1.Study on the equivalence of different decoction processes for a shell-based traditional Chinese medicine drug pair based on rat model of hypertension with liver-yang hyperactivity
Minglu LI ; Yuhan CUI ; Fan WU ; Kexin HAN ; Li WU ; Zhuyuan FANG ; Yachun SHU
China Pharmacy 2026;37(10):1283-1289
OBJECTIVE To investigate the equivalence of different decoction processes based on rat model of hypertension with liver-yang hyperactivity. METHODS Inductively coupled plasma mass spectrometry (ICP-MS) was used to compare the dissolution differences of inorganic elements in the powder-directly-decocted decoction versus the pieces-decocted-first decoction of Ostreae Concha- Haliotidis Concha- Margaritifera Concha drug pair. Six SD rats were included in the normal group. The spontaneously hypertensive rats were given Aconite decoction for six weeks to induce the hypertension model with liver-yang hyperactivity. After successful modeling, 48 rats were randomly divided into the model group, the captopril group [positive control, 8 mL/(kg·d) ] , as well as low-, medium-, and high-dose groups of pieces decocted first or directly powder decocted [2.02, 4.05, 8.10 mL/(kg·d) ] , with 6 rats in each group. Each group received the corresponding drug or equal volume of pure water intragastrically, once a day, for two consecutive weeks. After the last administration, the degree of irritability, facial temperature, pressure pain threshold, blood pressure, and pathological changes of the thoracic aorta were observed in each group. Serum nitric oxide (NO) and plasma angiotensin Ⅱ (Ang Ⅱ), renin, and aldosterone (ALD) levels were also measured. RESULTS ICP-MS analysis results showed statistically significant differences in the contents of macroelements Li, Na, Mg, Ca, Mn, Ga, Sr, Mo, Cd, Sn, and Sb, between the powder-directly-decocted decoction and the pieces-decocted-first decoction ( P <0.05) ,the elements P, Cr, Fe, Ni, Zn, Hg, Tl, and Pb were not detected in either decoction. Animal experiments showed that after two weeks of administration, compared with the model group, the facial temperature, and blood pressure decreased in all treatment groups, while the pressure pain threshold increased; plasma levels of Ang Ⅱ, renin and ALD, as well as the serum level of NO were all decreased, and thoracic aortic media thickness was significantly reduced, most of the differences in the above indicators were statistically significant ( P <0.05 or P <0.01 or P <0.001). Pathological observation showed improvement in thoracic aortic pathological injury. CONCLUSIONS The powder-directly-decocted process for the Ostreae Concha- Haliotidis Concha- Margaritifera Concha drug pair significantly promotes the dissolution of key elements such as Ca, Mg, and Sr without increasing the dissolution of harmful elements. It is equivalent to the traditional pieces-decocted-first in alleviating liver-yang hyperactivity syndrome, lowering blood pressure, and protecting the vascular endothelium, and even shows better performance in some indicators.
2.Consistency and risk factor analysis of 2 growth chart in the diagnosis of extrauterine growth restriction in preterm infants with a gestational age at birth of less than 32 weeks
Fan ZHANG ; Xiaohua ZHANG ; Shushu LI ; Shuping HAN
Chinese Journal of Pediatrics 2026;64(1):61-67
Objective:To investigate the diagnostic consistency of extrauterine growth restriction (EUGR) assessed by the Fenton 2013 preterm growth charts (Fenton 2013) and the growth charts by International Fetal and Newborn Growth Consortium for the 21st Century (IG-21).Methods:This multicenter retrospective cohort study included 5 591 preterm infants with a gestational age (GA) at birth of less than 32 weeks admitted to 19 member hospitals of the Neonatal Perinatal Collaborative Network of Suxinyun from January 1 st, 2019, to December 31 st, 2024. Clinical data including baseline characteristics, complications, feeding practices and anthropometrics were processed and analyzed. EUGR was assessed using both the Fenton 2013 and the IG-21. A decrease in weight Z-score at discharge compared to admission by more than 1 was defined as longitudinal EUGR, and discharge weight below the P10 for the corresponding corrected GA was defined as cross-sectional EUGR. Diagnostic consistency was assessed using the Kappa coefficient between the 2 standards, and diagnostic performance of the 2 standards was compared using the McNemar test. Risk factors for EUGR under different definitions were analyzed using univariate analysis and multivariate Logistic regression analysis. Results:A total of 5 591 preterm infants were included, with a GA at birth of (29.7±1.6) weeks and a birth weight of (1 360±315) g and at discharge with a corrected GA of (36.3±2.0) weeks and weight of (2 246±370) g. Detection rates of cross-sectional and longitudinal EUGR diagnosed by Fenton 2013 were both higher than those by IG-21 (37.0% (2 214/5 991) vs. 23.7% (1 324/5 591), 61.1% (3 662/5 991) vs. 30.7% (1 714/5 591), χ2=326.77 and 1 358.05, both P<0.001). Using Fenton 2013 as a reference, IG-21 demonstrated superior diagnostic value and consistency in identifying cross-sectional EUGR compared with longitudinal EUGR (sensitivity of 100.0% (3 377/3 377) vs. 99.6% (1 922/1 929), specificity of 59.8% (1 324/2 214) vs. 46.6% (1 707/3 662), positive predictive value of 79.1% (3 377/4 267) vs. 49.6% (1 922/3 877), negative predictive value of 100.0% (1 324/1 324) vs. 99.6% (1 707/1 714), accuracy of 84.1% (4 701/5 591) vs. 64.9% (3 629/5 591), and Kappa 0.64 vs. 0.37, all P<0.001). In multivariate Logistic regression models, risk factors common to EUGR across both standards included smaller GA at birth, lower birth weight, boy, early-onset sepsis, late-onset sepsis and the elder age at full enteral feeding (all P<0.05). Hemodynamically significant patent ductus arteriosus remained an independent risk factor for longitudinal EUGR regardless of whether by the Fenton 2013 or IG-21 standard (adjust odds ratio ( aOR) =1.25 and 1.27, 95% CI 1.09-1.42 and 1.11-1.45). In addition, under the IG-21 standard, severe bronchopulmonary dysplasia was an independent risk factor for cross-sectional EUGR ( aOR=1.54, 95% CI 1.00-2.38), while severe necrotizing enterocolitis was an independent risk factor for longitudinal EUGR ( aOR=2.18, 95% CI 1.01-4.73). Conclusions:IG-21 showed lower detection rates of both cross-sectional and longitudinal EUGR than Fenton 2013, suggesting greater clinical applicability of IG-21 by reducing overdiagnosis while maintaining sensitivity for predicting complications. Across both standards, cross-sectional EUGR facilitates early identification of growth restriction, whereas longitudinal EUGR better tracks dynamic growth patterns and complications of preterm infants.
3.Treatment Principles and Paradigm of Diabetic Microvascular Complications Responding Specifically to Traditional Chinese Medicine
Anzhu WANG ; Xing HANG ; Lili ZHANG ; Xiaorong ZHU ; Dantao PENG ; Ying FAN ; Min ZHANG ; Wenliang LYU ; Guoliang ZHANG ; Xiai WU ; Jia MI ; Jiaxing TIAN ; Wei ZHANG ; Han WANG ; Yuan XU ; .LI PINGPING ; Zhenyu WANG ; Ying ZHANG ; Dongmei SUN ; Yi HE ; Mei MO ; Xiaoxiao ZHANG ; Linhua ZHAO
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(5):272-279
To explore the advantages of traditional Chinese medicine (TCM) and integrative TCM-Western medicine approaches in the treatment of diabetic microvascular complications (DMC), refine key pathophysiological insights and treatment principles, and promote academic innovation and strategic research planning in the prevention and treatment of DMC. The 38th session of the Expert Salon on Diseases Responding Specifically to Traditional Chinese Medicine, hosted by the China Association of Chinese Medicine, was held in Beijing, 2024. Experts in TCM, Western medicine, and interdisciplinary fields convened to conduct a systematic discussion on the pathogenesis, diagnostic and treatment challenges, and mechanism research related to DMC, ultimately forming a consensus on key directions. Four major research recommendations were proposed. The first is addressing clinical bottlenecks in the prevention and control of DMC by optimizing TCM-based evidence evaluation systems. The second is refining TCM core pathogenesis across DMC stages and establishing corresponding "disease-pattern-time" framework. The third is innovating mechanism research strategies to facilitate a shift from holistic regulation to targeted intervention in TCM. The fourth is advancing interdisciplinary collaboration to enhance the role of TCM in new drug development, research prioritization, and guideline formulation. TCM and integrative approaches offer distinct advantages in managing DMC. With a focus on the diseases responding specifically to TCM, strengthening evidence-based support and mechanism interpretation and promoting the integration of clinical care and research innovation will provide strong momentum for the modernization of TCM and the advancement of national health strategies.
4.Consistency and risk factor analysis of 2 growth chart in the diagnosis of extrauterine growth restriction in preterm infants with a gestational age at birth of less than 32 weeks
Fan ZHANG ; Xiaohua ZHANG ; Shushu LI ; Shuping HAN
Chinese Journal of Pediatrics 2026;64(1):61-67
Objective:To investigate the diagnostic consistency of extrauterine growth restriction (EUGR) assessed by the Fenton 2013 preterm growth charts (Fenton 2013) and the growth charts by International Fetal and Newborn Growth Consortium for the 21st Century (IG-21).Methods:This multicenter retrospective cohort study included 5 591 preterm infants with a gestational age (GA) at birth of less than 32 weeks admitted to 19 member hospitals of the Neonatal Perinatal Collaborative Network of Suxinyun from January 1 st, 2019, to December 31 st, 2024. Clinical data including baseline characteristics, complications, feeding practices and anthropometrics were processed and analyzed. EUGR was assessed using both the Fenton 2013 and the IG-21. A decrease in weight Z-score at discharge compared to admission by more than 1 was defined as longitudinal EUGR, and discharge weight below the P10 for the corresponding corrected GA was defined as cross-sectional EUGR. Diagnostic consistency was assessed using the Kappa coefficient between the 2 standards, and diagnostic performance of the 2 standards was compared using the McNemar test. Risk factors for EUGR under different definitions were analyzed using univariate analysis and multivariate Logistic regression analysis. Results:A total of 5 591 preterm infants were included, with a GA at birth of (29.7±1.6) weeks and a birth weight of (1 360±315) g and at discharge with a corrected GA of (36.3±2.0) weeks and weight of (2 246±370) g. Detection rates of cross-sectional and longitudinal EUGR diagnosed by Fenton 2013 were both higher than those by IG-21 (37.0% (2 214/5 991) vs. 23.7% (1 324/5 591), 61.1% (3 662/5 991) vs. 30.7% (1 714/5 591), χ2=326.77 and 1 358.05, both P<0.001). Using Fenton 2013 as a reference, IG-21 demonstrated superior diagnostic value and consistency in identifying cross-sectional EUGR compared with longitudinal EUGR (sensitivity of 100.0% (3 377/3 377) vs. 99.6% (1 922/1 929), specificity of 59.8% (1 324/2 214) vs. 46.6% (1 707/3 662), positive predictive value of 79.1% (3 377/4 267) vs. 49.6% (1 922/3 877), negative predictive value of 100.0% (1 324/1 324) vs. 99.6% (1 707/1 714), accuracy of 84.1% (4 701/5 591) vs. 64.9% (3 629/5 591), and Kappa 0.64 vs. 0.37, all P<0.001). In multivariate Logistic regression models, risk factors common to EUGR across both standards included smaller GA at birth, lower birth weight, boy, early-onset sepsis, late-onset sepsis and the elder age at full enteral feeding (all P<0.05). Hemodynamically significant patent ductus arteriosus remained an independent risk factor for longitudinal EUGR regardless of whether by the Fenton 2013 or IG-21 standard (adjust odds ratio ( aOR) =1.25 and 1.27, 95% CI 1.09-1.42 and 1.11-1.45). In addition, under the IG-21 standard, severe bronchopulmonary dysplasia was an independent risk factor for cross-sectional EUGR ( aOR=1.54, 95% CI 1.00-2.38), while severe necrotizing enterocolitis was an independent risk factor for longitudinal EUGR ( aOR=2.18, 95% CI 1.01-4.73). Conclusions:IG-21 showed lower detection rates of both cross-sectional and longitudinal EUGR than Fenton 2013, suggesting greater clinical applicability of IG-21 by reducing overdiagnosis while maintaining sensitivity for predicting complications. Across both standards, cross-sectional EUGR facilitates early identification of growth restriction, whereas longitudinal EUGR better tracks dynamic growth patterns and complications of preterm infants.
5.Synergistic Mechanisms of Combined Anti-Angiogenic Therapy and Immunotherapy in Non-small Cell Lung Cancer
Tianxiao HAN ; Kezhong CHEN ; Fan YANG ; Xiang YAN
Medical Journal of Peking Union Medical College Hospital 2026;17(3):698-705
In the tumor microenvironment, a bidirectional feedback regulation exists between aberrant angiogenesis and antitumor immunity, which provides a basis for the synergistic effects of antiangiogenic therapy and immunotherapy. The underlying mechanisms include relief of immunosuppression mediated by proangiogenic factors, induction of vascular normalization to reshape the immune microenvironment, and formation of a positive immune-vascular feedback loop. Based on these mechanisms, the combination of antiangiogenic therapy and immunotherapy has demonstrated synergistic efficacy in advanced non-small cell lung cancer (NSCLC) and is gradually being moved forward to the neoadjuvant setting. However, in the perioperative treatment of resectable lung cancer, this regimen still faces challenges, including primary resistance, a brief window of vascular normalization, and an unclear understanding of spatial interaction mechanisms. This review systematically elucidates the synergistic mechanisms of antiangiogenic agents combined with immunotherapy in NSCLC and the latest advances of this combination strategy in the neoadjuvant therapy setting, aiming to provide a reference for clinical practice.
6.Microcirculation and Cerebrovascular Autoregulation in Patients With Mechanical Circulatory Support Devices
Zoe SOULÉ ; Siyu WANG ; Mingfeng CAO ; Han-Gil JEONG ; Yaman B. AHMAD ; Leon FAN ; Glenn WHITMAN ; Sung-Min CHO
Journal of Stroke 2026;28(2):201-217
Acute brain injury (ABI) affects up to one-third of patients using mechanical circulatory support (MCS). In venoarterial extracorporeal membrane oxygenation (VA ECMO), ABI incidence (11%–40%) has not improved in two decades. Conversely, improvements in left ventricular assist devices (LVADs) have reduced the incidence of stroke, although it remains a major complication (10%–30%). The failure of MCS to ensure adequate cerebral protection may impair cerebrovascular autoregulation (CVAR) and disrupt microcirculatory function affected by reduced pulsatility, endothelial injury, acute perturbations in partial pressure of arterial carbon dioxide (PaCO2), and cerebral venous congestion. Here, we review evidence demonstrating that these factors alter microcirculatory dynamics and CVAR, thereby contributing to ABI through shared mechanistic pathways. Current methods for assessing CVAR are reviewed, including invasive indices such as the pressure reactivity index (PRx) from intracranial pressure monitoring and noninvasive metrics such as the cerebral oximetry index (COx) from near-infrared spectroscopy or flow-velocity correlations from transcranial Doppler. Each method is limited by feasibility, signal artifacts, and inter-modality variability. Our review identifies three priority areas for cerebral protection in MCS: preservation of pulse pressure, cautious titration of PaCO2, and integration of CVAR-informed blood pressure management. Preliminary evidence suggests that very low pulse pressure, rapid carbon dioxide correction, and persistent microcirculatory impairment are each associated with ABI risk. Future investigations should focus on validating bedside tools to assess CVAR and microcirculatory integrity, and on determining whether physiological targets derived from these measures can improve neurological outcomes in patients using MCS.
7.Differences in intraocular pressure and anterior segment biometric parameters among Tibetan populations at different altitudes in Xizang autonomous region
Xiaorong* CHEN ; Tianyi* HAN ; Zexi LIU ; Yuanhang SONG ; Dawa XIAO ; Xiang FAN
International Eye Science 2026;26(10):1851-1854
AIM: To compare the differences in intraocular pressure and anterior segment biometric parameters among Tibetan populations permanent residing at different altitudes in Xizang autonomous region, and to explore the impact of high-altitude environments on ocular characteristics.
METHODS:This was a retrospective cross-sectional study. Data were collected from Tibetan patients who visited the People's Hospital of Xizang Autonomous Region from September 2019 to October 2021. Participants were divided into two groups based on their permanent residence altitude: a higher altitude group(2 500-3 750 m)and a very high-altitude group(>3 750 m). The eye with better best corrected visual acuity was selected for each participant. Intraocular pressure, refractive error, and anterior segment biometric measurements \〖white-to-white corneal diameter(WTW), central corneal thickness(CCT), anterior chamber depth(ACD), lens thickness(LT), axial length(AL)\〗 were recorded and compared between the two groups.
RESULTS: A total of 43 Tibetan patients(43 eyes)were enrolled in this study, comprising 23 males and 20 females, with a mean age of 57.88±13.90 y. There were 19 patients(19 eyes)in the very high-altitude group and 24 patients(24 eyes)in the higher altitude group. The mean intraocular pressure in the very high-altitude group was 11.79±1.72 mmHg, which was significantly lower than 13.44±2.43 mmHg in the higher altitude group(P=0.019). CCT in the very high-altitude group was 482.70±23.76 μm, significantly thinner than 503.00±31.09 μm in the higher altitude group(P=0.012). AL in the very high-altitude group was 22.96±0.96 mm, significantly shorter than 23.64±1.10 mm in the higher altitude group(P=0.020). No statistically significant differences were found between the two groups in WTW, ACD, LT, or refractive error(all P>0.05).
CONCLUSION:Among the Tibetan population in Xizang autonomous region, as the altitude of residence increases, intraocular pressure significantly decreases, CCT becomes thinner and AL shortens. These morphological changes suggest possible adaptive remodelling of the eye in very high-altitude environments, and a thinner cornea may be an important factor contributing to the lower measured intraocular pressure values.
8.Establishment of real-time fluorescence quantitative PCR method for detecting the N subgenome of SARS-CoV-2
Taoli HAN ; Zhi ZHANG ; Jiaxin ZHAO ; Pan LU ; Yang JIAO ; Jianhong ZHAO ; Yan GAO ; Shiyao ZHANG ; Kuankuan LIU ; Yujie LIU ; Ru FAN ; Wenjing LI ; Lingli SUN
Chinese Journal of Experimental and Clinical Virology 2025;39(1):96-101
Objective:To establish a fluorescent quantitative RT-PCR assay based on N_sgRNA of SARS-CoV-2 and preliminarily apply it on real samples.Methods:Recombinant plasmid, specific primers and probes of N_sgRNA were designed and synthesized based on Wuhan-Hu-1/2019_MN908947 and synthesis mechanism of subgenomic RNA (sgRNA). Using recombinant plasmid as amplification templates, the optimal reaction conditions and reaction system were screened according to the Ct value, fluorescence intensity, and shape of amplification curve and was evaluated for sensitivity, reproducibility, and specificity. Meanwhile, the possibility of practical application of the method was explored by testing 172 clinical samples and 256 municipal wastewater samples. Results:A qRT-PCR assay for N_sgRNA in SARS-CoV-2 was initially established. The detection limit of the assay was 20 copies/mL, and the variation coefficients of in-batch (0.002%~0.767%) and batch to batch repetition (0.016%~0.752%) were less than 1%. Only N_sgRNA recombinant plasmid was detected in the specificity assay. So the method is more highly sensitive, specific and reproducible. The RatiosgRNA/ gRNA of clinical samples HK.3, EG.5.1, JN.1 and their sub-lineages and their corresponding urban sewage samples in epidemic period were significantly different ( P<0.05). There is a strong correlation between the median of RatiosgRNA/ gRNA in clinical samples and sewage samples in the same period (correlation coefficient r=1.000, P=0.010). Conclusions:In this study, a qRT-PCR method for detecting N_sgRNA of SARS-CoV-2 was established and the method has the characteristics of higher sensitivity, stronger specificity and better repeatability, and it can be used to detect SARS-CoV-2 infectivity.
9.Effect of Yiqi Wenyang Huoxue Lishui Components on Cardiac Function and Mitochondrial Energy Metabolism in CHF Rats
Hui GAO ; Zeqi YANG ; Xin LIU ; Fan GAO ; Yangyang HAN ; Aiyangzi LU ; Xingchao LIU ; Qiuhong GUO
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(2):27-36
ObjectiveTo investigate the effects of Yiqi Wenyang Huoxue Lishui components on the cardiac function and mitochondrial energy metabolism in the rat model of chronic heart failure (CHF) and explore the underlying mechanism. MethodsThe rat model of CHF was prepared by transverse aortic constriction (TAC). Eight of the 50 SD rats were randomly selected as the sham group, and the remaining 42 underwent TAC surgery. The 24 SD rats successfully modeled were randomized into model, trimetazidine (6.3 mg·kg-1), and Yiqi Wenyang Huoxue Lishui components (60 mg·kg-1 total saponins of Astragali Radix, 10 mg·kg-1 total phenolic acids of Salviae Miltiorrhizae Radix et Rhizoma, 190 mg·kg-1 aqueous extract of Lepidii Semen, and 100 mg·kg-1 cinnamaldehyde) groups. The rats were administrated with corresponding agents by gavage, and those in the sham and model groups were administrated with the same amount of normal saline at a dose of 10 mL·kg-1 for 8 weeks. Echocardiography was used to examine the cardiac function in rats. Enzyme-linked immunosorbent assay was employed to determine the serum levels of N-terminal pro-B-type natriuretic peptide (NT-ProBNP), hypersensitive troponin(cTnI), creatine kinase (CK), lactate dehydrogenase (LD), free fatty acids (FFA), superoxide dismutase (SOD), and malondialdehyde (MDA). The colorimetric assay was employed to measure the levels of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) in the myocardial tissue. The pathological changes in the myocardial tissue were observed by hematoxylin-eosin staining and Masson staining. The Na+-K+-ATPase and Ca2+-Mg2+-ATPase activities in the myocardial tissue were determined by the colorimetric assay. The ultrastructural changes of myocardial mitochondria were observed by transmission electron microscopy. Western blot was employed to determine the protein levels of ATP synthase subunit delta (ATP5D), glucose transporter 4 (GLUT4), and carnitine palmitoyltransferase-1 (CPT-1). The mitochondrial complex assay kits were used to determine the activities of mitochondrial complexes Ⅰ, Ⅱ, Ⅲ, and Ⅳ. ResultsCompared with the sham group, the model group showed a loosening arrangement of cardiac fibers, fracture and necrosis of partial cardiac fibers, inflammatory cells in necrotic areas, massive blue fibrotic tissue in the myocardial interstitium, increased collagen fiber area and myocardial fibrosis, destroyed mitochondria, myofibril disarrangement, sparse myofilaments, and fractured and reduced cristae. In addition, the rats in the model group showed declined ejection fraction (EF) and fractional shortening (FS), risen left ventricular end-diastolic diameter (LVIDd), left ventricular end-systolic diameter (LVIDs), left ventricular end-diastolic posterior wall thickness (LVPWd), left ventricular end-systolic posterior wall thickness (LVPWs), left ventricular end-diastolic volume (LVVOLd), and left ventricular end-systolic volume (LVVOLs), elevated levels of NT-ProBNP, cTnI, CK, MDA, FFA, and LD, lowered level of SOD, down-regulated protein levels of GLUT4 and CPT-1, decreased activities of Na+-K+-ATPase, Ca2+-Mg2+-ATPase, and respiratory complexes Ⅰ-Ⅳ, and declined levels of ATP5D, ATP, ADP, and AMP (P<0.05, P<0.01). Compared with the model group, the Yiqi Wenyang Huoxue Lishui components and trimetazidine groups showed alleviated pathological damage of the mitochondria and mycardial tissue, risen EF and FS, declined LVIDd, LVIDs, LVPWd, LVPWs, LVVOLd, and LVVOLs, lowered levels of NT-ProBNP, cTnI, CK, MDA, FFA, and LD, elevated level of SOD, up-regulated protein levels of GLUT4 and CPT-1, increased activities of Na+-K+-ATPase, Ca2+-Mg2+-ATPase, and respiratory complexes Ⅰ-Ⅳ, and elevated levels of ATP5D, ATP, ADP, and AMP (P<0.05, P<0.01). ConclusionYiqi Wenyang Huoxue Lishui components can improve the cardiac function, reduce myocardial injury, regulate glucose and lipid metabolism, optimize the utilization of substrates, and alleviate the damage of mitochondrial structure and function, thus improving the energy metabolism of the myocardium in the rat model of CHF.
10.Genetic diversity analysis of oxacillinase in 241 clinical isolates of Pseudomonas aeruginosa
Yuelong LI ; Jingyi ZHANG ; Yubing FU ; Meiqing SUN ; Beibei MIAO ; Xinyi GONG ; Xiao HAN ; Huan XING ; Pengfang GAO ; Jiachen LI ; Yating TANG ; Xinya FAN ; Yanlei GE ; Haijian ZHOU ; Juan LI ; Aiying DONG
Chinese Journal of Preventive Medicine 2025;59(7):1004-1012
Objective:To analyze the carriage status, subtype distribution and flanking gene sequence characteristics of oxacillinases (OXA enzyme) in 241 clinical strains of Pseudomonas aeruginosa, and assess their roles in the drug resistance of Pseudomonas aeruginosa and ability to horizontally transfer across species. Methods:Clinical P. aeruginosa isolates were collected from four hospitals in Sanya, Tangshan, Zhangjiakou, and Beijing. The prevalence of oxacillinases and their flanking gene sequences was analyzed by whole-genome sequencing (NGS) and bioinformatic approaches. Results:A total of 241 isolates of P. aeruginosa were gathered, and 35 blaOXA subtypes were identified through screening of 252 blaOXA genes. These genes were classified into three subfamilies: blaOXA-50-like (241, 95.6%), blaOXA-1-like (9, 3.6%) and blaOXA-10-like (2, 0.8%). Among these, 11 subtypes (11, 31.4%) were novel blaOXA subtypes. Nine of these belonged to the blaOXA-50-like subfamily and were designated as blaOXA-1244, blaOXA-1245, blaOXA-1246, blaOXA-1250, blaOXA-1252, blaOXA-1253, blaOXA-1254, blaOXA-1255, and blaOXA-1256. The remaining two belonged to the blaOXA-10-like subfamily and were named blaOXA-1247 and blaOXA-1248. Compared to the amino acid sequence of OXA-10, the newly identified subtype OXA-1247 exhibited a mutation at position 117, where a valine was replaced by a leucine. This change was thought to improve the enzyme′s ability to hydrolyze carbapenems. In the analysis of the flanking sequences of the blaOXA genes, Class I integrons were identified in four bacterial strains. The variable regions of these integrons carried three distinct patterns of resistance gene cassettes: aac( 6′) -Ib-blaOXA-1247-ant( 3′′) -Ia, aac( 6′) -Ib-blaOXA-1248 and aac( 6′) -Ib- blaIMP-45-blaOXA-1-catB3. Among these, the strain BJ2326 carried a class I integron that was connected to the downstream IS CR1 element to form a composite class I integron structure, additionally carrying the resistance gene blaPER-1. Out of the 223 non-wild-type P. aeruginosa strains, 127 strains exhibited non-wild-type profiles to the four beta-lactam antibiotics MEM, CAZ, FEP, and TZP, with the combination of MEM+CAZ+FEP being the most prevalent, representing 57.0% of the total. Conclusions:The blaOXA genes in 241 clinical P. aeruginosa strains showed diversity. Some blaOXA genes had a co-transfer risk with the metallo-β-lactamase resistance gene blaIMP-45. Among the 11 newly discovered blaOXA subtypes, the new subtype OXA-1247 may have carbapenemase activity and potential for horizontal transfer.

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