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.

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.

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.

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.

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.

AST-YS08药敏卡片检测酵母菌体外抗真菌药物敏感性的评价

目的评估使用AST-YS08真菌药敏卡片进行酵母菌体外抗真菌药物敏感性试验的准确性。方法选取该院2019年3月29日至2022年5月8日临床分离的念珠菌和新型隐球菌,共100株,分别使用该卡片及微量肉汤稀释法(BMD法)检测菌株对5-氟胞嘧啶、伏立康唑、米卡芬净、两性霉素B、氟康唑、卡泊芬净的最小抑菌浓度(MIC),比较该卡片与BMD法的检测时长、基本一致率(EA)和分类一致率(CA)。结果对于念珠菌,AST-YS08卡片检测时长为(13.63±2.55)h,与BMD法检测的总EA为87.2%,6种药物中EA最低的为卡泊芬净(55.8%);AST-YS08卡片与BMD法检测白色念珠菌及近平滑念珠菌复合群的各类药物CA均>90.0%,CA较低的念珠菌及对应药物为光滑念珠菌伏立康唑(78.9%)及卡泊芬净(5.3%)、克柔念珠菌卡泊芬净(0.0%)、热带念珠菌氟康唑(81.3%)及伏立康唑(56.3%)。对于培养48 h的新型隐球菌,AST-YS08卡片检测时长为(20.67±5.13)h,与BMD法检测的总EA为100.0%,各类药物两种方法的CA均>90.0%;AST-YS08卡片检测培养24 h菌株时检测时长为(20.31±5.84)h,AST-YS08卡片检测与BMD法检测的总EA为96.3%,除两性霉素B(78.6%)外,其余药物两种方法的CA均>90.0%。结论检测念珠菌和新型隐球菌药物敏感性时,AST-YS08药敏卡片与BMD法一致率较高,是一种准确、快速的商品化酵母菌药敏试剂,但念珠菌对卡泊芬净非敏感的结果需谨慎报告,似平滑念珠菌对伏立康唑的药物敏感性需使用其他方法检测。

普雷沃菌血流感染:一项为期10年的单中心回顾性研究

目的 提高临床医生对普雷沃菌血流感染的认识,减少误诊和漏诊率,拓宽诊疗思路。方法 收集2013年5月—2023年5月南京大学医学院附属某医院普雷沃菌血流感染患者的临床资料,回顾性分析普雷沃菌血流感染患者的危险因素、感染来源、感染菌种、临床表现、实验室检查结果、治疗及转归。结果 共纳入23例确诊为普雷沃菌血流感染的患者,共中男性15例(65.2%),女性8例(34.8%)。大部分患者血流感染前有相关诱发因素,如手术操作(11例,47.8%)、恶性肿瘤(10例,43.5%)、糖尿病(9例,39.1%)、导尿管置入(10例,43.5%)等。感染菌种共9类,主要为颊普雷沃菌(6例,26.1%)、二路普雷沃菌(5例,21.7%)和中间普雷沃菌(4例,17.4%)。感染来源主要为肝胆系统(6例,26.1%)、腹腔及胸腔(4例,17.4%)和泌尿生殖道(4例,17.4%)。所有患者均有畏寒、发热表现,血液炎症指标明显升高,4例(17.4%)并发感染性休克,18例(78.3%)患者经恰当的抗感染治疗后预后良好。结论 当怀疑不典型病原菌普雷沃菌血流感染时,应尽早去除诱发因素,积极留取血液送培养,依据药敏试验合理应用抗菌药物,有利于迅速控制感染,改善预后。

一株猪源化脓隐秘杆菌的分离鉴定及其耐药性分析

为确定黑龙江省某养殖场因呼吸道症状急性死亡病猪的致病菌,并探究其主要生物学特性,本研究采集病死猪内脏组织,通过细菌分离、革兰氏染色、生化鉴定、16S r RNA基因的PCR扩增、测序、系统进化树的构建对分离菌进行种属鉴定;通过微量肉汤稀释法分析该菌对8类10种抗生素的敏感性;通过Illumina PE150对细菌全基因组测序,采用ResFinder软件分析分离菌的耐药基因,并分析耐药基因与耐药表型的相关性。利用VFanalyzer软件、BLASTN比对分离菌的毒力基因。结果显示,该菌株在10%脱纤维羊血平板培养基上培养24 h后形成表面光滑具有β-溶血环的单菌落;革兰氏染色结果显示呈蓝紫色短棒状杆菌;生化鉴定结果显示该分离菌的生化特性与化脓隐秘杆菌符合。16S r RNA基因的PCR结果显示,扩增到1397 bp的目的基因序列,与GenBank中序列比对结果显示该菌株与已报道的化脓隐秘杆菌同源性高达99%。16S r RNA基因系统进化树分析结果显示分离菌与辽宁沈阳的牛源化脓隐秘杆株TZQ 01株处于同一分支,与日本的猪源分离株NIAH13531处于较近分支,以上结果可确定该分离菌为化脓隐秘杆菌,并将其命名为FY-4-Z-1。药敏试验结果显示,该菌株对头孢菌素类的头孢噻呋,青霉素类的青霉素、阿莫西林,大环内酯类的红霉素,截短侧耳素类的泰妙菌素等抗生素敏感,对四环素类的四环素,氨基糖苷类的链霉素耐药。利用组装软件SPAdes对获得的全基因组测序数据组装后获得了分离菌全基因组草图,结果显示分离菌基因组大小为2399.961 kb;耐药基因分析结果显示,该菌株基因组包含3种耐药基因,分别是氨基糖苷类的ant(6)-la、大环内脂类的erm(X)、四环素类的tet(W)耐药基因,其中在化脓隐秘杆菌中首次检测到ant(6)-la基因。该菌株对四环素和链霉素的药敏试验结果与其耐药基因检测结果相符,而红霉素敏感表型可能与其耐药基因erm(X)的移码突变有关。利用BLASTN和VFanalyzer软件进行毒力基因检测,结果显示共检测到8个已知毒力基因和24个候选毒力相关基因。本实验进一步丰富了猪源化脓隐秘杆菌的相关研究,为规模化猪场化脓隐秘杆菌病的防治提供了重要的参考依据和用药指导。

Vitek 2 Compact AST-N334、AST-N335、AST-P639中国定制药敏卡性能评估

目的评估Vitek 2 Compact AST-N334、AST-N335和AST-P639中国定制药敏卡的性能。方法随机收集权威机构质控菌株73株和2018年1—6月华山医院住院患者首次临床分离株112株。以权威机构提供的质控菌株为检测对象,采用3种中国定制药敏卡及微量肉汤稀释法(BMM)进行平行试验,以室间质量评价结果为参考标准,评估中国定制药敏卡及BMM的可靠性。以临床分离株为检测对象,以BMM结果为参考标准,评估中国定制药敏卡对临床分离株耐药多样性检测的准确性。结果以质控菌株为检测对象,以权威机构提供的抗菌药物敏感性试验结果为标准,AST-N334、AST-N335、AST-P639的分类一致率(CA)分别为95.5%(126/132)、96.8%(179/185)、99.5%(182/183)。以临床分离株为检测对象,以BMM药物敏感性试验结果为参考标准,AST-N334标准一致率(EA)为88.4%(961/1087)、CA为94.6%(903/955)、非常重大错误(VME)占0.3%(3/955)、重大错误(ME)占1.9%(18/955)、微小错误(MIE)占3.2%(31/955);AST-N335 EA为89.9%(1388/1544)、CA为95.1%(1414/1487)、VME占0.3%(5/1487)、ME占0.8%(12/1487)、MIE占3.8%(56/1487);AST-P639 EA为95.4%(541/567)、CA为98.7%(389/394)、ME占0.5%(2/394)、MIE占0.8%(3/394)。结论Vitek 2 Compact AST-N334、AST-N335、AST-P639中国定制药敏卡准确性高,具有临床应用可信度,但也存在一定的错误率及局限性,实验室检测人员应予以关注。

拉曼光谱用于细菌快速药敏检测的研究进展

致病菌对人类健康构成重大威胁,抗菌药物的滥用导致了细菌耐药性的发展和传播。目前,临床微生物室常用的药敏试验,如纸片扩散法、浓度梯度纸条扩散法、肉汤稀释法和全自动药敏分析等都是基于细菌生长的方法,且操作流程繁琐,需要8~16 h才能出结果。该文从快速药敏检测(RAST)的研究出发,重点叙述了拉曼光谱在RAST领域的研究进展。利用拉曼光谱对细菌进行基于代谢表型的药敏检测,检测时间明显缩短,优于常规基于细菌生长的药敏方法。但该方法缺少大规模的临床分离株验证,而且难以实现临床标本中细菌的免分离检测。该文对RAST技术的临床验证、可重复性评估、临床适用性评估、准确性评估、拉曼光谱与电阻抗及微流控技术的创新结合及其在复杂临床标本中直接药敏检测等方面进行展望。

耐碳青霉烯类鲍曼不动杆菌联合药敏试验研究

目的了解耐碳青霉烯类鲍曼不动杆菌(CRAB)的分布特征和耐药状况,评价以黏菌素(COL)为基础,分别与头孢哌酮/舒巴坦(SCF)、替加环素(TGC)、亚胺培南(IPM)、美罗培南(MEM)、阿米卡星(AK)和左氧氟沙星(LEV)联合的体外抗菌效果,为临床抗感染治疗提供参考。方法收集2022年我院75株非重复分离的CRAB菌株,用WHONET 5.6软件分析其临床分布和耐药情况。从中筛选25株,采用微量肉汤稀释法测定各药物单独及联合时的最低抑菌浓度(MIC),用棋盘法抑菌试验计算部分抑菌浓度指数(FIC)判定联合效应。结果2022年我院共分离鲍曼不动杆菌145株,其中CRAB 75株,检出率51.7%。CRAB在>70岁老年患者中检出率最高(40.0%),主要来源于血液(41.3%)和痰液(37.3%)标本,ICU是主要分离科室。75株CRAB对5种抗菌药物哌拉西林(PRL)、哌拉西林/他唑巴坦(TZP)、头孢曲松(CRO)、IPM和MEM均100%耐药;对3种药物氨苄西林/舒巴坦(SAM)、头孢吡肟(FEP)和复方磺胺甲噁唑(SXT)的耐药率均>95%;对LEV、SCF、AK、TGC和COL的耐药率分别为86.7%、82.7%、77.4%、2.4%和0.0%。25株CRAB的联合药敏试验显示,COL分别与SCF和TGC的协同率最高(92%和80%),协同率与相加率之和均为100%;COL与IPM、MEM、AK、LEV联合的协同率依次为64%、72%、56%和48%,均无拮抗作用。结论CRAB呈高度耐药,老年和ICU患者是高危人群。COL与SCF联合具有最佳协同作用,COL与LEV联合效果最差,值得临床参考。

用CLSI和EUCAST两种标准判定产ESBLs菌株药敏结果的差异

目的分析美国CLSI标准和欧洲EUCAST标准判读产超广谱β-内酰胺酶(ESBLs)的大肠埃希菌(E.coli)和肺炎克雷伯菌(K.pneumoniae)对4种常用广谱头孢菌素药敏结果的差异。方法收集按CLSI标准因产ESBLs而将广谱头孢菌素药敏结果由敏感或中介改为耐药的E coli和K.pneumoniae,用琼脂稀释法检测最低抑菌浓度(MIC),用CLSI标准和EUCAST标准进行敏感性界定。同时用PCR及Hodge-test检测4种ESBLs基因和高活性β-内酰胺酶。结果55株菌中53株扩增出介导ESBLs的相关基因,Hodge-test显示55株菌均产高活性β-内酰胺酶;用EUCAST标准界定,55株菌株对头孢三嗪和头孢噻肟均耐药,对头孢他啶和头孢吡肟敏感的菌株分别有5和7株。结论在目前的耐药现状中,用CLSI规则和用EUCAST折点判读E.coli和K.pneumoniae对4种常用第三代和第四代头孢菌素敏感性,对临床治疗结果进行预测的差异主要出现在产ESBLs且头孢他啶和头孢吡肟MICs值≤1μg/m1的菌株中。

2018年~2021年河北省部分地区鸡源沙门菌的生物学特性及致病性研究

为调查河北地区鸡源沙门菌及其血清型的流行及分布情况,并分析其的致病性,本研究于2018年~2021年在河北省7个地区34个养鸡场共收集631份发病鸡肛拭子和62份病料样品共计693份,分别接种普通琼脂培养基分离细菌并纯化后经革兰氏染色镜检;将分离菌分别接种不同的培养基培养,并对分离菌经生化及16S r RNA基因的PCR及测序鉴定,随机选择32条测序序列经NCBI的BLAST比对,并采用DNAStar软件分析该基因的同源性。采用玻片凝集法鉴定分离菌的血清群及血清型并统计各血清群与血清型在河北不同地区的分布。结果显示,从693份病料样品中共分离到238株沙门菌,除3株未定群外,其余分离菌分属于A、B、C、D、E、F 6个血清群,其中D群最多达69.7%(166/238);238株沙门菌分属于7个不同的血清型和未定型,依次为鸡白痢沙门菌(91/38.2%)、甲型副伤寒沙门菌(43/18.0%)、鸡伤寒沙门菌(40/16.8%)、肠炎沙门菌(39/16.4%)等。血清群与血清型分布的统计结果显示,除张家口地区流行A群血清群外,其余地区流行的血清群均为D群;张家口地区流行鸡白痢沙门菌;秦皇岛地区有14种血清型,其中甲型副伤寒沙门菌为其流行血清型;石家庄、承德、唐山流行的均为鸡白痢沙门菌,邢台及保定地区分别流行肠炎沙门菌与鸡伤寒沙门菌。通过K-B药敏纸片法检测238株分离菌对7类共22种药物的敏感性;采用PCR检测分离菌的相关耐药基因并采用SPSS26.0软件中的Fisher确切概率法分析分离菌耐药表型与耐药基因之间的相关性。选取12株不同血清型的分离菌以0.2 m L/只(3×108cfu/mL)感染雏鸡,分析各分离菌对雏鸡的致病性。药敏试验结果显示,对苯唑西林、红霉素、青霉素、甲氧苄啶、氨苄西林、四环素耐药的菌株分别占97.5(232/238)、89.1%(212/238)、78.6%(187/238)、74.8%(178/238)、74.4%(177/238)、64.3%(153/238),对其它药物耐药的菌株均在32%以下,但均对头孢类药物敏感;且分离菌多呈多重耐药性(58.4%,139/238),耐6重药物的菌株(32.8%,78/238)与耐5重药物的菌株(11.8%,28/238)最多。耐药基因检测结果显示,对β-内酰胺类、磺胺类、大环内酯类、四环素类、氨基糖苷类药物的耐药基因tem、erm(B)a、tetA、strA-B的检出率分别为100%(238/238)、75.2%(178/238)、71%(169/238)、65.6%(156/238)及31.9%(76/238)。未检测到喹诺酮类和醛胺醇类耐药基因。经分析,氨基糖苷类、四环素类、磺胺类、β-内酰胺类、大环内酯类药物的耐药表型与其耐药基因的符合率分别为94.7%、98.1%、99.4%、97.5%、79.9%,相关性均较强。致病性试验结果显示,12株分离菌均能致感染鸡出现不同的临床症状及肝脏和肠道的剖检病变,且能对鸡造成不同程度的死亡,其中以致鸡死亡10只(100%)、7只(87%)为主,并从死亡鸡的肝脏再次分离到相应细菌。上述结果表明,本研究从河北不同地区分离的238株沙门菌血清群与血清型众多,大多数沙门菌的耐药性较强且多呈多重耐药性,其携带的5类药物的耐药基因与其相对应的耐药表型均呈较强的相关性,且分离菌对雏鸡呈不同的致病性。本研究为河北地区鸡源沙门菌的流行病学调查及其感染的防治提供参考依据。

牛肠道大肠杆菌的分离鉴定及耐药性分析

【目的】新疆昌吉市周边某牛场大量犊牛严重腹泻,排黄色水样稀便,有的带血,并出现精神萎靡、食欲不振等症状,为确定此次发病的病原并提供治疗参考。【方法】通过对该牛场出现的犊牛腹泻粪样进行细菌鉴定及分型并进行耐药性分析。【结果】PCR鉴定结果显示为大肠杆菌阳性,染色镜检结果符合大肠杆菌形态特征,分离菌株具有K99黏附性基因。药敏试验结果显示该分离菌株仅对多黏菌素B中介(既不敏感也不耐药),对其他所有受试抗菌药物耐药。在致病性试验中,小鼠在15 h内陆续死亡,说明该菌株具有一定致病力。【结论】结果表明,该牛场犊牛腹泻粪便中分离的菌株为产肠毒素性大肠杆菌,携带K99毒力基因,对多黏菌素B中介,具有一定致病力。

EUCAST和CLSI微量稀释法检测曲霉体外药物敏感试验差异比较

目的比较欧洲抗菌药物敏感试验委员会（European Committeeon Antimicrobial Susceptibility Testing，EUCAST）和美国临床实验室标准化协会（Clinicaland Laboratory Standards Institute，CLSI）微量稀释法检测曲霉体外药物敏感性的差异。方法分别用EUCAST方法和CLSI方法检测116株曲霉对两性霉素B、伏立康唑、伊曲康唑、卡？白芬净和米卡芬净的敏感性，比较两种方法的基本符合率、药敏符合率、极重大误差率和重大误差率。结果EUCAST方法和CLSI方法对116株曲霉药敏检测的基本符合率为96．3％～100％。两方法检测烟曲霉对伏立康唑的药敏符合率98．8％，重大误差为1．2％，极重大误差率为0。烟曲霉和黑曲霉对两性霉素B以及烟曲霉和黄曲霉对伊曲康唑的药敏符合率均为100％，重大误差率和极重大误差率均为0。结论EUCAST方法和CLSI方法对检测曲霉体外药物敏感性具有良好的一致性。

一例比格犬肺炎克雷伯氏菌病的诊断及防控

为了诊断青岛博隆实验动物养殖基地比格犬病死原因并制定有效防控措施,试验通过临床观察和病理解剖对病犬进行初步诊断;无菌采集病死幼犬肺组织,采用特异性聚合酶链式反应(polymerase chain reaction,PCR)诊断三种常见犬呼吸道病毒,通过细菌形态学观察、生化试验、基因测序鉴定分离病原菌,并通过小鼠致病性试验和药敏试验分析其致病性和优化用药方案。结果表明:犬发病时主要表现为咳嗽、流鼻涕、食欲不振和轻度腹泻等症状。剖检可见胸腔积液,肺叶淤血和坏死。PCR鉴定犬腺病毒2型(canineadenovirus type 2,CAV 2)、H3N2亚型犬流感病毒(H3N2 subtype canine influenza virus,CIV)和犬副流感病毒(canine parainfluenza virus,CPIV)均为阴性。细菌分离培养显示为该菌革兰氏阴性的粗短杆菌;生化试验和16S rDNA测序鉴定该菌为肺炎克雷伯菌。回归试验结果表明该菌可引起小鼠肺炎症状,具有较强致病力。药敏试验结果显示分离菌株对阿奇霉素、环丙沙星、恩诺沙星敏感,对氨苄西林、头孢他啶、庆大霉素、头孢噻肟、头孢替安、头孢曲松耐药。经犬舍消毒和药物治疗后,该犬养殖场的病情得到有效控制。

山羊源海藻糖比伯斯坦杆菌分离鉴定与药敏试验

试验旨在对陕西省某奶山羊场死于肺炎的羔羊进行病原诊断,无菌采集病死羔羊肺脏,对细菌进行分离培养、染色镜检、生化鉴定和PCR鉴定,并对分离株进行小鼠致病性试验和药敏试验。结果显示,从病死羔羊的肺脏组织中成功分离到一株海藻糖比伯斯坦杆菌,该分离株对小鼠具有致病性,对头孢噻呋钠、四环素和恩诺沙星等药物敏感,对阿莫西林、氨苄西林和链霉素等药物耐药。研究表明,海藻糖比伯斯坦杆菌为导致羔羊肺炎的病原菌,与羔羊死亡密切相关,临床建议选择头孢噻呋钠等敏感药物进行治疗以有效控制病情。

2型糖尿病患者泌尿系统感染病原菌的构成特点及耐药性分析

目的探讨2型糖尿病患者泌尿系统感染病原菌的构成特点及耐药情况,为临床用药治疗提供参考依据。方法对2020年1月—2023年8月南明区人民医院收治的107例2型糖尿病合并泌尿系统感染患者资料进行回顾性分析,统计泌尿系统感染病原菌的构成以及耐药情况,并比较不同性别之间病原菌和耐药性的差异。结果107例患者清洁中段尿标本共检出109株病原菌,其中革兰氏阴性菌占80.7%(88株),革兰氏阳性菌和念珠菌分别占14.7%(16株)及4.6%(5株),大肠埃希菌是最常见的致病菌,不同性别感染病原菌的构成情况具有差异,女性患者大肠埃希菌的检出率高于男性。药敏结果显示,大肠埃希菌对多种抗菌药物的耐药率超过60.0%,对亚胺培南100%敏感;粪肠球菌对万古霉素和利奈唑胺100%敏感;大肠埃希菌对氨苄西林和环丙沙星的耐药率明显高于粪肠球菌(P<0.05),对呋喃妥因的耐药率却低于粪肠球菌(P<0.05)。不同性别检出的大肠埃希菌对常用抗菌药物的耐药率差异无统计学意义(P>0.05)。结论2型糖尿病患者泌尿系统感染病原菌主要是革兰氏阴性菌,其中大肠埃希菌是最常见的致病菌。不同性别的患者感染病原菌的构成有所不同,不同病原菌之间对抗菌药物的耐药率具有差异,而不同性别患者检出的主要病原菌对常用抗菌药物的耐药率无明显差异,临床应根据病原菌培养及药敏结果,合理选择抗菌药物治疗。

MALDI-TOF MS与VITEK2在血流感染致病菌快速鉴定及药敏试验中的应用

目的:探究基质辅助激光解吸/电离飞行时间质谱(Matrix-assisted laser desorption/ionizationtime-of-flight mass spectrometry,MALDI-TOF MS)与VITEK2在血流感染致病菌药敏试验中的联合应用效果。方法:选取景德镇市第二人民医院检验科2022年1月1日至2022年12月31日血流感染阳性样本126份,分别行常规鉴定及MALDI-TOF MS鉴定,完成菌株鉴定后通过VITEK2系统行抗菌药物敏感性试验(Antimicrobial susceptibility testing,AST),比较2种鉴定方法的细菌菌株鉴定结果及细菌耐药情况。结果:常规鉴定方法对革兰氏阴性、革兰氏阳性菌在属、种水平鉴定符合率达到100%;MALDI-TOF MS鉴定革兰氏阴性菌在属水平的符合率达97.7%(85/87),在种水平的符合率达95.4%(83/87),2例无结果(1例阴沟肠杆菌阴沟亚种,1例少动鞘氨醇单胞菌);MALDI-TOF MS鉴定革兰氏阳性菌在属、种水平的符合率均达97.4%(38/39),1例无结果(科氏葡萄球菌解脲亚种)。常规鉴定+VITEK2对革兰氏阴性菌AST分析的分类一致(Categorical agreement,CA)、基本一致(Essential agreement,EA)分别达到98.6%(1086/1101)、99.5%(1096/1101),对革兰氏阳性菌AST分析的CA、EA分别达到98.6%(550/558)、99.6%(556/558);MALDI-TOF MS+VITEK2(VITEK MS)对革兰氏阴性菌AST分析的CA、EA分别达到98.3%(1082/1101)、99.5%(1095/1101),对革兰氏阳性菌AST分析的CA、EA分别达到97.8%(546/558)、99.5%(555/558)。进一步参考肉汤稀释法药敏结果行一致性分析。结果发现,常规鉴定+VITEK2在革兰氏阴性菌的药敏试验中,10份AST鉴定结果出现小误差(Minus errors,MIE),5份AST鉴定结果出现重大误差(Major errors,ME);在革兰氏阳性菌的药敏试验中,8份AST鉴定结果出现MIE,2份AST鉴定结果出现ME。VITEK MS在革兰氏阳性菌的药敏试验中,13份AST鉴定结果出现MIE,6份AST鉴定结果出现ME;在革兰氏阳性菌的药敏试验中,9份AST鉴定结果出现MIE,3份AST鉴定结果出现ME。结论:MALDI-TOF MS联合VITEK2在临床血流感染致病菌鉴定及药敏试验中可快速、精确实现诊断并提供AST报告。

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.