Lipid A modification of colistin-resistant Klebsiella pneumoniae does not alter innate immune response in a mouse model of pneumonia.

Polymyxin resistance in carbapenem-resistant Klebsiella pneumoniae bacteria is associated with high morbidity and mortality in vulnerable populations throughout the world. Ineffective antimicrobial activity by these last resort therapeutics can occur by transfer of mcr-1, a plasmid-mediated resistance gene, causing modification of the lipid A portion of lipopolysaccharide (LPS) and disruption of the interactions between polymyxins and lipid A. Whether this modification alters the innate host immune response or carries a high fitness cost in the bacteria is not well established. To investigate this, we studied infection with K. pneumoniae (KP) ATCC 13883 harboring either the mcr-1 plasmid (pmcr-1) or the vector control (pBCSK) ATCC 13883. Bacterial fitness characteristics of mcr-1 acquisition were evaluated. Differentiated human monocytes (THP-1s) were stimulated with KP bacterial strains or purified LPS from both parent isolates and isolates harboring mcr-1. Cell culture supernatants were analyzed for cytokine production. A bacterial pneumonia model in WT C57/BL6J mice was used to monitor immune cell recruitment, cytokine induction, and bacterial clearance in the bronchoalveolar lavage fluid (BALF). Isolates harboring mcr-1 had increased colistin MIC compared to the parent isolates but did not alter bacterial fitness. Few differences in cytokines were observed with purified LPS from mcr-1 expressing bacteria in vitro. However, in a mouse pneumonia model, no bacterial clearance defect was observed between pmcr-1-harboring KP and parent isolates. Consistently, no differences in cytokine production or immune cell recruitment in the BALF were observed, suggesting that other mechanisms outweigh the effect of these lipid A mutations in LPS.

Yersinia pestis and pneumonic plague: Insight into how a lethal pathogen interfaces with innate immune populations in the lung to cause severe disease.

Yersinia pestis is the causative agent of bubonic, septicemic and pneumonic plague. The historical importance and potential of plague to re-emerge as a threat worldwide are indisputable. The most severe manifestion of plague is pneumonic plague, which results in disease that is 100% lethal without treatment. Y. pestis suppresses host immune responses early in the lung to establish infection. The later stages of infection see the rapid onset of hyperinflammatory responses that prove lethal. The study of Y. pestis host/pathogen interactions have largely been investigated during bubonic plague and with attenuated strains in cell culture models. There remains a somewhat limited understanding of the interactions between virulent Y. pestis and immune populations in the lung that drive severe disease. In this review we give a broad overview of the progression of pneumonic plague and highlighting how Y. pestis interfaces with host innate immune populations in the lung to cause lethal disease.

Phenotypical characteristics of nontuberculous mycobacterial infection in patients with bronchiectasis.

BACKGROUND: The global mortality and morbidity rates of bronchiectasis patients due to nontuberculous mycobacteria (NTM) pulmonary infection are on a concerning upward trend. The aims of this study to identify the phenotype of NTM-positive individuals with bronchiectasis. METHODS: A retrospective single-center observational study was conducted in adult patients with bronchiectasis who underwent bronchoscopy in 2007-2020. Clinical, laboratory, pulmonary function, and radiological data were compared between patients with a positive or negative NTM culture. RESULTS: Compared to the NTM-negative group (n=677), the NTM-positive group (n=94) was characterized (P ≤0.05 for all) by older age, greater proportion of females, and higher rates of gastroesophageal reflux disease and muco-active medication use; lower body mass index, serum albumin level, and lymphocyte and eosinophil counts; lower values of forced expiratory volume in one second, forced vital capacity, and their ratio, and lower diffusing lung capacity for carbon monoxide; higher rates of bronchiectasis in both lungs and upper lobes and higher number of involved lobes; and more exacerbations in the year prior bronchoscopy. On multivariate analysis, older age (OR 1.05, 95% CI 1.02-1.07, P=0.001), lower body mass index (OR 1.16, 95% CI 1.16-1.07, P <0.001), and increased number of involved lobes (OR 1.26, 95% CI 1.01-1.44, P=0.04) were associated with NTM infection. CONCLUSIONS: Patients with bronchiectasis and NTM pulmonary infection are more likely to be older and female with more severe clinical, laboratory, pulmonary function, and radiological parameters than those without NTM infection. This phenotype can be used for screening patients with suspected NTM disease.

Diagnosis of pulmonary Scedosporium apiospermum infection from bronchoalveolar lavage fluid by metagenomic next-generation sequencing in an immunocompetent female patient with normal lung structure: a case report and literature review.

BACKGROUND: Scedosporium apiospermum (S. apiospermum) belongs to the asexual form of Pseudallescheria boydii and is widely distributed in various environments. S. apiospermum is the most common cause of pulmonary infection; however, invasive diseases are usually limited to patients with immunodeficiency. CASE PRESENTATION: A 54-year-old Chinese non-smoker female patient with normal lung structure and function was diagnosed with pulmonary S. apiospermum infection by metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF). The patient was admitted to the hospital after experiencing intermittent right chest pain for 8 months. Chest computed tomography revealed a thick-walled cavity in the upper lobe of the right lung with mild soft tissue enhancement. S. apiospermum was detected by the mNGS of BALF, and DNA sequencing reads were 426. Following treatment with voriconazole (300 mg q12h d1; 200 mg q12h d2-d20), there was no improvement in chest imaging, and a thoracoscopic right upper lobectomy was performed. Postoperative pathological results observed silver staining and PAS-positive oval spores in the alveolar septum, bronchiolar wall, and alveolar cavity, and fungal infection was considered. The patient's symptoms improved; the patient continued voriconazole for 2 months after surgery. No signs of radiological progression or recurrence were observed at the 10-month postoperative follow-up. CONCLUSION: This case report indicates that S. apiospermum infection can occur in immunocompetent individuals and that the mNGS of BALF can assist in its diagnosis and treatment. Additionally, the combined therapy of antifungal drugs and surgery exhibits a potent effect on the disease.

Analysis of risk factors and development of predictive model for malnutrition in patients with traumatic brain injury.

Malnutrition is a highly prevalent complication in patients with traumatic brain injury (TBI), and it is closely related to the prognosis of patients. Accurate identification of patients at high risk of malnutrition is essential. Therefore, we analyzed the risk factors of malnutrition in patients with TBI and developed a model to predict the risk of malnutrition. A retrospective collection of 345 patients with TBI, and they were divided into malnutrition and comparison groups according to the occurrence of malnutrition. Univariate correlation and multifactor logistic regression analyses were performed to determine patients' malnutrition risk factors. We used univariate and logistic regression (forward stepwise method) analyses to identify significant predictors associated with malnutrition in patients with TBI and developed a predictive model for malnutrition prediction. The model's discrimination, calibration, and clinical utility were evaluated using the receiver operating characteristic (ROC) curve, calibration plots, and decision curve analysis (DCA). A total of 216 patients (62.6%) developed malnutrition. Multifactorial logistic regression analysis showed that pulmonary infection, urinary tract infection, dysphagia, application of NGT, GCS score ≤ 8, and low ADL score were independent risk factors for malnutrition in patients with TBI (P < 0.05). The area under the curve of the model was 0.947. Calibration plots showed good discrimination of model calibration. DCA showed that the column line plot models were all clinically meaningful when nutritional interventions were performed over a considerable range of threshold probabilities (0-0.98). Malnutrition is widespread in patients with TBI, and the nomogram is a good predictor of whether patients develop malnutrition.

Risk factors for pulmonary infection in patients with non-small cell lung cancer: a Meta-analysis.

BACKGROUND AND OBJECTIVES: The aim of this study is to assess and examine the risk variables associated with pulmonary infections in non-small cell lung cancer (NSCLC) and to offer evidence-based recommendations for clinical prophylaxis. METHODS: Up to December 2023, database such as CNKI, Wanfang, VIP Chinese Science and Technology Journals, Chinese Biomedical, Pubmed, Web of science, and the Cochrane library were searched in order to find randomized controlled trials pertaining to non-small cell lung cancer complicated by pulmonary infection. The NOS scale was utilized to assess the quality of the included research, and the Q test findings were utilized to ascertain the degree of heterogeneity among the studies. RESULTS: After retrieving 957 studies in total, 10 literatures were ultimately included for additional analysis. Diabetes mellitus [OR, 2.89; 95% CI: 1.85-4.52; P < 0.00001)] hypoalbuminemia, radiotherapy [OR, 0.43; 95% CI: 1.89-4.07; P < 0.00001], and surgical duration exceeding 180 min [OR,1.10 (1.10 ~ 5.38); P = 0.03] were found to be risk factors for lung infection. Nevertheless, in NSCLC patients, pulmonary infection was not significantly correlated with factors such as age [OR, -0.16 (-0.96 ~ 0.64); P = 0.69], sex [OR, 1.08 (0.77 ~ 1.51); P = 0.66], smoking [OR, 1.10 (0.61 ~ 2.00); P = 0.75], adenocarcinoma [OR,1.10 (0.55 ~ 2.22); P = 0.79], OR, 1.08; 95% CI: 0.77-1.51; P = 0.66], TNMIII-IV stages [OR, 1.62; 95% CI: 0.96-2.75; P = 0.07], and hypertension [1.01(0.76 ~ 1.34); P = 0.94]. CONCLUSION: Diabetes mellitus, radiation therapy, and longer than 180-minute surgeries are risk factors for lung infection in NSCLC patients. The incidence of lung infection can be reduced by quickly identifying these risk factors and putting preventive measures in place.

Comparison of the effect between cefazolin/cefuroxime and broad-spectrum antibiotics in preventing post-operative pulmonary infections for smoking patients receiving video-assisted thoracoscopic lung surgery: a propensity score-matched retrospective cohort study.

BACKGROUND: The selection of prophylactic antibiotics for preventing post-operative pulmonary infections in smoking patients undergoing video-assisted thoracoscopic lung surgery (VATLS) is not clear. METHODS: In this retrospective cohort study, the outcomes of 572 smoking patients undergoing VATLS with prophylactic cefazolin/cefuroxime or other antibiotics were analyzed. Patients were classified as cefazolin/cefuroxime group and the control group. A 1:1 propensity score matching was also performed. RESULTS: The primary outcome of the incidence of post-operative pulmonary infection did not differ significantly between the two groups (23.7% vs 30.5%, RR = 0.777, 95%CI 0.564 ~ 1.070 p = 0.113). Similarly, secondary outcomes including the incidence of post-operative fever, the white blood cell count and neutrophils on the 3rd day after the surgery, and time for blood routine test recovery were all found without significant difference between the two groups. In the multivariate logistic regression model, no association was found between prophylactic use of cefazolin/cefuroxime and post-operative pulmonary infections after controlling other possible confounding factors (OR = 0.685, 95%CI 0.441 ~ 1.065, p = 0.093). CONCLUSIONS: Prophylactic use of cefazolin/cefuroxime was not associated with more adverse clinical outcomes among smoking populations undergoing VATLS when compared with broad-spectrum antibiotics and the two drugs are still feasible for peri-operative prophylactic use for smoking population before the surgery.

A rare case of a hard-to-heal ulcer caused by pulmonary Nocardia infection.

DECLARATION OF INTEREST: The authors have no conflicts of interest.

Uncovering the Unseen: Bordetella hinzii Emerges in a Lung Transplant Recipient.

Bordetella hinzii (B. hinzii), a Gram-negative bacillus commonly associated with respiratory infections in animals, has garnered attention for its sporadic cases in humans, particularly in immunocompromised individuals. Despite its opportunistic nature, there remains limited understanding regarding its pathogenicity, diagnostic challenges, and optimal treatment strategies, especially in the context of immunosuppression. Herein, we present the first documented case of acute bronchitis caused by B. hinzii in an immunocompromised patient following double-lung transplantation. The patient, a former smoker with sarcoidosis stage IV, underwent transplant surgery and subsequently developed a febrile episode, leading to the identification of B. hinzii in broncho-alveolar lavage samples. Antimicrobial susceptibility testing revealed resistance to multiple antibiotics, necessitating tailored treatment adjustments. Our case underscores the importance of heightened awareness among clinicians regarding B. hinzii infections and the imperative for further research to elucidate its epidemiology and optimal management strategies, particularly in immunocompromised populations.

[Relationship between the lung ultrasound and the clinical severity of the patient with seasonal flu]. / Lien entre l'aspect échographique du poumon et la sévérité́ clinique du patient atteint d'une grippe saisonnière.

INTRODUCTION: The seasonal flu is a very important reason for consultation every winter. Symptoms can quickly progress to severe pneumonia. Currently, few tools exist to assess the clinical severity of patients. The aim of this study is to demonstrate the role of lung ultrasound as a marker of severity in patients with influenza. METHODS: 79 patients who arrived at the emergency department with flu-like symptoms were included. A pulmonary ultrasound looking for an interstitial syndrome or consolidation was performed. The qSOFA, the SOFA, the saturation, the PaO2/FiO2 ratio, the oxygen needs, the destination of the patient made it possible to establish the seriousness of the pathology of the patient. Ultrasound was then compared to these different tools. RESULTS: The more the ultrasound became pathological, the more we observed a proportion of qSOFA (p = 0.001) and pathological SOFA (p = 0.009). Most patients with acute respiratory distress syndrome have pathological ultrasound (p < 0.001). The average admission saturation is 89.2 % in the "pathological ultrasound" group compared to 95.8 % in the "normal ultrasound" group (p < 0.001). Patients who required invasive therapies had pathological ultrasound (p < 0.001). Of the 28 patients with pathological ultrasound, 24 required hospitalization (p < 0.001). CONCLUSION: Lung ultrasound is a major asset for assessing the severity of the patient with seasonal flu. In addition, ultrasound allows better monitoring of the patient by being able to influence the destination of the latter towards a return home or monitoring in intensive care.

INTRODUCTION: La grippe saisonnière représente chaque hiver un motif de consultation très important. La symptomatologie peut rapidement évoluer vers une pneumonie sévère. Actuellement, peu d'outils existent pour évaluer la sévérité clinique des patients. Le but de cette étude est de démontrer le rôle de l'échographie pulmonaire comme marqueur de sévérité́ chez les patients atteints d'une grippe. Méthodes : L'étude a comporté 79 patients arrivés aux urgences pour grippe. Une échographie pulmonaire a été réalisée à la recherche d'un syndrome interstitiel ou d'une consolidation. Le qSOFA, le SOFA, la saturation, le rapport PaO2/FiO2, les besoins en oxygène, la destination du patient ont permis d'établir la gravité de la pathologie du patient. L'échographie a alors été comparée à ces différents outils. Résultats : Plus l'échographie devient pathologique, plus on observe une proportion de qSOFA (p = 0,001) et de SOFA pathologiques (p = 0,009). La majorité́ des patients ayant un syndrome de détresse respiratoire aiguë ont une échographie pathologique (p < 0,001). La moyenne des saturations d'admission est de 89,2 % dans le groupe «échographie pathologique¼ contre 95,8 % dans le groupe «échographie normale¼ (p < 0,001). Les patients ayant eu recours à des thérapies invasives ont une échographie pathologique (p < 0,001). Sur les 28 patients ayant une échographie pathologique, 24 ont nécessité́ une hospitalisation (p < 0,001). CONCLUSION: L'échographie pulmonaire est un atout majeur pour l'évaluation de la sévérité du patient atteint d'une grippe saisonnière. De plus, l'échographie permet une meilleure surveillance du patient en pouvant influencer la destination de celui-ci vers un retour à̀ domicile ou une surveillance aux soins intensifs.

Latest Advances in the Application of Humanized Mouse Model for Staphylococcus aureus.

Staphylococcus aureus (S. aureus) is an important pathogen for humans and can cause a wide range of diseases, from mild skin infections, severe osteomyelitis to fatal pneumonia, sepsis, and septicemia. The mouse models have greatly facilitated the development of S. aureus studies. However, due to the substantial differences in immune system between mice and humans, the conventional mouse studies are not predictive of success in humans, in which case humanized mice may overcome this limitation to some extent. Humanized mice can be used to study the human-specific virulence factors produced by S. aureus and the mechanisms by which S. aureus interacts with humans. This review outlined the latest advances in humanized mouse models used in S. aureus studies.

Construction of a prediction model for pulmonary infection and its risk factors in Intensive Care Unit patients.

Objective: To identify independent risk factors of pulmonary infection in intensive care unit (ICU) patients, and to construct a prediction model. Methods: Medical data of 398 patients treated in the ICU of Jiaxing Hospital of Traditional Chinese Medicine from January 2019 to January 2023 were analyzed. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for pulmonary infection in ICU patients. R software was used to construct a nomogram prediction model, and the prediction model was internally validated using computer simulation bootstrap method. Predictive value of the model was analyzed using the receiver operating characteristic (ROC) curve. Results: A total of 97 ICU patients (24.37%) developed pulmonary infection. Age, ICU stay time, invasive operation, diabetes, duration of mechanical ventilation, and state of consciousness were all identified as risk factors for pulmonary infection. The calibration curve of the constructed nomogram prediction model showed a good consistency between the predicted value of the model and the actual observed value. ROC curve analysis showed that the area under the curve (AUC) of the model was 0.784 (95% CI: 0.731-0.837), indicating a certain predictive value. Conclusions: Age, length of stay in ICU, invasive operation, diabetes, duration of mechanical ventilation, and state of consciousness are risk factors for pulmonary infection in ICU patients. The nomogram prediction model constructed based on the above risk factors has shown a good predictive value.

Pathogenesis of Achromobacter xylosoxidans respiratory infections: colonization, persistence, and transcriptome profiling in synthetic cystic fibrosis sputum medium.

Cystic fibrosis (CF) is a genetic disease affecting epithelial ion transport, resulting in thickened mucus and impaired mucociliary clearance. Persons with CF (pwCF) experience life-long infections of the respiratory mucosa caused by a diverse array of opportunists, which are leading causes of morbidity and mortality. In recent years, there has been increased appreciation for the range and diversity of microbes causing CF-related respiratory infections. The introduction of new therapeutics and improved detection methodology has revealed CF-related opportunists such as Achromobacter xylosoxidans (Ax). Ax is a Gram-negative bacterial species which is widely distributed in environmental sources and has been increasingly observed in sputa and other samples from pwCF, typically in patients in later stages of CF disease. In this study, we characterized CF clinical isolates of Ax and tested colonization and persistence of Ax in respiratory infection using immortalized human CF respiratory epithelial cells and BALB/c mice. Genomic analyses of clinical Ax isolates showed homologs for factors including flagellar synthesis, antibiotic resistance, and toxin secretion systems. Ax isolates adhered to polarized cultures of CFBE41o- human immortalized CF bronchial epithelial cells and caused significant cytotoxicity and depolarization of cell layers. Ax colonized and persisted in mouse lungs for up to 72 h post infection, with inflammatory consequences that include increased neutrophil influx in the lung, lung damage, cytokine production, and mortality. We also identified genes that are differentially expressed in synthetic CF sputum media. Based on these results, we conclude that Ax is an opportunistic pathogen of significance in CF.

Pulmonary infection in patients with severe fever with thrombocytopenia syndrome: A multicentre observational study.

Co-infection in patients with severe fever with thrombocytopenia syndrome (SFTS) has been reported, posing a serious threat to survival and treatment. We aimed to systematically investigate the SFTS associated pulmonary infection, particularly invasive pulmonary fungal infection (IPFI). During April 2019 to October 2021, we conducted a multicentre observational study on adult hospitalized patients confirmed with SFTS from three tertiary hospital in central China. Demographic, clinical and laboratory data of patients were collected and re-assessed. A total of 443 patients (51.7% were male sex) were included for analysis with median age of 65-year-old. Among them, 190 (42.9%) patients met the criteria for pulmonary infection. Pulmonary infection was associated with shorter survival time (p < 0.0001 by log-rank test), and adjusted hazard ratio was 1.729 [95% confidence interval, 1.076-2.780] (p = 0.024). Age (odds ratio (OR) 1.040 [1.019-1.062], p < 0.001), time from onset to admission (OR 1.163 [1.070-1.264], p < 0.001), having severe status (OR 3.166 [2.020-4.962], p < 0.001) and symptoms of skin change (OR 2.361 [1.049-5.316], p < 0.001) at admission and receiving intravenous immunoglobin (OR 2.185 [1.337-3.569], p = 0.002) were independent risk factors for the occurrence of pulmonary infection. A total of 70 (15.8%) patients were defined as IPFI. Multivariate analysis showed that time from onset to admission (OR 1.117 [1.016-1.229], p = 0.022), severe status (OR 5.737 [3.054-10.779], p < 0.001), having smoking history (OR 3.178 [1.251-8.070], p = 0.015) and autoimmunity disease (OR 7.855 [1.632-37.796], p = 0.010), receiving intravenous immunoglobin (OR 3.270 [1.424-7.508], p = 0.005) were independent risk factors for the occurrence of IPFI. In SFTS patients with pulmonary infection, white blood count <2.09 × 109 per L (OR 11.064 [3.708-33.012], p < 0.001) and CD3+ CD4+ T cell count <104.0 per µL (OR 10.429 [3.395-32.038], p < 0.001) could independently predict IPFI. This study showed the high prevalence and poor outcomes of pulmonary infection and IPFI in patients with SFTS. These findings highlighted the need for active surveillance of fungal pathogens and early antifungal treatment in patients with SFTS.

Predictors and prognosis of tracheostomy in relapsing polychondritis.

OBJECTIVE: Airway obstruction can occur in patients with relapsing polychondritis (RP) with laryngeal involvement, occasionally requiring tracheostomy to avoid serious complications. Herein, we assessed the risk factors for tracheostomy and developed a risk prediction model. METHODS: Clinical characteristics of patients with RP, with and without tracheostomy, were compared using multivariate logistic regression analysis to identify risk factors. A nomogram was developed to predict the population at risk of requiring tracheostomy. RESULTS: In total, 232 patients with RP were reviewed, of whom 146 had laryngeal involvement. Among them, 21 underwent a tracheostomy. Multivariate logistic analysis identified ages ≤ 25 or ≥ 65 (p< 0.001, OR: 24.584, 95% CI: 5.310-113.815), laryngotracheal oedema (p< 0.001, OR: 26.685, 95% CI: 4.208-169.228), and pulmonary infection (p= 0.001, OR: 18.834, 95% CI: 3.172-111.936) as independent risk factors for tracheostomy. A nomogram with a C-index of 0.936 (95% CI: 0.894-0.977) was established based on the multivariate analysis. Internal bootstrap resampling (1000 repetitions) confirmed sufficient discriminatory power with a C-index of 0.926. Decision curve analysis indicated a superior net benefit of the nomogram. Tracheostomy was associated with a significant increase in the in-hospital mortality rate (p= 0.021), but it did not affect the long-term survival rate (p= 0.706). CONCLUSION: Tracheostomy is associated with an increase in the short-term mortality rate but does not affect the long-term survival rate. The nomogram developed in this study may help identify patients at high risk for tracheostomy and aid in clinical decision-making.

Positive association between stress hyperglycemia ratio and pulmonary infection in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention.

BACKGROUND: Previous studies have shown that the stress hyperglycemia ratio (SHR), a parameter of relative stress-induced hyperglycemia, is an excellent predictive factor for all-cause mortality and major adverse cardiovascular events (MACEs) among patients with ST-segment elevation myocardial infarction (STEMI). However, its association with pulmonary infection in patients with STEMI during hospitalization remains unclear. METHODS: Patients with STEMI undergoing percutaneous coronary intervention (PCI) were consecutively enrolled from 2010 to 2020. The primary endpoint was the occurrence of pulmonary infection during hospitalization, and the secondary endpoint was in-hospital MACEs, composed of all-cause mortality, stroke, target vessel revascularization, or recurrent myocardial infarction. RESULTS: A total of 2,841 patients were finally included, with 323 (11.4%) developing pulmonary infection and 165 (5.8%) developing in-hospital MACEs. The patients were divided into three groups according to SHR tertiles. A higher SHR was associated with a higher rate of pulmonary infection during hospitalization (8.1%, 9.9%, and 18.0%, P < 0.001) and in-hospital MACEs (3.7%, 5.1%, and 8.6%, P < 0.001). Multivariate logistic regression analysis demonstrated that SHR was significantly associated with the risk of pulmonary infection during hospitalization (odds ratio [OR] = 1.46, 95% confidence interval [CI] 1.06-2.02, P = 0.021) and in-hospital MACEs (OR = 1.67, 95% CI 1.17-2.39, P = 0.005) after adjusting for potential confounding factors. The cubic spline models demonstrated no significant non-linear relationship between SHR and pulmonary infection (P = 0.210) and MACEs (P = 0.743). In receiver operating characteristic curve, the best cutoff value of SHR for pulmonary infection was 1.073. CONCLUSIONS: The SHR is independently associated with the risk of pulmonary infection during hospitalization and in-hospital MACEs for patients with STEMI undergoing PCI.

NLRP3 inflammasome activation contributes to fungal clearance and lung injury during Talaromyces marneffei infection.

The increased levels of IL-1ß and IL-18 cytokines have been associated with the severity of sepsis and outcomes of patients infected with Talaromyces marneffei. Previous studies have suggested that NLRP3 plays an important role in caspase-1 activated secretion of IL-1ß and IL-18 in fungal-infected macrophages. In the present study, the role of the NLRP3 inflammasome in talaromycosis is investigated in an in vitro assay and in vivo with a mice systemic infection model. We found that the NLRP3 inflammasome pathway in infected mice is activated along with increased production of IL-1ß. Such an activation of the NLRP3 inflammasome is also observed in either mice or human macrophages challenged with T. marneffei conidia. Our results indicate that IL-1ß release by infected macrophages is NLRP3 inflammasome-dependent and NLRP3 contributes to death of mice at the early stage of pulmonary infection. Moreover, a greater number of MPO-positive cells are found in the lungs of infected Nlrp3-/- mice and WT mice with reduced LDH levels, especially at the last stage of infection. Therefore, we conclude that the NLRP3 Inflammasome activation is important for fungal clearance, neutrophil recruitment and lung injury during T. marneffei Infection.

Previous pulmonary infection impacts thoracoscopic procedure outcomes in patients with congenital lung malformations: a retrospective cohort study.

BACKGROUND AND OBJECTIVES: Patients with congenital lung malformations (CLMs) are at high risk for developing pulmonary infection. Nonetheless, prophylactic surgical excision of asymptomatic CLMs is controversial and often delayed to symptoms occurring out of concern for potential operative risks. This study aims to evaluate the impact of previous pulmonary infection on the outcome of thoracoscopic procedures in CLMs patients. METHODS: This was a retrospective cohort study of CLMs patients who received an elective operation at a tertiary care center from 2015 to 2019. Patients were divided into pulmonary infection (PI) or non-infection of pulmonary (NPI) groups according to the history of pulmonary infection. Propensity score matching was used to minimize the bias between groups. The primary outcome was conversion to thoracotomy. Postoperative outcomes were compared between patients with and without PI. RESULTS: We identified 464 patients, of whom 101 had a history of PI. Propensity score matching yielded a well-balanced cohort of 174 patients. PI was associated with higher conversion to thoracotomy (adjusted odds ratio = 8.7, 95% confidence interval, CI, 1.1-71.2, p = 0.039), blood loss (p = 0.044), and longer operative time (p < 0.001), chest tube placement time (p < 0.001), length of stay (p < 0.001), and postsurgical length of stay (p < 0.001). CONCLUSIONS: Elective operation in CLMs patients with a history of PI was associated with an increased risk of conversion to thoracotomy, operative time, blood loss, chest tube placement time, length of stay, and postsurgical length of stay. Elective thoracoscopic procedures in asymptomatic CLMs patients are safe and effective, and earlier surgical intervention may be warranted.

Propagation of an idealized infection in an airway tree, consequences of the inflammation on the oxygen transfer to blood.

A mathematical model of infection, inflammation and immune response in an idealized bronchial tree is developed. This work is based on a model from the literature that is extended to account for the propagation dynamics of an infection between the airways. The inflammation affects the size of the airways, the air flows distribution in the airway tree, and, consequently, the oxygen transfers to blood. We test different infections outcomes and propagation speed. In the hypotheses of our model, the inflammation can reduce notably and sometimes drastically the oxygen flow to blood. Our model predicts how the air flows and oxygen exchanges reorganize in the tree during an infection. Our results highlight the links between the localization of the infection and the amplitude of the loss of oxygen flow to blood. We show that a compensation phenomena due to the reorganization of the flow exists, but that it remains marginal unless the power produced the ventilation muscles is increased. Our model forms a first step towards a better understanding of the dynamics of bronchial infections.

Nocardia pulmonis sp. nov., an actinomycete isolated from a patient with pulmonary infection.

A novel bacterial strain, CDC141T, was isolated from sputum samples of a patient with pulmonary infection in Hainan Province, PR China. We performed a polyphasic study to assess the taxonomic position of the new species. Based on the results of 16S rRNA gene sequence analyses, strain CDC141T belonged to the genus Nocardia with the highest sequence similarity to Nocardia nova NBRC 15556T (98.84 %) and Nocardia macrotermitis RB20T (98.54 %). The dapb1 gene sequence-based phylogenetic and phylogenomic trees further showed that the novel strain was clustered in a distinct clade adjacent to Nocardia pseudobrasiliensis DSM 44290T. The DNA G+C content of strain CDC141T was 68.57 mol%. The genomic diversity analysis revealed low average nucleotide identity and in silico DNA‒DNA hybridization values (<84.7 and <28.9 %, respectively) with its closest relative. Growth occurred at 20-40 °C, pH 6.0-9.0 and with NaCl concentrations of 0.5-2.5 % (w/v). The main fatty acids of strain CDC141T were C16 : 0, C18 : 0 10-methyl, TBSA, C16 : 1 ω6c/C16 : 1 ω7c, C18 : 1 ω9c, C18 : 0, C17 : 1 iso I/anteiso B and C17 : 0. The polar lipid profile was dominated by diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, unidentified glycolipids, unidentified phospholipids and unidentified lipids. MK8 (H4ω-cycl) and MK8 (H4) were the major respiratory quinones. These characteristics were consistent with the typical chemotaxonomic properties of members of the genus Nocardia. Based on the results of phenotypic and genetic analyses, strain CDC141T was identified as representing a new species of the genus Nocardia, with the proposed name Nocardia pulmonis sp. nov. (CDC141T=JCM 34955T=GDMCC 4.207T).