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.

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 efficacy and safety of neoadjuvant therapy with trastuzumab and pertuzumab combined with taxane and platinum drugs (TCbHP) regimen for human epidermal growth factor receptor 2 (HER2)-positive breast cancer.Methods:A retrospective case series study was conducted. The clinical data of HER2-positive breast cancer patients who received neoadjuvant therapy with 21-day TCbHP regimen and completed subsequent surgery in 11 tertiary-level hospitals in Hebei Province from June 2019 to December 2021 were retrospectively analyzed, and the total pathological complete remission (tpCR) rate, the incidence of grade ≥3 adverse events, and the completion rate of the established regimen were statistically analyzed.Results:A total of 78 female patients were included and the median age [ M ( Q1, Q3)] was 54.0 years (48.5 years, 57.5 years). The tpCR rate was 64.1% (50/78). Subgroup analysis showed that the tpCR rate in the HER2 immunohistochemistry (IHC)+++ group was higher than that in the HER2 IHC++ and fluorescence in situ hybridization-positive group [68.6% (48/70) vs. 25.0% (2/8)], and the difference was statistically significant ( χ2 = 4.18, P = 0.041); the tpCR rate in the hormone-receptor negative group was higher than that in the hormone-receptor positive group [81.8% (27/33) vs. 51.1% (23/45)], and the difference was statistically significant ( χ2 = 7.80, P = 0.005); the tpCR rate in the albumin-bound paclitaxel group was higher than that in the docetaxel group [72.3% (34/47) vs. 48.3% (14/29)], and the difference was statistically significant ( χ2 = 4.46, P = 0.035). The incidence of ≥ grade 3 adverse reactions was 12.8% (10/78) in 78 patients, and the completion rate of the established regimen was 92.3% (72/78). Conclusions:Neoadjuvant therapy with TCbHP regimen for HER2-positive breast cancer shows a definite efficacy, good safety and tolerance.

Human epidermal growth factor receptor 2 (HER2) is an important therapeutic target for breast cancer in recent years. The emergence of targeted drugs represented as trastuzumab has drastically improved the prognosis of HER2-positive breast cancer patients. Antibody-drug conjugates (ADC) such as trastuzumab deruxtecan (T-DXd) have shown the obvious therapeutic efficacies in breast cancer with HER2 low expression recently, which has become a research hotpot. With the deepening of the research, new views of the detection of HER2 and the molecular subtypes of breast cancer are proposed, besides, the concept of ultra-low HER2 expression is also proposed by some scholars. Several studies have explored the application of ADC and new treatments in HER2 low expression breast cancer. This paper reviews the definition, the detection and determination, clinicopathologic characteristics and treatment progress of breast cancer with HER2 low expression.

Objective: Cognition impairments are considered as a fundamental characteristic of severe mental disorders (SMD). Recent studies suggest that hyperprolactinemia may exert a detrimental influence on cognitive performance in patients with SMD. The objective of this study was to investigate the correlation between serum prolactin levels and cognitive function in female individuals diagnosed with SMD. Methods: We conducted a study on 294 patients with SMD and 195 healthy controls, aged between 14 to 55 years old. Cognitive function was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), while prolactin levels were measured in serum. Descriptive analysis and comparative analysis were performed to compare cognitive function and prolactin levels between groups, and linear regression models were used to explore the relationship between prolactin and cognitive function. Results: Compared to the healthy control, individuals with SMD exhibited significantly higher levels of prolactin, while scoring lower on RBANS total and every index scores. Furthermore, a negative association between prolactin levels and cognitive function (RBANS total index score, attention, and delayed memory) was observed in SMD patients. Importantly, this inverse correlation between prolactin and cognition function (RBANS total index score, total scale score, and attention) persisted in patients who were not taking medications that could potentially influence serum prolactin levels. Conclusion Our study reveals a significant correlation between elevated prolactin levels and cognitive impairment in female patients with SMD, underscoring the importance of monitoring prolactin levels in order to prevent cognitive deterioration among female SMD patients.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Humans ; Staphylococcus lugdunensis/genetics* ; Peptides, Cyclic ; Chromosomes ; Operon/genetics* ; Staphylococcal Infections/genetics* ; Bacterial Proteins/genetics* ; Anti-Bacterial Agents

Objective:To investigate the bacterial composition and antimicrobial resistance profile of clinical isolates from bloodstream infections in China.Methods:The clinical bacterial strains isolated from blood culture were collected during January 2020 to December 2020 in member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS). Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute(CLSI, USA). WHONET 5.6 was used to analyze data.Results:During the study period, 10 043 bacterial strains were collected from 54 hospitals, of which 2 664 (26.5%) were Gram-positive bacteria and 7 379 (73.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (38.6%), Klebsiella pneumoniae (18.4%), Staphylococcus aureus (9.9%), coagulase-negative Staphylococci (7.5%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.3%), Enterobacter cloacae (2.8%), Enterococcus faecalis (2.6%), Acinetobacter baumannii (2.4%) and Klebsiella spp (1.8%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 27.6% and 74.4%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci were detected. More than 95% of Staphylococcus aureus were sensitive to rifampicin and SMZco. No vancomycin-resistant Enterococci strains were detected. Extended spectrum β-lactamase (ESBL) producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 48.4%, 23.6% and 36.1%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.3% and 16.1%, respectively; 9.6% of carbapenem-resistant Klebsiella pneumoniae strains were resistant to ceftazidime/avibactam combination. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii. The prevalence rate of carbapenem-resistance of Pseudomonas aeruginosa was 23.2%. Conclusions:The surveillance results in 2020 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen, and ESBL-producing strains declined while carbapenem-resistant Klebsiella pneumoniae kept on high level. The proportion and the prevalence of carbapenem-resistant Pseudomonas aeruginosa were on the rise slowly. On the other side, the MRSA incidence got lower in China, while the overall prevalence of vancomycin-resistant Enterococci was low.

Objective The effect of different doses of ethylnitrosourea(ENU)and cyclophosphamide(CP)on the loss rate of CD59 on peripheral blood erythrocytes was explored to optimize the detection method of Pig-a gene mutation. Methods According to the weight and loss rate of CD59 on peripheral blood erythrocytes,rats were divided into 4 groups:the control group,CP 40 mg/kg group,ENU 10 mg/kg group and ENU 40 mg/kg group(n=6). The control group was injected i.p. with PBS,other groups were injected i.p. with corresponding solutions. The body weight of rats on days 0,7,14,21, 28, 42 and 56 were recorded. At the same time, blood samples were collected and incubated with antibodies,and the loss rate of RBCCD59-was detected by flow cytometry. Results Compared with the control group, at different time points, the body weight and weight gain of ENU 10 mg/kg group and ENU 40 mg/kg group had no statistically significant difference(P > 0.05),while those in the CP 40 mg/kg group were significantly decreased(P <0.05). The loss rate of RBCCD59-was significantly increased in the CP 40 mg/kg group at 28,42 and 56 days, ENU 10 mg/kg group at 42 and 56 days,and ENU 40 mg/kg group at 7,14,21,28,42 and 56 days,(P < 0.05). The results showed a dose-response relationship. Conclusions Under the conditions of this Pig-a mutation detection method,ENU is superior to CP on raising loss rate of RBCCD59-,ENU 40 mg/kg is better than 10 mg/kg,and 28 days is suitable as the test period.

BACKGROUND:Failure rate is higher in patients with osteonecrosis of femoral head than in osteoarthritis patients after primary total hip arthroplasty, especial y acetabular prosthesis. Bone mineral density around the prosthesis is a key factor for quality of life of the prosthesis. OBJECTIVE:To observe the difference in periprosthetic bone mineral density between patients with osteonecrosis of the femoral head and osteoarthritis patients and the exact location of differences after primary total hip arthroplasty. METHODS:Fifty patients with osteonecrosis of femoral head and fifty osteoarthritis patients were enrol ed in this study. Dual energy X-ray absorptiometry examination was used to compare bone mineral density 5 years after total hip arthroplasty. In accordance with De Lee’s and Charnley’s methods, images of acetabulum were divided. The bone mineral density of different areas of the acetabulum was compared between the two groups. RESULTS AND CONCLUSION:(1) Periprosthetic bone mineral density:Bone mineral density in the lower part and upper part of the acetabulum was significantly lower in the osteonecrosis group than in the osteoarthritis group (P<0.05). No significant difference in bone mineral density in the middle of the acetabulum was detected between the two groups. (2) Results confirmed that the bone mineral density in the lower and the upper parts of the acetabular component was significantly lower in patients with osteonecrosis of femoral head than in patients with osteoarthritis.