108株幽门螺杆菌（Hp）菌株的耐药分析及其对Hp根除的影响

目的：了解北京地区幽门螺杆菌（Hp）的临床耐药情况以及耐药菌株对Hp根除治疗的影响。方法：对108例Hp阳性患者的临床分离株,采用E-test方法测定幽门螺杆菌对甲硝唑、克拉霉素和阿莫西林的敏感性;并用7d三联疗法或3d四联疗法分别对其中41位十二指肠溃疡患者予幽门螺杆菌根除治疗。结果：108株幽门螺杆菌菌株中,对甲硝唑耐药率为37.0%,对克拉霉素耐药率为13.0%,对其中18株幽门螺杆菌菌株进行了阿莫西林的药物敏感试验,发现1例耐药,7d疗法和3d疗法对幽门螺杆菌敏感株的根除率分别为91.7%及80.0%,耐药株的根除率分别为40.0%及25.0%。结论：幽门螺杆菌对甲硝唑、克拉霉素和阿莫西林均有耐药出现,其中以甲硝唑耐药率最高,克拉霉素的耐药率也呈增高趋势,耐药菌株的出现是导致幽门螺杆菌根除治疗失败的主要原因之一。     

cagA基因与幽门螺杆菌对甲硝唑耐药的关系

硝基咪唑类药物甲硝唑(MTZ)有较强的抗幽门螺杆菌(Hp)活性,是三联方案中最广泛应用的抗菌素之一.但Hp对甲硝唑的耐药率较高,限制了其广泛应用[1].已知含cagA基因的Hp菌株是高毒株[2],Hp耐甲硝唑菌株与敏感菌的基因型是否相同?该研究通过对耐药菌和敏感菌cagA基因型的分析以更好地指导幽门螺杆菌的根除.     

头孢类抗生素对根除失败者幽门螺杆菌药敏情况的研究

目的研究初次根除幽门螺杆菌失败者所感染的菌株对头孢呋辛、头孢克肟和头孢丙烯3种头孢类抗生素的敏感情况,探讨这3种头孢类抗生素用于再次根除治疗的可能性。方法收集了62例初次根除失败者胃窦黏膜标本,从其中46例标本中分离培养出了幽门螺杆菌。采用琼脂稀释法检测了这些菌株对3种头孢类抗生素的敏感情况。结果 46例Hp菌株中对头孢呋辛、头孢克肟和头孢丙烯耐药的耐药率分别为4.3%、10.1%和19.6%。结论头孢呋辛、头孢克肟在体外对初次根除幽门螺杆菌失败者所感染的菌株有良好的抗菌作用,可进一步扩大样本进行研究,有望用于初次根除幽门螺杆菌失败者的再次治疗。     

壳聚糖抗幽门螺杆菌的实验研究

目的研究壳聚糖在不同浓度和不同pH条件下对幽门螺杆菌 (Hp)的抑菌作用 ,为壳聚糖的临床应用提供实验依据。方法采用打孔法检测不同浓度和不同pH值壳聚糖对Hp标准菌株SS1和两株患者体内分离出的Hp菌株的抑菌作用。结果壳聚糖对 3种Hp菌株均有抑菌作用 ,且在 3株不同Hp菌株间无差异 (P >0 .0 5 ) ;在pH8.5～ 5 .5范围内 ,随着pH值降低 ,壳聚糖的抗Hp作用增强 (P <0 .0 1 ) ;不同浓度的壳聚糖对Hp的抑菌作用有非常显著差异 (P <0 .0 1 ) ,在 4 %时达高峰。结论壳聚糖在体外对Hp有抑菌作用 ,并且此作用在酸性条件下明显加强 ,这尤为适应胃内的酸性环境     

药敏实验指导及个体化治疗幽门螺杆菌感染的临床探讨

<正>近年来,我国幽门螺杆菌(Hp)的耐药率不断攀升,抗生素耐药菌株的出现已直接影响到Hp根除率,据报道国际标准三联疗法根治率已降至67.2%[1],因此对所分离培养的幽门螺杆菌菌株进行药物敏感试验指导临床治疗意义重大,特别是既往有Hp根除失败的患者,个体化选择性抗生素进行药敏实验,并据结果确定治疗方案,为控制抗菌药物的滥用,降低病原菌耐药水平提供了一条新途径。本文对我院2年来据药敏试验指导根除及传统三联治疗分析,旨在探讨药敏试验对根     

上消化道疾病患者幽门螺杆菌耐药率的实验室研究

目的：探讨上消化道疾病患者幽门螺杆菌耐药率的检测方法和规律。方法：通过改良幽门螺杆菌分离培养和药物敏感试验研究幽门螺杆菌耐药率的变化规律。结果：胃癌幽门螺杆菌检出率阳性为66.67%,其他胃部疾病的Hp感染阳性率为33.45%～49.96%;Hp对左氧氟沙星的敏感率最高,达到98.35%,对阿莫西林等4种药物的敏感率均在75%以上,而对甲硝唑的耐药率达到96.11%。结论：本实验方法对判断幽门螺杆菌耐药率有较大的敏感率。     

幽门螺杆菌rdxA和cagA基因突变与甲硝唑耐药的相关性研究

目的:研究幽门螺杆菌(Hp)编码基因(rdxA)和细胞毒素相关基因A(cagA)突变与Hp对甲硝唑耐药的关系。方法:从贵阳某医院60例消化内科患者胃黏膜标本中分离出Hp临床分离株11株,体外微需氧条件下培养,用E试验(E-test)检测各株Hp临床分离株对甲硝唑的最低抑菌浓度(MIC),聚合酶链式反应(PCR)方法扩增Hp的rdxA和cagA基因并测序,再将耐药株与标准株Hp26695PCR产物进行碱基序列分析。结果:11株Hp临床分离株的MIC均≥256μg·mL-1,rdxA和cagA基因的扩增率均为100%。与标准株Hp26695相应基因序列对比,11株临床分离株的rdxA基因同源性为95%～98%,cagA基因同源性低于94%,rdxA、cagA基因分别有4、10个规律性突变点。结论:贵阳地区Hp对甲硝唑的耐药性可能与rdxA和cagA基因突变有关,其中高耐药性可能与cagA基因有关。     

幽门螺杆菌对左氧氟沙星耐药性分析

摘要目的探讨幽门螺杆菌（Hp）对左氧氟沙星的耐药特征。方法将胃镜活检黏膜标本接种于Hp选择性培养基，37 ℃微需氧环境培养5～7 d，分离Hp菌株。左氧氟沙星药敏试验采用E test法，筛选出耐药菌株和敏感菌株。结果235例标本Hp培养阳性76例，培养阳性率32.34%；136例胃炎患者中，Hp培养阳性28例，阳性率为20.59%；87例消化性溃疡患者中，Hp培养阳性45例，阳性率为51.72%；12例胃癌患者中，Hp培养阳性3例，阳性率为25.00%；消化性溃疡组Hp培养阳性率明显高于胃炎组（P＜0.01）。76例Hp菌株左氧氟沙星耐药13株，占17.11%；敏感株63株，占82.89%。结论该地区Hp对左氧氟沙星耐药率较高，应进一步监测Hp左氧氟沙星耐药情况。     

儿童胃黏膜组织中幽门螺杆菌菌株分型及耐药性分析

目的 探讨儿童胃黏膜中幽门螺杆菌菌株分型与病变程度及抗生素耐药的相关性。方法 通过RT-PCR检测Hp阳性样本的CagA、A2142G、A2143G、rdxA基因,分析菌株分型与胃黏膜病变程度及抗生素耐药的相关性。结果 检测出Hp阳性样本165例,Ⅰ型菌株117例,Ⅱ型菌株48例;克拉霉素耐药65例(39.4%),甲硝唑耐药47例(28.5%),双重耐药的有34例(20.6%),抗生素耐药的共78例(47.3%),抗生素敏感的有87例(52.7%)。Hp菌株分型与胃黏膜病变特征相关性具有统计学意义(P<0.001);克拉霉素、甲硝唑耐药、克拉霉素和或甲硝唑双重耐药与Hp分型均无相关性(均P>0.05)。结论 Ⅰ型Hp感染更易致胃黏膜病变;Hp菌株基因分型与抗生素耐药不相关。     

4种中药对30株广泛耐药铜绿假单胞菌的抑菌作用

目的:探讨黄芩等4种中药对广泛耐药铜绿假单胞菌的抑菌作用。方法:采用中药抗菌试验试管法测定药物的最低抑菌浓度(MIC)。结果:黄芩、连翘、黄连、金银花对30株广泛耐药铜绿假单胞菌有不同程度的体外抑菌作用,MIC均值分别为475.00,345.83,60.94,379.17 mg/m L,与标准菌株ATCC27853的MIC相近。其中黄连的抑菌作用最强。结论:4种中草药对30株广泛耐药铜绿假单胞菌均有不同程度的抑菌作用,本地与外地收集的菌株,抑菌作用无显著性差异(P>0.05)。     

罗红霉素胶囊的抗菌作用

采用试管双倍稀释法，选用部分临床分离致病菌和标准菌株，对罗红霉素胶囊进行了体内外抗菌作用实验．体外抗菌实验结果表明：本品对金黄色葡萄球菌、表皮葡萄球菌、链球菌、流感杆菌等的ＭＩＣ５０分别为：０．１９５，０．６２５，０．７８，０．３９ｍｇ／Ｌ；考察了不同细菌接种量、培养基中血清浓度、培养基的不同ｐＨ值等对罗红霉素体外抗菌作用的影响．体内的保护实验结果表明：本品对接种金黄色葡萄球菌的小鼠口服给药的ＥＤ５０为５．６６ｍｇ／ｋｇ，对接种肺炎链球菌的小鼠口服给药的ＥＤ５０为１７．７７ｍｇ／ｋｇ．     

11-Chloro-3-methyl-3H-imidazo[4,5-a]acridine (CMIA) as a potent and selective antimicrobial agent against clinical isolates of highly antibiotic-resistant Acinetobacter baumannii

Acinetobacter baumannii is an increasingly nosocomial pathogen throughout the world, and the occurrence of multidrug-resistant (MDR) species is increasing. The aim of this study is to present the antimicrobial effects of a newly synthesized imidazoacridine, 11-chloro-3-methyl-3H-imidazo(4,5-a)acridine (CMIA), against MDR clinical isolates of A. baumannii. Standard dilution tube-test assay was performed to determine the MBC of CMIA for 91 clinical isolates of highly antibiotic-resistant bacteria with 28 of A. baumannii in them. The MBCs of CMIA ranged from 2.0 to 10.9?mg/l for Acinetobacter isolates while it was more than 47.9?mg/l for other clinical strains. The findings demonstrate that CMIA is a potent and selective antimicrobial agent against clinical strains of antibiotic-resistant A. baumannii.     

三种中药对解脲支原体的体外抑制实验研究

目的本研究分析了莪术、鱼腥草、土茯苓三种中药对解脲支原体（Uu）临床分离株的体外抑菌作用,并确定了它们的最小抑菌浓度（MIC）。方法采集临床标本,在体外培养获得Uu临床分离菌株,将三种中药各制成药液,用微量稀释法测定各中药对Uu临床分离菌株的最小抑菌浓度。结果鱼腥草MIC为3．90mg／mL,莪术MIC为3．90mg／mL,土茯苓MIC为7．81mg／mL。结论三种中药对uu临床分离菌株均显示较好的体外抑制作用,效果以鱼腥草最佳,莪术次之,土茯苓最后。     

Antifungal Properties of Some Components of Senna Alata Flower

Antifungal activity of some components of Senna alata flower was examined against five fungi. The methanolic crude extract and the partially purified fractions were both active against standard strains of Aspergillus niger, Geotricum candidum, and Candida utilis, and local isolates of Aspergillus brevipes and Penicillium species, but at different concentrations. The minimum inhibitory concentration of the methanolic crude extract was low for all the fungal strains except Aspergillus niger with 5.0 mg/mL concentration, while the minimum inhibitory concentration of partially purified components (C and F) ranged between 0.312 mg/mL for extract F against Penicillium species and 2.5 mg/mL for extract C against Aspergillus niger, Penicillium species and Candida utilis. The minimum fungicidal concentration of the crude methanolic extract was generally higher than 5 mg/mL for most of the fungi but the partially purified extract exhibited fungicidal concentrations ranging from 2.5 mg/mL to 5.0 mg/mL. Antifungal properties against mycelial growth was also demonstrated by all the extracts against the tested strains, with the crude methanolic extract losing its activity after 48 hours. The partially purified Senna alata extracts exhibited a relatively high antifungal activity against mycelial growth with total suppression of sporulation for four days at a concentration of 2 mg/mL, while preventing fungal growth after the seventh day.     

In vitro activity of doripenem against Acinetobacter baumannii clinical isolates

Doripenem is a carbapenem with activity against Gram-positive and Gram-negative pathogens. This study evaluated the in vitro activity of doripenem against a collection of 87 Acinetobacter baumannii clinical isolates, showing that the activity of doripenem was superior to imipenem and meropenem for strains carrying the bla(OXA-58) gene. A. baumannii clinical isolates expressing the bla(OXA-24) gene were resistant to doripenem, imipenem and meropenem. However, in clinical isolates expressing the bla(OXA-58) gene, the percentage of isolates with a doripenem minimum inhibitory concentration >8microg/mL was much lower than that of imipenem and meropenem. This study shows that the activity of doripenem was superior to imipenem and meropenem for strains carrying the bla(OXA-58) gene.     

25种精油对结核分支杆菌的体外药敏试验

通过体外试验,测试25种精油对结核分枝杆菌的最小抑菌浓度即MIC.选择常见的25种精油分别对结核分枝杆菌的标准菌株H37RV、临床药物敏感菌株和临床耐多药菌株,进行体外液态抑菌试验,根据药敏结果,判断精油对结核分枝杆菌的最小抑菌浓度即MIC.通过气态抑菌实验,检测精油气态抑菌MIC.液态抑菌试验结果表明,25种精油对结...     

In vitro activity of MSI-78 alone and in combination with antibiotics against bacteria responsible for bloodstream infections in neutropenic patients

MSI-78 is a 22 amino acid amphipathic peptide with potent antimicrobial activity against Gram-positive and Gram-negative organisms, including antibiotic-resistant strains. In this study, we assessed the in vitro activity of MSI-78 alone and in combination with eight clinically used antimicrobial agents against several strains of Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli isolated from blood of neutropenic febrile patients. Antimicrobial activity of MSI-78 was measured by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill studies and checkerboard titration method. The Gram-negative isolates were susceptible to the peptide at concentrations in the range 0.50-16 mg/L, while staphylococci showed lower susceptibility. MSI-78 demonstrated a higher antimicrobial activity than colistin against Gram-negative organisms. The checkerboard titration method demonstrated synergy when the peptide was combined with beta-lactams. These results provide evidence for the potential use of MSI-78 in the management of severe infections in neutropenic patients.     

In vitro activity of tigecycline (GAR-936) and other antimicrobials against tetracycline- and ciprofloxacin-resistant Campylobacter clinical isolates

During 2003 in our hospital, 236 clinical faecal Campylobacter spp. were isolated, of which 166 (70%) were resistant to tetracycline and 199 (84%) were resistant to ciprofloxacin by the disk diffusion method. Resistance to both antimicrobial agents was found in 146 isolates (62%). The in vitro activity of tigecycline was compared with that of erythromycin, clindamycin and amoxicillin/clavulanic acid using the agar dilution method against 116 selected Campylobacter spp. that were resistant to both tetracycline and ciprofloxacin. The minimum inhibitory concentration at which 90% of the isolates were inhibited (MIC90) was 0.06 mg/L for tigecycline and 4, 2 and 1 microg/mL for amoxicillin/clavulanic acid, erythromycin and clindamycin, respectively. The high in vitro activity of tigecycline against tetracycline- and ciprofloxacin-resistant strains suggests a potential therapeutic role in the treatment of infections that involve Campylobacter spp.     

Sitafloxacin resistance in Helicobacter pylori isolates and sitafloxacin-based triple therapy as a third-line regimen in Japan

The third-line treatment regimen for Helicobacter pylori after failure of clarithromycin- and metronidazole-based therapies is not yet established. Sitafloxacin (STX) is a quinolone that possesses potent in vitro activity against H. pylori. In this study, the susceptibility of H. pylori isolates to STX was examined and the efficacy of STX-based triple therapy as a third-line regimen was evaluated. STX showed minimum inhibitory concentrations (MICs) of ≤1 μg/mL against all 100 H. pylori isolates, and the MIC(90) (MIC for 90% of the organisms) of STX was 5 log(2) dilutions lower than that of levofloxacin (LVX). The MIC(50) (MIC for 50% of the organisms) of STX against gyrA mutants was 0.12 μg/mL and was significantly lower than that of LVX (8 μg/mL). The activity of STX at pH 5.5 was significantly less than that at pH 7.0. In the clinical trial, 28 patients with two eradication failures were treated with STX-based triple therapy [rabeprazole 10 mg twice daily (b.i.d.), amoxicillin 750 mg b.i.d. and STX 100mg b.i.d. for 7 days]. The eradication rate was 75% using intention-to-treat analysis and 80% using per-protocol analysis. Two gyrA mutant strains were eradicated. Amongst participants, a low pepsinogen I/II ratio was associated with successful eradication. These results suggest that STX could be active against most clinical H. pylori isolates and that STX-based triple therapy is a promising and safe third-line therapy.     

In vitro activity of BAL30072 against Burkholderia pseudomallei

Burkholderia pseudomallei is an intrinsically antibiotic-resistant Category B priority pathogen and the aetiological agent of melioidosis. Treatment of B. pseudomallei infection is biphasic and lengthy in order to combat the acute and chronic phases of the disease. Acute-phase treatment preferably involves an intravenous cephalosporin (ceftazidime) or a carbapenem (imipenem or meropenem). In this study, the anti-B. pseudomallei efficacy of a new monosulfactam, BAL30072, was tested against laboratory strains 1026b and 1710b and several isogenic mutant derivatives as well as a collection of clinical and environmental B. pseudomallei strains from Thailand. More than 93% of the isolates had minimal inhibitory concentrations (MICs) in the range 0.004-0.016 μg/mL. For the laboratory strain 1026b, the MIC of BAL30072 was 0.008 μg/mL, comparable with the MICs of 1.5 μg/mL for ceftazidime, 0.5 μg/mL for imipenem and 1 μg/mL for meropenem. Time-kill curves revealed that BAL30072 was rapidly bactericidal, killing >99% of bacteria in 2 h. BAL30072 activity was not significantly affected by efflux, it was only a marginal substrate of PenA β-lactamase, and activity was independent of malleobactin production and transport and the ability to transport pyochelin. In summary, BAL30072 has superior in vitro activity against B. pseudomallei compared with ceftazidime, meropenem or imipenem and it is rapidly bactericidal.