Bacterial Infection Group Research Articles

Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios in bacterial infections: contributions to diagnostic strategies in a tertiary care hospital in Tunisia.

Bacterial infections continue to pose a global health challenge, driven by antibiotic resistance and septicemia. This study aimed to assess the diagnostic utility of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in bacterial infections versus non-infectious causes of inflammation. A prospective study included 164 adult patients who were divided into two groups: a group of patients with confirmed bacterial infections and a second group of patients with other diagnoses (inflammatory pathologies, neoplasms, venous thromboembolic diseases, etc.). NLR and PLR values were compared between the bacterial infection group and the non-infectious causes group and the diagnostic performances of NLR and PLR for detecting bacterial infections were evaluated in comparison with other infection markers. NLR and PLR were significantly higher in bacterial infections (p < 10 ^-6), and NLR was correlated positively with inflammation markers. NLR and PLR demonstrated significant potential in diagnosing bacterial infections, with an AUC of 0.72 and 0.60, respectively, using the following cutoff values: 4.3 for NLR and 183 for PLR. These findings underscore the importance of NLR and PLR as adjunctive tools for bacterial infection diagnosis.

Cerebrospinal Fluid Neutrophil Gelatinase-Associated Lipocalin as a Novel Biomarker for Postneurosurgical Bacterial Meningitis: A Prospective Observational Cohort Study

BACKGROUND AND OBJECTIVES: Postneurosurgical bacterial meningitis (PNBM) was a significant clinical challenge, as early identification remains difficult. This study aimed to explore the potential of neutrophil gelatinase-associated lipocalin (NGAL) as a novel biomarker for the early diagnosis of PNBM in patients who have undergone neurosurgery. METHODS: A total of 436 postneurosurgical adult patients were enrolled in this study. Clinical information, cerebrospinal fluid (CSF), and blood samples were collected. After the screening, the remaining 267 patients were divided into the PNBM and non-PNBM groups, and measured CSF and serum NGAL levels to determine the diagnostic utility of PNBM. Subsequently, patients with PNBM were categorized into gram-positive and gram-negative bacterial infection groups to assess the effectiveness of CSF NGAL in differentiating between these types of infections. We analyzed the changes in CSF NGAL expression before and after anti-infection treatment in PNBM. Finally, an additional 60 patients were included as an independent validation cohort to further validate the diagnostic performance of CSF NGAL. RESULTS: Compared with the non-PNBM group, CSF NGAL was significantly higher in the PNBM group (305.1 [151.6-596.5] vs 58.5 [30.7-105.8] ng/mL; P &lt; .0001). The area under the curve of CSF NGAL for diagnosing PNBM was 0.928 (95% CI: 0.897-0.960), at a threshold of 119.7 ng/mL. However, there was no significant difference in serum NGAL between the 2 groups (142.5 [105.0-248.6] vs 161.9 [126.6-246.6] ng/mL, P = .201). Furthermore, CSF NGAL levels were significantly higher in patients with gram-negative bacterial infections than those with gram-positive bacteria (P = .023). In addition, CSF NGAL levels decrease after treatment compared with the initial stage of infection (P &lt; .0001). Finally, in this validation cohort, the threshold of 119.7 ng/mL CSF NGAL shows good diagnostic performance with a sensitivity and specificity of 90% and 80%, respectively. CONCLUSION: CSF NGAL holds promise as a potential biomarker for the diagnosis, early drug selection, and efficacy monitoring of PNBM.

Utility of the NLR and the ratio of NLR after and before adverse events for identifying irAEs and bacterial infections in patients with cancer during PD-(L)1 inhibitors treatment.

e14620 Background: Identifying immune-related adverse events (irAEs) or bacterial infections in cancer patients undergoing treatment with PD-(L)1 inhibitors can be challenging. This study aimed to assess the effectiveness of the neutrophil-to-lymphocyte ratio (NLR) in distinguishing between irAEs and bacterial infections in cancer patients receiving PD-(L)1 inhibitors. Methods: We conducted a retrospective analysis of cancer patients who received at least one dose of PD-(L)1 inhibitors at Affiliated Cancer Hospital of Zhengzhou University from 2018 to 2023. We compared the changes in peripheral blood cell counts before and after the occurrence of adverse events, as well as the ratio of the NLR at the time of adverse events (post-NLR) to the NLR before adverse events (pre-NLR). Bacterial infections were diagnosed based on clear etiology and/or controlled adverse events through the use of antibiotics without systemic glucocorticoid administration during treatment. irAEs were diagnosed based on clinicolaboratory criteria, or the improvement of immune system disorders after withdrawal of PD-(L)1 inhibitors or systemic glucocorticoid administration, excluding bacterial infection. Data were collected from microbiology, radiography, serology, and physician notes. Results: Among the 4173 patients who were administered PD-(L)1 inhibitors, 217 individuals experienced a total of 249 irAEs, while 256 patients were diagnosed with 257 bacterial infections. When comparing pre-infection levels with those after bacterial infection, it was observed that the NLR increased significantly. Similarly, in the group experiencing irAEs, the NLR also showed a significant increase after the occurrence of the irAEs. Notably, the NLR was significantly higher in patients with bacterial infections compared to those with irAEs [11.08 (6.63, 19.29) vs 2.78 (1.92, 4.31), P &lt; 0.001]. Furthermore, the post-NLR/pre-NLR ratio was higher in the bacterial infection group than in the irAEs group [2.86 (1.56, 6.20) vs 1.16 (0.82, 1.76), P &lt; 0.001]. Appraising the potential of NLR and the post-NLR/pre-NLR ratio in identifying irAEs and bacterial infections in cancer patients, the receiver operating characteristic (ROC) curve analysis was performed. The area under the curve (AUC) was 0.91 for NLR and 0.81 for the post-NLR/pre-NLR ratio, respectively. Using a cut-off value of 4.56 for NLR and 1.96 for the post-NLR/pre-NLR ratio yielded the highest sensitivity and specificity. Conclusions: The NLR along with the post-NLR/pre-NLR ratio could serve as valuable diagnostic indicators for irAEs and bacterial infections in cancer patients undergoing treatment with PD-(L)1 inhibitors.

Leukocyte activation patterns in hospitalized children: comparing SARS-CoV-2, bacterial infections, and inflammatory pathologies.

In adults, monocytes and neutrophils play important roles in the hyperinflammatory responses characteristic of severe forms of SARS-CoV-2 infection. We assessed leukocyte activation in 55 children attending the emergency department for acute fever between March 2020 and September 2021. The following markers were analyzed by flow cytometry: CD169 and HLA-DR on monocytes, CD64 and CD16 on neutrophils, and CD38 on lymphocytes TCD8. Fifteen of the children had SARS-CoV-2 infection, 15 had bacterial infections, and 15 had inflammatory diseases. We observed overexpression of CD169 on monocytes and CD38 on T lymphocytes in all patients with a diagnosis of SARS-CoV-2, while overexpression of CD64 on neutrophils was observed with bacterial infections and inflammatory diseases. There was a decrease in the expression of HLA-DR on monocytes in the bacterial infection and inflammatory pathology groups. Leukocyte analysis identifies distinct activation patterns in children during SARS-CoV-2 infections, bacterial infections, and inflammatory diseases.

Infection with the multidrug-resistant Klebsiella pneumoniae New Delhi metallo-B-lactamase strain in patients with COVID-19: Nec Hercules contra plures?

During the coronavirus disease 2019 (COVID-19) pandemic, in patients treated for SARS-CoV-2 infection, infections with the Klebsiella pneumoniae bacteria producing New Delhi metallo-B-lactamase (NDM) carbapenemase in the USA, Brazil, Mexico, and Italy were observed, especially in intensive care units (ICUs). This study aimed to assess the impact of Klebsiella pneumoniae NDM infection and other bacterial infections on mortality in patients treated in ICUs due to COVID-19. The 160 patients who qualified for the study were hospitalized in ICUs due to COVID-19. Three groups were distinguished: patients with COVID-19 infection only (N = 72), patients with COVID-19 infection and infection caused by Klebsiella pneumoniae NDM (N = 30), and patients with COVID-19 infection and infection of bacterial etiology other than Klebsiella pneumoniae NDM (N = 58). Mortality in the groups and chosen demographic data; biochemical parameters analyzed on days 1, 3, 5, and 7; comorbidities; and ICU scores were analyzed. Bacterial infection, including with Klebsiella pneumoniae NDM type, did not elevate mortality rates. In the group of patients who survived the acute phase of COVID-19 the prolonged survival time was demonstrated: the median overall survival time was 13 days in the NDM bacterial infection group, 14 days in the other bacterial infection group, and 7 days in the COVID-19 only group. Comparing the COVID-19 with NDM infection and COVID-19 only groups, the adjusted model estimated a statistically significant hazard ratio of 0.28 (p = 0.002). Multivariate analysis revealed that age, APACHE II score, and CRP were predictors of mortality in all the patient groups. In patients treated for SARS-CoV-2 infection acquiring a bacterial infection due to prolonged hospitalization associated with the treatment of COVID-19 did not elevate mortality rates. The data suggests that in severe COVID-19 patients who survived beyond the first week of hospitalization, bacterial infections, particularly Klebsiella pneumoniae NDM, do not significantly impact mortality. Multivariate analysis revealed that age, APACHE II score, and CRP were predictors of mortality in all the patient groups.

Procalcitonin in advanced urological cancer—bacterial versus non-bacterial infections: prospective cohort study

ObjectivesPatients with advanced cancer may develop bacterial infections (BI) as their general condition worsens, but general blood tests often find it difficult to distinguish them from non-bacterial infections (NBI). The...

Plasma proteome analysis and validation of patients with community-acquired pneumonia: A cohort study.

This study aimed to investigate the diagnostic potential of plasma biomarkers of community-acquired pneumonia (CAP) and their severity grading. Plasma proteomes from cohort I (n=32) with CAP were analyzed by data-independent acquisition mass spectrometry (MS). MetaboAnalyst 5.0 was used to statistically evaluate significant differences in proteins from different samples, and demographic and clinical data were recorded for all enrolled patients. Cohort II (n=80) was used to validate candidate biomarkers. Plasma protein levels were determined using quantitative enzyme-linked immunosorbent assay (ELISA). Correlations were assessed using Pearson's correlation coefficient. A receiver operating characteristic curve was used to verify the association between the variables, CAP diagnosis, and prognosis. 121 differentially expressed proteins (DEPs) were obtained between CAP and controls. These DEPs were mainly aggregated in pathways of phagosome(hsa04145) and complement and coagulation cascades (hsa04610). No significant differential proteins were detected in bacterial, viral, and mixed infection groups. The plasma levels of fetuin-A, alpha-1-antichymotrypsin (AACT), α1-acid glycoprotein (A1AG), and S100A8/S100A9 heterodimers detected by ELISA were consistent with those of MS. AACT, A1AG, S100A8/S100A9 heterodimer, and fetuin-A can potentially be used as diagnostic predictors, and fetuin-A and AACT are potential predictors of SCAP. Plasma protein profiling can successfully identify potential biomarkers for CAP diagnosis and disease severity assessment. These biomarkers should be further studied for their clinical application.

An exploration of the value of NLR, PLR, LMR, and WBC × CRP for the diagnosis and treatment of influenza B in adults.

The aim of the study was to study the diagnostic and therapeutic utility of NLR (neutrophil-to-lymphocyte ratio), LWR (lymphocyte-to-monocyte ratio), PLR (platelet-to-lymphocyte ratio), and WBC × CRP (WBC: white cell count, CRP: C-reactive protein) in patients with influenza B. This retrospective study included 122 adult patients with influenza B, 176 adult patients with bacterial infection, and 119 adult healthy physical examinees for routine blood examination and CRP testing, calculation of NLR, LMR, PLR, and WBC × CRP for relevant statistical analysis, monitoring of NLR, LMR, PLR and WBC × CRP in patients with influenza B during relevant treatment. All indicators, except for WBC and NLR, had no statistical differences between the influenza B group, the normal control group, and the influenza B group and bacterial infection group, respectively, and showed no statistical significance for the differences between the groups. The diagnostic effect of LMR and WBC × CRP was deemed good or excellent in patients with influenza B, healthy people, and patients with a bacterial infection. Conversely, NLR and PLR could only distinguish patients with influenza B from healthy people but remained unable to identify different pathogens. Moreover, many false negatives were noted for WBC and CRP during the diagnosis of influenza B. Also, NLR, LMR, PLR, and WBC × CRP exerted a good effect in evaluating curative effect and conditions for influenza B. LMR and WBC × CRP have a relatively high value in the early diagnosis of adults suffering from influenza B. Also, NLR and PLR excelled at differentiating adult patients with influenza B from healthy people. Therefore, NLR, PLR, LMR, and WBC × CRP can all be used for disease course monitoring and efficacy evaluation.

Effects of myeloperoxidase on inflammatory responses with hypoxia in Citrobacter rodentium-infectious mice.

Myeloperoxidase (MPO)has been identified as a mediator in various inflammatory diseases. Bacterial infection of the intestine and hypoxia can both lead to inflammatory responses, but the role of MPO in these phenomena remains unclear. By building the MPO-/- mice, we evaluated relevant inflammatory factors and tissue damage in mice with intestinal Citrobacter rodentium infection and hypoxia. The body weight and excreted microorganisms were monitored. Intestinal tissues were collected 7 days after bacterial infection under hypoxia to undergo haematoxylin-eosin staining and assess the degree of pathological damage. ELISA assays were performed to quantify the serum levels of TNF-α, IFN-γ, IL-6, and IL-1β inflammatory cytokines. PCR, WB, and IF assays were conducted to determine the expression of chemokines MCP1, MIP2, and KC in the colon and spleen. The C. rodentium infection and hypoxia caused weight loss, intestinal colitis, and splenic inflammatory cells active proliferation in wild-type mice. MPO deficiency alleviated this phenomenon. MPO-/- mice also displayed a significant decline in bacteria clearing ability. The level of TNF-α in the serum and spleen was both lower in MPO-/- hypoxia C. rodentium-infected mice than that in wild-type mice. The chemokines expression levels of MIP2, KC,and MCP1 in the spleen and colon of each bacterial infected group were significantly increased (p < .05), while in hypoxia, the factors in the spleen and colon were decreased (p < .05). MPO deficiency was found to lower the levels of these chemokines compared with wild-type mice. MPO plays an important role of the inflammatory responses in infectious enteritis and hypoxia in mice, and the loss of MPO may greatly reduce the body's inflammatory responses to fight diseases.

Diagnosis of bacterial and viral infection by HNL, SAA, PCT and CRP combined test

The value of combined detection of neutrophil apolipoprotein (HNL), serum amyloid A (SAA), procalcitonin (PCT) and C-reactive protein (CRP) in the differential diagnosis of bacterial and viral infectious diseases. A retrospective study was conducted to collect the clinical data of infected patients and healthy people in the clinical department of Shaanxi Provincial People's Hospital from September to December in 2022. 100 patients with confirmed infection were divided into bacterial infection group (n=50) and virus infection group (n=50), and 50 healthy people were selected as control group (n=50). Fasting venous blood was collected at the initial stage of admission or on the day of physical examination. HNL was detected by double antibody sandwich method, SAA and CRP were detected by nephelometry, and PCT was detected by chemiluminescence method. The efficacy of infection markers in the differential diagnosis of bacterial infection and viral infection in infected patients was evaluated. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of HNL, SAA, PCT and CRP in bacterial and viral infectious diseases; Logistic regression was used to analyze the influence of each index on the diagnostic efficiency. The results showed that the levels of HNL (126.60±33.32) ng/ml, PCT (28.02±11.37) ng/ml and CRP (36.13±14.37) mg/L in bacterial infection group were significantly higher than those of HNL (47.72±15.94) ng/ml, PCT (1.27±0.40) ng/ml, CRP (18.77±10.66) mg/L in virus group and HNL (38.21±12.53) ng/ml, PCT (0.38±0.12) ng/ml and CRP (4.13±1.07) mg/L in control group. The level of HNL increased most significantly (F=89.228, P<0.05). The area under ROC curve (AUC) from large to small was HNL+SAA+PCT+CRP (0.976), HNL (0.907), PCT (0.885), CRP (0.856), SAA (0.790), SAA/CRP (0.733). The level of SAA/CRP in virus infection group (94.05±3.75) was significantly higher than that in bacteria group (17.70±3.69) and control group (3.89±1.50) (F=84.005, P<0.05). The area under ROC curve (AUC) from large to small was HNL+SAA+PCT+CRP (0.986), SAA/CRP (0.956), SAA (0.878), HNL (0.768), CRP (0.742), PCT (0.730). In conclusion, HNL has the best auxiliary diagnostic efficacy in bacterial infection, followed by PCT; SAA/CRP has the best auxiliary diagnostic efficacy in viral infection, followed by SAA; the combined detection of serum HNL, SAA, PCT and CRP may be helpful for the differential diagnosis of bacterial and viral infections.

Prognostic differences in sepsis caused by gram-negative bacteria and gram-positive bacteria: a systematic review and meta-analysis

BackgroundBacteria are the main pathogens that cause sepsis. The pathogenic mechanisms of sepsis caused by gram-negative and gram-positive bacteria are completely different, and their prognostic differences in sepsis remain unclear.MethodsThe PubMed, Web of Science, Cochrane Library, and Embase databases were searched for Chinese and English studies (January 2003 to September 2023). Observational studies involving gram-negative (G (−))/gram-positive (G (+)) bacterial infection and the prognosis of sepsis were included. The stability of the results was evaluated by sensitivity analysis. Funnel plots and Egger tests were used to check whether there was publication bias. A meta-regression analysis was conducted on the results with high heterogeneity to identify the source of heterogeneity. A total of 6949 articles were retrieved from the database, and 45 studies involving 5586 subjects were included after screening according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Twenty-seven high-quality studies and 18 moderate-quality studies were identified according to the Newcastle‒Ottawa Scale score. There was no significant difference in the survival rate of sepsis caused by G (−) bacteria and G (+) bacteria (OR 0.95, 95% CI 0.70–1.28). Subgroup analysis according to survival follow-up time showed no significant difference. The serum concentrations of C-reactive protein (CRP) (SMD = 0.39, 95% CI 0.02–0.76), procalcitonin (SMD = 1.95, 95% CI 1.32–2.59) and tumor necrosis factor-alpha (TNF-α) (MD = 0.31, 95% CI 0.25–0.38) in the G (−) bacterial infection group were significantly higher than those in the G (+) bacterial infection group, but there was no significant difference in IL-6 (SMD = 1.33, 95% CI − 0.18–2.84) and WBC count (MD = − 0.15, 95% CI − 0.96–00.66). There were no significant differences between G (−) and G (+) bacteria in D dimer level, activated partial thromboplastin time, thrombin time, international normalized ratio, platelet count, length of stay or length of ICU stay. Sensitivity analysis of the above results indicated that the results were stable.ConclusionThe incidence of severe sepsis and the concentrations of inflammatory factors (CRP, PCT, TNF-α) in sepsis caused by G (−) bacteria were higher than those caused by G (+) bacteria. The two groups had no significant difference in survival rate, coagulation function, or hospital stay. The study was registered with PROSPERO (registration number: CRD42023465051).

Analysis of HPV prevalence among individuals with reproductive tract infections in a Chinese population.

The previous research has found that human papillomavirus (HPV) infection is the main cause of cervical cancer, but it is still unclear whether HPV infection, as well as the HPV genotypes, are related to reproductive tract infections in the Chinese population. Patients who underwent HPV screening at Shandong Maternal and Child Health Hospital were selected, and the HPV infection status was analyzed among patients with cervical lesions, bacterial vaginosis, cervical inflammation, fungal vaginitis, and pelvic infections. SPSS 22 statistical analysis was used to analyze the differences in HPV infection types and rates between the control group and the experimental group. The HPV infection rate of bacterial vaginosis (χ2 = 13.4; P < .001) and fungal vaginitis (χ2 = 3.3; P < .045) are both significantly different from the control group. The single HPV infections reveals significant differences from control group in bacterial vaginosis (χ2 = 7.3; P = .004), fungal vaginitis (χ2 = 4.5; P = .023), and cervical lesions (χ2 = 58.8; P < .001). In the bacterial infection group, HPV51 (1.9%; χ2 = 6.0; P = .008) and HPV58 (4.7%; χ2 = 3.3; P = .044) showed significant differences in infection compared to the control group. In the fungal infection group, HPV39 (2.7%; χ2 = 4.7; P = .032) showed a significant difference in infection compared to the control group. Cervical lesions, bacterial vaginosis, fungal vaginitis, and cervical lesions among Chinese population exhibit age-specified distribution. HPV infection rate in bacterial vaginitis, fungal vaginitis and cervical lesions was higher than that in normal group. HPV52 and HPV16 infection are different, and HPV39 is different between bacterial vaginitis and fungal vaginitis.

Diagnostic value of serum CRP, PCT and IL-6 in children with nephrotic syndrome complicated by infection: a single center retrospective study.

The purpose was to look into the diagnostic value of serum CRP, PCT and IL-6 in children with nephrotic syndrome co-infection. One hundred and forty-nine children with nephrotic syndrome who met the inclusion and exclusion criteria were included in this study. The children were divided into three groups: bacterial infection group, non-bacterial infection group, and non-infection group. The diagnostic value was analyzed and compared using the ROC curve. There was no statistically significant difference in the Leukocyte counts among three groups. The mean results of serum CRP, PCT and IL-6 were significantly higher in the bacterial infection group compared to those in the non-infection group (p < 0.05). AUC of CRP, PCT, IL-6 in bacterial infection were 0.791, 0.859, 0.783. The following combinations CRP + PCT + IL-6, IL-6 + PCT, CRP + PCT significantly increased the efficiency of bacterial infection diagnosis, the AUCs were 0.881, 0.884, and 0.884, respectively. AUC of PCT in non-bacterial infection was 0.663. The combinations of these three clinical indicators performed no better than PCT in ROC analysis. Normal CRP or IL-6 levels do not rule out the diagnosis of bacterial infection in children on long-term glucocorticoid therapy. The appropriate combination of two or three indicators can improve the diagnostic value. This study evaluated the diagnostic value of the serum concentrations of CRP, PCT and IL-6 and assessed whether the value of their combined application is better than when used alone for diagnosing primary nephrotic syndrome complicated by infection. The elevation in leukocyte count cannot be used to diagnose children with nephrotic syndromes on long-term glucocorticoid treatment who have bacterial infections. Normal CRP or IL-6 levels do not rule out the diagnosis of bacterial infection in children on long-term glucocorticoid therapy. The appropriate combination of two or three indicators can improve diagnostic value, sensitivity, and specificity.

Bacterial co-infection raises in-hospital mortality of COVID-19 patients: a retrospective study.

We aim to explore whether the bacterial co-infection with COVID-19 will raise the in-hospital mortality. COVID-19 patients' information were collected for analysis in our retrospective study. Neutrophil count and procalcitonin (PCT) were used to estimate whether there was a suspected bacterial co-infection. The main baselines between the suspected bacterial infection (SBI) and no evidence of bacterial infection (NBI) groups were no significant differences. In SBI group, patients required more therapies than NBI group. There was significantly higher in-hospital mortality (26% vs.9%, P < 0.001) between SBI and NBI groups in overall population. And in each subgroup based on pneumonia inflammation index (PII), it also showed higher in-hospital mortality of COVID-19 patients with bacterial co-infection. With logistic regression models, it showed that bacterial co-infection was associated with significantly higher in-hospital mortality in overall population (OR 1.694, 95% CI 1.179-2.434, p = 0.004) and mild subgroup (OR 2.374, 95% CI 1.249-4.514, p = 0.008). The rate of bacterial co-infection in overall population was 51%. At the same time, it showed a significantly higher rate of bacterial co-infection in critical subgroup than severe subgroup (63% vs. 49%, p = 0.003), and than that in moderate subgroup (63% vs. 48%, p = 0.002) based on clinical classification. It showed a significantly higher rates of bacterial co-infection in severe subgroup than moderate subgroup (66% vs. 49%, p = 0.001) based on PII. The result showed that the risk factor associated with significantly higher in-hospital mortality was PII (OR 1.018, 95%CI 1.012 to 1.024, P < 0.001) with logistic regression models. Bacterial co-infection estimated by Neutrophil count and procalcitonin significantly raises in-hospital mortality of COVID-19 patients in overall population in our study. Its impact is more significant in mild and moderate PII subgroups. PII based on CT imaging combined with neutrophil count and PCT is beneficial for accurate differentiation of bacterial co-infection of COVID-19.

Clinical characteristics analysis and construction of a predictive diagnostic model of community-acquired pneumonia in adults requiring hospitalization in Fujian provincial hospital

Abstract BACKGROUND: This study aimed to compare the clinical characteristics of infections caused by different pathogens and then establish a viral/bacterial infection prediction model to guide early clinical identification of pathogens in inpatients with community-acquired pneumonia (CAP). METHODS: A total of 687 patients who were diagnosed with CAP in our hospital between March 2012 and December 2018 were studied. Basic data, clinical symptoms, laboratory examinations, and imaging examinations of patients were collected, and a virus/bacteria prediction equation was established. In the prediction model, the relevant variables were screened according to a univariate logistic regression analysis, and then, a multivariate logistic regression analysis was performed to establish the prediction equation. RESULTS: The proportions of patients with muscle soreness and headaches were significantly higher in the viral infection group than in the bacterial infection group. Procalcitonin (PCT) concentrations, the erythrocyte sedimentation rate (ESR), and the neutrophil alkaline phosphatase (NAP) score were significantly higher in the bacterial infection group than in the viral infection group. Creatine kinase concentrations were significantly higher in the viral infection group than in the bacterial infection group (P &lt; 0.05). A higher proportion of patients had lung degeneration in the atypical pathogen infection group than in other groups (P = 0.005). Patchy shadows were more common in the viral infection group than in the other groups. A binary logistic regression equation was obtained that could predict the probability of viral infection (sensitivity: 57.5%, specificity: 67.7%, and area under the receiver operating characteristics curve: 0.651). CONCLUSIONS: Adult patients with CAP and viral infection are more likely to have headaches and muscle soreness than those with bacterial infection. An elevated PCT concentration, NAP score, and ESR indicate a high possibility of bacterial infection. We successfully established a viral and bacterial infection prediction model.

The Applicability of a 2-Transcript Signature to Identify Bacterial Infections in Children with Febrile Neutropenia.

Febrile neutropenia is a common complication during chemotherapy in paediatric cancer care. In this setting, clinical features and current diagnostic tests do not reliably distinguish between bacterial and viral infections. Children with cancer (n = 63) presenting with fever and neutropenia were recruited for extensive microbiological and blood RNA sampling. RNA sequencing was successful in 43 cases of febrile neutropenia. These were classified as having probable bacterial infection (n = 17), probable viral infection (n = 13) and fever of unknown origin (n = 13) based on microbiological defined infections and CRP cut-off levels. RNA expression data with focus on the 2-transcript signature (FAM89A and IFI44L), earlier shown to identify bacterial infections with high specificity and sensitivity, was implemented as a disease risk score. The median disease risk score was higher in the probable bacterial infection group, -0.695 (max 2.795; min -5.478) compared to the probable viral infection group -3.327 (max 0.218; min -7.861), which in ROC analysis corresponded to a sensitivity of 0.88 and specificity of 0.54 with an AUC of 0.80. To further characterise the immune signature, analysis of significantly expressed genes and pathways was performed and upregulation of genes associated to antibacterial responses was present in the group classified as probable bacterial infection. Our results suggest that the 2-transcript signature may have a potential use as a diagnostic tool to identify bacterial infections in immunosuppressed children with febrile neutropenia.

CD64 as a diagnostic marker for bacterial infection in acute bronchiolitis

Objectives: The aim of this study was to determine the association between neutrophils and monocytes CD 64 molecules and cases of bronchiolitis with an associated bacterial infection. Methods: Blood samples were obtained from patients younger than 2 years old diagnosed with bronchiolitis. Complete blood count (CBC), blood culture, procalcitonin, and CD64 surface expression in neutrophils and monocytes were examined using flow cytometry. We also assessed CBC, procalcitonin, and CD64 levels in neutrophils and monocytes in 31 healthy control subjects. Results: Sixty-two patients with lower respiratory tract infections were included in the first group. The patients were divided into 34 with non-bacterial infections and 28 with possible bacterial infections. We found a significant increase in the number of positive cells in the Mean Fluorescence Intensity (MFI) of both nCD64 and mCD64 in the Possible Bacterial Infection (PBI) group. Procalcitonin levels correlated with nCD64 and nCD64%, but not with mCD64. The AUC of nCD64 was 0.873 (at a cut-off point of 4489.4; the MFI had a specificity of 73% and a sensitivity of 94%). Conclusion: Neutrophil CD64 may be a marker for bacterial infection in children with bronchiolitis.

Infection in systemic lupus erythematosus-associated diffuse alveolar hemorrhage: a potential key to improve outcomes.

This study aimed to investigate the clinical characteristics, outcomes, and associated factors of patients with systemic lupus erythematosus-associated diffusive alveolar hemorrhage (SLE-DAH) stratified by infection status in a national representative cohort. This single-center retrospective study included 124 consecutive patients with SLE-DAH in a tertiary care center between 2006 and 2021. The diagnosis of DAH was made based on a comprehensive evaluation of clinical manifestations, laboratory and radiologic findings, and bronchoalveolar lavage. Demographics, clinical features, and survival curves were compared between patients with bacterial, non-bacterial, and non-infection groups. Univariate and multivariate logistic regression analyses were performed to determine the factors independently associated with bacterial infection in SLE-DAH. Fifty-eight patients with SLE-DAH developed bacterial infection after DAH occurrence, thirty-two patients developed fungal and/or viral infection, and thirty-four patients were categorized as non-infection. The bacterial infection group have a worse prognosis (OR 3.059, 95%CI 1.469-6.369, p = 0.002) compared with the other two groups, with a mortality rate of 60.3% within 180days after DAH occurrence. Factors independently associated with bacterial infections in SLE-DAH included hematuria (OR 4.523, 95%CI 1.068-19.155, p = 0.040), hemoglobin drop in the first 24h after DAH occurred (OR 1.056, 95%CI 1.001-1.115, p = 0.049), and anti-Smith antibody (OR 0.167, 95%CI 0.052-0.535, p = 0.003). Glucocorticoid pulse therapy and cyclophosphamide were administered in more than 50% of patients regardless of their infectious status. According to clinical experience at our hospital and in previous studies, we recommended a comprehensive management algorithm for SLE-DAH based on infection stratification. Infection, especially bacterial infection, is a severe complication and prognostic factor of SLE-DAH. Comprehensive management strategies, including diagnosis, evaluation, treatment, and monitoring, based on infection stratification may fundamentally improve outcomes of patients with SLE-DAH. Key Points • Bacterial infection is an important, but neglected, prognosis factor of systemic lupus erythematosus (SLE)-associated diffusive alveolar hemorrhage (DAH). • Hematuria, hemoglobin drop, and anti-Smith antibody can independently predict bacterial infections in SLE-DAH. • We put forward a comprehensive management algorithm based on infection stratification for SLE-DAH.

Transcriptome sequencing of the spleen of the Yangtze sturgeon (Acipenser dabryanus) under Edwardsiella tarda and poly(I:C) treatments

Acipenser dabryanus is an ancient living fossil and a flagship species of the Yangtze River. However, A. dabryanus was listed as a critically endangered species due to the dramatic decrease in its population, and disease outbreaks occurring during captive breeding have hindered the protection of this species. Here, we investigated the effect of the pathogenic bacterium Edwardsiella tarda and poly(I:C) on A. dabryanus at the histopathological and transcriptomic levels. After 48 h of infection with E. tarda, A. dabryanus exhibited marked pathological changes in the intestine and liver. We then conducted full-length transcriptome sequencing of the spleen by SMRT sequencing technology. Using the full-length transcriptome data as a reference, transcriptomic results obtained through Illumina sequencing technology revealed that a total of 894 and 963 unigenes were differentially expressed between the PBS and bacterial infection groups and between the PBS and poly(I:C) challenge groups, respectively. E3 ubiquitin ligases family members, T-cell receptor and clusters of differentiation were significantly upregulated by bacteria or poly(I:C) treatment, while the complement was significantly downregulated, suggesting that they might participate in multiple immune pathways in the response to pathogen invasion. Pathogen infection also induced changes in some key rate-limiting enzymes involved in energy metabolism. Our study can provide important information on the molecular mechanisms underlying the immune response of fish to pathogenic microbial infections and help explore the antibacterial and antiviral immunity of A. dabryanus.

Use of serum procalcitonin (PCT) level and PCT mRNA expression as a potential clinical biomarker in cats with bacterial and viral infections.

The aim of this study was to investigate the use of procalcitonin (PCT) as a biomarker in differentiating bacterial infections from viral infections in cats. In addition, the relationship between PCT and mortality rate was also examined. Forty-five cats were included in the study. The cats were categorised into two groups: bacterial (n = 20) and viral (n = 25) infection. Serum PCT level and PCT mRNA expression were analysed from blood samples collected before treatment. Serum PCT level and PCT mRNA expression of the cats with presumed bacterial infection were higher than those with viral infection (P = 0.001 and P = 0.001, respectively). The receiver operating characteristic (ROC) curve analysis revealed an area under the ROC curve value of 0.888 for serum PCT and 0.850 for PCT mRNA expression. There was no statistically significant difference among respiratory, urinary and gastrointestinal tract infections regarding serum PCT level and PCT mRNA expression in the presumed bacterial infection group (P = 0.741 and P = 0.141, respectively). In the presumed bacterial infection group, serum PCT level and PCT mRNA expression in the non-surviving cats were higher than those of the surviving cats (P = 0.021 and P = 0.026, respectively). Serum PCT level and PCT mRNA expression were considered efficient biomarkers in cats to distinguish a bacterial infection from a viral infection. Moreover, ROC curve analysis was highly accurate in the discriminative capacity of these two parameters. PCT level and PCT mRNA expression offer substantial assistance in an efficient therapeutic approach and in avoiding unnecessary antibiotic use in feline clinical practice, particularly in emergency patients and those with non-specific clinical signs, decreasing the mortality rate. However, it should be noted that these data are only research data. More detailed future studies are needed.