[ Objective ] The paper was to isolate and identify Ralstonia solanacearum from white burley, and determine its susceptibility to 6 fungicides. [ Mcth- od] Using the combination method of semiselective medium （PCCG）...[ Objective ] The paper was to isolate and identify Ralstonia solanacearum from white burley, and determine its susceptibility to 6 fungicides. [ Mcth- od] Using the combination method of semiselective medium （PCCG） and apolymerase chain reaction （PCR） technique, R. solanacearum in stalk of white burley from Dazhou City in Sichnan Province was isolated, and its biochemical type was identified. Through susceptibility test, the susceptibility of R. solanacearum to bismerthiazol, ethylicin, streptomycin, lime sulfur, 47% polylysine, 99% kojic acid was studied in laboratory. [Result] A total of 23 strains OfR. solanacearum were isolated, all belonging to biochemical type Ill. R. solanacearum obtained in the test were more susceptible to ethylicin, streptomycin and bismerthiazol, and ethylicin had good control effect against R. solanacearum with ECso of 0.086 ml/L. [ Conclusion ] The study provide theoretical basis for control of R. solanaceanon in white burley.展开更多
Background: In India, tuberculosis (TB) is a major public health problem, and the advent of drug resistance TB (DR-TB) has worsened the situation. The Revised National TB Control Programme (RNTCP) has introduced unive...Background: In India, tuberculosis (TB) is a major public health problem, and the advent of drug resistance TB (DR-TB) has worsened the situation. The Revised National TB Control Programme (RNTCP) has introduced universal drug susceptibility testing (UDST) for all diagnosed TB cases in 2018. We conducted this study to know the advantage of implementing UDST when compared to selective testing existent in 2017 on key diagnostic cascade parameters and to identify the challenges in the implementation of UDST. Methods: The study was conducted in two districts of Karnataka, India during January 2017-December 2018. The quantitative part consisted of before-and-after design and the qualitative part consisted of descriptive design. Results: In 2017 (during selective testing/“before” period) out of the 2440 TB patients, 80 (3%) were diagnosed with Isoniazid and Rifampicin resistance patients;in contrast in 2018 (during UDST/“after” period) of the 5129 TB patients 258 (5%) were diagnosed with Isoniazid and Rifampicin resistance. However, the proportion of eligible patients tested for rifampicin resistance during the “after” period was 60% when compared to 100% during the “before” period and median turnaround time for testing was also longer during the “after” period when compared to the “before” period (32.5 days vs 27.5 days). Major reasons for these two gaps were found to be difficulties in collecting sputum specimens and transportation. Conclusion: The rollout of UDST has led to a three-fold increase in a number of DR-TB cases detected in the region. There is a need for the programme to increase the proportion tested for DST by increasing the laboratory capacity and address the challenges in sputum collection and transportation.展开更多
The gram-negative bacterium Helicobacter pylori(H.pylori)causes chronic gastritis,gastric and duodenal ulcers,gastric cancer and mucosa-associated lymphoid tissue lymphoma.Treatment is recommended in all symptomatic p...The gram-negative bacterium Helicobacter pylori(H.pylori)causes chronic gastritis,gastric and duodenal ulcers,gastric cancer and mucosa-associated lymphoid tissue lymphoma.Treatment is recommended in all symptomatic patients.The current treatment options for H.pylori infection are outlined in this review in light of the recent challenges in eradication success,largely due to the rapid emergence of antibiotic resistant strains of H.pylori.Antibiotic resistance is a constantly evolving process and numerous studies have shown that the prevalence of H.pylori antibiotic resistance varies significantly from country to country,and even between regions within the same country.In addition,recent data has shown that previous antibiotic use is associated with harbouring antibiotic resistant H.pylori.Local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy.Antimicrobial resistance is assessed by H.pylori culture and antimicrobial susceptibility testing.Recently developed molecular tests offer an attractive alternative to culture and allow for the rapid molecular genetic identification of H.pylori and resistance-associated mutations directly from biopsy samples or bacterial culture material.Accumulating evidence indicates that surveillance of antimicrobial resistance by susceptibility testing is feasible and necessary to inform clinicians in their choice of therapy for management of H.pylori infection.展开更多
The management of Helicobacter pylori(H. pylori) infection treatment differs from the common treatment protocol for other infectious diseases. Because culture-or molecular-guided approaches face several practical issu...The management of Helicobacter pylori(H. pylori) infection treatment differs from the common treatment protocol for other infectious diseases. Because culture-or molecular-guided approaches face several practical issues, such as the invasive procedures required to obtain gastric biopsy specimens and the lack of availability of routine laboratory testing in some places, H. pylori treatment includes the administration of two or three empirically selected antibiotics combined with a proton pump inhibitor rather than evidence-based eradication treatment. The efficacy of empirical therapy is decreasing, mostly due to increasing multiple resistance. Multiresistance to levofloxacin, clarithromycin, and metronidazole, which are commonly used in empirical treatments, appears to have increased in many countries. Mutations play a primary role in the antimicrobial resistance of H. pylori, but many different mechanisms can be involved in the development of antibiotic resistance. Determining and understanding these possible mechanisms might allow the development of new methods for the detection of H. pylori and the determination of antimicrobial resistance. A treatment based on the detection of antimicrobial resistance is usually more effective than empirical treatment. Nevertheless, such an approach before treatment is still not recommended in the Maastricht guidelines due to the difficulty associated with the routine application of available cultureor molecular-based susceptibility tests, which are usually administered in cases of treatment failure. The management of first and rescue treatments requires further research due to the steadily increase in antimicrobial resistance.展开更多
The polymyxins are important antimicrobial agents against antibiotic-resistant gram-negative bacilli.In 2020,the Clinical and Laboratory Standards Institute modified the clinical breakpoints for polymyxin susceptibili...The polymyxins are important antimicrobial agents against antibiotic-resistant gram-negative bacilli.In 2020,the Clinical and Laboratory Standards Institute modified the clinical breakpoints for polymyxin susceptibility test by eliminating the"susceptible"interpretive category,only reporting intermediate(≤2 mg/L)and resistant(≥4 mg/L).However,the European Committee on Antimicrobial Susceptibility Testing recommended the use of clinical breakpoints of W2 mg/L as susceptible and>2 mg/L as resistant.The first-line laboratorians and clinicians in China have been perplexed by the inconsistence of international polymyxin clinical breakpoints and discouraged by the difficulty of conducting polymyxin susceptibility testing.Therefore,it is urgently needed to make it clear for the laboratorians in China to know how to accurately carry out polymyxin susceptibility testing and standardize the interpretation of susceptibility testing results.To this end,the experts from relevant fields were convened to formulate this consensus statement on the testing and clinical interpretation of polymyxin susceptibility.Relevant recommendations are proposed accordingly for laboratorians and clinicians to streamline their daily work.展开更多
The antibacterial activity of beta-lactam antibiotics or their combinations with inhibitor sulbactum against non-lactamase-producing strains,lactamase-producing and ESBLs-producing isolates was evaluated with twofold ...The antibacterial activity of beta-lactam antibiotics or their combinations with inhibitor sulbactum against non-lactamase-producing strains,lactamase-producing and ESBLs-producing isolates was evaluated with twofold dilution method after pathogens isolated from pigs and chickens were detected,respectively,for beta-lactamase and extended-spectrum beta-lactamases(ESBLs),The results revealed that most of 43 clinically isolated strains could produce beta-lactamase and 3 strains of shigella isolated from chicken samples produced ESBLs.All of 30 lactamase-producing strains isolated and only one of 16 non-lactamase-producing strains were resistant to amoxicillin and ampicillin.MICs of ampicillin against lactamaseproducing isolates decreased 10-40 and 10-20 times respectively,when it was conbined with sulbactam at ration of 1:2 and 1:4.All clinical isolates were susceptible to third-generation cephalosporins.The MICs of third-generation cephalosporins against lactamase-producing isolates did not change when they were conbined with sulbactam.MICs of ceftiofur and ceftriaxone against ESBLs-producing isolates decreased 2-4 times when they were conbined with sulbactam.展开更多
The volatile oil of Artemisia argyi was extracted by ultrasonic assisted extraction, and the extraction rate of volatile oil was 0.68%. Thevolatile oil of A. argyi was emulsified with 1% Tween-80, and drug susceptibil...The volatile oil of Artemisia argyi was extracted by ultrasonic assisted extraction, and the extraction rate of volatile oil was 0.68%. Thevolatile oil of A. argyi was emulsified with 1% Tween-80, and drug susceptibility test was conducted with avian Escherichia coli. The results showedthat the volatile oil of A. argyi had antibacterial effect against avian E. coli, and the minimal inhibitory concentration was 50 mg/mL. Taking sixcommon antibiotics as the control, drug susceptibility test was conducted with volatile oil of A. argyi. The results showed that 10 strains of E. coliwere sensitive to the volatile oil of A. argyi, three of which had different degrees of resistance and one had the tendency of resistance.展开更多
This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia. Pathogenic bacteria from hepatopancreas of the diseased P. clarkia were examined using convention...This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia. Pathogenic bacteria from hepatopancreas of the diseased P. clarkia were examined using conventional methods,and then were isolated. The further tests and analysis of the isolated strain were developed,including the regression experiment to P. clarkia,the morphology,physiological and biochemical characteristics,sequence analysis of their 16 S rRNA and gyr B genes,and the susceptibility test to antibiotics. Large colonies with similar morphology and color were obtained. Strain X120523 was identified as Citrobacter freundii,proved to have strong pathogenicity,and was susceptible to quinolones and aminoglycosides.展开更多
In order to isolate and identify the pathogenic bacteria causing dead chickens in a chicken farm in Qinhuangdao area,the liver,heart and other organs of dead chickens suspected of salmonella disease were collected ase...In order to isolate and identify the pathogenic bacteria causing dead chickens in a chicken farm in Qinhuangdao area,the liver,heart and other organs of dead chickens suspected of salmonella disease were collected aseptically,and streaked on SS agar medium and chromagar medium.Transparent colonies were observed on SS agar medium,and purple and transparent colonies on CAS medium.The isolate was conducted purification,staining microscopy,biochemical tests,and 16 S rRNA sequence analysis,and the results showed that four strains of the isolated bacte-ria were salmonella.The 16 S rRNA sequence analysis of four strains of salmonella showed that the isolates shared more than 99%homology.Drug susceptibility test was performed using paper method,and the results showed that most of the strains were resistant to tilmicosin,cefradine and sul-famethoxazole,but were sensitive to ceftriaxone.展开更多
[Objective]The paper was to determine the pathogen causing fox pneumonia in a breeding factory in Changli County.[Method]Through autopsy,a dominant strain was isolated from the lung of dead foxes,which was then perfor...[Objective]The paper was to determine the pathogen causing fox pneumonia in a breeding factory in Changli County.[Method]Through autopsy,a dominant strain was isolated from the lung of dead foxes,which was then performed Gram staining,16 S rRNA sequence analysis and biochemical identification.[Result]The strain was negative in Gram staining,and was identified as E.coli through 16 S rRNA sequence analysis and biochemical identification.Drug susceptibility test was conducted using 15 kinds of drug susceptibility papers.The E.coli was sensitive to florfenicol,enrofloxacin,ceftriaxone,norfloxacin;intermediately sensitive to amikacin,gentamicin;and strongly resistant to penicillin,ampicillin,cefradine,sulfamethoxazole,lincomycin,streptomycin and amoxicillin.[Conclusion]It is difficult to treat E.coli causing fox pneumonia with traditional antibiotics clinically.展开更多
Background: Typhoid disease remains a major public health problem globally, especially in developing countries in sub-Saharan Africa. Symptoms associated with typhoid disease mimic those of other febrile illnesses and...Background: Typhoid disease remains a major public health problem globally, especially in developing countries in sub-Saharan Africa. Symptoms associated with typhoid disease mimic those of other febrile illnesses and are thus difficult to make an accurate diagnosis. A confirmed diagnosis requires the determination or isolation of the bacteria in well-equipped laboratories. Developing countries are faced with a huge limitation of the laboratory infrastructure to diagnose typhoid disease, which would otherwise guide in treating, managing, controlling, and halting the spread of drug resistant mutants. Objective: This study, therefore, was aimed at determining the clinical presentation, performance of diagnostic tests and antibiotic susceptibility testing of Salmonella among adults attending Kangema Sub-County Hospital. Study Population: The study population was residents of Kangema Sub-County in Murang’a County, Kenya while the target population was adults. Methods: The study adopted a cross-sectional study design that employed a systematic random sampling procedure. The study took place between April and June 2021. The sample size was 97 respondents who all consented and were enrolled in the study. Interviewing the respondents was carried out by administering structured questionnaires to collect quantitative data. Stool samples were obtained and cultured in Cary Blair transport media and then cultured in appropriate media at the Murang’a County Referral Hospital Laboratory. A rapid Salmonella Antigen (SAT) test was also performed on all the stool samples. Data Analyses: Word Statistics and Data (STATA) v 13 was used for statistical analysis. Results: The prevalence of Typhoid Fever was at 6.2% (95% CI) which included S. Typhi (n = 1;16.7%) and S. Paratyphi B (n = 5;83.3%). No isolate showed resistance to Ciprofloxacin. The sensitivity of SAT is 100% and a specificity of 98.9% with a kappa statistic of almost perfect agreement (0.9641) with culture. Patients who had fever p = 0.001, abdominal distention p = 0.028, diarrhoea p = 0.038, loose or watery stool p = 0.021 and mild general condition p = 0.02 remained independently associated with Salmonella infection. Conclusion: Typhoid Fever being endemic, laboratory diagnosis was a key for confirmation after clinical diagnosis. SAT can accurately be used to detect the disease where culture is unavailable. However, antibiotic sensitivity tests were crucial when determining the drug of choice as Salmonella isolates were multi-drug resistant. Establishment of prescribing antimicrobial policies and guidelines can periodically monitor the antibiogram patterns.展开更多
Antimicrobial resistance(AMR)is a global public health issue.Rapid and accurate antimicrobial susceptibility tests(AST)on bacteria isolates would facilitate appropriate choice of antibiotics,in which patients receive ...Antimicrobial resistance(AMR)is a global public health issue.Rapid and accurate antimicrobial susceptibility tests(AST)on bacteria isolates would facilitate appropriate choice of antibiotics,in which patients receive appropriate treatment and the emergence of multidrug-resistant organisms could be prevented simultaneously.In this study,we have developed a microfluidic device named Self Dilution for Faster Antimicrobial Susceptibility Testing(SDFAST).This SlipChip-based device consists of two layers of microchips,allowing injection of bacterial suspension and antibiotics by simply connecting the two chips.By slipping one microchip against another in a single press of the microchip,the antibiotics can be diluted within seconds and be well mixed with bacterial samples.By combining SDFAST with a water-soluble tetrazolium salt-8(WST-8)assay,a range of clinically prevalent bacteria,including Acinetobacter baumannii,Escherichia coli,Klebsiella pneumoniae,and Staphylococci species,were tested under various antibiotics.Color analysis after 4–6 h of incubation showed an abrupt change in the WST-8 color of certain wells with diluted antibiotics,proving that instrument-free and immediate identification of minimum inhibitory concentration(MIC)could be achieved.The testing on 51 clinical isolates had an agreement of 92%,proving the accuracy of our method.These results validated its advantages of simple operation,rapid testing,and low sample consumption comparing to conventional methods,which require 16–24 h of incubation.Therefore,our method shows great potential to be further developed into a medical instrument for automated medical testing and point-of-care diagnosis.展开更多
Although various strategies have been proposed for enrichment of circulating tumor cells(CTCs),the clinical outcomes of CTC detection are far from satisfactory.The prevailingmethodologies for CTC detection are general...Although various strategies have been proposed for enrichment of circulating tumor cells(CTCs),the clinical outcomes of CTC detection are far from satisfactory.The prevailingmethodologies for CTC detection are generally oriented towardnaturallyoccurring targets;however,misdetection and interference are prevalent due to the diverse phenotypes and subpopulations of CTCs,which are highly heterogeneous.Here,a CTC isolation system based on the“labelcapture-release”process is demonstrated for the precise and highly efficient enrichment of CTCs fromclinical blood samples.On the basis of the abnormal glycometabolism of tumor cells,the surface of CTCs can be decorated with artificial azido groups.By utilizing bio-orthogonal plates designed with dibenzocyclooctane(DBCO)and disulfide groups,withthe aid of anti-fouling effects,CTCs labeled with azido groups can be captured through a copper-free click reaction and subsequently released via disulfide reduction.The technique has been shown to label tumor cells with the epithelial cell adhesion molecule(EpCAM)+and EpCAM~phenotypes in both adherent and suspended states.Moreover,it effectively isolates all epithelial,interstitial,and hybrid phenotypes of CTCs from clinical blood samples collected from dozens of patients across more than 10 cancer types.Compared to the clinically approved CTC detection system,our strategy demonstrates superior performance from the perspective of broad-spectrum and accurate recognition of heterogeneous CTCs.More importantly,most of the captured CTCs can be released with the retention of living activity,making this technique well suited for downstream applications such as drug susceptibility tests involving viable CTCs.展开更多
Background Drug susceptibility assay is very important in tuberculosis therapy. Pyrazinamide is a first line antituberculosis drug and diagnosis of its resistance in Mycobacterium tuberculosis （M. tuberculosis） is d...Background Drug susceptibility assay is very important in tuberculosis therapy. Pyrazinamide is a first line antituberculosis drug and diagnosis of its resistance in Mycobacterium tuberculosis （M. tuberculosis） is difficult and time consuming by conventional methods. In this study, we aimed to evaluate the performance of the microscopic observation drug susceptibility （MODS） assay in the detection of pyrazinamide resistance in M. tuberculosis relative to the conventional Wayne assay and Lowenstein-Jensen （L J） proportion method. Methods M. tuberculosis clinical isolates （n=132） were tested by the MODS and the Wayne assay： the results were compared with those obtained by the LJ proportion method. Mutations in the gene were identified by direct sequencing of the pncA genes of all isolates in which pyrazinamide resistance was detected by any of the three methods. Results Compared to the LJ results, the sensitivity and specificity of the MODS assay were 97.8% and 96.5% respectively; the sensitivity and specificity of the Wayne assay were 87.0% and 97.7% respectively. Mutations in the pncA gene were found in 41 of 46 strains that were pyrazinamide resistant （3 tests）, in 1 of the 4 strains （LJ only）, in 42 of 48 strains （at least I test）, but no mutations in 1 strain sensitive according to the MODS assay only. The MODS assay, Wayne assay and LJ proportion method provided results in a median time of 6, 7 and 26 days respectively. Conclusions MODS assay offers a rapid, simple and reliable method for the detection of pyrazinamide resistance in M. tuberculosis and is an optimal alternative method in resource limited countries.展开更多
Antimicrobial susceptibility tests(ASTs)are pivotal in combating multidrug resistant pathogens,yet they can be time‐consuming,labor‐intensive,and unstable.Using the AST of tigecycline for sepsis as the main model,he...Antimicrobial susceptibility tests(ASTs)are pivotal in combating multidrug resistant pathogens,yet they can be time‐consuming,labor‐intensive,and unstable.Using the AST of tigecycline for sepsis as the main model,here we establish an automated system of Clinical Antimicrobials Susceptibility Test Ramanometry(CAST‐R),based on D2O‐probed Raman microspectroscopy.Featuring a liquid robot for sample pretreatment and a machine learning‐based control scheme for data acquisition and quality control,the 3‐h,automated CAST‐R process accelerates AST by>10‐fold,processes 96 paralleled antibiotic‐exposure reactions,and produces high‐quality Raman spectra.The Expedited Minimal Inhibitory Concentration via Metabolic Activity is proposed as a quantitative and broadly applicable parameter for metabolism‐based AST,which shows 99%essential agreement and 93%categorical agreement with the broth microdilution method(BMD)when tested on 100 Acinetobacter baumannii isolates.Further tests on 26 clinically positive blood samples for eight antimicrobials,including tigecycline,meropenem,ceftazidime,ampicillin/sulbactam,oxacillin,clindamycin,vancomycin,and levofloxacin reveal 93%categorical agreement with BMD‐based results.The automation,speed,reliability,and general applicability of CAST‐R suggest its potential utility for guiding the clinical administration of antimicrobials.展开更多
The performance of antimicrobial susceptibility testing(AST)of bacteria and the interpretation of AST results for bacteria isolated from animals are complex tasks which must be performed using standard published metho...The performance of antimicrobial susceptibility testing(AST)of bacteria and the interpretation of AST results for bacteria isolated from animals are complex tasks which must be performed using standard published methodology and overseen by experts in clinical microbiology and in consultation with clinical pharmacologists.Otherwise,AST has significant potential for errors and mistakes.In this review,we provide guidance on how to correctly perform AST of bacteria isolated from animals and interpret the AST results.Particular emphasis is placed on the various approved or published methodologies for the different bacteria as well as the application of interpretive criteria,including clinical breakpoints and epidemiological cut-off values(ECVs/ECOFFs).Application of approved interpretive criteria and definitions of susceptible,susceptible dose-dependent,nonsusceptible,intermediate,and resistant for clinical breakpoints as well as wild-type and non-wildtype for ECVs,are explained and the difficulties resulting from the lack of approved clinical breakpoints for other bacteria,indications,and animal species is discussed.The requirement of quality controls in any AST approach is also emphasized.In addition,important parameters,often used in monitoring and surveillance studies,such as MIC50,MIC90,and testing range,are explained and criteria for the classification of bacteria as multidrug-resistant,extensively drug-resistant or pandrug-resistant are provided.Common mistakes are presented and the means to avoid them are described.To provide the most accurate AST,one must strictly adhere to approved standards or validated methodologies,like those of the Clinical and Laboratory Standards Institute or other internationally accepted AST documents and the detailed information provided therein.展开更多
Urinary tract infection with mixed microorganisms may lead to false-positive resistance detection.Current antimicrobial susceptibility testing(AST)performed in clinical laboratories is based on bacterial culture and t...Urinary tract infection with mixed microorganisms may lead to false-positive resistance detection.Current antimicrobial susceptibility testing(AST)performed in clinical laboratories is based on bacterial culture and takes a long time for mixed bacterial infections.Here,we propose a machine learning-based single-cell metabolism inactivation concentration(ML-MIC)model to achieve rapid AST for mixed bacterial infections.Using E.coli and S.aureus as a demonstration of mixed bacteria,we performed feature extraction and multi-feature analysis on stimulated Raman scattering(SRS)images of bacteria with the ML-MIC model to determine the subtypes and AST of the mixed bacteria.Furthermore,we assessed the AST of mixed bacteria in urine and obtained single-cell metabolism inactivation concentration in only 3 h.Collectively,we demonstrated that SRS imaging of bacterial metabolism can be extended to mixed bacterial infection cases for rapid AST.展开更多
BACKGROUND Endofaster is an innovative technology that can be combined with upper gastrointestinal endoscopy(UGE)to perform gastric juice analysis and real-time detection of Helicobacter pylori(H.pylori).AIM To assess...BACKGROUND Endofaster is an innovative technology that can be combined with upper gastrointestinal endoscopy(UGE)to perform gastric juice analysis and real-time detection of Helicobacter pylori(H.pylori).AIM To assess the diagnostic performance of this technology and its impact on the management of H.pylori in the real-life clinical setting.METHODS Patients undergoing routine UGE were prospectively recruited.Biopsies were taken to assess gastric histology according to the updated Sydney system and for rapid urease test(RUT).Gastric juice sampling and analysis was performed using the Endofaster,and the diagnosis of H.pylori was based on real-time ammonium measurements.Histological detection of H.pylori served as the diagnostic gold standard for comparing Endofaster-based H.pylori diagnosis with RUT-based H.pylori detection.RESULTS A total of 198 patients were prospectively enrolled in an H.pylori diagnostic study by Endofasterbased gastric juice analysis(EGJA)during the UGE.Biopsies for RUT and histological assessment were performed on 161 patients(82 men and 79 women,mean age 54.8±19.2 years).H.pylori infection was detected by histology in 47(29.2%)patients.Overall,the sensitivity,specificity,accuracy,positive predictive value,and negative predictive value(NPV)for H.pylori diagnosis by EGJA were 91.5%,93.0%,92.6%,84.3%,and 96.4%,respectively.In patients on treatment with proton pump inhibitors,diagnostic sensitivity was reduced by 27.3%,while specificity and NPV were unaffected.EGJA and RUT were comparable in diagnostic performance and highly concordant in H.pylori detection(κ-value=0.85).CONCLUSION Endofaster allows for rapid and highly accurate detection of H.pylori during gastroscopy.This may guide taking additional biopsies for antibiotic susceptibility testing during the same procedure and then selecting an individually tailored eradication regimen.展开更多
Extremely low frequency (ELF) magnetic field susceptibility is an index of visual display unit (VDU) quality and performance. This paper provided field measured data on the susceptibility for a large variety of VDUs. ...Extremely low frequency (ELF) magnetic field susceptibility is an index of visual display unit (VDU) quality and performance. This paper provided field measured data on the susceptibility for a large variety of VDUs. A test rig was built to study the susceptibility of VDUs to magnetic fields at fundamental and third harmonic frequencies. It was found that the susceptibility level is largely dependent on refresh rate of the VDU and the orientation of the external ELF field. It was also found that the VDU susceptibility is significantly increased in the presence of harmonic frequency magnetic fields. About 30% of the tested samples have susceptibility levels higher than that stated in IEC 1000-4-8 standard.展开更多
Pyogenic infections are caused by various pathogens leading to pus formation and that can be attributed due to a wound either through accident or during surgery leading to infection spread. There are pathogenic strain...Pyogenic infections are caused by various pathogens leading to pus formation and that can be attributed due to a wound either through accident or during surgery leading to infection spread. There are pathogenic strains that are not uncommon in hospital settings like <i>Staphylococcus aureus</i>, <i>Klebsiella pneumoniae</i>, <i>Pseudomonas aeruginosa</i>, <i>Acinetobacter</i> etc., that are multidrug resistant (MDR) and are a cause of concern. The bacteriological profile in the pyogenic infections tends to be same but there is a vast difference with the antibiotic resistant patterns in different hospital settings. Hence, the aim was to study the antibiotic susceptibility profiles and Extended spectrum <i>β</i>eta Lactamases (ES<i>β</i>L) production in these pathogens. A prospective study was carried out in Silchar Medical College and Hospital Assam, India, over a four-month period from February to May 2021. The samples were processed using Blood and MacConkey’s agar. Further, these isolated pathogens were identified by standard morphological, cultural and biochemical tests. The antibiotic susceptibility test was conducted by Kirby Bauer disc diffusion method and ES<i>β</i>L production was detected by using combined disk diffusion test. It was observed that the identified pathogens had an incidence rate of 84.2% and further revealed that Gram negative had a higher incidence rate compared to Gram positive with 59.8%. The pathogens isolated from pus samples had a maximum of <i>Klebsiella sps</i> (19.64%) and the lowest was <i>E. coli</i> with 5.36%. Antibiotic susceptibility test (AST) of Gram-negative bacterial isolates showed the highest incidence with aztreonam (40.6%) and the lowest was observed in Piperacillin/Tazobactam with 7.5%. The only Gram positive was observed in our study, <i>Staphylococcus aureus</i> had the highest resistance in amikacin with 80% and interestingly, all the isolates were sensitive to Linezolid with 100%. There is a high rise and spreading with the multi-drug resistance (MDR) strains along with ES<i>β</i>L production and it was observed in our studies that these pathogens had an incidence rate of 18.5%. The highest was 58.1% in Pseudomonas sps. None of <i>Proteus sps</i> were found to be ES<i>β</i>L producers. To combat resistance, the irrational use of antibiotics should be avoided and surveillance of the rising multidrug species regularly helps in implementing better therapeutic options to reduce the morbidity and mortality.展开更多
基金Supported by Sichuan Tobacco Monopoly Bureau Project ( 200901009)~~
文摘[ Objective ] The paper was to isolate and identify Ralstonia solanacearum from white burley, and determine its susceptibility to 6 fungicides. [ Mcth- od] Using the combination method of semiselective medium （PCCG） and apolymerase chain reaction （PCR） technique, R. solanacearum in stalk of white burley from Dazhou City in Sichnan Province was isolated, and its biochemical type was identified. Through susceptibility test, the susceptibility of R. solanacearum to bismerthiazol, ethylicin, streptomycin, lime sulfur, 47% polylysine, 99% kojic acid was studied in laboratory. [Result] A total of 23 strains OfR. solanacearum were isolated, all belonging to biochemical type Ill. R. solanacearum obtained in the test were more susceptible to ethylicin, streptomycin and bismerthiazol, and ethylicin had good control effect against R. solanacearum with ECso of 0.086 ml/L. [ Conclusion ] The study provide theoretical basis for control of R. solanaceanon in white burley.
文摘Background: In India, tuberculosis (TB) is a major public health problem, and the advent of drug resistance TB (DR-TB) has worsened the situation. The Revised National TB Control Programme (RNTCP) has introduced universal drug susceptibility testing (UDST) for all diagnosed TB cases in 2018. We conducted this study to know the advantage of implementing UDST when compared to selective testing existent in 2017 on key diagnostic cascade parameters and to identify the challenges in the implementation of UDST. Methods: The study was conducted in two districts of Karnataka, India during January 2017-December 2018. The quantitative part consisted of before-and-after design and the qualitative part consisted of descriptive design. Results: In 2017 (during selective testing/“before” period) out of the 2440 TB patients, 80 (3%) were diagnosed with Isoniazid and Rifampicin resistance patients;in contrast in 2018 (during UDST/“after” period) of the 5129 TB patients 258 (5%) were diagnosed with Isoniazid and Rifampicin resistance. However, the proportion of eligible patients tested for rifampicin resistance during the “after” period was 60% when compared to 100% during the “before” period and median turnaround time for testing was also longer during the “after” period when compared to the “before” period (32.5 days vs 27.5 days). Major reasons for these two gaps were found to be difficulties in collecting sputum specimens and transportation. Conclusion: The rollout of UDST has led to a three-fold increase in a number of DR-TB cases detected in the region. There is a need for the programme to increase the proportion tested for DST by increasing the laboratory capacity and address the challenges in sputum collection and transportation.
文摘The gram-negative bacterium Helicobacter pylori(H.pylori)causes chronic gastritis,gastric and duodenal ulcers,gastric cancer and mucosa-associated lymphoid tissue lymphoma.Treatment is recommended in all symptomatic patients.The current treatment options for H.pylori infection are outlined in this review in light of the recent challenges in eradication success,largely due to the rapid emergence of antibiotic resistant strains of H.pylori.Antibiotic resistance is a constantly evolving process and numerous studies have shown that the prevalence of H.pylori antibiotic resistance varies significantly from country to country,and even between regions within the same country.In addition,recent data has shown that previous antibiotic use is associated with harbouring antibiotic resistant H.pylori.Local surveillance of antibiotic resistance is warranted to guide clinicians in their choice of therapy.Antimicrobial resistance is assessed by H.pylori culture and antimicrobial susceptibility testing.Recently developed molecular tests offer an attractive alternative to culture and allow for the rapid molecular genetic identification of H.pylori and resistance-associated mutations directly from biopsy samples or bacterial culture material.Accumulating evidence indicates that surveillance of antimicrobial resistance by susceptibility testing is feasible and necessary to inform clinicians in their choice of therapy for management of H.pylori infection.
文摘The management of Helicobacter pylori(H. pylori) infection treatment differs from the common treatment protocol for other infectious diseases. Because culture-or molecular-guided approaches face several practical issues, such as the invasive procedures required to obtain gastric biopsy specimens and the lack of availability of routine laboratory testing in some places, H. pylori treatment includes the administration of two or three empirically selected antibiotics combined with a proton pump inhibitor rather than evidence-based eradication treatment. The efficacy of empirical therapy is decreasing, mostly due to increasing multiple resistance. Multiresistance to levofloxacin, clarithromycin, and metronidazole, which are commonly used in empirical treatments, appears to have increased in many countries. Mutations play a primary role in the antimicrobial resistance of H. pylori, but many different mechanisms can be involved in the development of antibiotic resistance. Determining and understanding these possible mechanisms might allow the development of new methods for the detection of H. pylori and the determination of antimicrobial resistance. A treatment based on the detection of antimicrobial resistance is usually more effective than empirical treatment. Nevertheless, such an approach before treatment is still not recommended in the Maastricht guidelines due to the difficulty associated with the routine application of available cultureor molecular-based susceptibility tests, which are usually administered in cases of treatment failure. The management of first and rescue treatments requires further research due to the steadily increase in antimicrobial resistance.
基金the National Key Research&Development Program(2018YFC1200100,2018YFC1200105)the Major Research and Development Project of Innovative Drugs,Ministry of Science and Technology of China(2017ZX09304005).
文摘The polymyxins are important antimicrobial agents against antibiotic-resistant gram-negative bacilli.In 2020,the Clinical and Laboratory Standards Institute modified the clinical breakpoints for polymyxin susceptibility test by eliminating the"susceptible"interpretive category,only reporting intermediate(≤2 mg/L)and resistant(≥4 mg/L).However,the European Committee on Antimicrobial Susceptibility Testing recommended the use of clinical breakpoints of W2 mg/L as susceptible and>2 mg/L as resistant.The first-line laboratorians and clinicians in China have been perplexed by the inconsistence of international polymyxin clinical breakpoints and discouraged by the difficulty of conducting polymyxin susceptibility testing.Therefore,it is urgently needed to make it clear for the laboratorians in China to know how to accurately carry out polymyxin susceptibility testing and standardize the interpretation of susceptibility testing results.To this end,the experts from relevant fields were convened to formulate this consensus statement on the testing and clinical interpretation of polymyxin susceptibility.Relevant recommendations are proposed accordingly for laboratorians and clinicians to streamline their daily work.
基金supported by the National Natural Science Foundation of China(30471307).
文摘The antibacterial activity of beta-lactam antibiotics or their combinations with inhibitor sulbactum against non-lactamase-producing strains,lactamase-producing and ESBLs-producing isolates was evaluated with twofold dilution method after pathogens isolated from pigs and chickens were detected,respectively,for beta-lactamase and extended-spectrum beta-lactamases(ESBLs),The results revealed that most of 43 clinically isolated strains could produce beta-lactamase and 3 strains of shigella isolated from chicken samples produced ESBLs.All of 30 lactamase-producing strains isolated and only one of 16 non-lactamase-producing strains were resistant to amoxicillin and ampicillin.MICs of ampicillin against lactamaseproducing isolates decreased 10-40 and 10-20 times respectively,when it was conbined with sulbactam at ration of 1:2 and 1:4.All clinical isolates were susceptible to third-generation cephalosporins.The MICs of third-generation cephalosporins against lactamase-producing isolates did not change when they were conbined with sulbactam.MICs of ceftiofur and ceftriaxone against ESBLs-producing isolates decreased 2-4 times when they were conbined with sulbactam.
基金Supported by Scientific Research and Technology Development Program of Guangxi ProvinceConstruction of Science and Technology Service Platform in Hezhou Agricultural Science and Tech-nology Park(GKN 14258003)Scientific Research Project of Hezhou University(HZU-JS201617)
文摘The volatile oil of Artemisia argyi was extracted by ultrasonic assisted extraction, and the extraction rate of volatile oil was 0.68%. Thevolatile oil of A. argyi was emulsified with 1% Tween-80, and drug susceptibility test was conducted with avian Escherichia coli. The results showedthat the volatile oil of A. argyi had antibacterial effect against avian E. coli, and the minimal inhibitory concentration was 50 mg/mL. Taking sixcommon antibiotics as the control, drug susceptibility test was conducted with volatile oil of A. argyi. The results showed that 10 strains of E. coliwere sensitive to the volatile oil of A. argyi, three of which had different degrees of resistance and one had the tendency of resistance.
基金Supported by the Science and Technology Innovative Research Team of Anhui Academy of Agricultural Sciences(14C0504)the Youth Innovation Foundation of President of Anhui Academy of Agricultural Sciences(14B0529)Anhui Aquaculture Industry Technology System for Shrimp and Crab
文摘This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia. Pathogenic bacteria from hepatopancreas of the diseased P. clarkia were examined using conventional methods,and then were isolated. The further tests and analysis of the isolated strain were developed,including the regression experiment to P. clarkia,the morphology,physiological and biochemical characteristics,sequence analysis of their 16 S rRNA and gyr B genes,and the susceptibility test to antibiotics. Large colonies with similar morphology and color were obtained. Strain X120523 was identified as Citrobacter freundii,proved to have strong pathogenicity,and was susceptible to quinolones and aminoglycosides.
基金Supported by The Third Batch Giant Plan of Hebei Province(180416H)
文摘In order to isolate and identify the pathogenic bacteria causing dead chickens in a chicken farm in Qinhuangdao area,the liver,heart and other organs of dead chickens suspected of salmonella disease were collected aseptically,and streaked on SS agar medium and chromagar medium.Transparent colonies were observed on SS agar medium,and purple and transparent colonies on CAS medium.The isolate was conducted purification,staining microscopy,biochemical tests,and 16 S rRNA sequence analysis,and the results showed that four strains of the isolated bacte-ria were salmonella.The 16 S rRNA sequence analysis of four strains of salmonella showed that the isolates shared more than 99%homology.Drug susceptibility test was performed using paper method,and the results showed that most of the strains were resistant to tilmicosin,cefradine and sul-famethoxazole,but were sensitive to ceftriaxone.
基金Supported by Project of Hebei Department of Science and Technology(18246629G)Project of Shijiazhuang Science and Technology Bureau(171500953A)Project of Hebei Department of Education(ZD2017234)
文摘[Objective]The paper was to determine the pathogen causing fox pneumonia in a breeding factory in Changli County.[Method]Through autopsy,a dominant strain was isolated from the lung of dead foxes,which was then performed Gram staining,16 S rRNA sequence analysis and biochemical identification.[Result]The strain was negative in Gram staining,and was identified as E.coli through 16 S rRNA sequence analysis and biochemical identification.Drug susceptibility test was conducted using 15 kinds of drug susceptibility papers.The E.coli was sensitive to florfenicol,enrofloxacin,ceftriaxone,norfloxacin;intermediately sensitive to amikacin,gentamicin;and strongly resistant to penicillin,ampicillin,cefradine,sulfamethoxazole,lincomycin,streptomycin and amoxicillin.[Conclusion]It is difficult to treat E.coli causing fox pneumonia with traditional antibiotics clinically.
文摘Background: Typhoid disease remains a major public health problem globally, especially in developing countries in sub-Saharan Africa. Symptoms associated with typhoid disease mimic those of other febrile illnesses and are thus difficult to make an accurate diagnosis. A confirmed diagnosis requires the determination or isolation of the bacteria in well-equipped laboratories. Developing countries are faced with a huge limitation of the laboratory infrastructure to diagnose typhoid disease, which would otherwise guide in treating, managing, controlling, and halting the spread of drug resistant mutants. Objective: This study, therefore, was aimed at determining the clinical presentation, performance of diagnostic tests and antibiotic susceptibility testing of Salmonella among adults attending Kangema Sub-County Hospital. Study Population: The study population was residents of Kangema Sub-County in Murang’a County, Kenya while the target population was adults. Methods: The study adopted a cross-sectional study design that employed a systematic random sampling procedure. The study took place between April and June 2021. The sample size was 97 respondents who all consented and were enrolled in the study. Interviewing the respondents was carried out by administering structured questionnaires to collect quantitative data. Stool samples were obtained and cultured in Cary Blair transport media and then cultured in appropriate media at the Murang’a County Referral Hospital Laboratory. A rapid Salmonella Antigen (SAT) test was also performed on all the stool samples. Data Analyses: Word Statistics and Data (STATA) v 13 was used for statistical analysis. Results: The prevalence of Typhoid Fever was at 6.2% (95% CI) which included S. Typhi (n = 1;16.7%) and S. Paratyphi B (n = 5;83.3%). No isolate showed resistance to Ciprofloxacin. The sensitivity of SAT is 100% and a specificity of 98.9% with a kappa statistic of almost perfect agreement (0.9641) with culture. Patients who had fever p = 0.001, abdominal distention p = 0.028, diarrhoea p = 0.038, loose or watery stool p = 0.021 and mild general condition p = 0.02 remained independently associated with Salmonella infection. Conclusion: Typhoid Fever being endemic, laboratory diagnosis was a key for confirmation after clinical diagnosis. SAT can accurately be used to detect the disease where culture is unavailable. However, antibiotic sensitivity tests were crucial when determining the drug of choice as Salmonella isolates were multi-drug resistant. Establishment of prescribing antimicrobial policies and guidelines can periodically monitor the antibiogram patterns.
基金supported by the Health@InnoHK program of the Innovation and Technology Commission of the Hong Kong SAR Governmentsupported by The University of Hong Kong(202009185087)+1 种基金Collaborative Research Fund(C7165-20GF)General Research Fund(17307919 and 17303123)of the Research Grants Council of Hong Kong,Hong Kong.
文摘Antimicrobial resistance(AMR)is a global public health issue.Rapid and accurate antimicrobial susceptibility tests(AST)on bacteria isolates would facilitate appropriate choice of antibiotics,in which patients receive appropriate treatment and the emergence of multidrug-resistant organisms could be prevented simultaneously.In this study,we have developed a microfluidic device named Self Dilution for Faster Antimicrobial Susceptibility Testing(SDFAST).This SlipChip-based device consists of two layers of microchips,allowing injection of bacterial suspension and antibiotics by simply connecting the two chips.By slipping one microchip against another in a single press of the microchip,the antibiotics can be diluted within seconds and be well mixed with bacterial samples.By combining SDFAST with a water-soluble tetrazolium salt-8(WST-8)assay,a range of clinically prevalent bacteria,including Acinetobacter baumannii,Escherichia coli,Klebsiella pneumoniae,and Staphylococci species,were tested under various antibiotics.Color analysis after 4–6 h of incubation showed an abrupt change in the WST-8 color of certain wells with diluted antibiotics,proving that instrument-free and immediate identification of minimum inhibitory concentration(MIC)could be achieved.The testing on 51 clinical isolates had an agreement of 92%,proving the accuracy of our method.These results validated its advantages of simple operation,rapid testing,and low sample consumption comparing to conventional methods,which require 16–24 h of incubation.Therefore,our method shows great potential to be further developed into a medical instrument for automated medical testing and point-of-care diagnosis.
基金supported by the National Key R&D Program of China(2021YFB3800800)the National Natural Science Foundation of China(81903057,82073284,32000962,82402491,and 82272157)+2 种基金Shenzhen Science and Technology Research Funding(JCYJ20200109115601720)the Hong Kong PDFS-RGC Postdoctoral Fellowship Scheme(PDFS2122-1S08 and CityU 9061014)Hong Kong HMRF(Health and Medical Research Fund)(2120972 and CityU 9211320)。
文摘Although various strategies have been proposed for enrichment of circulating tumor cells(CTCs),the clinical outcomes of CTC detection are far from satisfactory.The prevailingmethodologies for CTC detection are generally oriented towardnaturallyoccurring targets;however,misdetection and interference are prevalent due to the diverse phenotypes and subpopulations of CTCs,which are highly heterogeneous.Here,a CTC isolation system based on the“labelcapture-release”process is demonstrated for the precise and highly efficient enrichment of CTCs fromclinical blood samples.On the basis of the abnormal glycometabolism of tumor cells,the surface of CTCs can be decorated with artificial azido groups.By utilizing bio-orthogonal plates designed with dibenzocyclooctane(DBCO)and disulfide groups,withthe aid of anti-fouling effects,CTCs labeled with azido groups can be captured through a copper-free click reaction and subsequently released via disulfide reduction.The technique has been shown to label tumor cells with the epithelial cell adhesion molecule(EpCAM)+and EpCAM~phenotypes in both adherent and suspended states.Moreover,it effectively isolates all epithelial,interstitial,and hybrid phenotypes of CTCs from clinical blood samples collected from dozens of patients across more than 10 cancer types.Compared to the clinically approved CTC detection system,our strategy demonstrates superior performance from the perspective of broad-spectrum and accurate recognition of heterogeneous CTCs.More importantly,most of the captured CTCs can be released with the retention of living activity,making this technique well suited for downstream applications such as drug susceptibility tests involving viable CTCs.
基金This study was supported by grants from the National Natural Science Foundation of China （No. 81060001 ） and the Foundation of Scientific ＆ Technical Research Project of Jiangxi Province （No. 2009BSB11219）.
文摘Background Drug susceptibility assay is very important in tuberculosis therapy. Pyrazinamide is a first line antituberculosis drug and diagnosis of its resistance in Mycobacterium tuberculosis （M. tuberculosis） is difficult and time consuming by conventional methods. In this study, we aimed to evaluate the performance of the microscopic observation drug susceptibility （MODS） assay in the detection of pyrazinamide resistance in M. tuberculosis relative to the conventional Wayne assay and Lowenstein-Jensen （L J） proportion method. Methods M. tuberculosis clinical isolates （n=132） were tested by the MODS and the Wayne assay： the results were compared with those obtained by the LJ proportion method. Mutations in the gene were identified by direct sequencing of the pncA genes of all isolates in which pyrazinamide resistance was detected by any of the three methods. Results Compared to the LJ results, the sensitivity and specificity of the MODS assay were 97.8% and 96.5% respectively; the sensitivity and specificity of the Wayne assay were 87.0% and 97.7% respectively. Mutations in the pncA gene were found in 41 of 46 strains that were pyrazinamide resistant （3 tests）, in 1 of the 4 strains （LJ only）, in 42 of 48 strains （at least I test）, but no mutations in 1 strain sensitive according to the MODS assay only. The MODS assay, Wayne assay and LJ proportion method provided results in a median time of 6, 7 and 26 days respectively. Conclusions MODS assay offers a rapid, simple and reliable method for the detection of pyrazinamide resistance in M. tuberculosis and is an optimal alternative method in resource limited countries.
基金We thank Yang Liu for graphics support.This study was supported by CAS(XDB29050400,KFJ‐STS‐QYZX‐087)NSFC(31827801,82072318)+1 种基金National Key Research and Development Program of China(2018YFE0101800,2021YFC2301002)Traditional Chinese Medicine Science and Technology Development Program of Shandong Province(No.2019‐0596).
文摘Antimicrobial susceptibility tests(ASTs)are pivotal in combating multidrug resistant pathogens,yet they can be time‐consuming,labor‐intensive,and unstable.Using the AST of tigecycline for sepsis as the main model,here we establish an automated system of Clinical Antimicrobials Susceptibility Test Ramanometry(CAST‐R),based on D2O‐probed Raman microspectroscopy.Featuring a liquid robot for sample pretreatment and a machine learning‐based control scheme for data acquisition and quality control,the 3‐h,automated CAST‐R process accelerates AST by>10‐fold,processes 96 paralleled antibiotic‐exposure reactions,and produces high‐quality Raman spectra.The Expedited Minimal Inhibitory Concentration via Metabolic Activity is proposed as a quantitative and broadly applicable parameter for metabolism‐based AST,which shows 99%essential agreement and 93%categorical agreement with the broth microdilution method(BMD)when tested on 100 Acinetobacter baumannii isolates.Further tests on 26 clinically positive blood samples for eight antimicrobials,including tigecycline,meropenem,ceftazidime,ampicillin/sulbactam,oxacillin,clindamycin,vancomycin,and levofloxacin reveal 93%categorical agreement with BMD‐based results.The automation,speed,reliability,and general applicability of CAST‐R suggest its potential utility for guiding the clinical administration of antimicrobials.
文摘The performance of antimicrobial susceptibility testing(AST)of bacteria and the interpretation of AST results for bacteria isolated from animals are complex tasks which must be performed using standard published methodology and overseen by experts in clinical microbiology and in consultation with clinical pharmacologists.Otherwise,AST has significant potential for errors and mistakes.In this review,we provide guidance on how to correctly perform AST of bacteria isolated from animals and interpret the AST results.Particular emphasis is placed on the various approved or published methodologies for the different bacteria as well as the application of interpretive criteria,including clinical breakpoints and epidemiological cut-off values(ECVs/ECOFFs).Application of approved interpretive criteria and definitions of susceptible,susceptible dose-dependent,nonsusceptible,intermediate,and resistant for clinical breakpoints as well as wild-type and non-wildtype for ECVs,are explained and the difficulties resulting from the lack of approved clinical breakpoints for other bacteria,indications,and animal species is discussed.The requirement of quality controls in any AST approach is also emphasized.In addition,important parameters,often used in monitoring and surveillance studies,such as MIC50,MIC90,and testing range,are explained and criteria for the classification of bacteria as multidrug-resistant,extensively drug-resistant or pandrug-resistant are provided.Common mistakes are presented and the means to avoid them are described.To provide the most accurate AST,one must strictly adhere to approved standards or validated methodologies,like those of the Clinical and Laboratory Standards Institute or other internationally accepted AST documents and the detailed information provided therein.
基金the National Natural Science Foundation of China(81901790)the Key R&D program of Ministry of Science and Technology(2020YFC2005405)Beijing Natural Science Foundation(No.7224367 to X.Chen).
文摘Urinary tract infection with mixed microorganisms may lead to false-positive resistance detection.Current antimicrobial susceptibility testing(AST)performed in clinical laboratories is based on bacterial culture and takes a long time for mixed bacterial infections.Here,we propose a machine learning-based single-cell metabolism inactivation concentration(ML-MIC)model to achieve rapid AST for mixed bacterial infections.Using E.coli and S.aureus as a demonstration of mixed bacteria,we performed feature extraction and multi-feature analysis on stimulated Raman scattering(SRS)images of bacteria with the ML-MIC model to determine the subtypes and AST of the mixed bacteria.Furthermore,we assessed the AST of mixed bacteria in urine and obtained single-cell metabolism inactivation concentration in only 3 h.Collectively,we demonstrated that SRS imaging of bacterial metabolism can be extended to mixed bacterial infection cases for rapid AST.
基金Supported by the Deutsches Zentrum für Infektionsforschung,Partner Site Munich,Germany,No.TTU 06.715_00the Bavarian Ministry of Science and the Arts within the framework of the Bavarian Research Network“New Strategies Against Multi-Resistant Pathogens by Means of Digital Networking–bayresq.net”.
文摘BACKGROUND Endofaster is an innovative technology that can be combined with upper gastrointestinal endoscopy(UGE)to perform gastric juice analysis and real-time detection of Helicobacter pylori(H.pylori).AIM To assess the diagnostic performance of this technology and its impact on the management of H.pylori in the real-life clinical setting.METHODS Patients undergoing routine UGE were prospectively recruited.Biopsies were taken to assess gastric histology according to the updated Sydney system and for rapid urease test(RUT).Gastric juice sampling and analysis was performed using the Endofaster,and the diagnosis of H.pylori was based on real-time ammonium measurements.Histological detection of H.pylori served as the diagnostic gold standard for comparing Endofaster-based H.pylori diagnosis with RUT-based H.pylori detection.RESULTS A total of 198 patients were prospectively enrolled in an H.pylori diagnostic study by Endofasterbased gastric juice analysis(EGJA)during the UGE.Biopsies for RUT and histological assessment were performed on 161 patients(82 men and 79 women,mean age 54.8±19.2 years).H.pylori infection was detected by histology in 47(29.2%)patients.Overall,the sensitivity,specificity,accuracy,positive predictive value,and negative predictive value(NPV)for H.pylori diagnosis by EGJA were 91.5%,93.0%,92.6%,84.3%,and 96.4%,respectively.In patients on treatment with proton pump inhibitors,diagnostic sensitivity was reduced by 27.3%,while specificity and NPV were unaffected.EGJA and RUT were comparable in diagnostic performance and highly concordant in H.pylori detection(κ-value=0.85).CONCLUSION Endofaster allows for rapid and highly accurate detection of H.pylori during gastroscopy.This may guide taking additional biopsies for antibiotic susceptibility testing during the same procedure and then selecting an individually tailored eradication regimen.
文摘Extremely low frequency (ELF) magnetic field susceptibility is an index of visual display unit (VDU) quality and performance. This paper provided field measured data on the susceptibility for a large variety of VDUs. A test rig was built to study the susceptibility of VDUs to magnetic fields at fundamental and third harmonic frequencies. It was found that the susceptibility level is largely dependent on refresh rate of the VDU and the orientation of the external ELF field. It was also found that the VDU susceptibility is significantly increased in the presence of harmonic frequency magnetic fields. About 30% of the tested samples have susceptibility levels higher than that stated in IEC 1000-4-8 standard.
文摘Pyogenic infections are caused by various pathogens leading to pus formation and that can be attributed due to a wound either through accident or during surgery leading to infection spread. There are pathogenic strains that are not uncommon in hospital settings like <i>Staphylococcus aureus</i>, <i>Klebsiella pneumoniae</i>, <i>Pseudomonas aeruginosa</i>, <i>Acinetobacter</i> etc., that are multidrug resistant (MDR) and are a cause of concern. The bacteriological profile in the pyogenic infections tends to be same but there is a vast difference with the antibiotic resistant patterns in different hospital settings. Hence, the aim was to study the antibiotic susceptibility profiles and Extended spectrum <i>β</i>eta Lactamases (ES<i>β</i>L) production in these pathogens. A prospective study was carried out in Silchar Medical College and Hospital Assam, India, over a four-month period from February to May 2021. The samples were processed using Blood and MacConkey’s agar. Further, these isolated pathogens were identified by standard morphological, cultural and biochemical tests. The antibiotic susceptibility test was conducted by Kirby Bauer disc diffusion method and ES<i>β</i>L production was detected by using combined disk diffusion test. It was observed that the identified pathogens had an incidence rate of 84.2% and further revealed that Gram negative had a higher incidence rate compared to Gram positive with 59.8%. The pathogens isolated from pus samples had a maximum of <i>Klebsiella sps</i> (19.64%) and the lowest was <i>E. coli</i> with 5.36%. Antibiotic susceptibility test (AST) of Gram-negative bacterial isolates showed the highest incidence with aztreonam (40.6%) and the lowest was observed in Piperacillin/Tazobactam with 7.5%. The only Gram positive was observed in our study, <i>Staphylococcus aureus</i> had the highest resistance in amikacin with 80% and interestingly, all the isolates were sensitive to Linezolid with 100%. There is a high rise and spreading with the multi-drug resistance (MDR) strains along with ES<i>β</i>L production and it was observed in our studies that these pathogens had an incidence rate of 18.5%. The highest was 58.1% in Pseudomonas sps. None of <i>Proteus sps</i> were found to be ES<i>β</i>L producers. To combat resistance, the irrational use of antibiotics should be avoided and surveillance of the rising multidrug species regularly helps in implementing better therapeutic options to reduce the morbidity and mortality.
