Objective:To investigate the expression of coxsackievirus-adenovirus receptor (CAR) in thymic carcinoma and the relationship between CAR and the antitumor activity of oncolytic adenovirus H101.Methods:The expression of CAR in thymic carcinoma tissues and cells were detected by RT-qPCR and Western blot. H101 expression and virus titers in Bcap-37, MP59 and T1889 cells after infection were detected by RT-qPCR and 50% tissue culture infectious dose (TCID 50). The proliferation activity and apoptosis rates of T1889 cells infected with H101 at different multiplicity of infection (MOI) were detected by CCK-8 and flow cytometry. CAR expression in T1889 cells treated with different concentrations of trichostatin A (TSA), a histone deacetylase inhibitor, was detected. H101 expression and virus titers in the TSA-treated and H101-infected cells were detected. Cell activity was detected by CCK-8. The phosphorylation levels of MARK and ERK1/2 and the expression of CAR at protein level in TSA-treated or TSA+ TBHQ (ERK activator) treated cells were detected. Results:CAR expression at both mRNA and protein levels were significantly lower in thymic carcinoma tissues than in adjacent normal tissues ( P<0.01), and lower in MP59 and T1889 cells than in thymic epithelial cells (TEC) and Bcap-37 cells ( P<0.01). H101 expression in MP59 and T1889 cells and the titers of H101 in culture supernatants were significantly lower than those in Bcap-37 cells ( P<0.01). Compared with Bcap-37 cell, the activity of MP59 and T1889 cells was significantly increased and the apoptosis rates were significantly decreased 48 h after H101 infection ( P<0.01). The expression of CAR at both mRNA and protein levels in T1889 cells treated with different concentrations of TSA increased in a dose-dependent manner. When T1889 cells were treated with 0.25 μmol/L of TSA, the expression of H101 at mRNA level and H101 titers were significantly increased ( P<0.05); the phosphorylation levels of MAPK and ERK1/2 proteins were continuously decreased; the expression of CAR was continuously increased. Compared with the TSA treatment group, the expression of CAR at protein level in the TSA+ TBHQ treatment group decreased significantly ( P<0.01), and the p-ERK1/2/ERK1/2 ratio increased significantly ( P<0.01). Conclusions:TSA could up-regulate CAR expression in thymic carcinoma by inhibiting the MARK/ERK1/2 pathway, thereby enhancing the antitumor activity of H101.

Objective To evaluate the clinical application of Catalyst system in positioning patients during cervical cancer radiotherapy,and to analyze its correlation with the bladder volume and body mass index (BMI) of patients.Methods A total of 33 patients diagnosed with cervical cancer from July to December 2017 in our hospital were included in the study.All patients were auxiliary positioned by an optical surface imaging system (C-Pad Catalyst) before each treatment.The CBCT imaging was executed twice a week.The setup errors from Catalyst and CBCT in the anterior-posterior (AP),superior-inferior (SI) and leg-fight (LR) directions were recorded.Each patient's bladder volume and BMI were also recorded.Results The setup errors between Catalyst with masks and CBCT had the significant difference in SI (P＜0.05) and LR (P＜0.05).For Catalyst without masks,the setup errors with the bladder volume of 200-300 ml had the significant association in SI (R=-0.316,P＜0.05).For the bladder volume of＞300 ml,the setup errors for Catalyst with masks had the significant association in AP (R=-0.493,P＜0.05),and that without masks had the significant association in SI and LR (R=0.335,P＜0.05,R=-0.348,P＜0.05).For patients of＜25 kg/m2,setup errors for Catalyst with masks had the significant association with the BMI in LR (R=0.197,P＜0.05);for ≥ 25 kg/m2,that with masks had the significant association in AP and SI (R =0.818,P＜0.05;R=-0.498,P＜0.05),that without masks had the significant association in AP and LR (R=0.652,P＜0.05;R=-0.558,P＜0.05).Conclusion Unlike CBCT system,the patient positioning by Catalyst system was easily affected by the bladder volume and BMI of patients.

Objective: To investigate the correlation between skin elasticity and setup error in optical surface image-guided radiotherapy. Methods: The skin elasticity (R7) data of the head, chest and abdomen were extracted and analyzed its correlation with age by systematic literature review. Fifty-four patients diagnosed with nasopharyngeal carcinoma, breast cancer and cervical cancer were recruited in this study. Firstly, the patients were positioned based on the room laser and markers. Subsequently, the patient position was verified by the Varian On-Board Imager, and then C-Rad Catalyst was adopted to obtain surface images in two states (mask or non-mask) as reference images. In the subsequent fraction treatment, after initial positioning, the local calibration was performed by Catalyst, and setup errors in three directions were recorded. Meanwhile, the patient setup was verified by CBCT twice a week. The Pearson correlation analysis was performed to analyze the correlation between setup error and age. Results: The skin elasticity was negatively correlated with aging (P<0.01). The correlation coefficient between random error and age in head-and-neck cancer were 0.645, 0.624 and 0.866 in the AP, SI and LR directions (all P<0.05) for male patients without mask, respectively. The system error was significantly correlated with age in the LR direction (P<0.05) for male patients, and in the AP direction (P<0.05) for female patients with head-and-neck cancer without mask. The setup error had a significant correlation with skin elasticity in male patients with head-and-neck cancer, and the sequence of absolute value of correlation coefficient was LR>SI>AP. Conclusion In optical surface-guided radiotherapy of head and neck cancer, skin elasticity may be a significant index for assessing the setup errors in male patients.

Objective To analyze the distribution and antimicrobial resistance profile of clinical bacterial strains isolated from blood culture in China.Methods Clinical bacterial strains isolated from blood culture from participating hospitals of Blood Bacterial Resistance Investigation Collaborative System (BRICS) during January 2014 to December 2015 were collected.Antibiotic susceptibility tests were conducted with agar dilution or broth dilution methods as recommended by US Clinical and Laboratory Standards Institute(CLSI)2018.The data were analyzed with Whonet 5.6 software.Results During the study period,4 801 clinical bacterial isolates were collected from 26 hospitals,of which 1 798 (37.5％) were Gram-positive bacteria and 3 003 (62.5％) were gram-negative bacteria.The top 10 isolates were Escherichia coli (33.8％),coagulase-negative Staphylococcus (19.0％),Klebsiella pneumoniae (11.9％),Staphylococcus aureus (10.1％),Acinetobacter baumannii (4.0％),Pseudomonas aeruginosa (3.8％),Streptococcus (3.0％),Enterobacter sulcus (2.9％),Enterococcus faecium (2.8％) and Enterococcus faecalis (1.8％).Methicillin-resistant Staphylococcus aureus (MRSA) and methicillinresistant coagulase-negative Staphylococcus (MRCNS) accounted for 33.9％ (165/487) and 56.9％ (520/913) of Staphylococcus aureus and coagulase-negative Staphylococcus respectively.No vancomycinresistant Staphylococcus was detected.The resistance rate of Enterococcus faecium to vancomycin was 0.7％ (1/135),and no vancomycin-resistant Enterococcus faecaliss was detected.The positive rates of extendedspectrum β-1actamases(ESBLs)-producing Escherichia coli,Klebsiella pneumoniae and Proteus were 56.9％ (923/1 621),30.1％ (172/572) and 29.2％ (7/24),respectively.The positive rates of carbapenemresistant Escherichia coli,Klebsiella pneumoniae,Enterobacter,Salmonella and Citrobacter were 1.2％ (20/1 621),7.2％ (41/572),4.3％ (6/141),1.5％ (1/67) and 2.9％ (1/34),respectively.The resistance rates of Acinetobacter baumannii to polymyxin and tegacycline were 2.6％ (5/190) and 8.9％ (17/190)respectively,and that of Pseudomonas aeruginosa to polymyxin and fosfomycin were 1.1％ (2/183)and 0.6％ (1/183),respectively.Conclusions The surveillance results from 2014 to 2015 show that the main pathogens of blood stream infection in China are Gram-negative bacteria,while Escherichia coli is the most common pathogen,the detection rate of MRSA is lower than other surveillance data in the same period in China;carbapenem-resistant Klebsiella pneumoniae and Escherichia coli are at a low level as shown in this surveillance.

Objective:To investigate the distribution and antimicrobial resistance profile of clinical bacteria isolated from blood culture in China.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2018 to December 2019. Antibiotic susceptibility tests were conducted with agar dilution or broth dilution methods recommended by US Clinical and Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 14 778 bacterial strains were collected from 50 hospitals, of which 4 117 (27.9%) were Gram-positive bacteria and 10 661(72.1%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.2%), Klebsiella pneumoniae (17.0%), Staphylococcus aureus (9.7%), coagulase-negative Staphylococci (8.7%), Pseudomonas aeruginosa (3.7%), Enterococcus faecium (3.4%), Acinetobacter baumannii(3.4%), Enterobacter cloacae (2.9%), Streptococci(2.8%) and Enterococcus faecalis (2.3%). The the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus were 27.4% (394/1 438) and 70.4% (905/1 285), respectively. No glycopeptide-resistant Staphylococcus was detected. More than 95% of S. aureus were sensitive to amikacin, rifampicin and SMZco. The resistance rate of E. faecium to vancomycin was 0.4% (2/504), and no vancomycin-resistant E. faecalis was detected. The ESBLs-producing rates in no carbapenem-resistance E. coli, carbapenem sensitive K. pneumoniae and Proteus were 50.4% (2 731/5 415), 24.6% (493/2001) and 35.2% (31/88), respectively. The prevalence of carbapenem-resistance in E. coli and K. pneumoniae were 1.5% (85/5 500), 20.6% (518/2 519), respectively. 8.3% (27/325) of carbapenem-resistance K. pneumoniae was resistant to ceftazidime/avibactam combination. The resistance rates of A. baumannii to polymyxin and tigecycline were 2.8% (14/501) and 3.4% (17/501) respectively, and that of P. aeruginosa to carbapenem were 18.9% (103/546). Conclusions:The surveillance results from 2018 to 2019 showed that the main pathogens of bloodstream infection in China were gram-negative bacteria, while E. coli was the most common pathogen, and ESBLs-producing strains were in majority; the MRSA incidence is getting lower in China; carbapenem-resistant E. coli keeps at a low level, while carbapenem-resistant K. pneumoniae is on the rise obviously.

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:To investigate the distribution and antimicrobial resistance profile of clinical bacteria isolated from blood culture in China.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2016 to December 2017. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by US Clinical and Laboratory Standards Institute (CLSI) 2019. WHONET 5.6 was used to analyze data.Results:During the study period, 8 154 bacterial strains were collected from 33 hospitals, of which 2 325 (28.5%) were Gram-positive bacteria and 5 829 (71.5%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (34.7%), Klebsiella pneumoniae (15.8%), Staphylococcus aureus (11.3%), coagulase-negative Staphylococci (7.4%), Acinetobacter baumannii (4.6%), Pseudomonas aeruginosa (3.9%), Enterococcus faecium (3.8%), Streptococci (2.9%), Enterobacter cloacae (2.7%) and Enterococcus faecalis (2.5%). Methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MRCNS) accounted for 34.2%(315/922) and 77.7%(470/605), respectively. No vancomycin-resistant Staphylococcus was detected. The resistance rate of Enterococcus faecium to vancomycin was 0.6%(2/312), and no vancomycin-resistant Enterococcus faecium was detected. The ESBLs-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus were 55.7%(1 576/2 831), 29.9%(386/1 289) and 38.5%(15/39), respectively. The incidences of carbapenem-resistance in Escherichia coli, Klebsiella pneumoniae were 1.2%(33/2 831), 17.5%(226/1 289), respectively. The resistance rates of Acinetobacter baumannii to polymyxin and tigecycline were 14.8%(55/372) and 5.9%(22/372) respectively, and those of Pseudomonas aeruginosa to polymyxin and carbapenem were 1.3%(4/315) and 18.7%(59/315), respectively. Conclusion:The surveillance results from 2016 to 2017 showed that the main pathogens of blood stream infection in China were gram-negative bacteria, while Escherichia coli was the most common pathogen; the MRSA incidence was lower than other surveillance data in the same period in China; carbapenem-resistant Escherichia coli was at a low level during this surveillance, while carbapenem-resistant Klebsiella pneumoniae is on the rise.

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.

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.