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.

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.

AIM:This study aims to investigate the protective effect of Buyang-Huanwu decoction(BYHWD)on cerebral ischemia-reperfusion injury(CIRI)in rats,focusing on its role in regulating the autophagy of cerebral micro-vascular endothelial cells(BMECs).METHODS:(1)We established a rat model of middle cerebral artery occlusion/re-perfusion(MCAO/R)and divided the subjects into four groups:sham group,model(MCAO/R)group,BYHWD group,and 3-n-butylphthalide(NBP)group.Neurological deficits were assessed using the Zea Longa score,while the volume of cerebral infarction was measured through 2,3,5-triphenyltetrazolium chloride(TTC)staining.Pathological damage in the ischemic penumbra was evaluated using HE staining,and blood-brain barrier(BBB)permeability was assessed by Evans blue(EB)staining.The ultrastructure of BMECs was analyzed by transmission electron microscopy,and the co-expres-sion and positive cell rate of microtubule-associated protein 1 light chain 3(LC3)in BMECs were determined through im-munofluorescence double staining.Additionally,the protein expression levels of ZO-1,claudin-5 and occludin in the cor-tical region of the ischemic penumbra in rats were examined using Western blot analysis.(2)A rat BMEC model of oxy-gen-glucose deprivation/reoxygenation(OGD/R)was also established.Rat BMECs were categorized into normal control(CON),OGD/R,dimethyl sulfoxide(DMSO),rapamycin and 3-methyladenine groups to observe autophagy levels by monodansylcadaverine(MDC)staining.Furthermore,rat BMECs were divided into CON,OGD/R,BYHWD-containing serum(BHDS)and NBP groups.The cell autophagy was assessed by MDC staining and Western blot,while cell viability was measured by CCK-8 assay.RESULTS:(1)The rats in MCAO/R group exhibited significantly higher neurological scores(P＜0.01)and increased cerebral infarction volumes(P＜0.01)compared with sham group.Severe damage in the ischemic penumbra was observed,characterized by disordered tissue structure,widened intercellular spaces,and compro-mised cellular integrity.The EB dye permeability was notably elevated(P＜0.01),and BMECs showed structural destruc-tion,including damaged cell membranes,swollen Golgi apparatus,dilated endoplasmic reticulum vesicles,and damaged mitochondria.The ratio of LC3+CD31+/CD31+and the protein levels of ZO-1,claudin-5 and occludin were significantly el-evated(P＜0.01).In contrast,the rats in BYHWD and NBP groups demonstrated lower neurological scores(P＜0.01)and reduced cerebral infarction volumes(P＜0.01).Furthermore,EB permeability decreased(P＜0.01),BMEC morphol-ogy improved,and the protein expression levels of ZO-1,claudin-5 and occludin increased(P＜0.05).(2)Rat BMECs in OGD/R group had a significantly elevated autophagy level compared with CON group(P＜0.01),with increased expres-sion of LC3 and beclin-1 proteins and decreased level of P62 protein(P＜0.05).Notably,the cells in BHDS and NBP groups displayed decreased autophagy level compared with OGD/R group,with increased cell viability(P＜0.01),re-duced LC3 and beclin-1 protein expression,and increased P62 protein expression(P＜0.05).CONCLUSION:Buyang-Huanwu decoction alleviates cerebral ischemia-reperfusion injury in rats by inhibiting the autophagy of cerebral microvas-cular endothelial cells.

Objective To comparatively analyze the quantitative parameters of culprit and non-culprit plaques in patients with acute coronary syndromes(ACS)with a noninvasive technique of coronary computed tomography angiography(CCTA),and to explore the correlation between the quantitative parameters of plaques and culprit plaques.Methods Data were restrospectively collected from 51 ACS patients admitted in some hospital from January to December 2021.The coronary atherosclerotic plaques shown by invasive catheter angiography(ICA)that caused hemodynamic abnormalities and were treated with stenting were defined as offender plaques and enrolled into a culprit plaque group(56 culprit plaques),and other plaques were regarded as non-culprit plaques and divied into a non-culprit plaque group(164 non-culprit plaques).The relationship between culprit plaque and luminal stenosis was analyzed using the chi-square test,and quantitative plaque metrics were compared between the groups.The corelation between quantitative indicators and culprit plaque was analyzed using univariate Logistic regression,and multifactorial Logistic regression analysis was carried out.Statistical analysis was performed with SPSS 23.0 software.Results Analysis of plaque imaging data showed that culprit plaque was significantly associated with the degree of luminal stenosis(P<0.05).Statistically significant differences were found beween the two groups and between the culprit plaques resulting in moderate or greater luminal stenosis and non-culprit plaques in total plaque length,total plaque load,calcification load,fibrolipid volume,fibrolipid load,necrotic core volume and necrotic core load(all P<0.05).Univariate Logistic regression analysis showed total plaque length,total plaque load,fibrolipid volume,fibrolipid load,necrotic core volume and necrotic core load were all significantly correlated with culprit plaques(all P<0.05);multifactorial Logistic regress indicated total plaque length and fibrous lipid load were independent risk factors for culprit plaques,and the probability of culprit plaques increased to 1.093 and 1.101 times for every one unit increase in total plaque length and fibrolipid load,respectively.Conclusion Such quantitative parameters of plaques as total plaque length,total plaque load,fibrolipid volume,fibrolipid load,necrotic core volume and necrotic core load reflects the characteristics of culprit plaques effectively.Quantitative plaque parameter analysis based on CCTA facilitates clinicians for early assessment of patients with coronary atherosclerosis,which enables early intervention and prevention of acute coronary syndromes.[Chinese Medical Equipment Journal,2025,46(6):65-71]

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective To construct a clinical-radiological nomo-gram model for severe mycoplasma pneumoniae pneumonia coinfec-tion with other pathogens(Co-SMPP)in children.Methods The clinical and radiological data of children with severe mycoplasma pneumoniae pneumonia(SMPP)who underwent nucleic acid testing or bronchoalveolar lavage(BAL)were analyzed retrospectively.The data analysis were performed by using SPSS 27.0 software.The group comparison between simple SMPP and Co-SMPP children was conducted by using t-tests,Mann-Whitney U tests,or chi-square tests.Nomogram analysis was performed by using R software and rms packages.The predictive performance of the model was evaluated by using the receiver operating characteristic(ROC)curve.Results A total of 194 SMPP children were included in the study,including 136 cases(70.1％)with simple SMPP,58 cases(29.9％)with Co-SMPP.The fibrinogen and albumin levels were lower in Co-SMPP children[(3.53±0.85)g/L,41.00(39.03,43.68)g/L]than in simple SMPP children[(3.79±0.80)g/L,42.80(41.00,44.40)g/L],with P values of 0.047 and 0.036,respec-tively.The probability of bronchial stenosis and grid shadow were higher in Co-SMPP children than in simple SMPP children,and there were significant differences between the two groups(P＜0.001,P=0.010).The odds ratio of bronchial stenosis in predicting Co-SMPP children was 14.085.The clinical-radiological nomogram model had an area under the curve(AUC)of 0.840,with sensi-tivity and specificity of 0.756 and 0.848,respectively.Conclusion The nomogram model based on clinical-radiological features can effectively predict Co-SMPP.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

Objective:To investigate the effects of tetramethylpyrazine(TMP)on spinal cord inflammation and phosphatidylinositol 3-kinase/serine-threonine kinase/nuclear factor-κB(PI3K/Akt/NF-κB)signaling pathway in rats with lumbar disc herniation(LDH).Methods:The rats were divided into Control group,lumbar disc herniation group(LDH group),TMP low-dose,high-dose group(TMP-L,TMP-H group),TMP high-dose+PI3K inhibitor group(TMP-H+LY294002 group)by random number table method.LDH rat model was established by autologous nucleus pulposus transplantation and treated with corresponding drugs.After administration,the pain threshold of rats in each group was measured by paw tactile tester and plantar thermal stimulation tester.Hematoxylin-eosin(HE)staining was used to observe the histomorphological changes of dorsal root ganglion.Enzyme linked immunosorbent assay(ELISA)was used to measure the levels of tumor necrosis factor α(TNF-α),interleukin-1β(IL-1β)and interleukin-6(IL-6)in the spinal dorsal horn.Immunohistochemistry was used to detect the expression of ionized calcium binding adapter molecule 1(Iba-1)and c-Fos in the spinal dorsal horn.Western blot was used to detect the expression of PI3K/Akt/NF-κB signaling pathway related proteins,and the ratios of p-PI3K/PI3K,p-Akt/Akt and p-NF-κB p65/NF-κB p65 were calculated.Results:At 24h before intervention,the paw withdrawal mechanical threshold(PWMT)and paw withdrawal thermal latency(PWTL)in the LDH group were lower than those in the Control group(P<0.05).At 24h after intervention,compared with Control group,the LDH group had severe nucleus deviation,blurred nucleoli,large amount of inflammatory cell infiltration and obvious cell swelling,decreased PWMT,PWTL,p-PI3K/PI3K and p-Akt/Akt,and increased levels of TNF-α,IL-1β,IL-6 and Iba-1,c-Fos and p-NF-κB p65/NF-κB p65(P<0.05).Com-pared with the LDH group,the neurons had less nuclear deviation,clearer nucleoli,less cell swelling and inflammatory cell infiltration in the TMP-L group and TMP-H group,and the PWMT,PWTL,p-PI3K/PI3K and p-Akt/Akt were in-creased in turn,while the levels of TNF-α,IL-1β,IL-6 and Iba-1,c-Fos,p-NF-κB p65/NF-κB p65 were decreased in turn(P<0.05).Compared with the TMP-H group,the TMP-H+LY294002 group had more severe pathological dam-age of neurons,obvious nuclear deviation,blurred nucleoli,cell swelling and inflammatory cell infiltration,decreased PWMT,PWTL,p-PI3K/PI3K and p-Akt/Akt,and increased levels of TNF-α,IL-1β,IL-6 and Iba-1,c-Fos and p-NF-κB p65/NF-κB p65(P<0.05).Conclusion:TMP can inhibit the activation of microglia and the expression of Iba-1 and c-Fos,and improve spinal cord inflammation in LDH rats,and its mechanism may be related to the regulation of PI3K/Akt/NF-κB signaling pathway.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.