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 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 investigate the clinical value of Rotarex ? S in debulking the femoropopliteal calcified lesion. Methods:The data of 5 patients with femoropopliteal calcified lesions treated with Rotarex ? S combined with drug balloon treatment admitted to the First Affiliated Hospital of Dalian Medical University from March 2020 to December 2021 were retrospectively analyzed. The success rate and complications of all operations were recorded. CT software was used to compare the effective lumen area of the target lesion area before and after surgery in all cases, and the ischemic grade of the affected limb before and after surgery was recorded in all patients. Results:All 5 femoropopliteal calcified lesions were successfully treated with Rotarex ? S debulking followed with drug-coated balloon angioplasty without flow-limited dissections, vascular perforation and distal embolizations, with a success rate of 100%. The effective lumen area for calcified lesions were increased 9-15.11 mm 2 (median: 13 mm 2). The Rutherford classifications were improved from R 2-4 to R 1-2. Conclusions:Femoropopliteal calcified lesion debulking with Rotarex ? S was safe and effective.

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.

OBJECTIVETo develop a real-time PCR assay for the rapid identification of Clostridium(C.)difficile and its toxin.

METHODSTaqMan real-time PCR was developed for the rapid identification of species specific gene(tpi) of C. difficile strains and the toxins A(TcdA), B(TcdB) and truncated toxin A(TcdAT). Sensitivity, specificity and anti-interference ability of these methods were estimated, as well. Feces sampled from fifty diarrhea patients were tested by real-time PCR and compared to the results from VIDAS assay.

RESULTSThe detection limits of tpi were 6×10⁻² CFU/µl and 6 × 10⁻¹ CFU/µl in the non-oxin producing and toxin producing strains, respectively. The coefficients of variability(CV) of intra-assay and inter-assay for the detection limits of tpi in the non-toxin producing strain were 2.1% and 2.3% . The CVs of intra-assay and inter-assay for the detection limit of tpi, tcdA, tcdB and tcdAT in the toxin producing strain were 3.0% and 3.4%, 2.9% and 3.2%, 5.3% and 5.7%, 2.7% and 2.8%, respectively. No interference was detected from other genus or species in clostridium. From 50 clinical samples, thirty-nine of them were negative and six of them were positive under the TaqMan-MGB probe technique in accordance with VIDAS. Five samples appeared positive using the TaqMan-MGB probe technique, in which 3 were dubious and 2 were negative under VIDAS.

CONCLUSIONThe newly developed method was a sensitive and reliable assay for rapid identification of C. difficile and its toxin. This method could be used to screen C. difficile isolates harboring truncated toxin A to avoid misdiagnosis, clinically.

Bacterial Proteins ; isolation & purification ; Bacterial Toxins ; isolation & purification ; Clostridium difficile ; isolation & purification ; Enterotoxins ; isolation & purification ; Real-Time Polymerase Chain Reaction ; methods

BACKGROUNDA number of studies have demonstrated the rates of overall and aneurysm-related mortality and morbidity in Western populations. The cardiovascular risk factors influencing postoperative outcome have been also reported. Until recently, little has been known about the prognosis in this patient cohort in the Chinese population. We evaluated the independent predictors of mortality and morbidity in abdominal aortic aneurysm (AAA) patients undergoing elective surgical treatment and emphasized whether the coronary artery revascularization could have any effect on the overall mortality and morbidity in patients following the current guideline recommendation.

METHODSA total of 386 patients (174 women) undergoing surgery in Beijing Anzhen Hospital from January 2008 to June 2010 were enrolled (mean age (70.6±10.5) years). Kaplan-Meier curves were constructed to compare the mortality and morbidity of AAA patients with coronary artery revascularization and those without. A Cox proportional hazards model was constructed to identify clinical factors associated with two-year outcomes. The primary outcomes were death from any cause, the pre-specified morbidity was re-hospitalization for pulmonary conditions, congestive heart failure, angina, ischemic/hemorrhagic stroke.

RESULTSDuring the two-year follow-up, 34 patients died and 65 experienced re-hospitalization with pulmonary conditions, congestive heart failure, angina, or ischemic/hemorrhagic stroke. Kaplan-Meier survival analysis showed that the AAA patients with cardiac revascularization had no higher incidence of overall mortality and major morbidity than those without (log-rank test P = 0.35 and P = 0.40, respectively). Cox proportional hazards regression analysis showed that level of lowdensity lipoprotein (HR, 4.06; 95% CI: 1.19-18.7, P = 0.027) and AAA size (HR, 2.18; 95% CI: 1.28-11.65, P = 0.036) were independently associated with the incidence of overall mortality. Long-term use of angiotensin converting enzyme inhibitors, statins, AAA size and systolic blood pressure were independent predictors of the secondary pre-specified outcomes.

CONCLUSIONSCoronary artery revascularization following the guideline recommendations did not increase the mortality and morbidity of Chinese with AAA who were undergoing repair. Absence of angiotensin converting enzyme inhibitors and statins, AAA size, and systolic blood pressure were powerful predictors of the clinical events.

Adult ; Aged ; Aged, 80 and over ; Aortic Aneurysm, Abdominal ; surgery ; Coronary Artery Bypass ; adverse effects ; Coronary Artery Disease ; surgery ; Female ; Humans ; Male ; Middle Aged ; Young Adult

Objective To develop a real-time PCR assay for the rapid identification of Clostridium(C.)difficile and its toxin. Methods TaqMan real-time PCR was developed for the rapid identification of species specific gene(tpi)of C. difficile strains and the toxins A(TcdA),B(TcdB) and truncated toxin A(TcdAT). Sensitivity,specificity and anti-interference ability of these methods were estimated,as well. Feces sampled from fifty diarrhea patients were tested by real-time PCR and compared to the results from VIDAS assay. Results The detection limits of tpi were 6×10-2 CFU/μl and 6 × 10-1 CFU/μl in the non-oxin producing and toxin producing strains,respectively. The coefficients of variability (CV) of intra-assay and inter-assay for the detection limits of tpi in the non-toxin producing strain were 2.1% and 2.3%. The CVs of intra-assay and inter-assay for the detection limit of tpi,tcdA,tcdB and tcdAT in the toxin producing strain were 3.0%and 3.4%,2.9%and 3.2%,5.3%and 5.7%,2.7%and 2.8%,respectively. No interferance was detected from other genus or species in clostridium. From 50 clinical samples,thirty-nine of them were negative and six of them were positive under the TaqMan-MGB probe technique in accordance with VIDAS. Five samples appeared positive using the TaqMan-MGB probe technique,in which 3 were dubious and 2 were negative under VIDAS. Conclusion The newly developed method was a sensitive and reliable assay for rapid identification of C. difficile and its toxin. This method could be used to screen C. difficile isolates harboring truncated toxin A to avoid misdiagnosis,clinically.

Objective: To investigate changes of plasma glucagon level in patients with heart failure (HF) caused by coronary heart disease (CHD) and its clinical significance. Methods: A total of 30 HF patients caused by CHD were selected as HF group, another 30 healthy subjects with corresponding age and gender were regard as normal control group. HF patients received comprehensive therapy of enhancing myocardial contractility, diuretic and vasodilator of 7~10d according to Chinese diagnostic and treatment guideline of chronic heart failure. Changes of glucagon level before and after treatment were observed. Results: Before treatment, plasma level of glucagon in HF group was significantly higher than that of normal control group [(205.67±120.22) ng/L vs. (90.53±20.5) ng/L, P<0.05]. After treatment, plasma level of glucagon [(120.42±30.33) ng/L] significantly decreased than before treatment (P<0.05) in HF group. Conclusion: Plasma glucagon significantly increases in patients with heart failure and gradually decreases to near normal level after treatment. Glucagon level may be regard as one of indexes judging patients’ condition.

Objective To evaluate the accuracy of multi-slice CT(MSCT) angiography in detection of carotid artery stenosis. Methods A total of 29 consecutive patients with known or suspected carotid artery disease were studied by MSCT. The results were compared with quantitative carotid angiography.Results In the 203 carotid arteries of 29 patients, 22 of 24 carotid arteries with significant stenosis ( ≥ 30% reduction of vessel diameter) were correctly detected by MSCT,and 171 of 179 carotid arteries with normal or mild stenosis ( ＜ 30% reduction of vessel diameter) were correctly detected by MS CT. These values corresponded to sensitivity of 91.7% (22/24), specificity of 95.5% (171/179), positivè predictive value of 73.3% (22/30), and negative predictive value of 98.8% ( 171/173 ) for the detection of significant carotid artery stenosis by MSCT. In the 203 carotid arteries of 29 patients, 14 of 14 carotid arteries with high-grade stenosis were correctly detected by MSCT,and 186 of 189 carotid arteries with normal or mild stenosis were correctly detected by MSCT. These values corresponded to sensitivity of 100.0%(14/14), specificity of 98.4% (186/189), positive predictive value of 82.4% (14/17),and negative predictive value of 100.0%(186/186) for the detection of high-grade carotid arteries stenosis by MSCT. Conclusions MSCT angiography shows significant carotid artery stenosis with high accuracy. It may be used as an alternative for carotid angiography in detection of carotid artery stenosis.