1.Compact Fundus Imaging System Using Shack-Hartmann Wavefront Sensing for High-speed Auto-focus
Zhe-Kai LIN ; Long CHEN ; Geng-Yong ZHENG ; Jin-Tian HUANG ; Jia-Xin DONG ; Shang-Pan YANG ; Wen-Zheng DING ; Ding-An HAN ; Xue-Hua WANG ; Ya-Guang ZENG
Progress in Biochemistry and Biophysics 2026;53(4):1076-1086
ObjectiveThe widespread adoption of portable fundus cameras for primary care and community screening is hindered by limitations in current autofocus(AF) technologies. Image-based methods relying on sharpness evaluation require iterative searches, resulting in slow convergence, while projection-based techniques are susceptible to optical artifacts and calibration errors. To address these challenges, this study introduces a novel AF system based on direct wavefront sensing, designed to deliver simultaneous high speed, high precision, and operational robustness within the compact form factor essential for portable ophthalmic devices. MethodsOur approach fundamentally reimagines the AF process by directly measuring the ocular wavefront aberration. We developed a custom portable fundus camera integrating a miniaturized Shack-Hartmann wavefront sensor (SHWS) into the optical path. An 850 nm laser diode projects a point source onto the retina via oblique illumination to minimize corneal reflections. Light scattered from this spot carries the eye’s refractive error through the imaging optics and is directed to the SHWS, positioned at a plane optically conjugate to the primary color CMOS imaging sensor. A microlens array within the SHWS samples the incident wavefront, generating a pattern of focal spots on a CCD. Real-time centroid analysis of these spots provides a map of local wavefront slopes. These measurements are processed through a singular value decomposition (SVD) algorithm to fit a Zernike polynomial basis set, enabling real-time reconstruction of the wavefront phase. The defocus component (S) is extracted from the second-order Zernike coefficients, providing a direct, quantitative measure of the refractive error in diopters. This value serves as a precise error signal in a closed-loop control system, which commands a voice-coil actuated focusing lens to its null position in a single, deterministic step, eliminating the need for iterative search algorithms. ResultsComprehensive evaluation demonstrated the system’s high performance. Testing on a calibrated model eye (OEMI-7) established a highly linear relationship between the computed defocus S and the focusing lens position across a ±20 Diopter (D) compensation range, achievable within a 5 mm mechanical travel. The system achieved a focusing precision of 0.08 D, corresponding to an 18-fold improvement over a conventional projection spot-size method tested under identical conditions. The total focus acquisition time, encompassing wavefront measurement, computation, and lens actuation, averaged under 0.5 s. Clinical validation with 25 human volunteers (50 eyes, refractive range -15 D to +10 D) confirmed practical efficacy. The wavefront-sensing AF succeeded in 92% of attempts with a mean time of 0.5 s, substantially outperforming a projection-based benchmark which achieved only a 32% success rate with an average time of 4.25 s. The system provided instantaneous directional guidance and maintained stability during minor ocular movements. Objective assessment of image quality, via amplitude contrast of retinal vasculature, showed consistent and significant enhancement following AF correction across the entire tested diopter range. ConclusionThis work successfully implements and validates a direct wavefront-sensing autofocus paradigm for portable fundus cameras. By directly quantifying and compensating for the optical defocus aberration, this method bypasses the fundamental limitations of image-processing and projection-based techniques, enabling rapid, precise, and deterministic diopter compensation. The developed system delivers an exceptional combination of a wide operational range (±20 D), high accuracy (0.08 D), fast convergence (0.5 s), and a compact physical footprint. This technology provides a practical and high-performance focusing solution capable of enhancing the reliability, throughput, and diagnostic utility of portable retinal imaging in large-scale screening applications. Future efforts will be directed towards system cost optimization and performance adaptation for diverse ocular conditions.
2.Analysis of Nitrofuran Metabolites in Meat by Solid-Phase Extraction of Porous Organic Polymer Combined with Liquid Chromatography-Tandem Mass Spectrometry
Yao CHEN ; Ying-Jiao DONG ; Jia-Yi LI ; Rui-Jie WANG ; Zhi-Kai HONG ; Guan-Hua WANG
Chinese Journal of Analytical Chemistry 2025;53(5):804-813
In this work,with tris(4-aminophenyl)amine(TAPA)and 1,3,5-tris(4-formylphenyl)benzene(TFPB)as monomers,an imine-type porous organic polymer,TAPA-TFPB,was synthesized using a simple method under the catalysis of acetic acid.The material TAPA-TFPB was used as solid-phase extraction adsorbent and combined with ultra-performance liquid chromatography/quadrupole time-of-flight-tandem mass spectrometry(UHPLC-QTOF-MS)to establish a detection method for four kinds of nitrofuran metabolites(NFMs)residues in meat samples.The parameters of the adsorbent dosage,the pH value and volume of sample,and the type and volume of washing and eluent solvents were optimized,respectively.Under the optimal extraction conditions,low detection limits(0.11-1.60 μg/kg)were achieved for four kinds of NFMs.At three different spiked levels,the intra-day and inter-day precisions(Relative standard deviations)were 2.8% -10.9% and 4.3% -16.2%,respectively,and the spiked recoveries were 72.0% -107.2%.The results showed that the method chould be used for efficient extraction and analysis of trace NFMs residues in meat samples,indicating that TAPA-TFPB was a kind of promising SPE adsorbent.
3.Effect and mechanism of Xintong Granules in ameliorating myocardial ischemia-reperfusion injury in rats by regulating gut microbiota.
Yun-Jia WANG ; Ji-Dong ZHOU ; Qiu-Yu SU ; Jing-Chun YAO ; Rui-Qiang SU ; Guo-Fei QIN ; Gui-Min ZHANG ; Hong-Bao LIANG ; Shuai FENG ; Jia-Cheng ZHANG
China Journal of Chinese Materia Medica 2025;50(14):4003-4014
This study investigates the mechanism by which Xintong Granules improve myocardial ischemia-reperfusion injury(MIRI) through the regulation of gut microbiota and their metabolites, specifically short-chain fatty acids(SCFAs). Rats were randomly divided based on body weight into the sham operation group, model group, low-dose Xintong Granules group(1.43 g·kg~(-1)·d~(-1)), medium-dose Xintong Granules group(2.86 g·kg~(-1)·d~(-1)), high-dose Xintong Granules group(5.72 g·kg~(-1)·d~(-1)), and metoprolol group(10 mg·kg~(-1)·d~(-1)). After 14 days of pre-administration, the MIRI rat model was established by ligating the left anterior descending coronary artery. The myocardial infarction area was assessed using the 2,3,5-triphenyltetrazolium chloride(TTC) staining method. Apoptosis in tissue cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL) assay. Pathological changes in myocardial cells and colonic tissue were observed using hematoxylin-eosin(HE) staining. The levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), interleukin-6(IL-6), creatine kinase MB isoenzyme(CK-MB), and cardiac troponin T(cTnT) in rat serum were quantitatively measured using enzyme-linked immunosorbent assay(ELISA) kits. The activities of lactate dehydrogenase(LDH), creatine kinase(CK), and superoxide dismutase(SOD) in myocardial tissue, as well as the level of malondialdehyde(MDA), were determined using colorimetric assays. Gut microbiota composition was analyzed by 16S rDNA sequencing, and fecal SCFAs were quantified using gas chromatography-mass spectrometry(GC-MS). The results show that Xintong Granules significantly reduced the myocardial infarction area, suppressed cardiomyocyte apoptosis, and decreased serum levels of pro-inflammatory cytokines(TNF-α, IL-1β, and IL-6), myocardial injury markers(CK-MB, cTnT, LDH, and CK), and oxidative stress marker MDA. Additionally, Xintong Granules significantly improved intestinal inflammation in MIRI rats, regulated gut microbiota composition and diversity, and increased the levels of SCFAs(acetate, propionate, isobutyrate, etc.). In summary, Xintong Granules effectively alleviate MIRI symptoms. This study preliminarily confirms that Xintong Granules exert their inhibitory effects on MIRI by regulating gut microbiota imbalance and increasing SCFA levels.
Animals
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Gastrointestinal Microbiome/drug effects*
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Rats
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Male
;
Myocardial Reperfusion Injury/genetics*
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Drugs, Chinese Herbal/administration & dosage*
;
Rats, Sprague-Dawley
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Apoptosis/drug effects*
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Humans
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Tumor Necrosis Factor-alpha/metabolism*
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Interleukin-6/genetics*
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Malondialdehyde/metabolism*
4.Preparation of baicalin-berberine complex nanocrystal enteric microspheres and pharmacodynamic evaluation of ulcerative colitis treatment in rats.
Xiao-Chao HUANG ; Yi-Wen HU ; Peng-Yu SHEN ; Rui-Hong JIAN ; Dong-Li QI ; Zhi-Dong LIU ; Jia-Xin PI
China Journal of Chinese Materia Medica 2025;50(15):4263-4274
To enhance the therapeutic efficacy of the baicalin-berberine complex(BA-BBR) in the treatment of ulcerative colitis(UC), BA-BBR nanocrystal microspheres(BA-BBR NC MS) were prepared using the dropping method. The microspheres were characterized in terms of morphology, particle size, differential scanning calorimetry(DSC), and powder X-ray diffraction(XRD). The release profiles of BA and BBR from the microspheres were measured, and the drug release mechanism was investigated. A rat model of UC was induced by 5% dextran sodium sulfate(DSS) and treated continuously for 7 days to evaluate the therapeutic effects of different formulations. The results showed that the prepared BA-BBR MS and BA-BBR NC MS were uniform gel spheres with particle sizes of(1.77±0.16) mm and(1.67±0.08) mm, respectively. After drying, the gels collapsed inward and exhibited a rough surface. During the preparation process, the BA-BBR nanocrystals(BA-BBR NC) were uniformly encapsulated within the microspheres. The release profiles of the microspheres followed a first-order kinetic model, and the 12-hour cumulative release of BA and BBR from BA-BBR NC MS was higher than that from BA-BBR MS. Compared with BA-BBR, BA-BBR NC, and BA-BBR MS, BA-BBR NC MS further alleviated UC symptoms in rats, most significantly reducing the levels of TNF-α, IL-1β, IL-6, and MPO, while increasing the level of IL-4 in colon tissues. These results indicate that BA-BBR NC MS, based on a "nano-in-micro" design, can deliver BA-BBR to the intestine and exert significant therapeutic effects in a UC rat model, suggesting it as a promising new strategy for the treatment of UC.
Animals
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Colitis, Ulcerative/metabolism*
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Rats
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Nanoparticles/chemistry*
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Microspheres
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Male
;
Berberine/administration & dosage*
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Flavonoids/administration & dosage*
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Rats, Sprague-Dawley
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Drugs, Chinese Herbal/administration & dosage*
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Humans
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Particle Size
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Tumor Necrosis Factor-alpha/immunology*
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Drug Liberation
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Drug Compounding
6.Mechanism exploration and basic research on the repair of diabetic foot ulcer.
Hong-Rui WANG ; Kang WU ; Jia-Dong ZHANG ; Yong HU ; Xian LI
China Journal of Orthopaedics and Traumatology 2025;38(9):964-968
Diabetic foot ulcer (DFU) is one of the common chronic complications in diabetic patients. Its course is complex and the therapeutic effect is limited, which seriously affects the quality of life of patients. In recent years, significant progress has been made in the research on the mechanism of DFU wound repair. Studies have found that dysregulation of the inflammatory microenvironment, vascular dysfunction, obstruction of re-epithelialization, insufficient collagen deposition, and formation of wound biofilms are the core factors affecting healing. Intervention strategies targeting these mechanisms have become research hotspots. For instance, hydrogel scaffolds could provide an appropriate healing microenvironment, immune regulation strategies could promote inflammation resolution and tissue remodeling, and stem cell exosomes and growth factors have shown good potential in cell migration, angiogenesis, and matrix remodeling. Various natural compounds, such as components from Chinese herbal medicines, are also applied in diabetic foot ulcers. And it demonstrates excellent anti-inflammatory and restorative capabilities. However, existing research still faces obstacles in clinical translation, such as the immaturity of individualized treatment strategies and the difficulty of animal models in simulating complex clinical situations. By systematically summarizing the latest research progress on the repair mechanism of DFU, it is expected to provide theoretical support for precise treatment.
Humans
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Diabetic Foot/drug therapy*
;
Wound Healing
;
Animals
7.Novel biallelic HFM1 variants cause severe oligozoospermia with favorable intracytoplasmic sperm injection outcome.
Liu LIU ; Yi-Ling ZHOU ; Wei-Dong TIAN ; Feng JIANG ; Jia-Xiong WANG ; Feng ZHANG ; Chun-Yu LIU ; Hong ZHU
Asian Journal of Andrology 2025;27(6):751-756
Male factors contribute to 50% of infertility cases, with 20%-30% of cases being solely attributed to male infertility. Helicase for meiosis 1 ( HFM1 ) plays a crucial role in ensuring proper crossover formation and synapsis of homologous chromosomes during meiosis, an essential process in gametogenesis. HFM1 gene mutations are associated with male infertility, particularly in cases of non-obstructive azoospermia and severe oligozoospermia. However, the effects of intracytoplasmic sperm injection (ICSI) in HFM1 -related infertility cases remain inadequately explored. This study identified novel biallelic HFM1 variants through whole-exome sequencing (WES) in a Chinese patient with severe oligozoospermia, which was confirmed by Sanger sequencing. The pathogenicity of these variants was assessed using real-time quantitative polymerase chain reaction (RT-qPCR) and immunoblotting, which revealed a significant reduction in HFM1 mRNA and protein levels in spermatozoa compared to those in a healthy control. Transmission electron microscopy revealed morphological abnormalities in sperm cells, including defects in the head and flagellum. Despite these abnormalities, ICSI treatment resulted in a favorable fertility outcome for the patient, indicating that assisted reproductive techniques (ART) can be effective in managing HFM1 -related male infertility. These findings offer valuable insights into the management of such cases.
Humans
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Male
;
Sperm Injections, Intracytoplasmic
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Oligospermia/therapy*
;
Adult
;
Spermatozoa/ultrastructure*
;
Exome Sequencing
;
Mutation
8.Glucocorticoid Discontinuation in Patients with Rheumatoid Arthritis under Background of Chinese Medicine: Challenges and Potentials Coexist.
Chuan-Hui YAO ; Chi ZHANG ; Meng-Ge SONG ; Cong-Min XIA ; Tian CHANG ; Xie-Li MA ; Wei-Xiang LIU ; Zi-Xia LIU ; Jia-Meng LIU ; Xiao-Po TANG ; Ying LIU ; Jian LIU ; Jiang-Yun PENG ; Dong-Yi HE ; Qing-Chun HUANG ; Ming-Li GAO ; Jian-Ping YU ; Wei LIU ; Jian-Yong ZHANG ; Yue-Lan ZHU ; Xiu-Juan HOU ; Hai-Dong WANG ; Yong-Fei FANG ; Yue WANG ; Yin SU ; Xin-Ping TIAN ; Ai-Ping LYU ; Xun GONG ; Quan JIANG
Chinese journal of integrative medicine 2025;31(7):581-589
OBJECTIVE:
To evaluate the dynamic changes of glucocorticoid (GC) dose and the feasibility of GC discontinuation in rheumatoid arthritis (RA) patients under the background of Chinese medicine (CM).
METHODS:
This multicenter retrospective cohort study included 1,196 RA patients enrolled in the China Rheumatoid Arthritis Registry of Patients with Chinese Medicine (CERTAIN) from September 1, 2019 to December 4, 2023, who initiated GC therapy. Participants were divided into the Western medicine (WM) and integrative medicine (IM, combination of CM and WM) groups based on medication regimen. Follow-up was performed at least every 3 months to assess dynamic changes in GC dose. Changes in GC dose were analyzed by generalized estimator equation, the probability of GC discontinuation was assessed using Kaplan-Meier curve, and predictors of GC discontinuation were analyzed by Cox regression. Patients with <12 months of follow-up were excluded for the sensitivity analysis.
RESULTS:
Among 1,196 patients (85.4% female; median age 56.4 years), 880 (73.6%) received IM. Over a median 12-month follow-up, 34.3% (410 cases) discontinued GC, with significantly higher rates in the IM group (40.8% vs. 16.1% in WM; P<0.05). GC dose declined progressively, with IM patients demonstrating faster reductions (median 3.75 mg vs. 5.00 mg in WM at 12 months; P<0.05). Multivariate Cox analysis identified age <60 years [P<0.001, hazard ratios (HR)=2.142, 95% confidence interval (CI): 1.523-3.012], IM therapy (P=0.001, HR=2.175, 95% CI: 1.369-3.456), baseline GC dose ⩽7.5 mg (P=0.003, HR=1.637, 95% CI: 1.177-2.275), and absence of non-steroidal anti-inflammatory drugs use (P=0.001, HR=2.546, 95% CI: 1.432-4.527) as significant predictors of GC discontinuation. Sensitivity analysis (545 cases) confirmed these findings.
CONCLUSIONS
RA patients receiving CM face difficulties in following guideline-recommended GC discontinuation protocols. IM can promote GC discontinuation and is a promising strategy to reduce GC dependency in RA management. (Trial registration: ClinicalTrials.gov, No. NCT05219214).
Adult
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Aged
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Female
;
Humans
;
Male
;
Middle Aged
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Arthritis, Rheumatoid/drug therapy*
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Glucocorticoids/therapeutic use*
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Medicine, Chinese Traditional
;
Retrospective Studies
9.Distribution and resistance profiles of bacterial strains isolated from cerebrospinal fluid in hospitals across China:results from the CHINET Antimicrobial Resistance Surveillance Program,2015-2021
Juan MA ; Lixia ZHANG ; Yang YANG ; Fupin HU ; Demei ZHU ; Han SHEN ; Wanqing ZHOU ; Wenen LIU ; Yanming LI ; Yi XIE ; Mei KANG ; Dawen GUO ; Jinying ZHAO ; Zhidong HU ; Jin LI ; Shanmei WANG ; Yafei CHU ; Yunsong YU ; Jie LIN ; Yingchun XU ; Xiaojiang ZHANG ; Jihong LI ; Bin SHAN ; Yan DU ; Ping JI ; Fengbo ZHANG ; Chao ZHUO ; Danhong SU ; Lianhua WEI ; Fengmei ZOU ; Xiaobo MA ; Yanping ZHENG ; Yuanhong XU ; Ying HUANG ; Yunzhuo CHU ; Sufei TIAN ; Hua YU ; Xiangning HUANG ; Sufang GUO ; Xuesong XU ; Chao YAN ; Fangfang HU ; Yan JIN ; Chunhong SHAO ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Fang DONG ; Zhiyong LÜ ; Lei ZHU ; Jinhua MENG ; Shuping ZHOU ; Yan ZHOU ; Chuanqing WANG ; Pan FU ; Yunjian HU ; Xiaoman AI ; Ziyong SUN ; Zhongju CHEN ; Hong ZHANG ; Chun WANG ; Yuxing NI ; Jingyong SUN ; Kaizhen WEN ; Yirong ZHANG ; Ruyi GUO ; Yan ZHU ; Jinju DUAN ; Jianbang KANG ; Xuefei HU ; Shifu WANG ; Yunsheng CHEN ; Qing MENG ; Yong ZHAO ; Ping GONG ; Ruizhong WANG ; Hua FANG ; Jilu SHEN ; Jiangshan LIU ; Hongqin GU ; Jiao FENG ; Shunhong XUE ; Bixia YU ; Wen HE ; Lin JIANG ; Longfeng LIAO ; Chunlei YUE ; Wenhui HUANG
Chinese Journal of Infection and Chemotherapy 2025;25(3):279-289
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.
10.Changing antibiotic resistance profiles of the bacterial strains isolated from geriatric patients in hospitals across China:data from CHINET Antimicrobial Resistance Surveillance Program,2015-2021
Xiaoman AI ; Yunjian HU ; Chunyue GE ; Yang YANG ; Fupin HU ; Demei ZHU ; Yingchun XU ; Xiaojiang ZHANG ; Hui LI ; Ping JI ; Yi XIE ; Mei KANG ; Chuanqing WANG ; Pan FU ; Yuanhong XU ; Ying HUANG ; Ziyong SUN ; Zhongju CHEN ; Yuxing NI ; Jingyong SUN ; Yunzhuo CHU ; Sufei TIAN ; Zhidong HU ; Jin LI ; Yunsong YU ; Jie LIN ; Bin SHAN ; Yan DU ; Sufang GUO ; Lianhua WEI ; Fengmei ZOU ; Hong ZHANG ; Chun WANG ; Chao ZHUO ; Danhong SU ; Dawen GUO ; Jinying ZHAO ; Hua YU ; Xiangning HUANG ; Wen'en LIU ; Yanming LI ; Yan JIN ; Chunhong SHAO ; Xuesong XU ; Chao YAN ; Shanmei WANG ; Yafei CHU ; Lixia ZHANG ; Juan MA ; Shuping ZHOU ; Yan ZHOU ; Lei ZHU ; Jinhua MENG ; Fang DONG ; Zhiyong LÜ ; Fangfang HU ; Han SHEN ; Wanqing ZHOU ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Jihong LI ; Jinju DUAN ; Jianbang KANG ; Xiaobo MA ; Yanping ZHENG ; Ruyi GUO ; Yan ZHU ; Yunsheng CHEN ; Qing MENG ; Shifu WANG ; Xuefei HU ; Jilu SHEN ; Wenhui HUANG ; Ruizhong WANG ; Hua FANG ; Bixia YU ; Yong ZHAO ; Ping GONG ; Kaizhen WENG ; Yirong ZHANG ; Jiangshan LIU ; Longfeng LIAO ; Hongqin GU ; Lin JIANG ; Wen HE ; Shunhong XUE ; Jiao FENG ; Chunlei YUE
Chinese Journal of Infection and Chemotherapy 2025;25(3):290-302
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.

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