Antimicrobial susceptibility testing for Helicobacter pylori in times of increasing antibiotic resistance

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.

Importance of antimicrobial susceptibility testing for the management of eradication in Helicobacter pylori infection

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.

Expert Consensus on Polymyxin Antimicrobial Susceptibility Testing and Clinical Interpretation

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.

A comparative study on antimicrobial susceptibility of uroculturome of humans in health and urinary tract infections

Background:The uroculturome indicates the profile of culturable microbes inhabiting the urinary tract,and it is often required to do a urine culture to find an effective antimicrobial to treat urinary tract infections(UTIs).Methods:This study targeted to understand the profile of culturable pathogens in the urine of apparently healthy(128)and humans with clinical UTIs(161)and their antimicrobial susceptibility.All the urine samples were analyzed to quantify microbial load and determine the diversity and antimicrobial susceptibility of microbes following standard microbiological methods.Results:In urine samples from UTI cases,microbial counts were 1.2×10^(4)±6.02×10^(3) colony-forming units(cfu)/mL,while in urine samples from apparently healthy humans,the average count was 3.33±1.34×10^(3) cfu/mL.In eight samples(six from UTI cases and two from apparently healthy people,Candida(C.albicans 3,C.catenulata 1,C.krusei 1,C.tropicalis 1,C.parapsiplosis 1,C.gulliermondii 1)and Rhizopus species(1)were detected.Candida krusei was detected only in a single urine sample from a healthy person and C.albicans was detected both in urine of healthy and clinical UTI cases.Gram-positive(G+ve)bacteria were more commonly(Odds ratio,1.98;CI99,1.01-3.87)detected in urine samples of apparently healthy humans,and Gram-negative(G−ve)bacteria(Odds ratio,2.74;CI99,1.44-5.23)in urines of UTI cases.From urine samples of 161 UTI cases,a total of 90 different types of microbes were detected and,73 samples had only a single type of bacteria.In contrast,49,29,3,4,1,and 2 samples had 2,3,4,5,6 and 7 types of bacteria,respectively.The most common bacteria detected in urine of UTI cases was Escherichia coli(52 samples),in 20 cases as the single type of bacteria,other 34 types of bacteria were detected in pure form in 53 cases.From 128 urine samples of apparently healthy people,88 types of microbes were detected either singly or in association with others,from 64 urine samples only a single type of bacteria was detected while 34,13,3,11,2 and 1 sample yielded 2,3,4,5,6 and seven types of microbes,respectively.In the urine of apparently healthy humans too,E.coli was the most common bacteria,(10 samples)followed by Staphylococcus haemolyticus(9),S.intermedius(5),and S.aureus(5),and similar types of bacteria also dominated in cases of mixed occurrence,E.coli was detected in 26,S.aureus in 22 and S.haemolyticus in 19 urine samples,respectively.G+ve bacteria isolated from urine samples’irrespective of health status were more often(P<0.01)resistant than G−ve bacteria to ajowan oil,holy basil oil,cinnamaldehyde,and cinnamon oil,but more susceptible to sandalwood oil(P<0.01).However,for antibiotics,G+ve were more often susceptible than G−ve bacteria to cephalosporins,doxycycline,and nitrofurantoin.Conclusion:The study concludes that to understand the role of good and bad bacteria in the urinary tract microbiome more targeted studies are needed to discern the isolates at the pathotype level.Further,the study suggests the use of antibiotics by observing good antibiotic stewardship following antibiotic susceptibility testing only.

Susceptibility of Mixed Infection of Ureaplasma Urealyticum and Mycoplasma Hominis to Seven Antimicrobial Agents and Comparison with that of Ureaplasma Urealyticum Infection

In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum (UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with that of UU infection in NGU patients, the in vitro susceptibility was determined by using microdilution method. The positive results were analyzed. The results showed that the sequence of susceptibility to 7 kinds of antimicrobial agents for both UU infection group and UU-MH mixed infection group was almost the same from the highest susceptibility to the lowest accordingly: Josamycin, Doxycycline, Minocycline, Sparfloxacin, Roxithromycin, Ofloxacin and Azithromycin. The total drug resistance rate for UU-MH mixed infection group (97. 67 %) was significantly higher than that for UU infection group (44. 67 %, P<.0. 01). The highest drug resistance rate in UU group and UU-MH mixed infection group was 31. 33 % (Ofloxacin) and 90. 48 % (Azithromycin) respectively. UU-MH mixed infection showed an increased drug resistance and changes of drug resistance spectrum.

Antimicrobial susceptibility patterns of Streptococcus pneumoniae over 6 years at Gondar University Hospital, Northwest Ethiopia

Objective:To assess the magnitude and antimicrobial susceptibility patterns ofStreptococcus pneumoniaeisolates from various clinical specimens.Methods:A record based on retrospectivestudy was conducted at Gondar University Teaching Hospital from September 2007 to January 2012.All patients who visited Gondar University Hospital and provided clinical specimens(body fluids,discharge,swab and blood)for routine bacteriological culturing and antimicrobial susceptibilitytesting were taken for analysis.Clinical specimens were processed for bacterial culture accordingto the standard procedures.Antimicrobial susceptibility test for isolated organisms was doneusing agar disk diffusion method.The data were entered and analyzed using SPSS software version16 package.Results:One hundred and fifty threeStreptococcus pneumoniaewere isolated frompatients who visited Gondar University Teaching Hospital bacteriology laboratory for culture.Majority of the pneumococcal isolates were from inpatients[111(72.5%)],and 74(48.4%)were frombody fluids.Out of the total isolates,93(61%)were found to be resistant to at least one antibioticused for susceptibility testing.Forty eight(43.2%)of the isolates were multi-drug resistant(resistantto two or more drugs).The resistance rate noted for both ciprofloxacin 17(11.1%)and ceftriaxone15(9.8%)were alarming.Conclusions:High proportions of the isolates tend to be increasinglyresistant to the commonly prescribed drugs.The recommended drug of choice like ciprofloxacinand ceftriaxone were found to be less susceptible in the study area.Based on the findings,wetherefore recommend that antimicrobial agents should be inspected for acceptable activity beforethey are prescribed and administered empirically.Further study with a better design and surveyof antimicrobial susceptibility at large scale shoule be performed to draw advanced information.

Antimicrobial Susceptibility Profiles among <i>Escherichia coli</i>Strains Isolated from Athi River Water in Machakos County, Kenya

Antimicrobial use in agriculture, livestock and human health has increased over the years leading to the increase in antimicrobial resistance that can also find its way to the aquatic environment. Rivers can act as reservoirs of highly resistant strains and facilitate the dissemination of multidrug resistant (MDR) strains to animals and humans using water. A total of 318 water samples were collected from six different sampling points along Athi River and E. coli isolates were subjected to Kirby-Bauer diffusion method for antimicrobial susceptibility testing. The total mean coliform count of the sampled sites was 2.7 × 104 (cfu/mL). E. coli isolates were most resistant to ampicillin (63.8%) and most susceptible to gentamicin (99.4%). MDR strains (resistance to ≥3 classes of antibiotics) accounted for 65.4% of all the isolates. The site recorded to have human industrial and agricultural zone activities had strains that were significantly more resistant to ampicillin, cefoxitin, amoxicillin/clavulanic acid (P ≤ 0.05) than isolates from the section of the river traversing virgin land and land with minimum human activities. This study indicates that E. coli strains isolated from Athi River were highly MDR and most resistant to some antimicrobial classes (ampicillin and cefoxitin) which constitute a potential risk to human and animal health.

Prevalence and antimicrobial resistance pattern of bacterial strains isolated from patients with urinary tract infection in Messalata Central Hospital, Libya

Objective: To investigate the prevalence of urinary tract infection among patients at Messalata Central Hospital, Libya, to identify the causative bacteria, and to explore their resistance pattern to antimicrobials. Methods: A total number of 1 153 urine samples were collected from patients, who attended daily to Messalata Central Hospital, Libya, in a study extended for one year. Antimicrobial susceptibility testing and isolates typing were done using Phoenix BD(BD diagnostic). Resistance was confirmed manually using agar disk diffusion method. Results: Of the 1 153 urine samples tested, 160(13.9%) samples were positive, from which 17 different, solely Gram negative, uropathogens were identified. Escherichia coli were the most prevalent(55.6%) bacteria, followed by Klebsiella pneumoniae subspecies pneumoniae(16.3%), Proteus mirabilis(6.3%), Pseudomonas aeruginosa(5.6%), Enterobacter cloacae and Klebsiella oxytoca(2.5%, each), Citrobacter koseri and Providencia rettgeri(1.9%, each), Acinetobacter baumannii, Enterobacter aerogenes and Proteus vulgaris(1.3%, each), and Aeromonas caviae, Citrobacter freundii, Cronobacter sakazakii, Enterobacter amnigenus biogroup 2, Pseudomonas putida and Serratia marcescens(0.6%, each). The isolated uropathogens showed increased levels of resistance ranged from 10.5% to 64.5%, with an overall resistance of 28.9%. Amikacin was the most effective antimicrobial followed by Imipenem and Meropenem(0%, 0.6% and 2.5% resistance, respectively); while, Cephalothin and Ampicillin were the least(80.6% and 90.0% resistance, respectively) effective. Conclusions: The obtained results emphasized the emergence of highly resistant bacteria to most of tested antimicrobials and raise the alarm for physicians to change their treatment pattern depending on antimicrobial susceptibility results.

Analysis on Antimicrobial Resistance of Clinical Bacteria Isolated from County Hospitals and a Teaching Hospital

The distinction of antimicrobial resistance of clinical bacteria isolated from county hospitals and a teaching hospital was investigated. Disc diffusion test was used to study the antimicrobial resistance of isolates collected from county hospitals and a teaching hospital. The data was analyzed by WHONET5 and SPSS statistic software. A total of 655 strains and 1682 strains were collected from county hospitals and a teaching hospital, respectively, in the year of 2003. The top ten pathogens were Coagulase negative staphylococci （CNS）, E. coil, Klebsiella spp. , S. areus, P. aeruginosa, Enterococcus spp. , Enterobacter spp. , otherwise Salmonella spp. , Proteus spp. , Shigella spp. in county hospitals and Streptococcus spp. , Acinetobacter spp. , X. maltophilia in the teaching hospital. The prevalence of multi-drug resistant bacteria was 5 % （4/86） of methicillin-resistant S. areus （MRSA）, 12 % （16/133） and 15.8 % （9/57） of extended-spectrum β-lactamases producing strains of E. coil and Klebsiella spp. , respectively, in county hospitals. All of the three rates were lower than that in the teaching hospital and the difference was statistically significant （P〈0. 01）. However, the incidence of methicillin-resistant CNS （MRCNS） reached to 70 % （109/156） in the two classes of hospitals. Generally, the antimicrobial resistant rates in the county hospitals were lower than those in the teaching hospital, except the resistant rates of ciprofloxacin, erythromycin, clindamycin, SMZco which were similar in the two classes of hospitals. There were differences between county hospitals and the teaching hospital in the distribution of clinical isolates and prevalence of antimicrobial resistance. It was the basis of rational use of antimicrobial agents to monitor antimicrobial resistance by each hospital.

Antimicrobial susceptibility testing in veterinary medicine:performance,interpretation of results,best practices and pitfalls

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.

Rapid, automated, and reliable antimicrobial susceptibility test from positive blood culture by CAST‐R

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.

Trend of distribution and antimicrobial resistance in uropathogens in China from the CHINET antimicrobial resistance surveillance program,a 7-year retrospective study

Urinary tract infections(UTIs)are common urological diseases that easily relapse and have led to an increasing eco-nomic and health burdens.The China Antimicrobial Surveillance Network(CHINET)system is one of the most influ-ential antimicrobial resistance surveillance networks in China.This study analyzed antimicrobial resistance and distri-bution trends of uropathogens from 2015 to 2021 using the CHINET system.A total of 261,893 non-duplicate strains were collected;Gram-positive bacteria accounted for 23.8%while Gram-negative bacteria accounted for 76.2%.Escherichia coli,Enterococcus faecium,Klebsiella pneumoniae,and Enterococcus faecalis were the most common species.The resistance to vancomycin,linezolid,and teicoplanin in E.faecalis and E.faecium was less than 3%.The prevalence of carbapenem-resistant strains of E.coli,K.pneumoniae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 1.7%,18.5%,16.4%,and 40.3%,respectively.The prevalence of carbapenem-resistant A.baumannii increased from 27.6%in 2015 to 43.4%in 2021.The prevalence of methicillin-resistant Staphylococcus aureus decreased from 40.6%in 2015 to 22.9%in 2021.The resistance rates to mostβ-lactam antimicrobials,aminoglycosides and fluo-roquinolones in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii isolated from ICU inpatients were significantly higher than in those isolated from outpatients and non-ICU inpatients.This study indicates that E.coli,Enterococcus,and K.pneumoniae were the most commonly isolated uropathogens in China.The bacterial species isolated and their antimicrobial resistance patterns differed in different patient populations.More attention must be paid uropath-ogen resistance surveillance to provide data for the rational use of antimicrobial agents.

Rapid antimicrobial susceptibility testing for mixed bacterial infection in urine by AI-stimulated Raman scattering metabolic imaging

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.

E-test法和Rosco纸片法检测申克孢子丝菌对伊曲康唑和氟康唑的敏感性试验

目的探讨申克孢子丝菌的体外抗真菌药敏试验E-test法和Rosco纸片法的可比性,观察申克孢子丝菌对伊曲康唑和氟康唑的敏感性。方法采用临床实验室标准化协会(CLSI)颁布的M27-P方案中的E-test法检测和Rosco纸片法检测申克孢子丝菌在菌丝相时对伊曲康唑、氟康唑的MIC值。结果采用E-test法和Rosco纸片法检测20株临床分离株25℃菌丝相时,伊曲康唑的MIC值范围分别为:0.012～2.0μg/mL,14～29mm,氟康唑的MIC值范围分别为:>256μg/mL,0mm。结论体外抗真菌药敏试验E-test法和Rosco纸片法有较好的一致性和重复性。申克孢子丝菌25℃菌丝相时对伊曲康唑、氟康唑的敏感性存在差异,对伊曲康唑的敏感性高于氟康唑。

七氟烷对结核分枝杆菌体外抑菌效果的评价

目的:探究临床常用镇静、镇痛和肌肉松弛剂对结核分枝杆菌(Mycobacterium tuberculosis,MTB)的体外抑菌活性。方法:检测5种临床常用镇静剂(包括吸入用的七氟烷和静脉用的丙泊酚)、镇痛剂地佐辛和肌肉松弛剂(罗库溴铵和阿曲库铵)对MTB标准株H37Rv的最低抑菌浓度(minimal inhibit concentration,MIC)。对具有较好体外抑菌活性的七氟烷通过菌落形成单位(CFU)计数方法观察不同浓度处理后MTB的菌落数量变化。制备痰菌悬液模拟痰液环境,观察七氟烷在4 h内的抗结核活性;使用人单核细胞白血病细胞(THP-1)验证4 h内七氟烷的细胞毒性。结果:丙泊酚、地佐辛、罗库溴铵和阿曲库铵对MTB均无明显的体外抑菌活性,仅七氟烷在体外对H37Rv有抑菌效果,MIC值为1.25%。进一步发现,3%、6%、9%浓度七氟烷处理8 h MTB的菌落计数(log10CFU)分别为3.086±0.196、4.165±0.083和4.162±0.100,均明显低于对照组(4.489±0.083),差异有统计学意义(F=7.630,P=0.003);9%七氟烷处理48 h MTB的菌落计数(log10CFU)为3.000±0.000,明显低于对照组的5.077±0.191,差异有统计学意义(F=313.300,P<0.001)。在痰菌悬液中,用9%七氟烷处理2 h和4 h可产生明显的抗MTB活性,MTB菌落计数(log10CFU)分别为5.846±0.384和5.947±0.280,均明显低于对照组[MTB菌落计数(log10CFU)分别为6.264±0.150和6.331±0.162],差异均有统计学意义(F值分别为4.173和6.091,P值分别为0.025和0.006)。并且CCK-8实验发现,0~9%浓度七氟烷处理THP-1细胞4 h内均可维持细胞存活率在(81.033±3.190)%以上。结论:七氟烷具有良好的体外抗MTB活性,在模拟痰液环境中保持短时间杀菌的效果,且安全性良好。

一例鹦鹉肺炎克雷伯菌感染的诊断报告

山东省某养殖场饲养的12日龄鹦鹉出现呼吸困难、鼻腔内充满干酪样分泌物等症状,采集死亡鹦鹉的鼻腔内分泌物和肺脏组织分离细菌,通过生化试验、16S rDNA测序和系统进化树分析,初步证实该病由肺炎克雷伯菌肺炎亚种所致。药物敏感性试验结果显示,该分离菌对大部分药物耐受,仅对氟苯尼考、氧氟沙星等药物高度敏感,对多粘菌素B、阿米卡星等药物中度敏感。本研究为鹦鹉肺炎克雷伯菌感染的临床诊治提供了理论依据和参考。

凝固酶阴性葡萄球菌D-test阳性率及耐药性研究

目的了解院内感染凝固酶阴性葡萄球菌(CNS)D-test阳性率及其耐药性。方法细菌鉴定应用VITEK全自动细菌鉴定分析系统;MIC采用琼脂平板稀释法;D-test采用K-B纸片法,按CLSI规定的标准进行。结果从临床各种感染标本中分离得到50株CNS,其中耐药表型iMLSB(D-test阳性)占44.0%,耐药表型cMLSB占40.0%,耐药表型MSB占14.0%。万古霉素(VAN)、左氧氟沙星(LVF)、阿米卡星(AMK)和头孢唑啉(CFZ)对D-test阳性CNS的抑菌率分别为100%,59.1%,95.5%和90.9%;VAN,LVF,AMK和CFZ的MIC90分别为2.0,8.0,4.0和16.0mg/L;而VAN+LVF,VAN+AMK,VAN+CFZ,LVF+AMK和LVF+CFZ联合后MIC90分别为2.0,1.0,1.0,2.0和4.0mg/L。VAN+LVF,VAN+AMK,VAN+CFZ,LVF+AMK和LVF+CFZ联合的FIC指数<1的协同作用分别为36.4%,31.8%,77.3%,36.4%和36.4%。结论CNS的耐药性越来越高,其耐药机制复杂多样,临床应根据病原菌不同耐药表型和药敏实验结果正确合理的选用抗菌药物。对D-test阳性的CNS引起的重症感染最好用VAN+CFZ或LVF联合用药。

Etest测定295株临床分离菌对抗菌药物的耐药性

目的 监测 2 95株临床分离菌对常用抗菌药物的耐药性 ,为临床合理选用抗菌药物提供实验研究依据。方法 通过E试验方法测定四川大学华西医院、第二医院 6个月内部分临床分离菌 12种 2 95株对临床常用 β 内酰胺类、氟喹诺酮类及大环内酯类的耐药性。结果 32 .8%的金葡球菌耐苯唑西林 ,且为多重耐药株 ;37%～ 41%化脓性链球菌耐大环内酯类 ;肠球菌属 10 0 %耐头孢菌素 ;肺炎链球菌 8%耐酶抑制剂复合制剂 ;流感嗜血杆菌 85 %～ 94%耐克拉霉素、罗红霉素 ,仅 5 %耐阿奇霉素 ;肺炎克雷伯氏菌与大肠埃希氏菌产超广谱 β 内酰胺酶分别为 45 %与 35 % ;变形杆菌属对 β 内酰胺类耐药率为 30 %～ 5 0 % ,对氟喹诺酮类敏感 ;肠杆菌属细菌 2 5 %耐氟喹诺酮类、5 0 %耐 β 内酰胺类 ,但对头孢哌酮 /舒巴坦敏感 ;不动杆菌属细菌对氟喹诺酮类耐药率为 40 % ,对第二、三代头孢菌素类为 6 0 %～ 75 %、对 β 内酰胺酶抑制剂复合制剂的耐药率在35 %～ 5 5 % ;铜绿假单胞菌 10 0 %耐所试广谱青霉素、头孢呋辛 ,75 %耐头孢曲松、2 5 %耐头孢哌酮 /舒巴坦 ,5 %耐氟喹诺酮类 ;4株粘膜炎莫拉氏菌完全耐大环内酯类 ,耐环丙沙星与头孢克洛各 1株。结论 临床分离致病菌对常用抗菌药物均有不同程度的耐药性 。

Intraprocedural gastric juice analysis as compared to rapid urease test for real-time detection of Helicobacter pylori

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.

Current status and trends of antimicrobial resistance among clinical isolates in China:a retrospective study of CHINET from 2018 to 2022

Antimicrobial resistance(AMR)is a pressing issue in China,with antibiotic therapy becoming less effective against bacterial infections.To address this challenge,the China Antimicrobial Surveillance Network(CHINET)was established in 2005 to monitor antimicrobial resistance in the country.This study analyzed the CHINET data from teaching hospi-tals and evaluated the trends of AMR in China from 2018 to 2022.A range of 163,636 to 301,917 isolates was obtained per year,with the majority being Gram-negative bacilli(69.0%to 71.8%).The proportion of important multidrug-resistant pathogens remained stable over the years.While the analysis showed diverse AMR profiles for different bac-terial species.Over the five years,generally decreased resistance rates were observed from the majority of the tested species.For example,resistance to ceftriaxone decreased in Escherichia coli and Klebsiella pneumoniae,while resistance to imipenem and meropenem decreased in Pseudomonas aeruginosa.Moreover,resistance to methicillin,gentamicin,fosfomycin,and clindamycin also decreased in clinical Staphylococcus aureus isolates.On the other hand,resistance levels of Acinetobacter baumannii remained stable.Our study provides a comprehensive overview of the AMR profiles of common bacterial species in China and highlights the ongoing efforts to address this challenge.