Objective:Postoperative neurosurgical bacterial meningitis (PNBM) has been frequently reported, but fewer studies have focused on the contemporaneous comparison of clinical features of PNBM caused by different pathogenic bacteria. This study aimed to simultaneously investigate the clinical characteristics and outcomes of PNBM by Gram-positive bacterial(GPB) or Gram-negative bacterial (GNB) infection.Methods:Inpatients with PNBM at our institution were recruited between February 2013 and October 2023. These PNBM patients were categorized into two groups: GPB infection and GNB infection. Data from electronic medical records were collected and analyzed.Results:A total of 401 patients with PNBM were finally included, with 78 (19.5%) having GPB infections and 323 (80.5%)having GNB infection. The average age of the patients was 56 years, and 55.1% were male. Compared to the GPB group, PNBM patients with GNB infection had significantly higher SOFA and APACHE Ⅱ scores, higher proportions of hyperthermia (body temperature>39°C) and altered consciousness, increased ratios of postoperative cerebral hemorrhage or intracranial aneurysm, as well as greater needs for ICU treatment and mechanical ventilation (all P <0.05). The proportions of inflammatory indicators such as blood CRP and PCT≥2 ng/mL, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) were significantly higher in the GNB group (all P<0.05). In contrast, The concentrations of hemoglobin and albumin were substantially lower in this group(both P <0.05). Additionally, the cerebrospinal fluid in the GNB group showed significantly higher nucleated cell counts, protein concentration, and adenosine deaminase concentration, and but lower glucose level (all P <0.001). A total of 426 bacterial strains were isolated, with 343 strains (80.5%) being GNB and 83 strains (19.5%) being GPB. Among these, 25 (6.2%) patients had 2 or more gram-positive or gram-negative bacterial infections. The proportions of multidrug-resistant (MDR) bacteria and intrathecal treatment were higher in the GNB group (80.5% vs. 68.7%, 36.5% vs. 2.6%, respectively), while the ratio of correct empirical antibiotic treatment was significantly lower (30.3% vs. 80.0%) (all P <0.05). In terms of outcomes, the length of stay in the ICU was significantly longer in the GNB group [(median (interquartile range, IQR): 11.5 (5.25,22.75) vs. 17.0 (9.0,30.0), P <0.01)], and the rate of septic shock (9.3% vs. 2.6%), poor prognosis (GCS≤8 at discharge) (65.9% vs. 32.1%), and 28-day hospital mortality rate (34.4% vs. 10.3%) were significantly higher compared to the GPB group (all P <0.05). However, there were no differences in 7-day hospital mortality and total hospitalization time. Conclusions:Gram-negative bacterial infections are more prevalent than Gram-positive bacterial infections in PNBM, and they are also associated with more severe symptoms, abnormal cerebrospinal fluid findings, higher severity, and more treatment difficulty. Despite comparable short-term (7-day) mortality rates between Gram-positive and Gram-negative bacterial infections, Gram-negative bacterial infections result in higher medium- to long-term (14-day and 28-day) case-fatality rates among patients with post-neurosurgical bacterial meningitis and are associated with overall poorer prognosis, warranting greater attention from clinicians.

Objective To study the antifungal activity of N2 derivatives. Methods The anti-fungal activity of N2 compounds was investigated by micro-liquid dilution. Then the activity of N2 compounds on hyphal and biofilm formation was investigated. Results N2 compounds had significant antifungal activity against Candida albicans. It also expressed actively inhibitory effect on hyphal and biofilm formation. The mechanism of its fungicidal function was to damage the structure of candida albicans’ cell membrane and cell wall. Conclusion The results showed that N2 had obvious antifungal activity against Candida albicans., which provided a new idea for the development of antifungal drugs and the solution of antifungal drugs resistance.