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Purpose: Patients with bacterial, fungal, and viral community-acquired pneumonia (CAP) were studied to determine their metabolic profiles., Methods: Loop-mediated isothermal amplification technology and nucleic acid sequence-dependent amplification combined with microfluidic chip technology were applied to screen multiple pathogens from respiratory tract samples. Eighteen patients with single bacterial infection (B-CAP), fifteen with single virus infection (V-CAP), twenty with single fungal infection (F-CAP), and twenty controls were enrolled. UHPLC-MS/MS analysis of untargeted serum samples for metabolic profiles. Multiple linear regression and Spearman's rank correlation analysis were used to determine associations between metabolites and clinical parameters. The sensitivity and specificity of the screened metabolites were also examined, along with their area under the curve., Results: The metabolic signatures of patients with CAP infected by bacteria, viruses, and fungi were markedly different from those of controls. The abundances of 45, 56, and 79 metabolites were significantly unbalanced. Among these differential metabolites, 11, 13, and 29 were unique to the B-CAP, V-CAP, and F-CAP groups, respectively. Bacterial infections were the only known causes of disturbances in the pentose and glucuronate and aldarate and ascorbate metabolism interconversions metabolic pathway., Conclusions: Serum metabolomic techniques based on UHPLC-MS/MS may identify differences between individuals with CAP who have been infected by various pathogens, and they can also build a metabolite signature for early detection of the origin of infection and prompt care.

Background: The typical clinical symptoms of psittacosis pneumonia include fever, dry cough, and chills. Sudden sensorineural hearing loss is a relatively uncommon condition in pneumonia caused by Chlamydia psittaci. In this study, we reported a rare case of Chlamydia psittaci pneumonia presented as hearing loss., Case Presentation: A 65-year-old man presented to our hospital with sudden hearing loss, cough with sputum, and fever for the last three days. Chest computed tomography revealed inflammation of the left lung and poor response to broad-spectrum antibiotics. The metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid identified the sequence of Chlamydia psittaci. Subsequently, antibiotic treatment was adjusted to doxycycline hydrochloride and moxifloxacin, resulting in significant improvement in both hearing loss and lung infection., Conclusions: Sudden sensorineural hearing loss as an extrapulmonary feature of Chlamydia psittaci pneumonia is extremely rare. Although the exact mechanism remains unclear, this case report described a patient with sudden bilateral sensorineural hearing loss as a presenting feature of Chlamydia psittaci pneumonia, illustrating the importance of the extrapulmonary features of atypical pneumonia. The mNGS test could provide early diagnosis. Many patients had a good prognosis with prompt and effective treatment., Competing Interests: Declarations Ethics approval and consent to participate The study protocol was approved by the Ethics Committee of Dongyang Hospital affiliated to Wenzhou Medical University (Number 2024-YX-065). An informed consent was signed by the patient. Consent for publication Written informed consent was obtained from the patient for publication of this case report. Disclosure The authors have nothing to disclose. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

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: Streptococcus salivarius is an opportunistic pathogen, and there have been no reported cases of Streptococcus salivarius pneumonia to date. Pneumomediastinum is usually secondary to tracheal or esophageal injury and is very rare as a complication of pneumonia. We report a case of Streptococcus salivarius pneumonia complicated by pneumomediastinum, aiming to enhance clinicians' awareness of rare pathogens and uncommon complications in pneumonia., Case Presentation: The patient, a 36-year-old male, presented with a persistent cough and sputum production for one week, accompanied by a sore throat that had developed just one day prior. Chest computed tomography (CT) disclosed pneumomediastinum alongside obstructive atelectasis in the left lower lobe. Streptococcus salivarius infection was conclusively identified through bronchoalveolar lavage metagenomic next-generation sequencing (mNGS), as well as smear and culture analyses. The patient was administered intravenous amoxicillin-clavulanate potassium for a duration of seven days as part of the anti-infection regimen. Given the stability of the patient's respiratory and circulatory systems, a tube drainage procedure was deemed unnecessary. Post-treatment, the patient's clinical symptoms notably improved. A subsequent chest CT scan revealed the re-expansion of the left lower lung and near-complete resolution of pneumomediastinum., Conclusion: There are numerous pathogens that can cause pneumonia. While focusing on common pathogens, it is important not to overlook rare ones. When considering infections from rare pathogens, it is recommended to promptly perform a bronchoscopy and submit bronchoalveolar lavage fluid for mNGS to improve pathogen detection rates. During the diagnosis and treatment of pneumonia, it is crucial to be vigilant for rare complications. When a patient presents with symptoms such as dyspnea or subcutaneous emphysema, it is advisable to immediately perform a chest CT scan to rule out pneumomediastinum., (© 2024. The Author(s).)

Background: For patients with pneumonia, the rapid detection of pathogens is still a major global problem in clinical practice because traditional diagnostic techniques for infection are time-consuming and insensitive. Metagenomic next-generation sequencing (mNGS) is a novel technique that has the potential to improve pathogen diagnosis. This study aimed to investigate the microbiological diagnostic ability of mNGS compared with conventional culture and to determine the optimal time to test patients for pneumonia., Methods: A prospective study using data from June 2020 to June 2021 was performed at a tertiary teaching hospital in China. We included 56 patients from all adult patients with a clinical diagnosis of pneumonia. Blood and bronchoalveolar lavage fluid (BALF) samples were taken for simultaneous mNGS and conventional culture testing., Results: All 56 patients underwent both conventional culture and mNGS. Of these patients, 37 were diagnosed with severe pneumonia and 17 were diagnosed with non-severe pneumonia. The top three pathogenic bacteria detected by mNGS were Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Enterococcus faecium was detected more frequently in the non-severe pneumonia group (4 vs. 0, p < 0.05). The findings revealed that the detection rate of mNGS (84%) was superior to that of conventional culture methods (48%). Notably, the percentage of mNGS-positive BALF samples (46/56, 82.14%) was significantly greater than that of blood samples (27/56, 48.21%). The etiological comparison demonstrated that mNGS-positive samples, which received clinical approval, tended to be associated with a more normalized temperature, lower PCO2 levels, and a higher SOFA score than mNGS-negative samples (p = 0.022, p = 0.0.028, and p = 0.038, respectively)., Conclusions: In this study, we discovered that the etiology of lung infections frequently involves multiple pathogens. The use of mNGS in BALF is instrumental for detecting nonviral pathogens associated with lung infections. Although the rate of positive blood NGS results is significantly influenced by various clinical factors, for patients suspected of having viral, Legionella, or tsutsugamushi infections, plasma mNGS could serve as a complementary diagnostic tool., (© 2024. The Author(s).)

Background: The MeMed BV Test produces a score that increases with increasing likelihood of bacterial infection. We evaluated its association with radiographic pneumonia in children., Methods: We performed a secondary analysis of a multicenter prospective study of febrile children 90 days to 18 years presenting to an emergency department. We evaluated the association of the MeMed BV test with radiographic pneumonia in adjusted logistic regression models., Results: Of 182 children, 74 (41%) had radiographic pneumonia. Among children with a high likelihood of having viral illness per the BV test, 26% had radiographic pneumonia; this increased to 64% among those with a BV test which indicated a high likelihood of bacterial infection. The sensitivity and specificity for radiographic pneumonia when using a BV test classification of moderate or high likelihood of bacterial infection were 60.8% and 62.0%, respectively. A BV test indicating the highest likelihood of bacterial infection had 23.61 higher adjusted odds (95% confidence interval 6.30-88.6) of radiographic pneumonia. The most common radiographic finding among children classified as having a high likelihood of viral infection by the BV test was interstitial opacities. The most common finding among children classified as having a high likelihood of bacterial infection were infiltrates. Except for antibiotic use, clinical outcomes occurred in similar proportions by BV category., Conclusions: Children with moderate to high likelihoods of bacterial infection on the BV test had higher odds of radiographic pneumonia. Apart from antibiotic use, the test was not significantly associated with clinical outcomes in this study., (Copyright © 2024 by the American Academy of Pediatrics.)

Diagnosing the cause of death can be challenging, particularly for patients with no prior history of visits to the treating hospital. We encountered a case involving a 76-year-old male who was discovered in a state of cardiopulmonary arrest at his home and subsequently declared deceased in our hospital due to severe pneumonia. He had exhibited symptoms of fever over 37°C and severe coughing for several days. Despite consulting a primary care physician one day prior, his symptoms worsened. Autopsy findings revealed an increase in lung weight and diffuse changes in parenchyma. Histological analysis showed numerous inflammatory cells and exudate within the alveoli. Gram and Periodic acid-Schiff staining were negative, but slight staining was observed in the cytoplasm of macrophages by Warthin-starry and Gimenez stains. Tests using a pan bacterial/viral detection kit and qualitative polymerase chain reaction (PCR) for Legionella pneumophila were negative. However, using deoxyribonucleic acid extracted from formalin-fixed paraffin-embedded lung tissue, PCR amplification of the ssrA gene of congeneric Legionella species yielded positive results. The results suggest that the cause of death was likely due to bacterial pneumonia caused by Legionella species., (© 2024 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

Background: Micrococcus antarcticus (M. antarcticus) is an aerobic Gram-positive spherical actinobacterium that was initially isolated from Chinese Great-Wall station in Antarctica in 2000. M. antarcticus was considered to be of low pathogenicity, no previous cases of human infection by this organism have been reported. Here we describe the first report with community-acquired pneumonia (CAP) caused by M. antarcticus., Case Presentation: An 87-year-old female was presented to the Central Hospital of Wuhan in November 2023 with a chief complaint of cough, sputum production, and chest tightness for 2 weeks. Microbial culture of the patient's bronchoalveolar lavage fluid (BALF) and identification of the isolates using Matrix-assisted laser desorption ionization/time of flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing revealed M. antarcticus infection. Combined with clinical symptoms, laboratory and imaging examination, the patient was diagnosed with CAP. Then cefoperazone/sulbactam and levofloxacin was administrated, the patient's condition was improved and she was discharged after a week after admission, no abnormalities were detected during a 5-month follow-up., Conclusions: This case highlights that M. antarcticus, first identified from a patient with CAP, is an extremely rare pathogenic microorganism. Clinicians should be aware of its potential as a pathogen in the diagnosis and treatment of CAP., (© 2024. The Author(s).)

Chlamydia psittaci pneumonia (CPP) exhibits similar characteristics as of COVID-19 with respect to clustering outbreaks and onset symptoms. This study is aimed at exploring the different clinical manifestations of both pneumonias to establish a simple nomogram to distinguish them. This multicenter, retrospective, case-control study compared two independent cohorts of patients with CPP or COVID-19. The risk factors of CPP were analyzed using multivariate logistic regression, which was used to establish the nomogram. Both patients with CPP and COVID-19 exhibited similar clinical symptoms. As compared to patients with COVID-19, a higher proportion of patients with CPP had nervous system symptoms. Patients with CPP had higher inflammatory indicators, creatine kinase, and lower lymphocyte and albumin. They also had lower proportions of ground-glass opacity and bilateral lung involvement than COVID-19 patients. Furthermore, patients with CPP had higher 30 day mortality as well as higher rates of severe pneumonia, septic shock, and ICU admission. Multivariate logistic regression showed that nervous system symptoms, lymphocytes, creatine kinase, bilateral lung lesions, and ground-glass opacity were risk factors for CPP. Incorporating these five factors, the nomogram achieved good concordance index of 0.989 in differentiating CPP from COVID-19, and had well-fitted calibration curves. Despite similar clinical characteristics, nervous system symptoms, lymphocyte, creatine kinase, lesions in bilateral lungs, and ground-glass opacity may help in differentiating the pneumonias. These were combined into a clinically useful nomogram for rapid and early identification of CPP to avoid misdiagnosis and help in the decision-making process., (© 2024. The Author(s).)

Background: Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide. Limited evidence is available on the most effective diagnostic approaches, management strategies, and long-term outcomes for CAP in patients who have undergone solid organ transplantation., Research Question: What is the acute and long-term morbidity and mortality after CAP in organ transplant recipients?, Study Design and Methods: We retrospectively analyzed hospitalizations for CAP in solid organ recipients at the largest German transplant center. The study included patients admitted between January 1, 2010, and May 31, 2021. The reported outcomes are in-hospital and 1-year mortality, risk of cardiovascular events during hospitalization and at 1 year, admission to the ICU, and risk of pneumonia with Pseudomonas aeruginosa. Multivariable binary logistic regression using stepwise forward selection was performed to determine predictive factors for pneumonia with P aeruginosa., Results: We analyzed data from 403 hospitalizations of 333 solid organ recipients. In > 60% of cases, patients had multiple comorbidities, with cardiovascular and chronic kidney disease being the most prevalent. More than one-half of the patients required oxygen supplementation after admission. In-hospital mortality (13.2%) and the death rate at 1 year postevent (24.6%) were higher than data reported from immunocompetent patients. We also observed high rates of acute cardiovascular events and events occurring 1 year after admission. Early blood cultures and bronchoscopy in the first 24 h significantly increased the odds of establishing an etiology. In our low-resistance setting, the burden of antimicrobial resistance was driven by bacteria from chronically colonized patients, mostly lung transplant recipients., Interpretation: This comprehensive analysis highlights the high morbidity associated with CAP after transplantation. It also emphasizes the need for prospective multicenter studies to guide evidence-based practices and improve outcomes for these vulnerable patients., Competing Interests: Financial/Nonfinancial Disclosures None declared., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Pneumonia continues to be one of the most frequent infectious syndromes and a relevant cause of death and health resources utilization. The OPENIN ("Optimización de procesos clínicos para el diagnóstico y tratamiento de infecciones") Group is composed of Infectious Diseases specialists and Microbiologists and aims at generating recommendations that can contribute to improve the approach to processes with high impact on the health system. Such task relies on a critical review of the available scientific evidence. The first Group meeting (held in October 2023) aimed at answering the following questions: Can we optimize the syndromic and microbiological diagnosis of pneumonia? Is it feasible to safely shorten the length of antibiotic therapy? And, is there any role for the immunomodulatory strategies based on the adjuvant use of steroids, macrolides or immunoglobulins? The present review summarizes the literature reviewed for that meeting and offers a series of expert recommendations., (Copyright © 2024 The Authors. Published by Elsevier España, S.L.U. All rights reserved.)

Background: An increased incidence of group A Streptococcus (GAS) infections has been observed in pediatric population post-COVID-19 pandemic. While the majority of reports refer to scarlet fever or invasive GAS disease, detailed data on pulmonary manifestations such as complicated community-acquired pneumonia (CAP) are scarce. The aim of this study was to assess the contribution of GAS to complicated CAP in children during the 2022/2023 infectious season., Methods: We retrospectively analyzed the etiology and clinical presentation of complicated CAP patients hospitalized in our tertiary care center in Warsaw, Poland, between August 2022 and May 2023., Results: Among 91 patients with complicated CAP, GAS was the dominant cause constituting 24.2% (22/91; 95% CI 15.8-34.3%) of the study group. 68.2% of GAS pneumonia patients presented symptoms of scarlet fever, and 27.3% had preceding or concurrent viral infection. GAS complicated CAP was associated with longer hospitalization, higher incidence of chest tube insertion, but shorter duration of chest tube drainage than complicated CAP of other etiology. Children with GAS complicated CAP had higher procalcitonin concentration (28.1 vs. 1.5 ng/dL; p<0.0001) and a lower platelets level (254.5 vs. 422 × 10 3 /μL; p = 0.0031) than those with non-GAS infection., Conclusions: GAS is currently the predominant pathogen of complicated CAP in children. Clinicians should be aware of the current epidemiological situation and a more severe course of GAS pneumonia in this age group, and should monitor patients presenting with symptoms of scarlet fever and preceding viral infection closely., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Infection Prevention and Control. Published by Elsevier Ltd. All rights reserved.)

Pediatric pneumonia can be severe and result in empyema. Next-generation sequencing (NGS) may broadly detect pathogens though, optimal timing and impact of sample type on diagnostic yield is unknown. This is a prospective, single-center pilot study of children aged 3 months through 17 years admitted to the PICU with a primary diagnosis of complicated pneumonia. Plasma, endotracheal, nasopharyngeal, and pleural fluid samples were collected at three time points during hospitalization. After nucleic acid extraction, combined libraries were enriched with an NGS enrichment panel kit (RPIP, Illumina), sequenced and quantitative organism detections were analyzed. NGS identified the same bacterial pathogen as traditional testing in all samples, regardless of antibiotic pre-treatment or time collected. Conventional culture methods only identified the pathogen reliably in invasively obtained pleural fluid or endotracheal aspirates. Future application of NGS may allow for non-invasive pathogen detection at a broader range of time points and more targeted antibiotic coverage., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Nicole Coufal reports financial support was provided by Illumina Inc. Rita Czako Stinnett reports a relationship with Illumina Inc that includes: employment. Nidhi Shah reports a relationship with Illumina Inc that includes: employment. Marta Mangifesta reports a relationship with Illumina Inc that includes: employment. Robert Schlaberg reports a relationship with Illumina Inc that includes: employment. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: Nephrotic syndrome (NS) is a common chronic kidney disease that is often accompanied by a state of immunodeficiency. Immunosuppression increases the risk of infections, with Pneumocystis jirovecii and Nocardia brasiliensis being two opportunistic pathogens that can cause severe infections in patients with compromised immune function. This study presents a case of a middle-aged male patient with NS concurrently infected with Pneumocystis jirovecii and Nocardia brasiliensis. It aims to synthesize the pertinent diagnostic approaches and treatment experiences. Notably, there have been no reported cases of NS occurring simultaneously with both Pneumocystis jirovecii pneumonia and Nocardia pneumonia., Case Presentation: A 58-year-old male farmer presented to the hospital with a one-week history of persistent fever, cough, and sputum production. His maximum body temperature was recorded at 39 °C, and he produced yellow viscous sputum. This patient had a one-year history of NS, managed with long-term oral corticosteroid and cyclophosphamide therapy. Admission chest computed tomography displayed interstitial changes in both lungs. After failing to detect any pathogens through routine etiological tests, we successfully identified Nocardia brasiliensis, Pneumocystis jirovecii, and Lodderomyces elongisporus using bronchoscopy-guided sputum samples through metagenomic next-generation sequencing (mNGS) technology. Subsequently, we initiated a combined treatment regimen for the patient using trimethoprim-sulfamethoxazole, meropenem, and moxifloxacin, which yielded remarkable therapeutic outcomes., Conclusion: The adoption and promotion of mNGS technologies have significantly resolved the difficulty in early pathogen detection, guiding clinicians from empirical to genomic diagnosis, achieving prevention before treatment, and thereby enhancing patient survival rates., (© 2024. The Author(s).)

Background: Chlamydia abortus, as a pathogen of atypical pneumonia, is rare in humans, especially in HIV infection patients., Case Presentation: We present the case of a 48-year-old man with a history of HIV infection who started high fever and developed pneumonia. The pathogen-targeted next-generation sequencing (ptNGS) results of bronchial lavage fluid showed Chlamydia abortus infection., Conclusion: This is the first report of Chlamydia abortus infection presented as atypical pneumonia in an AIDS patient., (© 2024. The Author(s).)

Background: The incidence of hypermucoviscous Klebsiella pneumoniae (hmvKp), which complicates community-acquired pneumonia, has been increasing recently. This study aimed to detect hypermucoviscous K. pneumoniae and determine its antimicrobial susceptibility pattern in adult patients with community-acquired pneumonia in Northwest Ethiopia., Methods: This cross-sectional study included 39 K. pneumoniae isolates identified by using Gram stain, culture, and biochemical tests from 312 adult patients with community-acquired pneumonia at the University of Gondar Comprehensive Specialized Referral Hospital from April to June 2021. The hypermucoviscous strains were identified by using the string test. Antimicrobial susceptibility testing was performed by using the Kirby-Bauer disk dif-fusion method. Data were entered by using EPI data version 4.6 and were analyzed by using SPSS version 20. A p-value ≤ 0.05 at a 95% confidence interval was considered statistically significant., Results: Overall, 35.9% (n = 14) of the 39 K. pneumoniae isolates were hypermucoviscous phenotype. The mean age of the hmvKp group was lower than of the cKp group (36.93 ± 12.573 vs. 53.52 ± 19.556 years, p = 0.007). All hmvKp isolates were resistant to amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole. Azithromycin resistance in the hmvKp strains was significantly higher than in the cKp group (p = 0.012)., Conclusions: This study demonstrates that the hmvKp phenotype causes community-acquired pneumonia and a full resistance to amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole. Antimicrobial resistance was higher in the hmvKp strain than in the classic strains. Further detection of resistance genes, capsular serotypes, hypermucoviscosity-related genes, and virulence genes is necessary.

Purpose: We describe a case of intraocular inflammation and palpable purpura in a patient with Pasteurella multocida pneumonia., Methods: A 75-year-old pseudophakic woman with type-2 diabetes and chronic obstructive pulmonary disease complained of lower limb palpable purpura and right vision loss of five-day duration. On admission, right visual acuity was hand motion. Slit-lamp examination disclosed severe conjunctival and ciliary injection, corneal oedema, 3-mm hypopyon with heavy fibrin accumulation and blood clots, and synechiae to the IOL., Results: Chest computed tomography revealed interstitial pneumonia. Sputum culture yielded P. multocida . Amoxicillin/clavulanic tablets (1 g × 3/daily) and topical and systemic steroids were given. Later on, fluorescein angiography showed multiple choroidal lesions bilaterally. With the above-mentioned therapy, there was full recovery of the skin, lung, and eye lesions., Conclusion: This report emphasizes that P. multocida infection should be considered in patients with intraocular inflammation, palpable purpura, and interstitial pneumonia. A multidisciplinary approach is necessary for a correct diagnosis and management.

Tropheryma whipplei is the causative agent of Whipple's disease, which is a rare multiorgan systemic disease. We report two cases of Tropheryma whipplei infection, all routine tests were negative and it was finally detected by mNGS. This may help clinicians increase awareness of the diagnosis and treatment of acute severe pneumonia and interstitial pneumonia caused by Tropheryma whipplei., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

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.)

Background: Pneumonia due to typical bacterial, atypical bacterial and viral pathogens can be difficult to clinically differentiate. Host response-based diagnostics are emerging as a complementary diagnostic strategy to pathogen detection., Methods: We used murine models of typical bacterial, atypical bacterial and viral pneumonia to develop diagnostic signatures and understand the host's response to these types of infections. Mice were intranasally inoculated with Streptococcus pneumoniae , Mycoplasma pneumoniae , influenza or saline as a control. Peripheral blood gene expression analysis was performed at multiple time points. Differentially expressed genes were used to perform gene set enrichment analysis and generate diagnostic signatures. These murine-derived signatures were externally validated in silico using human gene expression data. The response to S. pneumoniae was the most rapid and robust., Results: Mice infected with M. pneumoniae had a delayed response more similar to influenza-infected animals. Diagnostic signatures for the three types of infection had 0.94-1.00 area under the receiver operator curve (auROC). Validation in five human gene expression datasets revealed auROC of 0.82-0.96., Discussion: This study identified discrete host responses to typical bacterial, atypical bacterial and viral aetiologies of pneumonia in mice. These signatures validated well in humans, highlighting the conserved nature of the host response to these pathogen classes., 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.)

Introduction. The frequency of multidrug-resistant organisms (MDROs) in hospitals and the risk of delaying effective treatment result in the culture of respiratory secretions for nearly all patients with suspected pneumonia. Culture delays contribute to over prescribing and use of broader spectrum antibiotics. Gap statement. The need for improved rapid diagnostics for early assessment of suspected hospital pneumonia. Aim. To validate a new metric, enhanced Gram stain (EGS), to provide a rapid diagnostic test of high diagnostic accuracy that could be assessed in clinical trials of the use of antibiotics in suspected pneumonia. Methodology. Ninety-two residual lower respiratory samples previously tested by culture and Gram stain were re-tested by 16S ribosomal DNA real-time polymerase chain reaction (16S qPCR) and reported as a combined metric with Gram stain termed EGS. The EGS was assessed for diagnostic accuracy, standard performance measurements and correlation against culture. For samples with discordance between culture and EGS, 16S ribosomal DNA whole operon sequencing (16S rDNA WOS) was used for test resolution. An amended EGS (A-EGS was reassessed against culture. Results. Gram stain, 16S qPCR, EGS and A-EGS had respective diagnostic accuracies of 77.01 %, 82.76 %, 84.04 % and 94.19 %. The same platforms had respective correlation with culture of r = 0.67, r = 0.71, r = 0.81 and r = 0.89. EGS had the highest negative predictive value (NPV) of 93.18 % (81.99 %-97.62 %). Adding an 16S qPCR result is achievable in most routine laboratories and, combined with Gram stain, could improve early decision-making in patients with suspected hospital pneumonia. Conclusion. EGS could improve early decision-making in patients with suspected hospital pneumonia and could be assessed in clinical trials. The 16S rDNA WOS results in the A-EGS also supported the use of pathogen genomic sequencing in early decision making of suspected pneumonia.

Background: Legionella maceachernii pneumonia is a severe respiratory infection with low incidence but high mortality. However, the optimal treatment for this disease remains unclear. We report a case of successful treatment of Legionella maceachernii pneumonia, which is the first report of such a case in China., Case Presentation: An 87-year-old man with concomitant chronic obstructive pulmonary disease, liver cirrhosis, and history of left nephrectomy was diagnosed with Legionella maceachernii pneumonia using Dano-seq pathogen metagenomic testing. After two weeks of treatment with cefoperazone/sulbactam combined with quinolone antibiotics, the patient showed improvement and was discharged. The patient continued to take oral quinolone antibiotics for one week after discharge and recovered during outpatient follow-up., Conclusions: Dano-seq pathogen metagenomic testing can rapidly diagnose Legionella maceachernii pneumonia, and taking quinolone antibiotics is an effective treatment.

Background: Aeromonas dhakensis is associated with soft tissue infection, bacteremia and gastroenteritis. Involvement of respiratory system in adults is extremely rare. We report a case of fulminant pneumonia and bacteremia due to A. dhakensis in a patient without underlying diseases., Case Presentation: A 26-year-old man became ill suddenly with pneumonia after swimming in a river. Despite intensive support measures in the intensive care unit, he died 13 hours after admission and 4 days after his first symptoms. Autopsy showed abundant Gram-negative bacteria, massive inflammatory cell infiltration, edema, necrosis and hemorrhage in lung tissue. A. dhakensis was isolated from blood culture taken at admission and bronchoalveolar lavage fluid (BALF) after intubation. Moreover, A. dhakensis was also detected in lung tissue by metagenomic next-generation sequencing (mNGS) assay. The infection may have come from river water., Conclusion: In patients who develop a fulminant pneumonia after contacting an aquatic environment, A. dhakensis should be alerted and mNGS may aid in the detection of aquatic pathogens by being more sensitive and specific versus traditional bacterial culture., 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 Jiang, Zhao, Li, Gao, Zhang, Shu and Han.)

Background: Metastatic brain abscesses caused by Klebsiella pneumoniae are extremely rare but life-threatening conditions. To depict a unique case of the middle-aged hypertensive man with an unusual presentation of metastatic brain abscesses originating from a pleural abscess caused by Klebsiella pneumoniae and subsequently leading to loss of consciousness (LOC)., Case Report: A 52-year-old Iranian man with a history of hypertension presented to the emergency department with a five-day history of worsening cough, high-grade fever, shortness of breath, chest pain, fatigue, and a productive cough. Laboratory tests revealed leukocytosis, elevated C-reactive protein, and respiratory alkalosis. A chest computed tomography scan confirmed pneumonia, and a brain scan revealed multiple hypodense lesions. Despite antibiotic therapy, the patient's condition worsened, leading to confusion, disorientation, and loss of consciousness. Magnetic resonance imaging revealed multiple ring-enhancing lesions, suggesting an abscess formation. Bronchial washings and BAL samples confirmed a lower respiratory tract infection. Cultures from the bronchial washings grew Klebsiella pneumoniae., Conclusions: Metastatic brain abscesses caused by Klebsiella pneumoniae are exceedingly rare but life-threatening conditions. Timely diagnosis and effective antimicrobial treatment are critical for patient outcomes. This case underscores the significance of recognizing atypical presentations of bacterial infections, as early detection and appropriate management can significantly impact patient outcomes., (© 2024. The Author(s).)

In forensic cases, detailed identification of pneumonia is important. Our objective was to statistically determine the applicability of three interstitial lung disease (ILD) markers for forensic diagnosis using serum collected from dead bodies with various postmortem intervals (PMIs). We retrospectively analyzed the levels of postmortem serum Krebs von den Lungen-6 (KL-6) and pulmonary surfactant-associated proteins A and D (SP-A and SP-D) using 221 samples obtained during forensic autopsy at our facility from 2019 to 2023. We evaluated the diagnostic efficacy of ILD markers for various pneumonias against the pathological diagnosis, and examined the assessment of the severity of ILD. When comparing the ILD group with bacterial pneumonia (BP) versus the control group, there was a significant increase in KL-6 in the ILD group. When comparing the severe ILD (SILD) group with the mild ILD (MILD) group, there was a significant increase in KL-6 and SP-D in the SILD group. The optimal cutoff values for differentiating SILD were 607.0 U/mL for KL-6, 55.5 ng/mL for SP-A, and 160.0 ng/mL for SP-D, and the sensitivity/specificity (%) of KL-6, SP-A, and SP-D for SILD were 84.1/95.2, 55.6/85.7, and 66.7/74.6, respectively. This is the first study to examine KL-6 in postmortem serum in forensic medicine. By analyzing dead bodies with various PMIs, our results confirmed statistically that postmortem serum KL-6 specifically detects ILD, postmortem serum SP-A has high sensitivity to lung injury, and postmortem serum SP-D is potentially useful in assessing the severity of ILD., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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.

Pulmonary infection due to Mycobacterium abscessus complex (MABC) usually occurs in children with underlying risk factors including cystic fibrosis (CF), chronic lung disease, and immunocompromised status, but rarely in immunocompetent children without underlying lung disease, especially in infants. We present a case of MABC pulmonary disease (MABC-PD) in an otherwise healthy 53-day-old male infant with one week of cough and respiratory distress. Computed tomography showed multiple masses across both lungs. Isolated mycobacteria from his bronchoalveolar lavage fluid were identified as MABC. We describe our complete evaluation, including immunodeficiency evaluation incorporating whole exome sequencing and our therapeutic process given complicated susceptibility pattern of the M. abscessus isolate, and review literature for MABC-PD in immunocompetent children. The infant was successfully treated through prolonged treatment with parenteral Amikacin, Cefoxitin, Linezolid, and Clarithromycin, combined with inhaled Amikacin., Competing Interests: Declaration of competing interest No potential conflict of interest relevant to this article was reported., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Legionella pneumonia is one of the most severe types of atypical pneumonia, impairing multiple organ systems, posing a threat to life. Diagnosing Legionella pneumonia is challenging due to difficulties in culturing the bacteria and limitations in immunoassay sensitivity and specificity., Case Presentation: This paper reports a rare case of sepsis caused by combined infection with Legionella pneumophila and Fusobacterium necrophorum, leading to respiratory failure, acute kidney injury, acute liver injury, myocardial damage, and electrolyte disorders. In addition, we systematically reviewed literature on patients with combined Legionella infections, analyzing their clinical features, laboratory results and diagnosis., Conclusions: For pathogens that require prolonged incubation periods and are less sensitive to conventional culturing methods, metagenomic next-generation sequencing (mNGS) can be a powerful supplement to pathogen screening and plays a significant role in the auxiliary diagnosis of complex infectious diseases., (© 2024. The Author(s).)

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.

Pneumonia is a common nosocomial complication in transplant patients. Stenotrophomonas maltophilia is recognized as a common cause and is typically seen in immunocompromised and critically ill patients. S. maltophilia, a nonfermenting gram-negative rod, ranks as the third most common nosocomial pathogen, following Pseudomonas aeruginosa and Acinetobacter. The bacteria are frequently found in environmental sources and are prevalent in healthcare facilities, including in tap water faucets, shower outlets, air-cooling systems, intravenous fluids, catheters, dialysis machines, and oxygen humidifiers. This bacterium possesses the ability to rapidly form biofilms, enabling it to colonize new surfaces in less than 24 hours. While S. maltophilia generally exhibits low virulence, there remains uncertainty among many clinicians regarding whether it is merely a colonizer or the primary cause of infection. Although S. maltophilia infections are rare in immunocompetent individuals, the species is increasingly recognized as an opportunistic pathogen in vulnerable populations such as those with cystic fibrosis, cancer, and other conditions leading to immunosuppression. S. maltophilia now recognized as a causative agent in various clinical syndromes, primarily affecting the lungs and bloodstream. We present a case of S. maltophilia-associated lung infection in a kidney transplant recipient, emphasizing the significance of underlying diseases and associated signs and symptoms., Competing Interests: Declaration of competing interest All the authors declare no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Procalcitonin (PCT) is a useful biomarker in humans in the identification of bacterial respiratory infections., Objectives: The aim of this study was to investigate the utility of serum PCT measurements as a diagnostic biomarker in canine bacterial lower respiratory tract diseases., Methods: PCT concentrations were measured in serum samples with an ELISA method previously validated for dogs. All dogs underwent thorough clinical examinations, and the diagnosis of respiratory disease was based on clinical and laboratory findings, diagnostic imaging, as well as cytology and bacterial culture of respiratory samples. PCT concentrations between different cohorts of dogs were compared with an ANOVA-model., Results: Sixty-two privately owned dogs with respiratory diseases, 25 with bacterial pneumonia (BP), 17 with bacterial bronchitis caused by Bordetella bronchiseptica (BB), and 20 with chronic bronchitis (CB) as well as 44 healthy controls were included in the study. Serum PCT concentrations in dogs with bacterial respiratory diseases (BP mean 51.8 ng/L ± standard deviation [SD] 40.6 ng/L and BB mean 61.4 ng/L ± SD 35.3 ng/L) were not significantly different when compared with dogs with a non-bacterial respiratory disease (CB mean 89.7 ± SD 73.5 ng/L) or healthy dogs (mean 51.0 ng/L ± SD 37.5 ng/L, p > .05 in all comparisons)., Conclusions: These results indicate that despite being a valuable diagnostic, prognostic, and follow-up marker in humans with pneumonia, serum PCT concentrations are not elevated in dogs with bacterial respiratory diseases and, therefore, cannot be used as a diagnostic biomarker in dogs., (© 2024 The Authors. Veterinary Clinical Pathology published by Wiley Periodicals LLC on behalf of American Society for Veterinary Clinical Pathology.)

Burkholderia semiarida was previously identified solely as a plant pathogen within the Burkholderia cepacia complex. We present a case in China involving recurrent pneumonia attributed to B. semiarida infection. Of note, the infection manifested in an immunocompetent patient with no associated primary diseases and endured for >3 years.

Introduction: Q fever, a zoonotic disease caused by Coxiella burnetii (C. burnetii), presents diagnostic challenges due to its clinical and radiological nonspecificity, which often mimics community-acquired pneumonia, coupled with the limitations of traditional diagnostic methods. Metagenomic next-generation sequencing (mNGS) has become an indispensable tool in clinical diagnostics for its high-throughput pathogen identification capabilities. Herein, we detail a case of acute Q fever pneumonia diagnosed with mNGS., Case Presentation: The patient exhibited symptoms of fever, cough, expectoration, and diarrhea for three days, with the pathogen undetected in initial laboratory assessments. Bronchoscopy and bronchoalveolar lavage (BAL) were conducted, leading to the identification of C. burnetii in the lavage fluid via mNGS. Consequently, the patient was promptly initiated on a treatment regimen of 100 mg doxycycline, administered orally every 12 hours., Results: Post-treatment, the patient's temperature normalized, and a full recovery was observed. The follow-up chest CT scan revealed complete resolution of the right lower lobe consolidation., Conclusions: The clinical presentation of Q fever pneumonia lacks specificity, making diagnosis based solely on symptoms and imaging challenging. mNGS offers a superior alternative for identifying elusive or rarely cultured pathogens., Competing Interests: No Conflict of Interest is declared, (Copyright (c) 2024 Bin Liu, Peng Huang, Yanchao Liang, Shuangbo Liu, Fangwei Chen, Xiping Luo, Tengjuan Xu, Bo Xie.)

Background: Community-acquired pneumonia (CAP) is a common and serious condition that can be caused by a variety of pathogens. However, much remains unknown about how these pathogens interact with the lower respiratory commensals, and whether any correlation exists between the dysbiosis of the lower respiratory microbiota and disease severity and prognosis., Methods: We conducted a retrospective cohort study to investigate the composition and dynamics of sputum microbiota in patients diagnosed with CAP. In total, 917 sputum specimens were collected consecutively from 350 CAP inpatients enrolled in six hospitals following admission. The V3-V4 region of the 16 S rRNA gene was then sequenced., Results: The sputum microbiota in 71% of the samples were predominately composed of respiratory commensals. Conversely, 15% of the samples demonstrated dominance by five opportunistic pathogens. Additionally, 5% of the samples exhibited sterility, resembling the composition of negative controls. Compared to non-severe CAP patients, severe cases exhibited a more disrupted sputum microbiota, characterized by the highly dominant presence of potential pathogens, greater deviation from a healthy state, more significant alterations during hospitalization, and sparser bacterial interactions. The sputum microbiota on admission demonstrated a moderate prediction of disease severity (AUC = 0.74). Furthermore, different pathogenic infections were associated with specific microbiota alterations. Acinetobacter and Pseudomonas were more abundant in influenza A infections, with Acinetobacter was also enriched in Klebsiella pneumoniae infections., Conclusion: Collectively, our study demonstrated that pneumonia may not consistently correlate with severe dysbiosis of the respiratory microbiota. Instead, the degree of microbiota dysbiosis was correlated with disease severity in CAP patients., (© 2024. The Author(s).)

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.)

Lower respiratory tract infections (LRTI) are still burdened by considerable morbidity and mortality. Rapid and appropriate treatment imply knowledge of the underlying causative pathogen; while it is tempting to offer broad spectrum antibiotics, Antimicrobial Stewardship Practices invite a judicious use of the latter, especially when bacteria are not the cause. However, the epidemiology shifts to multidrug resistant (MDR) pathogens that require optimization of molecules in order to provide optimal treatment. Novel methods requiring direct sample result testing such as the Biofire Pneumonia (PN) panel have recently been made available on the market. Syndromic testing may hence provide support in the diagnosis of LRTI. There is paucity of data concerning experiences in high MDR settings, and even less concerning the performance of these panels in pediatric settings with moderate MDR prevalence. Our study highlights the optimal sensitivity and importance of support from such methods in settings burdened by MDR presence and where fast and appropriate therapy is mandatory.

With the use of metagenomic next-generation sequencing, patients diagnosed with Whipple pneumonia are being increasingly correctly diagnosed. We report a series of 3 cases in China that showed a novel pattern of movable infiltrates and upper lung micronodules. After treatment, the 3 patients recovered, and lung infiltrates resolved.

Background: Prevotella heparinolytica is a Gram-negative bacterium that is commonly found in the oral, intestinal, and urinary tracts. It has been extensively studied in lower respiratory tract infections in horses, which has heparinolytic activity and can secrete heparinase and further induces virulence factors in cells and causes disease. However, no such cases have been reported in humans., Case Presentation: A 58-year-old male patient from China presented to the respiratory clinic in Suzhou with a productive cough producing white sputum for 20 days and fever for 3 days. Prior to this visit, a chest computed tomography scan was conducted, which revealed multiple patchy nodular opacities in both lungs. On admission, the patient presented with a temperature of 38.1 °C and a pulse rate of 110 beats per minute. Despite routine anti-infective treatment with moxifloxacin, his temperature fluctuated and the treatment was ineffective. The patient was diagnosed with Prevotella heparinolytica infection through metagenomic next-generation sequencing. Therefore, the antibiotics were switched to piperacillin-tazobactam in combination with ornidazole, which alleviated his symptoms; 1 week after discharge, the patient returned to the clinic for a follow-up chest computed tomography, and the opacities on the lungs continued to be absorbed., Conclusion: Prevotella heparinolytica is an opportunistic pathogen. However, it has not been reported in human pneumonia. In refractory pneumonia, measures such as metagenomic next-generation sequencing can be used to identify pathogens and help guide antibiotic selection and early support., (© 2024. The Author(s).)

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).)