Community-Acquired Thoracic Empyema in Older People

Integrating 16S rRNA profiling and in-silico analysis for an epitope-based vaccine strategy against Achromobacter xylosoxidans infection

Achromobacter xylosoxidans is an aerobic, catalase-positive, non-pigment-forming, Gram-negative, and motile bacterium. It potentially causes a wide range of human infections in cystic fibrosis and non-cystic fibrosis patients. However, developing a safe preventive or therapeutic solution against A. xylosoxidans remains challenging. This study aimed to construct an epitope-based vaccine candidate using immunoinformatic techniques. A. xylosoxidans was isolated from an auto workshop in Lahore, and its identification was confirmed through 16S rRNA amplification and bioinformatic analysis. Two protein targets with GenBank accession numbers AKP90890.1 and AKP90355.1 were selected for the vaccine construct. Both proteins exhibited antigenicity, with scores of 0.757 and 0.580, respectively and the epitopes were selected based on the IC50 value using the ANN 4.0 and NN-align 2.3 epitope prediction method for MHC I and MHC II epitopes respectively and predicted epitopes were analyzed for antigenicity, allergenicity and pathogenicity. The vaccine construct demonstrated structural stability, thermostability, solubility, and hydrophilicity. The vaccine produced 250 B-memory cells per mm3 and approximately 16,000 IgM + IgG counts, indicating an effective immune response against A. xylosoxidans. Moreover, the vaccine candidate interacted stably with toll-like receptor 5, a pattern recognition receptor, with a confidence score of 0.98. These results highlight the potency of the designed vaccine candidate, suggesting its potential to withstand rigorous in vitro and in vivo clinical trials. This epitope-based vaccine could serve as the first preventive immunotherapy against A. xylosoxidans infections, addressing this bacterium's health and financial burdens. The findings demonstrate the value of employing immunoinformatic tools in vaccine development, paving the way for more precise and tailored approaches to combating microbial threats.

Retrospective case-control study on the outcomes of early minimally invasive pleural lavage for pleural empyema in oncology patients

BACKGROUND

Oncology patients carry a substantial risk of developing pleural empyema. Here, we report the preliminary results of our early video-assisted thoracoscopic surgery (VATS) lavage strategy in cases of empyema occurring in patients undergoing (radio-) chemotherapy.

METHODS

This was a retrospective case-control study comparing early VATS lavage (test group, current therapy since January 2018, n = 46) versus VATS pleurectomy (historical control; before January 2018, n = 46).

RESULTS

Five patients in the control group and one in the test group developed recurrence of empyema within 30 days. Complications were more severe and more frequently observed in the historical control group than in the test group (30/46 vs. 12/46 CI: 5%-95%, p = < 0.05). Early VATS lavage saved operating time, allowed a shorter ICU stay (2.6 days CI: 5%-95% vs. 5.1 days CI: 5%-95%, p = ns) and an earlier hospital discharge (6.1 days CI: 5%-95% vs. 13.5 days CI: 5%-95%, p < 0.05). Moreover, radio and/or chemotherapy could be reinitiated earlier (15 ± 20.5 days CI: 5%-95% vs. 40 ± 12 days CI: 5%-95%, p < 0.05).

CONCLUSIONS

In this retrospective cohort study, early VATS lavage was found to have a beneficial effect especially on hospital stay and enabling an earlier restart of radio- and/or chemotherapy.

Predictors and Clinical Outcomes in Empyema Thoracis Patients Presenting to the Emergency Department Undergoing Video-Assisted Thoracoscopic Surgery

Background: Video-assisted thoracoscopic surgery (VATS) is widely used for the treatment of empyema. We evaluated clinical symptoms, laboratory examinations, and thoracentesis to assess patients in the emergency department (ED) with empyema thoracis, undergoing VATS to identify predictors of adverse outcomes. Methods: This retrospective study was conducted by reviewing records of ED patients with pleural empyema admitted for VATS from January 2007 to June 2014. Demographic data, clinical symptoms, and laboratory examinations were compared for survivors (Group I) and non-survivors (Group II). Logistic regression analysis was used to identify parameters related to postoperative mortality. Results: From 380 patients, 7.6% (n = 29) died postoperatively. Survivors and non-survivors exhibited differences in age, gender, presence of cough, dyspnea, chest pain, empyema stage, cerebrovascular disease, malignancy, the glucose level of pleural fluid, serum hemoglobin, platelet count, blood urea nitrogen, and potassium levels. The logistic analysis demonstrated that the most significant factor related to the postoperative morbidity is chest pain (p = 0.018). Conclusions: VATS could be a safe option for pediatric and geriatric patients. Age does not appear to affect postoperative mortality. A high degree of awareness is essential for perioperative management and early surgical treatment when ED patients present with the clinical symptom of chest pain.

The microbiology of pleural infection in adults: a systematic review

BACKGROUND AND OBJECTIVES

Pleural infection is a major cause of morbidity and mortality among adults. Identification of the offending organism is key to appropriate antimicrobial therapy. It is not known whether the microbiological pattern of pleural infection is variable temporally or geographically. This systematic review aimed to investigate available literature to understand the worldwide pattern of microbiology and the factors that might affect such pattern.

DATA SOURCES AND ELIGIBILITY CRITERIA

Ovid MEDLINE and Embase were searched between 2000 and 2018 for publications that reported on the microbiology of pleural infection in adults. Both observational and interventional studies were included. Studies were excluded if the main focus of the report was paediatric population, tuberculous empyema or post-operative empyema.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies of ≥20 patients with clear reporting of microbial isolates were included. The numbers of isolates of each specific organism/group were collated from the included studies. Besides the overall presentation of data, subgroup analyses by geographical distribution, infection setting (community versus hospital) and time of the report were performed.

RESULTS

From 20 980 reports returned by the initial search, 75 articles reporting on 10 241 patients were included in the data synthesis. The most common organism reported worldwide was Staphylococcus aureus. Geographically, pneumococci and viridans streptococci were the most commonly reported isolates from tropical and temperate regions, respectively. The microbiological pattern was considerably different between community- and hospital-acquired infections, where more Gram-negative and drug-resistant isolates were reported in the hospital-acquired infections. The main limitations of this systematic review were the heterogeneity in the method of reporting of certain bacteria and the predominance of reports from Europe and South East Asia.

CONCLUSIONS

In pleural infection, the geographical location and the setting of infection have considerable bearing on the expected causative organisms. This should be reflected in the choice of empirical antimicrobial treatment.

Clinical Outcome and Risk Factors for Emergency Department Adult Patients with Thoracic Empyema after Video-Assisted Thoracic Surgical Procedure

Background: Empyema is a purulent infection of the pleural cavity that is most relevant to parapneumonia effusion. Video-assisted thoracoscopic surgery (VATS) is an option for stage 2 (fibrinopurulent) and stage 3 (organizational). Surgeons may see critically ill patients with pleural empyema who present to the emergency department (ED). The purpose of this work is to investigate the outcomes of ED adult patients with thoracic empyema undergoing a thoracoscopic surgical procedure and to identify possible risk factors for death. Methods: We reviewed retrospectively the clinical characteristics and treatment outcomes of patients with thoracic empyema who received this diagnosis at our center from January 2012 to June 2014. Patients <20 years old were excluded from this study. The prognostic values of age, sex, comorbidities, clinical presentations, location, stage, and laboratory examinations were evaluated. Uni-variable analysis and multi-variable modeling were performed to determine significant risk factors for post-operative death. Results: Seventeen of 160 patients died post-operatively. Two groups (survivors and non-survivors) significantly differed in age (p = 0.013), sex (p = 0.026), comorbidity (p = 0.017), cough (p = 0.024), chest pain (p = 0.016), serum hemoglobin (p = 0.001), and potassium (p = 0.004) levels. Further logistic regression analysis showed statistically significant differences in age, hemoglobin levels, and potassium levels. Conclusion: Among the ED patients with thoracic empyema, older age, lower hemoglobin levels, and higher potassium levels are associated with post-operative death after VATS. These findings underline the importance of careful peri-operative treatment in older patients with signs of empyema when they present to the ED.

Achromobacter xylosoxidans/denitrificans bacteremia and subsequent fatal Escherichia coli/Streptococcus anginosus pleural empyema

Achromobacter xylosoxidans, a gram-negative bacillus with low virulence has rarely been reported to cause clinically significant infections. We report an unusual case of MDR Achromobacter xylosoxidans/denitrificans bacteremia from a peripherally inserted central catheter (PICC) and subsequent fatal pleural empyema due to MDR Escherichia coli and Streptococcus anginosus. A 44-year-old male presented to the hospital with chief complaints of chest tightness associated with a productive cough. He was found to have pleural empyema secondary to MDR E. coli and S. anginous. Three months prior to current presentation, he had a history of MDR A. xylosoxidans originating from a PICC. The patient expired even after appropriate management. Thoracic empyema continues to cause significant morbidity and mortality despite the improvement of antimicrobial therapy and the existence of multiple options for drainage of the infected pleural space. The bacteriology of thoracic empyema has been changing since the introduction of antibiotics. Typical antibiotics used to treat these MDR pathogens have become obsolete. Therefore, physicians should be aggressive in their diagnostic approach to pleural empyema, since the isolation of MDR aerobic gram-negative bacilli or multiple pathogens from the pleural fluid is associated with a poor prognosis and indicates a need for more aggressive antimicrobial chemotherapy. Also, the association of indwelling medical devices and MDR Achromobacter bacteremia should be known.

Population-based cohort study investigating the correlation of diabetes mellitus with pleural empyema in adults in Taiwan

We assessed the association between diabetes mellitus and the risk of pleural empyema in Taiwan.A population-based retrospective cohort study was conducted using the database of the Taiwan National Health Insurance Program. There were 28,802 subjects aged 20 to 84 years who were newly diagnosed with diabetes mellitus from 2000 to 2010 as the diabetes group and 114,916 randomly selected subjects without diabetes mellitus as the non-diabetes group. The diabetes group and the non-diabetes group were matched by sex, age, comorbidities, and the year of index date. The incidence of pleural empyema at the end of 2011 was estimated. A multivariable Cox proportional hazards regression model was used to estimate the hazard ratio (HR) and 95% confidence interval (95% CI) for pleural empyema associated with diabetes mellitus.The overall incidence of pleural empyema was 1.65-fold higher in the diabetes group than that in the non-diabetes group (1.58 vs 0.96 per 10,000 person-years, 95% CI 1.57-1.72). After adjusting for confounders, a multivariable Cox proportional hazards regression model revealed that the adjusted HR of pleural empyema was 1.71 in subjects with diabetes mellitus (95% CI 1.16-2.51), compared with those without diabetes mellitus. In further analysis, even in the absence of any comorbidity, the adjusted HR was 1.99 for subjects with diabetes mellitus alone (95% CI 1.18-3.38).Diabetic patients confer a 1.71-fold increased hazard of developing pleural empyema. Even in the absence of any comorbidity, the risk remains existent.

Acute thoracic empyema: clinical characteristics and outcome analysis of video-assisted thoracoscopic surgery

BACKGROUND/PURPOSE

Acute thoracic empyema is a common clinical problem worldwide, resulting in substantial morbidity and mortality. The objective of this study was to report its clinical characteristics and to evaluate whether thoracoscopic surgery is associated with a lower rate of in-hospital mortality compared with nonoperative drainage.

METHODS

Between 2001 and 2010, we retrospectively reviewed the clinical characteristics, bacteriological studies, and treatment outcomes of 602 patients with acute thoracic empyema. Thoracoscopic surgery was performed in 417 (69.2%) patients, while the remaining patients underwent nonoperative drainage. After treatment, 77 patients (12.8%) died in the hospital. A propensity score-based process, matched on potential risk factors for in-hospital mortality, was performed to select patients with equalized potential prognostic factors in the thoracoscopy and nonoperative groups. The log-rank test was used to compare the survival time with discharge between the two matched groups.

RESULTS

Multivariate analysis showed that age, malignancy, chronic lung disease, chronic renal insufficiency, liver cirrhosis, polymicrobial infection, and positive bacterial culture were risk factors for in-hospital mortality. The propensity score-matched analysis showed that the in-hospital mortality difference was significant (p = 0.014) and the Kaplan-Meier survival analysis revealed a higher survival rate to discharge (p < 0.001 by log-rank test), both favoring thoracoscopy over nonoperative drainage.

CONCLUSION

Acute thoracic empyema carries a high mortality rate, especially in elderly patients with coexisting medical conditions and polymicrobial and positive bacterial cultures. Our study results also showed that thoracoscopy is feasible and might provide better chances for survival in borderline operable patients than nonoperative drainage.

Enteral tube feeding alters the oral indigenous microbiota in elderly adults

Enteral tube feeding is widely used to maintain nutrition for elderly adults with eating difficulties, but its long-term use alters the environment of the oral ecosystem. This study characterized the tongue microbiota of tube-fed elderly adults by analyzing the 16S rRNA gene. The terminal restriction fragment length polymorphism (T-RFLP) profiles of 44 tube-fed subjects were compared with those of 54 subjects fed orally (average age, 86.4 ± 6.9 years). Bar-coded pyrosequencing data were also obtained for a subset of the subjects from each group (15 tube-fed subjects and 16 subjects fed orally). The T-RFLP profiles demonstrated that the microbiota of the tube-fed subjects was distinct from that of the subjects fed orally (permutational multivariate analysis of variance [perMANOVA], P < 0.001). The pyrosequencing data revealed that 22 bacterial genera, including Corynebacterium, Peptostreptococcus, and Fusobacterium, were significantly more predominant in tube-fed subjects, whereas the dominant genera in the subjects fed orally, such as Streptococcus and Veillonella, were present in much lower proportions. Opportunistic pathogens rarely detected in the normal oral microbiota, such as Corynebacterium striatum and Streptococcus agalactiae, were often found in high proportions in tube-fed subjects. The oral indigenous microbiota is disrupted by the use of enteral feeding, allowing health-threatening bacteria to thrive.

Clinical and microbiological characteristics of community-acquired thoracic empyema or complicated parapneumonic effusion caused by Klebsiella pneumoniae in Taiwan

Klebsiella pneumoniae is the major cause of community-acquired pyogenic infections in Taiwan and is becoming an increasing problem in acute thoracic empyema. This study evaluated the clinical and microbiological characteristics of community-acquired thoracic empyema or complicated parapneumonic effusion caused by K. pneumoniae in Taiwanese adults treated during the period 2001-2008 at a tertiary medical center. All clinical isolates were examined for capsular serotypes K1/K2, and pulsed-field gel electrophoresis (PFGE) was performed on strains of the same serotype. K. pneumoniae was the most frequent cause of community-acquired thoracic empyema or complicated parapneumonic effusion. It was associated with high mortality (32.4%) and was an independent risk factor for fatal outcome. Diabetes mellitus, liver cirrhosis, and bronchogenic carcinoma were independent risk factors for K. pneumoniae infection. Serotypes K1 (9/37, 24.3%) and K2 (13/37, 35.1%) were the prevalent strains but did not predispose patients to poor outcome compared with other non-K1/K2 serotypes. There was no major cluster of isolates found among serotype K1/K2 strains. In summary, physicians should be aware of the risk factors for thoracic empyema or complicated parapneumonic effusion caused by K. pneumoniae and the associated high mortality, and monitor these patients more closely.

Benign thoracic disease in the elderly

The spectrum of benign thoracic disease in the elderly includes structural abnormalities, infectious disease and their complications, benign neoplastic growths, and autoimmune disease. Differences in physiologic reserve in this population make diagnosis difficult, as elderly patients may not present in the classic fashion, as well as complicate treatment. Benign thoracic disease in the elderly can pose a challenging clinical problem. Older patients with comorbid diseases may have poor tolerance of unnecessary surgical interventions. However, benign disorders of the chest associated with symptoms attributable to effusion or obstruction of airways can limit quality of life. Minimally invasive techniques (eg, video-assisted thoracoscopic surgery) can limit the morbidity associated with intervention. Additionally, prompt intervention may spare the patient more invasive treatments. For example, early effusions can be managed with simple drainage rather than thoracotomy and decortication. With respect to suspected benign thoracic lesions in the elderly, guiding principles for management include avoiding unnecessary interventions while not overlooking potential malignancies. Close surveillance of progressive symptoms, ensuring no radiographic change in the size of the lesion over 2 years, and use of positron-emission tomography remain the diagnostic keys to accurate management.

Interventional management of pleural infections

Pleural infections represent an important group of disorders that is characterized by the invasion of pathogens into the pleural space and the potential for rapid progression to frank empyema. Previous epidemiologic studies have indicated that empyema is increasing in prevalence, which underscores the importance of urgent diagnosis and effective drainage to improve clinical outcomes. Unfortunately, limited evidence exists to guide clinicians in selecting the ideal drainage intervention for a specific patient because of the broad variation that exists in the intrapleural extent of infection, presence of locules, comorbid features, respiratory status, and virulence of the underlying pathogen. Moreover, many patients experience delays in both the recognition of infected pleural fluid and the initiation of appropriate measures to drain the pleural space. The present review provides an update on the pathogenesis and interventional therapy of pleural infections with an emphasis on the unique role of image-guided drainage with small-bore catheters.

Hospital-acquired thoracic empyema in adults: a 5-year study

BACKGROUND

The objective of this study was to assess the etiology, microbiology and outcome of hospital-acquired thoracic empyema (HATE) in adults.

METHODS

From December 2001 to December 2006, 459 adult patients with a diagnosis of thoracic empyema in a tertiary hospital were screened for HATE. HATE was defined as a new pleural empyema which developed after 48 hours of hospitalization.

RESULTS

In total, 56 adult (>or=18 years) patients who were diagnosed with HATE were enrolled in our series, including 35 men (62.5%) and 21 women (37.5%), with ages ranging from 22 to 87 years old (mean = 59). Causes of HATE were classified into two categories: hospital-acquired pneumonia (HAP) related (n = 25) and non-HAP related (n = 31). Causes of non-HAP related empyema were comprised of catheter-related infections (n = 20), hepatobiliary tract infections (n = 6), septic emboli (n = 4), and postpneumonectomy (n = 1). Comparing the bacteriology between the two categories, HAP-related empyema had a significantly higher incidence of aerobic Gram-negative organisms (76% vs. 38.7%, P = 0.005), polymicrobial pathogens (40% vs. 9.7%, P = 0.008), and anaerobic pathogens (20% vs. 0%, P = 0.009) than non-HAP related empyema. However, there was no significant difference in mortality rate (60% vs. 52%, P = 0.52) between the two categories.

CONCLUSIONS

Choice of antibiotic treatment for HATE should be based on the etiology of the pleural infection. In treating HAP-related empyema, antibiotics should cover aerobic Gram-negative, polymicrobial, and anaerobic pathogens.

A comparative study of community- and nursing home-acquired empyema thoracis

OBJECTIVES

To compare the clinical presentation, microbiological features, and outcomes of patients with community-acquired empyema (CAE) with those of patients with nursing home-acquired empyema (NHAE).

DESIGN

A retrospective observational study.

SETTING

Three tertiary care centers.

PARTICIPANTS

One hundred fourteen patients admitted from the community and 55 patients transferred from nursing homes.

MEASUREMENTS

Baseline sociodemographic information, activities of daily living, Charlson Comorbidity Index score, and clinica, and microbiologic data were obtained. Outcome was assessed at hospital discharge and 6 months postdischarge.

RESULTS

Patients admitted from nursing homes had a delayed presentation, with dyspnea, weight loss, and anemia as the predominant manifestation. Patients with CAE presented more acutely, with fever, cough, and chest pain. Anaerobic organisms were more commonly isolated from patients with NHAE. The success rate of nonsurgical intervention was significantly lower for the NHAE patients than for the CAE group (39% vs 63; P=.01). In-hospital mortality was not significantly different between the two groups (NHAE, 18%; CAE, 8%; P=.09). In a Cox regression analysis, preadmission functional status (hazard ratio (HR)=1.26, 95% confidence interval (CI)=1.19-1.4; P<.001) and surgical intervention (HR=0.47, 95% CI=0.24-0.92; P=.03) were the only variables highly correlated with long-term outcome.

CONCLUSION

Patients admitted with NHAE have distinctly different clinical and microbiological presentation from that of patients with CAE. Because of the delayed presentation in patients with NHAE, medical treatment alone may be associated with higher rate of failure. Surgical therapy should be considered for selected cases, with the aim of improving long-term survival.