Airway Bacterial Colonization, Biofilms and Blooms, and Acute Respiratory Infection

Detecting Respiratory Pathogens for Diagnosing Lower Respiratory Tract Infections at the Point of Care: Challenges and Opportunities

Lower respiratory tract infections (LRTIs) are a leading cause of mortality worldwide, claiming millions of lives each year and imposing significant healthcare costs. Accurate detection of respiratory pathogens is essential for the effective management of LRTIs. However, this process often relies on sputum analysis, which requires extensive pretreatment steps. The viscous nature and complex composition of sputum present additional challenges, especially in settings where a rapid diagnosis at the point of care is essential. In this review, we describe the main types of LRTI, highlighting different patient care pathway and points of care. We review current methods for liquefying sputum samples and provide an overview of current commercially available diagnostic tools used in hospitals for LRTI detection. Furthermore, we critically review recent advancements in the literature focused on detecting respiratory pathogens and mechanisms of antimicrobial resistance in sputum, including nucleic acid amplification tests, immunoassays and other innovative approaches. Throughout the paper, we highlight challenges and opportunities associated with developing new biosensor technologies tailored for detecting respiratory pathogens in lower respiratory specimens. By shedding light on these pressing issues, we aim to inspire scientific community to create innovative diagnostic tools to address the urgent healthcare burden of lung diseases.

Antimicrobial Resistance Patterns and Biofilm Analysis via Sonication in Intensive Care Unit Patients at a County Emergency Hospital in Romania

Background/Objectives: Ventilator-associated pneumonia (VAP) remains a critical challenge in ICU settings, often driven by the biofilm-mediated bacterial colonization of endotracheal tubes (ETTs). This study investigates antimicrobial resistance patterns and biofilm dynamics in ICU patients, focusing on microbial colonization and resistance trends in tracheal aspirates and endotracheal tube biofilms at a county emergency hospital in Romania. Methods: We conducted a longitudinal analysis of ICU patients requiring mechanical ventilation for more than 48 h. Tracheal aspirates and ETT biofilms were collected at three key time points: T1 (baseline), T2 (48 h post-intubation with ETT replacement), and T3 (92-100 h post-T2); these were analyzed using sonication and microbiological techniques to assess microbial colonization and antimicrobial resistance patterns. Results: In a total of 30 patients, bacteria from the ESKAPEE group (e.g., Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus) dominated the microbiota, increasing their prevalence over time. Resistance to carbapenems, colistin, and vancomycin was notably observed, particularly among K. pneumoniae and A. baumannii. Biofilm analysis revealed high persistence rates and the emergence of multidrug-resistant strains, underscoring the role of ETTs as reservoirs for resistant pathogens. The replacement of ETTs at T2 correlated with a shift in microbial composition and reduced biofilm-associated contamination. Conclusions: This study highlights the temporal evolution of antimicrobial resistance and biofilm-associated colonization in a limited number of ICU patients (30 patients). The findings support implementing routine ETT management strategies, including scheduled replacements and advanced biofilm-disruption techniques, to mitigate VAP risk and improve patient outcomes.

Antibiotic Choice and Outcomes for Respiratory Infections in Children With Tracheostomies

OBJECTIVE

Respiratory infections are a major cause of hospitalization in children with tracheostomies, contributing significantly to hospital expenses. Limited data exist to describe optimal diagnostic strategies or management recommendations for these infections. This study aimed to explore factors associated with antibiotic therapy, including usage, administration route, duration, variables influencing the decision to prescribe antibiotics, and outcomes in children with tracheostomies experiencing episodes of respiratory infection other than pneumonia (tracheobronchitis and nonspecific respiratory episodes [NSRE]).

METHODS

We conducted a retrospective cohort study using the medical records of 83 children who underwent tracheostomy and received treatment at a tertiary hospital from 2010 to 2021.

RESULTS

A total of 164 episodes of tracheobronchitis and 98 episodes of NSRE were analyzed. Children with tracheobronchitis were more frequently treated with antibiotics: 75% in nonhospitalized cases and 76% in hospitalized cases. In NSRE, antibiotic prescription dropped to 40% and 29%, respectively. Out of 51 tracheobronchitis and 15 NSRE initially treated with oral antibiotics, a switch to intravenous administration was deemed necessary in only 7 tracheobronchitis cases (14%). Fever was significantly associated with antibiotic prescription in tracheobronchitis and NSRE, regardless of hospitalization status. Two children died within the 28-day period following the onset of tracheobronchitis symptoms.

CONCLUSIONS

Many cases identified as tracheobronchitis, along with a greater number of NSRE cases, resolved without requiring antibiotics. Although fever was associated with increased antibiotic prescription, it does not necessarily indicate severity. Therefore, careful consideration should be given before prescribing antibiotics, especially in febrile cases, to avoid unnecessary treatments.

Current strategies for monitoring and controlling bacterial biofilm formation on medical surfaces

Biofilms, intricate microbial communities that attach to surfaces, especially medical devices, form an exopolysaccharide matrix, which enables bacteria to resist environmental pressures and conventional antimicrobial agents, leading to the emergence of multi-drug resistance. Biofilm-related infections associated with medical devices are a significant public health threat, compromising device performance. Therefore, developing effective methods for supervising and managing biofilm growth is imperative. This in-depth review presents a systematic overview of strategies for monitoring and controlling bacterial biofilms. We first outline the biofilm creation process and its regulatory mechanisms. The discussion then progresses to advancements in biosensors for biofilm detection and diverse treatment strategies. Lastly, this review examines the obstacles and new perspectives associated with this domain to facilitate the advancement of innovative monitoring and control solutions. These advancements are vital in combating the spread of multi drug-resistant bacteria and mitigating public health risks associated with infections from biofilm formation on medical instruments.

Quality Improvement Project Reducing Sputum Cultures for Pediatric Patients With a Tracheostomy

BACKGROUND AND OBJECTIVES

Current research implies overuse of diagnostic testing and overtreatment in children with tracheostomies. There are no guidelines for obtaining sputum cultures for these patients, yet they are commonly obtained without significantly affecting management or outcomes. The aim of our quality improvement project was to decrease rate of sputum cultures in this population by 50%, from 64% to 32%.

METHODS

This was a single-center quality improvement project conducted in a pediatric emergency department (ED). Key drivers included: Standardized decision-making, appropriate culture collection, knowledge regarding colonization versus clinically relevant growth, and viral versus bacterial infections in this population. The study team developed an algorithm, used modification to electronic medical records orders, and provided education to drive change. Six months of preintervention and 12 months postintervention data were collected. Run charts/statistical process charts were created for the rate of cultures, length of stay, and return to the ED.

RESULTS

There were 159 patient encounters and the rate of sputum cultures decreased from 64% at baseline to 25% without change in length of stay or increased rate at which patients returned to the ED, including during local coronavirus disease 2019 and respiratory syncytial virus surges. We observed nonrandom data patterns after introduction of algorithm resulting in centerline shifts.

CONCLUSIONS

The study team was able to introduce an algorithm coinciding with a reduction in number of sputum cultures obtained. Next steps would be determining safety and efficacy of such an algorithm over a larger population.

Respiratory culture organism isolation and test characteristics in children with tracheostomies with and without acute respiratory infection

BACKGROUND

Among children with tracheostomies, little is known about how respiratory culture results differ between states with and without acute respiratory infections (ARI), or the overall test performance of respiratory cultures.

OBJECTIVE

To determine the association of respiratory culture organism isolation with diagnosis of ARI in children with tracheostomies, and assess test characteristics of respiratory cultures in the diagnosis of bacterial ARI (bARI).

METHODS

This single-center, retrospective cohort study included respiratory cultures of children with tracheostomies obtained between 2010 and 2018. The primary predictor was ARI diagnosis code at the time of culture; the primary outcomes were respiratory culture organism isolation and species identified. Generalized estimating equations were used to assess for association between ARI diagnosis and isolation of any organism while controlling for potential confounders and accounting for within-patient clustering. A multinomial logistic regression equation assessed for association with specific species. Test characteristics were calculated using bARI diagnosis as the reference standard.

RESULTS

Among 3578 respiratory cultures from 533 children (median 4 cultures/child, interquartile range (IQR): 1-9), 25.9% were obtained during ARI and 17.2% had ≥1 organism. Children with ARI diagnosis had higher odds of organism identification (adjusted odds ratio 1.29, 95%  confidence interval [CI] 1.16-1.44). When controlling for covariates, ARI was associated with isolation of Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Streptococcus pyogenes. Test characteristics revealed a 24.3% sensitivity, 85.2% specificity, 36.5% positive predictive value, and 76.3% negative predictive value in screening for bARI.

CONCLUSION

The utility of respiratory culture testing to screen for, diagnose, and direct treatment of ARI in children with tracheostomies is limited.