Application of Raman spectroscopy in the rapid detection of pathogenic microorganisms / 中华检验医学杂志

With the rapid development of instrument technology , Raman spectrometer has become one of the fastest growing type of instrument in the molecular spectroscopy . In recent years , Raman spectrometer gradually emerging in the application in the domain of biology and medicine , Raman spectroscopy technology appears new development constantly in the rapid identification and classification of microorganisms because of its rapid , efficient, sensitive, noninvasive, repeatability and other unique advantages.This article describes its application in the rapid detection of bacteria , viruses and other microorganisms , and also prospects for the application of Raman spectroscopy in future clinical work .

Application of terahertz spectroscopy in the detection of cell and tissue / 中华检验医学杂志

As a novel,label-free and non-invasive detection modality,terahertz(THz,1THz=1012 Hz)spectroscopy has been widely used in various areas.For instance,in the biomedical field,it has great potentials to provide real-time scanning of living cells and tissues due to its unique advantages.Significant achievements have been reached in cell detection, related to bacterial identification, cancer cell characterization and blood cell detection.In tissue detection, the THz spectroscopy can be used to provide real-time scanning of living tissues and fast diagnosis.Furthermore, a single system which integrated THz spectroscopy and THz imaging would be able to collect information more sensitive and comprehensive. However,the clinical adaption of THz spectroscopy is still a controversial issue attributed to some intrinsic limitations and technical bottlenecks.In this article, both the application of THz spectroscopy in cell and tissue detection and the existing challenges and strategies to accelerate clinical applications were reviewed comprehensively.

Analysis of distribution of 15249 strains of nosocomial infection pathogens and drug resistance / 国际检验医学杂志

Objective To monitor the distribution of pathogens and the drug resistance of inpatients in Southwest Hospital in ChongQing ,and to analyze the prevalence of pathogens in various departments .Methods A total of 15249 pathogens cultured from clinical specimens in our hospital in 2016 and the antimicrobial susceptibility testing results were retrospectively analyzed .The anti-microbial susceptibility testing was carried out by using the paper diffusion method (K-B) or the automated instrument method (MIC) .The data were analyzed by WHONET5 .5 software according to the standard of CLSI2017-M100 .Results Compared with 2015 ,a total of 15249 pathogenic microorganisms were isolated from the hospital in 2016 ,among which 9742 were Gram-negative bacteria ,down 11 .45% and 4188 were Gram-positive bacteria ,up 15 .34% and 1319 were fungi ,down 11 .48% .Top five depart-ments which collected most microbiological culture specimen were Burn ,Pediatric ,ICU ,Hepatobiliary surgery ,Neurosurgery .The main specimen type of culture was sputum ,accounting for 27 .28% ,followed by blood ,wound secretion ,urine ,abdominal fluid .The first five pathogens were Klebsiella pneumoniae ,Acinetobacter baumannii ,Escherichia coli ,Staphylococcus aureus ,Pseudomonas aeruginosa .Conclusion Gram-negative bacteria are mainly infected organisms in our hospital .However ,Gram-positive bacteria are also important pathogens .Antibiotics should be selected according to the results of antimicrobial susceptibility testing .The distribu-tion of pathogens and the changes of drug sensitivity should be emphasized ,which can provide an effective theoretical basis for treat-ment .

Methicillin-resistant Staphylococcus aureus SCCmec parting and resistance analysis / 国际检验医学杂志

Objective To analyze the clinical distribution ,antimicbial resistance and Staphylococcal cassette chromosome mec (SCCmec) genotype characteristics of 346 methicillirrresistant Staphylococcus aureus (MRSA) clinical isolates in the hospital . Methods A total of 784 strains of Staphylococcus aureus isolated from January 2014 to January 2015 in the hospital ,MRSA identi-fication and the SCCmec genotype was conducted by PCR assay .Results 346 strains of MRSA (44 .13% ) were isolated from 784 strains of Staphylococcus aureus ,the detection rate of MRSA from sputum accounted for 43 .06% ,the secretion accounted for 48 .55% .MRSA was resistant to penicillin ,levofloxacin and erythromycin ,sensitive to vancomycin ,linezolid and teicoplanin .SCC-mec genotyping result showed that SCCmecⅡ was identified in 130 ,SCCmecⅢ in 196 ,SCCmecⅣ in 11 ,SCCmecⅤ in 9 .Conclusion SCCmecⅢ is the main genotypes of MRSA from our Hospital ,all of the MRSA strains are multi-resistant to tested antibiotics , but sensitive to vancomycin and teicoplanin .

Rapid detections of OprD2 gene in Pseudomoas aeruginosa using loop-mediated isothermal amplification / 中华检验医学杂志

Objective To establish a rapid detection approach by visual interpretation directly for OprD2 resistance gene of Pseudomonas aeruginosa based on the Loop-mediated isothermal amplification (LAMP),and provide a quick and effective method for clinical monitoring of Pseudomonas aeruginosa strains.Methods Totally 47 strains of Pseudomonas aeruginosa collected from December 2011 to June 2012 in Southwest Hospital of microorganisms were prospectively studied.Four LAMP primers (two inner,two outer) were designed according to the six zones of the OprD2 gene of Pseudomonas aeruginosa.A positive reaction is indicated by the color change after adding an intercalating dye (hydroxy naphthol blue) to the reaction solution.This method was used to detect and analyze the distribution of OprD2 resistance gene in 47 strains of Pseudomonas aeruginosa and its coirelation with antibiotic resistance.Results The LAMP assays showed 100％ specificity for the OprD2 gene,and the sensitivity (with the lowest detection limits of 17.414 μg/L) was 10-fold higher than that of conventional PCR assays.The OprD2 gene was negative in 23 strains by both conventional PCR and LAMP.In OprD2 negative strains,the resistance rate of cefotaxime,levofloxacin,aztreonam,piperacillin,imipenem and meropenem was 100％ (23/23),57％ (13/23),48％ (11/23),48％ (11/23),48％ (11/23) and 43％ (10/23).Compared with the OprD2 positive strains,statistical analysis showed that the resistance rate of imipenem,levofloxacin and meropenem in OprD2 negative strains increased significantly (chisquare value is 9.155,4.846,4.037,P value was 0.002,0.028,0.045,and so there was significant difference).Conclusions The established LAMP approach in this study enables rapid,sensitive and specific detection of OprD2 gene in Pseudomonas aeruginosa by visual interpretation.Deficiency of OprD2 gene confers Pseudomonas aeruginosa a basal level of resistance to carbapenems especially to imipenem.The identification of OprD2 gene distribution in Pseudomonas aeruginosa is helpful to the selection of antimicrobial agents in the infection treatment.

Genetic Mutations of HBV Core Region / 中华医院感染学杂志

OBJECTIVE To study the mutation profiles of hepatitis B virus(HBV) in the core regions.METHODS Based on the sequence alignment of all HBV genotypes,specific primers targeting all HBV genotypes were designed to amplify the core region of HBV followed by sequence analysis on the sequencing data available.RESULTS Among the 34 cases,23 cases showed mutations in the core region.According to the mutation profiles,the most common mutations were the A1762T(50.0%) and G1764A(52.9%) in the basic core promoter(BCP) regions,and it always showed as double mutations.The L60V in core gene regions was the secondary common mutations(17.6%).Among all patients,there were 18,6 and 10 cases showed mutations in BCP,pre-core,and core gene regions,respectively.The most common mutations in BCP,pre-core,and core gene regions were the double mutations at A1762T and G1764A(94.7%),G1896A(83.3%),and L60V(50.0%),respectively.CONCLUSIONS The most common mutations in the core region of HBV are the double mutations at A1762T and G1764A.Analysis on the mutation profiles of HBV core regions might be helpful for the prognosis and prediction of HBV infections.

Detecting Micro-luminescence of 330 Codon in emb gene of Mycobacterium tuberculosis by Molecular Beacon Hybridization / 中华医院感染学杂志

OBJECTIVE To design molecular beacon detecting embB330 codon of ethambutol-resistant Mycobacterium tuberculosis(MTB),meanwhile,and try to detect fluorescence of mutation site of embB330 codon in liquid by fluorescence microscope by compareing the mutation strains and standard strains.METHODS The software,Beacon designer,was used to design molecular beacon detecting embB330codon and detecting fluorescence signal from hybridization between the amplified product and probe by fluorescence microscope,and to confer to the sequencing results.RESULTS The difference between PCR products from standard strain and ethambutol-resistant one was obvious in detecting the fluorescent light by use of fluorescence microscope.We detected fluorescent light signal between the 33 ethambutol-resistant strains and 10 H37RV standard strains.The rate of ethambutol-resistant strains was about 3%,and the rate of sequencing was about 3%.CONCLUSIONS The technology of molecular beacon effectually can detect mutation single base site of embB330codon.Fluorescence microscope owns characteristics such as high sensitiveness to detect the fluorescent light.

Prevention of Nosocomial Infections in Laboratory Departments of Large Scale Hospitals:Current Situation and Measures / 中华医院感染学杂志

OBJECTIVE To analyze the reasons of nosocomial infection in laboratory departments, and then advance corresponding measures to overcome them. METHODS The current situations in laboratory department between domestic large scale hospitals and overseas hospitals were compared, especially paying attentions to those parts involving in management system and precautionary measures. RESULTS There were a lot of shortcomings existed in the supervision of nosocomial infections in laboratory departments; many measures should be taken to increase the management level. CONCLUSIONS To reform and improve the system of nosocomial infection control and prevention, and establish an effective and systematic alerting and prevention system will benefit all kinds of the hospitals.

DNA Staining Efficiencies of Different Fluorescent Dyes in Preparative Agarose Gel Electrophoresis:A Comparative Analysis / 中华医院感染学杂志

OBJECTIVE To set-up safe alternatives to ethidium bromide(EB).METHODS Comparative analysis was performed on the DNA staining efficiencies of 4 fluorescent dyes including SYBR Gold,SYBR Green Ⅰ,(GoldView) and EB in preparative agarose gel electrophoresis.RESULTS Although both SYBR Gold and SYBR Green Ⅰ altered electrophoretic mobility and thus DNA size estimates,they were cost-effective alternatives to EB.SYBR Gold was more sensitive than SYBR Green Ⅰ at detecting short fragments,but 50 bp bands were clearly(visible) using either dye when visualized with a long integration time.CONCLUSIONS SYBR Gold or SYBR Green Ⅰ are sensitive and relatively safe alternatives to EB.

Detection of Pseudomonas aeruginosa with Piezoelectric Immunosensor Microarray:An Experimental Research / 中华医院感染学杂志

OBJECTIVE To study the main bacteria and their drug-resistance of postoperative infections after liver transplantation.METHODS The distribution and drug-resistance profile of 156 strains of bacterial isolates from(various) specimens in 68 liver transplantation inpatients were retrospectively analyzed last year.RESULTS The(incidence) of infections after liver transplantation was 67.6 %.The major bacteria were Klebsilla pneumoniae((17.3%)),Staphylococcus aureus(14.1%),Candida albicans(11.0%),and Pseudomonas aeruginosa((11.0%)).The bacteria had the character of multidrug-resistance and high drug-resistance.The most effective(antibiotics) to Gram-negatives and Gram-positives were still the carbopenems and glycopeptide.CONCLUSIONS(Infection) is a major complication after liver transplantation.Prevention,early diagnosis and treatment of the(infection) are very important.

Nosocomial Infection Management:Situation and Prevention Strategy in Department of Laboratory / 中华医院感染学杂志

OBJECTIVE To develop the strategies for preventing nosocomial infection in the department of(laboratory).METHODS The current situation in nosocomial infection management in department of laboratory was analyzed.RESULTS There were some problems in training knowledge of nosocomial infection,preparing(equipment) and supplies for prevention,implementing prevention measures,and cultivating good work habit.(CONCLUSIONS) It is very important to strengthen nosocomial infection management for preventing efficiently(nosocomial) infection in the department of laboratory.

Relationship between plasma content of Cu,Zn,Mn,Se and enzymatic activities of SOD and GSH-Px following severe burn injury / 第三军医大学学报

Objective To study the relationship of concentraions of trace elements and the SOD, GSH-Ps activities in plasma following severe burn injury, and provide witness for clinical treatment of trace elements disorder in burned patients. Methods The plasma and urine from 67 severely burned patients in our hospital were collected on day 2, 4, 6, 8, 10, 15, 20, 30 after hospitalization. Trace element levels were determined by atomic absorption spectrophotometry. The vital force of SOD and GSH-Px were measured in plasma with the kits provided by Nanjing Jiancheng bioengineering research institute. Results The ion concentration of Cu in serum got higher and that of Zn got lower after burn, but that of Mn, Se was of no significance. The concentration of Cu, Zn, Mn, Se in urine were increased. The enzymatic activities of T-SOD and Cu, Zn-SOD as well as GSH-Px decreased from the early period to the metaphase. Conclusion For a great deal of oxygen free radicals released by tissues, SOD and GSH-Px were consumed and their concentration decreased in early stage after burn. Due to the trace elements released into blood by destroyed tissues and their increased excretion from urine, tissues could not generate adequate antioxidase, resulting in weak ability against inflammation and poor tissue repair. Our result provides a theoretical clue for the replenishment of trace elements for severely burned patients in early and middle stage and offer a clue to pathology and etiological treatment of burn.

Detection of Staphylococcus aureus by a lambda exonuclease based piezoelectric quartz crystal microbalance DNA sensor / 第三军医大学学报

Objective To develop a new type of piezoelectric quartz crystal microbalance DNA sensor based on lambda exonuclease to detect Staphylococcus aureus (S. aureus) and optimize the main detection conditions. Methods After the DNA was extracted from the stain of S. aureus and the target fragment was amplified with self-designed universal primers, the PCR products were treated with Lambda exonuclease and visualized by agarose gel electrophoresis with ethidium bromide followed by a gel documentation system analysis. Then the products with or without exonuclease digestion were added into our piezoelectric quartz crystal microbalance DNA sensor for hybridization. The temperature and time of hybridization were optimized respectively. The specificity and sensitivity of our detection system were evaluated. Results The optimal temperature for hybridization was 35℃ and the optimal time was 60 min. The sensitivity of the lambda exonuclease based DNA sensor was better than that of common DNA sensor. The lowest detection limit of this new type quartz crystal microbalance system was 1.0?104 CFU/ml. Conclusion The lambda exonuclease based quartz crystal microbalance system we designed has the advantages of high efficiency in hybridization, easy to operate, and good response performance. Thus it can be applied to detect S. aureus infections.

Multichannel piezoelectric genesensor for the detection of human papilloma virus / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To establish a method for rapid detection and sub-typing of human papilloma virus (HPV).</p><p><b>METHODS</b>We utilized the piezoelectric genosensor (PG) technique, which is a combination of the piezoelectric biosensor and gene chips for HPV identification in 22 recurrent biopsy specimens and 22 corresponding original biopsy specimens. The control samples came from normal tissue of healthy persons. A combined reaction took place on the sensor surface between the target genes and probes. The frequency of the piezoelectric sensor will decrease when such reactions occur, and the frequency decrease depends on the concentration of the target gene. Specimens were also analyzed with conventional PCR and dot blot.</p><p><b>RESULTS</b>Of the 22 recurrent specimens, 15 contained HPV6 DNA, 2 HPV11 DNA, and 4 HPV16 DNA. Only one specimen was negative. All the 22 original specimens were positive: 17 harbored HPV6 DNA, 3 sequence homologous HPV11 DNA, and 2 HPV16 DNA. No HPV18 DNA was detected in any specimen. When compared with PCR and dot blot analysis, the results were essentially the same except for one specimen, which was shown to contain other sub-types of HPV.</p><p><b>CONCLUSION</b>Our results show that the piezoelectric genosensor technique is a rapid and specific method to analyze HPV.</p>

The changes of serum and urine guanidinoacetic acid level after cadmium chloride-induced renal injury in rabbits / 第三军医大学学报

Subcutaneous injection of 1.0 mg/kg cadmium chloride in 0.8% solution was given to rabbits weighing 1.7~2.5kg 3 times a week for 10 weeks.An equal volume of normal saline was injected to the rabbits of the control group.Blood specimen from the auricle vein and 24-hour-urine of every rabbit were collected once a week.Ten weeks later the renal cortex of the rabbits WES resected,processed routinely and examined under optical microscopy,The level of guanidinoacetic acid (GAA) of the serum and urine was determined with HPLC.It was found that the serum level of GAA increased after 3 weeks of cadmium administration while urinary excretion of GAA increased slightly in the first week and decreased significantly in the second week of cadmium injection and thereafter.