Primary Site Of Infection Research Articles

Sepsis Epidemiology and Outcomes in Pediatric Intensive Care Unit of Alkhadra Hospital, Tripoli, Libya

Despite the various interventions and therapies that have been implemented to improve the quality of life for children with sepsis, the prevalence and death rates continue to increase. This issue is a major public health problem that requires the continuous improvement of the guidelines and the identification of new strategies. The aim of the study was to identify the prevalence and outcomes of severe sepsis among children admitted to the Pediatric Intensive Care Unit (PICU). This study was conducted in PICU of Alkhadra Hospital in 2023 as a hospital-based retrospective study. All children who were admitted to the PICU from 2017 to 2022 were included. Data was collected from hospital file records, which included the following: age of patient, gender, comorbidities of patients, and source of admission; origin of sepsis; type of PICU admission; primary site of infection; organ dysfunction present at screening; and patient outcomes. Of the 1284 total admissions to the PICU, 128 patients (9.96%) met the definition of sepsis. Most patients (78.9%) were less than 6 years old. Respiratory problems and congenital malformations were the most common co-morbidities, with reported rates of 18.8% and 10.2%, respectively. The emergency department was the most common source of admission (67.2%). Nearly all patients had good overall performance, whereas (21.1%) of the patients were in a coma. 77.3% discharged during the study, and 22.7% died. Although decreasing the incidence through preventive measures is ideal, early recognition and treatment of sepsis will decrease both short- and long-term complications and related mortality of at-risk infants and children.

Spontaneous brain abscess formation: challenge of a shifting pathogen spectrum over the last 21 years – a single center experience

BackgroundSpontaneous intracerebral abscess formation is a rare condition presenting with a disabling sequela. The origin of infection can either be primary or secondary to an infection at another location. The site of primary infection - due to the proximity, often the oral cavity, the sinuses, and the orbit - determines the causative pathogens. Treatment often combines surgical and antimicrobial therapies. To determine the microbiology and respective changes and treatment outcome, we performed this retrospective monocentric cohort study of patients requiring surgical treatment of brain abscesses.MethodsPatients undergoing surgical treatment of a primary intracranial abscess between January 2000 and January 2021 in the Department of Neurosurgery, Freiburg University Hospital were included. Demographic, clinical and imaging data were extracted from patients’ medical records and databases. Treatment approaches were also analyzed, and surgical therapy and antibiotic therapy were reported. Outcome was assessed by the modified Rankin score (mRS) and was dichotomized into good (mRS 0–3) and poor (mRS 4–6) outcome.ResultsWe included 65 patients with spontaneous intracerebral abscess that were treated with neurosurgical intervention at our institution. Analysis of the causative pathogens showed an increasing dominance of rare pathogens such as fungi, parasites, mycobacteria and anaerobes. Outcome measured by the mRS was similar from 2005 to 2021.ConclusionsThe pathogen spectrum of spontaneous intracerebral abscess at our institution is shifting with rarer pathogens being increasingly detected. This retrospective analysis highlights the need for microbiological diagnosis and of combined surgical and antibiological treatment.

Clinical characteristics and bloodstream infection pathogens by gram-negative bacteria in different aged adults: A retrospective study.

This study aims to determine the characteristics and distribution of pathogenic bacteria in bloodstream infections (BSIs) by gram-negative bacteria in adults. One hundred seventy-one adult patients with BSIs who were treated at the Affiliated Hospital of Chengde Medical College between January 2018 and January 2020 were included in this study. The patients were assigned to the young- and middle-aged group and elderly group based on age. General patient data were analyzed. More elderly patients had BSIs and gram-negative bacteria than young- and middle-aged patients. The incidence of underlying diseases in elderly patients was significantly higher than the young- and middle-aged patients (P < .01). The composition of Brucella spp. was significantly different between the elderly group and young- and middle-aged group (P < .05). There were significantly more gallbladder infections in the elderly group than the young- and middle-aged group, and significantly fewer elderly patients had no definite infection sites than the young- and middle-aged group (P < .05). The incidence of complications and in-hospital mortality in the elderly group was higher than the young- and middle-aged group (P < .05). BSIs caused by gram-negative bacteria mainly involved elderly patients. BSIs were characterized by complications and a poor prognosis, as well as pathogenic bacteria and primary infection sites.

Analysis of Nirmatrelvir Entry into Pulmonary Lining Fluid in Patients with COVID-19: A Unique Perspective to Explore and Understand the Target Plasma Concentration of 292 ng/mL in Antiviral Activity.

Currently, the applicant has chosen a target plasma trough concentration for nirmatrelvir, which is adjusted to 292 ng/mL based on the drug's molecular weight (499.54 Daltons), its binding to human plasma proteins (69%), and the in vitro antiviral EC90 value (181 nM). However, the current exposure-effect relationships (ER) analysis of viral load in patients enrolled in the EPIC-HR study has not revealed clinically significant trends in the ER. Given that the lungs are the primary site of COVID-19 infection, we aim to further understand this exposure relationship by exploring and analyzing the penetration characteristics of nirmatrelvir in the lungs. To explore and understand the target plasma concentration of 292 ng/mL in antiviral activity. We identified all critically ill patients with coronavirus disease 2019 who received nirmatrelvir/ritonavir treatment in the respiratory intensive care unit of Changhai hospital between January 2023 and October 2023. Samples of plasma and bronchoalveolar lavage fluid were obtained at pre-dose trough concentrations after administration of nirmatrelvir (NMV). The relationship between NMV levels in plasma and the epithelial lining fluid (ELF) was assessed by determining concentrations of NMV. There was a significant relationship between NMV levels in plasma and ELF (ELF = 0.4976*PLASMA- 204; R = 0.96), with a correlation whose slope (0.4976) suggested that the blood-to-ELF ratio of drug penetration was 2:1. A negative value from the equation indicates that NMV requires to reach baseline concentration to penetrate the ELF. The relationship between NMV levels in plasma and ELF with low permeability and a negative baseline value suggests that the target plasma concentration of 292 ng/mL is insufficient for antiviral activity. This study provides a unique perspective to explore and understand no clinically meaningful trend of exposure-response relationships in patients enrolled in EPIC-HR.

HCMV strain- and cell type-specific alterations in membrane contact sites point to the convergent regulation of organelle remodeling.

Viruses are ubiquitous entities that infect organisms across the kingdoms of life. While viruses can infect a range of cells, tissues, and organisms, this aspect is often not explored in cell culture analyses. There is limited information about which infection-induced changes are shared or distinct in different cellular environments. The prevalent pathogen human cytomegalovirus (HCMV) remodels the structure and function of subcellular organelles and their interconnected networks formed by membrane contact sites (MCSs). A large portion of this knowledge has been derived from fibroblasts infected with a lab-adapted HCMV strain. Here, we assess strain- and cell type-specific alterations in MCSs and organelle remodeling induced by HCMV. Integrating quantitative mass spectrometry, super-resolution microscopy, and molecular virology assays, we compare infections with lab-adapted and low-passage HCMV strains in fibroblast and epithelial cells. We determine that, despite baseline proteome disparities between uninfected fibroblast and epithelial cells, infection induces convergent changes and is remarkably similar. We show that hallmarks of HCMV infection in fibroblasts, mitochondria-endoplasmic reticulum (ER) encapsulations and peroxisome proliferation, are also conserved in infected epithelial and macrophage-like cells. Exploring cell type-specific differences, we demonstrate that fibroblasts rely on endosomal cholesterol transport while epithelial cells rely on cholesterol from the Golgi. Despite these mechanistic differences, infections in both cell types result in phenotypically similar cholesterol accumulation at the viral assembly complex. Our findings highlight the adaptability of HCMV, in that infections can be tailored to the initial cell state by inducing both shared and unique proteome alterations, ultimately promoting a unified pro-viral environment.IMPORTANCEHuman cytomegalovirus (HCMV) establishes infections in diverse cell types throughout the body and is connected to a litany of diseases associated with each of these tissues. However, it is still not fully understood how HCMV replication varies in distinct cell types. Here, we compare HCMV replication with lab-adapted and low-passage strains in two primary sites of infection, lung fibroblasts and retinal epithelial cells. We discover that, despite displaying disparate protein compositions prior to infection, these cell types undergo convergent alterations upon HCMV infection, reaching a more similar cellular state late in infection. We find that remodeling of the subcellular landscape is a pervasive feature of HCMV infection, through alterations to both organelle structure-function and the interconnected networks they form via membrane contact sites. Our findings show how HCMV infection in different cell types induces both shared and divergent changes to cellular processes, ultimately leading to a more unified state.

Prevalence of nosocomial infections and their influencing factors in a tertiary general hospital in Qingdao.

The goals of this study were to analyze the situation and dynamic change trend of the prevalence of nosocomial infections among inpatients, to investigate the use of antibiotics, and to provide evidence-based support for the development of targeted prevention and control measures for nosocomial infections and rational use of antibiotics. The nosocomial infection surveillance system was utilized to conduct a cross-sectional survey of nosocomial infections of all inpatients, followed by a statistical evaluation of the 5-year survey results. The average prevalence of nosocomial infections over the 5-year period (2017 to 2021) was 2.28%, and the incidence rate per case was 2.42%. The lower respiratory tract was the primary site of infection, followed by the urinary tract. The most prevalent pathogens of nosocomial infections were Gram-negative bacteria (GNB), including Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli; and the main strains of Gram-positive bacteria (GPB) included Staphylococcus aureus and Enterococcus faecium. The use of antibiotics accounted for 41.31% on average; and the proportion of antibiotics used for treatment was 84.99% on average. The average rate of pathogen examination was 51.09%, indicating an increasing trend (χ2 = 44.196, p < 0.001). The average prevalence of nosocomial infections over the past five years was 2.28% in this tertiary general hospital. Although the prevalence rate of nosocomial infections in the hospital was relatively low, it is necessary to strengthen the measures for prevention and control of infections of the lower respiratory tract, urinary tract, and surgical incision.

Epstein-Barr virus infection induces tissue-resident memory T cells in mucosal lymphoid tissues.

EBV contributes to around 2% of all tumors worldwide. Simultaneously, more than 90% of healthy human adults persistently carry EBV without clinical symptoms. In most EBV carriers, it is thought that virus-induced tumorigenesis is prevented by cell-mediated immunity. Specifically, memory CD8+ T cells recognize EBV-infected cells during latent and lytic infection. Using a symptomatic primary infection model, similar to infectious mononucleosis (IM), we found EBV-induced CD8+ tissue resident memory T cells (TRMs) in mice with a humanized immune system. These human TRMs were preferentially established after intranasal EBV infection in nasal-associated lymphoid tissues (NALT), equivalent to tonsils, the primary site of EBV infection in humans. They expressed canonical TRM markers, including CD69, CD103, and BLIMP-1, as well as granzyme B, CD107a, and CCL5. Despite cytotoxic activity and cytokine production ex vivo, these TRMs demonstrated reduced CD27 expression and proliferation and failed to control EBV viral loads in the NALT during infection, although effector memory T cells (TEMs) controlled viral titers in spleen and blood. Overall, TRMs are established in mucosal lymphoid tissues by EBV infection, but primarily, systemic CD8+ T cell expansion seems to control viral loads in the context of IM-like infection.

Community-acquired sepsis in the medical intensive care unit: An experience from a lower-middle-income country.

To determine microbiological pathogens and in-hospital mortality in patients admitted with communityacquired sepsis to the intensive care unit in a tertiary-care setting in a low- and middle-income country. The retrospective, observational study was conducted at the medical intensive care unit of a large tertiary care hospital in Karachi, and comprised data from January 1 to December 31, 2019 of patients with community-acquired sepsis who were assessed using the Sepsis-3 criteria. Data was compared between survivors and non-survivors, and independent factors associated with in-hospital mortality were identified. Data was analysed using SPSS 23. Of the 135 patients with mean age 49.8±18.0 years, 91(67.4%) were males and 44(32.6%) were females. The most common primary site of infection was the respiratory tract 63(46.7%). Multi-drug-resistant organisms were isolated in 39 (28.9%) patients. In-hospital mortality was noted in 52(38.5%) cases, while there were 83(61.5%) survivors. Serum levels of lactate and bicarbonate as well as urine output, fungal pathogens, septic shock and sequential organ failure assessment score were significantly associated with mortality (p<0.05). Clinical and microbiological spectrum of community-acquired sepsis in a low- and middle-income country was found to be different from other regions of the world. Clinicians should keep these differences in mind while managing these critically ill patients.

Identifying Gaps in the International Consensus Case Definitions for Invasive Aspergillosis: A Review of Clinical Cases Not Meeting These Definitions.

International consensus definitions for invasive aspergillosis (IA) in research are rigorous, yet clinically significant cases are often excluded from clinical studies for not meeting proven/probable IA case definitions. To better understand reasons for the failure to meet criteria for proven/probable infection, we herein review 47 such cases for their clinical and microbiological characteristics and outcomes. Data on 47 cases that did not meet consensus IA definitions but were deemed significant were derived from a retrospective, observational, multicenter survey of 382 presumed IA cases across Australasia, of which findings of 221 proven/probable infections were recently published. The clinical, microbiological, and radiologic characteristics of these cases were analyzed. Mortality outcomes were compared with those of 221 proven/probable cases. Of 47 cases studied, 15 lacked classical host factors; 22 exhibited only a single positive Aspergillus polymerase chain reaction result; 7 lacked typical IA radiologic findings on chest computed tomography; and 3 had borderline galactomannan optical density indices (<1.0 but ≥0.5) in bronchoalveolar lavage fluid. The median age of patients was 61 years (IQR, 52-68); 34 were male (72%). Seven patients (15%) required intensive care admission. All patients had lung as the primary site of infection. Antifungal treatment was initiated in 42 patients (89%). All-cause 90-day mortality was 33%, similar to the 30% mortality in the comparative cohort (n = 221). Our findings highlight the limitations of current consensus definitions for IA. Notably, the mortality of patients not meeting these definitions was similar to that of patients with proven/probable IA. Further studies, especially of patients with a single positive Aspergillus polymerase chain reaction result and those without host factors, are needed to determine if future consensus definitions may benefit from modifications.

Analysis of risk factors for onset of acquired Serratia marcescens infection in neonatal intensive care unit

To analyze the clinical characteristics of critically ill neonates in the neonatal intensive care unit (NICU) who acquired Serratia marcescens infection for onset or colonization, and to explore the risk factors contributing to the onset of Serratia marcescens infection. A retrospective case-control study was conducted by collecting clinical data from NICU neonates at the Women and Children's Hospital of Ningbo University between January 2017 and December 2023. Forty-four neonates with clinical signs and/or symptoms consistent with Serratia marcescens infection, and with Serratia marcescens isolated from specimens, would be enrolled as the infection onset group, while 45 neonates who tested positive for Serratia marcescens in rectal and/or pharyngeal cultures during the same period, but had no clinical signs or infection symptoms, were enrolled as the colonization control group. The distribution of bacteria in the neonates infected with Serratia marcescens was observed, and clinical data were subjected to univariate and binary multivariate Logistic regression analyses for screening the independent risk factors for onset of acquired Serratia marcescens infection in NICU. During the 7-year period, 5 972 neonates were admitted to the NICU, of which 297 developed hospital-acquired infections. Among these, 44 neonates were identified with Serratia marcescens infection, accounting for 14.8% of hospital-acquired infections. During the same period, a total of 45 neonates were diagnosed with the colonization of Serratia marcescens, but did not develop any symptoms. The primary infection sites of the neonates in both the colonization control group and infection onset group were respiratory tract, accounting for 86.7% (39/45) and 43.2% (19/44), respectively. The highest rate of infection in the infection onset group was respiratory tract (43.2%), followed by bloodstream infection [29.6% (13/44)], intracranial infection [15.9%, (7/44)], intestinal infection [6.8% (3/44)], and urinary tract infection [4.5% (2/44)]; no deaths were reported. In addition to respiratory tract infection, 13.3% (6/45) of the neonates in the colonization control group had intestinal infection, and no pathogenic bacteria was detected in their blood, cerebrospinal fluid, or urine. Univariate analysis showed that compared with the colonization control group, the neonates in the infection onset group had lower gestational ages [days: 28.5 (26.9, 30.0) vs. 32.0 (30.1, 34.6), P < 0.01], lower birth weights and proportion of probiotic usage [birth weights (kg): 1.20 (0.96, 1.44) vs. 1.75 (1.45, 2.23), probiotic usage: 29.5% (13/44) vs. 57.8% (26/45), both P < 0.01], longer length of NICU stay and duration of antibiotic usage [length of NICU stay (days): 65.11±23.00 vs. 40.31±20.04, duration of antibiotic usage (days): 23.09±9.57 vs. 11.80±7.19, both P < 0.01], and higher proportions of invasive procedures such as mechanical ventilation > 3 days and central venous catheterization > 7 days [mechanical ventilation > 3 days: 61.4% (27/44) vs. 20.0% (9/45), central venous catheterization > 7 days: 81.8% (36/44) vs. 28.9% (13/45), both P < 0.01], indicating that these factors were associated with Serratia marcescens infection onset acquired in NICU. Binary multivariate Logistic regression analysis showed that a birth weight of ≤ 1.5 kg [odds ratio (OR) = 5.745, 95% confidence interval (95%CI) was 1.345-24.549, P = 0.018], a length of NICU stay > 45 days (OR = 3.642, 95%CI was 1.102-12.041, P = 0.034), duration of antibiotic usage (OR = 0.871, 95%CI was 0.799-0.949, P = 0.002), non-usage of probiotics (OR = 3.191, 95%CI was 1.058-9.627, P = 0.039), and invasive procedures such as mechanical ventilation > 3 days (OR = 5.302, 95%CI was 1.510-18.619, P = 0.009), and central venous catheterization > 7 days (OR = 3.818, 95%CI was 1.103-13.212, P = 0.034) were independent risk factors for the onset of NICU-acquired Serratia marcescens infection. The incidence of NICU-acquired Serratia marcescens infection is high. Low birth weight, prolonged length of NICU stay, long-term antibiotic usage, and invasive treatments are independent risk factors for the onset of NICU-acquired Serratia marcescens infection. Oral probiotics may be a new method for preventing onset of NICU-acquired Serratia marcescens infection.

Positively charged mesoporous silica nanocarriers loaded with arbidol: A novel effective nano antiviral system against nervous necrosis virus

Viral nervous necrosis (VNN) caused by nervous necrosis virus (NNV) poses a significant threat to the global aquaculture industry, leading to substantial economic losses. In this study, we evaluated the anti-NNV activity of arbidol both in vitro and in vivo. Treatment with arbidol at a concentration of 10.48 μM effectively inhibited NNV-induced cytopathic effects in GF-1 cells, and the half-maximal inhibitory concentration (IC50) of arbidol against NNV was determined to be 7.915 μM. To improve drug delivery to the central nervous system, the primary site of NNV infection, we developed positively charged mesoporous silica nanocarriers (CMSNs) loaded with arbidol (CMSNs-ARB). Compared to unmodified mesoporous silica nanocarriers, CMSNs exhibited significantly higher uptake in GF-1 cells and zebrafish brains, indicating their potential to cross the blood-brain barrier (BBB) and deliver drugs more efficiently. In vivo experiments revealed that arbidol administration improved the survival rate of juvenile fish infected with NNV. Additionally, the use of CMSNs as a drug carrier further enhanced the larval survival rate by 13 % compared to the arbidol-only treatment group. These results demonstrate the potent anti-NNV activity of arbidol and highlight the potential of CMSNs as an effective drug delivery system to control fish viral diseases in aquaculture.

Rotational Thromboelastometric Profile in Early Sepsis: A Prospective Cohort Study.

Coagulation abnormalities are common in sepsis patients and are associated with increased mortality. This study aimed to assess the hemostatic profile of sepsis patients using rotational thromboelastometry (ROTEM) and to find the ROTEM parameters best predicting short-term mortality. We conducted a prospective analysis of consecutive sepsis patients hospitalized in the intensive care unit. The inclusion criteria were diagnosis of sepsis or septic shock and pro-calcitonin concentration >0.5 ng mL-1. Clinical, standard laboratory, and ROTEM analyses were performed. The study group comprised 38 (49%) males and 40 (51%) females. Median Sequential Organ Failure Assessment (SOFA) score was 8 (interquartile range IQR 5-11) points. The most common primary sites of infection were pneumonia (n = 27/35%), intra-abdominal (n = 27/35%), urinary tract infection (n=20/26%), and others (n = 4/6%). The following parameters evaluating fibrinogen function were outside the reference range: clotting time (CT), clot amplitude (A) at 10 and 20 min, and maximal clot firmness (MCF). Out of 78 patients, 28 (36%) died in the intensive care unit. Significant differences between survivors and non-survivors of sepsis were present for the ROTEM parameters assessing fibrinolytic activity. ROTEM in the early phase of sepsis reveals increased coagulation mediated through the function of fibrinogen. Non-survivors showed slightly lower fibrinolytic activity than survivors; however, it was still within test reference values. The highest predicting value was obtained by a model incorporating, among others, extrinsic coagulation pathway fibrinolytic parameters.

Multiple impacts of the COVID-19 pandemic and antimicrobial stewardship on antimicrobial resistance in nosocomial infections: an interrupted time series analysis.

The emergency response to the COVID-19 pandemic may disrupt hospital management activities of antimicrobial resistance (AMR). This study aimed to determine the changing AMR trend over the period in China when stringent COVID-19 response measures were implemented. This retrospective study was conducted in a designated hospital for COVID-19 patients in Guangzhou, China from April 2018 to September 2021. The prevalence of 13 antimicrobial-resistant bacteria was compared before and after the COVID-19 responses through Chi-square tests. Interrupted time series (ITS) models on the weekly prevalence of AMR were established to determine the changing trend. Controlled ITS models were performed to compare the differences between subgroups. A total of 10,134 isolates over 1,265 days were collected. And antimicrobial-resistant strains presented in 38.6% of the testing isolates. The weekly AMR prevalence decreased by 0.29 percentage point (95% CI [0.05-0.80]) after antimicrobial stewardship (AMS) policy, despite an increase in the prevalence of penicillin-resistant Streptococcus pneumoniae (from 0/43 to 15/43, p < 0.001), carbapenem-resistant Escherichia coli (from 20/1254 to 41/1184, p = 0.005), and carbapenem-resistant Klebsiella pneumoniae (from 93/889 to 114/828, p = 0.042). And the changing trend did not vary by gender (male vs. female), age (<65 vs. ≥65 years), service setting (outpatient vs. inpatient), care unit (ICU vs. non-ICU), the primary site of infection (Lung vs. others), and Gram type of bacteria (positive vs. negative). The response to COVID-19 did not lead to an increase in overall AMR; however, it appears that management strategy on the prudent use of antimicrobials likely contributed to a sizable long-term drop. The frequency of several multidrug-resistant bacteria continues to increase after the COVID-19 epidemic. It is crucial to continue to monitor AMR when COVID-19 cases have surged in China after the relaxation of restriction measures.

Neutrophilic Myocarditis: Insights from a Forensic Centre's Retrospective Study.

Neutrophilic myocarditis often stems from bacterial or fungal infections, and it is typically detectable through blood cultures or analyses of the primary infection site. However, research specifically addressing the morphological features of acute myocarditis in complex sepsis cases is scarce, with existing studies primarily dating back to the pre-antibiotic era. This study constitutes a retrospective and descriptive analysis encompassing 22 forensic cases. We collected data from forensic reports emphasising clinical details, disease history, gross observations, and histopathological findings. The results show that using positive-air-pressure ventilation could be related to cardiac inflammation (45.45%, 10/22). Despite large-spectrum antibiotic therapy, the blood samples were positive for Staphylococcus aureus (MRSA strain), Klebsiella pneumoniae (ESBL strain), Acinetobacter baumannii, and Pseudomonas aeruginosa. Colonies developed in the myocardium of 36% of the patients (8/22), where 4 of them had septic emboli. Fungal myocarditis accompanied bacterial infections (2/8) and were unsuspected clinically. Background changes, such as interstitial fibrosis and arteriosclerosis, were associated with a greater degree of inflammation and septic embolism. Neutrophilic myocarditis in patients with emerging sepsis is linked to fatal virulent infections, where bacteria and/or fungi contaminate and impair the myocardium syncytium. Prolonged hospitalisation and positive-air-pressure ventilation may be a risk factor for this condition and needs further research.

Ceftazidime-Avibactam as a Salvage Treatment for Severely Infected Immunosuppressed Children.

Multidrug-resistant Gram-negative bacteria (MDR-GNB) are becoming increasingly common around the world, with carbapenems frequently serving as a last resort but being threatened by the growing incidence of carbapenemase-producing bacteria. Ceftazidime-avibactam (CAZ/AVI) is a potential agent against MDR-GNB but with limited clinical experience, particularly in critically ill immunosuppressed children. This study analyzed the use of CAZ/AVI as salvage treatment in severely infected immunosuppressed children from September 2019 to July 2022. Patients with confirmed GNB infection who received CAZ/AVI were matched with patients who received other antibiotics. Twenty-five critically ill immunosuppressed children treated with CAZ/AVI were included. The majority had hematologic diseases. All patients presented with sepsis in all 30 courses. Septic shock presented in 36.7% of these courses. The primary sites of infection included bloodstream infection (20.0%), skin and skin structure infection (20.0%), intra-abdominal infection (13.3%) and hospital-acquired pneumonia (10.0%). Twelve of the 25 (48.0%) patients had positive microbiological cultures, mainly Pseudomonas aeruginosa and Klebsiella pneumoniae, including 5 carbapenem-resistant GNB-infected cases. Fifteen (50.0%) courses presented clinical improvement. For the initial course of each patient, the clinical response rate of the GNB recovered group was significantly higher than that of the group without GNB recovery (66.7% vs 23.1%, P = 0.047). The 14-day and 30-day mortality rates were 24.0% and 28.0%, respectively, which were significantly correlated with the absence of GNB recovery (P = 0.004 and 0.024, respectively) and hospital-acquired pneumonia as the primary site of infection (P = 0.001 and 0.006, respectively). There was no significant difference in major outcomes between patients who received CAZ/AVI and matched patients who received other antibiotics. CAZ/AVI could be considered a salvage strategy for immunosuppressed children with confirmed GNB infection. Caution should be taken when CAZ/AVI is applied to these patients in the absence of GNB recovery.

Randomised, double-blind, controlled phase 1 trial of the candidate tuberculosis vaccine ChAdOx1-85A delivered by aerosol versus intramuscular route

A BCG booster vaccination administered via the respiratory mucosa may establish protective immune responses at the primary site of Mycobacterium tuberculosis infection. The primary objective of this trial was to compare the safety and immunogenicity of inhaled versus intramuscular administered ChAdOx1-85A. We conducted a single-centre, randomised, double-blind, controlled phase 1 study (Swiss National Clinical Trials Portal number SNCTP000002920). After a dose-escalation vaccination in nine BCG-vaccinated healthy adults, a dose of 1×1010 vp of ChAdOx1-85A was administered to twenty BCG-vaccinated adults that were randomly allocated (1:1) into two groups: aerosol ChAdOx1-85A with intramuscular saline placebo or intramuscular ChAdOx1-85A with aerosol saline placebo, using block randomisation. A control group of ten BCG-naïve adults received aerosol ChAdOx1-85A at the same dose. Primary outcomes were solicited and unsolicited adverse events (AEs) up to day 16 post-vaccination and Serious AEs (SAEs) up to 24 weeks; secondary outcomes were cell-mediated and humoral immune responses in blood and bronchoalveolar lavage (BAL) samples. Both vaccination routes were well tolerated with no SAEs. Intramuscular ChAdOx1-85A was associated with more local AEs (mostly pain at the injection site) than aerosol ChAdOx1-85A. Systemic AEs occurred in all groups, mainly fatigue and headaches, without differences between groups. Respiratory AEs were not different between BCG-vaccinated groups. Aerosol ChAdOx1-85A vaccination induced Ag85A BAL and systemic cellular immune responses with compartmentalisation of the immune responses: aerosol ChAdOx1-85A induced stronger BAL cellular responses, particularly IFNγ/IL17+CD4+T cells; intramuscular ChAdOx1-85A induced stronger systemic cellular and humoral responses. Inhaled ChAdOx1-85A was well-tolerated and induced lung mucosal and systemic Ag85A-specific T-cell responses. These data support further evaluation of aerosol ChAdOx1-85A and other viral vectors as a BCG-booster vaccination strategy.

Design of Experiment (DoE) Approach for Developing Inhalable PLGA Microparticles Loaded with Clofazimine for Tuberculosis Treatment.

Tuberculosis (TB) is an airborne bacterial infection caused by Mycobacterium tuberculosis (M. tb), resulting in approximately 1.3 million deaths in 2022 worldwide. Oral therapy with anti-TB drugs often fails to achieve therapeutic concentrations at the primary infection site (lungs). In this study, we developed a dry powder inhalable formulation (DPI) of clofazimine (CFZ) to provide localized drug delivery and minimize systemic adverse effects. Poly (lactic acid-co-glycolic acid) (PLGA) microparticles (MPs) containing CFZ were developed through a single emulsion solvent evaporation technique. Clofazimine microparticles (CFZ MPs) displayed entrapment efficiency and drug loading of 66.40 ± 2.22 %w/w and 33.06 ± 1.45 µg/mg, respectively. To facilitate pulmonary administration, MPs suspension was spray-dried to yield a dry powder formulation (CFZ SD MPs). Spray drying had no influence on particle size (~1 µm), zeta potential (-31.42 mV), and entrapment efficiency. Solid state analysis (PXRD and DSC) of CFZ SD MPs studies demonstrated encapsulation of the drug in the polymer. The drug release studies showed a sustained drug release. The optimized formulation exhibited excellent aerosolization properties, suggesting effective deposition in the deeper lung region. The in vitro antibacterial studies against H37Ra revealed improved (eight-fold) efficacy of spray-dried formulation in comparison to free drug. Hence, clofazimine dry powder formulation presents immense potential for the treatment of tuberculosis with localized pulmonary delivery and improved patient compliance.

Gene Regulatory Network Analysis of Post-Mortem Lungs Unveils Novel Insights into COVID-19 Pathogenesis.

The novel coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged as one of the most significant global health crises in recent history. The clinical characteristics of COVID-19 patients have revealed the possibility of immune activity changes contributing to disease severity. Nevertheless, limited information is available regarding the immune response in human lung tissue, which is the primary site of infection. In this study, we conducted an extensive analysis of lung tissue to screen for differentially expressed miRNAs and mRNAs in five individuals who died due to COVID-19 and underwent a rapid autopsy, as well as seven control individuals who died of other causes unrelated to COVID-19. To analyze the host response gene expression, miRNA microarray and Nanostring's nCounter XT gene expression assay were performed. Our study identified 37 downregulated and 77 upregulated miRNAs in COVID-19 lung biopsy samples compared to the controls. A total of 653 mRNA transcripts were differentially expressed between the two sample types, with most transcripts (472) being downregulated in COVID-19-positive specimens. Hierarchical and PCA K-means clustering analysis showed distinct clustering between COVID-19 and control samples. Enrichment and network analyses revealed differentially expressed genes important for innate immunity and inflammatory response in COVID-19 lung biopsies. The interferon-signaling pathway was highly upregulated in COVID-19 specimens while genes involved in interleukin-17 signaling were downregulated. These findings shed light on the mechanisms of host cellular responses to COVID-19 infection in lung tissues and could help identify new targets for the prevention and treatment of COVID-19 infection.

Characteristics of RNA Stabilizer RNApro for Peripheral Blood Collection.

Peripheral blood is the most practical tissue for human immune system gene expression profiling because it is easily accessible, whereas the site of primary infection in certain diseases may not be easily accessible. Due to the ex vivo instability of RNA transcripts, a key challenge in the gene expression analysis of blood samples is the rapid sample handling and stabilization of the mRNA by adding an RNA preservative (PAXgeneTM Blood RNA Tubes, TempusTM Blood RNA tubes, RNAlater Stabilization Reagent, RNAgard® Blood Tubes). BioMole (Turin, Italy) has developed a novel blood stabilizer, called RNApro, in which RNA is stabilized during phlebotomy and sample storage. In this study, RNApro performance intended as RNA yield, integrity, and stability was evaluated. Our results show that blood samples stored at -80 °C and re-extracted after 7 years show no differences in terms of quantity, quality, and amplificability. The samples in the RNAlater stabilization solution can be stored at room temperature for up to one week or at 4 °C for up to one month. Similar results can also be observed for PAXgene tubes, Tempus tubes, and RNAgard tubes. In agreement with these data, the RNApro stabilization solution preserves the RNA from degradation for up to 1 month at 4 °C and 1 week at room temperature. RNApro can be stored indifferently at -80, -20, 4 °C, or room temperature for up to 2 months after, and then could be stored at -80 °C for up to seven years. In summary, our study is the first to analyze the performance of an RNA stabilizer called RNApro. We can conclude that several studies have shown significant differences in gene expression analysis when the sample was preserved in different RNA stabilizers. Therefore, it is desirable to standardize the method of nucleic acid conservation when comparing data from transcriptomic analyses.

Host Immune Response Modulation in Avian Coronavirus Infection: Tracheal Transcriptome Profiling In Vitro and In Vivo.

Infectious bronchitis virus (IBV) is a highly contagious Gammacoronavirus causing moderate to severe respiratory infection in chickens. Understanding the initial antiviral response in the respiratory mucosa is crucial for controlling viral spread. We aimed to characterize the impact of IBV Delmarva (DMV)/1639 and IBV Massachusetts (Mass) 41 at the primary site of infection, namely, in chicken tracheal epithelial cells (cTECs) in vitro and the trachea in vivo. We hypothesized that some elements of the induced antiviral responses are distinct in both infection models. We inoculated cTECs and infected young specific pathogen-free (SPF) chickens with IBV DMV/1639 or IBV Mass41, along with mock-inoculated controls, and studied the transcriptome using RNA-sequencing (RNA-seq) at 3 and 18 h post-infection (hpi) for cTECs and at 4 and 11 days post-infection (dpi) in the trachea. We showed that IBV DMV/1639 and IBV Mass41 replicate in cTECs in vitro and the trachea in vivo, inducing host mRNA expression profiles that are strain- and time-dependent. We demonstrated the different gene expression patterns between in vitro and in vivo tracheal IBV infection. Ultimately, characterizing host-pathogen interactions with various IBV strains reveals potential mechanisms for inducing and modulating the immune response during IBV infection in the chicken trachea.