ObjectiveTo investigate the effect of Danggui Shaoyaosan on the expression of Toll-like receptor 4/nuclear factor-kappa B p65/NOD-like receptor protein 3 （TLR4/NF-κB p65/NLRP3） signaling pathway in the renal tissues of db/db mice with spontaneous diabetes， and to explore the potential mechanism by which Danggui Shaoyaosan alleviates inflammation in diabetic kidney disease （DKD）. MethodsThirty db/db mice were divided into five groups： A model group， Danggui Shaoyaosan low- （16.77 g·kg^-1·d^-1）， medium- （33.54 g·kg^-1·d^-1）， and high-dose （67.08 g·kg^-1·d^-1） intervention groups， as well as an irbesartan group （0.025 g·kg^-1·d^-1） by the random number table method， with 6 mice in each group. Additionally， 6 db/m mice were assigned to the normal group. After 8 weeks of intervention， the following parameters were determined by corresponding methods： body weight， fasting blood glucose （FBG）， 24-hour urinary protein （24 h-UTP）， and serum creatinine （SCr） levels， renal histopathological analysis by hematoxylin-eosin （HE） staining， Masson staining， and periodic acid-Schiff （PAS） staining， the protein and mRNA expression levels of TLR4， NF-κB p65， NLRP3， tumor necrosis factor-alpha （TNF-α）， interleukin-1β （IL-1β）， interleukin-6 （IL-6）， interleukin-10 （IL-10）， and interleukin-18 （IL-18） by Western blot and Real-time quantitative polymerase chain reaction （Real-time PCR）， as well as TLR4， NF-κB p65， and NLRP3 protein expression in renal tissues by immunohistochemistry （IHC）. ResultsCompared with the normal group， the model group exhibited increased body weight， FBG， 24 h-UTP， and SCr levels （P<0.05）； disordered renal structure， thickened basement membrane， and interstitial inflammatory cell infiltration， elevated TLR4， NF-κB p65， NLRP3， TNF-α， IL-1β， IL-6， and IL-18 expression； as well as decreased IL-10 expression （P<0.05）. Compared with the model group， these pathological changes and biochemical abnormalities were reversed in the medicine intervention groups to varying degrees （P<0.05）. ConclusionDanggui Shaoyaosan may delay DKD progression by alleviating renal inflammatory response and reducing urinary protein excretion via modulating the TLR4/NF-κB p65/NLRP3 signaling pathway.

OBJECTIVE To investigate the improvement effects and mechanism of Achyranthes bidentata total saponins （ABS） extract on vascular endothelial dysfunction in spontaneously hypertensive rat （SHR） based on cytochrome P450 4A （CYP4A）/20-hydroxyeicosatetetraenoic acid （20-HETE）/G protein-coupled receptor 75 （GPR75） axis. METHODS Ten Wistar- Kyoto rats were taken as the normal control group. Forty SHR were first stratified by systolic blood pressure and then， within each stratum， randomly assigned using a random-number table to the model group （MOD group）， captopril positive control group （CAP group， 10 mg/kg）， ABS low- and high-dose extract groups （ABS-L group， ABS-H group， 60 and 120 mg/kg）， with 10 rats in each group. Animals in each group were given the corresponding drug or equal volume of pure water by gavage， once a day， for 28 consecutive days. After the last administration， systolic blood pressure of rats was measured. The levels of vasoactive substances， inflammatory factors and oxidative stress indicators in serum were measured. The pathological changes of rat thoracic aorta were observed. The level of reactive oxygen species （ROS） in aortic tissue was analyzed. The expressions of endothelial nitric oxide synthase （eNOS）， CYP4A， GPR75， nuclear factor-κB p65 （NF-κB p65）， phosphorylated NF-κB p65， p22phox， and reduced nicotinamide adenine dinucleotide phosphate oxidase 4（NOX4） in thoracic aorta tissue were detected. RESULTS After 28 d of treatment， compared with MOD group， the systolic blood pressure of rats in the ABS-L and ABS-H groups decreased significantly. The levels of 20-HETE， angiotensin Ⅱ， interleukin-1β， interleukin-6， tumor necrosis factor-α， intercellular cell adhesion molecule-1 and malondialdehyde in serum were significantly reduced （P＜0.05 or P＜0.01）， while the levels of nitric oxide， superoxide dismutase， glutathione peroxidase and catalase were significantly increased （P＜0.05 or P＜0.01）. Intimal damage of thoracic aorta was reduced， and endothelial cell morphology was improved. The expressions of ROS， CYP4A， GPR75， p22phox， NOX4 and the phosphorylation level of NF-κB p65 protein in thoracic aorta were down-regulated or reduced （P＜0.05 or P＜0.01）， while the expression of eNOS was up-regulated （P＜0.05 or P＜0.01）. CONCLUSIONS ABS extract may alleviate the inflammatory response and oxidative stress in SHR effectively by down-regulating the expression of CYP4A， reducing the production of 20-HETE， inhibiting the activation of GPR75， and subsequently suppressing the activation of downstream NF-κB and NOX4， thereby improving hypertension-related vascular endothelial dysfunction.

Objective To prepare the recombinant Echinococcus granulosus Polo-like kinase 2 (rEgPLK2) protein and evaluate its immunoprotective efficacy against cystic echinococcosis, so as to provide insights into research and development of novel vaccines against echinococcosis. Methods The Polo-like kinase (PLK) protein sequences were retrieved from 12 species in the NCBI protein database, including E. granulosus and E. multilocularis. Multiple sequence alignment was performed using the Clustal Omega program, and structural visualization and homology analysis were conducted using the ESPript 3.2 program. The recombinant plasmid pET-30a-EgPLK2 was transformed into BL21(DE3) competent cells. Protein expression was induced with isopropyl-β-D-thiogalactoside (IPTG), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to characterize the expression and molecular weight of the rEgPLK2 protein. The purified rEgPLK2 protein was thoroughly emulsified with Freund’s complete adjuvant at a 1 : 1 volume ratio. Two New Zealand white rabbits were immunized with multipoint subcutaneous injection on the back at a dose of 300 μg per rabbit for primary immunization. For booster immunizations, the protein was emulsified with Freund’s incomplete adjuvant at a 1 : 1 volume ratio and administered on days 14, 28, and 42 after the primary immunization at a dose of 150 μg per rabbit. Serum was sampled from the rabbit ear vein on day 7 after the final immunization to yield anti-rEgPLK2 polyclonal antibodies. Antibody titer was determined by indirect enzyme-linked immunosorbent assay (ELISA), and antibody specificity was verified by Western blotting. The tissue localization of the EgPLK2 protein was detected in E. granulosus protoscoleces and adult worms using immunofluorescence assay (IFA). Eighteen 6- to 8-week-old female SPF-grade BALB/c mice were randomly divided into three groups, including the blank control group, rEgPLK2-ISA immunization group, and PBS-ISA adjuvant control group, of 6 mice each group. Mice in the rEgPLK2-ISA immunization group and PBSISA group received three primary immunizations via intramuscular injection, and animals in the rEgPLK2-ISA immunization group was inoculated with immunogens prepared by emulsifying rEgPLK2 protein with ISA 201 adjuvant at a 1 : 1 volume ratio (6 μg per mouse), while mice in the PBS-ISA adjuvant control group received an equal volume of PBS emulsified with ISA adjuvant at a 1 : 1 volume ratio. A fourth booster immunization was administered via intraperitoneal injection. Mice in the rEgPLK2-ISA immunization group received a booster immunization with 8 μg of rEgPLK2 protein per mouse, and animals in the PBS-ISA group received an equal volume of PBS, with immunizations given at 2-week intervals. Mice in the blank control group were given no treatment, and housed under standard conditions. Tail vein blood was collected from all mice 7 days after the final immunization, and levels of specific anti-rEgPLK2 IgG antibody and its subclasses (IgG1, IgG2a, IgG2b, IgG3) were measured by indirect ELISA. E. granulosus infection was modelled in mice through injection with 1 000 E. granulosus protoscoleces via intrahepatic portal vein in the rEgPLK2-ISA immunization group and PBS-ISA adjuvant control group 2 weeks after the last immunization. All mice were sacrificed and dissected. The number of cysts was counted in mouse livers, and the cyst reduction rate was calculated. Liver tissues were processed for paraffin sectioning and stained with hematoxylin and eosin (HE), and histopathological changes were examined under a light microscope. Results Sequence analysis revealed that EgPLK2 shared a high amino acid sequence homology with E. multilocularis PLK2 (EmPLK2) and contained the typical domains of the Polo-like kinase family, including the serine/threonine protein kinase catalytic domain (STKc) and Polo-box. The IPTG-induced rEgPLK2 protein was mainly expressed in the form of inclusion bodies, and the purified rEgPLK2 protein showed a relative molecular mass of approximately 70 kDa. The prepared rabbit anti-rEgPLK2 polyclonal antibody had a titer of 1 : 256 000, and Western blotting assay showed that this anti-body specifically recognized the rEgPLK2 protein with a relative molecular mass of approximately 70 kDa. Immunofluorescence assay showed that the EgPLK2 protein was localized in the excretory bladder and rostellum of E. granulosus protoscoleces, as well as the tegument, suckers, and inter-proglottid junctions of adult worms. Immunoprotective assay showed that the serum levels of specific anti-rEgPLK2 IgG, IgG1, IgG2a, and IgG2b antibodies were 2.92 ± 0.49, 0.33 ± 0.10, 0.31 (0.36), and 3.12 (1.73) in mice in the rEgPLK2-ISA immunization group, which were all significantly higher than those in the PBS-ISA adjuvant control group (0.14 ± 0.04, 0.07 ± 0.01, 0.12 ± 0.04, and 0.11 ± 0.04, respectively) (t = 19.28 and 8.46, Z = 3.75 and 4.15; all P values < 0.001); however, there was no significant difference in the serum anti-IgG3 antibody level between the rEgPLK2-ISA immunization group and the PBS-ISA adjuvant control group [0.07 (0.01) vs. 0.073 (0.07); Z = 0.69, P > 0.05)]. In the mouse model of E. granulosus infections, the area of hepatic lesions was reduced and the inflammatory infiltration was alleviated in the rEgPLK2-ISA immunization group than in the PBS-ISA adjuvant control group, and the number of hepatic cysts was higher in the PBS-ISA adjuvant control group than in the rEgPLK2-ISA immunization group [8.00 (2.00) vs. 1.00 (0.75); Z = −2.93, P < 0.01], with a cyst reduction rate of 80.40%. Indirect ELISA assay measured higher serum levels of specific anti-rEgPLK2 IgG (3.28 ± 0.48 vs. 0.11 ± 0.04; t = 15.86, P < 0.01), IgG1 (0.29 ± 0.02 vs. 0.09 ± 0.01; t = 15.67, P < 0.01), IgG2a [3.71 (1.09) vs. 0.08 (0.03); Z = 2.88, P < 0.01], and IgG2b antibodies [3.34 (1.01) vs. 0.08 (0.03); Z = 2.88, P < 0.01] in the rEgPLK2-ISA immunization group than in the PBS-ISA adjuvant control group, and there was no significant difference in the serum level of the specific anti-rEgPLK2 IgG3 antibody between the rEgPLK2-ISA immunization group and the PBS-ISA adjuvant control group (0.07 ± 0.01 vs. 0.07 ± 0.01; t = 1.29, P > 0.05). Conclusions The prokaryotic expression system has been successfully constructed for the EgPLK2 gene and the anti-rEgPLK2 polyclonal antibody has been obtained. The rEgPLK2 protein exhibits a high immunogenicity, and is effective to protect against E. granulosus infection, and inhibits cyst development, which is a promising candidate vaccine target against cystic echinococcosis.

Objective To evaluate the clinical efficacy and safety of sulbactam-durlobactam in the treatment of pulmonary infection caused by extensively drug-resistant Acinetobacter baumannii (XDR-AB) after liver transplantation. Methods A retrospective analysis was performed on the data of 3 liver transplant recipients admitted to the First Affiliated Hospital of Xi'an Jiaotong University from May to December 2025, who developed postoperative XDR-AB pulmonary infection and received sulbactam-durlobactam-based anti-infective therapy. Clinical data, clinical efficacy, microbiological response, safety and outcomes were analyzed. Results All isolated strains were XDR-AB producing OXA-23 carbapenemase, and in vitro antimicrobial susceptibility testing showed sensitivity to sulbactam-durlobactam. After treatment with sulbactam-durlobactam, all 3 recipients achieved clinical cure and microbiological eradication, with a treatment course of 6-8 days and pathogen clearance time of 3-6 days. Septic shock was effectively controlled in all recipients, who were successfully weaned from mechanical ventilation, and oxygenation index and organ function scores were significantly improved. No definite nephrotoxicity or other severe adverse reactions related to sulbactam-durlobactam were observed during treatment, and the 30-day all-cause fatality was 0. Two critically ill recipients achieved rapid microbiological clearance after combined nebulized phage therapy. Conclusions Sulbactam-durlobactam-based regimen shows favorable efficacy and safety in liver transplant recipients with postoperative XDR-AB pulmonary infection, and has a promising clinical application prospect.

OBJECTIVE To study the mechanism of action of Rehmannia glutinosa-medicated serum （RG） in regulating lipopolysaccharide （LPS）-induced polarization of BV2 microglia to interfere with neuroinflammation. METHODS An in vitro neuroinflammation model of BV2 cells induced by LPS was established. Cells were divided into control group， LPS group， 10%RG group， 20%RG group， BAY 11-7082 [nuclear factor kappa B （NF-κB） inhibitor] group， and 20%RG+BAY 11-7082 group. Except for the control group， cells in all other groups were pretreated with corresponding drugs for 12 h and then stimulated with LPS for 24 h. The morphology of cells in each group was observed， and the fluorescence intensity of ionized calcium binding adaptor molecule 1 （Iba-1）， inducible nitric oxide synthase （iNOS）， CD206， the mRNA expression of tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6）， IL-1β， iNOS， IL-4， IL-10， transforming growth factor-β （TGF-β）， arginase-1 （Arg-1）， and the Toll-like receptor 4 （TLR4）/NF-κB/NOD-like receptor thermal protein domain associated protein 3 （NLRP3） signaling pathway-related protein expression were detected. RESULTS Compared with the control group， the LPS group showed significant changes in cell morphology， exhibiting a typical M1 activated morphology. The fluorescence intensity of Iba-1 and iNOS， the relative expression levels of TNF-α， IL-6， IL-1β， iNOS mRNA， the relative expression levels of TLR4， NLRP3， caspase-1 p20， IL-1β p17 protein， and the phosphorylation levels of NF-κB p65 and inhibitor of nuclear factor kappa B α were significantly increased （P＜0.05）. The fluorescence intensity of CD206 and the relative expression levels of IL-4， IL-10， TGF-β， and Arg-1 mRNA were significantly reduced （P＜0.05）. Compared with the LPS group， the changes in the above indicators in the cells of the 10%RG group， 20%RG group， BAY 11-7082 group， and 20%RG+BAY 11-7082 group were significantly reversed （P＜0.05）， and there was no statistically significant difference in the comparison of the last three groups （P＞0.05）. CONCLUSIONS RG can effectively inhibit the overall activation of microglia and correct their M1/M2 polarization imbalance， and its mechanism may be closely related to the inhibition of excessive activation of the TLR4/NF-κB/NLRP3 signaling pathway.

This paper interprets the best practice guidelines for Practice Education in Nursing published by the Registered Nurses' Association of Ontario (RNAO), providing a scientific basis and insights for the development and progress of nursing students' practical education in China. The goal is to improve the quality of nursing students' clinical practice and enhance their clinical service capabilities.

Objectives:To investigate the clinical value of cardiac magnetic resonance imaging(CMR)feature-tracking strain analysis in risk stratification of diabetic heart failure with preserved ejection fraction(HFpEF).Methods:In this retrospective study,a total of 215 patients with diabetic HFpEF who underwent CMR at Chinese Academy of Medical Sciences Fuwai Hospital from January 2012 to December 2018 were included.Myocardial strain parameters were calculated using CMR feature-tracking technology.Patients were followed up by medical records or telephone calls.Composite endpoint event,all-cause death or heart failure hospitalization during follow-up were recorded.Patients were divided into event group and event-free group.Univariable and multivariable Cox proportional hazard regression analyses were performed to determine the risk factors for the outcomes in diabetic HFpEF.The effects of hypertension and obesity on the prognosis of diabetic HFpEF patients and whether they affect the prognostic value of CMR feature-tracking strain analysis were also analyzed.Results:During a follow-up of(7.1±1.8)years,93(43.3%)patients had endpoint events(event group),including 28 all-cause deaths and 65 heart failure hospitalization.Compared with the event-free group(n=122),patients in the event group had significantly lower left ventricular ejection fraction,higher prevalence and extent of late gadolinium enhancement,and significantly reduced global longitudinal strain(GLS),global circumferential strain,global radial strain,and global systolic longitudinal strain rate(all P<0.05).The absolute GLS value was significantly lower in event group than in event-free group,regardless of the presence of hypertension and obesity.Multivariate Cox regression analysis showed that estimated glomerular filtration rate(HR=0.983,95%CI:0.972-0.993,P=0.001),left atrial volume index(HR=1.015,95%CI:1.005-1.026,P=0.004),and GLS(HR=1.142,95%CI:1.060-1.231,P<0.001)were independent risk factors for adverse cardiovascular events in diabetic HFpEF patients.However,adjusted N-terminal pro-brain natriuretic peptide was not an independent prognostic factor.The cut-offvalue of GLS to predict outcome was-14.09%from ROC curve analysis.The Kaplan-Meier curve showed that in patients with and without hypertension and obesity,patients with the GLS>-14.09%had lower event-free survival compared to patients with GLS≤-14.09%(all P<0.05),and the ability of GLS to predict adverse outcomes was not affected by hypertension and obesity.Conclusions:GLS obtained by CMR feature-tracking strain analysis is an independent predictor of adverse outcomes in diabetic HFpEF,and its ability to predict adverse outcomes is independent of hypertension and obesity.

Objective To compare the success rate and stability of rat models of comorbid chronic pain and depression induced by different doses of complete Freund's adjuvant(CFA).Methods Sixty SD rats were divided randomly into a control group,low-dose CFA group(CFA-L),and high-dose CFA group(CFA-H)(n=20 rats per group).Rats in the CFA-L and CFA-H groups were injected with 50 and 100 μL CFA,respectively,and rats in the control group were injected with 0.9％sodium chloride solution.The general state,body weight,mechanical withdrawal threshold(MWT),and thermal withdrawal latency(TWL)were observed at 0,7,14,21,and 28 days after modeling.Depressive behavior was evaluated using the open field test(OFT),forced swim test(FST),and tail suspension test(TST).Glutamate(Glu)and γ-aminobutyric acid(GABA)levels in the anterior cingulate cortex were detected by enzyme-linked immunosorbent assay.Brain-derived neurotrophic factor(BDNF)expression in the anterior cingulate cortex was detected by immunohistochemistry,and pathological changes in the anterior cingulate cortex were observed by HE staining.Results(1)Regarding the general condition of the rats,the left ankle joint and toes were obviously red and swollen in the CFA-L and CFA-H groups on the 7th day after modeling,and the swelling was more severe in the CFA-H group.The redness and swelling of the left hind foot and ankle joint and toes gradually recovered in the CFA-L group on days 14,21,and 28 after modeling,but were still obvious in the CFA-H group,and the water and food intake decreased.(2)The body mass was significantly lower in rats in the CFA-H group compared with those in the blank and CFA-L groups on days 14,21,and 28 after modeling(P＜0.05,P＜0.05).(3)Regarding pain-related behavior,the MWT and TWL were significantly decreased in the CFA-L and CFA-H groups on the 7th and 14th days after modeling,compared with the control group(P＜0.05,P＜0.05).On day 21 after modeling,MWT was significantly lower in the CFA-H group than in the blank and CFA-L groups(P＜0.05,P＜0.05),and TWL was significantly lower in the CFA-L and CFA-H groups than in the blank group(P＜0.05,P＜0.05).On day 28 after modeling,MWT and TWL were significantly lower in the CFA-H group than in the blank and CFA-L groups(P＜0.05,P＜0.05).(4)In terms of depression-related behaviors,the total OFT movement distance was significantly lower in the CFA-H group than in the blank and CFA-L groups on day 7 after modeling(P＜0.05,P＜0.05).The total OFT distance and central dwell time were significantly lower in the CFA-H group than in the blank and CFA-L groups on days 14,21,and 28 after modeling(P＜0.05,P＜0.05),and the result in the FST and TST were significantly higher than in the blank and CFA-L groups(P＜0.05,P＜0.05).(5)Glu,GABA,and BDNF expression levels were significantly higher in the CFA-H group than in the blank and CFA-L groups(P＜0.05,P＜0.05),while GABA,Glu/GABA,and BDNF levels were significantly lower in the CFA-H group than in the blank and CFA-L groups(P＜0.05,P＜0.05,P＜0.05).(6)The CFA-L group showed less damage in the anterior cingulate cortex,more pyramidal cells,more arranged cells,clear nucleoli,and a small number of cells with karyokynesis and deep staining.Compared with the CFA-L group,rats in the CFA-H group showed a disordered cell arrangement in the injured area of the anterior cingulate cortex,a large number of pyknotic and hyperchromatic neurons,significantly fewer or absent pyramidal cells,and vacuoles,red blood cells,and neurofibrillary tangles in the interstitial space.Conclusions Injection of CFA 100 μL can be used to establish a rat model of chronic inflammatory pain and depression,showing hyperalgesia,depression-like behavioral changes,changes in levels of Glu,GABA,and BDNF in the anterior cingulate cortex,and pathological changes in the anterior cingulate cortex,consistent with the pathophysiological characteristics of chronic pain and depression.

Objectives:To investigate the clinical value of cardiac magnetic resonance imaging(CMR)feature-tracking strain analysis in risk stratification of diabetic heart failure with preserved ejection fraction(HFpEF).Methods:In this retrospective study,a total of 215 patients with diabetic HFpEF who underwent CMR at Chinese Academy of Medical Sciences Fuwai Hospital from January 2012 to December 2018 were included.Myocardial strain parameters were calculated using CMR feature-tracking technology.Patients were followed up by medical records or telephone calls.Composite endpoint event,all-cause death or heart failure hospitalization during follow-up were recorded.Patients were divided into event group and event-free group.Univariable and multivariable Cox proportional hazard regression analyses were performed to determine the risk factors for the outcomes in diabetic HFpEF.The effects of hypertension and obesity on the prognosis of diabetic HFpEF patients and whether they affect the prognostic value of CMR feature-tracking strain analysis were also analyzed.Results:During a follow-up of(7.1±1.8)years,93(43.3%)patients had endpoint events(event group),including 28 all-cause deaths and 65 heart failure hospitalization.Compared with the event-free group(n=122),patients in the event group had significantly lower left ventricular ejection fraction,higher prevalence and extent of late gadolinium enhancement,and significantly reduced global longitudinal strain(GLS),global circumferential strain,global radial strain,and global systolic longitudinal strain rate(all P<0.05).The absolute GLS value was significantly lower in event group than in event-free group,regardless of the presence of hypertension and obesity.Multivariate Cox regression analysis showed that estimated glomerular filtration rate(HR=0.983,95%CI:0.972-0.993,P=0.001),left atrial volume index(HR=1.015,95%CI:1.005-1.026,P=0.004),and GLS(HR=1.142,95%CI:1.060-1.231,P<0.001)were independent risk factors for adverse cardiovascular events in diabetic HFpEF patients.However,adjusted N-terminal pro-brain natriuretic peptide was not an independent prognostic factor.The cut-offvalue of GLS to predict outcome was-14.09%from ROC curve analysis.The Kaplan-Meier curve showed that in patients with and without hypertension and obesity,patients with the GLS>-14.09%had lower event-free survival compared to patients with GLS≤-14.09%(all P<0.05),and the ability of GLS to predict adverse outcomes was not affected by hypertension and obesity.Conclusions:GLS obtained by CMR feature-tracking strain analysis is an independent predictor of adverse outcomes in diabetic HFpEF,and its ability to predict adverse outcomes is independent of hypertension and obesity.

Objective:To explore the relationship between 23S rRNA domain V locus mutations in mycoplasma pneumoniae (MP) and the clinical characteristics plus macrolide resistance in pediatric MP pneumonia.Methods:A retrospective analysis was conducted on 220 children with MP pneumonia admitted to the Xi′an Central Hospital from January 2021 to June 2024. Patients were divided into a mutation group and a non-mutation group according to the presence or absence of point mutations at positions 2063, 2064, 2067 and 2617 within the 23S rRNA domain V. General data, clinical features [disease course, fever duration, length of hospital stay, time to resolution of chest X-ray infiltrates, pleural effusion, pulmonary parenchymal lesions, white blood cell count (WBC), lactate dehydrogenase (LDH), MP-DNA load] and macrolide resistance were compared between the two groups.Results:Among the 220 enrolled patients, 114 were assigned to the mutation group and 106 to the non-mutation group. Mutations detected in the 23S rRNA domain V were A2063 ( n=107), C2617 ( n=2), A2064 ( n=2) and A2067 ( n=0); three patients had combined A2063+ A2064 mutations. The proportion of severe pneumonia was higher in the mutation group ( P<0.05). Compared with the non-mutation group, the mutation group exhibited longer disease course, fever duration, hospital stay and time to resolution of chest X-ray infiltrates; higher rates of pleural effusion; and higher LDH levels and MP-DNA loads (all P<0.05). Both groups showed the highest resistance to first-generation macrolides (erythromycin, erythromycin ethylsuccinate, erythromycin stearate) and the highest sensitivity to third-generation macrolides (telithromycin, josamycin). Resistance rates to first-and second-generation macrolides were significantly higher in the mutation group (all P<0.05). Conclusions:Mutations in the 23S rRNA domain V of MP are closely associated with clinical severity in pediatric MP pneumonia, and patients harboring these mutations display higher rates of macrolide resistance.