OBJECTIVES: Bloodstream infections in emergency patients have a high incidence, severe disease progression, and rapid deterioration. Early administration of appropriate antimicrobial agents is crucial for improving patient outcomes. This study aims to investigate the incidence, pathogen distribution, and antimicrobial resistance patterns of bloodstream infections in emergency patients, providing a reference for rational antibiotic use in clinical practice. METHODS: Medical records of patients diagnosed with bloodstream infections in the emergency department of a hospital in Hunan Province between January 2018 and October 2022 were retrospectively collected. Clinical characteristics of bloodstream infection patients were analyzed, and the distribution trends and antimicrobial susceptibility of clinical isolates were examined. RESULTS: During the study period, 2 215 blood culture samples were submitted from the emergency department, with a positivity rate of 13.27%. After excluding eight cases with missing data or suspected contamination, 286 patients with bloodstream infections were included, with community-acquired infections accounting for the majority (85.66%). The most common primary infection site was the urinary tract (24.48%), followed by respiratory tract infections (20.28%) and biliary and intra-abdominal infections (17.13%). The 30-day mortality rate of bloodstream infections was 16.08%. A total of 286 pathogens were isolated, including 181 (63.29%) Gram-negative bacteria, primarily Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa; 101 (35.31%) Gram-positive bacteria, mainly Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pneumoniae; and only 4 (1.40%) fungal isolates. Antimicrobial susceptibility testing showed that the key Enterobacteriaceae strains exhibited resistance rates of 2.4% to carbapenems, 16.3% to piperacillin sodium and tazobactam sodium, and 15.3% to ceftazidime, with no detected resistance to tigecycline or polymyxins. The main non-fermentative bacteria showed resistance rates of 29.6% to piperacillin sodium and tazobactam sodium, 13.3% to cefoperazone sodium and sulbactam sodium, and 27.1% to quinolones. Among Gram-negative bacteria, multidrug-resistant strains accounted for 40.9% (74/181), with carbapenem-resistant Escherichia coli and Klebsiella pneumoniae detected in 5.4% (5/92) and 13.6% (6/44) of cases, respectively. No carbapenem-resistant Pseudomonas aeruginosa was identified. Among Gram-positive bacteria, resistance rates to penicillin G, rifampicin, and cefoxitin were 74.7%, 4.2%, and 50%, respectively, with only 3 cases of resistant to glycopeptide antibiotics. CONCLUSIONS Bloodstream infections in emergency patients are predominantly community-acquired, with Gram-negative bacteria being the most common pathogens. The isolated pathogens exhibited relatively low resistance rates to commonly used clinical antibiotics.
Retrospective Studies ; Emergency Service, Hospital/statistics & numerical data* ; Drug Resistance, Bacterial ; Anti-Bacterial Agents/therapeutic use* ; Incidence ; Microbial Sensitivity Tests/statistics & numerical data* ; Bacteremia/microbiology* ; Community-Acquired Infections/microbiology* ; Gram-Negative Bacteria/isolation & purification* ; Blood Culture/statistics & numerical data* ; Humans ; Male ; Female ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Aged ; Aged, 80 and over ; China/epidemiology*

Bacteremia induced by periodontal infection is an important factor for periodontitis to threaten general health. P. gingivalis DNA/virulence factors have been found in the brain tissues from patients with Alzheimer's disease (AD). The blood-brain barrier (BBB) is essential for keeping toxic substances from entering brain tissues. However, the effect of P. gingivalis bacteremia on BBB permeability and its underlying mechanism remains unclear. In the present study, rats were injected by tail vein with P. gingivalis three times a week for eight weeks to induce bacteremia. An in vitro BBB model infected with P. gingivalis was also established. We found that the infiltration of Evans blue dye and Albumin protein deposition in the rat brain tissues were increased in the rat brain tissues with P. gingivalis bacteremia and P. gingivalis could pass through the in vitro BBB model. Caveolae were detected after P. gingivalis infection in BMECs both in vivo and in vitro. Caveolin-1 (Cav-1) expression was enhanced after P. gingivalis infection. Downregulation of Cav-1 rescued P. gingivalis-enhanced BMECs permeability. We further found P. gingivalis-gingipain could be colocalized with Cav-1 and the strong hydrogen bonding between Cav-1 and arg-specific-gingipain (RgpA) were detected. Moreover, P. gingivalis significantly inhibited the major facilitator superfamily domain containing 2a (Mfsd2a) expression. Mfsd2a overexpression reversed P. gingivalis-increased BMECs permeability and Cav-1 expression. These results revealed that Mfsd2a/Cav-1 mediated transcytosis is a key pathway governing BBB BMECs permeability induced by P. gingivalis, which may contribute to P. gingivalis/virulence factors entrance and the subsequent neurological impairments.
Animals ; Rats ; Bacteremia/metabolism* ; Blood-Brain Barrier/microbiology* ; Caveolin 1/metabolism* ; Gingipain Cysteine Endopeptidases/metabolism* ; Permeability ; Porphyromonas gingivalis/pathogenicity* ; Transcytosis ; Virulence Factors/metabolism*

Blood stream infection (BSI),a blood-borne disease caused by microorganisms such as bacteria,fungi,and viruses,can lead to bacteremia,sepsis,and infectious shock,posing a serious threat to human life and health.Identifying the pathogen is central to the precise treatment of BSI.Traditional blood culture is the gold standard for pathogen identification,while it has limitations in clinical practice due to the long time consumption,production of false negative results,etc.Nanopore sequencing,as a new generation of sequencing technology,can rapidly detect pathogens,drug resistance genes,and virulence genes for the optimization of clinical treatment.This paper reviews the current status of nanopore sequencing technology in the diagnosis of BSI.
Humans ; Nanopore Sequencing ; Sepsis/diagnosis* ; Bacteremia/microbiology* ; Bacteria ; Blood Culture/methods*

No abstract available.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Bacteremia/blood/*diagnosis/microbiology ; C-Reactive Protein/analysis ; Cholecystitis/blood/cerebrospinal fluid/microbiology ; Electrophoresis, Gel, Pulsed-Field ; Enterococcus faecium/drug effects/isolation & purification/metabolism ; Humans ; Male ; Microbial Sensitivity Tests ; Microscopy, Electron, Scanning ; Ochrobactrum/drug effects/isolation & purification/*metabolism ; RNA, Ribosomal, 16S/analysis/genetics/metabolism ; Sequence Analysis, DNA ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Megalocytic interstitial nephritis is a rare form of kidney disease caused by chronic inflammation. We report a case of megalocytic interstitial nephritis occurring in a 45-yrold woman who presented with oliguric acute kidney injury and acute pyelonephritis accompanied by Escherichia coli bacteremia. Her renal function was not recovered despite adequate duration of susceptible antibiotic treatment, accompanied by negative conversion of bacteremia and bacteriuria. Kidney biopsy revealed an infiltration of numerous histiocytes without Michaelis-Gutmann bodies. The patient's renal function was markedly improved after short-term treatment with high-dose steroid.
Acute Disease ; Acute Kidney Injury/complications/*drug therapy/pathology ; Anti-Bacterial Agents/therapeutic use ; Azithromycin/therapeutic use ; Bacteremia/*drug therapy/microbiology/pathology ; Cefotaxime/therapeutic use ; Creatinine/blood ; Escherichia coli ; Escherichia coli Infections/*drug therapy/microbiology/pathology ; Female ; Humans ; Kidney/pathology ; Methylprednisolone/therapeutic use ; Middle Aged ; Nephritis, Interstitial/*drug therapy/immunology/pathology ; Pyelonephritis/complications/*drug therapy/pathology ; Renal Dialysis ; Shock, Septic/drug therapy/microbiology

IN the presence of septic shock, every hour in delaying the administration of effective antibiotics is associated with a measurable increase in mortality. This is especially true for neutropenic patients with septic shock.1 As there is a higher incidence of involving multi-drug resistant pathogens for neutropenic patients, the decision on antibiotics regime remains a challenge for physicians.2 Immunosuppression and previous antibacterial use are factors that promote the spread of multi-drug resistant pathogens, and the possibility of co-existing multi-drug resistant pathogens should be suspected when treating patients with these risk factors who developed refractory shock. Here we present a case with neutropenic fever and refractory shock whose blood culture yielded multi-drug resistant Acinetobacter baumannii and carbapenem- resistant Klebsiella pneumoniae.
Acinetobacter Infections ; blood ; drug therapy ; microbiology ; Acinetobacter baumannii ; drug effects ; isolation & purification ; Adult ; Bacteremia ; blood ; drug therapy ; microbiology ; Carbapenems ; administration & dosage ; pharmacology ; therapeutic use ; Drug Resistance, Multiple, Bacterial ; Fatal Outcome ; Humans ; Klebsiella Infections ; blood ; drug therapy ; microbiology ; Klebsiella pneumoniae ; drug effects ; isolation & purification ; Male ; Shock, Septic ; blood ; drug therapy ; microbiology

INTRODUCTIONThe aim of this study was to externally validate the Cham score for the prediction of bacteraemia in emergency department (ED) patients with non-hospital acquired pneumonia.

MATERIALS AND METHODSThis is a secondary analysis of a dataset collected to identify independent predictors of bacteraemia in adult ED patients with non-hospital acquired pneumonia. The primary outcome of interest was the predictive performance (sensitivity, specificity, negative predictive value) of the score with respect to bacteraemia. Secondary outcomes included the performance of the score in patients not known to be intravenous (IV) drug users, the predictive performance of pneumonia severity index (PSI) class IV/V and PSI class IV/V or IV drug use as predictors and the clinical impact of score application on test ordering. Data analysis was by clinical performance and receiver operator characteristic curve analysis.

RESULTSA total of 200 patients were studied; 14 true positive blood cultures (7%, 95% CI, 4% to 11%). The Cham score had a sensitivity of 92.9% (95% CI, 64.2% to 99.6%), specificity of 26.3% (95% CI, 20.3% to 33.4%) and negative predictive value (NPV) of 98% (87.0% to 99.9%). Area under the receiver operating characteristic (ROC) curve was 0.71 (95% CI, 0.56 to 0.86). Using PSI class IV/V or known IV drug use as predictors had sensitivity of 92.9% (95% CI, 64.2% to 99.6%), specificity of 51.1% (95% CI, 43.7% to 58.4%) and NPV of 99% (95% CI, 93.5% to 99.9%).

CONCLUSIONIn retrospective external validation, the Cham score performed better than in derivation with acceptable sensitivity and NPV. Simplified criteria (PSI class IV/V or known IV drug use), as yet not validated, had similar sensitivity and NPV but would avoid blood cultures in a higher proportion of patients.

Aged ; Aged, 80 and over ; Bacteremia ; blood ; diagnosis ; Bacteriological Techniques ; utilization ; Emergency Service, Hospital ; Female ; Hematologic Tests ; utilization ; Humans ; Male ; Middle Aged ; Pneumonia, Bacterial ; blood ; microbiology ; Retrospective Studies

This study was purposed to evaluate the diagnostic value of procalcitonin (PCT), C-reactive protein, interleukin-6 (IL-6), serum amyloid A (SAA) for bacteremia in patients with hematologic malignancy combined with febrile neutropenia. The total of 297 patients with hematologic malignancy combined with febrile neutropenia were analyzed retrospectively from 1253 patients admitted to West China hospital of Sichuan University from March 2011 to October 2012. They were divided into sepsis group (n = 95) and non-sepsis group (n = 202) according to blood culture. The results showed that the levels of PCT, CRP, IL-6 and SAA in sepsis group were higher than those in non-sepsis group, and there was statistically significant difference between these two groups (P < 0.05). The PCT had an AUC value of 0.974 (P < 0.05), and obviously higher than that of CRP (AUC = 0.681, P < 0.05), IL-6 (AUC = 0.661, P < 0.05) and SAA (AUC = 0.605, P < 0.05). When PCT had cut-off value of 1.06 ng/ml, sensitivity of 95.8%, specificity of 92.1%, and the Youden indicator of 0.879, the negative and positive predictive values were 97.8% and 85.0% respectively, the negative and positive likelihood ratios were 0.05 and 12.5 respectively, and all significantly higher than that of CRP, IL-6 and SAA. It is concluded that for patients with hematologic malignancy combined with febrile neutropenia and bacterial infection, the diagnostic value of serum PCT is superior to that of immune inflammatory factors (CRP, IL-6 and SAA), the PCT can predict the bacterium infection, provide laboratory evidence for rational antimicrobial drug usage and mortality reduction.
Adult ; Bacteremia ; diagnosis ; etiology ; C-Reactive Protein ; metabolism ; Calcitonin ; blood ; Calcitonin Gene-Related Peptide ; Febrile Neutropenia ; complications ; microbiology ; Female ; Hematologic Neoplasms ; complications ; microbiology ; Humans ; Interleukin-6 ; blood ; Male ; Middle Aged ; Protein Precursors ; blood ; Retrospective Studies ; Serum Amyloid A Protein ; metabolism

BACKGROUND: Optimal blood culture performance is critical for successful diagnosis and treatment of sepsis. To understand the status of blood culture, we investigated several aspects of the procedure at 9 university hospitals. METHODS: The process of ordering blood culture sets and sampling volume for adults and children was investigated from January 2010 to April 2010, while the positive rate of detection and growth of skin contaminants were compared in 2009. Microbial growth in aerobic and anaerobic bottles was investigated prospectively. RESULTS: A majority of the hospitals used 2 sets of bottles for adults and 1 bottle for children. The average blood volume in each set was 7.7 mL for adults and 2.1 mL for children. The positive rate of microorganisms was 8.0%, and the isolation rate of the normal flora of the skin was 2.1%. Bacterial growth rates in aerobic and anaerobic bottles only were 31.8% and 24.5% respectively. CONCLUSIONS: Ordering blood culture sets and sampling volumes did not comply with CLSI guidelines. However, the rate of positive cultures and skin contamination rates were acceptable. Anaerobic bottles are useful in enhancing the yield of microorganisms.
Adult ; Bacteremia/blood/*microbiology ; Bacteria, Aerobic/isolation & purification ; Bacteria, Anaerobic/isolation & purification ; Blood/microbiology ; Child ; Hospitals, University ; Humans ; Prospective Studies ; Republic of Korea ; Skin/microbiology

BACKGROUND/AIMS: The purpose of this study was to evaluate the value of initial C-reactive protein (CRP) as a predictor of clinical outcome and to investigate whether follow-up CRP measurement is useful for the prediction of the clinical outcome of bloodstream infections in patients with liver cirrhosis (LC), whose CRP production in response to infection may be attenuated. METHODS: A retrospective, observational study including 202 LC patients with Escherichia coli or Klebsiella pneumoniae bacteremia was conducted to assess the usefulness of serial CRP measurements in predicting clinical outcome in LC patients. The CRP ratio was defined as the ratio of the follow-up CRP level to the initial CRP level. RESULTS: The overall 30-day mortality rate of the study population was 23.8% (48/202). In the multivariate analysis, advanced age (> or = 70 years), healthcare-associated or nosocomial infections, model for end-stage liver disease (MELD) score of > or = 30, and initial body temperature of < 37degrees C were significant factors associated with mortality (all p < 0.05). No association between initial CRP level and mortality was found. In a further analysis including 87 evaluable cases who had repeated CRP measurements at day 4 and/or 5, a CRP ratio of > or = 0.7 was found to be a significant factor associated with mortality (odds ratio, 19.12; 95% confidence interval, 1.32 to 276.86; p = 0.043) after adjusting for other confounding variables. CONCLUSIONS: Initial CRP level did not predict mortality of sepsis in LC patients. However, serial CRP measurements during the first week of antimicrobial therapy may be useful as a prognostic factor for mortality in LC patients.
Adult ; Age Factors ; Aged ; Aged, 80 and over ; Anti-Infective Agents/therapeutic use ; Bacteremia/drug therapy/*immunology/microbiology/mortality ; Biological Markers/blood ; C-Reactive Protein/*metabolism ; Chi-Square Distribution ; Escherichia coli Infections/drug therapy/*immunology/microbiology/mortality ; Female ; Humans ; Klebsiella Infections/drug therapy/*immunology/microbiology/mortality ; Klebsiella pneumoniae/*isolation & purification ; Liver Cirrhosis/complications/*immunology/mortality ; Logistic Models ; Male ; Middle Aged ; Odds Ratio ; Predictive Value of Tests ; Republic of Korea ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Time Factors ; Treatment Outcome