The Oxysterol-Binding Protein Cycle: Burning Off PI(4)P to Transport Cholesterol.

To maintain an asymmetric distribution of ions across membranes, protein pumps displace ions against their concentration gradient by using chemical energy. Here, we describe a functionally analogous but topologically opposite process that applies to the lipid transfer protein (LTP) oxysterol-binding protein (OSBP). This multidomain protein exchanges cholesterol for the phosphoinositide phosphatidylinositol 4-phosphate [PI(4)P] between two apposed membranes. Because of the subsequent hydrolysis of PI(4)P, this counterexchange is irreversible and contributes to the establishment of a cholesterol gradient along organelles of the secretory pathway. The facts that some natural anti-cancer molecules block OSBP and that many viruses hijack the OSBP cycle for the formation of intracellular replication organelles highlight the importance and potency of OSBP-mediated lipid exchange. The architecture of some LTPs is similar to that of OSBP, suggesting that the principles of the OSBP cycle-burning PI(4)P for the vectorial transfer of another lipid-might be general.

The Drosophila tumour suppressor Lgl and Vap33 activate the Hippo pathway through a dual mechanism.

The tumour suppressor, Lethal (2) giant larvae [Lgl; also known as L(2)gl], is an evolutionarily conserved protein that was discovered in the vinegar fly Drosophila, where its depletion results in tissue overgrowth and loss of cell polarity. Lgl links cell polarity and tissue growth through regulation of the Notch and the Hippo signalling pathways. Lgl regulates the Notch pathway by inhibiting V-ATPase activity via Vap33. How Lgl regulates the Hippo pathway was unclear. In this current study, we show that V-ATPase activity inhibits the Hippo pathway, whereas Vap33 acts to activate Hippo signalling. Vap33 physically and genetically interacts with the actin cytoskeletal regulators RtGEF (Pix) and Git, which also bind to the Hippo protein (Hpo) and are involved in the activation of the Hippo pathway. Additionally, we show that the ADP ribosylation factor Arf79F (Arf1), which is a Hpo interactor, is involved in the inhibition of the Hippo pathway. Altogether, our data suggest that Lgl acts via Vap33 to activate the Hippo pathway by a dual mechanism: (1) through interaction with RtGEF, Git and Arf79F, and (2) through interaction and inhibition of the V-ATPase, thereby controlling epithelial tissue growth.

Glycolipid transfer protein knockout disrupts vesicle trafficking to the plasma membrane.

The glycolipid transfer protein (GLTP) has been linked to many cellular processes aside from its best-known in vitro function as a lipid transport protein. It has been proposed to act as a sensor and regulator of glycosphingolipid homeostasis in cells. Furthermore, through its previously determined interaction with the endoplasmic reticulum membrane protein VAP-A (vesicle-associated membrane protein-associated protein A), GLTP may also be involved in facilitating vesicular transport in cells. In this study, we characterized the phenotype of CRISPR/Cas9-mediated GLTP KO HeLa cells. We showed that motility, three-dimensional growth, and cellular metabolism were all altered by GLTP knockout. Expression of a GLTP mutant incapable of binding VAP disrupted cell spheroid formation, indicating that the GLTP-VAP interaction is linked to cellular adhesion, cohesion, and three-dimensional growth. Most notably, we found evidence that GLTP, through its interaction with VAP-A, affects vesicular trafficking, marking the first cellular process discovered to be directly impacted by a change in GLTP expression.

The yeast VAPs Scs2 and Scs22 are required for NVJ integrity and micronucleophagy.

Microautophagy degrades cargos in the vacuole by direct engulfment of the vacuolar membrane. Micronucleophagy selectively degrades a portion of the nucleus in budding yeast. The vacuole contacts the nucleus via the nucleus-vacuole junction (NVJ), and in micronucleophagy a portion of the nucleus containing nucleolar proteins is made to protrude into the vacuole at the NVJ, followed by abscission and degradation. Microautophagy and micronucleophagy are induced by inactivation of target of rapamycin complex 1 (TORC1) protein kinase after nutrient starvation. Here, we show that the VAMP-associated proteins (VAPs) Scs2 and its paralog Scs22 are required for NVJ integrity and micronucleophagic degradation of nucleolar proteins. On the other hand, nucleolar dynamics prerequisite for micronucleophagy were not impaired in VAP mutant cells. Finally, yeast VAPs were critical for viability during prolonged nutrient starvation. This study sheds light on the emerging role of VAP in adaptation in responses to nutrient starvation.

Prior carbapenem exposure increases the incidence of ventilator-associated pneumonia in critically Ill children.

BACKGROUND: Prior antibiotic exposure has been identified as a risk factor for VAP occurrence, making it a growing concern among clinical practitioners. But there is a lack of systematic research on the types of antibiotics and the duration of exposure that influence VAP occurrence in children at current. METHODS: We retrospectively reviewed 278 children admitted to the Pediatric Intensive Care Unit (PICU) and underwent invasive mechanical ventilation (MV) between January 2020 and December 2022. Of these, 171 patients with MV duration ≥ 48 h were included in the study, with 61 of them developing VAP (VAP group) and the remaining 110 as the non-VAP group. We analyzed the relationship between early antibiotic exposure and VAP occurrence. RESULTS: The incidence of VAP was 21.94% (61/278). The VAP group had significantly longer length of hospital stay (32.00 vs. 20.00 days, p<0.001), PICU stay(25.00 vs. 10.00 days, p<0.001), and duration of mechanical ventilation(16.00 vs. 6.00 days, p<0.001) compared to the non-VAP group. The mortality in the VAP group was significantly higher than that in the non-VAP group (36.07% vs. 21.82%, p = 0.044). The VAP group had a significantly higher rate of carbapenem exposure (65.57% vs. 41.82%, p = 0.003) and duration of usage (9.00 vs. 5.00 days, p = 0.004) than the non-VAP group. Vancomycin and/or linezolid exposure rates (57.38% vs. 40.00%, p = 0.029) and duration (8 vs. 4.5 days, p = 0.010) in the VAP group were significantly higher than that in the non-VAP group, either. Multivariate logistic regression analysis identified the use of carbapenem (≥ 7 days) (OR = 5.156, 95% CI: 1.881-14.137, p = 0.001), repeated intubation (OR = 3.575, 95% CI: 1.449-8.823, p = 0.006), and tracheostomy (OR = 5.767, 95% CI:1.686-19.729, p = 0.005) as the independent risk factors for the occurrence of VAP, while early intravenous immunoglobulin (IVIG) was a protective factor against VAP (OR = 0.426, 95% CI: 0.185-0.98, p = 0.045). CONCLUSION: Prior carbapenem exposure (more than 7 days) was an independent risk factor for the occurrence of VAP. For critically ill children, reducing carbapenem use and duration as much as possible should be considered.

Bundle care approach to reduce device associated infections in post-living-donor-liver transplantation in a tertiary care hospital, Egypt.

BACKGROUND: Device-associated infections (DAIs) are a significant cause of morbidity following living donor liver transplantation (LDLT). We aimed to assess the impact of bundled care on reducing rates of device-associated infections. METHODS: We performed a before-and-after comparative study at a liver transplantation facility over a three-year period, spanning from January 2016 to December 2018. The study included a total of 57 patients who underwent LDLT. We investigated the implementation of a care bundle, which consists of multiple evidence-based procedures that are consistently performed as a unified unit. We divided our study into three phases and implemented a bundled care approach in the second phase. Rates of pneumonia related to ventilators [VAP], bloodstream infections associated with central line [CLABSI], and urinary tract infections associated with catheters [CAUTI] were assessed throughout the study period. Bacterial identification and antibiotic susceptibility testing were performed using the automated Vitek-2 system. The comparison between different phases was assessed using the chi-square test or the Fisher exact test for qualitative values and the Kruskal-Wallis H test for quantitative values with non-normal distribution. RESULTS: In the baseline phase, the VAP rates were 73.5, the CAUTI rates were 47.2, and the CLABSI rates were 7.4 per one thousand device days (PDD). During the bundle care phase, the rates decreased to 33.3, 18.18, and 4.78. In the follow-up phase, the rates further decreased to 35.7%, 16.8%, and 2.7% PDD. The prevalence of Klebsiella pneumonia (37.5%) and Methicillin resistance Staph aureus (37.5%) in VAP were noted. The primary causative agent of CAUTI was Candida albicans, accounting for 33.3% of cases, whereas Coagulase-negative Staph was the predominant organism responsible for CLABSI, with a prevalence of 40%. CONCLUSION: This study demonstrates the effectiveness of utilizing the care bundle approach to reduce DAI in LDLT, especially in low socioeconomic countries with limited resources. By implementing a comprehensive set of evidence-based interventions, healthcare systems can effectively reduce the burden of DAI, enhance infection prevention strategies and improve patient outcomes in resource-constrained settings.

Molecular characterization of NDM and OXA-48-like-producing Klebsiella pneumoniae ST16 and hypervirulent ST337 clone among two patients; a case report.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections are a major public health problem, requiring the use of last-resort antibiotics such as colistin. However, there is concern regarding the emergence of isolates resistant to this agent. The report describes two patients with urinary tract infection (UTI) and ventilator-associated pneumonia (VAP) infection caused by CRKP strains. The first case was a 23-year-old male with UTI caused by a strain of ST16 co-harboring blaCTX-M, blaTEM, blaSHV, blaNDM, blaOXA-48-like genes. The second case was a 39-year-old woman with VAP due to hypervirulent ST337-K2 co-harboring blaSHV, blaNDM, blaOXA-48-like, iucA, rmpA2 and rmpA. The patients' general condition improved after combination therapy with colistin (plus meropenem and rifampin, respectively) and both of them recovered and were discharged from the hospital. This study highlights the necessary prevention and control steps to prevent the further spread of CRKP strains should be a priority in our hospital.

Risk factors for ventilator-associated lower respiratory tract infection in COVID-19, a retrospective multicenter cohort study in Sweden.

BACKGROUND: Ventilator-associated lower respiratory tract infections (VA-LRTI) increase morbidity and mortality in intensive care unit (ICU) patients. Higher incidences of VA-LRTI have been reported among COVID-19 patients requiring invasive mechanical ventilation (IMV). The primary objectives of this study were to describe clinical characteristics, incidence, and risk factors comparing patients who developed VA-LRTI to patients who did not, in a cohort of Swedish ICU patients with acute hypoxemic respiratory failure due to COVID-19. Secondary objectives were to decipher changes over the three initial pandemic waves, common microbiology and the effect of VA-LTRI on morbidity and mortality. METHODS: We conducted a multicenter, retrospective cohort study of all patients admitted to 10 ICUs in southeast Sweden between March 1, 2020 and May 31, 2021 because of acute hypoxemic respiratory failure due to COVID-19 and were mechanically ventilated for at least 48 h. The primary outcome was culture verified VA-LRTI. Patient characteristics, ICU management, clinical course, treatments, microbiological findings, and mortality were registered. Logistic regression analysis was conducted to determine risk factors for first VA-LRTI. RESULTS: Of a total of 536 included patients, 153 (28.5%) developed VA-LRTI. Incidence rate of first VA-LRTI was 20.8 per 1000 days of IMV. Comparing patients with VA-LRTI to those without, no differences in mortality, age, sex, or number of comorbidities were found. Patients with VA-LRTI had fewer ventilator-free days, longer ICU stay, were more frequently ventilated in prone position, received corticosteroids more often and were more frequently on antibiotics at intubation. Regression analysis revealed increased adjusted odds-ratio (aOR) for first VA-LRTI in patients treated with corticosteroids (aOR 2.64 [95% confidence interval [CI]] [1.31-5.74]), antibiotics at intubation (aOR 2.01 95% CI [1.14-3.66]), and days of IMV (aOR 1.05 per day of IMV, 95% CI [1.03-1.07]). Few multidrug-resistant pathogens were identified. Incidence of VA-LRTI increased from 14.5 per 1000 days of IMV during the first wave to 24.8 per 1000 days of IMV during the subsequent waves. CONCLUSION: We report a high incidence of culture-verified VA-LRTI in a cohort of critically ill COVID-19 patients from the first three pandemic waves. VA-LRTI was associated with increased morbidity but not 30-, 60-, or 90-day mortality. Corticosteroid treatment, antibiotics at intubation and time on IMV were associated with increased aOR of first VA-LRTI.

Ventilator-associated pneumonia caused by a new-found opportunistic fungal pathogen-Myceliophthora heterothallica: a case report.

BACKGROUND: Myceliophthora heterothallica belonging to Myceliophthora is considered as an environmental fungus and has not been reported to be pathogenic or colonizing in recent literature. The present case firstly reports a ventilation-associated pneumonia caused by Myceliophthora heterothallica among the aged adult. CASE PRESENTATION: A 67-years-old Asian female patient suffering from a sudden disturbance of consciousness for 3 h was admitted to our hospital. Cardiac arrest occurred during emergency transport, and sinus rhythm was restored after cardiopulmonary resuscitation. Invasive mechanical ventilation was given to this patient for respiratory failure. After mechanical ventilation, the lung CT images showed multiple cuneiform nodules arranging subpleural accompanying with ground-glass opacity. On the 5th day of mechanical ventilation, Myceliophthora heterothallica was cultured from endotracheal aspirates. Two methods, namely automatic microbial identification system and internal transcribed spacer sequencing were employed to identify this fungus. The present case firstly uncovered the colonization ability and pathogenicity of Myceliophthora heterothallica in the respiratory tract. After 28d of treatment with piperacillin-tazobactam, this patient weaned from the ventilator and recovered from consciousness with lung infection disappearance. CONCLUSIONS: This is the first case report of ventilation-associated pneumonia in the aged patient caused by Myceliophthora heterothallica. This current case is worth for the clinical diagnosis and treatment of Myceliophthora heterothallica infection, and also enriches new pathogenic species found of thermothelomyces species.

Exploring Ventilator-Associated Pneumonia: Microbial Clues and Biomarker Insights from a Retrospective Study.

Background and Objectives: Ventilator-associated pneumonia (VAP) is a common complication in critically ill patients receiving mechanical ventilation. The incidence rates of VAP vary, and it poses significant challenges due to microbial resistance and the potential for adverse outcomes. This study aims to explore the microbial profile of VAP and evaluate the utility of biomarkers and illness severity scores in predicting survival. Materials and Methods: A retrospective cohort study was conducted involving 130 patients diagnosed with VAP. Microbial analysis of bronchoalveolar lavage (BAL) fluid, as well as measurements of C-reactive protein (CRP) and procalcitonin (PCT) levels, were performed. Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were calculated to assess illness severity. Statistical analyses were conducted to determine correlations and associations. Results: The study revealed that Klebsiella pneumoniae (K. pneumoniae) (50.7%) and Pseudomonas aeruginosa (P. aeruginosa) (27.69%) were the most identified microorganisms in VAP cases. SOFA (p-value < 0.0001) and APACHE II (p-value < 0.0001) scores were effective in assessing the severity of illness and predicting mortality in VAP patients. Additionally, our investigation highlighted the prognostic potential of CRP levels (odds ratio [OR]: 0.980, 95% confidence interval [CI] 0.968 to 0.992, p = 0.001). Elevated levels of CRP were associated with reduced survival probabilities in VAP patients. Conclusion: This study highlights the microbial profile of VAP and the importance of biomarkers and illness severity scores in predicting survival. Conclusions: The findings emphasize the need for appropriate management strategies to combat microbial resistance and improve outcomes in VAP patients.

Antimicrobial resistance pattern in aerobic bacteria isolated from endotracheal aspirate in ventilator-associated pneumonia: Ten years observation from a tertiary care hospital.

Background and Aims: Ventilator-associated pneumonia (VAP) is a nosocomial infection associated with high morbidity and mortality. This study was undertaken to monitor the trend of the demographical details, comorbid conditions, bacterial etiological agents, and their antibiogram causing VAP in adults in the year 2008, 2013 and 2018. Material and Methods: A retrospective study conducted at the Department of Microbiology, Hospital Infection control and Quality Control at a tertiary care teaching hospital. All the adult patients with more than 48 h of the mechanical ventilator with endotracheal intubation with Clinical Pulmonary infection Score >6 with suspicion of VAP were included in the study at a difference of 5 years, i.e., 2008, 2013, and 2018. Results: A total of 338 patients were included in the study, of which males accounted for more than two-third of the patients studied. Nearly 45% of the patients belonged to geriatric (>60 years) age group. The most common comorbid conditions were chronic obstructive pulmonary disease, hypertension and diabetes mellitus. Among the gram-negative isolates, Klebsiella pneumoniae, Acinetobacter species, and Pseudomonas aeruginosa were the most common. There is an emergence of resistance to most commonly administered antimicrobial agents like aminoglycosides, levofloxacin, piperacillin/tazobactum, and carbapenems during the study period. Conclusion: This is a ten-year study on the antibiotic resistance pattern of organisms causing VAP. As far as the authors are aware, this is the first study addressing the pattern of change in drug resistance in the organisms causing VAP over a decade. The emergence of multi-drug resistant (MDR) MDR pathogens, especially in intensive care unit (ICU), is a great concern for the intensivist and infection control physicians. Preventive measures need to be undertaken to control the spread of these pathogens to the patients in the ICU.

Analysis of small EV proteomes reveals unique functional protein networks regulated by VAP-A.

Extracellular vesicles (EVs) influence cell phenotypes and functions via protein, nucleic acid, and lipid cargoes. EVs are heterogeneous, due to diverse biogenesis mechanisms that remain poorly understood. Our previous study revealed that the endoplasmic reticulum (ER) membrane contact site (MCS) linker protein vesicle associated protein associated protein A (VAP-A) drives biogenesis of a subset of RNA-enriched EVs. Here, we examine the protein content of VAP-A-regulated EVs. Using label-free proteomics, we identified down- and upregulated proteins in small EVs (SEVs) purified from VAP-A knockdown (KD) colon cancer cells. Gene set enrichment analysis (GSEA) of the data revealed protein classes that are differentially sorted to SEVs dependent on VAP-A. Search Tool for the Retrieval of Reciprocity Genes (STRING) protein-protein interaction network analysis of the RNA-binding protein (RBP) gene set identified several RNA functional machineries that are downregulated in VAP-A KD SEVs, including ribosome, spliceosome, mRNA surveillance, and RNA transport proteins. We also observed downregulation of other functionally interacting protein networks, including cadherin-binding, unfolded protein binding, and ATP-dependent proteins.

In situ artificial contact sites (ISACS) between synthetic and endogenous organelle membranes allow for quantification of protein-tethering activities.

Membrane contact sites are specialized areas where the membranes of two distinct organelles are physically connected and allow for the exchange of molecules and for signaling processes. Understanding the mechanisms whereby proteins localize to and function in these structures is of special interest; however, methods allowing for reconstitution of these contact sites are few and only based on synthetic membranes and recombinant proteins. Here, we devised a strategy to create in situ artificial contact sites between synthetic and endogenous organelle membranes. Liposomes functionalized with a peptide containing a two phenylalanines in an acidic tract (FFAT) motif were added to adherent cells whose plasma membrane was perforated. Confocal and super-resolution microscopy revealed that these liposomes associated with the endoplasmic reticulum via the specific interaction of the FFAT motif with endoplasmic reticulum-resident vesicle-associated membrane protein-associated proteins. This approach allowed for quantification of the attachment properties of peptides corresponding to FFAT motifs derived from distinct proteins and of a protein construct derived from steroidogenic acute regulatory protein-related lipid transfer domain-3. Collectively, these data indicate that the creation of in situ artificial contact sites represents an efficient approach for studying the membrane-tethering activity of proteins and for designing membrane contact site reconstitution assays in cellular contexts.

VAP-SCRN1 interaction regulates dynamic endoplasmic reticulum remodeling and presynaptic function.

In neurons, the continuous and dynamic endoplasmic reticulum (ER) network extends throughout the axon, and its dysfunction causes various axonopathies. However, it remains largely unknown how ER integrity and remodeling modulate presynaptic function in mammalian neurons. Here, we demonstrated that ER membrane receptors VAPA and VAPB are involved in modulating the synaptic vesicle (SV) cycle. VAP interacts with secernin-1 (SCRN1) at the ER membrane via a single FFAT-like motif. Similar to VAP, loss of SCRN1 or SCRN1-VAP interactions resulted in impaired SV cycling. Consistently, SCRN1 or VAP depletion was accompanied by decreased action potential-evoked Ca2+ responses. Additionally, we found that VAP-SCRN1 interactions play an important role in maintaining ER continuity and dynamics, as well as presynaptic Ca2+ homeostasis. Based on these findings, we propose a model where the ER-localized VAP-SCRN1 interactions provide a novel control mechanism to tune ER remodeling and thereby modulate Ca2+ dynamics and SV cycling at presynaptic sites. These data provide new insights into the molecular mechanisms controlling ER structure and dynamics, and highlight the relevance of ER function for SV cycling.

Relation between red blood cell distribution width and 30-day in-hospital mortality of patients with ventilator-associated pneumonia.

BACKGROUND: Epidemiological studies have demonstrated an association between red blood cell distribution width (RDW) and the prognosis of pneumonia-associated diseases. However, prognostic value of RDW in patients with ventilator-associated pneumonia (VAP) has yet to be investigated. This study aimed to explore the association between RDW and in-hospital mortality in VAP patients and explore predictive value of RDW for VAP patients. METHODS: This retrospective cohort study included 1,543 VAP patients from the Medical Information Mart for Intensive Care IV database 2008-2019. The primary outcome was considered to 30-day in-hospital mortality of VAP patients in this study. Non-high RDW level group was defined as <15 %, and high RDW level group as ≥15%. The possible confounding factors were screened by least absolute shrinkage and selection operator regression. Univariate and multivariate COX regression analyses were used for the assessment on the association of RDW and 30-day in-hospital mortality in VAP patients. We also performed subgroup analyses. Furthermore, a comparative analysis of RDW and sequential organ failure assessment (SOFA) score and simplified acute physiology score II (SAPS II) were performed by receiver operating characteristic (ROC) curves. RESULTS: The 30-day in-hospital mortality of VAP patients was approximately 19.05%. After adjusting all confounding factors, high RDW was associated with 30-day in-hospital mortality among VAP patients by using non-high RDW as the reference [hazard ratio (HR) =1.29, 95% confidence interval (CI): 1.01-1.63]. Additionally, the relationship was also robust in several populations, such as patients were younger than 60 years, or had not a history of congestive heart failure, or had a history of sepsis, or had not received renal replacement therapy, or had a duration of mechanical ventilation for more than 7 days. The result of ROC indicated that RDW had a better prognostic value in predicting 30-day in-hospital mortality for VAP patients than SOFA score and SAPS II score. CONCLUSION: High RDW level is associated with an increased 30-day in-hospital mortality. The RDW is a promising biomarker in predicting 30-day in-hospital mortality for patients admitted to the ICU, regardless of VAP.

Unintended impact of COVID-19 pandemic on the rate of catheter related nosocomial infections and incidence of multiple drug resistance pathogens in three intensive care units not allocated to COVID-19 patients in a large teaching hospital.

BACKGROUND: The prevalence of resistant hospital infections in the intensive care unit (ICU) increases mortality and antibiotic resistance. COVID-19 pandemic may have unintended impact on nosocomial infections (NI) and the prevalence of resistant microorganism. METHODOLOGY: The present non-interventional study was performed by a pre and a post survey each lasting 8 months before (March-October 2019) and after (March-October 2020) the onset of COVID-19 pandemic in three ICU's, not allocated to COVID-19 patients, in Nemazee Hospital, Shiraz, Iran. The rates of the following nosocomial infections were compared at pre- and post-pandemic period: ventilator associated pneumonia (VAP), central line associated blood stream infection (CLABSI), catheter-associated urinary tract infections (CAUTI) and incidence of multiple drug resistance (MDR) pathogens. RESULTS: Pre-pandemic and pandemic incidence of VAP was 23.5 and 17.2 cases per 1000 device-days, respectively; an absolute decrease of 27%. The main reason for the decrease in the rate of VAP during the pandemic was a significant decrease in the rate of VAP caused by Acinetobacter baumannii; from 39 to 17% in total VAP episodes. The rate of VAP associated with other microorganisms remained relatively unchanged from 14.2 cases in pre-pandemic period to 14.3 cases per 1000 MV-days during the pandemic (P = 0.801). Pre-pandemic incidence of CLABSI was 7.3 cases and, in pandemic period, was 6.5 cases per 1000 device-days (IRR = 0.88, 95% CI 0.43-1.73, P = 0.703). Pre-pandemic incidence of CAUTI was 2 and in pandemic period, was 1.4 cases per 1000 device-days (IRR = 0.70, 95% CI 0.22-1.98, P = 0.469). CONCLUSION: The results of the present study showed a decrease in the incidence of VAP in critically ill non-COVID-19 patients during the pandemic compared to before the pandemic, especially regarding Acinetobacter baumannii.

Incidence, microbiological and immunological characteristics of ventilator-associated pneumonia assessed by bronchoalveolar lavage and endotracheal aspirate in a prospective cohort of COVID-19 patients: CoV-AP study.

BACKGROUND: No univocal recommendation exists for microbiological diagnosis of ventilator-associated pneumonia (VAP). Sampling of either proximal or distal respiratory tract likely impacts on the broad range of VAP incidence between cohorts. Immune biomarkers to rule-in/rule-out VAP diagnosis, although promising, have not yet been validated. COVID-19-induced ARDS made VAP recognition even more challenging, often leading to overdiagnosis and overtreatment. We evaluated the impact of different respiratory samples and laboratory techniques on VAP incidence and microbiological findings in COVID-19 patients. METHODS: Prospective single-centre cohort study conducted among COVID-19 mechanically ventilated patients in Policlinico Hospital (Milan, Italy) from January 2021 to May 2022. Microbiological confirmation of suspected VAP (sVAP) was based on concomitant endotracheal aspirates (ETA) and bronchoalveolar lavage (BAL). Conventional and fast microbiology (FILMARRAY® Pneumonia Panel plus, BALFAPPP) as well as immunological markers (immune cells and inflammatory cytokines) was analysed. RESULTS: Seventy-nine patients were included. Exposure to antibiotics and steroid therapy before ICU admission occurred in 51/79 (64.6%) and 60/79 (65.9%) patients, respectively. Median duration of MV at VAP suspicion was 6 (5-9) days. Incidence rate of microbiologically confirmed VAP was 33.1 (95% CI 22.1-44.0) and 20.1 (95% CI 12.5-27.7) according to ETA and BAL, respectively. Concordance between ETA and BAL was observed in 35/49 (71.4%) cases, concordance between BALFAPPP and BAL in 39/49 (79.6%) cases. With BAL as reference standard, ETA showed 88.9% (95% CI 70.8-97.7) sensitivity and 50.0% (95% CI 28.2-71.8) specificity (Cohen's Kappa 0.40, 95% CI 0.16-0.65). BALFAPPP showed 95.0% (95% CI 75.1-99.9) sensitivity and 69% (95% CI 49.2-84.7) specificity (Cohen's Kappa 0.60, 95% CI 0.39-0.81). BAL IL-1ß differed significantly between VAP (135 (IQR 11-450) pg/ml) and no-VAP (10 (IQR 2.9-105) pg/ml) patients (P = 0.03). CONCLUSIONS: In COVID-19 ICU patients, differences in microbial sampling at VAP suspicion could lead to high variability in VAP incidence and microbiological findings. Concordance between ETA and BAL was mainly limited by over 20% of ETA positive and BAL negative samples, while BALFAPPP showed high sensitivity but limited specificity when evaluating in-panel targets only. These factors should be considered when comparing results of cohorts with different sampling. BAL IL-1ß showed potential in discriminating microbiologically confirmed VAP. CLINICAL TRIAL REGISTRATION: NCT04766983, registered on February 23, 2021.

Modifications of lung microbiota structure in traumatic brain injury ventilated patients according to time and enteral feeding formulas: a prospective randomized study.

BACKGROUND: Specialized diets enriched with immune nutrients could be an important supplement in patients (pts) with acute traumatic brain injury (TBI). Omega-3 and arginine may interact with immune response and microbiota. No data are available about the role of the specialized diets in modulating the lung microbiota, and little is known about the influence of lung microbiota structure in development of ventilator-associated pneumonia (VAP) in TBI pts. The aims of this study are to evaluate the impact of specific nutrients on the lung microbiota and the variation of lung microbiota in TBI pts developing VAP. METHODS: A cohort of 31 TBI pts requiring mechanical ventilation in ICU was randomized for treatment with specialized (16pts) or standard nutrition (15pts). Alpha and beta diversity of lung microbiota were analyzed from bronco Alveolar Lavage (BAL) samples collected at admission and 7 days post-ICU admission in both groups. A further analysis was carried out on the same samples retrospectively grouped in VAP or no VAP pts. RESULTS: None developed VAP in the first week. Thereafter, ten out of thirty-one pts developed VAP. The BAL microbiota on VAP group showed significant differences in beta diversity and Staphylococcus and Acinetobacter Genera were high. The specialized nutrition had influence on beta diversity that reached statistical significance only in Bray-Curtis distance. CONCLUSION: Our data suggest that TBI patients who developed VAP during ICU stay have different structures of BAL microbiota either at admission and at 7 days post-ICU admission, while no correlation has been observed between different enteral formulas and microbiota composition in terms of richness and evenness. These findings suggest that targeting the lung microbiota may be a promising approach for preventing infections in critically ill patients.

Short-term exposure to ambient fine particulate pollution aggravates ventilator-associated pneumonia in pediatric intensive care patients undergoing cardiovascular surgeries.

BACKGROUND: Ambient air pollutants can be hazardous to human health, especially for vulnerable children. The impact of ambient air pollutant exposure before and during intensive care unit (ICU) stays on the development of ventilator-associated pneumonia (VAP) in critically ill children has not been established. We aimed to determine the correlations between short-term exposures to ambient fine particulate matter (PM2.5) and VAP in pediatric cardiac surgery patients in the ICU, and explore the effect of delayed exposure. METHODS: The medical record of 1755 child patients requiring artificial ventilation in the ICU between December 2013 to December 2020, were analyzed. The daily average concentrations of particulate matters (PM2.5 and PM10), sulfur dioxide (SO2), and ozone (O3) were calculated from public data. Interactions between these pollutants and VAP were simulated with the distributed lag non-linear model. RESULTS: Three hundred forty-eight cases (19.829%) of VAP were identified in this study, while the average concentrations of PM2.5, PM10, O3 and SO2 were 58, 118, 98 and 26 µg/m3, respectively. Exposure to increased levels of PM2.5 two days prior (lag 2-day) to VAP diagnosis is significantly correlated with an enhanced risk for VAP development. Even a slight increase of 10 µg/m3 in PM2.5 can translate to a 5.4% increase in VAP incidence (95% CI: 1.4%-9.5%) while the VAP incidence increased to 11.1% (95%CI: 4.5-19.5%) when PM2.5 concentration is well below the National Ambient Air Quality standard (NAAQS) of 50 µg/m3. The association was more pronounced in those aged below 3-months, with low body mass index or suffered from pulmonary arterial hypertension. CONCLUSION: Short-term PM2.5 exposure is a significant risk for development of VAP in pediatric patients. This risk is present even with PM2.5 levels below the NAAQS. Ambient PM2.5 may represent a previously unrecognized risk factor for pneumonia and the current environmental pollution standards need to be reevaluated to consider susceptible populations. TRIAL REGISTRATION: The trial was registered with the National Clinical Trial Center: The correlation between ambient air pollution and the complications in ICU underwent cardiac surgery. TRIAL REGISTRATION NUMBER: ChiCTR2000030507. Date of registration: March 5, 2020. URL of trial registry record: http://www.chictr.org.cn/index.aspx .

Genetic Variation among Heterodera schachtii Populations Coincided with Differences in Invasion and Propagation in Roots of a Set of Cruciferous Plants.

Genes of host plants and parasitic nematodes govern the plant-nematode interaction. The biological receptors and parasitism effectors are variable among plant species and nematode populations, respectively. In the present study, hatch testing and bioassays on cabbage, oilseed radish, and mustard were conducted to compare the biological characteristics among six populations of the beet cyst nematode Heterodera schachtii. Genetic patterns of the vap1 gene for the studied populations were distinct as shown by denaturing the gradient gel electrophoresis of PCR-amplified gene fragments. Concurrently, significant differences in the hatching rates, number of penetrated J2 in roots, and eggs/cyst ratios among the six nematode populations for the three cruciferous species were observed. In conclusion, analyzing the population genetic structure of H. schachtii plays a pivotal role in illustrating the variability in the plant-nematode interaction among its populations and plant species, which in its role leads to developing nematode management depending on plant resistance.