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Cost-effective molecular diagnostic techniques for bacterial pneumonia are limited. We designed primers for 13 bacteria, performed multiplex nucleic acid detection through fragment analysis to obtain pathogen identification results, and established a multiplex PCR-capillary electrophoresis (MPCE) method, which can simultaneously detect 13 pathogens associated with bacterial pneumonia. The sensitivity, specificity, and reproducibility of the MPCE assay were tested, and 420 clinical samples were used to assess the clinical detection ability of MPCE, with the culture method used as a reference. Samples with inconsistent results detected by the two methods were sent for Sanger sequencing. The minimum detection limit of MPCE for 13 bacteria was 6.0 × 10 3 cfu/mL~2.0 × 10 6 cfu/mL. No cross-reactivity was observed with other pathogens. The percentage of agreement for reproducibility analysis reached 100%. For the 420 sputum samples, when the culture method was used as the reference, the sensitivity of MPCE to 13 bacteria ranged from 80% to 100%. The specificity for 13 bacteria ranged from 67.1% to 100%. The percentage of agreement between the MPCE and the culture method ranged from 69.7% to 100%. There was no statistically significant difference ( P > 0.05) in the detection of Escherichia coli , Enterobacter cloacae complex , Staphylococcus aureus , methicillin-resistant S. aureus, Streptococcus pyogenes , Moraxella catarrhalis , or Legionella pneumophila between the MPCE and the culture method. Clinical samples with negative cultures but positive MPCE results were validated by Sanger sequencing, and the results were consistent with those of MPCE. The MPCE method has high sensitivity and specificity for bacterial pneumonia, enabling the simultaneous and rapid detection of multiple pathogens. It is cost-effective and has potential for clinical application., Importance: This study successfully established a multiplex PCR-capillary electrophoresis detection system that can simultaneously detect 13 pathogens through a single detection method, significantly improving clinical efficiency. It is cost-effective and has potential for clinical application., Competing Interests: The authors declare no conflict of interest.

Background: COVID-19 began in December 2019, rapidly spreading worldwide. China implemented a dynamic zero-COVID strategy and strict control measures after the outbreak. However, Guangzhou city ended closed-off management by the end of November 2022, leading to exposure to SARS-CoV-2. Despite most hospitalized patients being infected or co-infected with SARS-CoV-2, some remained uninfected. We report two cases of bacterial pneumonia with elevated globulin levels not infected with SARS-CoV-2, aiming to identify protection factors of SARS-CoV-2 infection and provide a scientific basis for SARS-CoV-2 prevention., Case Presentation: Case 1, a 92-year-old male, admitted on October 21, 2022, developed worsening cough and sputum after aspiration, diagnosed with bacterial pneumonia with Pseudomonas aeruginosa, Escherichia coli (CRE) and carbapenem-resistant Acinetobacter baumannii (CRAB) infections. He was treated with imipenem anti-infective therapy and mechanical ventilation, then switched to a combination of meropenem, voriconazole and amikacin anti-infective therapy due to recurrent infections and septic shock, and died of sepsis on 8 January 2023. Case 2 is an 82-year-old male admitted on 30 September 2022, with recurrent cough, sputum, and shortness of breath, diagnosed with bacterial pneumonia with carbapenem-resistant Klebsiella pneumoniae (CRKP) and Mycobacterium pneumoniae infections. He was treated with ventilator-assisted ventilation, meropenem, amikacin, tigecycline and mucomycin nebulization and discharged with improvement on 26 October. He was readmitted on 21 November 2022 and diagnosed with bacterial pneumonia. He was treated with cefoperazone sulbactam, amikacin, meropenem and fluconazole and discharged on 31 December. Neither patient was infected with SARS-CoV-2 during hospitalization. Notably, their globulin levels were elevated before SARS-CoV-2 exposure, gradually decreasing afterward., Conclusions: Patients with bacterial pneumonia with high globulin levels likely have large amounts of immunoglobulin, and that immunoglobulin cross-reactivity causes this protein to be involved in clearing SARS-CoV-2 and preventing infection. Therefore, bacterial pneumonia patients with high globulin levels included in this study were not infected with SARS-CoV-2. After exposure to SARS-CoV-2, the amount of globulin in the patient's body was reduced because it was used to clear SARS-CoV-2. The results of this study are expected to provide a theoretical basis for the study of the mechanism of prevention and treatment of SARS-CoV-2 infection., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhong, Lin, Long, Liao, Sun, Yang, Zhang, Huang, Wang and Yang.)

Rationale: Shewanella algae are Gram-negative bacteria that are widely found in aquatic habitats and rarely cause lung infections in inland areas., Patient Concerns: Cough with light-yellow phlegm for 2 weeks., Diagnoses: The final diagnosis was bacterial pneumonia., Interventions: The patient was treated with ceftazidime (2 g, every 12 h) for 1 week., Outcomes: The patient's lung infection improved and he was discharged., Lessons: This case highlights a rare occurrence of lung infection caused by Shewanella algae in elderly Tibetan men residing in non-marine environments., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Pneumonia caused by Legionella longbeachae, transmitted through contaminated soil, is very rare in Japan. A 70-year-old man with severe respiratory failure was admitted to our hospital and underwent multidisciplinary procedures. Although a urinary antigen test was negative for Legionella, he was clinically diagnosed with legionellosis and administered levofloxacin. His condition subsequently improved. Thereafter, sputum culture detected L. longbeachae. Because the DNA of L. longbeachae was detected in the gardening soil, it is suspected source of infection. Therefore, it is important to suspect legionellosis based on clinical information, even if a urine antigen test is negative.

Introduction: Hospital-acquired pneumonia (HAP) represents a significant cause of mortality among critically ill patients admitted to Intensive Care Units (ICUs). Timely and precise diagnosis is imperative to enhance therapeutic efficacy and patient outcomes. However, the diagnostic process is challenged by test limitations and a wide-ranging list of differential diagnoses, particularly in patients exhibiting escalating oxygen requirements, leukocytosis, and increased secretions., Areas Covered: This narrative review aims to update diagnostic modalities, facilitating the prompt identification of nosocomial pneumonia while guiding, developing, and assessing therapeutic interventions. A comprehensive literature review was conducted utilizing the MEDLINE/PubMed database from 2013 to April 2024., Expert Opinion: An integrated approach that integrates clinical, microbiological, and imaging tools is paramount. Progress in diagnostic techniques, including novel molecular methods, the expanding utilization and accuracy of bedside ultrasound, and the emergence of Artificial Intelligence, coupled with an improved comprehension of lung microbiota and host-pathogen interactions, continues to enhance our capability to accurately and swiftly identify HAP and its causative agents. This advancement enables the refinement of treatment strategies and facilitates the implementation of precision medicine approaches.

This study aimed to investigate the expression and significance of serum procalcitonin (PCT), leukotriene B4 (LTB4), Serum amyloid A (SAA), and C-reactive protein (CRP) in children with different types of pneumonia caused by different pathogenic infections. One hundred and one children with pneumonia admitted to The Fifth People Hospital of Zhuhai from July 2019 to June 2020 were enrolled and divided into 38 cases in the bacterial group, 30 cases in the mycoplasma group, and 33 cases in the virus group according to the different types of pathogens. The patients were divided into 42 cases in the noncritical group, 33 cases in the critical group, and 26 cases in the very critical group according to the pediatric clinical illness score (PCIS), and 30 healthy children were selected as the control group during the same period. Comparison of serum PCT, SAA: bacterial group > mycoplasma group > viral group > control group with significant differences (P < .05). Receiver operator characteristic (ROC) analysis showed that the area under the curves (AUCs) of serum PCT, LTB4, SAA, and CRP for the diagnosis of bacterial pneumonia were 1.000, 0.531, 0.969, and 0.833, respectively, and the AUCs for the diagnosis of mycoplasma pneumonia were 0.653, 0.609, 0.547, and 0.652, respectively, and the AUCs for the diagnosis of viral pneumonia were 0.888, 0.570, 0.955, and 1.000, respectively. Comparison of serum PCT, LTB4, SAA: very critical group > critical group > noncritical group > control group, with significant differences (P < .05). Serum PCT, LTB4, and SAA were negatively correlated with PCIS score by Pearson analysis (P < .05). Serum PCT and SAA showed diagnostic value for bacterial pneumonia, and serum SAA and CRP showed diagnostic value for viral pneumonia; serum PCT, LTB4, and SAA correlate with severity of disease and show higher expression with worsening of the condition., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Neurogenic inflammation is involved in the development and progression of respiratory inflammatory diseases. However, its role in community-acquired pneumonia (CAP) remains unclear. We therefore aimed to investigate plasma levels of neurogenic inflammation-related neuropeptides, calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY), and procalcitonin (PCT) in pediatric patients with CAP and to assess their diagnostic value in viral and bacterial/mixed pneumonia. A total of 124 pediatric patients with CAP (1 month-18 years old) and 56 healthy children of similar ages were prospectively enrolled. The patients were classified as viral (n = 99) and bacterial/mixed (n = 25) pneumonia. Plasma levels of the peptides were quantified by ELISA. ROC analysis was performed to evaluate possible diagnostic value of the peptides. While plasma levels of CGRP, VIP and PCT were significantly higher in patients with CAP than in the control group, respectively, NPY levels were significantly lower. Moreover, plasma levels of all neuropeptides and PCT were significantly higher in bacterial pneumonia patients compared to viral pneumonia patients. ROC analysis revealed that CGRP, SP and NPY had a diagnostic value in distinguishing viral and bacterial/mixed pneumonia., Conclusions: Our findings suggest that these neuropeptides may be implicated in pediatric CAP. CGRP, SP and NPY together may be a promising candidate in distinguishing viral and bacterial/mixed pneumonia, however, for this, further studies are needed., What Is Known: • Neurogenic inflammation contributes to the development and progression of respiratory inflammatory diseases such as chronic obstructive pulmonary disease and bronchial asthma., What Is New: • Plasma levels of neurogenic inflammation related neuropeptides calcitonin gene-related peptide, substance P, vasoactive intestinal peptide and neuropeptide Y are changed in pediatric community-acquired pneumonia. Calcitonin gene-related peptide, substance P and neuropeptide Y are promising candidates in distinguishing viral and bacterial/mixed pneumonia., (© 2024. The Author(s).)

Background: Post infectious glomerulonephritis is the most common glomerulopathy in children, occurring several weeks after nephritogenic streptococcal throat or skin infection. Reports of acute glomerulonephritis (AGN) occurring during active bacterial pneumonia in children are rare. The aim of this study was to evaluate the incidence of AGN concurrent with bacterial pneumonia in children., Methods: We reviewed records of all children admitted with a diagnosis of pneumonia to the pediatric department in a single tertiary medical center between January 2015 and April 2023. Patients with bacterial pneumonia and concurrent glomerulonephritis were included., Results: Eleven (0.98%) of 1,123 patients with bacterial pneumonia had concurrent AGN. All were males with a median age of 2.7 years (range 1-13). Mean time from bacterial pneumonia onset to acute glomerulonephritis symptoms was 2.7 ± 1.5 days. Five (45%) patients had evidence of pneumococcal infection. Hypertension was found in 10 (91%) patients. Mean trough eGFR was 43.5 ± 21.4 ml/min/1.73 m 2 (range 11-73). Ten patients (91%) had low C3 levels. Median urinary protein-to-creatinine ratio was 2.5 mg/mg (IQR 2.15-14.75). All patients fully recovered. Microscopic hematuria was the last finding to normalize after a median of 29.5 days (IQR 17.25-38)., Conclusion: AGN during bacterial pneumonia may be more frequent than previously recognized. Kidney prognosis was excellent in all patients. Prospective studies are needed to evaluate the impact of this condition., (© 2023. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Objectives: The objective of this study was to evaluate the early predictors of bacterial pneumonia infection in children with congenital heart disease (CHD) after cardiopulmonary bypass (CPB)., Design: Retrospective study., Setting: A freestanding tertiary paediatric hospital in China., Participants: Patients admitted to the hospital due to CHD who underwent open-heart surgery., Outcome Measures: We retrospectively reviewed and analysed data from 1622 patients with CHD after CPB from June 2018 to December 2020 at the Children's Hospital of Nanjing Medical University. Enrolled patients were assigned to an infection group or a non-infection group according to the presence of postoperative bacterial pneumonia infection, and the differences in clinical indicators were compared. Potential predictors were analysed by multivariate logistic regression analysis and area under the curve (AUC) analysis., Results: Among the 376 patients (23.2%) in the infection group, the three most common bacteria were Streptococcus pneumoniae in 67 patients (17.8%), Escherichia coli in 63 patients (16.8%) and Haemophilus influenzae in 53 patients (14.1%). The infection group exhibited a lower weight (8.0 (6.0-11.5) kg vs 11.0 (7.5-14.5) kg, p<0.001). In the infection group, procalcitonin (PCT) (ng/mL: 4.72 (1.38-9.52) vs 1.28 (0.47-3.74), p<0.001) and C reactive protein (CRP) (mg/L: 21.0 (12.1-32.0) vs 17.0 (10.0-27.0), p<0.001) levels were significantly greater than those in the non-infection group. Binary logistic regression analysis revealed that weight, PCT and CRP were independent risk factors for pulmonary bacterial infection after CPB. The AUCs of weight, PCT, CRP and PCT+CRP for predicting pulmonary bacterial infection after CPB were 0.632 (95% CI 0.600 to 0.664), 0.697 (95% CI 0.667 to 0.727), 0.586 (95% CI 0.554 to 0.618) and 0.694 (95% CI 0.664 to 0.724), respectively, and the cut-off values were ≤10.25 kg, ≥4.25 ng/mL, ≥6.50 mg/L and ≥0.20, respectively. The sensitivities were 69.7%, 54.0%, 93.9% and 70.2%, and the specificities were 53.5%, 77.7%, 19.4% and 59.1%, respectively., Conclusions: In our study, weight, PCT and CRP were found to be independent predictors of pulmonary bacterial infection after CPB. Moreover, PCT was the most specific predictor, and CRP was the most sensitive independent predictor that might be beneficial for the early diagnosis of pulmonary bacterial infection after CPB in patients with CHD., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Community-acquired pneumonia (CAP) is a common disease in children, and its aetiological and clinical diagnosis are challenging for physicians in both private practice and hospitals. Over the past three decades, conjugate vaccines have successfully reduced the burden of the former main causes of CAP, Streptococcus pneumoniae and Haemophilus influenzae type b. Today, viruses are by far the most commonly detected pathogens in children with CAP.  Conclusion: New insights into the aetiology and treatment of CAP in children in recent years have influenced management and are the focus of this review. In addition to reducing diagnostic uncertainty, there is an urgent need to reduce antibiotic overuse and antimicrobial resistance in children with CAP. What is Known: • Conjugate vaccines against Streptococcus pneumoniae and Haemophilus influenzae type b have shifted the epidemiology of childhood CAP to predominantly viral pathogens and Mycoplasma pneumoniae. • Clinical, laboratory, and radiological criteria cannot reliably distinguish between bacterial and viral aetiology in children with CAP. What is New: • Test results and epidemiological data must be carefully interpreted, as no single diagnostic method applied to non-pulmonary specimens has both high sensitivity and high specificity for determining pneumonia aetiology in childhood CAP. • This review provides a simple and pragmatic management algorithm for children with CAP to aid physicians in providing optimal and safe care and reducing antibiotic prescribing., (© 2023. The Author(s).)

Bacterial pneumonia causes significant morbidity and mortality especially in elderly and immunocompromised hosts. Achromobacter xylosoxidans denitrificans pneumonia is very rarely reported. However, the reported cases have been in patients who are either immunocompromised or have bronchiectasis. We hereby present a unique case of Achromobacter xylosoxidans denitrificans pneumonia in an immunocompetent patient with advanced chronic obstructive pulmonary disease (COPD). Our patient is a Caucasian male admitted with shortness of breath, fever and cough. Chest X-ray demonstrated right-sided infiltrates and he was treated with intravenous ceftriaxone and azithromycin. He was discharged home on oral amoxicillin-clavulanate 875-125 mg two times per day for a total of 7 days. Patient returned to emergency room after 5 weeks with persistent symptoms and chest X-ray revealed persistent right-sided infiltrate and sputum culture showed Achromobacter xylosoxidans denitrificans. The patient was started on oral levofloxacin 750 mg one time per day for 2 weeks with resolution of symptoms., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Conventional methods used to determine pneumonia pathogens are characterized by low sensitivity and long turnaround times. Introducing new tests with better parameters in patients at higher risk of infections is highly anticipated. The results of the conventional quantitative culture method (CM) in determining the bacterial etiology of pneumonia were compared with the results of the Pneumonia plus Panel test (PNP; BioFire® Diagnostics, USA) in 79 samples of bronchoalveolar lavage (BAL). Materials were collected from 79 patients with suspected pneumonia treated in an oncologic hospital due to solid tumors. Only 16/79 BAL samples (20.3%) were true positive (TP) for bacterial etiology in CM vs. 27/79 samples (34.2%) true positive in the PNP test. The total agreement between methods of interpreting the result (positive or negative) was 84.8%. The most prevalent pathogens in both methods were Staphylococcus aureus , followed by Escherichia coli, Pseudomonas aeruginosa , and Haemophilus influenzae . The PNP test identified several respiratory pathogens that were not grown in culture. The semiquantitative value reported by the PNP test was higher than that reported by culture. The PNP test vs. combined test (PNP test and CM methods) demonstrated positive predictive value (PPV) and negative predictive value (NPV) values of 100.0% and 98.1%, and the sensitivity and specificity were 96.4% and 100.0%. The PNP test is a good tool for determining the etiology of bacterial pneumonia and may support the care of an oncologic patient. However, further large-sample studies are needed to research in strictly defined groups of oncologic patients., (© 2023 Maria Teresa Szymankiewicz et al., published by Sciendo.)

Objective: To externally validate and update the Feverkids tool clinical prediction model for differentiating bacterial pneumonia and other serious bacterial infections (SBIs) from non-SBI causes of fever in immunocompromised children., Design: International, multicentre, prospective observational study embedded in PErsonalised Risk assessment in Febrile illness to Optimise Real-life Management across the European Union (PERFORM)., Setting: Fifteen teaching hospitals in nine European countries., Participants: Febrile immunocompromised children aged 0-18 years., Methods: The Feverkids clinical prediction model predicted the probability of bacterial pneumonia, other SBI or no SBI. Model discrimination, calibration and diagnostic performance at different risk thresholds were assessed. The model was then re-fitted and updated., Results: Of 558 episodes, 21 had bacterial pneumonia, 104 other SBI and 433 no SBI. Discrimination was 0.83 (95% CI 0.71 to 0.90) for bacterial pneumonia, with moderate calibration and 0.67 (0.61 to 0.72) for other SBIs, with poor calibration. After model re-fitting, discrimination improved to 0.88 (0.79 to 0.96) and 0.71 (0.65 to 0.76) and calibration improved. Predicted risk <1% ruled out bacterial pneumonia with sensitivity 0.95 (0.86 to 1.00) and negative likelihood ratio (LR) 0.09 (0.00 to 0.32). Predicted risk >10% ruled in bacterial pneumonia with specificity 0.91 (0.88 to 0.94) and positive LR 6.51 (3.71 to 10.3). Predicted risk <10% ruled out other SBIs with sensitivity 0.92 (0.87 to 0.97) and negative LR 0.32 (0.13 to 0.57). Predicted risk >30% ruled in other SBIs with specificity 0.89 (0.86 to 0.92) and positive LR 2.86 (1.91 to 4.25)., Conclusion: Discrimination and calibration were good for bacterial pneumonia but poorer for other SBIs. The rule-out thresholds have the potential to reduce unnecessary investigations and antibiotics in this high-risk group., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Community-Acquired Pneumonia (CAP) is the primary cause of hospitalization in the United States and the third leading cause of death in Brazil. The gold standard for diagnosing the etiology of CAP includes blood culture, Gram-stained sputum, and sputum culture. However, these methods have low sensitivity. No studies investigating the etiology of CAP have been conducted in Brazil in the last 20-years, and the empirical choice of antimicrobials is mainly based on the IDSA guidelines. This is the first national study with this aim, and as a result, there's potential for the Brazilian consensus to be impacted and possibly modify its guidelines rather than adhering strictly to the IDSA's recommendations., Methods: The aim of this study is to identify the main microorganisms implicated in CAP by employing a multiplex Polymerase Chain Reaction (mPCR) at the foremost public hospital in Brazil. All patients who were admitted to the emergency department and diagnosed with severe CAP underwent an mPCR panel using nasopharyngeal and oropharyngeal swabs, with the aim of detecting 13 bacterial and 21 viral pathogens., Results: A total of 169 patients were enrolled in the study. The mPCR panel identified an etiological agent in 61.5% of patients, with viruses being the most common (42.01%), led by Rhinovirus, followed by Influenza and Coronavirus (non-SARS-CoV-2). Bacterial agents were identified in 34.91% of patients, with S. pneumoniae being the most common, followed by H. influenzae, M. catarrhalis, and S. aureus. Additionally, we found that the prescription for 92.3% of patients could be modified, with most changes involving de-escalation of antibiotics and antiviral therapy., Conclusion: Our study revealed different etiological causes of CAP than those suggested by the Brazilian guidelines. Using molecular diagnostic tests, we were able to optimize treatment by using fewer antibiotics., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (Copyright © 2023 Sociedade Brasileira de Infectologia. Published by Elsevier España, S.L.U. All rights reserved.)

Background: The aim was to explore the value of combined detection of PCT, CRP, and FIB in differentiating severe pneumonia from viral infection and bacterial infection., Methods: A total of 100 patients with severe pneumonia admitted to Hebei General Hospital from August 2020 to November 2021 were selected as the research objects, including 50 patients with viral pneumonia (as the viral group, n = 50) and 50 patients with bacterial pneumonia (as the bacterial group, n = 50). At the same time, the clinical data of 50 healthy people in the hospital were selected as the healthy group (n = 50). All the subjects in the three groups were tested for PCT, CRP, and FIB. The difference of each index level among the three groups was compared. The diagnostic efficacy of each index for pneumonia was analyzed by drawing receiver operating characteristic curves, and the independent predictors of pneumonia were determined by logistic regression model., Results: There were no statistically significant differences in gender, age, course of disease, body mass index (BMI), and other general data among the three groups (p > 0.05). Compared with the healthy group, the levels of serum PCT, CRP, and FIB in the viral group and the bacterial group were significantly increased, and the levels of serum PCT, CRP, and FIB in the bacterial group were significantly higher than those in the viral group, and the differences were statistically significant (p < 0.05). The positive rates of FIB, CRP, and PCT in bacterial group and viral group were increased in turn, and the differences were statistically significant (p < 0.05), and the positive rates of combined detection in the two groups were significantly higher than the positive rates of single index detection (p < 0.05). Taking etiological examination as the gold standard, the sensitivity (92.59%) and specificity (90.17%) of the three combined detection methods were significantly higher than those of PCT, CRP, and FIB alone. Kappa test showed that the results of the combined detection and etiological examination were in good agreement (Kappa value = 0.847, p < 0.05). ROC curve analysis showed that the AUC of combined prediction of the three was 0.964, which was higher than that of single detection of 0.859, 0.832, and 0.871. Logistic regression analysis showed that serum PCT, CRP, and FIB were independent predictors of bacterial pneumonia, and the differences were statistically significant (p < 0.05). Pearson's correlation analysis showed that FIB level in the bacterial group was positively correlated with PCT and CRP. PCT was positively correlated with CRP., Conclusions: Compared with viral pneumonia, the levels of serum PCT, CRP, and FIB in patients with bacterial pneumonia are higher. Biochemical indexes can be used as independent predictors for the diagnosis of bacterial pneumonia, and have high diagnostic value. The combined detection of the three has the highest diagnostic efficiency, which is conducive to the clinical differential diagnosis of the early types of pneumonia infection.

Bacterial pneumonia is a considerable problem worldwide. Here, we follow the inter-kingdom respiratory tract microbiome (RTM) of a unique cohort of 38 hospitalized patients (n = 97 samples) with pneumonia caused by Legionella pneumophila. The RTM composition is characterized by diversity drops early in hospitalization and ecological species replacement. RTMs with the highest bacterial and fungal loads show low diversity and pathogen enrichment, suggesting high biomass as a biomarker for secondary and/or co-infections. The RTM structure is defined by a "commensal" cluster associated with a healthy RTM and a "pathogen" enriched one, suggesting that the cluster equilibrium drives the microbiome to recovery or dysbiosis. Legionella biomass correlates with disease severity and co-morbidities, while clinical interventions influence the RTM dynamics. Fungi, archaea, and protozoa seem to contribute to progress of pneumonia. Thus, the interplay of the RTM equilibrium, the pathogen load dynamics, and clinical interventions play a critical role in patient recovery., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

We describe the case of a 61-year-old diabetic man affected by Achromobacter denitrificans. He was immunocompetent and did not have any past history of chronic lung disease. The patient was treated with sensitive antibiotic meropenem 1 g, three times daily. To our knowledge, only one case of A. denitrificans pneumonia has been reported from the Indian subcontinent in an individual with underlying lung disease and none in a healthy person.

Introduction: The Japanese Respiratory Society (JRS) atypical pneumonia score is a useful tool for the rapid presumptive diagnosis of atypical pneumonia. We investigated the clinical features of community-acquired pneumonia (CAP) due to Chlamydia psittaci and validated the JRS atypical pneumonia score in patients with C. psittaci CAP., Methods: This study was conducted at 30 institutions and assessed a total of 72 sporadic cases with C. psittaci CAP, 412 cases with Mycoplasma pneumoniae CAP, and 576 cases with Streptococcus pneumoniae CAP., Results: Sixty-two of 72 patients with C. psittaci CAP had a history of avian exposure. Among the six parameters of the JRS score, matching rates of four parameters were significantly lower in the C. psittaci CAP than the M. pneumoniae CAP in the following parameters: age <60 years, no or minor comorbid illness, stubborn or paroxysmal cough, and absence of chest adventitious sounds. The sensitivity of the diagnosis of atypical pneumonia in patients with C. psittaci CAP was significantly lower than the M. pneumoniae CAP (65.3% and 87.4%, p < 0.0001). When the diagnostic sensitivity was analyzed for different ages, the diagnostic sensitivities for the C. psittaci CAP were 90.5% for non-elderly patients and 30.0% for elderly patients., Conclusions: The JRS atypical pneumonia score is a useful tool for distinguishing between C. psittaci CAP and bacterial CAP in patients aged <60 years, but not in patients aged ≥60 years. A history of avian exposure in middle-aged patients with normal white blood cell count may be suggestive of C. psittaci pneumonia., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2023 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Objective: The aim of this study was to explore the predictive value of the ratio of procalcitonin (PCT) in serum to Simpson's dominance index (SDI) in bronchoalveolar lavage fluid (BALF), in short-term prognosis of patients with severe bacterial pneumonia (SBP)., Methods: This is a retrospective review of case materials of 110 patients with SBP who selected BALF metagenomic next-generation sequencing technique in the intensive care unit (ICU) of the Affiliated Hospital of Yangzhou University from January 2019 and July 2022. Based on the acute physiology and chronic health status score II, within 24 h after admission to the ICU, patients were divided into a non-critical group ( n = 40) and a critical group ( n = 70). Taking death caused by bacterial pneumonia as the endpoint event, the 28-day prognosis was recorded, and the patients were divided into a survival group ( n = 76) and a death group ( n = 34). The SDI, PCT, C-reactive protein (CRP), PCT/SDI, and CRP/SDI were compared and analyzed., Results: Compared with the non-critical group, the critical group had a higher PCT level, a greater PCT/SDI ratio, a longer ventilator-assisted ventilation time (VAVT), and more deaths in 28 days. Compared with the survivors, the death group had a higher PCT level, a lower SDI level, and a greater PCT/SDI ratio. The SDI level was significantly negatively correlated with the VAVT ( r = -0.675, p < 0.05), while the PCT level, ratio of PCT/SDI, and ratio of CRP/SDI were remarkably positively correlated with VAVT ( r = 0.669, 0.749, and 0.718, respectively, p < 0.05). The receiver operating characteristic (ROC) curves analysis showed that the area under ROC curves of PCT/SDI predicting patient death within 28 days was 0.851, followed by PCT + SDI, PCT, SDI, and CRP/SDI (0.845, 0.811, 0.778, and 0.720, respectively). The sensitivity and specificity of PCT/SDI for predicting death were 94.1% and 65.8%, respectively, at the optimal value (11.56). Cox regression analysis displayed that PCT/SDI (HR = 1.562; 95% CI: 1.271 to 1.920; p = 0.039) and PCT (HR = 1.148; 95% CI: 1.105 to 1.314; p = 0.015) were independent predictors of death in patients., Conclusion: The ratio of PCT/SDI was a more valuable marker in predicting the 28-day prognosis in patients with SBP., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Sun, Liu, Zheng, Shan and Hou.)

Purpose: Procalcitonin (PCT) is an inflammatory marker elevated in bacteremia and bacterial pneumonia. We aimed to assess the real-world diagnostic accuracy of PCT in hospitalized patients with malignancy., Methods: A retrospective cohort of 715 patients with cancer who had PCT measured during 750 admissions was analyzed. Diagnosis of bacteremia was determined using blood culture data. Diagnosis of bacterial pneumonia was based on radiographic infiltrate and/or sputum culture. PCT's performance was assessed using receiver operating characteristic (ROC) curves, sensitivity, and specificity., Results: Patients had bacteremia, bacterial pneumonia, or both during 210 admissions (28%). PCT elevation above 0.5 ng/mL was significantly associated with diagnosed infection in the overall population (p < 0.0001) and in subgroups with solid tumor malignancies (p < 0.0001) and hematologic malignancies (p = 0.008). PCT was associated with infectious status in patients with any metastases, but not those with primary lung cancer, lung metastases, neuroendocrine tumors, febrile neutropenia, or history of bone marrow transplant (BMT). The area under the ROC curve for PCT in the overall population was 0.655. An ideal cutoff of 0.21 ng/mL led to a sensitivity of 60% and specificity of 59%. At cutoffs of 0.5 ng/mL and 0.05 ng/mL, PCT's sensitivity was 39% and 94%, while specificity was 79% and 17%, respectively., Conclusion: In this large cohort of hospitalized oncology patients, PCT elevation was associated with diagnosed bacteremia and/or bacterial pneumonia. However, specificity was limited, and PCT elevation was not associated with diagnosed infection in some subpopulations. While PCT may have some diagnostic utility for hospitalized oncology patients, values must be interpreted cautiously and considering clinical context., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Community-acquired pneumonia (CAP) is a major public health challenge worldwide. However, the aetiological and disease severity-related pathogens associated with CAP in adults in China are not well established based on the detection of both viral and bacterial agents., Methods: A multicentre, prospective study was conducted involving 10 hospitals located in nine geographical regions in China from 2014 to 2019. Sputum or bronchoalveolar lavage fluid (BALF) samples were collected from each recruited CAP patient. Multiplex real-time PCR and bacteria culture methods were used to detect respiratory pathogens. The association between detected pathogens and CAP severity was evaluated., Results: Among the 3,403 recruited eligible patients, 462 (13.58%) had severe CAP, and the in-hospital mortality rate was 1.94% (66/3,403). At least one pathogen was detected in 2,054 (60.36%) patients, with two or more pathogens were co-detected in 725 patients. The ten major pathogens detected were Mycoplasma pneumoniae (11.05%), Haemophilus influenzae (10.67%), Klebsiella pneumoniae (10.43%), influenza A virus (9.49%), human rhinovirus (9.02%), Streptococcus pneumoniae (7.43%), Staphylococcus aureus (4.50%), adenovirus (2.94%), respiratory syncytial viruses (2.35%), and Legionella pneumophila (1.03%), which accounted for 76.06-92.52% of all positive detection results across sampling sites. Klebsiella pneumoniae (p < 0.001) and influenza viruses (p = 0.005) were more frequently detected in older patients, whereas Mycoplasma pneumoniae was more frequently detected in younger patients (p < 0.001). Infections with Klebsiella pneumoniae, Staphylococcus aureus, influenza viruses and respiratory syncytial viruses were risk factors for severe CAP., Conclusions: The major respiratory pathogens causing CAP in adults in China were different from those in USA and European countries, which were consistent across different geographical regions over study years. Given the detection rate of pathogens and their association with severe CAP, we propose to include the ten major pathogens as priorities for clinical pathogen screening in China., (© 2023. The Author(s).)

Aim: This study compared exhaled carbon monoxide (CO) levels in patients hospitalized for bacterial and COVID-19-related viral community-acquired pneumonia. Materials & methods: The study included a total of 150 patients: 50 patients hospitalized for COVID-19 between February 2021 and March 2022, 50 patients with bacterial community-acquired pneumonia and 50 healthy controls. Results: In comparisons of exhaled CO levels among the groups, there was no significant difference between patients with bacterial pneumonia and controls, whereas patients with COVID-19 pneumonia had significantly higher exhaled CO levels compared with both the bacterial pneumonia and control groups (p < 0.001). Conclusion: Viral agents can directly affect the heme oxygenase system of the lower respiratory tract, leading to greater increases in ferritin and exhaled CO levels compared with bacterial pneumonia.

Aim: We aimed to assess whether detection of respiratory bacteria by multiplex polymerase chain reaction (PCR) testing associates with clinical outcomes in acutely ill children., Methods: This cross-sectional study enrolled children under the age of 18 with a suspected respiratory infection treated in a paediatric emergency department of Oulu University Hospital, Finland from January 2015 through December 2015. Nasopharyngeal samples were routinely analysed for 16 respiratory viruses and later, after storage, analysed with a multiplex PCR panel for seven respiratory bacteria., Results: At least one bacterial pathogen was detected in 600 out of the 1195 children (50%). The mean age was 3.3 (SD 3.7) years and 54% were boys. Atypical bacteria were associated with a risk of pneumonia (adjusted odds ratio [aOR] 14.1, 95% CI 3.98-50.1). Co-detection of rhinovirus with Streptococcus pneumoniae was not associated with risk of pneumonia (aOR 2.39, 95% CI 0.78-7.30). Detection of Streptococcus pneumoniae, Haemophilus influenzae or both was not associated with the risk of hospital admission or prescription of antibiotics., Conclusion: Nasopharyngeal detection of atypical bacteria in acutely ill children was associated with a markedly increased risk of pneumonia. The clinical utility of wide testing for other respiratory bacteria needs further evaluation., (© 2023 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)

Background: The 2019 Infectious Disease Society of America (IDSA) guidelines for the management of community-acquired bacterial pneumonia encourage the identification of locally validated risk factors for methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa to guide empiric therapy decisions for patients with community-acquired pneumonia (CAP). The guidelines urge clinicians to perform local validation to determine prevalence and risk factors pertinent to their institution. Objective: To determine the percentage of community-acquired pneumonia caused by multidrug-resistant organisms (MDROs) and assess risk factors potentially associated with multidrug-resistant organisms CAP at our hospital. Methods: This was a retrospective case control study analyzing patients admitted to the 344-bed community hospital with bacterial community-acquired pneumonia between January 1, 2019 and December 31, 2019. Univariate analysis and multivariate regression were performed to assess potential risk factors for MDRO pathogens. Results: MDROs were isolated in 41.3% of patients with culture-positive CAP (n=19/46), and 3.6% of patients with microbiological culture data within 48 hours of admission (19/527). Among patients with culture-positive CAP, hospitalization in the previous 90 days and receipt of antibiotics in the previous 90 days occurred more frequently in MDRO patients than non-MDRO patients (37% vs 11%, P =.032). No risk factors reached statistical significance in the multivariate regression. There were no differences in clinical outcomes between MDRO and non-MDRO patients. Conclusions: This study demonstrated a low overall prevalence of MDRO pathogens in patients with CAP. Potential risk factors for MDRO included hospitalization within the past 90 days and antibiotic use within the past 90 days.

Objective: This study is aimed at exploring the ability to use heparin-binding protein (HBP) in bronchoalveolar lavage fluid (BALF) to differentially diagnose bacterial infection from viral infection for severe community-acquired pneumonia (CAP) in critically ill children., Methods: A total of 181 children with severe CAP admitted to the intensive care unit (ICU) were included in this study. BALF and blood samples were collected within the first 24 hours of admission. BALF HBP and interleukin-6 (IL-6) concentrations and neutrophil percentage (N%) as well as blood HBP, IL-6, procalcitonin (PCT), C-reactive protein, white blood cell concentrations and N% were measured., Results: Of the enrolled children, 126 were confirmed to have bacterial pneumonia, and 55 were confirmed to have viral pneumonia. Blood HBP and PCT concentrations and N% and BALF HBP and IL-6 concentrations and N% were significantly higher in bacterial pneumonia than in viral pneumonia ( P < 0.05). In the bacterial pneumonia group, HBP and IL-6 concentrations and N% in BALF samples were all significantly higher than those in blood samples ( P < 0.001), and BALF HBP and IL-6 concentrations and N% were correlated with blood HBP and IL-6 concentrations and N%, respectively ( r = 0.439, 0.250, and 0.235, P < 0.01). BALF N% and blood N% were both correlated with BALF HBP concentrations and blood HBP concentrations, respectively ( r = 0.622 and 0.346, P < 0.001). ROC analysis revealed that BALF HBP showed the best ability to predict bacterial pneumonia, with an area under the curve of 0.994, a sensitivity of 95.24%, and a specificity of 100.00% at its optimal cutoff value of 74.05 ng/mL., Conclusion: BALF HBP might be a promising biomarker for the early discrimination of bacterial infection from viral infection in critically ill children with severe CAP., Competing Interests: The authors declare that there is no conflicts of interest regarding the publication of this article., (Copyright © 2023 Caizhi Huang et al.)

Objective: This scoping review will present a profile of methodological rigor and reporting quality of clinical practice guidelines for adults hospitalized with bacterial pneumonia., Introduction: An ideal clinical practice guideline is evidence-based and the product of a rigorous and robust literature-vetted process, yet reports show that rigor is not being achieved. Moreover, a new vulnerable population has been identified due to COVID-19, increasing the need for high quality clinical practice guidelines. Preliminary searches yielded no scoping or systematic reviews on methodological rigor and reporting quality of clinical practice guidelines used for managing bacterial pneumonia in hospitalized adults., Inclusion Criteria: This review will consider current national and international clinical practice guidelines for management of hospitalized adult patients with either suspected or confirmed primary bacterial pneumonia. The review will include adult patients with multiple diagnoses if there is a clearly delineated clinical practice guideline for pneumonia., Methods: A 3-step search strategy will be conducted using JBI methodology for scoping reviews. After an initial MEDLINE search for keywords, a broad search of 7 databases, 1 simultaneous platform, gray literature, specialty organizations, and international guideline groups will be conducted from 2017 to the present, in any language. Reference lists will be screened for additional sources. A 2-step screening process will be used to identify eligible clinical practice guidelines. Three reviewers will independently extract data using a standardized form. Domain scores will be analyzed and presented as percentages, and the results will be interpreted as map trends., Details of This Review Project Are Available at: Open Science Framework https://osf.io/eucqy/., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 JBI.)

This research aimed to explore the clinical value of C-reactive protein (CRP), procalcitonin (PCT), and serum amyloid A (SAA) in early diagnosis of bacterial pneumonia. CRP, PCT, and SAA levels of children with bacterial pneumonia, children with non-bacterial pneumonia, and healthy children were compared. The sensitivity and specificity of CRP, PCT, and SAA in the diagnosis of bacterial pneumonia in children were compared. CRP, PCT, and SAA levels were significantly lower in healthy children when compared with children with Community acquired pneumonia (CAP). ROC analyses showed that CRP, PCT, and SAA all had good accuracy in distinguishing bacterial pneumonia from non-bacterial pneumonia. The combination of CRP, PCT, and SAA further enhanced the accuracy in distinguishing bacterial pneumonia from non-bacterial pneumonia. In conclusion, the expression levels of CRP, PCT, and SAA could indicate the status of bacterial pneumonia. The combined test of CRP, PCT, and SAA had the highest diagnostic accuracy., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: To develop a rapid and low-cost method for 16S rDNA nanopore sequencing., Methods: This was a prospective study on a 16S rDNA nanopore sequencing method. We developed this nanopore barcoding 16S sequencing method by adding barcodes to the 16S primer to reduce the reagent cost and simplify the experimental procedure. Twenty-one common pulmonary bacteria (7 reference strains, 14 clinical isolates) and 94 samples of bronchoalveolar lavage fluid from children with severe pneumonia were tested. Results indicating low-abundance pathogenic bacteria were verified with the polymerase chain reaction (PCR). Further, the results were compared with those of culture or PCR., Results: The turnaround time was shortened to 6~8 hours and the reagent cost of DNA preparation was reduced by employing a single reaction adding barcodes to the 16S primer in advance. The accuracy rate for the 21 common pulmonary pathogens with an abundance ≥ 99% was 100%. Applying the culture or PCR results as the gold standard, 71 (75.5%) of the 94 patients were positive, including 25 positive cultures (26.6%) and 52 positive quantitative PCRs (55.3%). The median abundance in the positive culture and qPCR samples were 29.9% and 6.7%, respectively. With an abundance threshold increase of 1%, 5%, 10%, 15% and 20%, the test sensitivity decreased gradually to 98.6%, 84.9%, 72.6%, 67.1% and 64.4%, respectively, and the test specificity increased gradually to 33.3%, 71.4%, 81.0%, 90.5% and 100.0%, respectively., Conclusions: The nanopore barcoding 16S sequencing method can rapidly identify the pathogens causing bacterial pneumonia in children., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Chen, Mao, Lai, Xu, Zhang, Wu, Yang, Zhao, Liu, Xiao, Tang, Meng, Wang, Shi, Chen and Shu.)

Background: Early detection of Rhodococcus equi pneumonia in foals is essential for horse health and for veterinarians., Objectives: This study aimed to demonstrate the usefulness of assessing the serum concentration of acute-phase proteins (APPs) in the early diagnosis of pneumonia., Methods: The study evaluated APPs in 19 Arabian foals with R. equi pneumonia and compared them with 18 normal Arabian foals in equestrian clubs in Tabriz, Iran. Affected foals were identified through history, clinical findings and bacterial culture of tracheal washing. Biochemical methods and polymerase chain reaction tests were performed by examining the 16S rRNA and vapA genes to confirm the diagnosis of bacterial isolates. Blood samples were taken from all sick and healthy horses, and their serum was isolated. APPs in the serum were measured in all the samples., Results: Rhodococcosis increased the serum concentration of haptoglobin (Hp) and serum amyloid A (SAA) (p < 0.001). The relationship between SAA and Hp was meaningful in the infected group (r = 0.933) but not in the healthy group. In cases where there are clinical findings of R. equi pneumonia, the concentration of SAA and Hp can help the effectiveness of treatment., - Conclusions: Serum concentration analysis of APPs can be helpful in early diagnosis and successfully treating foals with R. equi pneumonia., (© 2022 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

All modern advances notwithstanding, pneumonia remains a common infection with substantial morbidity and mortality. Understanding of the etiology of pneumonia continues to evolve as new techniques enable identification of already known organisms and as new organisms emerge. We now review the etiology of pneumonia (at present often called "community-acquired pneumonia") beginning with classic bacteriologic techniques, which identified Streptococcus pneumoniae as the overwhelmingly common cause, to more modern bacteriologic studies, which emphasize Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, Enterobacteriaceae , Pseudomonas, and normal respiratory flora. Urine antigen detection is useful in identifying Legionella and pneumococcus. The low yield of bacteria in recent studies is due to the failure to obtain valid sputum samples before antibiotics are administered. The use of high-quality sputum specimens enables identification of recognized ("typical") bacterial pathogens as well as a role for commensal bacteria ("normal respiratory flora"). Nucleic acid amplification technology for viruses has revolutionized diagnosis, showing the importance of viral pneumonia leading to hospitalization with or without coinfecting bacterial organisms. Quantitative PCR study of sputum is in its early stages of application, but regular detection of high counts of bacterial DNA from organisms that are not seen on Gram stain or grown in quantitative culture presents a therapeutic dilemma. This finding may reflect the host microbiome of the respiratory tract, in which case treatment may not need to be given for them. Finally, host transcriptional signatures might enable clinicians to distinguish between viral and bacterial pneumonia, an important practical consideration.

Pneumonia is frequently encountered in clinical practice, and Gram-negative bacilli constitute a significant proportion of its aetiology, especially when it is acquired in a hospital setting. With the alarming global rise in multidrug resistance in Gram-negative bacilli, antibiotic therapy for treating patients with pneumonia is challenging and must be guided by in vitro susceptibility results. In this review, we provide an overview of antibiotics newly approved for the treatment of pneumonia caused by Gram-negative bacilli. Ceftazidime-avibactam, imipenem-relebactam and meropenem-vaborbactam have potent activity against some of the carbapenem-resistant Enterobacterales, especially Klebsiella pneumoniae carbapenemase producers. Several novel antibiotics have potent activity against multidrug-resistant Pseudomonas aeruginosa , such as ceftazidime-avibactam, ceftolozane-tazobactam, imipenem-relabactam and cefiderocol. Cefiderocol may also play an important role in the management of pneumonia caused by Acinetobacter baumannii , along with plazomicin and eravacycline., Competing Interests: Conflict of interest: Outside the submitted work, M. Bassetti reports research grants and/or advisor/consultant and/or speaker/chairman fees from Bayer, BioMerieux, Cidara, Cipla, Gilead, Menarini, MSD, Pfizer and Shionogi. Outside the submitted work, D.R. Giacobbe reports investigator-initiated grants from Pfizer, Shionogi and Gilead Italia, and speaker and/or advisory board fees from Pfizer and Tillotts Pharma. The other authors have no conflicts of interest to declare., (Copyright ©The authors 2022.)

Severe Community Acquired Pneumonia (SCAP) challenges public health globally. Considerable improvements in molecular pathogen testing emerged in the last few years. Our prospective study combinedly used traditional culture, antigen tests, PCR and mNGS in SCAP pathogen identification with clinical outcomes. From June 2018 to December 2019, we conducted a multi-centre prospective study in 17 hospitals of SCAP patients within 48 hours of emergency room stay or hospitalization in China. All clinical data were uploaded into an online database. Blood, urine and respiratory specimens were collected for routine culture, antigen detection, PCR and mNGS as designed appropriately. Aetiology confirmation was made by the local attending physician group and scientific committee according to microbiological results, clinical features, and response to the treatment. Two hundred seventy-five patients were included for final analysis. Combined detection methods made identification rate up to 74.2% (222/299), while 14.4% (43/299) when only using routine cultures and 40.8% (122/299) when not using mNGS. Influenza virus (23.2%, 46/198), S. pneumoniae (19.6%, 39/198), Enterobacteriaceae (14.6%, 29/198), Legionella pneumophila (12.6%, 25/198), Mycoplasma pneumoniae (11.1%, 22/198) were the top five common pathogens. The in-hospital mortality of patients with pathogen identified and unidentified was 21.7% (43/198) and 25.9% (20/77), respectively. In conclusion, early combined detection increased the pathogen identification rate and possibly benefitted survival. Influenza virus, S. pneumoniae , Enterobacteriaceae was the leading cause of SCAP in China, and there was a clear seasonal distribution pattern of influenza viruses. Physicians should be aware of the emergence of uncommon pathogens, including Chlamydia Psittaci and Leptospira .

Bacterial pneumonia in pregnancy is the most common fatal non-obstetrical infection and is associated with poorer maternal and fetal outcomes. Risk factors include normal physiological and anatomic changes that occur during pregnancy. In this review, we will discuss the etiological pathogens of bacterial pneumonias in pregnancy and its common complications, including both maternal and fetal outcomes. We will also review the diagnosis and management of bacterial pneumonia in the outpatient and inpatient setting and highlight the major pregnancy and lactation considerations when choosing antibiotic therapies., Competing Interests: Declaration of competing interest The authors have no conflict of interests to disclose., (Copyright © 2022. Published by Elsevier Ltd.)

Introduction and Objective: Endocan has been used as a biomarker in the differential diagnosis of pulmonary diseases in adults. However, there are only a limited number of studies on its use in children. In this context, the objective of this study is to evaluate the relationship between serum endocan levels in children with bacterial and viral pneumonia. Materials and Methods: The population of this prospective case-control study consisted of hospitalized children aged 1 month to 15 years diagnosed with pneumonia between August 2020 and July 2021, whereas the control group consisted of randomly selected healthy children. The demographic and clinical characteristics of all participants were recorded. Participants' endocan levels, white blood cell (WBC) and neutrophil counts, and C-reactive protein (CRP) and procalcitonin (PCT) levels were measured within the scope of the laboratory tests. Results: The study sample consisted of 41 children, of whom 21 had bacterial pneumonia and 20 had viral pneumonia, whereas the control group consisted of 47 healthy children. Serum endocan levels, WBC and neutrophil counts, and PCT and CRP levels were significantly higher in children with bacterial pneumonia than in children with viral pneumonia and healthy children ( P  < 0.05). Additionally, serum endocan levels were significantly higher in children with viral pneumonia than in healthy children ( P  < 0.001). The endocan levels in children with bacterial pneumonia were significantly associated with the need for intensive care ( P  = 0.004) and correlated with the length of hospital stay (LoS) ( r  = 0.592, P  = 0.005). Conclusion: The findings of this study indicated that serum endocan levels can be used in the differential diagnosis of bacterial and viral pneumonias. Additionally, it was found that the need for intensive care and LoS were significantly correlated with endocan levels in children with bacterial pneumonia.

Background: Historically, procalcitonin(PCT) has been used as a predictor of bacterial infection and to guide antibiotic therapy in hospitalized patients. The purpose of this study was to determine PCT's diagnostic utility in predicting secondary bacterial pneumonia in critically ill patients with severe COVID-19 pneumonia. Methods: A retrospective cohort study was conducted in COVID-19 adults admitted to the ICU between March 2020, and March 2021. All included patients had a PCT level within 72 h of presentation and serum creatinine of <1.5mg/dL. A PCT threshold of 0.5ng/mL was used to compare patients with high( ≥ 0.5ng/mL) versus low(< 0.5ng/mL) PCT. Bacterial pneumonia was defined by positive respiratory culture. A receiver operating characteristics (ROC) curve was utilized to evaluate PCT as a diagnostic test for bacterial pneumonia, with an area under the curve(AUC) threshold of 0.7 to signify an accurate diagnostic test. A multivariable model was constructed to identify variables associated with in-hospital mortality. Results: There were 165 patients included: 127 low PCT versus 38 high PCT. There was no significant difference in baseline characteristics, vital signs, severity of disease, or outcomes among low versus high PCT groups (all p  > 0.05). While there was no difference in bacterial pneumonia in low versus high groups (34(26.8%) versus 12(31.6%), p   =  0.562), more patients in the high PCT group had bacteremia (19(15%) versus 11(28.9%), p   =  0.050). Sensitivity was 26.1% and specificity was 78.2% for PCT to predict bacterial pneumonia coinfection in ICU patients with COVID-19 pneumonia. ROC yielded an AUC 0.54 ( p  = 0.415). After adjusting for LDH>350U/L and creatinine in multivariable regression, PCT did not enhance performance of the regression model. Conclusions: PCT offers little to no predictive utility in diagnosing concomitant bacterial pneumonia in critically ill patients with COVID-19 nor in predicting increased severity of disease or worse outcomes including mortality.

Background: Current diagnostics do not permit reliable differentiation of bacterial from viral causes of lower respiratory tract infection (LRTI), which may lead to over-treatment with antibiotics for possible bacterial community-acquired pneumonia (CAP)., Objectives: We sought to describe variation in the diagnosis and treatment of bacterial CAP among children hospitalized with LRTIs and determine the association between CAP diagnosis and outcomes., Design, Setting and Participants: This multicenter cross-sectional study included children hospitalized between 2017 and 2019 with LRTIs at 42 children's hospitals., Main Outcome and Methods: We calculated the proportion of children with LRTIs who were diagnosed with and treated for bacterial CAP. After adjusting for confounders, hospitals were grouped into high, moderate, and low CAP diagnosis groups. Multivariable regression was used to examine the association between high and low CAP diagnosis groups and outcomes., Results: We identified 66,581 patients hospitalized with LRTIs and observed substantial variation across hospitals in the proportion diagnosed with and treated for bacterial CAP (median 27%, range 12%-42%). Compared with low CAP diagnosing hospitals, high diagnosing hospitals had higher rates of CAP-related revisits (0.6% [95% confidence interval: 0.5, 0.7] vs. 0.4% [0.4, 0.5], p = .04), chest radiographs (58% [53, 62] vs. 46% [41, 51], p = .02), and blood tests (43% [33, 53] vs. 26% [19, 35], p = .046). There were no significant differences in length of stay, all-cause revisits or readmissions, CAP-related readmissions, or costs., Conclusion: There was wide variation across hospitals in the proportion of children with LRTIs who were treated for bacterial CAP. The lack of meaningful differences in clinical outcomes among hospitals suggests that some institutions may over-diagnose and overtreat bacterial CAP., (© 2022 Society of Hospital Medicine.)

Background: Community-acquired pneumonia (CAP) causes substantial morbidity and mortality in adults worldwide. The etiology of CAP often remains uncertain, and therapy is empirical. Thus, there is still room for improvement in the diagnosis of pneumonia., Methods: Adults aged >20 years who presented at the outpatient or emergency departments of Linkou and Keelung Chang Gung Memorial Hospital with CAP were prospectively included between November 2016 and December 2018. We collected respiratory specimens for culture and molecular testing and calculated the incidence rates of CAP according to pathogens., Results: Of 212 hospitalized adult patients with CAP, 69.3% were male, and the median age of the patients was 67.8 years. Bacterial pathogens were detected in 106 (50%) patients, viruses in 77 (36.3%), and fungal pathogens in 1 patient (0.5%). The overall detection rate (culture and molecular testing method) was 70.7% (n = 150). Traditional microbial culture yielded positive results in 36.7% (n = 78), molecular testing in 61.3% (n = 130). The most common pathogens were influenza (16.1%), followed by Klebsiella pneumoniae (14.1%), Pseudomonas aeruginosa (13.6%), human rhinovirus (11.8%), and Streptococcus pneumoniae (9.9%). Multiple pathogen co-infections accounted for 28.7% (n = 61), of which co-infection with K. pneumoniae and human rhinovirus comprised the largest proportion., Conclusions: Molecular diagnostic testing could detect 23.6% more pathogens than traditional culture techniques. However, despite the current diagnostic tests, there is still the possibility that no pathogen was detected., (Copyright © 2021. Published by Elsevier B.V.)

Introduction: The use of mechanical ventilators in the intensive care unit (ICU) is often associated with higher risk of respiratory tract infections, including ventilator-associated pneumonia (VAP). Concomitant bacterial-viral infection was reported to worsen patient's clinical condition. This study evaluated the rate of concomitant bacterial-viral infections in patients with VAP and analyzed their clinical outcomes., Methodology: In this retrospective observational study 107 patients diagnosed with VAP and admitted in ICU with mechanical ventilator support between April 2018 and May 2019 in the Department of Respiratory Medicine, Dachang Hospital, Shanghai, China were included. 27 most commonly involved lower respiratory tract infection (LRTI) pathogens (bacteria and virus) and seven genetic markers of antibiotic resistance were detected and analyzed using Biofire® FilmArray® Pneumonia Panel plus (bioMérieux SA, Paris, France)., Results: Of the 107 patients, 45 (42.1%) patients had bacterial infection alone (bacterial group), 26 (24.3%) had virus infection alone (viral group) and 24 (22.4%) patients had concomitant bacterial-viral infection (mixed group). Sixty-nine (64.5%) and 50 (46.7%) patient samples were positive for bacterial (bacterial and mixed groups) and viral (viral and mixed groups) detection, respectively. Streptococcus pneumonia (11.2%) and Influenza A (17, 15.9%), were the predominantly identified bacterial and viral species. The blaCTX-M (21.5%) was the predominant resistance gene detected. Twenty-four (22.4%) patients were positive for concomitant bacterial-viral infection; Staphylococcus aureus and Influenza A were the most common bacterial-viral combination identified., Conclusions: Concomitant bacterial-viral infection was higher compared to previously published studies and the increased duration of mechanical ventilation was associated with increased disease severity., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2022 Xiaoyun Shen, Bo Feng, Weiyi Shi, Wenming Cheng, Tiefeng Zhang.)

Early introduction of appropriate antibiotherapy is one of the major prognostic-modifying factors in community acquired pneumonia (CAP). Despite established guidelines for empirical therapy, several factors may influence etiology and, consequently, antibiotic choices. The aims of this study were to analyze the etiology of CAP in adults admitted to a northern Portugal University Hospital and evaluate the yield of the different methods used to reach an etiological diagnosis, as well as analyze of the impact of patient demographic and clinical features on CAP etiology. We retrospectively analyzed 1901 cases of CAP with hospitalization. The diagnostic performance increased significantly when blood and sputum cultures were combined with urinary antigen tests. The most frequent etiological agent was Streptococcus pneumoniae (45.7%), except in August, when it was overtaken by gram-negative bacilli (GNB) and Legionella pneumophila infections. Viral infections were almost exclusive to winter and spring. A negative microbiological result was associated with increasing age, non-smoking and lack of both blood/sputum cultures. Younger age was a predictor for S. pneumoniae, Influenza and L. pneumophila infections. Active smoking without any previously known respiratory disease was a risk factor for legionellosis. COPD was associated with Haemophilus influenzae cases, while dementia was typical in GNB and S. aureus patients. Diabetes mellitus (DM) and heart disease were negative predictors of S. pneumoniae and H. influenzae, respectively. P. aeruginosa was an independent risk factor for mortality (OR 13.02, 95% CI 2.94-57.7). This study highlights the importance of a comprehensive microbiological diagnostic workup and provides clues to predicting the most probable CAP causative agents, based on a patient's clinical profile. These may be taken into account when establishing first line antibiotherapy., (Copyright © 2020 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)

Ferritin, the central iron storage protein, has attracted attention as a biomarker of severe COVID-19. Few studies have investigated regulators of iron metabolism in the context of COVID-19. The aim was to evaluate biomarkers for iron metabolism in the acute phase response to community-acquired pneumonia (CAP) caused by SARS-CoV-2 compared with CAP caused by bacteria or influenza virus in hospitalized patients. A cross-sectional study of 164 patients from the Surviving Pneumonia Cohort recruited between January 8, 2019 and May 26, 2020. Blood samples were collected at admission and analyzed for levels of C-reactive protein (CRP), ferritin, soluble transferrin receptor, erythroferrone, and hepcidin. Median (IQR) hepcidin was higher in SARS-CoV-2 with 143.8 (100.7-180.7) ng/mL compared with bacterial and influenza infection with 78.8 (40.1-125.4) and 53.5 (25.2-125.8) ng/mL, respectively. The median ferritin level was more than 2-fold higher in patients with SARS-CoV-2 compared with the other etiologies (p < 0.001). Patients with SARS-CoV-2 had lower levels of erythroferrone and CRP compared with those infected with bacteria. Higher levels of hepcidin and lower levels of erythroferrone despite lower CRP levels among patients with SARS-CoV-2 compared with those infected with bacteria indicate alterations in iron metabolism in patients with SARS-CoV-2 infection., (© 2022 APMIS. Published by John Wiley & Sons Ltd.)

MicroRNAs (miRNAs), which were initially discovered in Caenorhabditis elegans, can regulate gene expression by recognizing cognate sequences and interfering with the transcriptional or translational machinery. The application of bioinformatics tools for structural analysis and target prediction has largely driven the investigation of certain miRNAs. Notably, it has been found that certain miRNAs which are widely involved in the inflammatory response and immune regulation are closely associated with the occurrence, development, and outcome of bacterial pneumonia. It has been shown that certain miRNA techniques can be used to identify related targets and explore associated signal transduction pathways. This enhances the understanding of bacterial pneumonia, notably for "refractory" or drug-resistant bacterial pneumonia. Although these miRNA-based methods may provide a basis for the clinical diagnosis and treatment of this disease, they still face various challenges, such as low sensitivity, poor specificity, low silencing efficiency, off-target effects, and toxic reactions. The opportunities and challenges of these methods have been completely reviewed, notably in bacterial pneumonia. With the continuous improvement of the current technology, the miRNA-based methods may surmount the aforementioned limitations, providing promising support for the clinical diagnosis and treatment of "refractory" or drug-resistant bacterial pneumonia., (© 2022. The Author(s).)

The COVID-19 pandemic has drawn considerable attention to viral pneumonia from clinicians, public health authorities, and the general public. With dozens of viruses able to cause pneumonia in humans, differentiating viral from bacterial pneumonia can be very challenging in clinical practice using traditional diagnostic methods. Precision medicine is a medical model in which decisions, practices, interventions, and therapies are adapted to the individual patient on the basis of their predicted response or risk of disease. Precision medicine approaches hold promise as a way to improve outcomes for patients with viral pneumonia. This review describes the latest advances in the use of precision medicine for diagnosing and treating viral pneumonia in adults and discusses areas where further research is warranted., (© 2022. The Author(s).)

Few studies have described the key features and prognostic roles of lung microbiota in patients with severe community-acquired pneumonia (SCAP). We prospectively enrolled consecutive SCAP patients admitted to ICU. Bronchoscopy was performed at bedside within 48 h of ICU admission, and 16S rRNA gene sequencing was applied to the collected bronchoalveolar lavage fluid. The primary outcome was clinical improvements defined as a decrease of 2 categories and above on a 7-category ordinal scale within 14 days following bronchoscopy. Sixty-seven patients were included. Multivariable permutational multivariate analysis of variance found that positive bacteria lab test results had the strongest independent association with lung microbiota (R 2 = 0.033; P = 0.018), followed by acute kidney injury (AKI; R 2 = 0.032; P = 0.011) and plasma MIP-1β level (R 2 = 0.027; P = 0.044). Random forest identified that the families Prevotellaceae, Moraxellaceae, and Staphylococcaceae were the biomarkers related to the positive bacteria lab test results. Multivariable Cox regression showed that the increase in α-diversity and the abundance of the families Prevotellaceae and Actinomycetaceae were associated with clinical improvements. The positive bacteria lab test results, AKI, and plasma MIP-1β level were associated with patients' lung microbiota composition on ICU admission. The families Prevotellaceae and Actinomycetaceae on admission predicted clinical improvements., (© 2021. Higher Education Press.)

Background: Inflammatory biomarkers are associated with severity of coronavirus disease 2019 (COVID-19). However, direct comparisons of their utility in COVID-19 versus other respiratory infections are largely missing., Objective: We aimed to investigate the prognostic utility of various inflammatory biomarkers in COVID-19 compared to patients with other respiratory infections., Materials and Methods: Patients presenting to the emergency department with symptoms suggestive of COVID-19 were prospectively enrolled. Levels of Interleukin-6 (IL-6), c-reactive protein (CRP), procalcitonin, ferritin, and leukocytes were compared between COVID-19, other viral respiratory infections, and bacterial pneumonia. Primary outcome was the need for hospitalisation, secondary outcome was the composite of intensive care unit (ICU) admission or death at 30 days., Results: Among 514 patients with confirmed respiratory infections, 191 (37%) were diagnosed with COVID-19, 227 (44%) with another viral respiratory infection (viral controls), and 96 (19%) with bacterial pneumonia (bacterial controls). All inflammatory biomarkers differed significantly between diagnoses and were numerically higher in hospitalized patients, regardless of diagnoses. Discriminative accuracy for hospitalisation was highest for IL-6 and CRP in all three diagnoses (in COVID-19, area under the curve (AUC) for IL-6 0.899 [95%CI 0.850-0.948]; AUC for CRP 0.922 [95%CI 0.879-0.964]). Similarly, IL-6 and CRP ranged among the strongest predictors for ICU admission or death at 30 days in COVID-19 (AUC for IL-6 0.794 [95%CI 0.694-0.894]; AUC for CRP 0.807 [95%CI 0.721-0.893]) and both controls. Predictive values of inflammatory biomarkers were generally higher in COVID-19 than in controls., Conclusion: In patients with COVID-19 and other respiratory infections, inflammatory biomarkers harbour strong prognostic information, particularly IL-6 and CRP. Their routine use may support early management decisions., Competing Interests: RT has received speaker honoraria/consulting honoraria from Abbott, Amgen, Astra Zeneca, Roche, Siemens, Singulex, and Thermo Scientific BRAHMS, outside the submitted work. GK has received consultant fees from Janssen, outside the submitted work. Authors not named here have disclosed no competing interests. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Atypical agents such as Mycoplasma, Legionella, Chlamydia species, and Coxiella burnetii (Q-fever agent) are responsible for some adult community-acquired pneumonia (CAP). Insufficient studies on this topic can be blamed for the failure to include atypical pathogens in empirical management. We followed adult CAP cases for two years, and samples (respiratory and serum) were tested by culture, ELISA (IgM, IgG, and IgA), and PCR. A risk factor analysis was performed. Overall in 21.3% adult CAP patients, atypical agents found were Mycoplasma pneumoniae (51.5%), Legionella pneumophila (28.8%), and Chlamydophila pneumoniae (19.7%). However, amongst patients <60 years of age and in the summer season, the proportion of atypical agents increased significantly. There is thus a need to re-examine empirical antibiotic regimes.