, two samples were culture positive but FA-PP negative (i.e., negative for on-panel organisms), and 90 were negative by both methods. FA-PP detected no culture-growing organisms (mostly Staphylococcus aureus or Pseudomonas aeruginosa) in 19 of 120 samples or antimicrobial resistance genes in two culture-negative samples for S. aureus organisms. Fifty-nine (27.8%) of 212 samples were from empirically treated patients. Antibiotics were discontinued in 5 (33.3%) of 15 patients with FA-PP-negative samples and were escalated/deescalated in 39 (88.6%) of 44 patients with FA-PP-positive samples. Overall, antibiotics were initiated in 87 (72.5%) of 120 pneumonia episodes and were not administered in 80 (87.0%) of 92 nonpneumonia episodes. Antimicrobial-resistant organisms caused 78 (60.0%) of 120 episodes. Excluding 19 colistin-resistant Acinetobacter baumannii episodes, AST confirmed appropriate antibiotic receipt in 101 (84.2%) of 120 episodes for one or more FA-PP-detected organisms. Compared to standard-of-care testing, the FA-PP panel may be of great value in the management of COVID-19 patients at risk of developing bacterial pneumonia in the ICU. IMPORTANCE Since bacterial pneumonia is relatively frequent, suspicion of it in COVID-19 patients may prompt ICU clinicians to overuse (broad-spectrum) antibiotics, particularly when empirical antibiotics do not cover the suspected pathogen. We showed that a PCR-based, culture-independent laboratory assay allows not only accurate diagnosis but also streamlining of antimicrobial therapy for bacterial pneumonia episodes. We report on the actual implementation of rapid diagnostics and its real-life impact on patient treatment, which is a gain over previously published studies on the topic. A better understanding of the role of that or similar PCR assays in routine ICU practice may lead us to appreciate the effectiveness of their implementation during the COVID-19 pandemic.

Identification of bacterial co-detections in COVID-19 critically Ill patients by BioFire® FilmArray® pneumonia panel: a systematic review and meta-analysis

Among critically ill COVID-19 patients, bacterial coinfections may occur, and timely appropriate therapy may be limited with culture-based microbiology due to turnaround time and diagnostic yield challenges (e.g. antibiotic pre-exposure). We performed a systematic review and meta-analysis of the impact of BioFire® FilmArray® Pneumonia Panel in detecting bacteria and clinical management among critically ill COVID-19 patients admitted to the ICU. Seven studies with 558 patients were included. Antibiotic use before respiratory sampling occurred in 28-79% of cases. The panel incidence of detections was 33% (95% CI 0.25 to 0.41, I²=32%) while culture yielded 18% (95% CI 0.02 to 0.45; I²=93%). The panel was associated with approximately a 1 and 2 day decrease in turnaround for identification and common resistance targets, respectively. The panel may be an important tool for clinicians to improve antimicrobial use in critically ill COVID-19 patients.

Rapid identification of bacteria from respiratory samples of patients hospitalized in intensive care units, with FilmArray Pneumonia Panel Plus

OBJECTIVES

This study aimed to evaluate the performance of FilmArray Pneumonia Panel Plus (FA-PP) for the detection of typical bacterial pathogens in respiratory samples from patients hospitalized in intensive care units (ICUs).

METHODS

FA-PP was implemented for clinical use in the microbiology laboratory in March 2020. A retrospective analysis on a consecutive cohort of adult patients hospitalized in ICUs between March 2020 and May 2020 was undertaken. The respiratory samples included sputum, blind bronchoalveolar lavage (BBAL) and protected specimen brush (PSB). Conventional culture and FA-PP were performed in parallel.

RESULTS

In total, 147 samples from 92 patients were analysed; 88% had coronavirus disease 2019 (COVID-19). At least one pathogen was detected in 46% (68/147) of samples by FA-PP and 39% (57/147) of samples by culture. The overall percentage agreement between FA-PP and culture results was 98% (93-100%). Bacteria with semi-quantitative FA-PP results ≥10⁵ copies/mL for PSB samples, ≥10⁶ copies/mL for BBAL samples and ≥10⁷ copies/mL for sputum samples reached clinically significant thresholds for growth in 90%, 100% and 91% of cultures, respectively. FA-PP detected resistance markers, including mecA/C, bla_CTX-M and bla_VIM. The median turnaround time was significantly shorter for FA-PP than for culture.

CONCLUSIONS

FA-PP may constitute a faster approach to the diagnosis of bacterial pneumonia in patients hospitalized in ICUs.

Respiratory bacterial co-infections in intensive care unit-hospitalized COVID-19 patients: Conventional culture vs BioFire FilmArray pneumonia Plus panel

The prevalence and microbiology of concomitant respiratory bacterial infections in patients with SARS-CoV-2 infection are not yet fully understood. In this retrospective study, we assessed respiratory bacterial co-infections in lower respiratory tract samples taken from intensive care unit-hospitalized COVID-19 patients, by comparing the conventional culture approach to an innovative molecular diagnostic technology.

A total of 230 lower respiratory tract samples (i.e., bronchial aspirates or bronchoalveolar lavages) were taken from 178 critically ill COVID-19 patients. Each sample was processed by a semi-quantitative culture and by a multiplex PCR panel (FilmArray Pneumonia Plus panel), allowing rapid detection of a wide range of clinically relevant pathogens and a limited number of antimicrobial resistance markers.

More than 30% of samples showed a positive bacterial culture, with Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus the most detected pathogens.

FilmArray showed an overall sensitivity and specificity of 89.6% and 98.3%, respectively, with a negative predictive value of 99.7%. The molecular test significantly reduced the turn-around-time (TAT) and increased the rates of microbial detection. Most cases missed by culture were characterized by low bacterial loads (10⁴–10⁵ copies/mL). FilmArray missed a list of pathogens not included in the molecular panel, especially Stenotrophomonas maltophilia (8 cases).

FilmArray can be useful to detect bacterial pathogens in lower respiratory tract specimens of COVID-19 patients, with a significant decrease of TAT. The test is particularly useful to rule out bacterial co-infections and avoid the inappropriate prescription of antibiotics.

Bacterial coinfections in coronavirus disease 2019

Bacterial coinfections increase the severity of respiratory viral infections and were frequent causes of mortality in influenza pandemics but have not been well characterized in patients with coronavirus disease 2019 (COVID-19). The aim of this review was to identify the frequency and microbial etiologies of bacterial coinfections that are present upon admission to the hospital and that occur during hospitalization for COVID-19. We found that bacterial coinfections were present in <4% of patients upon admission and the yield of routine diagnostic tests for pneumonia was low. When bacterial coinfections did occur, Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae were the most common pathogens and atypical bacteria were rare. Although uncommon upon admission, bacterial infections frequently occurred in patients with prolonged hospitalization, and Pseudomonas aeruginosa, Klebsiella spp., and S. aureus were common pathogens. Antibacterial therapy and diagnostic testing for bacterial infections are unnecessary upon admission in most patients hospitalized with COVID-19, but clinicians should be vigilant for nosocomial bacterial infections.

Applying the lessons learned from coronavirus disease 2019 to improve pneumonia management

PURPOSE OF REVIEW

Coronavirus disease 2019 (COVID-19) has produced an extraordinary amount of literature in a short time period. This review focuses on what the new literature has provided in terms of more general information about the management of community-acquired pneumonia (CAP).

RECENT FINDINGS

Measures taken to reduce the spread of COVID-19 have caused a significant drop in influenza worldwide. Improvements in imaging, especially ultrasound, and especially in the application of rapid molecular diagnosis are likely to have significant impact on the management of CAP. Therapeutic advances are so far limited.

SUMMARY

COVID-19 has taught us that we can do far more to prevent seasonal influenza and its associated mortality, morbidity and economic cost. Improvements in imaging and pathogen diagnosis are welcome, as is the potential for secondary benefits of anti-COVID-19 therapies that may have reach effect on respiratory viruses other than severe acute respiratory syndrome coronavirus 2. As community-transmission is likely to persist for many years, recognition and treatment of severe acute respiratory syndrome coronavirus 2 will need to be incorporated into CAP guidelines moving forward.

Bacterial pulmonary superinfections are associated with longer duration of ventilation in critically ill COVID-19 patients

The impact of secondary bacterial infections (superinfections) in coronavirus disease 2019 (COVID-19) is not well understood. In this prospective, monocentric cohort study, we aim to investigate the impact of superinfections in COVID-19 patients with acute respiratory distress syndrome. Patients are assessed for concomitant microbial infections by longitudinal analysis of tracheobronchial secretions, bronchoalveolar lavages, and blood cultures. In 45 critically ill patients, we identify 19 patients with superinfections (42.2%). Superinfections are detected on day 10 after intensive care admission. The proportion of participants alive and off invasive mechanical ventilation at study day 28 (ventilator-free days [VFDs] at 28 days) is substantially lower in patients with superinfection (subhazard ratio 0.37; 95% confidence interval [CI] 0.15–0.90; p = 0.028). Patients with pulmonary superinfections have a higher incidence of bacteremia, virus reactivations, yeast colonization, and required intensive care treatment for a longer time. Superinfections are frequent and associated with reduced VFDs at 28 days despite a high rate of empirical antibiotic therapy.

Secondary bacterial infections (superinfections) are found in 42% of patients

Bacterial superinfections occur on day 10 after intensive care admission

Bacterial superinfections are associated with longer duration of ventilation

Bacterial superinfections are mostly caused by Gram-negative bacteria