Clinical and Economic Evaluation of Blood Culture Whole Process Optimisation in Critically Ill Adult Patients With Positive Blood Cultures.

OBJECTIVES: Optimising blood culture processing is important to ensure that bloodstream infections are accurately diagnosed while minimising adverse events caused by antibiotic abuse. This study aimed to evaluate the impact of optimised blood culture processes on antibiotic use, clinical outcomes and economics in intensive care unit (ICU) patients with positive blood cultures. METHODS: From March 2020 to October 2021, this microbiology laboratory implemented a series of improvement measures, including the clinical utility of Fastidious Antimicrobial Neutralization (FAN® PLUS) bottles for the BacT/Alert Virtuo blood culture system, optimisation of bottle reception, graded reports and an upgraded laboratory information system. A total of 122 ICU patients were included in the pre-optimisation group from March 2019 to February 2020, while 179 ICU patients were included in the post-optimisation group from November 2021 to October 2022. RESULTS: Compared with the pre-optimisation group, the average reporting time of identification and antimicrobial sensitivity was reduced by 16.72 hours in the optimised group. The time from admission to targeted antibiotic therapy within 24 hours after receiving both the Gram stain report and the final report were both significantly less in the post-optimisation group compared with the pre-optimisation group. The average hospitalisation time was reduced by 6.49 days, the average antimicrobial drug cost lowered by $1720.85 and the average hospitalisation cost by $9514.17 in the post-optimisation group. CONCLUSIONS: Optimising blood culture processing was associated with a significantly increased positive detection rate, a remarkable reduction in the length of hospital stay and in hospital costs for ICU patients with bloodstream infections.

Risk Factors and Predictive Nomogram for Carbapenem-Resistant Klebsiella pneumoniae in Children in a Grade 3 First-Class General Hospital in Central China.

Background: This study determined risk factors for Carbapenem-resistant Klebsiella pneumoniae (CRKP)in children admitted to a grade 3 first-class general hospital and developed an individualized line graph predictive model. Methods: The clinical data of 185 children infected with Klebsiella pneumoniae from January 2015 to December 2019 were analyzed retrospectively. Patients were grouped according to carbapenem resistance: CRKP group (50 cases) and CSKP (carbapenem-sensitive Klebsiella pneumoniae) group (135 cases). Risk factors for CRKP in children were screened by logistic regression analysis. The predictive model was established using R software and validated using the Bootstrap method. Results: Age (odds ratio [OR]=0.104, 95% confidence interval [CI]: 0.026-0.408), intensive care unit admission (OR =2.829, 95% CI: 1.138-7.030), mechanical ventilation (OR =7.510, 95% CI: 3.140-17.961), surgery history (OR =5.005, 95% CI: 1.507-16.618) and glucocorticoid (OR =0.235, 95% CI: 0.099-0.557) were independent risk factors for CRKP in children (P < 0.05), The total risk score of each factor was 362.5, and the risk rate was 0.1-0.9. In receiver-operating characteristic curve analysis, the area under the curve of CRKP predicted by the total risk score was 0.872 (95% CI=0.844-0.901; P < 0.001). The correction curve indicated that the consistency between the observed value and the predicted value was good. Discussion and Conclusion: This study successfully established a model based on the risk factors, with high accuracy and good predictive value for CRKP in children. Hospitals should take necessary preventive measures against the risk factors for drug-resistant bacteria, such as optimizing the configuration of ICU space, timely isolation of infected children, and adequate disinfection of ICU equipment. Which may reduce CRKP infection rate.

Metagenomic Next-Generation Sequencing Is Highly Efficient in Diagnosing Pneumocystis Jirovecii Pneumonia in the Immunocompromised Patients.

Purposes: To explore the value of metagenomic next-generation sequencing (mNGS) in diagnosing pneumocystis jiroveciipneumonia (PJP) in the immunocompromised patients. Methods: Data of 122 patients with PJP in an immunosuppressed state and 67 non-PJP patients were collected. The diagnostic efficacy of mNGS was compared with the conventional methods, including Gomori methenamine silver (GMS) staining and serum (1,3)-ß-D-glucan (BDG). Changes of anti-microbial therapy for patients with PJP based on mNGS results were also reviewed. Results: The diagnostic sensitivity of mNGS to PJP was higher than that of GMS and BDG (100% vs. 15 and 74.5%, p < 0.001). The diagnostic specificity (91.%) was lower than that of GMS (100%), and similar with BDG (89.6%). In addition to P. jirovecii, mNGS revealed co-pathogens like human ß-herpesvirus 5, human γ-pesvirus 4, and some other opportunistic pathogens. The reads of mNGS were remarkably higher in BALF than in blood samples. Initial antimicrobial treatment was modified in 89.3% patients based on the mNGS results, and 74 cases (60.7%) were treated with anti-P. jirovecii therapy. Conclusion: mNGS is highly efficient in diagnosing PJP and good at identifying pathogens in mixed infections.

Three-month outcomes of recovered COVID-19 patients: prospective observational study.

AIMS: A novel coronavirus SARS-CoV-2 has resulted in an ongoing global pandemic of Coronavirus disease 2019 (COVID-19). However, the outcomes of recovered patients have not been well defined. METHODS: This is a prospective observational follow-up study of survivors with COVID-19 from a designated tertiary center in Hefei, China. We examined chest computed tomography (CT) scanning, pulmonary function, 6-min walk distance (6MWD), and 36 item Short Form General Health Survey (SF-36). RESULTS: Among 81 enrolled patients, 62 (77%) patients and 61 (75%) patients, respectively, completed 1-month and 3-month follow-ups. Abnormal CT findings were still present in 73% of patients at 1 month and 54% at 3 months, whereas chest CT scan scores improved progressively at 1-month (5.0 ± 5.1) and 3-month follow up (3.0 ± 4.5) compared with that during hospitalization (11 ± 6.8). Mild restrictive pulmonary impairment was detected in 11% and 10% of patients at 1-month and 3-month follow up, respectively. The 6MWD was 523 ± 77 m in male patients and 484 ± 58 m in female patients, which was significantly lower than in healthy controls (606 ± 68 m, 568 ± 78 m, p < 0.001). SF-36 scores were significantly impaired in the domains of role physical (RP), role emotional (RE), and social functioning (SF) compared with the normal age-matched population. RP was improved at 3-month compared with 1-month follow up in the 41-64 years group (p < 0.01). Multivariable analysis showed that older age (over 40 years) and steroid administration during hospitalization were independently associated with worse chest CT scores at 3-month follow up. CONCLUSIONS: At 3 months, chest CT abnormalities were present in one half of COVID-19 survivors and worse chest CT scores were independently associated with older age and steroid administration during hospitalization. Residual pulmonary function impairments were modest, whereas exercise capacity and SF-36 scores were significantly lower than the general population. Support program and further follow-up evaluations may be needed.The reviews of this paper are available via the supplemental material section.

A Comparative Analysis of Serum IgG4 Levels in Patients With IgG4-Related Disease and Other Disorders.

OBJECTIVE: Elevated serum IgG4 levels are an important hallmark for diagnosing IgG4-related disease (IgG4-RD) but can also be found and reported in other diseases. The present study intended to compare the serum IgG4 levels in both IgG4-RD and non-IgG4-RD and determine the serum IgG4 levels in patients with IgG4-RD before and after glucocorticoid therapy. METHODS: The study included 323 patients from Anhui Medical University Affiliated Provincial Hospital (China) and was conducted from July 2014-January 2016. A total of 25 patients were eventually diagnosed as having IgG4-RD, according to the IgG4-RD diagnostic criteria. Our study also included 108 patients with connective tissue disease, 94 patients with pancreatic lesions, 66 patients with bile duct lesions, 13 patients with carcinoma of the duodenal papilla and 20 control participants. The assay for serum IgG4 detection was peformed using the nephelometric method. RESULTS: Elevated levels of serum IgG4 (>1.35g/L) were detected in all patients with IgG4-RD, and reduced levels of serum IgG4 (<1.35g/L) were found in all patients with non-IgG4-RD. The serum IgG4 level in patients with IgG4-RD after glucocorticoid therapy was significantly lower than that before glucocorticoid therapy (t = 2.426, P = 0.04). CONCLUSIONS: High levels of IgG4 were observed in IgG4-RD. However, a diagnosis of IgG4 disease can not only be dependent on the detection of elevated serum IgG4 levels but also may need clinical manifestations, serology, histopathology and other comprehensive information for verification.

Role of Rot in bacterial autolysis regulation of Staphylococcus aureus NCTC8325.

Autolysis is an important process in cell wall turnover in Staphylococcus aureus, performed by several peptidoglycan hydrolases or so-called autolysins and controlled by many regulators. Rot is a global regulator that regulates numerous virulence genes, including genes encoding lipase, hemolysins, proteases and genes related to cell surface adhesion. The aim of our study was to determine whether Rot has the ability to regulate autolysis. We compared Triton-X-100-induced autolysis of S. aureus NCTC8325 and its rot knock-out mutant. We found that the rot mutant showed increased autolysis rates. By examining the transcript level of several autolysins and some known regulators responsible for regulating autolysis using real-time RT-PCR assays, we found that transcription of two autolysins (lytM, lytN) and one regulatory operon (lrgAB) was changed in the rot mutant. An in vitro approach was undertaken to determine which of these genes are directly controlled by Rot. Rot proteins were overproduced in Escherichia coli and purified. Gel mobility shift DNA binding assays were used and showed that in-vitro-purified Rot can directly bind to the promoter region of lytM, lytN, lrgA and lytS. We also tested biofilm formation of the rot mutant, and it showed enhancement in biofilm formation. Taken together, our results reveal that Rot affects autolysis by directly regulating autolysins LytM and LytN, and, via a regulatory system, LrgAB.

Identification of two novel esterases from a marine metagenomic library derived from South China Sea.

The demand for novel biocatalysts is increasing in modern biotechnology, which greatly stimulates the development of powerful tools to explore the genetic resources in the environment. Metagenomics, a culture independent strategy, provides an access to valuable genetic resources of the uncultured microbes. In this study, two novel esterase genes designated as estA and estB, which encoded 277- and 328-amino-acid peptides, respectively, were isolated from a marine microbial metagenomic library by functional screening, and the corresponding esterases EstA and EstB were biochemically characterized. Amino acid sequence comparison and phylogenetic analysis indicated that EstA together with other putative lipolytic enzymes was closely related to family III, and EstB with its relatives formed a subfamily of family IV. Site-directed mutagenesis showed that EstA contained classical catalytic triad made up of S146-D222-H255, whereas EstB contained an unusual catalytic triad which consisted of S-E-H, an important feature of the subfamily. EstA exhibited habitat-specific characteristics such as its high level of stability in the presence of various divalent cations and at high concentrations of NaCl. EstB displayed remarkable activity against p-nitrophenyl esters and was highly stable in 30% methanol, ethanol, dimethylformamide, and dimethyl sulfoxide, making EstB a potential candidate for industrial applications.