Objective : To investigate the epidemiological characteristics of severe fever with thrombocytopenia syndrome (SFTS) in Dongyang City, Zhejiang Province from 2017 to 2022, so as to provide insights into SFTS prevention and control. Methods: Data pertaining to patients with SFTS in Dongyang City from 2017 to 2022 were collected from Notifiable Infectious Disease Reporting System of Chinese Disease Prevention and Control Information System. The epidemiological and clinical characteristics of patients with SFTS were descriptively analyzed, and the trends in incidence of SFTS was evaluated using annual percent change (APC). Results: A total of 32 SFTS cases were reported in Dongyang City from 2017 to 2022, with mean annual incidence of 0.63/105, and 8 cases died, with a fatality rate of 25.00%. The incidence of SFTS appeared a tendency towards a rise from 2017 to 2022 (APC=40.697%, P<0.05). The male to female ratio of SFTS cases was 0.78∶1, and farmer was the predominant occupation (31 cases, 96.88%). SFTS predominantly occurred among individuals at ages of 51 to 69 years (20 cases, 62.50%), and the incidence peaked during the period between March and May and between July and August (28 cases, 87.50%). SFTS cases were reported in 11 out of the 18 townships (streets) in Dongyang City, with the highest number found in Zuocun Township (8 cases, 28.13%), and had the lowest platelet count of (41.46±5.19)×109 platelets/L, with the lowest count of (3.00 to 67.00) ×109 platelets/L. All the SFTS cases had a history of mountain forest and farmland activities 2 weeks prior to onset of the disease, and 5 cases (15.63%) had a history of tick bites. Conclusions The incidence of SFTS appeared a tendency towards a rise in Dongyang City from 2017 to 2022, and SFTS was highly prevalent in spring and summer, with high incidence among farmers. Intensified health education of SFTS is recommended among residents in high-incidence areas.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

The purpose of this study was to investigate the intervention effect and mechanism of Lycium barbarum leaves on letrozole-induced polycystic ovary syndrome (PCOS) mice. The PCOS model was prepared by letrozole combined with high-fat diet. After successful modeling, 40 mice were randomly divided into PCOS group, positive drug metformin group, low-dose Lycium barbarum leaves group, and high-dose Lycium barbarum leaves group. The corresponding drugs were given by gavage for 29 days. At the end of the experiment, the eyeballs were removed for blood collection and ovarian tissue was collected. The ovarian mass, fasting blood glucose (FBG), fasting insulin (FINS), testosterone (T), anti-Mullerian hormone (AMH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and estradiol (E₂) levels were measured in each group. The morphology of ovarian tissue was observed by hematoxylin-eosin staining, and the oocytes, cystic follicles and corpus luteum were counted. Cecal contents of mice were collected for analysis of intestinal flora composition and differential flora. The animal experiment process was approved by the Animal Ethics Committee of Nanjing University of Traditional Chinese Medicine. The results showed that the estrous cycle of PCOS mice was disordered. Compared with the PCOS group, the Lycium barbarum leaves group can significantly reduce the ovarian damage of mice, reduce the number of cystic dilated follicles, and normalize the estrous cycle. After the intervention of Lycium barbarum leaves, the levels of FBG, FINS, T, AMH, LH, FSH and LH/FSH were significantly decreased (P < 0.05), while the level of E₂ was significantly increased (P < 0.001). In addition, Lycium barbarum leaves can regulate the disorder of intestinal flora diversity in PCOS mice, increase the abundance of Bacteroidetes, and reduce the abundance of Firmicutes, Ileibacterium, Romboutsia and Faecalibaculum. In summary, Lycium barbarum leaves can play a therapeutic role in PCOS mice by improving insulin resistance, regulating reproductive hormone disorders and gut microbiota imbalance. It provides scientific basis and useful reference for the rational utilization and development of Lycium barbarum leaves.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective:To investigate the spectrum and antimicrobial resistance of major pathogens causing nosocomial infections in China during 2020-2021.Methods:A total of 1 311 non-duplicated nosocomial pathogens causing bloodstream infections (BSI, n=670), hospital-acquired pneumonia (HAP, n=394) and intra-abdominal infections (IAI, n=297) were collected from 10 teaching hospitals across China. The minimum inhibitory concentrations (MICs) of clinical common strains were determined using agar dilution or broth microdilution method. Interpretation of reults followed the CLSI M100-Ed33 criteria, with data analysis conducted using WHONET-5.6 software. The Chi-square test was used to compare rates. Results:The most prevalent pathogens causing BSI were Escherichia coli (21.2%, 142/670), Klebsiella pneumoniae (14.9%, 100/670) and Staphylococcus aureus (11.5%, 77/670); the most prevalent pathogens causing HAP were K. pneumoniae (27.7%, 109/394), Acinetobacter baumanii (22.1%, 87/394) and Pseudomonas aeruginosa (18.3%, 72/394). IN IAI, E. coli (24.3%, 60/247), Enterococcus faecium and K. pneumoniae (both 14.6%, 36/247) were dominated. All S. aureus strains were susceptible to tigecycline, linezolid, daptomycin and glycopeptides. Rates of methicillin-resistant S. aureus (MRSA) and coagulase-negative Staphylococcus (MRCNS) were 36.5% (42/115) and 74.5% (38/51), respectively. The rate of vancomycin-resistant E. faecium and E. faecalis was 3.3% (3/90) and 1.9% (1/53), respectively. The prevalence of extended-spectrum β-lactamase (ESBL) was 23.7% (58/245) in K. pneumonia and 60.5% (130/215) in E. coli.The rate of carbapenem-resistant K. pneumonia and E. coli was 29.8% (73/245) and 4.2% (9/215), respectively; the percentage of tigecycline-resistant K. pneumonia and E. coli was 1.6% (4/245) and 0, respectively; the rate of colistin-resistant K. pneumonia and E. coli was 1.6% (4/245) and 2.8% (6/215), respectively; the percentage of ceftazidime/avibactam-resistant K. pneumonia and E. coli was 2.0% (5/245) and 2.3% (5/215), respectively. The rate of carbapenem-resistant A. baumanii and P. aeruginosa was 76.7% (125/163) and 28.4% (33/116), respectively. A. baumanii showed low susceptibility to most antimicrobial agents except colistin (98.8%, 161/163) and tigecycline (89.6%, 146/163). Colistin, amikacin and ceftazidime/avibactam demonstrated high antibacterial activity against P. aeruginosa with susceptility rates of 99.1% (115/116), 94.0% (109/116) and 83.6% (97/116), respectively. Conclusions:The major pathogens of nosocomial infections were K. pneumonia, E. coli, A. baumanii, P. aeruginosa and S. aureus. Nosocomial Gram-negative pathogens exhibited high susceptibilities to tigecycline, colistin and ceftazidime/avibactam. Antimicrobial resistance in A. baumannii remains a significant challenge. The increasing prevalence of carbapenem-resistant Enterobacterales underscores the urgency of antibiotics rational applications and hospital infection controls.