1.Exploration of Rat Fetal Lung Tissue Fixation Methods
Liyu LIU ; Bo JI ; Xiaoxuan LIU ; Yang FANG ; Ling ZHANG ; Tingting GUO ; Ye QUAN ; Hewen LI ; Yitian LIU
Laboratory Animal and Comparative Medicine 2025;45(4):432-438
ObjectiveThis study explores the methods of lung tissue extraction and fixation required for pathological studies of fetal rats, based on the unique physiological structure of fetal rat lung tissue and existing lung tissue fixation techniques for adult rats. MethodsSix pregnant adult SD rats at 20.5 days of gestation were subjected to cesarean section to obtain fetal rats. Four healthy fetal rats with similar body weight, vital signs, and respiratory status were selected from each pregnant rat, and they were randomly divided into the following groups using a random number table: direct lung infiltration group, lung infiltration group after intratracheal infusion, whole-body infiltration group of fetal rats, and whole-body infiltration group after intratracheal infusion of fetal rats. To systematically compare and analyze the anatomical morphology under different fixation methods, lung tissues from four groups of fetal rats were harvested, perfused, and fixed, and the gross morphology of lung tissues in each group was observed. Paraffin sections were prepared and stained with Hematoxylin-Eosin (H&E). The histological morphology of the whole lung, alveoli, and bronchi was further examined under optical microscopy. ResultsIn the direct lung infiltration group, the hilar structures were unclear, lung lobation was indistinct, the shape was irregular, lung cavities were small, and alveoli and bronchi were shrunken. In the lung infiltration group after intratracheal infusion, the hilar structures were clear, lobation was pronounced, the shape was regular, lung cavities were large, and alveoli and bronchi were full. Both the whole-body infiltration group and whole-body infiltration group after intratracheal infusion of fetal rats exhibited visible lungs, hearts, skins, and other organs. The lung tissues of both groups showed obvious lobulation, irregular shape, and damage at the margins of lung lobes. In the whole-body infiltration group, the thoracic cavities of the fetus were flattened, lung cavities were small, and alveoli and bronchi were shrunken. In the whole-body infiltration group after intratracheal infusion of fetal rats, the fetal thoracic cavities were full, lung cavities were large, and alveoli and bronchi were relatively full. ConclusionThe lung infiltration after intratracheal infusion method for fetal rat lung tissue fixation outperforms direct lung infiltration, whole-body infiltration of fetal rats, and whole-body infiltration after intratracheal infusion of fetal rats in terms of preservation of the lung tissue's original morphology, paraffin sectioning, staining, and pathological observation and analysis. The embedding, sectioning, and staining processes are also simple and save consumables. Therefore, intratracheal infusion followed by lung infiltration method is recommended for fixation in histopathological observation of fetal rat lung tissue.
2.Monotropein Induced Apoptosis and Suppressed Cell Cycle Progression in Colorectal Cancer Cells.
Quan GAO ; Lin LI ; Qi-Man ZHANG ; Qin-Song SHENG ; Ji-Liang ZHANG ; Li-Jun JIN ; Rui-Yan SHANG
Chinese journal of integrative medicine 2024;30(1):25-33
OBJECTIVE:
To determine whether monotropein has an anticancer effect and explore its potential mechanisms against colorectal cancer (CRC) through network pharmacology and molecular docking combined with experimental verification.
METHODS:
Network pharmacology and molecular docking were used to predict potential targets of monotropein against CRC. Cell counting kit assay, plate monoclonal assay and microscopic observation were used to investigate the antiproliferative effects of monotropein on CRC cells HCT116, HT29 and LoVo. Flow cytometry and scratch assay were used to analyze apoptosis and cell cycle, as well as cell migration, respectively in HCT116, HT29, and LoVo cells. Western blotting was used to detect the expression of proteins related to apoptosis, cell cycle, and cell migration, and the expression of proteins key to the Akt pathway.
RESULTS:
The Gene Ontology and Reactome enrichment analyses indicated that the anticancer potential of monotropein against CRC might be involved in multiple cancer-related signaling pathways. Among these pathways, RAC-beta serine/threonine-protein kinase (Akt1, Akt2), cyclin-dependent kinase 6 (CDK6), matrix metalloproteinase-9 (MMP9), epidermal growth factor receptor (EGFR), cell division control protein 42 homolog (CDC42) were shown as the potential anticancer targets of monotropein against CRC. Molecular docking suggested that monotropein may interact with the 6 targets (Akt1, Akt2, CDK6, MMP9, EGFR, CDC42). Subsequently, cell activity of HCT116, HT29 and LoVo cell lines were significantly suppressed by monotropein (P<0.05). Furthermore, our research revealed that monotropein induced cell apoptosis by inhibiting Bcl-2 and increasing Bax, induced G1-S cycle arrest in colorectal cancer by decreasing the expressions of CyclinD1, CDK4 and CDK6, inhibited cell migration by suppressing the expressions of CDC42 and MMP9 (P<0.05), and might play an anticancer role through Akt signaling pathway.
CONCLUSION
Monotropein exerts its antitumor effects primarily by arresting the cell cycle, causing cell apoptosis, and inhibiting cell migration. This indicates a high potential for developing novel medication for treating CRC.
Humans
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Cell Proliferation
;
Matrix Metalloproteinase 9
;
Molecular Docking Simulation
;
Cell Cycle
;
ErbB Receptors
;
Apoptosis
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Colorectal Neoplasms/pathology*
;
Cell Line, Tumor
3.Mannitol inhibits the proliferation of neural stem cell by a p38 mitogen-activated protein kinase-dependent signaling pathway
Hai-Zhen DUAN ; Xin ZHOU ; Quan HU ; Meng-Long LIU ; Shu-Hong WANG ; Ji ZHANG ; Xu-Heng JIANG ; Tian-Xi ZHANG ; An-Yong YU
Chinese Journal of Traumatology 2024;27(1):42-52
Purpose::Mannitol is one of the first-line drugs for reducing cerebral edema through increasing the extracellular osmotic pressure. However, long-term administration of mannitol in the treatment of cerebral edema triggers damage to neurons and astrocytes. Given that neural stem cell (NSC) is a subpopulation of main regenerative cells in the central nervous system after injury, the effect of mannitol on NSC is still elusive. The present study aims to elucidate the role of mannitol in NSC proliferation.Methods::C57 mice were derived from the animal house of Zunyi Medical University. A total of 15 pregnant mice were employed for the purpose of isolating NSCs in this investigation. Initially, mouse primary NSCs were isolated from the embryonic cortex of mice and subsequently identified through immunofluorescence staining. In order to investigate the impact of mannitol on NSC proliferation, both cell counting kit-8 assays and neurospheres formation assays were conducted. The in vitro effects of mannitol were examined at various doses and time points. In order to elucidate the role of Aquaporin 4 (AQP4) in the suppressive effect of mannitol on NSC proliferation, various assays including reverse transcription polymerase chain reaction, western blotting, and immunocytochemistry were conducted on control and mannitol-treated groups. Additionally, the phosphorylated p38 (p-p38) was examined to explore the potential mechanism underlying the inhibitory effect of mannitol on NSC proliferation. Finally, to further confirm the involvement of the p38 mitogen-activated protein kinase-dependent (MAPK) signaling pathway in the observed inhibition of NSC proliferation by mannitol, SB203580 was employed. All data were analyzed using SPSS 20.0 software (SPSS, Inc., Chicago, IL). The statistical analysis among multiple comparisons was performed using one-way analysis of variance (ANOVA), followed by Turkey's post hoc test in case of the data following a normal distribution using a Shapiro-Wilk normality test. Comparisons between 2 groups were determined using Student's t-test, if the data exhibited a normal distribution using a Shapiro-Wilk normality test. Meanwhile, data were shown as median and interquartile range and analyzed using the Mann-Whitney U test, if the data failed the normality test. A p < 0.05 was considered as significant difference. Results::Primary NSC were isolated from the mice, and the characteristics were identified using immunostaining analysis. Thereafter, the results indicated that mannitol held the capability of inhibiting NSC proliferation in a dose-dependent and time-dependent manner using cell counting kit-8, neurospheres formation, and immunostaining of Nestin and Ki67 assays. During the process of mannitol suppressing NSC proliferation, the expression of AQP4 mRNA and protein was downregulated, while the gene expression of p-p38 was elevated by reverse transcription polymerase chain reaction, immunostaining, and western blotting assays. Subsequently, the administration of SB203580, one of the p38 MAPK signaling pathway inhibitors, partially abrogated this inhibitory effect resulting from mannitol, supporting the fact that the p38 MAPK signaling pathway participated in curbing NSC proliferation induced by mannitol.Conclusions::Mannitol inhibits NSC proliferation through downregulating AQP4, while upregulating the expression of p-p38 MAPK.
4.National bloodstream infection bacterial resistance surveillance report (2022) : Gram-negative bacteria
Zhiying LIU ; Yunbo CHEN ; Jinru JI ; Chaoqun YING ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(1):42-57
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.
5.Establishment of HPLC characteristic chromatogram and quantitative transmission laws for Baqi Rougan Decoction reference sample
Sai-Long GENG ; Qin ZHOU ; Shui-Gen SUN ; Man LI ; Li-Jie ZHAO ; Ji-Quan ZHANG ; Yi FENG
Chinese Traditional Patent Medicine 2024;46(2):370-378
AIM To establish the HPLC characteristic chromatogram of Baqi Rougan Decoction reference sample,and to investigate its quantitative transmission laws.METHODS The contents of calycosin 7-O-glucoside,hesperidin,rosmarinic acid,curcumenol and nystose were determined.The transfer rates of decoction piece-aqueous decoction-reference sample were calculated,after which the paste-forming rate and pH value were recorded.RESULTS There were sixteen characteristic peaks in fifteen batches of reference samples with the similarities of 0.90,nine of which were identified.The average transfer rates of nystose and calycosin 7-O-glucoside in the reference sample were(83.14±6.25)%and(77.81±8.31)%,while those of rosmarinic acid and curcumenol in the aqueous decoction-reference sample were(81.71±6.27)%and(72.16±5.91)%,along with the average paste-forming rate and pH value of(38.91%±1.46%)and 5.13±0.08,respectively.CONCLUSION This stable and feasible method can provide a reference for the selection of preparation process and evaluation of key chemical properties for Baqi Rougan Decoction.
6.Bioequivalence study of entecavir tablets in healthy Chinese subjects under fasting condition
Juan ZHANG ; Meng WANG ; Ming HUANG ; Ji WANG ; Quan-Ying ZHANG
The Chinese Journal of Clinical Pharmacology 2024;40(9):1311-1315
Objective To evaluate the pharmacokinetics and bioequivalence of two entecavir tablets under fasting condition in Chinese healthy volunteers.Methods A single oral dose of 0.50 mg entecavir test and reference formulations was given to 30 healthy volunteers in the fasting state according to two randomized open-label crossover clinical studies.Plasma concentrations were determined by HPLC-MS/MS after deproteinized with acetonitrile.The pharmacokinetic parameters were calculated by WinNonlin 6.4.The bioequivalence of entecavir tablets test and its reference in the fasting state were evaluated respectively.Results In the fasting state,the main pharmacokinetic parameters of entecavir were as follows:Cmax were(4 390.00±1 257.56)and(4 421.00±1 239.55)pg·mL-1;tmax were 0.67(0.33,2.00)and 0.75(0.50,2.00)h;t1/2were(29.71±14.50)and(35.43±16.58)h,AUC0_72h were(12 252.43±2 671.28)and(12 063.43±2 151.50)pg·mL-1·h.The 90%confidence intervals of the mean ratio of Cmax,AUC0-72h and AUC0-∞ of the text and reference formulations were all within the equivalent interval of 80.00%-125.00%.Conclusion The entecavir tablets test and its reference were bioequivalent in the fasting state.
7.Research status of traditional Chinese medicine monomer,drug-to-drug groups and compound formula in the treatment of endometriosis
Bin YUE ; Yuan-Huan CHEN ; Quan-Sheng WU ; Xiao-Hua ZHANG ; Yuan CHENG ; Hao MEI ; Can-Can HUANG ; Zuo-Liang ZHANG ; Xiu-Jia JI
The Chinese Journal of Clinical Pharmacology 2024;40(15):2283-2287
Interventions for endometriosis(EMs)include surgical excision of lesions and hormonal therapy,which usually have limited efficacy and adverse drug reactions.Traditional Chinese medicine(TCM)has the multi-component and multi-target characteristics,which can help patients achieve good clinical benefits by intervening in different parts of the disease.In this paper,we briefly discuss the modern pharmacology of Sanlang and Curcuma longa,and deeply summarize the possible mechanisms of action of TCM monomer and classical compound extracts and their active ingredients through signal pathways in inflammation,immune system,angiogenesis,hormone regulation,etc.,so as to provide theoretical bases for the clinical use of TCM monomers,drug-to-drug groups and compounds in the treatment of EMs.
8.Integrated Detection Techniques for Forensic DNA and DNA Methylation Markers
Na YI ; Guang-Bin ZHAO ; Ke-Lai KANG ; Yi-Ren YAO ; Ke-Li GUO ; Jie ZHAO ; Chi ZHANG ; Lei MIAO ; Le WANG ; An-Quan JI
Progress in Biochemistry and Biophysics 2024;51(9):2156-2167
DNA genetic markers have always played important roles in individual identification, kinship analysis, ancestry inference and phenotype characterization in the field of forensic medicine. DNA methylation has unique advantages in biological age inference, body fluid identification and prediction of phenotypes. The majority of current studies independently examine DNA and DNA methylation markers using various workflows, and they use various analytical procedures to interpret the biological information these two markers present. Integrated methods detect DNA and DNA methylation markers simultaneously through a single experimental workflow using the same preparation of sample. Therefore, they can effectively reduce consumption of time and cost, streamline experimental procedures, and preserve valuable DNA samples taken from crime scenes. In this paper, the integrated detection approaches of DNA and DNA methylation markers on different detection platforms were reviewed. In order to convert methylation modifications to detectable forms, several options were available for pretreatment of genomic DNA, including digestion with methylation-sensitive restriction enzyme, affinity enrichment of methylated fragments, conversion of methylated or unmethylated cytosine. Multiplexed primers can be designed for DNA markers and converted DNA methylation markers for co-amplification. The schemes of using capillary electrophoresis platform for integrated detection add the pretreatment of genomic DNA on the basis of detecting DNA genetic markers. DNA and DNA methylation markers are then integrated by co-amplification. But the limited number of fluorescent options available and the length of amplicons restrict the type and quantity of markers that can be integrated into a panel. Pyrophosphate sequencing also supports integrated detection of DNA and DNA methylation markers. On this platform, due to the conversion of unmethylated cytosine to thymine after treatment with bisulfite, the methylation level of CpG site can be directly calculated using the peak height ratio of cytosine bases and thymine bases. Therefore, the methylation levels and SNP typing can be simultaneously obtained. However, due to the limited read length of sequencing, the detection of markers with longer amplicons is restricted. It is not conducive to fully interpret the complete information of the target sequence. Next-generation sequencing also supports integrated detection of DNA and DNA methylation markers. A preliminary experimental process including DNA extraction, pretreatment of genomic DNA, co-preparation of DNA and DNA methylation library and co-sequencing, has been formed based on the next-generation sequencing platform. It confirmed the feasibility of next-generation sequencing technology for integrated detection of DNA and DNA methylation markers. In field of biomedicine, various integrated detection schemes and corresponding data analysis approaches of DNA and DNA genetic markers developed based on the above detection process.Co-analysis can simultaneously obtain the genomic genetic and epigenetic information through a single analytic process. These schemes suggest that next-generation sequencing may be an effective method for achieving more accurate and highly integrated detection, helping to explore the potential for application in forensic biological samples. We finally explore the impact of interactions between sites and different pretreatment methods on the integrated detection of DNA and DNA methylation markers, and also propose the challenge of applying third-generation sequencing for integrated detection in forensic samples.
9.A Multicenter, Randomized, Double-blind, and Placebo-parallel Controlled Trial of Tibetan Medicine Ruyi Zhenbaowan in Treatment of Knee Osteoarthritis
Chunquan SUN ; Yanming XIE ; Jinghua GAO ; Weiheng CHEN ; Lianxin WANG ; Shangquan WANG ; Xiangdong TIAN ; Zujian XU ; Yuxin ZHENG ; Mingwang ZHOU ; Chungen LI ; Zhanwang XU ; Jiayi GUO ; Shuangqing DU ; Qigang CHEN ; Quan JI ; Zhiqiang BAI ; Jing XIAO ; Wanli QI ; Weiyi YANG ; Jingxiao ZHANG
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(24):57-67
ObjectiveThis study aimed to evaluate the clinical efficacy of Ruyi Zhenbaowan(RYZBW)in the treatment of initial and early knee osteoarthritis (KOA) through a prospective multicenter,randomized,double-blind,and placebo-parallel controlled trial. MethodFrom October 13th, 2021 to December 25th, 2021, 240 KOA subjects meeting the acceptance criteria were enrolled in 15 sub-centers including Wangjing Hospital, Chinese Academy of Chinese Medical Sciences, and they were randomly divided into observation group and control group, with 120 cases in each group. The intervention measures for the observation group were RYZBW + health education, and the intervention measures for the control group were RYZBW placebo + health education. The intervention period in both groups was four weeks, and they were followed up for four weeks after the intervention. The primary outcome measure was the total score of Western Ontario and McMaster University Osteoarthritis Index score (WOMAC score), and the secondary outcome measures were the response rate of visual scale (VAS) pain score, WOMAC sub item scores (joint pain, joint stiffness, and joint function), quality of life (SF-12) score, and traditional Chinese medicine (TCM) syndrome score. Result(1) Efficacy evaluation. The marginal model results showed that the observation group was better than the control group in improving the WOMAC total score and WOMAC pain score in the treatment of KOA with RYZBW, and the difference was statistically significant (P<0.05). There was no significant difference between the two groups in improving VAS score response rate, WOMAC function score, WOMAC stiffness score, SF12-PCS (quality of life-physical health) score, SF12-MCS (quality of life-mental health) score, and TCM syndrome score. (2) Subgroup analysis. ① In terms of VAS score response rate, the response rate of the observation group was higher than that of the control group for subjects with baseline VAS score of (4, 5], and the difference was statistically significant (P<0.05). ② In terms of TCM syndrome score, for subjects aged [56, 60] and [61, 65], the decrease in total TCM syndrome score in the observation group was better than that in the control group, and the difference was statistically significant (P<0.05). ConclusionTibetan medicine RYZBW has good clinical efficacy in improving WOMAC total score, VAS score response rate, WOMAC pain score, WOMAC function score, and TCM syndrome score for patients with initial and early KOA, which can fill the lack of Tibetan medicine RYZBW in the treatment of KOA and make a demonstration study for the inheritance and development of ethnic medicine.
10.National bloodstream infection bacterial resistance surveillance report(2022): Gram-positive bacteria
Chaoqun YING ; Yunbo CHEN ; Jinru JI ; Zhiying LIU ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(2):99-112
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.

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