1.Analysis of pathogen distribution and antibiotic resistance in infections after solid organ transplantation from 2017 to 2022
Peiling GUO ; Lijuan WU ; Yuanfang WANG ; Yuling XIAO ; Yi XIE
International Journal of Laboratory Medicine 2025;46(10):1227-1233
Objective To analyze the characteristics and drug resistance of pathogenic bacteria isolated from patients undergoing solid organ transplantation(SOT)at West China Hospital,Sichuan University in re-cent years,in order to provide a basis for empirical anti infective treatment after SOT surgery.Methods A retrospective analysis was conducted on the isolation of major pathogens and their resistance to common anti-biotics from various specimens collected from patients undergoing kidney transplantation(KT),liver trans-plantation(LTx),and lung transplantation(LT)at West China Hospital,Sichuan University from 2017 to 2022.Results A total of 1 077 non-duplicate strains of pathogens were isolated from the samples of patients with infections after SOT surgery during the 6-year period,of which approximately 74.8%(806/1 077)were Gram negative bacteria and 25.2%(271/1 077)were Gram positive bacteria.There were differences in the distribution of pathogenic bacteria among different types of SOT groups and different specimens.Compared to E.coli isolated from urine specimens,the strains of E.coli isolated from non-urinary specimens exhibited a higher resistance rate to common antimicrobial drugs(P<0.05).The resistance rate of E.coli to β-lactam/β-lactamase inhibitor combinations(cefoperazone/sulbactam and piperacillin/tazobactam)in the LTx group was significantly higher than that in the KT group(P<0.05).The overall proportion of multidrug-resistant bac-teria after SOT surgery was 11.3%(122/1 077).The proportion of carbapenem resistant Acinetobacter bau-mannii and carbapenem resistant Pseudomonas aeruginosa among the same group and type of pathogens in the LTx group(93.8%,37.5%)was significantly higher than that in the KT group(55.8%,9.2%).Conclusion The specimen types and strain distribution of pathogenic bacteria after different types of SOT surgery are different.The same pathogenic bacteria have different antibiotic resistance among different types of SOT groups and specimens.Therefore,it is necessary to strengthen the pathogen examination after different types of SOT and optimize the anti infection treatment plan related to transplantation based on drug sensitivity re-sults.
2.Diagnostic value of Treponema pallidum antibody index detected by electrochemiluminescence immunoassay in neurosyphilis
Sirui WU ; Yuanfang WANG ; Lan LUO ; Jielun DENG ; Dongdong LI ; Yi XIE
Chinese Journal of Microbiology and Immunology 2024;44(6):545-552
Objective:To evaluate the value of Treponema pallidum ( Tp)-specific antibody index in the diagnosis, staging, and typing of neurosyphilis (NS). Methods:Fifty patients diagnosed with NS at the West China Hospital of Sichuan University from March 2020 to December 2022 were recruited as the experimental group, and 50 non-NS syphilis patients were enrolled during the same period as the control group. Cerebrospinal fluid (CSF) and matched serum samples along with clinical data were collected. Clinical and Laboratory Standards Institute (CLSI) EP06-Ed2 file was used to analyze the linear range of electrochemiluminescence immunoassay for Tp-specific antibody detection, and the Tp antibody index was calculate for all subjects. The correlation of Tp antibody index, IgG index, IgG synthesis rate, and albumin quotient with other clinical indicators was evaluated by the coefficient of correlation, and the diagnostic efficacy of these indicators in NS was analyzed using the receiver operating characteristic (ROC) curve. Results:All the deviations from linearity of electrochemiluminescence immunoassay for detecting Tp antibodies in serum and CSF samples were within the allowable deviation from linearity. Compared with the non-NS group, the NS group showed a significant increase in the Tp antibody index ( P<0.05), with no significant differences observed among the groups of different subtypes, severity, or receiving treatment or not ( P>0.05). Tp antibody index, IgG index, and IgG synthesis rate were positively correlated with serum Tp antibody, CSF Tp antibody, trace protein, and nucleated cell count ( P<0.05). Taking 14.99 as the cut-off value for NS diagnosis, the diagnostic sensitivity of Tp antibody index was 74.0% (95%CI: 60.5%-84.1%), and the specificity was 94.0% (95%CI: 83.8%-98.4%), with the area under the ROC curve of 0.897, which was larger than that of albumin quotient, IgG index, and IgG synthesis rate. Conclusions:This study finds a significant increase in the Tp antibody index in NS patients with good diagnostic sensitivity and specificity, providing reference for the diagnosis of NS.
3.Distribution and Antibiotic Resistance Analysis of Ocular Bacterial Pathogens at a Tertiary Hospital From 2012 to 2021
Dan ZHOU ; Yuanfang WANG ; Jin DENG ; Yuling XIAO ; Yi XIE
Journal of Sichuan University (Medical Sciences) 2024;55(1):204-209
Objective To analyze the distribution of ocular bacterial pathogens and their antibiotic resistance status at a tertiary-care hospital and to provide a reference for the appropriate use of antibiotics.Methods Retrospective analysis was conducted with bacteria isolated from the ophthalmic samples sent for lab analysis at a tertiary-care hospital from 2012 to 2021.The suspected bacterial strains were identified with automated systems for microbial identification and susceptibility analysis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometer.VITEK 2 Compact,an automated microbial identification and antibiotic susceptibility analysis system,was used for antimicrobial susceptibility testing.Results A total of 1556 ophthalmology bacteria culture samples were collected,574 of which showed bacterial growth,presenting an overall positive rate of 36.89%.Of the isolated bacteria,Gram-positive cocci,Gram-positive bacilli,Gram-negative bacilli,and Gram-negative cocci accounted for 63.15%(377/597),18.76%(112/597),17.09%(102/597),and 1.00%(6/597),respectively.Among the bacteria isolated in different years over the course of a decade,Gram-positive cocci always turned out to be the main cause of eye infections.Of the Gram-positive cocci,73.47%(277/377)were isolated from patients with endophthalmitis,with the most important species being Staphylococcus epidermidis,which was followed by Streptococcus viridans.The rest,or 26.53%(100/377),of the Gram-positive cocci were isolated from patients with external eye infections,with the main isolated strains being Staphylococcus epidermidis,Streptococcus viridans,and Staphylococcus aureus.More than 70%of Staphylococcus epidermidis isolated from both endophthalmitis and external eye infections were resistant to methicillin.No strains resistant to vancomycin,linezolid,or tigecycline were detected.Staphylococcus epidermidis isolated from patients with external eye infections had a low rate of resistance to levofloxacin(2/27 or 7.41%),whereas those isolated from patients with endophthalmitis had a higher resistance rate(43/127 or 33.86%).The difference in drug resistance rate between the two groups was statistically significant(P<0.05).Conclusion The chief ocular bacterial pathogens identified in a tertiary-care hospital were Gram-positive cocci,among which,Staphylococcus epidermidis was the most common species.The Staphylococcus epidermidis identified in the hospital had a high rate of resistance to oxacillin,but remained highly sensitive to vancomycin,linezolid,and tigecycline.The endophthalmitis caused by Staphylococcus epidermidis in the hospital can be treated empirically with vancomycin and then the treatment plan can be further adjusted according to the results of the drug susceptibility test.However,the establishment of the breakpoint of drug susceptibility test is mainly based on the model of bloodstream infection and has limited reference value for the treatment of eye infection.The required drug distribution concentration at the infection site can be achieved by dose increase or local administration.
4.Analysis of values and differences of multi-modality registration and normalization methods in 18F-AV45 PET imaging for Alzheimer′s disease
Hongbo FENG ; Yuanfang JIANG ; Jinghui XIE ; Xuemei DU
Chinese Journal of Nuclear Medicine and Molecular Imaging 2023;43(7):385-390
Objective:To explore values and differences of multi-modality image registration and normalization methods in 18F-AV45 PET quantitative analysis of Alzheimer′s disease (AD). Methods:Twenty AD patients (10 males, 10 females; age (77.0±5.8) years) and 20 normal controls (NC; 8 males, 12 females; age (75.2±4.8) years) from the AD neuroimaging initiative (ADNI) open database of the National Institute on Aging were analyzed. β-amyloid (Aβ) deposition (positive/negative) was assessed by visual analysis. The SUV ratio (SUVr) in each brain region and individual average SUVr were calculated using template normalization method (M1), normalization after registration with 18F-FDG PET or MRI image (M2 or M3) respectively with the cerebellum as the reference area. The intra-class correlation coefficient (ICC) was used to complete the reliability between methods, and independent-sample t test and one-way repeated measures analysis of variance were used to compare the differences of quantitative indexes between different groups and different methods. ROC curve analysis was used to compare the diagnostic efficacy in distinguishing AD and NC, Aβ positive and negative cases. Results:There were 15 and 6 patients with positive Aβ deposition in AD group and in NC group respectively by visual analysis. The SUVrs of three methods were with good consistency (ICC=0.82, P<0.001), and the differences among individual average SUVrs (1.29±0.17, 1.36±0.23, 1.45±0.24) were significant ( F=68.78, P<0.001). There were significant differences between AD group (1.39±0.17, 1.48±0.24, 1.58±0.25) and NC group (1.20±0.10, 1.24±0.15, 1.33±0.16; t values: 3.55-4.33, all P<0.05), Aβ positive group (1.39±0.16, 1.50±0.21, 1.59±0.23) and negative group (1.19±0.11, 1.21±0.14, 1.31±0.15; t values: 4.58, 5.11, 4.41, all P<0.001), and the individual average SUVr of M3 was higher (both P<0.001). The AUCs of distinguishing Aβ positive and negative deposition of M1-M3 were 0.86, 0.88, 0.84 and the thresholds of SUVrs were 1.29, 1.37, 1.52, respectively. Conclusion:The three multi-modality registration and normalization methods are reliable methods for quantitation of 18F-AV45 PET imaging with certain differences, and should be selected carefully based on data conditions in practice.
5.Research on the quality of Centella asiatica collected in different months based on fingerprint and multi-components determination
Tao ZOU ; Huilong FANG ; Junjie WANG ; Qing LIU ; Siyu LIU ; Yuanfang ZHANG ; Pengfei XIE ; Jianhua HUANG
International Journal of Traditional Chinese Medicine 2022;44(8):910-916
Objective:To establish the HPLC fingerprint of Centellae herba and determine the content of asiaticoside, madecassic acid and asiaticoside B simultaneously; To compare the quality differences of Centellae herba collected in different months. Methods:The chromatographic condition was a Shimadzu InertSustain C18 column (4.6 mm×250 mm, 5 μm) with a mobile phase consisting of acetonitrile and 2 mmol/L beta cyclodextrin in gradient elution at the flow rate of 0.8 ml/min. The detection wavelength was 204 nm, and the column temperature was 30 ℃. The different Centellae herba materials of collected in 2-12 months from Chenzhou were studied by the similarity evaluation combined with cluster analysis, principal component analysis and the three contents determination. Results:The HPLC fingerprint of Centellae herba was established and 9 common peaks were designated. The eleven samples were different, which can be aggregated into 4 categories and the quality of Centellae herba collected in July was the best. Conclusion:The established fingerprint and multi-components quantitative method are stable and reliable, which can provide a reference for the quality control and the utilization of Centellae herba resource.
6.Advances of 18F-FDG PET/CT in the detection of brown adipose tissue
Jianhao XIE ; Xinyi CHENG ; Yuanfang ZHANG ; Yujie XU ; Chao MA
Chinese Journal of Nuclear Medicine and Molecular Imaging 2020;40(8):501-504
Nowadays, more attentions have been paid on brown adipose tissue (BAT) because BAT plays a great role in individuals with obesity and metabolic diseases. 18F-fluorodeoxyglucose (FDG) PET/CT is noninvasive and sensitive to detect the location, volume, and metabolic activity of BAT. 18F-FDG PET/CT for BAT provides new insight for the prevention and clinical management of obesity and diabetes. The review summarizes the methods to activate BAT, the preparation of patients, 18F-FDG PET/CT imaging techniques and clinical application.
7. Epidemiological characteristics of non-fermentative bacteria causing bloodstream infection in Sichuan: a retrospective multicenter study
Yuanfang WANG ; Keping AO ; Xuedong HUANG ; Jielun DENG ; Yi XIE ; Xianli WU ; Mei HUANG ; Xiangmei JIANG ; Xiaozheng WEN ; Jun YING ; Haijun LI ; Yin XIANG ; Xuemei XU
Chinese Journal of Microbiology and Immunology 2019;39(9):698-704
Objective:
To retrospectively analyze the distribution of non-fermentative bacteria causing bloodstream infection in hospitalized patients in Sichuan Province and their drug susceptibility to common antibiotics for better understanding their epidemiological characteristics.
Methods:
From January 1, 2015 to December 31, 2017, all of the non-fermentative bacteria isolated from patients with bloodstream infection in nine hospitals in Sichuan Province were collected. Species distribution and drug resistance test results were retrospectively analyzed.
Results:
A total of 6 291 strains of pathogenic bacteria were isolated, including 3 674 strains of gram-negative bacteria (58.4%) and 2 617 strains of gram-positive bacteria (41.6%). The gram-positive bacteria were 1 895 strains of
8.Teaching reform of diagnostics based on clinical skill competition
Bo HUANG ; Yuanfang DUAN ; Hong MEI ; Jianping XIE
Chinese Journal of Medical Education Research 2017;16(4):346-350
In view of the current situation of the teaching of diagnostics, this paper analyzes the ex-isting problems and deficiencies , and puts forward the teaching reform of the National Medical College Students' clinical skills competition. Through the construction of experimental teaching demonstration center of clinical skills, we set up theclinical skills associationamong the students, boldly try innovative training, strengthen humanistic education and take other measures to improve the quality of clinical practice teaching of diagnostics, so as to achieve the purpose of the competition focusing on promote teaching, learning and using by competition.
9.Clinical study of PEI combined with HIFU for treating unresectable middle and advanced stages of primary liver cancer
Guangping WU ; Yuanfang PU ; Tian TIAN ; Yong PANG ; Ke CAO ; Yong YANG ; Bo XU ; Yuan LI ; Yan XIE ; Min HE
Chongqing Medicine 2015;(10):1367-1369
Objective To investigate whether the percutaneous ethanol injection (PEI)under sedation and analgesia can in-crease the energy deposition and curative efficiency of the high intensity focused ultrsound(HIFU)in treating unresectable middle and advanced stages of primary liver cancer.Methods Thirty-six cases of clinically diagnosed unresectable middle and advanced sta-ges of primary liver cancer were randomly divided into the PEI+ HIFU group(combination group,n = 23)and the simple HIFU group (HIFU group,n=13);10mL of the mixture of 99.7% ethanol and iodized oil (9:1)was given by intratumoral injection at 30 min before ablation in the PEI+HIFU group,while 0.9% physiological saline 10mL was replaced in the simple HIFU group.The ablation energy efficiency factor(EEF)and irradiation time were compared between the two groups.Results The ablation EEF in the PEI+HIFU group and the simple HIFU group were (13.82+4.26)J/mm3 and (25.63+6.31)J/mm3 respectively,the PEI+HIFU group was significantly lower than the simple HIFU group (P <0.05);the irradiation time were (1 468.28+253.21)s and (2 352.56+463.34)s respectively;which in the PEI+ HIFU group was significantly shortened (P <0.05).Conclusion PEI can enhance the HIFU ablation energy deposition and improve the efficiency of HIFU for treating unresectable primary liver cancer.
10.Eeffect of K65R site-mutagenesis of cataracts-related gene Hsf4b on downstream heat shock proteins expression
Qiang LOU ; Panpan XIE ; Xiukun CUI ; Yuanfang MA ; Yanzhong HU
Chinese Journal of Pathophysiology 2015;(9):1699-1703
AIM:To clarify the impact of heart shock factor 4b (Hsf4b) K65R mutation on the regulation of downstream protein expression .METHODS:Non-functional Lys mutant plasmid pWZL-blast-HA-Hsf4b/K65R was genera-ted by replacing single , homologous amino acids using KOD-Plus-Mutagenesis-Kit.Mouse lens epithelial mLEC stable cell lines expressing Hsf4b or Hsf4b/K65R were constructed by lentivirus infection .The expression of Hsf4b in the mutant and the wildtype mLEC cells was confirmed by Western blotting .The expression of Hsf4b downstream proteins such as heat shock protein ( Hsp)70, Hsp90, Hsp27 and CryAB was examined by Western blotting and real-time PCR.RESULTS:The results of PCR and DNA sequencing confirmed the successful construction of mLEC Hsf 4b/K65R mutant.The K65R mutation didn’t influence Hsf4b expression in the mLEC cells.After K65R mutation in Hsf4b, the expression levels of Hsp27 and CryAB were down-regulated and the expression of Hsp 70i and Hsp90a upregulated.CONCLUSION: pWZL-blast-HA-Hsf4b/K65R can be used to construct a stable cell line by infecting with lentivirus .Hsf4b/K65R mutation influ-ences the regulation of downstream heat shock proteins .

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