1.Distribution and drug resistance of pathogens isolated from urinary tract infections
Huazhi LING ; Jilu SHEN ; Zhongxin WANG ; Yuanhong XU
Chinese Journal of Clinical Infectious Diseases 2014;7(2):105-110
Objective To investigate the distribution and drug resistance of pathogens isolated from urinary tract infections.Methods A total of 6 262 midstream urine samples were collected from patients in the First Alfiliated Hospital of Anhui Medical University during April 2012 and March 2013.MicroScan WalkAway 96 Plus or Vitek 2 Compact system was applied in bacteria identification and drug sensitivity test.WHONET 5.6 was adopted to analyze drug resistance,and IBM SPSS 20.0 was applied to compare resistance rates between isolates from outpatients and hospitalized patients.Results A total of 1 426 strains were isolated,in which 370 strains were gram-positive coccus (25.9%),942 strains were gram-negative bacilli (66.1%) and 114 strains were fungi (8.0%).Escherichia coli and Klebsiella pneumoniae,Enterococcus faecium and Enterococcus faecalis were the top two among gram-negative bacilli and grampositive coccus,respectively.The prevalence of extended-spectrum β-lactamases (ESBLs)-producing Escherichia coli,Klebsiella pneumoniae and Proteus mirabilis were 60.5%,51.0% and 30.3%,respectively; About 73.3% of Staphylococcus aureus strains and 86.7% of coagulase-negative Staphylococcus strains were methicillin-resistant.Candida albicans and Candida glabrata were the two most prevalent fungi in urinary tract infections,and they were sensitive to most antifungal agents.Conclusion Gram-negative bacilli,especially Escherichia coli are the most prevalent pathogen in urinary tract infections,and strains are highly resistant to most antibacterial agents,suggesting that antimicrobial resistance monitoring system is needed.
2.Distribution and antibiotic resistance of the pathogens isolated f rom bloodstream infections
Huazhi LING ; Jilu SHEN ; Zhongxin WANG ; Yuanhong XU
Chinese Journal of Infection and Chemotherapy 2014;(5):420-424
Objective To investigate the distribution and antibiotic resistance of the pathogens isolated from blood culture . Methods Identification and antimicrobial susceptibility testing were performed with MicroScan WalkAway 96 PLUS or VITEK 2 compact .WHONET 5 .6 software was used for analysis of the susceptibility data according to CLSI 2013 breakpoints .IBM SPSS 20 .0 was employed to compare the resistance rates between groups . Results Gram-positive bacteria , gram-negative bacteria and fungi accounted for 57 .8% ,36 .0% and 6 .2% of the 503 nonduplicate isolates ,respectively .The most common isolates included coagulase-negative Staphylococcus , Escherichia coli , Enterococcus spp ., Staphylococcus aureus and K lebsiella pneumoniae . The prevalence of methicillin-resistant S . aureus (MRSA ) and coagulase-negative Staphylococcus (MRSCN) was 32 .3% and 71 .7% respectively .The coagulase-negative Staphylococcus isolates from ICU patients showed higher resistance rates to many antibiotics than those non-ICU strains (P<0 .05) .E .coli and K .pneumoniae strains showed high percentage of resistance to cephalosporins , but relatively low resistance to piperacillin-tazobactam , imipenem and amikacin .A .baumannii isolates were highly resistant to most antimicrobial agents . Candida species were less resistant to antifungal agents .Conclusions The pathogens isolated from blood culture are diverse .The resistance profile is quite different among various pathogens .The distribution and antibiotic resistance should be actively monitored for the pathogens isolated from blood culture in order to facilitate the rational use of antimicrobial agents .
3.Detection of Extended-spectrum Beta-lactamases and Genotypes in Escherichia coli and Klebsiella isolates in Wannan Area
Chun PU ; Xiaoning LI ; Huazhi LING ; Yuanhong XU
Chinese Journal of Nosocomiology 2006;0(09):-
OBJECTIVE To investigate the ESBLs-producing isolates and their resistance and genotypes in Escherichia coli and Klebsiella in three hospitals of Wannan area.METHODS The MIC of 13 antimicrobials against 79 strains of E.coli and Klebsiella were determined by 2-fold agar dilution method.The confirmation test was used to detect ESBLs-producing strains according to CLSI 2005.PCR method was used to amplify beta-lactamases of ESBLs-producing isolates by 8 premiers,PCR products were purified and then sequencing was performed.RESULTS The ESBLs-producing rates in E.coli and Klebsiella in three hospitals of Wannan area were 61.5% and 45.0%,respectively.The resistance rates to CRO,CTX,CAZ,CIP and LEV of ESBLs-producing strains were 81.0%,81.0%,47.6%,71.4% and 50.0%,respectively,all isolates were susceptible to meropenem and imipenem.PCR indicated that CTX-M1,CTX-M13,TEM and OXA1 types of beta-lactamases were the four major genotypes of the three hospitals in Wannan area.CONCLUSIONS The isolation rates of ESBLs-producing E.coli and Klebsiella as well as their resistance rates to cephalosporins and quinolones in the three hospitals in Wannan area are quite high.Monitoring ESBLs-producing isolates should be strengthened in clinic and laboratory.
4.Analysis of clinical characteristics and risk factors for 92 cases of nosocomially acquired candidemia
Zhongxin WANG ; Naifang YE ; Boyun ZHANG ; Ying HUANG ; Huazhi LING ; Jilu SHEN ; Yuanhong XU
Chinese Journal of Infectious Diseases 2016;34(4):232-236
Objective To investigate the clinical features and prognostic factors of nosocomially acquired candidemia.Methods A retrospective analysis was conducted for hospitalized patients with nosocomial candidemia between January 2012 and December 2014 at the First Affiliated Hospital of Anhui Medical University.The univariate and multivariate Logistic regression analyses were used to determine the prognostic factors of candidemia.Results A total of 92 patients were diagnosed with nosocomially acquired candidemia.The most common pathogen was Candida glabrata (C.glabrata,39/92,42.4%),followed by Candida albicans (C.albicans,30/92,32.6%),then Candida krusei (C.krusei,7/92,7.6%),Candida tropicalis (C.tropicalis,5/92,5.4%),Candida parapsilosis (C.parapsilosis,4/92,4.4%) and other Candida spp.(7/92,7.6%).The sensitivity rates of Candida spp.strains against flucytosine,amphotericin B,voriconazole,fluconazole and itraconazol were 100.0%,98.9%,92.4%,82.6%oo and 77.2%,respectively.The 30-day attributable case fatality rate was 13.0%(12/92).Multivariate Logistic regression analyses indicated that presence of central venous catheter (OR=4.833,95%CI:1.010-23.125,P=0.049),invasive mechanical ventilation (OR=6.075,95%CI:1.144-32.257,P=0.034),and receiving hemodialysis (OR =8.367,95 % CI:1.390-50.364,P =0.020)were factors independently correlated with increased mortality.Conclusions The pathogens causing nosocomially acquired candidemia are mainly C.glabrata,C.albicans and C.krusei.The drug susceptibility of Candida spp.varies among fluconazole,itraconazol voriconazole.The resistant rates of Candida spp.against voriconazole,fluconazole and itraconazol are different.The presence of central venous catheter,invasive mechanical ventilation and receiving hemodialysis are factors independently correlated with increased mortality.
5.Detection of Beta-lactamases in Multi-resistant Citrobacter Strains
Mei ZHU ; Wei XU ; Tao LI ; Huazhi LING ; Ying HUANG ; Yuanhong XU
Chinese Journal of Nosocomiology 2006;0(09):-
OBJECTIVE To investigate beta-lactamases production in multi-resistant Citrobacter strains isolated from the First Affiliated Hospital of Anhui Medical University.METHODS Standard agar dilution method was used to determine the minimal inhibitory concentration(MIC) of 52 clinically isolated Citrobacter strains,improved three-dimensional tests were performed to detect the ESBLs-producing,AmpC-producing and MBL-producing strains in 31 Citrobacter isolates,then beta-lactamases-encoding genes were amplified by polymerase chain reaction(PCR).RESULTS Thirty one Citrobacter strains were resistant to many beta-lactams antibiotics.Twenty four strains ESBLs-producing,3 AmpC-producing and 2 ESBLs-producing plus AmpC-producing strains have been detected by improved three-dimensional tests,and not found MBL-producing ones.Twenty strains had blaTEM gene and 1 strain had blaSHV gene,8 strains had blaCTX-M-1 gene,15 strains had blaCTX-M-13 gene and 5 strains had blaCIT gene by PCR.CONCLUSIONS Multi-resistant Citrobacter strains produce one or more types of ESBLs and AmpC beta-lactamase,it may be an important reason of resistance to beta-lactams antibiotics.
6.Detection of Metallo-?-lactamase Produced by Chryseobacterium indologenes and Their Genotypes
Xianghong LIN ; Tao LI ; Mei ZHU ; Huazhi LING ; Xiaoli CHEN ; Yuanhong XU
Chinese Journal of Nosocomiology 1994;0(01):-
OBJECTIVE To investigate the antibiotical resistance and to understand the phenotype and genotype of metallo-?-lactamase in Chryseobacterium indologenes.METHODS The MIC to 25 C.!indologenes strains was detected by agar dilution method.Phenotype of metallo-?-lactamase was detected by three-disc synergy test and modified three dimension test.Polymerase chain reaction(PCR)amplification for both metallo?-lactamase and integrase gene was conducted for all isolates.Complete coding gene of metallo-?-lactamase and their DNA sequence analysis was conducted.Conjugation experiment was used to study the transmission of metallo-?-lactamase encoding gene.pIs Of ?-lactamase was measured by isoelectric focusing assay.RESULTS The antibiotical resistance of C.indologenes to imipenem and meropenem was 88.0%,respectively.However,gatifloxacin,levofloxacin and rifampin had better antimicrobiotial ability to C.indologenes compared with other antibiotics in MIC Nineteen strains were identified to produce metallo-?-lactamase using three-disc synergy test and modified three dimension test.Twenty strains were detected to have metallo-?-lactamase genotype by PCR amplification using IND-like common prime sets and four prime sets of complete coding gene.Among them,9 strains were detected to have blaIND-1 genotype and 10 strains to have blaIND-2 genotype,strain CI-25 was identified to have blaIND-like genotype.The mutation of base sequences and amino acid sequences in 5 strains were found simultaneously.Conjugation experiment showed that metallo-?-lactamase encoding gene couldn′t transfer.Nineteen strains had 1 or 2 bands on isoelectric focusing electrophoresis.Strain CI-5 was proved to have blaIND-1,but phenotype of metallo-?-lactamase was negative.CONCLUSIONS C.indologenes has high rate of metallo-?-lactamase producing,and thus it is difficult to treat.The major genotype of metallo-?-lactamase for C.indologenes is blaIND-1 and blaIND-2 in Hefei.The expression of blaIND could exist negative or low level occasionally.
7.Protective effects of hedysarum polybotrys polysacchcaide on renal inter-stitid fibrosis in db /db mice with early diabetic nephropathy
Zhisheng JIN ; Yujiao WEI ; Hailong LING ; Huazhi ZHANG
Journal of Beijing University of Traditional Chinese Medicine 2017;40(8):677-683
Objective To investigate the influence of hedysarum polybotrys polysacchcaide (HPS)on the expression of transforming growth factor-β1 (TGF-β1 )and connective tissue growth factor (CTGF)as well as its kidney-protective mechanism in early diabetic nephropathy (DN)db /db mice.Methods 60 male mice at SPF 6 were used for this study.The above 50 db /db mice were divided into 5 groups (n =10 in each group)by using the random number table method:high-dose,mid-dose and low-dose HPS group (200,100,50 mg/kg,ig),telmisartan group (5 mg/kg,ig),and model group (distilled water of the same volume,ig).The remaining 10 db /m mice in the normal control group received equal vol-ume of distilled water via intragastric administration for 8 weeks.For mice in all groups,blood glucose levels were measured before the experiment and once every two weeks after intervention.24h urine was collected at the end of week 4 and 8 to measure urinary albumin levels by using ELISA method.Blood samples were drawn from the eyeball veins to measure the levels of serum creatinine (Scr)and blood urea nitrogen (BUN).Rat kidney tissue was dissected after sacrifice of these mice.Left kidney underwent HE staining to observe pathological changes in the renal cortex while the right kidney was used to detect the expression of TGF-β1 and CTGF mRNA and protein by using RT-PCR and Western blotting.Results Compared with the normal control group,blood glucose,Scr,BUN and 24 h urinary albumin levels in-creased significantly (P <0.01)in the model group;glomerular hypertrophy,mesangial widening,and capillary basement membrane thickening were observed.Expressions of TGF-β1 and CTGF mRNA and protein were significantly increased (P <0.01).Compared with the model group,blood glucose,Scr, BUN and 24 h urinary albumin levels decreased significantly (P <0.05)in all treatment groups except the low-dose HPS group (P >0.05);glomerular hypertrophy,mesangial widening and capillary base-ment membrane thickening presented with different degrees of improvement;expressions of TGF-β1 and CTGF mRNA and protein significantly decreased (P <0.01);curative effect of the mid-dose HPS group was superior to that of the telmisartan group.Conclusion HPS could prevent early diabetic nephropathy (DN)in db /db mice;its mechanism may be related to the inhibition of TGF-β1 and CTGF mRNA ex-pression level in the kidney.
8.Visualization analysis of global research hotspots on exosomes in ophthalmology using CiteSpace and VOSviewer
Ying GAO ; Xiangxia LUO ; Huazhi ZHANG ; Lei ZHANG ; Juan LING ; Jiayuan ZHUANG
International Eye Science 2025;25(4):565-572
AIM: To investigate the global research status, hotspots, and trends of exosome studies in ophthalmology, providing a theoretical foundation and constructive references for future research, and promoting in-depth development in this field.METHODS: Relevant literature on exosomes in ophthalmology published up to May 20, 2024, was retrieved from the China National Knowledge Infrastructure(CNKI), Web of Science Core Collection, and PubMed databases. Visual analyses of publication countries, institutions, authors, high-frequency keywords, burst keywords, and timelines were performed using CiteSpace 6.3.R1 and VOSviewer software.RESULTS: A total of 37 Chinese articles and 548 English articles were included. The top five countries in terms of publication volume were the United States(130 articles), China(80 articles), South Korea(24 articles), the United Kingdom(20 articles), and Japan(19 articles). The leading foreign institutions were the University of California System, Duke University, and Harvard University, while the top domestic institutions were Qingdao University, the Department of Ophthalmology at the First Affiliated Hospital of Jinan University, and the School of Physical Education and Sports Science at Beijing Normal University. Analysis of Chinese and English high-frequency and burst keywords indicated that global research hotspots on exosomes in ophthalmology primarily focus on dry eye, extracellular vesicles, mesenchymal stem cells and their derived exosomes, ocular surface diseases, ocular surface inflammation, biomarkers, retinal protection, immune eye diseases, uveitis, degenerative eye diseases, macular degeneration, diabetic retinopathy, neovascularization, thyroid-associated ophthalmopathy, and glaucoma, while English high-frequency words mainly were dry eye, dry eye disease, delivery, regenerative medicine, uveal melanoma, protein, and transplantation. Research has evolved from initial basic biological studies to exploring the pathogenesis of ocular diseases and advancing toward novel diagnostic and therapeutic approaches.CONCLUSION: Over the past 5 a, research on exosomes in ophthalmology has grown rapidly. Exosomes, as novel biomarkers and potential therapeutic targets, have become central to studies on the pathogenesis and clinical applications of ophthalmic diseases. Their roles in the diagnosis, treatment, and prevention of these diseases represent promising directions for future research.