Sputum bacteriology in hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease in Taiwan with an emphasis on Klebsiella pneumoniae and Pseudomonas aeruginosa

Accelerated Lung Function Decline and Mucus-Microbe Evolution in Chronic Obstructive Pulmonary Disease

Rationale: Progressive lung function loss is recognized in chronic obstructive pulmonary disease (COPD); however, no study concurrently evaluates how accelerated lung function decline relates to mucus properties and the microbiome in COPD. Objectives: Longitudinal assessment of mucus and microbiome changes accompanying accelerated lung function decline in patients COPD. Methods: This was a prospective, longitudinal assessment of the London COPD cohort exhibiting the greatest FEV1 decline (n = 30; accelerated decline; 156 ml/yr FEV1 loss) and with no FEV1 decline (n = 28; nondecline; 49 ml/yr FEV1 gain) over time. Lung microbiomes from paired sputum (total 116 specimens) were assessed by shotgun metagenomics and corresponding mucus profiles evaluated for biochemical and biophysical properties. Measurements and Main Results: Biochemical and biophysical mucus properties are significantly altered in the accelerated decline group. Unsupervised principal component analysis showed clear separation, with mucus biochemistry associated with accelerated decline, whereas biophysical mucus characteristics contributed to interindividual variability. When mucus and microbes are considered together, an accelerated decline mucus-microbiome association emerges, characterized by increased mucin (MUC5AC [mucin 5AC] and MUC5B [mucin 5B]) concentration and the presence of Achromobacter and Klebsiella. As COPD progresses, mucus-microbiome shifts occur, initially characterized by low mucin concentration and transition from viscous to elastic dominance accompanied by the commensals Veillonella, Gemella, Rothia, and Prevotella (Global Initiative for Chronic Obstructive Lung Disease [GOLD] A and B) before transition to increased mucus viscosity, mucins, and DNA concentration together with the emergence of pathogenic microorganisms including Haemophilus, Moraxella, and Pseudomonas (GOLD E). Conclusions: Mucus-microbiome associations evolve over time with accelerated lung function decline, symptom progression, and exacerbations affording fresh therapeutic opportunities for early intervention.

Spectrum and antimicrobial resistance in acute exacerbation of chronic obstructive pulmonary disease with pneumonia: a cross-sectional prospective study from Vietnam

BACKGROUND

Respiratory infections have long been recognized as a primary cause of acute exacerbation of chronic obstructive pulmonary disease (AE-COPD). Additionally, the emergence of antimicrobial resistance has led to an urgent and critical situation in developing countries, including Vietnam. This study aimed to investigate the distribution and antimicrobial resistance of bacteria in patients with AE-COPD using both conventional culture and multiplex real-time PCR. Additionally, associations between clinical characteristics and indicators of pneumonia in these patients were examined.

METHODS

This cross-sectional prospective study included 92 AE-COPD patients with pneumonia and 46 without pneumonia. Sputum specimens were cultured and examined for bacterial identification, and antimicrobial susceptibility was determined for each isolate. Multiplex real-time PCR was also performed to detect ten bacteria and seven viruses.

RESULTS

The detection rates of pathogens in AE-COPD patients with pneumonia were 92.39%, compared to 86.96% in those without pneumonia. A total of 26 pathogenic species were identified, showing no significant difference in distribution between the two groups. The predominant bacteria included Klebsiella pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae, followed by Acinetobacter baumannii and Streptococcus mitis. There was a slight difference in antibiotic resistance between bacteria isolated from two groups. The frequency of H. influenzae was notably greater in AE-COPD patients who experienced respiratory failure (21.92%) than in those who did not (9.23%). S. pneumoniae was more common in patients with stage I (44.44%) or IV (36.36%) COPD than in patients with stage II (17.39%) or III (9.72%) disease. ROC curve analysis revealed that C-reactive protein (CRP) levels could distinguish patients with AE-COPD with and without pneumonia (AUC = 0.78).

CONCLUSION

Gram-negative bacteria still play a key role in the etiology of AE-COPD patients, regardless of the presence of pneumonia. This study provides updated evidence for the epidemiology of AE-COPD pathogens and the appropriate selection of antimicrobial agents in Vietnam.

Exploring the impact of OSA on short-term survival in patients with AECOPD admitted to the ICU

BACKGROUND

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is characterized by a sudden worsening of chronic obstructive pulmonary disease (COPD) symptoms, which significantly contributes to hospitalizations related to COPD symptoms. Previous research has mainly focused on the correlation between obstructive sleep apnea (OSA) and COPD. However, there were few studies that investigated the short-term mortality rate of AECOPD patients with or without OSA.

METHODS

Data for our research was taken from the Medical Information Mart for Intensive Care Database IV. A total of 1332 patients were included in the study based on well-defined criteria for selection and exclusion. By analyzing the characteristics of AECOPD patients, we compared those with and without OSA.

RESULTS

There were 1122 AECOPD patients without OSA, 210 patients with OSA. In comparison to those without OSA, patients with OSA exhibited lower 30-day and 90-day ICU mortality with unadjusted HR, as well as lower hospital mortality with unadjusted OR. However, after adjustments were made, there were no significant associations observed between OSA and short-term mortality, including 30-day ICU mortality, 90-day ICU mortality, ICU mortality, and hospital mortality in AECOPD patients. Subgroup analysis revealed that OSA may act as a risk factor for AECOPD patients with a BMI lower than 30 kg/m2.

CONCLUSIONS

There is no impact on short-term survival in AECOPD patients with OSA under intensive care unit (ICU) management and nursing.

Chronic obstructive pulmonary disease and the airway microbiome: A review for clinicians

Chronic obstructive pulmonary disease (COPD) is a complex heterogeneous disease characterized by progressive airflow limitation and chronic inflammation. The progressive development and long-term repeated acute exacerbation of COPD make many patients still unable to control the deterioration of the disease after active treatment, and even eventually lead to death. An increasing number of studies have shown that the occurrence and development of COPD are closely related to the composition and changes of airway microbiome. This article reviews the interaction between COPD and airway microbiome, the potential mechanisms of interaction, and the treatment methods related to microbiome. We elaborated the internal correlation between airway microbiome and different stages of COPD, inflammatory endotypes, glucocorticoid and antibiotic treatment, analyze the pathophysiological mechanisms such as the "vicious cycle" hypothesis, abnormal inflammation-immune response of the host and the "natural selection" of COPD to airway microbiome, introduce the treatment of COPD related to microbiome and emphasize the predictive value of airway microbiome for the progression, exacerbation and prognosis of COPD, as well as the guiding role for clinical management of patients, in order to provide a new perspective for exploring the pathogenesis of COPD, and also provide clues and guidance for finding new treatment targets.

Acute Exacerbation of Chronic Obstructive Pulmonary Disease Due to Carbapenem-Resistant Klebsiella pneumoniae-Induced Pneumonia: Clinical Features and Prognostic Factors

Purpose

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is closely related to respiratory tract infection. The aim of this study was to investigate the clinical features and prognostic factors of CRKP-induced pneumonia in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients.

Methods

A single-centre, retrospective case-control study on COPD patients hospitalized for acute exacerbation and CRKP-induced pneumonia was conducted from January 1, 2016, to December 31, 2022. The mortality rate of acute exacerbation due to CRKP-induced pneumonia was investigated. The patients were divided into the CRKP-induced pneumonic acute exacerbation (CRKPpAE) group and the non-CRKP-induced pneumonic acute exacerbation (non-CRKPpAE) group, and the clinical characteristics and prognostic factors were compared using univariate analysis and multivariate analysis.

Results

A total of 65 AECOPD patients were included, composed of 26 patients with CRKPpAE and 39 patients with non-CRKPpAE. The mortality rate of CRKPpAE was 57.69%, while non-CRKPpAE was 7.69%. Compared with non-CRKPpAE, a history of acute exacerbation in the last year (OR=8.860, 95% CI: 1.360-57.722, p=0.023), ICU admission (OR=11.736, 95% CI: 2.112-65.207, p=0.005), higher NLR levels (OR=1.187, 95% CI: 1.037-1.359, p=0.013) and higher D-dimer levels (OR=1.385, 95% CI: 1.006-1.905, p=0.046) were independently related with CRKPpAE. CRKP isolates were all MDR strains (26/26, 100%), and MDR strains were also observed in non-CRKP isolates (5/39, 12.82%).

Conclusion

Compared with non-CRKPpAE, CRKPpAE affects the COPD patient's condition more seriously and significantly increases the risk of death.

A Systematic Review of the Pulmonary Microbiome in Patients with Acute Exacerbation COPD Requiring ICU Admission

Background: Chronic obstructive pulmonary disease (COPD) is a major health concern. Acute exacerbations (AECOPD) may require intensive care unit (ICU) admission and mechanical ventilation. Acute infections and chronic colonization of the respiratory system are known to precipitate AECOPD. Detailed knowledge of the respiratory microbiome could lead to effective treatment and prevention of exacerbations. Objective: The aim of this review is to summarize the available evidence on the respiratory microbiome of patients with a severe AECOPD requiring mechanical ventilation and intensive care admission. Methods: A systematic literature search was conducted to identify the published papers until January 2023. The collected data were then subjected to qualitative analysis. After the first analysis, a secondary focused review of the most recent publications studying the relationship between microbiome and mortality in AECOPD was performed. Results: Out of 120 screened articles six articles were included in this review. Potentially pathogenic microorganisms (PPMs) were identified in 30% to 72% of the patients with community-acquired bacteria, gram-negative enteric bacilli, Stenotrophomonas and Pseudomonas being the most frequently isolated. During hospitalization, 21% of patients experienced colonization by PPMs. Adequate antimicrobial therapy resulted in the eradication of 77% of the identified PPMs. However, 24% of the bacteria displayed multi-drug resistance leading to prolonged or failure of eradication. Conclusion: PPMs are prevalent in a significant proportion of patients experiencing an AECOPD. The most identified PPMs include community-acquired pathogens and gram-negative enteric bacilli. Notably, no differences in mortality or duration of ventilation were observed between patients with and without isolated PPMs. However, the included studies did not investigate the virome of the patients, which may influence the microbiome and the outcome of infection. Therefore, further research is essential to comprehensively investigate the complete microbial and viral composition of the lower respiratory system in COPD patients admitted to the ICU.

Sputum culture and antibiotic resistance in elderly inpatients with exacerbation of chronic obstructive pulmonary disease at a tertiary geriatric hospital in southern Vietnam

OBJECTIVE

To determine the rate of positive culture sputum and related factors as well as the microorganism features and antibiotic susceptibility of pathogens in elderly inpatients with exacerbation of chronic obstructive pulmonary disease (COPD) in Thong Nhat Hospital, Vietnam.

METHODS

This cross-sectional study included elderly patients admitted to the hospital because of exacerbation of COPD. Data of their medical history, symptoms and signs were collected, and the patients were instructed to collect sputum sample. A positive culture was identified with the growth of ≥ 10⁵ colony-forming units per milliliter. Antibiotic susceptibility testing was performed according to the European Committee on Antimicrobial Susceptibility Testing.

RESULTS

There were 167 participants (mean age: 77.5 ± 8.8 years, 87.4% male). The culture-positive rate was 25.1%. A higher proportion of positive culture was among participants with purulent sputum (p = 0.029) and with severe and very severe airflow obstruction (p = 0.005). Three most common agents were Acinetobacter baumannii (24.4%), Klebsiella pneumoniae (22.2%), and Pseudomonas aeruginosa (15.6%). Despite high resistance to almost other antibiotics (> 50% resistance), Acinetobacter baumannii and Pseudomonas aeruginosa were sensitive to colistin, tobramycin, and gentamicin (> 80% susceptibility). Klebsiella pneumoniae was highly sensitive to almost common antibiotics (> 80% susceptibility). Among Gram-positive pathogens, methicillin-resistant Staphylococcus aureus (MRSA) was completely sensitive to vancomycin, teicoplanin, and linezolid.

CONCLUSION

The sputum culture-positive rate in this study was not high. Most prevalent isolated pathogens were Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Acinetobacter baumannii and Pseudomonas aeruginosa were sensitive to tobramycin, gentamicin, and colistin. Commonly used antibiotics remained effective against Klebsiella pneumoniae. MRSA was sensitive to vancomycin, teicoplanin, and linezolid.

Update on guidelines for the treatment of COPD in Taiwan using evidence and GRADE system-based recommendations

Chronic obstructive pulmonary disease (COPD) has significant contributions to morbidity and mortality world-wide. Early symptoms of COPD are not readily distinguishable, resulting in a low rate of diagnosis and intervention. Different guidelines and recommendatations for the diagnosis and treatment of COPD exist globally. The first edition of clinical practice guidelines for COPD was published in 2016 by the Ministry of Health and Welfare in Taiwan in collaboration with the Taiwan evidence-based medicine association and Cochrane Taiwan, and was revised in 2019 in order to update recent diagnostic and therapeutic modalities for COPD and its acute exacerbation. This revised guideline covered a range of topics highlighted in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) report, including strategies for the diagnosis, assessment, monitoring, and management of stable COPD and exacerbations, with particular focus on evidence from Taiwan. The recommendations included in the revised guideline were formed based on a comprehensive systematic review or meta-analysis of specific clinical issues identified by an expert panel that surveyed relevant scientific evidence in the literature and guidelines published by the clinical communities and organizations nationally and internationally. The guidelines and recommendations are applicable to the clinical settings in Taiwan. We expect this revised guideline to facilitate the diagnosis, treatment and management of patients with COPD by physicians and health care professionals in Taiwan. Adaptations of the materials included herein for educational and training purposes is encouraged.

Microbiota of Bronchoalveolar Lavage Samples from Patients of Lower Respiratory Tract Infection – A Changing Trend

Bronchoalveolar lavage (BAL) is the saline wash of the bronchial tree, which aids in diagnosing various pulmonary pathologies. The present study was contemplated with an aim to know the clinical, microbiological profile of BAL samples along with its sensitivity pattern and to assess its utility as a diagnostic tool. This was a prospective observational study, carried over 90 patients presenting with lower respiratory tract infections. The total microbial recovery rate from BAL was 39 (43.3%). The sensitivity, specificity and positive predictive value of BAL were found to be 76.4%, 89.7% and 90.6% respectively. Maximum isolates were bacteria (25.5%) followed by Mycobacterium tuberculosis (MTB) (16.6%) and fungi (1.1%). Predominant bacterial isolates were Gram-negative (81.5%) compared to Gram-positive (18.5%). Multidrug resistance (MDR) in bacteria was seen in 59.2% of isolates. BAL is a valuable diagnostic tool to find not only bacterial but mycobacterial and fungal infections in patients with lower respiratory tract infection (LRTI). A trend towards LRTI with Gram-negative infections is on the rise and they tend to be multidrug-resistant. Hence checking susceptibility patterns is crucial to start evidence-based treatment.

Lower Respiratory Tract Pathogens and Their Antimicrobial Susceptibility Pattern: A 5-Year Study

Lower respiratory tract infections (LRTIs) are the most common infections in humans. It is estimated that 2.74 million deaths worldwide occur each year due to LRTIs. The aim of the study was to determine the frequency and antibiotic susceptibility pattern of microorganisms isolated from respiratory samples of patients with LRTIs. Between January 2015 and December 2019, a total of 7038 sputum and bronchoaspirate samples from suspected LRTI patients were collected. Among them, 2753 samples (39.1%) showed significant microbial growth on culture media. The LRTI rate was higher in patients with male gender (67.1%) and with age between 40–59 years (48.6%). The microorganism identification and antibiotic susceptibility testing were performed with Vitek 2. Out of 4278 isolates species, 3102 (72.5%) were Gram-negative bacteria, 1048 (24.5%) were Gram-positive bacteria, and 128 (3.0%) were Candida spp. Major microorganisms isolated were Acinetobacter baumannii (18.6%), Staphylococcus aureus (15.2%), Pseudomonas aeruginosa (14.2%), and Klebsiella pneumoniae (10.9%). In antimicrobial susceptibility testing, Staphylococcus aureus isolates were mostly resistant to Penicillin G (84.1%) and Oxacillin (48.1%), whereas they demonstrated maximum sensitivity to Tigecycline (100%) and Linezolid (99.5%). Among Gram-negative isolates, Acinetobacter baumannii showed maximum sensitivity to Colistin but was resistant to other antibiotics (95–99%). Klebsiella pneumoniae isolates were mostly resistant to Cefotaxime (72.7%) and sensitive to Gentamicin (54.3%), and Pseudomonas aeruginosa was resistant to Ciprofloxacin (40.3%) and sensitive to Amikacin (85.9%). Gram-negative bacteria represented the species most commonly isolated. A high rate of antimicrobial resistance was observed in this study. In conclusion, the correct identification of causative microorganisms and their susceptibility patterns to antibiotics is crucial for choosing targeted and effective antibiotic therapy in LRTIs, and to prevent the emergence of multidrug-resistant bacteria.

The role of infectious pathogens in exacerbation of chronic obstructive pulmonary disease in Dakahlia Governorate

Background

Exacerbations of chronic obstructive pulmonary disease (COPD) represent important events in the management of COPD because of its negative impact on health status and disease progression. The etiology of acute exacerbations of chronic obstructive pulmonary disease (COPDAE) is heterogeneous and still under discussion. So, this study was planned to investigate the role of infectious pathogens (fungi and atypical mycobacteria in addition to the well-known bacteria) in patients with COPD exacerbation in our locality.

Results

This observational cross-sectional study was conducted on 100 patients with acute exacerbation of COPD. Sputum specimens were collected for mycobacterial and fungal examination in addition to routine sputum bacteriology. All sputum samples were negative for typical and atypical mycobacteria whereas sputum samples of 18 patients (18%) were negative for fungi. Mixed fungal growth was found in 19 patients (19%).Candidawas isolated from 67 patients (67%),Aspergilluswas isolated from 27 patients (27%),Alternariawas isolated from 3 patients (3%), and other fungi were isolated from 4 patients (4%). As regards sputum bacteriology, sputum samples of 49 patients (49%) have bacterial growth.Streptococcus pneumoniaewas isolated from 16 samples (16%) and represents the most frequent bacterial isolate in this study.

Conclusion

The present study indicates that typical and atypical mycobacteria have no role in COPD exacerbations in our locality. However, fungi and bacteria may have a role in COPD exacerbations.

Predictors of Severity and Co-Infection Resistance Profile in COVID-19 Patients: First Report from Upper Egypt

BACKGROUND

The emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted in a worldwide devastating effect with a diagnostic challenge. Identifying risk factors of severity aids in assessment for the need of early hospitalization. We aimed to demonstrate, for the first time, the clinical, laboratory and radiological characteristics of coronavirus disease 2019 (COVID-19) patients, to identify the predictors of severity and to describe the antimicrobial resistance profile in patients from Upper Egypt.

MATERIALS AND METHODS

Demographic characters, clinical presentations, laboratory, and radiological data were recorded and analyzed. Presence of other respiratory microorganisms and their sensitivity patterns were identified using the VITEK2 system. Resistance-associated genes were tested by PCR.

RESULTS

The study included 260 COVID-19 patients. The majority were males (55.4%) aged between 51 and 70 years. Hypertension, diabetes, and ischemic heart disease were common comorbidities. Main clinical manifestations were fever (63.8%), cough (57.7%), dyspnea (40%) and fatigue (30%). According to severity, 51.5% were moderate, 25.4% mild and 23% severe/critical. Lymphopenia, elevated CRP, ferritin, and D-dimer occurred in all patients with significantly higher value in the severe group. Age >53 years and elevated ferritin ≥484 ng/mL were significant risk factors for severity. About 10.7% of the COVID-19 patients showed bacterial and/or fungal infections. Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were the predominant isolated bacteria while Candida albicans and Candida glabrata were the predominant isolated fungi. All Staphylococci were methicillin-resistant and carried the mecA gene. Gram-negative isolates were multidrug-resistant and carried different resistance-associated genes, including NDM-1, KPC, TEM, CTX-M, and SHV.

CONCLUSION

Older age and elevated serum ferritin were significant risk factors for severe COVID-19. Bacterial co-infection and multidrug resistance among patients with COVID-19 in Upper Egypt is common. Testing for presence of other co-infecting agents should be considered, and prompt treatment should be carried out according to the antimicrobial sensitivity reports.

Impact of Pseudomonas aeruginosa Isolation on Mortality and Outcomes in an Outpatient Chronic Obstructive Pulmonary Disease Cohort

BACKGROUND

Tracheobronchial colonization by Pseudomonas aeruginosa (PA) has been shown to negatively impact outcomes in cystic fibrosis and bronchiectasis. There is uncertainty whether the same association is prevalent in chronic obstructive pulmonary disease (COPD), especially in the outpatient setting. Our objective was to determine (1) whether PA isolation is associated with mortality and (2) changes in exacerbation and hospitalization rates within a longitudinal cohort of COPD outpatients.

METHODS

Pseudomonas aeruginosa colonization was ascertained in monthly sputum cultures in a prospective cohort of COPD patients from 1994 to 2014. All-cause mortality was compared between patients who were colonized during their follow-up period (PA + ) and those who remained free of colonization (PA - ); Cox proportional hazards models were used. Exacerbation and hospitalization rates were evaluated by 2-rate χ 2 and segmented regression analysis for 12 months before and 24 months after PA isolation.

RESULTS

Pseudomonas aeruginosa was isolated from sputum in 73 of 181 (40%) patients. Increased mortality was seen with PA isolation: 56 of 73 (77%) PA +  patients died compared with 73 of 108 (68%) PA - patients (P = .004). In adjusted models, PA +  patients had a 47% higher risk of mortality (adjusted hazard ratio = 1.47; 95% confidence interval, 1.03-2.11; P = .04). Exacerbation rates were higher for the PA +  group during preisolation (15.4 vs 9.0 per 100 person-months, P < .001) and postisolation periods (15.7 vs 7.5, P < .001). Hospitalization rates were higher during the postisolation period among PA +  patients (6.25 vs 2.44, P < .001).

CONCLUSIONS

Tracheobronchial colonization by PA in COPD outpatients was associated with higher morbidity and mortality. This suggests that PA likely contributes to adverse clinical outcomes rather than just a marker of worsening disease.

Opportunistic Respiratory Infections in HIV Patients Attending Sukraraj Tropical and Infectious Diseases Hospital in Kathmandu, Nepal

Introduction

Opportunistic bacterial and fungal infections are the major cause of morbidity and mortality among immune suppressed HIV-positive patients. The main objective of this study was to determine bacterial and fungal organisms causing respiratory infections and their susceptibility to commonly prescribed antimicrobials among HIV patients attending a tertiary infectious disease hospital in Kathmandu.

Methods

Sputum samples were collected from the HIV-positive patients attending Sukraraj Tropical and Infectious Disease Hospital (STIDH) from August 2017 to March 2018. A total of 100 sputum samples were cultured on conventional bacterial and fungal culture media. Bacterial and fungal isolates were identified based on their colony characteristics, microscopic morphology and various biochemical tests. Antibiotic susceptibility test (AST) of bacterial isolates was performed by modified Kirby Bauer disc diffusion method.

Results

Out of 100 sputum samples cultured, 24% (n=24) showed bacterial growth, 42% (n=42) showed fungal growth and 10% (n=10) had both bacterial and fungal growth. Among bacteria, 91.6% (n=22) were monomicrobial and 8.4% (n=2) were polymicrobial in growth, of which, Klebsiella pneumoniae (37.5%) were predominant isolates, followed by Pseudomonas aeruginosa (29.2%), and Escherichia coli (16.7%). The antibiotic susceptibility test (AST) showed 68% (17/25) of bacterial isolates were multi-drug resistant (MDR) and among them 41.2% (7/17) were found to be extended spectrum β lactamase (ESBL) producers. Fungal growth was observed in 42% of samples (42/100). A total of six different species of Candida and four different genera of molds were identified. On species differentiation, Candida albicans (20%) were followed by Candida parapsilosis (4%), and Candida dubliniensis (3%); and various molds were Aspergillus fumigatus (4%), Aspergillus flavus (2%), and Penicillium species (5%). CD4 count was inversely associated with bacterial and fungal infections. Fifty percent of the patients with the fungal infections had a CD4 count below 200. No fungal organisms were isolated from HIV-positive patients under antifungal drug treatment.

Conclusion

HIV-positive patients with a CD4 count less than 200 cells/µL are more vulnerable to opportunistic infections of bacterial and fungal origin. Early isolation, identification and appropriate treatment can reduce mortality due to co-infections. Routine screening of opportunistic pathogens is critical to contain the disease progression.

Bacterial etiology in early re-admission patients with acute exacerbation of chronic obstructive pulmonary disease

Background

Repeatedly hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) are often exposed to more antibiotics, but the distribution of pathogenic bacteria in these patients is poorly understood. The objectives of this study were to analyze the distribution of pathogenic bacteria and the risk factors associated with multidrug-resistant (MDR) bacteria infection in early re-admission patients with AECOPD.

Methods

We retrospectively reviewed charts for patients with AECOPD admitted to our hospital between January 2011 and November 2012. The early re-admission group and non-early readmission group were determined by whether patients were readmitted within 31 days after discharge. Detection of potentially pathogenic microorganisms (PPMs) and MDR bacteria were analyzed. Logistic regression analysis was performed to identify independent risk factors for MDR bacteria infection.

Results

PPMs were isolated from 230 (32.0%) cases of respiratory tract specimens; MDR bacteria accounted for 24.7% (57/230). Pseudomonas aeruginosa (43.7%), Klebsiella pneumoniae (15.6%), and Acinetobacter baumannii (12.5%) were the top three PPMs in the early readmission group, while the top three PPMs in the non-early readmission group were K. pneumoniae (23.7%), P. aeruginosa (21.2%), and Streptococcus pneumoniae (17.1%). Multivariate analysis showed that use of antibiotics within 2 weeks (odds ratio [OR] 8.259, 95% confidence interval [CI] 3.056–22.322, p = 0.000) was the independent risk factor for MDR bacteria infection.

Conclusion

Non-fermentative Gram-negative bacilli (NFGNB) and enterobacteria were the predominant bacteria in early readmission patients with AECOPD. The detection rate of MDR bacteria was high which was related to the use of antibiotics within 2 weeks before admission in these patients.

Bacterial and Viral Identification Rate in Acute Exacerbation of Chronic Obstructive Pulmonary Disease in Korea

PURPOSE

The most common cause of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is respiratory infection. Most studies of bacterial or viral cause in AECOPD have been conducted in Western countries. We investigated bacterial and viral identification rates in AECOPD in Korea.

MATERIALS AND METHODS

We reviewed and analyzed medical records of 736 cases of AECOPD at the Korea University Guro Hospital. We analyzed bacterial and viral identification rates and classified infections according to epidemiological factors, such as Global Initiative for Chronic Obstructive Lung Disease stage, mortality, and seasonal variation.

RESULTS

The numbers of AECOPD events involving only bacterial identification, only viral identification, bacterial-viral co-identification, and no identification were 200 (27.2%), 159 (21.6%), 107 (14.5%), and 270 (36.7%), respectively. The most common infectious bacteria identified were Pseudomonas aeruginosa (13.0%), Streptococcus pneumoniae (11.4%), and Haemophilus influenzae (5.3%); the most common viruses identified were influenza virus (12.4%), rhinovirus (9.4%), parainfluenza virus (5.2%), and metapneumovirus (4.9%). The bacterial identification rate tended to be higher at more advanced stages of chronic obstructive pulmonary disease (p=0.020 overall, p=0.011 for P. aeruginosa, p=0.048 for S. pneumoniae). Staphylococcus aureus and Klebsiella pneumoniae were identified more in mortality group (p=0.003 for S. aureus, p=0.009 for K. pneumoniae). All viruses were seasonal (i.e., greater prevalence in a particular season; p<0.050). Influenza virus and rhinovirus were mainly identified in the winter, parainfluenza virus in the summer, and metapneumovirus in the spring.

CONCLUSION

This information on the epidemiology of respiratory infections in AECOPD will improve the management of AECOPD using antibiotics and other treatments in Korea.

Airway surface liquid from smokers promotes bacterial growth and biofilm formation via iron-lactoferrin imbalance

Background

Smoking is a leading cause of respiratory infections worldwide. Tobacco particulate matter disrupts iron homeostasis in the lungs and increases the iron content in the airways of smokers. The airway epithelia secrete lactoferrin to quench iron required for bacteria to proliferate and cause lung infections. We hypothesized that smokers would have increased bacterial growth and biofilm formation via iron lactoferrin imbalance.

Methods

We collected bronchoalveolar lavage (BAL) samples from non-smokers and smokers. We challenged these samples using a standard inoculum of Staphylococcus aureus and Pseudomonas aeruginosa and quantified bacterial growth and biofilm formation. We measured both iron and lactoferrin in the samples. We investigated the effect of supplementing non-smoker BAL with cigarette smoke extract (CSE) or ferric chloride and the effect of supplementing smoker BAL with lactoferrin on bacterial growth and biofilm formation.

Results

BAL from smokers had increased bacterial growth and biofilm formation compared to non-smokers after both S. aureus and P. aeruginosa challenge. In addition, we found that samples from smokers had a higher iron to lactoferrin ratio. Supplementing the BAL of non-smokers with cigarette smoke extract and ferric chloride increased bacterial growth. Conversely, supplementing the BAL of smokers with lactoferrin had a concentration-dependent decrease in bacterial growth and biofilm formation.

Conclusion

Cigarette smoking produces factors which increase bacterial growth and biofilm formation in the BAL. We propose that smoking disrupts the iron-to-lactoferrin in the airways. This finding offers a new avenue for potential therapeutic interventions to prevent respiratory infections in smokers.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0743-x) contains supplementary material, which is available to authorized users.

Upper airway involvement in bronchiectasis is marked by early onset and allergic features

The association of bronchiectasis with chronic rhinosinusitis (CRS) has been reported. However, apart from primary ciliary dyskinesia (PCD) and cystic fibrosis (CF), predisposing conditions have not been established. We aimed to define clinical and laboratory features that differentiate patients with bronchiectasis with upper airway symptoms (UASs) and without PCD from patients without UASs.

We reviewed charts of adults with bronchiectasis, excluding CF and PCD. UASs were defined as nasal discharge most days of the year, sinusitis or nasal polyps. Laboratory data included IgG, total IgE, blood eosinophils, sputum bacteriology and lung function. A radiologist blinded to UAS presence scored bronchiectasis (Reiff score) and sino-nasal pathology (Lund–Mackay score).

Of 197 patients, for the 70 (35%) with UASs, symptoms started earlier (34±25 versus 46±24 years; p=0.001), disease duration was longer (median 24 versus 12 years; p=0.027), exacerbations were more frequent (median 3 versus 2 per year; p=0.14), and peripheral blood eosinophil (median 230 versus 200 μL⁻¹; p=0.015) and total IgE (median 100 versus 42 IU·mL⁻¹; p=0.085) levels were higher. The sinus computed tomography score was independently associated with exacerbations, with 1 point on the Lund–Mackay score associated with a 1.03-fold increase in the number of exacerbations per year (95% CI 1.0–1.05; p=0.004).

These findings may implicate a higher disease burden in patients with UASs. We hypothesise that UASs precede and may in some cases lead to the development of bronchiectasis.

Involvement of the upper airway in patients with bronchiectasis is associated with an early age of onset and allergic featureshttp://ow.ly/1BuK30gWDrN

A Prospective Study of Bacteriological Etiology in Hospitalized Acute Exacerbation of COPD Patients: Relationship with Lung Function and Respiratory Failure

OBJECTIVES

Bacterial infections are the major cause of acute exacerbation of COPD (AE-COPD). The relationship between lung functions and respiratory failure (arterial blood gas parameters) with the etiology of AE-COPD has not been clearly understood. We conducted this study to determine the bacterial profile in AE-COPD and to identify the associated risk factors and drug sensitivity pattern.

MATERIAL AND METHODS

Seventy-two patients hospitalized for AE-COPD were prospectively evaluated. Quantitative sputum culture, blood gas analysis, and drug sensitivity testing were performed at the time of admission, and pulmonary function testing was performed 6 weeks after discharge as per standard guidelines.

RESULTS

Bacterial pathogens were isolated in 34 (47.22%) cases. Pathogens isolated were Pseudomonas aeruginosa (38.23%), Klebsiella pneumoniae (29.41%), Staphylococcus aureus (23.53%), Streptococcus pneumoniae (5.88%), and Acinetobacter spp. (2.94%). Isolation of bacterial pathogen was observed in patients with advancing age (p=0.02), frequent exacerbations (p<0.001), systemic steroid use (p=0.005), and deranged lung function (p=0.02). Binary logistic regression analysis revealed that higher partial pressure of carbon dioxide (PaCO2) was independently associated with isolation of K. pneumoniae (p=0.025) and P. aeruginosa (p=0.001). Additional independent factors that favor isolation of K. pneumoniae were age >55 years (p=0.017) and systemic steroid use (p=0.017). Antibiotic sensitivity testing showed that ciprofloxacin and piperacillin/tazobactum were effective in 27/34 (79.41%) of isolates followed by gentamycin in 26/34 (76%).

CONCLUSION

Hypercapnic respiratory failure is an independent risk factor for isolation of K. pneumoniae and P. aeruginosa in addition to advanced age and systemic steroid use. These findings may be an important adjunct in deciding the initial antibiotic therapy.

The respiratory threat posed by multidrug resistant Gram-negative bacteria

Respiratory infections are a major cause of global mortality and morbidity. In recent years, an increased incidence of multidrug-resistant (MDR) Gram-negative bacteria (GNB) has been described. Microorganisms such as Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae or Acinetobacter baumannii have been identified as causative pathogens of different respiratory tract infections. Several studies have detected MDR-GNB in patients with community-acquired and nosocomial pneumonia. Furthermore, MDR-GNB have also been isolated in patients with chronic obstructive pulmonary disease and bronchiectasis having acute or chronic bronchial infection. Prevalence varies depending on the geographical area but MDR-GNB has been reported in the Asia-Pacific region, Europe and the United States, reaching rates of 70% in hospital-acquired infection. The presence of MDR-GNB has been related to poor clinical outcomes, including increased mortality, although data regarding this relationship are limited. This is probably linked to inappropriate selection of empiric antibiotic treatment; this poses a threat of widespread resistance. GNB antibiotic resistance and the absence of new antibiotics are a major concern given limited treatment options; an aspect that deserves future research. We review current literature, highlight prevalence of MDR-GNB in different respiratory infections and explore their impact on clinical outcomes.

Precipitating causes and outcomes of chronic obstructive pulmonary disease exacerbation at a tertiary care center in northeast Thailand

Background: Acute exacerbation of chronic obstructive pulmonary disease (COPD) is a leading cause of hospitalization and economic burden. Frequent exacerbations impair quality of life and effect decline of lung function.

Objective: We evaluated characteristics of COPD patients with frequent exacerbations. The precipitating causes, outcomes, hospital stay, and cost of admission were also determined.

Methods: The study population included COPD patients admitted because of acute COPD exacerbation at Srinagarind Hospital between 1 January 2006 and 31 December 2010.

Results: Over the 5-year period, 183 patients were admitted. Their mean age was 74.9 (SD 9.28) years and the male to female ratio was 170:13. Most patients (144; 79%) had one exacerbation per year and 39 (21%) had more than one per year. The group with more exacerbations, had a higher stage of the disease than those with only one exacerbation (p = 0.023), but there was no significant difference in the mortality rate (18% vs 14%, p = 0.53). A total of 245 episodes of acute exacerbation of COPD occurred in 183 patients. The mean duration of symptoms was 4.1 (SD 3.46) days. Forty-seven percent presented with Anthonisen type III, 42.4% with Anthonisen type II, and 10.6% with Anthonisen type I exacerbations. For 44 exacerbations (18%), the precipitating causes were not determined. The most common precipitating cause was pneumonia, which occurred in 90 episodes (36.7%). The second common was bronchitis (27.8%); followed by heart failure (8.2%), infected bronchiectasis (5.3%), diarrhea (1.2%), acute urinary retention (0.8%), unstable angina (0.4%), pneumothorax (0.4%), urinary tract infection (0.4%), atrial fibrillation (0.4%) and drug induced cough (0.4%). The organisms responsible for respiratory tract infection were identified in 31% cases of pneumonia and 18% of bronchitis cases. The top three common pathogens for pneumonia were Pseudomonas aeruginosa (9%), Acinetobacter baumannii (8%), and Klebsiella pneumoniae (8%). The top three common pathogens for bronchitis were P aeruginosa (7%), Haemophilus influenza (6%), and K pneumoniae (4%). About one quarter (25.3%) of acute exacerbations were complicated by respiratory failure. The mean duration of admission was 17.3 days (range 1-682 days). The mean cost of admission per exacerbation was 80,010 Thai baht (US $2,666) (range, 2,779-3,433,108 baht). The total cost for 245 exacerbations was 19.6 million baht ($653,000).

Conclusion: Respiratory tract infections were common causes of COPD exacerbation and one quarter of which developed respiratory failure. Preventive measures such as vaccination, smoking cessation, lung rehabilitation, and appropriate drug use are helpful.

Acute exacerbation of COPD

The literature of acute exacerbation of chronic obstructive pulmonary disease (COPD) is fast expanding. This review focuses on several aspects of acute exacerbation of COPD (AECOPD) including epidemiology, diagnosis and management. COPD poses a major health and economic burden in the Asia-Pacific region, as it does worldwide. Triggering factors of AECOPD include infectious (bacteria and viruses) and environmental (air pollution and meteorological effect) factors. Disruption in the dynamic balance between the 'pathogens' (viral and bacterial) and the normal bacterial communities that constitute the lung microbiome likely contributes to the risk of exacerbations. The diagnostic approach to AECOPD varies based on the clinical setting and severity of the exacerbation. After history and examination, a number of investigations may be useful, including oximetry, sputum culture, chest X-ray and blood tests for inflammatory markers. Arterial blood gases should be considered in severe exacerbations, to characterize respiratory failure. Depending on the severity, the acute management of AECOPD involves use of bronchodilators, steroids, antibiotics, oxygen and noninvasive ventilation. Hospitalization may be required, for severe exacerbations. Nonpharmacological interventions including disease-specific self-management, pulmonary rehabilitation, early medical follow-up, home visits by respiratory health workers, integrated programmes and telehealth-assisted hospital at home have been studied during hospitalization and shortly after discharge in patients who have had a recent AECOPD. Pharmacological approaches to reducing risk of future exacerbations include long-acting bronchodilators, inhaled steroids, mucolytics, vaccinations and long-term macrolides. Further studies are needed to assess the cost-effectiveness of these interventions in preventing COPD exacerbations.

Predicting Healthcare Utilization by Patients Admitted for COPD Exacerbation

BACKGROUND

Healthcare utilization, especially length of hospital stay and ICU admission, for acute exacerbation of chronic obstructive pulmonary disease (AECOPD) determine overall outcomes in terms of morbidity, mortality and cost burden. Predicting prolonged hospital stay (PHS) and prolonged intensive care (PIC) for AECOPD is useful for rational allocation of resources in healthcare centres.

AIM

To characterize the pattern of healthcare utilization by COPD patients hospitalized for acute exacerbation, and to identify clinical and laboratory predictors of 'prolonged hospital stay' (PHS) and 'prolonged intensive care'(PIC).

MATERIALS AND METHODS

This study attempted through retrospective data analysis, to identify risk factors and evolve prediction models for increased healthcare utilization namely PHS and PIC for AECOPD. The data were extracted from 255 eligible admissions for AECOPD by 166 patients from Aug 2012 to July 2013. Logistic regression analysis was used for identifying predictors and models were tested with area under receiver operating characteristic curve.

RESULTS

Independent predictors of prolonged hospital stay (≥ 6 days) were chronic respiratory failure at baseline, low saturation at admission, high HbA1c level and positive isolates in sputum culture. Independent predictors of prolonged intensive care (for ≥ 48 hours) were past history of pulmonary tuberculosis, chronic respiratory failure at baseline, low saturation at admission, high leukocyte count and positive culture isolates in sputum. Prediction models evolved from variables available at admission showed AUC 0.805 (95% CI 0.729 - 0.881) and 0.825 (95% CI 0.75 - 0.90) for PHS and ICU admissions respectively.

CONCLUSION

Our prediction models derived from simple and easily available variables show good discriminative properties in predicting PHS and PIC for AECOPD. When prospectively validated, these models are useful for rational allocation of services especially in resource limited settings.

Fluoroquinolones versus β-Lactam/β-Lactamase Inhibitors in Outpatients with Chronic Obstructive Pulmonary Disease and Pneumonia: A Nationwide Population-Based Study

Background

Studies on the association between antibiotic treatment and outcomes in outpatients with chronic obstructive pulmonary disease (COPD) and pneumonia are scarce. This study aimed to evaluate the effectiveness of fluoroquinolones and β-lactam/β-lactamase inhibitors for pneumonia in COPD outpatients.

Methods

We conducted a retrospective cohort study and identified 4,851 episodes of pneumonia among COPD outpatients treated with fluoroquinolones or β-lactam/β-lactamase inhibitors from the Taiwan National Health Insurance Research Database during 2002–2011. Using the propensity score analysis, 1,296 pairs of episodes were matched for the demographic and clinical characteristics. The primary outcome was pneumonia/empyema-related hospitalization or emergency department (ED) visits, and the secondary outcomes were treatment failure, all-cause mortality and medical costs within 30 days.

Results

Compared with episodes treated with β-lactam/β-lactamase inhibitors, episodes treated with fluoroquinolones had similar clinical outcomes. The rates of pneumonia/empyema-related hospitalization or ED visits were 3.9% and 3.5% in the fluoroquinolone and β-lactam/β-lactamase inhibitor groups, respectively (adjusted hazard ratio [aHR], 1.11; 95% confidence interval [CI], 0.74–1.66). The percentage of treatment failure and all-cause mortality were 28.2% versus 31.3% (adjusted odds ratio, 0.86; 95% CI, 0.73–1.02) and 0.5% versus 0.4% (aHR, 1.40; 95% CI, 0.45–4.41) in the fluoroquinolone and β-lactam/β-lactamase inhibitor groups, respectively. The medical expenditures, including total medical costs (528 versus 455 US dollars) and pneumonia-related costs (202 vs. 155 USD) were also balanced between the two treatment groups (both P >0.05).

Conclusions

For pneumonia in COPD outpatients, fluoroquinolones were associated with similar clinical outcomes and medical expenditures compared with β-lactam/β-lactamase inhibitors.

Multicentre investigation of pathogenic bacteria and antibiotic resistance genes in Chinese patients with acute exacerbation of chronic obstructive pulmonary disease

OBJECTIVE

A prospective observational study to investigate the distribution and antimicrobial resistance of pathogenic bacteria in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in Beijing, China.

METHODS

Patients with AECOPD were recruited from 11 general hospitals. Sputum specimens were cultured and bacteria identified. Antibiotic susceptibility was determined for each isolate, and presence of antibiotic resistance genes was evaluated using polymerase chain reaction.

RESULTS

Pathogenic bacteria were isolated from 109/318 patients (34.28%); 124 isolates of 22 pathogenic bacterial species were identified, including Klebsiella pneumoniae (16.94%), Pseudomonas aeruginosa (16.94%), Acinetobacter baumannii (11.29%), Streptococcus pneumoniae (8.87%), and Staphylococcus aureus (7.26%). S. aureus was sensitive to tigecycline, teicoplanin, vancomycin and linezolid but resistant to penicillin and levofloxacin. K.pneumoniae, P. aeruginosa, A. baumannii and E. coli were susceptible to amikacin and cefoperazone.

CONCLUSIONS

K. pneumoniae and P. aeruginosa are the most common pathogenic bacteria in AECOPD cases in Beijing, China. Our antibiotic resistance findings may be helpful in selecting antibiotic therapy.

Procalcitonin and C-reactive protein cannot differentiate bacterial or viral infection in COPD exacerbation requiring emergency department visits

Background

Viral and bacterial infections are the most common causes of chronic obstructive pulmonary disease (COPD) exacerbations. Whether serum inflammatory markers can differentiate bacterial from virus infection in patients with COPD exacerbation requiring emergency department (ED) visits remains controversial.

Methods

Viral culture and polymerase chain reaction (PCR) were used to identify the viruses in the oropharynx of patients with COPD exacerbations. The bacteria were identified by the semiquantitative culture of the expectorated sputum. The peripheral blood white blood cell (WBC) counts, serum C-reactive protein (CRP), procalcitonin (PCT), and clinical symptoms were compared among patients with different types of infections.

Results

Viruses were isolated from 16 (22.2%) of the 72 patients enrolled. The most commonly identified viruses were parainfluenza type 3, influenza A, and rhinovirus. A total of 30 (41.7%) patients had positive bacterial cultures, with the most commonly found bacteria being Haemophilus influenzae and Haemophilus parainfluenzae. Five patients (6.9%) had both positive sputum cultures and virus identification. The WBC, CRP, and PCT levels of the bacteria-positive and bacteria-negative groups were not statistically different. Multivariate analysis showed that patients with increased sputum volumes during the COPD exacerbations had higher risks of recurrent exacerbations in the 1-year period following the first exacerbation.

Conclusion

WBC, CRP, or PCT could not differentiate between bacterial and viral infections in patients with COPD exacerbation requiring ED visits. Those with increased sputum during a COPD exacerbation had higher risks for recurrent exacerbations.

Prise en charge des exacerbations : de la ville à l’hôpital

La Société de pneumologie de langue française définie l’exacerbation aiguë de bronchopneumopathie chronique obstructive comme une majoration des symptômes respiratoires au-delà des variations quotidiennes (en pratique, d’une durée ≥ 48 h ou justifiant une modification thérapeutique).

La cause de ces exacerbations est principalement infectieuse : virale (rhinovirus, virus influenzae et parainfluenzae, coronavirus, adénovirus et virus respiratoire syncytial) ou bactérienne (principalement, Haemophilus influenzae, Streptococcus pneumoniae et Moraxella catarrhalis). Elles peuvent également résulter de l’exposition à certains polluants : NO₂, SO₂, ozone et pollution particulaire (PM10 et PM2,5). Elle reste indéterminée dans près de 30 % des cas.

Les diagnostics différentiels incluent les pneumopathies infectieuses, les pneumothorax, les poussées d’insuffisance cardiaque et les embolies pulmonaires.

La présence de signes de gravité conditionne l’hospitalisation : signes d’insuffisance respiratoire aiguë, de choc ou de défaillance neurologique, mais aussi en cas de patient fragile, d’absence de soutien familial à domicile ou de réponse au traitement initial.

Le traitement consiste en une majoration des bronchodilatateurs, une kinésithérapie respiratoire, une antibiothérapie en cas d’expectoration franchement purulente. La prescription de corticoïdes systémiques ne doit pas être systématique. La dose recommandée est de 0,5 mg/kg sur une courte période (5–7 jours). Lors d’une hospitalisation, une oxygénothérapie et une thromboprophylaxie peuvent être instaurées. La ventilation non invasive est principalement indiquée en cas de persistance d’une hypercapnie malgré un traitement médical optimal. Que le patient soit pris en charge en ambulatoire ou en hospitalisation, une réévaluation clinique à 48–72 h est indispensable.

Bufei Jianpi granules improve skeletal muscle and mitochondrial dysfunction in rats with chronic obstructive pulmonary disease

Background

Bufei Jianpi granules has been confirmed effective in improving pulmonary function, alleviating acute exacerbations, improving six-minute walk distance and quality of life, and benefited in 12-month follow-up in chronic obstructive pulmonary disease (COPD) patients with syndrome of lung-spleen qi deficiency. Skeletal muscle dysfunction (SMD), an important extrapulmonary complication, occurs in the very initiation of COPD and is closely related to morbidity and mortality. To evaluate the efficacy of Bufei Jianpi granules on SMD, we observed skeletal muscular function and histomorphology, mitochondrial morphormetry and proteins in COPD rats induced by cigarette-smoke and Klebsiella pneumoniae.

Methods

Seventy-two Sprague–Dawley rats were randomized into Control + Saline, Control + Bufei Jianpi, Control + Aminophylline, COPD + Saline, COPD + Bufei Jianpi and COPD + Aminophylline groups. From week 9 to 20, rats were administrated intragastricly by normal saline, Bufei Jianpi granules and aminophylline, respectively. Muscular tension and fatigue index of intercostal muscle, quadriceps, biceps and soleus were detected by using electrophysiological technology. Pathological and ultrastructural changes and expressions of mitochondrial Bcl-2 nineteen-kilodalton interacting protein 3 (Bnip3) and cytoplasm cytochrome C (Cyto C) in the four skeletal muscles were observed by using optical and electron microscope and western blotting.

Results

There was no statistical difference among the control rats treated with saline, Bufei Jianpi granules or aminophylline in above-mentioned parameters. Muscular tension, mitochondria volume density (Vv) and compared membrane surface (δm) of the four muscles were significantly lower in COPD + Saline group compared to Control + Saline group, while fatigue index, mitochondria surface area (δ), Bnip3 and Cyto C were higher (P < 0.05). COPD rats showed more morphological changes in muscle tissues than controls, such as atrophy, degeneration, necrosis and matrix hyperplasia. Utrastructurally, mitochondria populations decreased significantly in the four muscles, and were shrunken and even cavitation changed. The up-mentioned parameters were improved in Bufei Jianpi group (P < 0.05) in the four muscles.

Conclusions

Bufei Jianpi granules can improve skeletal muscle function via improving mitochondria population and function, reducing apoptotic factors such as Bnip3 and Cyto C, and is more effective than aminophylline.

[Management of COPD exacerbations: from primary care to hospitalization]

The Société de pneumologie de langue française defines acute exacerbation of chronic obstructive pulmonary disease (AE COPD) as an increase in daily respiratory symptoms, basically duration ≥ 48h or need for treatment adjustment. Etiology of EA COPD are mainly infectious, viral (rhinovirus, influenzae or parainfluenzae virus, coronavirus, adenovirus and respiratory syncytial virus) or bacterial (Haemophilus influenzae, Streptococcus pneumoniae, or Moraxella catarrhalis). Pollutant exposure can also lead to AE COPD, such as NO2, SO2, ozone or particulates (PM10 and PM2.5). In 30% the etiology remains unknown. Differential diagnoses of AE COPD include infectious pneumonia, pneumothorax, acute heart failure and pulmonary embolism. Presences of signs of severity impose hospitalization: signs of respiratory distress, shock, acute confusion but also fragile patients, insufficient home support or absence of response to initial treatment. AE COPD treatments consist on increase in bronchodilators, chest physiotherapy, and antibiotics if sputum is frankly purulent. Systemic corticosteroids should not be systematic. Recommended dose is 0.5 mg/kg on short course (5-7 days). During hospitalization, oxygen supplementation and thromboprophylaxis could be prescribed. The main interest in non-invasive ventilation is persistent hypercapnia despite optimal medical management. During ambulatory management or hospitalization, clinical assessment at 48-72 h is mandatory.

Nano-antibiotics in chronic lung infection therapy against Pseudomonas aeruginosa

Antibiotic encapsulation into nanoparticle carriers has emerged as a promising inhaled antibiotic formulation for treatment of chronic Pseudomonas aeruginosa lung infection prevalent in chronic obstructive pulmonary diseases. Attributed to their prolonged lung retention, sustained antibiotic release, and mucus penetrating ability, antibiotic nanoparticles, or nano-antibiotics in short, can address the principal weakness of inhaled antibiotic solution, i.e. low antibiotic exposure in the vicinity of P. aeruginosa biofilm colonies resulting in diminished anti-pseudomonal efficacy after repeated uses. This review details the current state of development and limitations of the two most widely studied forms of nano-antibiotics, i.e. liposomes and polymer nanoparticles. Factors in their formulation that influence the anti-pseudomonal efficacy in vitro and in vivo, such as liposome's membrane rigidity, surface charge, size, and polymer hydrophobicity, are discussed. This review reveals that the superior anti-pseudomonal efficacy of liposomal antibiotics to free antibiotics has been clearly established when they are correctly formulated, with several liposomal antibiotic formulations are currently undergoing clinical trials. Liposomal antibiotics, nevertheless, are not without limitation due to their weak physicochemical stability. In contrast, only mucus penetrating ability of the more stable polymeric nano-antibiotics has been established, while their anti-pseudomonal efficacy has only been examined in vitro from which their superiority to free antibiotics has not been ascertained. Lastly, future research needs to bring liposome and polymer-based nano-antibiotics closer to their clinical realization are identified.

16S rDNA-based metagenomic analysis of dental plaque and lung bacteria in patients with severe acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are leading causes of mortality in hospital intensive care units. We sought to determine whether dental plaque biofilms might harbor pathogenic bacteria that can eventually cause lung infections in patients with severe AE-COPD.

MATERIAL AND METHODS

Paired samples of subgingival plaque biofilm and tracheal aspirate were collected from 53 patients with severe AE-COPD. Total bacterial DNA was extracted from each sample individually for polymerase chain reaction amplification and/or generation of bacterial 16S rDNA sequences and cDNA libraries. We used a metagenomic approach, based on bacterial 16S rDNA sequences, to compare the distribution of species present in dental plaque and lung.

RESULTS

Analysis of 1060 sequences (20 clones per patient) revealed a wide range of aerobic, anaerobic, pathogenic, opportunistic, novel and uncultivable bacterial species. Species indistinguishable between the paired subgingival plaque and tracheal aspirate samples (97-100% similarity in 16S rDNA sequence) were dental plaque pathogens (Aggregatibacter actinomycetemcomitans, Capnocytophaga sputigena, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola) and lung pathogens (Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Streptococcus pneumoniae). Real-time polymerase chain reaction of 16S rDNA indicated lower levels of Pseudomonas aeruginosa and Porphyromonas gingivalis colonizing the dental plaques compared with the paired tracheal aspirate samples.

CONCLUSION

These results support the hypothesis that dental bacteria may contribute to the pathology of severe AE-COPD.

[Lower respiratory tract infections related to Stenotrophomonas maltophilia and Acinetobacter baumannii]

Stenotrophomonas maltophilia and Acinetobacter baumannii are both non-fermenting ubiquitous Gram-negative bacilli. The incidence of lower respiratory tract infections related to these microorganisms is increasing, especially in intensive care units. Their capacity to acquire resistance against several antimicrobials is challenging for clinicians and microbiologists. Despite their low virulence, these pathogens are responsible for colonization and infection in patients with comorbidities, immunosuppression, and critically ill patients. S. maltophilia and A. baumannii are mainly identified in nosocomial infections: ventilator-associated pneumonia, bacteremia and surgical wound infection. Infections related to these microorganism are associated with high mortality and morbidity. Trimethoprime-sulfamethoxazole and carbapenem are the first line treatment for infections related to S. maltophilia and A. baumannii respectively. However, the increasing rate of resistance against these agents results in difficulties in treating patients with infections related to these pathogens. New antimicrobial agents and further randomized studies are needed to improve the treatment of these infections. Prevention of spared of these multidrug-resistant bacteria is mandatory, including hand-hygiene, environment cleaning, and limited usage of large spectrum antibiotics.

A rat model for stable chronic obstructive pulmonary disease induced by cigarette smoke inhalation and repetitive bacterial infection

To develop a stable chronic obstructive pulmonary disease (COPD) model in rats. Sprague-Dawley rats were treated with cigarette-smoke inhalation (CSI) for 12 weeks, repetitive bacterial infection (RBI) for 8 weeks, or the combination of the two (CCR) for 12 weeks and followed up for the additional 20 weeks. Tidal volume (V(T)), peak expiratory flow (PEF) and 50% V(T) expiratory flow (EF(50)), histological changes in the lungs, and levels of the cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-8, and IL-10 in serum and bronchial alveolar lavage fluid (BALF) were examined at intervals during the 32 week study period. The right ventricular hypertrophy index (RVHI) was also determined at the same times. V(T), PEF, and EF(50) were decreased in rats with COPD compared to the control. The expression of TNF-α, IL-8 and IL-10 increased in both serum and BALF with a similar trend. Bronchiole and arteriole wall thickness and the degree of bronchiole stenosis and alveolar size increased in COPD rats. RVHI was reduced gradually following the treatment. All of these changes were more pronounced in the CCR-treatment group than in the other groups. Our results have shown that CSI or RBI alone can induce COPD in rats, but that the combination of CSI with RBI induces a stable COPD that has more similarity to complications seen in patients with COPD. This combination may therefore provide a more appropriate model for study of human COPD.

Assessment of some inflammatory biomarkers as predictors of outcome of acute respiratory failure on top of chronic obstructive pulmonary disease and evaluation of the role of bacteria

Objective. To study the value of the inflammatory markers (interleukin-6 (IL-6), interleukin-8 (IL-8), and C-reactive protein (CRP)) in predicting the outcome of noninvasive ventilation (NIV) in the management of acute respiratory failure (ARF) on top of chronic obstructive pulmonary disease (COPD) and the role of bacteria in the systemic inflammation. Methods. Thirty three patients were subjected to standard treatment plus NIV, and accordingly, they were classified into responders and nonresponders. Serum samples were collected for IL-6, IL-8, and CRP analysis. Sputum samples were taken for microbiological evaluation. Results. A wide spectrum of bacteria was revealed; Gram-negative and atypical bacteria were the most common (31% and 28% resp.; single or copathogen). IL-8 and dyspnea grade was significantly higher in the non-responder group (P = 0.01 and 0.023 resp.). IL-6 correlated positivity with the presence of infection and type of pathogen (P = 0.038 and 0.034 resp.). Gram-negative bacteria were associated with higher significant IL-6 in comparison between others (196.4 ± 239.1 pg/dL; P = 0.011) but insignificantly affected NIV outcome (P > 0.05). Conclusions. High systemic inflammation could predict failure of NIV. G-ve bacteria correlated with high IL-6 but did not affect the response to NIV.

Antimicrobial drug-resistant microbes associated with hospitalized community-acquired and healthcare-associated pneumonia: a multi-center study in Taiwan

BACKGROUND/PURPOSE

Community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP) may be caused by potential antimicrobial drug-resistant (PADR) microbes. The aims of this study were to evaluate the incidences and risk factors associated with PADR microbes observed in patients with pneumonia occurring outside the hospital setting in Taiwan.

METHODS

We conducted a retrospective study of patients with CAP or HCAP admitted to six medical centers in the northern, central, and southern regions of Taiwan in 2007. The pathogens were evaluated by microbiological specimens within 72 hours after admission. The patients' comorbidities, pathogens, and outcomes were evaluated. The risk factors of PADR microbes were identified by logistic regression analysis.

RESULTS

The enrolled patients exhibited HCAP (n=713) and CAP (n=933). The pathogens associated with HCAP (n=383) and CAP (n=441) included Pseudomonas spp. (29%vs. 10%, p<0.001), Klebsiella spp. (24% vs. 25%, p=0.250), Escherichia coli (6% vs. 8%, p=0.369), Haemophilus influnezae (3% vs. 7%, p=0.041), Streptococcus pneumoniae (2% vs. 6%, p=0.003) and methicillin-resistant Staphylococcus aureus (MRSA) (8% vs. 4%, p=0.008). The core pathogens of CAP and HCAP differed among the three regions of Taiwan. PADR microbes, including Pseudomonas spp. (n=191), Acinetobacter spp. (n=41), MRSA (n=49) and cefotaxime- or ceftazidime-resistant Enterbacteriaceae (n=25), were isolated from 13% of patients with CAP and 23% of patients with HCAP. Previous hospitalization, and neoplastic and neurological diseases were significant risk factors for acquiring PADR microbes.

CONCLUSION

PADR microbes were common in patients with HCAP and CAP in Taiwan. Broad-spectrum antibiotics targeting PADR microbes should be administered to patients who have undergone previous hospitalization and who exhibit neurological disorders and/or malignancies.

Guidelines for the management of adult lower respiratory tract infections--summary

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Pseudomonas aeruginosa and the host pulmonary immune response

Pseudomonas aeruginosa is a highly adaptable, opportunistic pathogen that is commonly found in the environment. It can infect a number of sites in the body and disseminate. It can cause both acute and chronic pulmonary infection and the acuity of infection and accompanying inflammatory phenotype is determined, for the most part, by the host. Although P. aeruginosa has been a successful opportunist in the context of a number of different disease states, it has been best studied in the context of cystic fibrosis (CF). The adaptability of P. aeruginosa has enabled it to adjust quickly to the CF airway, transitioning from initial colonization to chronic infection. The organism quickly expresses virulence factors that allow it to circumvent some elements of the host immune response and, even more importantly, quickly develops antimicrobial resistance. In the case of CF, chronic infection resulting in progressive lung damage, coupled with antimicrobial resistance, becomes an increasingly important issue as individuals with CF live longer. It is for these reasons that both organism- and host-targeted immunotherapies are being increasingly explored.

N-acetylcysteine inhibit biofilms produced by Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa is a common pathogen in chronic respiratory tract infections. It typically makes a biofilm, which makes treatment of these infections difficult. In this study, we investigated the inhibitory effects of N-acetylcysteine (NAC) on biofilms produced by P. aeruginosa.

RESULTS

We found that minimum inhibitory concentrations (MICs) of NAC for most isolates of P. aeruginosa were 10 to 40 mg/ml, the combination of NAC and ciprofloxacin (CIP) demonstrated either synergy (50%) or no interaction (50%) against the P. aeruginosa strains. NAC at 0.5 mg/ml could detach mature P. aeruginosa biofilms. Disruption was proportional to NAC concentrations, and biofilms were completely disrupted at 10 mg/ml NAC. Analysis using COMSTAT software also showed that PAO1 biofilm biomass decreased and its heterogeneity increased as NAC concentration increased. NAC and ciprofloxacin showed significant killing of P. aeruginosa in biofilms at 2.5 mg/ml and > 2 MIC, respectively (p < 0.01). NAC-ciprofloxacin combinations consistently decreased viable biofilm-associated bacteria relative to the control; this combination was synergistic at NAC of 0.5 mg/ml and CIP at 1/2MIC (p < 0.01). Extracellular polysaccharides (EPS) production by P. aeruginosa also decreased by 27.64% and 44.59% at NAC concentrations of 0.5 mg/ml and 1 mg/ml.

CONCLUSIONS

NAC has anti-bacterial properties against P. aeruginosa and may detach P. aeruginosa biofilms. Use of NAC may be a new strategy for the treatment of biofilm-associated chronic respiratory infections due to P. aeruginosa, although it would be appropriate to conduct clinical studies to confirm this.

Chronic wounds and the medical biofilm paradigm

There is a growing recognition that biofilms are the principal cause of wound chronicity. The development of treatments for wound biofilms raises the prospect that chronic wounds can be treated, potentially saving many patients' lives.

Bibliography. Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 November 2007 and 31 October 2008 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.