1.Inverse Association Between Alcohol Consumption and Parkinson’s Disease Risk and Identification of RIT2 as a Linked Biomarker
Wei LU ; Xiu-Li CHENG ; Xiao-Yun PAN ; Dan-Dan YANG ; Hui-Ling ZOU ; Li-Guo DONG ; Yi-Liang WEI ; Gui-Yun CUI
Progress in Biochemistry and Biophysics 2026;53(6):1723-1733
ObjectiveAs a common lifestyle habit, alcohol consumption has a controversial association with the onset of Parkinson’s disease (PD). To demonstrate the correlation between alcohol consumption and PD and to identify associated genes, we integrated findings from clinical surveys, genomics, transcriptomics, and animal experiments. MethodsWe investigated the alcohol consumption rates (including both before and after disease onset) among 244 PD patients in China and 177 PD patients from the U.S. NHANES database. Mendelian randomization (MR) analysis was performed using genome-wide association study (GWAS) data for three alcohol-related traits and seven PD-related datasets from the MRC IEU OpenGWAS database. Transcriptomic data from the substantia nigra of PD patients were obtained from three GEO datasets (GSE7621, GSE20141, and GSE49036) to analyze RIT2 gene transcription. Finally, three groups of animal experiments (water/20% ethanol/20% liquor, with 4 C57BL/6J mice per group) were conducted to examine changes in brain RIT2 gene expression and transcriptomic profiles following alcohol consumption. ResultsThe alcohol consumption rates among PD patients in China and the U.S. (9%-18.87%) were significantly lower than the general population rates of 15%-45% in their respective regions (P<0.001), suggesting a possible negative association between alcohol consumption and PD. Subsequently, in 21 bidirectional MR analyses using 3 alcohol-related GWAS datasets and 7 PD-related GWAS datasets, the forward MR analyses (alcohol intake as exposure, PD as outcome) yielded 12 negative associations (ORIVW<1) and 9 positive associations (ORIVW>1). Among these, only two negative associations reached statistical significance: alcohol intake frequency (ORIVW=0.75, 95% CI: 0.60-0.93, P=0.010) and alcohol consumption (ORIVW=0.20, 95% CI: 0.05-0.83, P=0.026). The forward MR analysis (alcohol intake→PD) identified 235 SNPs, annotated to 316 genes, while the reverse MR analyses (PD→alcohol intake) identified 37 SNPs, annotated to 53 genes. Notably, only the RIT2 gene appeared in both the forward and reverse MR analyses (alcohol intake→PD: rs28597806, rs8083110; PD→alcohol intake: rs4588066). RIT2 is selectively expressed in the human brain (FPKM: 5.259±2.103), with low or no expression in peripheral tissues (FPKM: <1). Analysis of three human substantia nigra transcriptomic datasets revealed a decreasing trend in RIT2 gene expression in PD patients (GSE20141 array signal: 3.49±1.23 vs. 2.33±0.87, P=0.044). Animal experiments demonstrated that administration of 20% ethanol or 20% liquor (approximately 8% ethanol) stimulated a >2-fold upregulation of RIT2 gene expression in the mouse brain. Furthermore, transcriptomic sequencing revealed that the two alcohol-treated groups exhibited 96 (20% ethanol vs. water control) and 4 (20% liquor vs. water control) differentially expressed genes, respectively, indicating that low-dose alcohol consumption can achieve RIT2 upregulation while minimizing impact on other brain genes. In addition to its anti-infective effects, low-dose alcohol consumption primarily influences signaling pathways related to neurodegenerative diseases such as PD and Prion diseases. ConclusionAlcohol consumption is generally considered as a harmful lifestyle habit. However, some studies have also shown a lower risk of mortality among individuals who consume low doses of alcohol (100 g/week of ethanol) or drink occasionally. Currently, one of the research focuses on alcohol consumption is whether the human body can benefit from low-dose alcohol intake. This study provides new evidence supporting a negative association between alcohol consumption and PD, and for the first time, through MR analysis, identifies the RIT2 gene as a potential mediator of the effect of alcohol consumption on PD. RIT2 is selectively expressed in the human brain. Building upon existing evidence indicating downregulated RIT2 gene expression in PD pathogenesis, our experiments confirm that low-dose alcohol consumption can upregulate RIT2 expression in the brain. In brief, alcohol consumption may suppress the pathogenesis of PD by upregulating RIT2 expression in the substantia nigra. China is facing a serious problem of population aging. This study offers important insights for long-term PD prevention and treatment strategies, with the aim of benefiting more potential PD patients through lifestyle modifications, thereby improving the quality of life of the aging population and reducing the economic burden on healthcare.
2.Association of urine cadmium levels with thyroid hormone levels among middle-aged and older adults aged 40-89 years in selected areas of China
Changzi WU ; Xiaochen WANG ; Yue CHEN ; Zheng LI ; Yi ZHANG ; Yuan WEI ; Bing WU ; Wenli ZHANG ; Zhengxiong YANG ; Xiaojie DONG ; Ruiting HAO ; Xiu YE ; Luxi WEI ; Yingli QU ; Haiyan CHU ; Yuebin LYU ; Ying ZHU ; Dongqun XU ; Xiaoming SHI
Chinese Journal of Preventive Medicine 2025;59(2):209-215
Objective:To explore the relationship between urinary cadmium levels and thyroid hormone levels in people aged 40-89 years old in selected areas of China.Methods:Based on the "Investigation of the Impact of Soil Quality of Agricultural Land on Human Health in Typical Areas" project from October 2019 to August 2020, a multi-stage stratified random sampling method was used to include 6 588 middle-aged and older adults aged 40-89. Demographic characteristics, dietary frequency and disease status were collected through the questionnaire and physical examination. Urinary cadmium and urinary creatinine were detected by random midstream urine. Fasting venous blood was collected for the detection of Triiodothyronine (T3) and Thyroxine (T4). The linear mixed effects model was used to explore the association of urine cadmium levels with thyroid hormone levels. Its dose-response relationship was explored by using the restricted cubic spline.Results:The age of the subjects was (63.48±12.18) years, with males accounting for 51.28%. The M ( Q 1,Q 3) of urinary cadmium level, T3 and T4 was 2.48 (1.36, 4.42) μg/g·creatinine, (1.96±0.51) nmol/L and (113.75±29.11) nmol/L, respectively. The linear mixed effects model showed that the changes of T3 and T4 were 0.027 (0.009, 0.044) nmol/L and 2.019 (1.084, 2.953) nmol/L for each one-unit increase (natural logarithm transformed) of urinary cadmium. The restricted cubic spline showed that there was a positive nonlinear association between urinary cadmium and T3 as well as T4 (all Pnonlinear<0.05). Conclusion:In selected areas of China, the urinary cadmium level of middle-aged and older adults aged 40-89 years is positively associated with T3 and T4.
3.Predictive value of dose-surface histogram for acute radiation proctitis in prostate cancer patients following radiotherapy
Xin ZHAO ; Mei-Liu YANG ; Xiao-Hui HAO ; Tian-Xiong WEI ; Qi ZHANG ; Hao-Yu CHANG ; Xiu-Xia WU
Medical Journal of Chinese People's Liberation Army 2025;50(1):44-49
Objective To evaluate the predictive value of dose-surface histogram(DSH)for radiation proctitis(RP)in prostate cancer(PCa)patients undergoing radiotherapy.Methods This prospective randomized controlled clinical trial included 380 PCa patients who underwent image-guided radiotherapy in the First Affiliated Hospital of Hebei Northern University from January 2018 to January 2023.Patients were randomly divided into observation group(n=200)and control group(n=180).The rectal dose distribution of patients in the two groups was evaluated by using DSH and dose-volume histogram(DVH),respectively.The receiver operating characteristic(ROC)curve was utilized to evaluate the predictive value of DSH for acute RP,with DVH serving as a reference.Results The difference was not statistically significant in clinical information such as age,KPS score,and body mass index(BMI)between the observation and control groups(P>0.05),as well as in acute RP incidence(P>0.05).There were significant differences in S40 and V40,S50 and V50,S60 and V60,S70 and V70,and S78 and V78 between the two groups(P<0.05).S40,S50,V40,and V50 showed low efficacy(P<0.001)in predicting acute RP at each level,with AUC≤0.700.S60 and V60 showed moderate efficacy(P<0.001)in predicting acute RP at each level,with AUC 0.700-0.900.S70,S78,V70 and V78 showed high efficacy(P<0.001)in predicting acute RP at each level,with AUC>0.900.Conclusions The predictive value of DSH for rectal toxicity in patients with PCa is basically consistent with that of DVH.It is expected to become a novel and valuable tool for evaluating radiotherapy plans in the future.
4.Investigating the mechanism of Legionella pneumophila inhibiting endosome-lysosome fusion in mouse macrophages based on transcriptome sequencing
Min-Jia CHEN ; Xiu-Qin CAO ; Rui-Xia HE ; Hai-Xia CHEN ; Zhi-Wei YANG
Medical Journal of Chinese People's Liberation Army 2025;50(2):176-187
Objective To explore the pathogenic mechanisms of Legionella pneumophila(L.pneumophila)infection inhibiting the fusion of endosome-lysosome fusion in mouse macrophages.Methods Twelve C57 mice were randomly divided into control group and L.pneumophila infection group(n=6 each).After anesthesia,an equal volume of physiological saline or L.pneumophila solution was administered nasally.Body weight changes were monitored for 3 consecutive days,and the lungs were extracted to assess injury.Hematoxylin and eosin(HE)staining and immunohistochemical staining were performed to observe the pathological characteristics of lung tissue in both groups.Transcriptome sequencing was utilized to analyze differentially expressed genes(DEGs)and associated signaling pathways in lung tissues.Mouse bone marrow macrophages(BMDMs)were isolated and co-cultured with L.pneumophila,with infection status confirmed by immunofluorescence staining.Transcriptome sequencing was employed to analyze DEGs and enriched related signaling pathways before and after infection.Core genes involved in the post-infection signaling pathway were identified,and the consistency of their mRNA expression levels in vivo and in vitro was verified using RT-qPCR.The expression of relevant proteins was detected by Western Blotting,and bacterial proliferation assays were conducted to evaluate the intracellular replication of L.pneumophila.Results Compared with control group,the body weight of mice in L.pneumophila infection group significantly decreased(P<0.001)on the second and third day post-infection.Edema and red hepatoid degeneration were observed in both left and right lung tissues,with lesion areas spreading from the hilum to the lung periphery.HE staining revealed increased inflammatory cell infiltration in the alveolar spaces,thickening of alveolar septa and increased fibrin exudation in L.pneumophila infection group.Immunohistochemistry results showed a significant increase in myeloperoxidase(MPO)activity in the lung tissue infected mice(P<0.001).Transcriptome sequencing identified 2550 DEGs,with 1444 up-regulated genes and 1106 down-regulated genes.KEGG enrichment analysis indicated that these DEGs were mainly involved in pathways related to tumor necrosis factor,rheumatoid arthritis,Rap1,PI3K-Ak,and phagosome pathways.Immunofluorescence results showed in vitro proliferation of L.pneumophila within mouse BMDMs.Transcriptome sequencing identified 2550 DEGs,including 1677 up-regulated genes and 873 down-regulated genes.KEGG enrichment analysis showed that enrichment in pathway related to transcription dysregulation in cancer,PI3K-Akt and phagosome pathways.Thirteen core genes,including tubulin β1(Tubb1),were identified from the overlap between mouse lung tissue and BMDMs.RT-qPCR results demonstrated a significant decrease in Tubb1 expression in both lung tissue and BMDMs infected with L.pneumophila(P<0.001).Western Blotting results revealed significant decreases in Rab7,Tubb1,and LAMP2 protein expression(P<0.05),and increases in iNOS and MPO expression(P<0.05).Intracellular proliferation experiments indicated that L.pneumophila gradually increased within BMDMs over time.Conclusion The potential mechanism of L.pneumophila infection in mouse macrophages involves the down-regulation of Rab7/Tubb1/LAMP2 which inhibits the endosome-lysosome fusion.
5.Comparison of clinical characteristics between primary bilateral macronodular adrenal hyperplasia and adrenal cortisol-producing adenoma
Bing LI ; Ming-Xiu YANG ; Huai-Jin XU ; Jing-Xuan WANG ; Qing-Zheng WU ; Ya-Jing WANG ; Yi-Jun LI ; Kang CHEN ; Yu CHENG ; Qi NI ; Ya-Qi YIN ; Li ZANG ; Qing-Hua GUO ; Jian-Ming BA ; Wei-Jun GU ; Jing-Tao DOU ; Zhao-Hui LYU ; Yi-Ming MU
Medical Journal of Chinese People's Liberation Army 2025;50(7):779-785
Objective To comparatively analyze the clinical characteristics of primary bilateral macronodular adrenal hyperplasia(PBMAH)and adrenal cortisol-producing Adenoma(CPA),and enhance the understanding of two diseases.Methods The clinical data of 85 PBMAH patients(PBMAH group)and 195 CPA patients(CPA group)diagnosed at Department of Endocrinology,the First Medical Center of Chinese PLA General Hospital,from September 2014 to August 2024 were retrospectively analyzed.The demographic characteristics,comorbidities,biochemical indicators,adrenocorticotropic hormone-cortisol(ACTH-F)levels,and adrenal imaging features and treatment conditions were compared between the two groups.Results(1)General characteristics:Compared with CPA group,PBMAH group had older age at diagnosis and a higher proportion of male patients.(2)Clinical characteristics:Compared with CPA group,PBMAH group had a longer disease duration,a higher proportion of subclinical Cushing's syndrome(CS),and a higher proportion of hypertension,impaired glucose tolerance/diabetes,bone mass reduction or osteoporosis,with higher serum potassium levels,and the differences were statistically significant(P<0.01).(3)Hormone levels:Both PBMAH and CPA groups showed ACTH-F rhythm disorder,significantly increased cortisol levels and suppressed ACTH.Compared with PBMAH group,CPA group had stronger autonomous cortisol secretion ability,manifested by increased midnight serum cortisol(F0:00),16:00 serum cortisol(F16:00),24-hour urinary free cortisol(24 h UFC)levels and lower 8:00 serum ACTH(ACTH8:00)and 16:00 serum ACTH(ACTH16:00)(P<0.01).After low-dose dexamethasone suppression test(LDDST),CPA group showed lower suppression rates of ACTH and cortisol,and higher proportions of paradoxical elevation in serum cortisol and 24 h UFC compared with PBMAH(P<0.01).Conclusions PBMAH has a longer disease course and higher proportions of comorbid metabolic disorders than CPA,mostly manifested as subclinical Cushing's syndrome.CPA has stronger autonomous cortisol secretion ability,with cortisol less likely to be suppressed after LDDST and more obvious paradoxical elevation of cortisol and 24 h UFC.
6.Clinical and pathological characteristics of adrenal cortical carcinoma:a single-center retrospective study
Qing-Zheng WU ; Ming-Xiu YANG ; Bing LI ; Shu-Ying LI ; Zi-Xin GUO ; Yi-Jun LI ; Ya-Qi YIN ; Ya-Jing WANG ; Kang CHEN ; Li ZANG ; Wei-Jun GU ; Yi-Ming MU ; Zhao-Hui LYU
Medical Journal of Chinese People's Liberation Army 2025;50(7):786-792
Objective To investigate the clinical and pathological characteristics of adrenal cortical carcinoma(ACC),compare differences between hypercortisolism and non-functional ACC,and assess the diagnostic value of indicators such as Ki-67 index.Methods The clinical data of 57 ACC patients admitted to the First Medical Center of Chinese PLA General Hospital from January 2015 to March 2025 were retrospectively analyzed.According to the results of endocrine function assessment,47 of these patients were divided into hypercortisolism group(n=19)and non-functional group(n=28).The differences in clinical and pathological characteristics between the two groups were compared,and non-parametric tests and Spearman correlation analysis were used to explore the relationship between Ki-67 index and tumor stage as well as imaging features.Results Among the 57 patients,there were 20 males and 37 females,with a male-to-female ratio of 1:1.85.The age ranged from 16 to 76 years,and the age at diagnosis was(48.7±13.3)years.The tumor diameter was(10.53±4.14)cm.The tumors were located on the right side in 12 cases(21.1%),on the left side in 34 cases(59.6%),and bilaterally in 11 cases(19.3%).Among them,16 cases(28.1%)were complicated with glucose metabolism disorders,31 cases(54.3%)had hypertension,and 20 cases(35.1%)had hypokalemia.According to ENSAT staging,there were 0 cases in stage Ⅰ,15 cases(26.3%)in stage Ⅱ,24 cases(42.1%)in stage Ⅲ,and 18 cases(31.6%)in stage Ⅳ.Endocrine function assessment was completed in 47 of the 57 patients,including 28 cases(59.6%)of non-functional ACC and 19 cases(40.4%)of hypercortisolism(including 1 case of hypercortisolism combined with increased sex hormone secretion).Compared with non-functional group,hypercortisolism group had a significantly higher prevalence of hypertension(P=0.014),later ENSAT stage(P=0.010),and a higher proportion of hypervascularization(P=0.048).The median Ki-67 index was 20%(10%-40%),showing no significant correlation with either the maximum tumor diameter or SUVmax value,but it was related to ENSAT staging,with Ki-67 index in stageⅣ patients being significantly higher than that in stage Ⅱ(P=0.032).Immunohistochemistry results showed that the positive rate of Inhibin-α was 84.8%,and the positive rate of Melan-A was 40.9%.Conclusions ACC is a rare malignant endocrine tumor.ACC patients with hypercortisolism are more likely to be complicated with hypertension,have later staging,and more common hypervascular manifestations.Clinically,their endocrine function should be prioritized for assessment,and more active treatment strategies should be adopted.Diagnosis should be combined with imaging characteristics(such as hypervascularization)and immunohistochemical indicators(Ki-67,Inhibin-α,Melan-A).The significant increase in Ki-67 is in the advanced stage can serve as an important prognostic indicator to guide individualized treatment.
7.Construction and evaluation of a nomogram model for predicting the risk of hypertension in Dongxiang adults based on obesity and muscle mass indices
Xiu-Lin YANG ; Peng CHENG ; Bin MA ; Wei-Hong MA ; Xiang-Jun HAI
Acta Anatomica Sinica 2025;56(3):336-341
Objective To analyze the relationship between obesity indicators,muscle mass indices and hypertension in Dongxiang adults,and establish and evaluate a Nomogram model based on these indicators used to predict the risk of hypertension in this population.Methods A total of 1209 Dongxiang adults from Linxia Prefecture,Gansu Province were selected,11 obesity indicators and 5 muscle mass indicators,including neck circumference(NC),waist-to-hip ratio(WHR),BMI,ponderal index(PI),conicity index(CI),a body shape index(ABSI),body roundness index(BRI),abdominal volume index(AVI),hip index(HI),body adiposity index(BAI),and the ratio of limb fat mass to body weight(LFWR),appendicular skeletal muscle mass(ASM),appendicular skeletal muscle mass index(ASMI),appendicular skeletal muscle mass to BMI ratio(ASMBMI),skeletal muscle index(SMI),and trunk muscle mass to body weight ratio(TMWR)were measured.Logistic regression analysis was used to explore the relationship between each indicator and hypertension.Nomogram prediction model was constructed and validated by using R language.Results Among Dongxiang males,the NC,BMI,PI,WHR,CI,AVI,BRI,BAI,ASM,ASMI,and LFWR were lower in the normal and high-normal blood pressure groups compared to the hypertensive group,while SMI,ASMBMI,and TMWR were higher.Among females,similar trends were observed,with lower NC,BMI,PI,WHR,CI,AVI,BRI,BAI,and LFWR in the normal blood pressure and high-normal blood pressure groups compared to the hypertensive group,but SMI,ASMBMI,and TMWR higher than the hypertensive group(P<0.05).Results of multivariate Logistic regression analysis indicated that age,NC,and WHR were risk factors for hypertension in Dongxiang adults,while was protective factor(P<0.05).The area under curve(AUC)of the Nomogram model constructed based on these factors was 0.796,and the Bootstrap internal validation C-index was 0.7957,indicating good calibration of the model.Conclusion The Nomogram model constructed based on obesity and muscle mass indicators has good predictive efficiency for predicting the risk of hypertension in Dongxiang adults.
8.Effect of HSYA on LCN2-induced iron death of HT22 cells and its mechanism based on SLC7A11/GPX4 signaling pathway
Meng-wei RONG ; Cun-yan DAN ; Tian-qing XIA ; Yi YANG ; Xiu LOU ; Chen-xiang JI ; Bao-guo XIAO ; Cun-gen MA ; Li-juan SONG
Chinese Pharmacological Bulletin 2025;41(11):2097-2105
Aim To explore the effect of hydroxysafflor yellow A(HSYA)on lipocalin 2(LCN2)-induced fer-roptosis in HT22 cells and the related mechanism.Methods Thirty male Sprague-Dawley(SD)rats were used to establish the middle cerebral artery occlu-sion/reperfusion(MCAO/R)model by the suture method.The rats were randomly divided into the Sham group,the MCAO/R group,and the MCAO/R+HSYA group.The infarct area was measured by TTC staining,and the degree of neurological deficit was evaluated by the Z-Longa scoring method.The expressions of LCN2 and 24P3R in brain tissues were detected by Western blot.LCN2 protein was added to HT-22 cells,and the cells were divided into the normal group,the LCN2 group,and the LCN2+HSYA group.The optimal con-centration of LCN2-induced neuronal ferroptosis was screened by LDH assay and Western blot,and the ex-pression levels of ferritin,FPN1,GPX4,SLC7A11,COX2,and 24P3R were detected.LCN2 was knocked down by siRNA transfection,and the expressions of GPX4 and ferritin were detected.The contents of glu-tathione(GSH),malondialdehyde(MDA),GPX4,and Fe2+were determined by colorimetry,and the expres-sion of GPX4 was detected by immunofluorescence.The binding force between HSYA and LCN2 was ana-lyzed by molecular docking technology.Results Ani-mal experiments showed that HSYA could reduce the cerebral infarction area and decrease the neurological function score of MCAO/R rats.Compared with the sham group,the levels of LCN2 and 24P3R increased in the MCAO/R group,while HSYA inhibited their ex-pressions.Cell experiments showed that the optimal concentration of LCN2 to induce ferroptosis in HT22 cells was 2 μmol·L-1.After knocking down LCN2 by siRNA transfection,compared with the LCN2 group,the expression levels of GPX4 and ferritin in the siLCN2 group increased significantly.Compared with the nor-mal group,the expressions of SLC7A11,GPX4,FPN1,ferritin,and GSH in the LCN2 group decreased signifi-cantly,while the concentration of Fe2+,and the expres-sions of MDA,COX2,and 24P3R increased.HSYA could increase the expressions of SLC7A11,GPX4,FPN1,ferritin,and GSH,reduce the contents of Fe2+and MDA,and inhibit the expressions of COX2 and 24P3R.Molecular docking showed that the binding en-ergy between HSYA and LCN2 was-8.0 kJ·mol-1.Conclusion HSYA can inhibit LCN2-induced ferrop-tosis in HT22 cells through the SLC7A11/GPX4 signa-ling pathway.
9.A Novel Model of Traumatic Optic Neuropathy Under Direct Vision Through the Anterior Orbital Approach in Non-human Primates.
Zhi-Qiang XIAO ; Xiu HAN ; Xin REN ; Zeng-Qiang WANG ; Si-Qi CHEN ; Qiao-Feng ZHU ; Hai-Yang CHENG ; Yin-Tian LI ; Dan LIANG ; Xuan-Wei LIANG ; Ying XU ; Hui YANG
Neuroscience Bulletin 2025;41(5):911-916
10.Complete cfb gene deletion in Streptococcus agalactiae: molecular mechanism of qPCR false negatives
Xiu Wang ; Guiyun Leng ; Yunsi Yang ; Wei Tang ; Qiang Zhou ; Jie Yao
Acta Universitatis Medicinalis Anhui 2025;60(9):1624-1630
Objective :
To investigate the causes of false negative results in the detection of Streptococcus agalactiae using fluorescent quantitative PCR(qPCR) targeting the CAMP factor gene(cfb),and to perform a comprehensive analysis of the associated molecular mechanisms.
Methods:
A total of 76 vaginal secretion samples were evaluated using both qPCR based on cfb gene and bacterial culture methods. Four suspicious strains exhibiting negative qPCR results but positive culture findings were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS),latex agglutination antigen detection,and the CAMP test. Whole genome analysis was conducted utilizing the MGI DNBSEQ-T7 and Nanopore-PromethION 48 sequencing platforms. Phylogenetic and circular evolutionary trees were constructed using the 16S rRNA gene for strain verification. Multilocus sequence typing(MLST) was conducted,and cfb sequences were aligned and analyzed based on spliced sequences and original data. Specific primers targeting the cfb gene were designed for full-length amplification,followed by verification through agarose gel electrophoresis.
Results:
The four strains identified as suspicious were classified as S. agalactiae through MALDI-TOF MS,antigen detection,and 16S rRNA gene analysis,with MLST typing indicating ST-862. Phenotypic analysis revealed a negative CAMP test. Whole genome sequence alignment failed to detect the cfb gene or any homologous sequences,and molecular testing confirmed the absence of cfb gene PCR amplification products,thereby confirming its complete deletion.
Conclusion
This deletion is identified as the molecular mechanism responsible for the false negative qPCR detection of S. agalactiae when targeting this specific gene.It is recommended that the qPCR detection targeting a single cfb gene has limitation,and this may impact clinical diagnosis and treatment decisions. This limitation warrants carefulconsideration.


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