Objective To summarize the epidemiological and clinical features of infectious diseases of the central nervous system(CNS)by a single-center analysis.Methods A retrospective analysis was conducted on the data of 1247 cases of CNS infectious diseases diagnosed and treated in the First Medical Center of PLA General Hospital from 2001 to 2020.Results The data for this group of CNS infectious diseases by disease type in descending order of number of cases were viruses 743(59.6％),Mycobacterium tuberculosis 249(20.0％),other bacteria 150(12.0％),fungi 68(5.5％),parasites 18(1.4％),Treponema pallidum 18(1.4％)and rickettsia 1(0.1％).The number of cases increased by 177 cases(33.1％)in the latter 10 years compared to the previous 10 years(P<0.05).No significant difference in seasonal distribution pattern of data between disease types(P>0.05).Male to female ratio is 1.87︰1,mostly under 60 years of age.Viruses are more likely to infect students,most often at university/college level and above,farmers are overrepresented among bacteria and Mycobacterium tuberculosis,and more infections of Treponema pallidum in workers.CNS infectious diseases are characterized by fever,headache and signs of meningeal irritation,with the adductor nerve being the more commonly involved cranial nerve.Matagenomic next-generation sequencing improves clinical diagnostic capabilities.The median hospital days for CNS infectious diseases are 18.00(11.00,27.00)and median hospital costs are ￥29,500(￥16,000,￥59,200).The mortality rate from CNS infectious diseases is 1.6％.Conclusions The incidence of CNS infectious diseases is increasing last ten years,with complex clinical presentation,severe symptoms and poor prognosis.Early and accurate diagnosis and standardized clinical treatment can significantly reduce the morbidity and mortality rate and ease the burden of disease.

Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO₂), fine particulate matter (PM_2.5), and inhalable particulate matter (PM₁₀) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min⁻¹, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO₂ concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM_2.5, and PM₁₀ in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO₂, but 0% for humidity. The overall median (P₂₅, P₇₅) total bacteria count was 177 (138,262) CFU·m⁻³. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.

Natural products are important sources of drug discovery. However, the traditional methods of extraction and isolation, as well as chemical synthesis for obtaining natural products are associated with issues such as operational complexity, high costs, low efficiency, and environmental pollution. Constructing microbial cell factories through synthetic biology methods to produce medicinal natural products has the advantages of high efficiency, low cost, and environmental protection. Nevertheless, the scope and yield improvement of the products are limited by the limitations of enzymes in microbial cell factories. Protein engineering is considered one of the most effective approaches to overcome these limitations. This article introduces commonly used methods of protein engineering technology and summarizes its specific applications in improving enzyme performance, modifying the enzymatic environment, and promoting the development of synthetic biology tools in the field of pharmaceutical natural product synthesis. Furthermore, it analyzes the current bottlenecks and challenges in protein engineering and looks forward to its future application prospects, offering insights for the development and practical use of protein engineering technology.

ObjectiveTo understand the process and influencing factors affecting the utilization of influenza vaccination services and vaccination decision-making among the elderly in Shanghai, to explore the delivery of influenza vaccination services and the difficulties faced by the health service system, and to provide guidance for optimizing immunization strategies. MethodsBased on the vaccine hesitancy determinants matrix, semi-structured personal interviews were conducted with stakeholders involved in influenza vaccination services in Shanghai from January to February 2024, using a purposive sampling method. Participants were included until thematic saturation was achieved. Interview data were audio-recorded, transcribed, coded, and organized using NVivo 20 software, and analyzed using the thematic framework method. ResultsA total of 25 interviewees were included, including 9 medical staff, 12 elderly people aged 60 and above, and 4 family members. The study found that Shanghai had a well-managed and standardized influenza vaccination service. However, the promotion of vaccine-related information at the grassroots level was passive and limited. Out-of-pocket payment of the vaccine and cultural beliefs of the elderly negatively impacted vaccination rates. Meanwhile, recommendations from family, friends, and medical staff facilitated vaccination, although the impact varied depending on the type of medical staff. Neighborhood committees in townships and streets played a crucial role in delivering vaccination information to the target population. Additionally, the internet, social media, and the COVID-19 vaccine had both positive and negative impacts on influenza vaccination. Strategic optimization of vaccination should prioritize price concessions, enhance publicity strategies, and improve awareness, professionalism, and willingness among medical and healthcare workers to recommend vaccination. ConclusionThe influenza vaccination service in Shanghai is well-managed and standardized. However, it is essential to consider the influence of family and other support systems on the elderly. It is also necessary to enhance the professionalism, service awareness, and willingness to recommend among the medical staff. Furthermore, systematic interventions and publicity efforts should be effectively integrated with social media and the functions of neighborhood committees.

Objective:To evaluate the effects of fine particle matter(PM2.5)and ozone(O3)com-bined exposure on adenosine triphosphate(ATP)amount and ATPase activities in nasal mucosa of Spra-gue Dawley(SD)rats.Methods:Twenty male SD rats were divided into control group(n=10)and exposure group(n=10)by random number table method.The rats were fed in the conventional clean environment and the air pollutant exposure system established by our team,respectively,and exposed for 208 d.During the exposure period,the concentrations of PM2 5 and O3 in the exposure system were moni-tored,and a comprehensive assessment of PM2 5 and O3 in the exposure system was conducted by combi-ning self-measurement and site data.On the 208 d of exposure,the core,liver,spleen,kidney,testis and other major organs and nasal mucosal tissues of the rats were harvested.Each organ was weighed and the organ coefficient calculated.The total amount of ATP was measured by bioluminescence,and the ac-tivities of Na+-K+-ATPase and Ca2+-ATPase were detected by spectrophotometry.The t test of two inde-pendent samples was used to compare the differences among the indicator groups.Results:From the 3rd week to the end of exposure duration,the body weight of the rats in the exposure group was higher than that in the control group(P＜0.05),and there was no significant difference in organ coefficients be-tween the two groups.The average daily PM2 5 concentration in the exposure group was(30.68±19.23)μg/m3,and the maximum 8 h ozone concentration(O3-8 h)was(82.45±35.81)μg/m3.The chemi-luminescence value(792.4±274.1)IU/L of ATP in nasal mucosa of the rats in the exposure group was lower than that in the control group(1 126.8±218.1)IU/L.The Na+-K+-ATPase activity(1.53±0.85)U/mg in nasal mucosa of the rats in the exposure group was lower than that in the control group(4.31±1.60)U/mg(P＜0.05).The protein content of nasal mucosa in the control group and the exposure group were(302.14±52.51)mg/L and(234.58±53.49)mg/L,respectively,and the ac-tivity of Ca2+-ATPase was(0.81±0.27)U/mg and(0.99±0.73)U/mg,respectively.There was no significant difference between the groups.Conclusion:The ability of power capacity decreased in the rat nasal mucossa under the sub-chronic low-concentration exposure of PM2 5 and O3.

Objective Little is known about the association between whole-blood nicotinamide adenine dinucleotide(NAD+)levels and nabothian cysts.This study aimed to assess the association between NAD+levels and nabothian cysts in healthy Chinese women. Methods Multivariate logistic regression analysis was performed to analyze the association between NAD+levels and nabothian cysts. Results The mean age was 43.0±11.5 years,and the mean level of NAD+was 31.3±5.3 μmol/L.Nabothian cysts occurred in 184(27.7%)participants,with single and multiple cysts in 100(15.0%)and 84(12.6%)participants,respectively.The total nabothian cyst prevalence gradually decreased from 37.4%to 21.6%from Q1 to Q4 of NAD+and the prevalence of single and multiple nabothian cysts also decreased across the NAD+quartiles.As compared with the highest NAD+quartile(≥34.4 μmol/L),the adjusted odds ratios with 95%confidence interval of the NAD+Q1 was 1.89(1.14-3.14)for total nabothian cysts.The risk of total and single nabothian cysts linearly decreased with increasing NAD+levels,while the risk of multiple nabothian cysts decreased more rapidly at NAD+levels of 28.0 to 35.0 μmol/L. Conclusion:Low NAD+levels were associated with an increased risk of total and multiple nabothian cysts.

Objective To investigate whether Heshouwuyin can delay the aging of Leydig cells in rat testis through DNA methyltransferase 1(DNMT1).Methods Totally 40 male Wistar rats were randomly divided into 4 groups,with 10 rats in each group.Immunohistochemistry was used to detect the expression levels of DNMT1 in testis tissue of rats.Testosterone content in serum of rats in each group was detected by ELISA test.A rat Leydig cell aging model was established by free radical oxidative damage.DNMT1 was knocked down by lentivirus in Leydig cells,and the cell senescence status and the testosterone content and testosterone synthesis key enzyme 3β-hydroxysteroid dehydrogenase(3β-HSD),cytochrome P450 family member 11A1(CYP11A1)content secreted by cells were detected by β-galactosidase(β-GAL)staining,immunofluorescenct staining and ELISA.Results Compared with the young control group(YCG),the expression of P16 protein and the positive rate of β-GAL in the testis tissue of rats in the natural aging group(NAG)increased significantly,and the expression of DNMT1 and serum testosterone levels decreased(P＜0.05).However,after Heshouwuyin intervention,the expression of P16 protein and the positive rate of β-GAL in the testis of aging rats were reduced,and DNMT1 expression and the serum testosterone levels increased(P＜0.05).The same trend was observed in Leydig cells.Knockdown of DNMT1 in Leydig cells,β-GAL positivity and P16 protein expression increased significantly,and testosterone secretion and testosterone synthesis key enzymes 3β-HSD,CYP11A1 content from Leydig cells decreased significantly,compared with the normal control group(NCG)(P＜0.05).When Heshouwuyin was added,the above phenomenon was improved.Conclusion Heshouwuyin can delay the aging of rat Leydig cells through DNMT1.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.