Objective:To evaluate the value of Treponema pallidum ( Tp)-specific antibody index in the diagnosis, staging, and typing of neurosyphilis (NS). Methods:Fifty patients diagnosed with NS at the West China Hospital of Sichuan University from March 2020 to December 2022 were recruited as the experimental group, and 50 non-NS syphilis patients were enrolled during the same period as the control group. Cerebrospinal fluid (CSF) and matched serum samples along with clinical data were collected. Clinical and Laboratory Standards Institute (CLSI) EP06-Ed2 file was used to analyze the linear range of electrochemiluminescence immunoassay for Tp-specific antibody detection, and the Tp antibody index was calculate for all subjects. The correlation of Tp antibody index, IgG index, IgG synthesis rate, and albumin quotient with other clinical indicators was evaluated by the coefficient of correlation, and the diagnostic efficacy of these indicators in NS was analyzed using the receiver operating characteristic (ROC) curve. Results:All the deviations from linearity of electrochemiluminescence immunoassay for detecting Tp antibodies in serum and CSF samples were within the allowable deviation from linearity. Compared with the non-NS group, the NS group showed a significant increase in the Tp antibody index ( P<0.05), with no significant differences observed among the groups of different subtypes, severity, or receiving treatment or not ( P>0.05). Tp antibody index, IgG index, and IgG synthesis rate were positively correlated with serum Tp antibody, CSF Tp antibody, trace protein, and nucleated cell count ( P<0.05). Taking 14.99 as the cut-off value for NS diagnosis, the diagnostic sensitivity of Tp antibody index was 74.0% (95%CI: 60.5%-84.1%), and the specificity was 94.0% (95%CI: 83.8%-98.4%), with the area under the ROC curve of 0.897, which was larger than that of albumin quotient, IgG index, and IgG synthesis rate. Conclusions:This study finds a significant increase in the Tp antibody index in NS patients with good diagnostic sensitivity and specificity, providing reference for the diagnosis of NS.

Objective: To retrospectively analyze the distribution of non-fermentative bacteria causing bloodstream infection in hospitalized patients in Sichuan Province and their drug susceptibility to common antibiotics for better understanding their epidemiological characteristics. Methods: From January 1, 2015 to December 31, 2017, all of the non-fermentative bacteria isolated from patients with bloodstream infection in nine hospitals in Sichuan Province were collected. Species distribution and drug resistance test results were retrospectively analyzed. Results: A total of 6 291 strains of pathogenic bacteria were isolated, including 3 674 strains of gram-negative bacteria (58.4%) and 2 617 strains of gram-positive bacteria (41.6%). The gram-positive bacteria were 1 895 strains of Staphylococcus (30.1%), 372 strains of Streptococcus (5.9%), 317 strains of Enterococcus (5.1%) and 33 strains of other gram-positive bacteria (0.5%). The gram-negative bacteria were 3 191 Enterobacteriaceae strains (50.7%), 389 non-fermentative strains (6.2%) and 94 other gram-negative strains (1.5%). The isolated non-fermentative bacteria were mainly Pseudomonas aeruginosa (136 strains, 35.0%), Acinetobacter baumannii (126 strains, 32.0%) and Stenotrophomonas maltophilia (33 strains, 8.5%). There were 167 (42.9%), 112 (28.8%) and 82 (21.1%) non-fermentative bacteria isolated in internal medicine departments, ICUs and surgery departments, respectively. The drug resistance rates of Pseudomonas aeruginosa to cefepime, ciprofloxacin and gentamicin were 16.5%, 10.7% and 9.9%, respectively. Carbapenems-resistant Pseudomonas aeruginosa (CR-PA) accounted for 13.6%. No polymyxin-resistant Pseudomonas aeruginosa was found. The resistance rates of Acinetobacter baumannii to all antibiotics were over 30% except for minocycline and polymyxin and 75.7% of carbapenem-resistant Acinetobacter baumannii (CR-AB) were isolated. The drug resistance rates to levofloxacin, trimethoprim/sulfamethoxazole and ceftazidime were 0%, 0% and 37.0% in Stenotrophomonas maltophilia isolates and 10.5%, 4.2% and 19% in Burkholderia cepacia isolates, respectively. Conclusions Non-fermentative bacteria causing 6.2% of bloodstream infection in Sichuan, mainly by Pseudomonas aeruginosa and Acinetobacter baumannii. There were significant differences in the isolation rate of non-fermentative bacteria in different departments and most of the strains were isolated in internal medicine departments. The detection rate of Acinetobacter baumannii with multiple drug resistance was high, while other non-fermentative bacteria had good sensitivity to antibiotics.