1.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe2+), whereas clMagR favors ferric iron (Fe3+) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe2+-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe2+/Fe3+ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
2.Protective effect of the active component DMDD from Averrhoa carambola root on myocardial injury in diabetic mice and its correlation with the NCOA4/FTH1/ATG8 axis
Yongxin CHEN ; Yuxuan LI ; Kailei GU ; Jiajun YOU ; Xiaohan SUN ; Jing MA ; Yanping ZHOU ; Xiaojie WEI
China Pharmacy 2026;37(9):1141-1147
OBJECTIVE To investigate the protective effect of 2-dodecyl-6-methoxy-2,5-diene-1,4-cyclohexanedione (DMDD), an active component from Averrhoa carambola root, on myocardial injury in diabetic mice based on the nuclear receptor coactivator 4/ferritin heavy chain 1/autophagy-related protein 8 (NCOA4/FTH1/ATG8) axis. METHODS The successfully modeled diabetic mice were randomly divided into model group and DMDD low-, medium-, and high-dose (12.5, 25, 50 mg/kg) groups, while an additional non-modeled control group was established, with 6 mice in each group. Each group received the corresponding drug solution or an equal volume of normal saline intragastically once daily for 21 consecutive days. After the administration, the levels of fasting blood glucose (FBG), serum lactate dehydrogenase (LDH), and creatine kinase isoenzyme MB (CK-MB) were measured. Myocardial pathological changes, degree of fibrosis, and myocardial cell ultrastructure were observed. Myocardial cell death index and NCOA4 protein positive index were detected. The protein expression levels of NCOA4, FTH1, ATG8, solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4) in cardiac tissue were measured. RESULTS Compared with model group, each DMDD group showed significant alleviation of cardiac pathological injury and varying degrees of improvement in the myocardial cell ultrastructure. The FBG and serum LDH and CK-MB levels, the myocardial cell death index and NCOA4 protein positive index,the protein expression levels of NCOA4, FTH1, and ATG8 in cardiac tissue were significantly decreased ( P <0.001), while the protein expression levels of SLC7A11 and GPX4 were significantly increased ( P <0.001). CONCLUSIONS DMDD can reduce blood glucose levels, alleviate myocardial histopathological injury, and inhibit cell death in diabetic mice. The mechanism is associated with inhibiting excessive activation of the NCOA4/FTH1/ATG8 axis and reducing ferritinophagy.
3.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe2+), whereas clMagR favors ferric iron (Fe3+) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe2+-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe2+/Fe3+ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.
4.Three-dimensional automated right ventricular quantification for predicting right ventricular function dysfunction in patients with severe aortic stenosis
Wei CAO ; Wei JING ; Xue YANG ; Fang WANG ; Li ZHOU
Chinese Journal of Interventional Imaging and Therapy 2025;22(8):520-524
Objective To explore the value of three-dimensional automated right ventricular quantification(3D Auto RV)for predicting right ventricular function dysfunction in patients with severe aortic stenosis(AS).Methods Eighty severe AS patients were retrospectively enrolled.Based on right ventricular ejection fraction(RVEF)obtained with 3D Auto RV,the patients were classified into right ventricular compensation group(RVEF≥45%,compensation group,n=56)and right ventricular function decompensation(RVEF<45%,decompensation group,n=24)group.Ultrasonic parameters related to right ventricular structure and function were compared between groups.Univariable analysis and multivariable logistic regression were performed to observe ultrasound parameters related to right ventricular function,so as to screen out the independent predictors of right ventricular functional decompensation(dysfunction)in patients with severe AS.Results Compared with those in compensation group,right ventricular end diastolic volume and right ventricular end systolic volume of decompensation group increased,while right ventricular fractional area change,tricuspid annular plane systolic excursion,right ventricular free wall longitudinal strain(RVFWLS),septal longitudinal strain(SLS),right ventricular stroke volume and RVEF all decreased(all P<0.05).Valvulo-arterial impedance(OR=2.337),left ventricular ejection fraction(OR=0.751)and RVFWLS/pulmonary artery systolic pressure(right ventricle-pulmonary artery coupling)(OR=0.653)were all independent predictors of right ventricular dysfunction in patients with severe AS(all P<0.05).Conclusion 3D Auto RV could be used to effectively predict right ventricular dysfunction in patients with severe AS.
5.Disinfection effect of periodic hypochlorous acid on water supply pipeline and metagenomic next-generation sequencing for water specimens
Hong ZHOU ; Xiaodong GAO ; Meixia WANG ; Mengzhu ZHANG ; Jun YANG ; Jing ZHUANG ; Hua XU ; Wei SUN ; Qingfeng SHI
Chinese Journal of Infection Control 2025;24(9):1244-1249
Objective To explore the disinfection effect of periodic hypochlorous acid infusion on water supply pipelines.Methods Water specimens from 6 water outlets of central sterile supply department were collected at baseline for microbial culture.After introducing a slightly acidic hypochlorous acid water generator,water speci-mens were collected every 10 days.Continuous disinfection with hypochlorous acid was carried out on the 1st-3rd day,and discontinued on the 4th-10th day.Water specimens of 6 water outlets were collected on the 1st,4th,7th,and 10th day of each cycle,in total 3 cycles.Microbial culture and metagenomic next-generation sequencing(mNGS)analysis were conducted simultaneously on all water specimens from the outlets of the endoscope cleaning tank.Results Before disinfection of the pipeline,a total of 18 bottles of water specimens were collected.Bacterial count of water specimens from 10 bottles(55.56%)was between 102 and 104 CFU/mL,mainly Sphingomonas ad-hesins and Bacillus cereus.After disinfection,only 2 out of 72 water specimens(2.78%)exceeded the bacterial lim-it.The mNGS results showed that three most dominant bacterial genera in the pre-disinfection water specimens were Sphingomonas,Methylobacterium,and Ralstonia,with stringent mapped reads number(SMRN)ranging from 10 000 to 100 000;while the most dominant bacterial genera in post-disinfection water specimens were Lacto-baci-llus,Ralstonia,Acinetobacter,and Bradyrhizobium.PCoA analysis showed that there was a statistically sig-nificant difference in β-diversity of water specimens before and after disinfection(P<0.05).Conclusion Periodic hypochlorous acid infusion disinfection can effectively remove bacterial biofilms in water pipelines,but there is a risk of bacterial biofilm recovery during disinfection suspension.In the future,monitoring and management of medical water should be strengthened.
6.Guideline for Adult Weight Management in China
Weiqing WANG ; Qin WAN ; Jianhua MA ; Guang WANG ; Yufan WANG ; Guixia WANG ; Yongquan SHI ; Tingjun YE ; Xiaoguang SHI ; Jian KUANG ; Bo FENG ; Xiuyan FENG ; Guang NING ; Yiming MU ; Hongyu KUANG ; Xiaoping XING ; Chunli PIAO ; Xingbo CHENG ; Zhifeng CHENG ; Yufang BI ; Yan BI ; Wenshan LYU ; Dalong ZHU ; Cuiyan ZHU ; Wei ZHU ; Fei HUA ; Fei XIANG ; Shuang YAN ; Zilin SUN ; Yadong SUN ; Liqin SUN ; Luying SUN ; Li YAN ; Yanbing LI ; Hong LI ; Shu LI ; Ling LI ; Yiming LI ; Chenzhong LI ; Hua YANG ; Jinkui YANG ; Ling YANG ; Ying YANG ; Tao YANG ; Xiao YANG ; Xinhua XIAO ; Dan WU ; Jinsong KUANG ; Lanjie HE ; Wei GU ; Jie SHEN ; Yongfeng SONG ; Qiao ZHANG ; Hong ZHANG ; Yuwei ZHANG ; Junqing ZHANG ; Xianfeng ZHANG ; Miao ZHANG ; Yifei ZHANG ; Yingli LU ; Hong CHEN ; Li CHEN ; Bing CHEN ; Shihong CHEN ; Guiyan CHEN ; Haibing CHEN ; Lei CHEN ; Yanyan CHEN ; Genben CHEN ; Yikun ZHOU ; Xianghai ZHOU ; Qiang ZHOU ; Jiaqiang ZHOU ; Hongting ZHENG ; Zhongyan SHAN ; Jiajun ZHAO ; Dong ZHAO ; Ji HU ; Jiang HU ; Xinguo HOU ; Bimin SHI ; Tianpei HONG ; Mingxia YUAN ; Weibo XIA ; Xuejiang GU ; Yong XU ; Shuguang PANG ; Tianshu GAO ; Zuhua GAO ; Xiaohui GUO ; Hongyi CAO ; Mingfeng CAO ; Xiaopei CAO ; Jing MA ; Bin LU ; Zhen LIANG ; Jun LIANG ; Min LONG ; Yongde PENG ; Jin LU ; Hongyun LU ; Yan LU ; Chunping ZENG ; Binhong WEN ; Xueyong LOU ; Qingbo GUAN ; Lin LIAO ; Xin LIAO ; Ping XIONG ; Yaoming XUE
Chinese Journal of Endocrinology and Metabolism 2025;41(11):891-907
Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.
7.Clinical characteristics and carbapenem resistance gene of Klebsiella pneumonia isolates from children in Chongqing region from 2019 to 2024
Meirong ZHOU ; Dapeng CHEN ; Chunmei JING ; Zhongzheng XIONG ; Yupei XIANG ; Fang LIU ; Wei XIE
Chinese Journal of Preventive Medicine 2025;59(10):1655-1664
Objective:To investigate the clinical distribution characteristics changes in antimicrobial resistance, and carbapenemase resistance genes of Klebsiella pneumoniae isolated from children in Chongqing region during the period of January 2019 to December 2024, providing a basis for the rational use of antibiotics and the prevention and control of nosocomial infections.Methods:An observational study was conducted to retrospectively analyze 5 020 Klebsiella pneumoniae (KP) isolates detected in four hospitals of the Southwest Pediatric Laboratory Specialty Alliance. Antimicrobial susceptibility testing was performed by the minimum inhibitory concentration method combined with the disk diffusion method. Results were interpreted according to the 2024 Clinical and Laboratory Standards Institute (CLSI) standards. Carbapenemase resistance genes were detected by polymerase chain reaction (PCR) combined with Sanger sequencing. WHONET 5.6 was used for resistance analysis and SPSS 19.0 for statistical analysis. The chi-square test was used to assess trends in resistance rates, ESBL detection rates, and resistance rates of different CRKP carbapenemase genotypes from 2019 to 2024. Statistical significance was confirmed if the two-tailed P-value was <0.05. Results:A total of 5 020 strains were isolated, with a detection rate of 5.1% (5 020/99 063). The majority were from sputum (59.2%, 2 970/5 020), followed by pus (17.1%, 857), urine (9.7%, 487), venous blood (6.5%, 326), secretions (2.6%, 130), and other specimens (5.0%, 250).The lowest resistance rate was to amikacin (3.8%), followed by levofloxacin (10.9%), imipenem (19.1%), and meropenem (19.9%). Resistance rates to cefoperazone/sulbactam ( χ2=9.982 0, P=0.001 6), piperacillin/tazobactam ( χ2=10.110 0, P=0.001 5), ceftazidime ( χ2=3.849 0, P=0.049 8), cefotaxime ( χ2=7.605 0, P=0.005 8), cefepime ( χ2=13.510 0, P=0.000 2), aztreonam ( χ2=6.457 0, P=0.011 1), imipenem ( χ2=4.672 0, P=0.030 7), and levofloxacin ( χ2=7.555 0, P=0.006 0) showed an annual increasing trend. The main carbapenemase genes were blaNDM-5 (42.2%, 127/301), blaNDM-1 (33.9%, 102/301), and blaKPC-2 (17.3%, 52/301). Patients with KPC-2-producing strains (median age, 240 days) were older than those with NDM-1/NDM-5-producing strains (median age, 40 days) ( χ2=22.620 0, P<0.000 1). In neonatal wards, the detection rate of NDM-KP was higher than that of KPC-KP (64.6%, 148/229 vs. 26.9%, 14/52, χ2=24.680 0, P<0.000 1), whereas in ICUs, it was lower (6.1%, 14/229 vs. 26.9%, 14/52, χ2=20.450 0, P<0.000 1). Conclusion:In Chongqing region, the isolation rate of K. pneumoniae from sputum was the highest with most cases from neonatal wards. Resistance to carbapenems showed an upward trend. BlaNDM-5 was the predominant genotype in pediatric CRKP. Patients with KPC-KP were older than those with NDM-KP. NDM-KP predominated in neonatal wards, while KPC-KP predominated in ICUs, with KPC-KP showing higher antimicrobial resistance.
8.Performance validation and clinical application evaluation of fluorescent magnetic particle chemiluminescence method for the determination of sIgE
Wenqi SHAO ; Mi ZHOU ; Jing ZHU ; Baishen PAN ; Beili WANG ; Wei GUO
Chinese Journal of Preventive Medicine 2025;59(9):1427-1433
To evaluate the analytical performance of a specific IgE (sIgE) quantitative detection system and explore the clinical application effect of dust mite extract and component detection. The fluorescent magnetic particle chemiluminescence method was used to verify the analytical performance of sIgE for house dust mite (D1), dust mite (D2) extracts, and their components (Der p 1, Der p 2, Der p 10, and Der p 23), including precision, limit of blank (LoB), limit of detection (LoD), linear range, and interfering factors. This is a retrospective cohort study. A total of 50 patients with allergic rhinitis and 50 patients with allergic asthma diagnosed at Zhongshan Hospital Affiliated to Fudan University from January 2022 to August 2023 were selected, along with 70 apparently healthy individuals who underwent physical examinations in the hospital as the healthy control group. The positive rates of each sIgE component in the three groups were compared, and the receiver operating characteristic (ROC) curve for diagnosing dust mite allergy was plotted. The results showed that the fluorescent magnetic particle chemiluminescence method for detecting sIgE demonstrated good repeatability and intermediate precision within the range of 0.1-100 kU/L. The LoB, LoD, and linear range all met the specified requirements. Except for Der p 10, which was interfered by the presence of conjugated bilirubin and free bilirubin (exceeding 40 mg/dl), the detection of other allergens was not significantly affected by common endogenous substances. In healthy individuals, 10% had positive sIgE for dustmite extract; in asthmatic and allergic rhinitis patients, the positive rates were 70% and 82%, respectively. The double positive rate of D1 and D2 in the healthy group was 8.6%, while in asthmatic and allergic rhinitis patients, it was 66% and 70%, respectively. When 0.35 kU/L was used as the threshold, the sensitivity of sIgE for dust mite extract to predict component positivity was 100%, specificity was 61.5%, positive predictive value (PPV) was 80.2%, and negative predictive value (NPV) was 100%. When the threshold was optimized to 0.78 kU/L, the sensitivity was 96.8%, specificity was 92.1%, PPV was 95.2%, and NPV was 94.6%. In conclusion, the repeatability, intermediate precision, LoB, LoD, linear range, and anti-interference ability of the fluorescent magnetic particle chemiluminescence method for detecting sIgE meet the requirements of laboratory quality management. This ensures detection quality, meets clinical needs, and can be used for the auxiliary diagnosis of allergic diseases.
9.Construction and Application Promotion of Core Medical Skills of"Tonifying Kidney Essence"in Zou's Nephrology Depart-ment
Gang WANG ; Yanqin ZOU ; Wei SUN ; Enchao ZHOU ; Lan YI ; Jun ZHU ; Wei KONG ; Jing ZHAO ; Liang CAO ; Hengbin WANG
Journal of Nanjing University of Traditional Chinese Medicine 2025;41(3):281-287
Professor Zou Yunxiang proposed the"kidney essence theory"in 1955,which believes that the kidney,as an important excretory organ in the human body,participates in the body's metabolism,and the basis for producing this effect is the essence of the kidney.Subsequently,the Zou nephrology team established the core medical technique of"tonifying the kidney element"based on this foundation,constructed a system of syndrome differentiation and treatment for chronic kidney disease,proposed the traditional Chinese medicine names,causes,and mechanisms of chronic kidney disease,as well as four major methods for diagnosing and treating chronic kidney disease,and developed representative drugs representing the core medical technique of"tonifying the kidney element"-Huang-zhi Yishen Capsules and Shenwu Yishen Tablets.In addition,the Zou nephrology team has extensively applied and promoted the core medical technique of"tonifying the kidney element".
10.Distribution and drug resistance of carbapenem-resistant gram-negative bacilli isolated from environment of ICU
Chunyan LI ; Jing ZHANG ; Liang TIAN ; Yilun ZHOU ; Bin WANG ; Mei FENG ; Yuan LI ; Shan WANG ; Wei JI
Chinese Journal of Nosocomiology 2025;35(17):2675-2680
OBJECTIVE To explore the isolation rates,drug resistance and molecular epidemiological characteristics of carbapenem-resistant gram-negative bacilli(CRGNB)isolated from intensive care units(ICU)of a tertiary hos-pital so as to provide bases for prevention and control of the nosocomial infections caused by CRGNB.METHODS The environmental surfaces that were high frequently contacted by the patients with CRGNB infections[carbapen-em-resistant Klebsiella pneumoniae(CRKP),carbapenem-resistant Acinetobacter baumannii(CRAB),carbap-enem-resistant Pseudomonas aeruginosa(CRPA)]and their hands were randomly sampled from the ICU of a ter-tiary three-A hospital from Apr.2024 to Aug.2024.Multilocus sequence typing(MLST)and detection of drug re-sistance genes were performed by means of complete genome sequencing technique and bioinformatics,and the ho-mology between the CRGNB strains isolated from the patients and the strains isolated from their surrounding was observed.RESULTS Totally 30(7.85%)strains of CRGNB were isolated,23(6.02%)of which were CRKP,7(1.83%)were CRAB,and no strain of CRPA was detected.The molecular subtyping showed that ST 11(93.33%)was dominant among the CRKP strains,and ST2(69.23%)was dominant among the CRAB strains.The phylogenetic analysis indicated that there were clonal transmission tendencies of CRKP-ST11 and CRAB-ST2.The analysis of drug resistance genes showed that the CRAB strains mainly carried ant(3")-lla(100%),blaOXA-23(92.31%)and amvA(92.31%);blaOXA-23 and blaOXA-66 were the major carbapenems resistance genes;the CRKP strains mainly carried the drug resistance genes emrDh,rmtB1,fosA and kdeA(all were 96.67%),followed by the carbapenems resistance gene blaKPC-2(90.00%).CONCLUSIONS ST11 is the predomi-nant molecular subtype for CRGNB among the CRKP strains isolated from the ICU,anf ST2 predominant among the CRAB strains;the carrying rates of drug resistance genes are high.There is risk of clonal transmission.It is necessary to strengthen the monitoring and take comprehensive infection control measures so as to reduce the incidence of nosocomial infections.

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