临床分离志贺菌耐药性分析及1类整合子的检测

目的了解2007年至2010年安徽省临床分离志贺菌耐药性和1类整合酶基因(intⅠ1)、qacE△1-sul1基因及整合子携带的耐药基因盒的分布。方法琼脂稀释法检测21种抗菌药物对志贺菌的最低抑菌浓度。PCR扩增intⅠ1和qacE△1-sul1基因,对阳性菌株可变区基因盒序列进行分析。结果 137株志贺菌对萘啶酸、氨苄西林、磺胺甲噁唑/甲氧苄啶的耐药率均80.0%以上,且多重耐药率达94.2%,但对三代头孢菌素和氟喹诺酮类耐药率在33.0%以下。intⅠ1的检出率为89.1%(122/137),检出dfrA17-aadA5和aar-3-aacA4两种基因盒,首次在志贺菌中检测到aar-3-aacA4基因,GenBank登录号JF271916。结论安徽省临床分离志贺菌多重耐药现象严重。临床仍可选用氟喹诺酮类和三代头孢菌素作为本地区细菌性痢疾的经验性治疗。1类整合子与志贺菌的耐药具有一定的相关性。     

天津地区志贺菌耐药性及整合子携带调查

目的:了解天津地区志贺菌抗生素耐药性变迁及1、2类整合子携带状况。方法:K-B纸片法测定1981—1983年及2009年天津地区临床分离的57株志贺菌药敏情况。以煮沸法制备细菌总DNA作为PCR扩增模板。PCR方法扩增1、2类整合子整合酶及可变区并测序分析。PCR产物直接测序,结果经BLAST程序与GenBank数据库标准菌株比对分析。结果:1981—1983年组志贺菌对四环素、链霉素、氯霉素及复方新诺明敏感率低,3种及3种以上抗生素多重耐药率为66.67%;2009年组志贺菌对氨苄西林、链霉素、复方新诺明、哌拉西林和四环素敏感率低,3种及3种以上抗生素多重耐药率为83.33%。1981—1983年组1类整合子阳性率为87.88%(29/33),27株可变区含氨基糖苷类药物耐药基因aadA;1株宋内志贺菌可变区含甲氧苄啶耐药基因dfrA17和氨基糖苷类药物耐药基因aadA5;未发现2类整合子阳性株;2009年组1类整合酶阳性率为79.17%(19/24),可变区及3末端扩增均阴性;2类整合子阳性率87.50%(21/24),可变区含dfrA1+sat1+aadA1,介导甲氧苄啶、链丝菌素和链霉素耐药;其中17株1、2类整合酶均阳性。结论:2009年分离的志贺菌抗生素耐药较上世纪80年代分离的志贺菌增强,多重耐药菌株增加。天津地区志贺菌携带1、2类整合子。′     

产AmpC酶大肠埃希菌中整合子的研究

目的:观察25株产AmpC酶大肠埃希菌中整合子的分类、结构及其在介导AmpC酶基因转移中的作用。方法:采用微量稀释法测定20种抗生素对试验菌株的敏感性。利用多重聚合酶链反应(PCR)方法检测整合酶基因(intI)及其定位,对其阳性菌株可变区(Int)扩增产物进行测序分析。结果:这25株菌对多种抗生素耐药。20株Ⅰ类整合酶基因阳性(80%);所携带的耐药基因盒绝大多数为aadA5和dfr17;未发现携带AmpC基因盒的整合子。结论:Ⅰ类整合子广泛地存在于产AmpC酶的大肠杆菌中;耐药基因盒是整合子阳性菌株对氨基糖苷类、磺胺类药物及氯霉素耐药的主要原因,但对介导AmpC酶基因转移,不起主要作用。     

59株大肠杆菌中整合子的研究

目的:研究59株耐头孢西丁大肠杆菌整合子的分类、结构及其在介导耐药中的作用。方法:利用多重聚合酶链反应(PCR)方法检测整合酶基因(intI),对其阳性菌株可变区(Int)扩增产物进行测序分析;采用微量稀释法测定22种抗生素对试验菌株的敏感性。结果:59株大肠杆菌中,45株Ⅰ类整合酶基因阳性(76%);所携带的耐药基因盒绝大多数为aadA5和dfr17;仅有2株携带β-内酰胺酶耐药基因盒;整合子阳性组抑菌浓度明显高于阴性组。结论:Ⅰ类整合子广泛地存在于耐头孢西丁大肠杆菌中;耐药基因盒是整合子阳性菌株对氨基糖苷类、磺胺类药物及氯霉素耐药的主要原因,但对介导β-内酰胺类耐药方面,不起主要作用。     

多重耐药临床菌株中整合子结构的检测与分析

目的研究广州暨南大学附属第一医院2004年部分临床菌株样本的整合子及其基因盒的分布特性。方法多重PCR检测与细菌耐药关系密切的1、2、3类整合酶基因,进一步对阳性样本可变区的基因盒序列鉴定分析。结果随机抽取109株临床菌株,整合酶阳性检出率为97.2%(106/109),其中1类整合酶阳性菌100株(91.7%),2类整合酶阳性菌1株(0.92%),此外有5株(4.6%)同时检出1、2类整合酶,没有检测到3类整合酶;基因盒鉴定结果显示,插入基因盒以dfrA(甲氧苄氨嘧啶耐药相关)和aadA(氨基糖苷类耐药相关)基因家族为主,也在少数菌株中发现了aacA4、cmlA1、catB3以及sat1基因盒。其中又以dfrA12、orfF和aadA2组合最为常见,耐药基因盒PCR扩增片段为1913bp(64.6%);此外,还发现了同时存在两种整合子结构的菌株。结论整合子普遍存在于临床菌株中,可通过基因水平转移在不同菌属间传播,提示各医药单位必须加强耐药监测及合理选择抗菌药物,以减少多重耐药细菌的发生和发展。     

儿童志贺菌Ⅰ类整合子及与产超广谱β-内酰胺酶基因关系的研究

目的：研究儿童志贺菌Ⅰ类整合子表达及其与产超广谱β-内酰胺酶（ESBLs）基因的相关性。方法：采用PCR方法检测60株产ESBLs志贺菌基因分型以及检测60株产ESBLs与60株非ESBLs志贺菌Ⅰ类整合酶基因,以分析Ⅰ类整合子与细菌耐药性的关系以及与ESBLs基因的关系。结果：儿童临床产ESBLs志贺菌耐药基因分型以CTX-M型最多见（85.0%）,其次为TEM-1型（50.0%）。产ESBL菌株基因分型分布情况以CTX-M型最多见（56.7%）,其次为TEM-1+CTX-M型（20.0%）和TEM-1型（20.0%）。产ESBLs和非产ESBLs菌株中Ⅰ类整合酶扩增阳性例数分别是55例（91.7%）和15例（25.0%）,两组整合子阳性率比较差异有统计学意义（P<0.01）,同时Ⅰ类整合子表达与ESBLs具有相关性（R=0.67,P<0.01）;Ⅰ类整合子阳性的菌株耐药性明显高于Ⅰ类整合子阴性的菌株,整合子阳性株对环丙沙星、左氧氟沙星以及复方磺胺甲噁唑耐药率较高,依次为84.3%、58.6%和90.0%。结论：儿童产ESBLs志贺菌中Ⅰ类整合子携带率明显高于ESBLs阴性菌株,显示儿童志贺菌Ⅰ类整合子与ESBLs基因之间存在密切相关性。     

奇异变形菌中整合子分布及耐药性分析

目的 了解院内奇异变形菌中各类整合子的携带分布情况、阳性菌株可变区基因盒类型以及其与宿主菌耐药表型的相关性,从而为临床治疗和院内感染控制提供参考。方法 采用PCR扩增和琼脂糖凝胶电泳等方法,将本院2016年1月—2018年12月份从临床标本中分离得到的150株奇异变形菌进行第1、2和3类整合子的筛选,并对整合子阳性菌株可变区进行测序分析以及宿主菌的耐药性进行相关性分析。结果 150株奇异变形菌中携带整合子的菌株共有91株,阳性率为60.7%,其中第1类整合子阳性菌株有30株,占20.0%;第2类整合子阳性菌株22株,占14.7%;同时携带第1和2类菌株39株,占26.0%;未筛出第3类整合子;在91株整合子阳性菌株中,86株可变区出现扩增产物条带,其余5株可变区未见扩增产物;第1类整合子阳性菌株可变区携带的耐药基因盒主要为AadA2、DfrA32,第2类整合子阳性菌株可变区携带耐药基因盒主要为DfrA1;可变区携带AadA2的菌株对庆大霉素和妥布霉素的耐药率显著高于整合子阴性菌株(P<0.01),可变区携带DfrA1或DfrA32的菌株对复方磺胺甲噁唑(即甲氧苄啶/磺胺甲噁唑)的耐药率也明显高于整合子阴性菌株(P<0.01);91株整合子阳性菌株对氨苄西林/舒巴坦、复方磺胺甲噁唑、环丙沙星、庆大霉素、头孢曲松、妥布霉素和左氧氟沙星的耐药率均显著高于整合子阴性菌株(P<0.01)。结论 临床分离的奇异变形菌携带整合子的比例较高,其可变区所携带的耐药基因主要为编码氨基糖苷类和甲氧苄氨嘧啶类抗菌药物的基因,整合子的携带与宿主菌产生的耐药性呈高度相关。     

鲍曼不动杆菌Ⅰ类整合子与多重耐药相关性研究

目的 了解临床分离鲍曼不动杆菌的耐药状况、Ⅰ类整合子的分布情况,探讨Ⅰ类整合子与多重耐药的关系.方法 检测20种临床常用抗菌药物对鲍曼不动杆菌临床分离株的最低抑菌浓度(MIC).PCR扩增Ⅰ类整合酶基因.对部分Ⅰ类整合酶阳性菌株进行耐药基因盒序列分析.结果 鲍曼不动杆菌呈现多重耐药,鲍曼不动杆菌对IMP和MRP耐药率分别为0.9%和1.8%,对CPZ/SB的耐药率为35.7%,对其它抗菌药物的耐药率均大于60%,多重耐药率为76.8%(86/112),但对COL和MIN均敏感.80.4%(90/112)的菌株检测出Ⅰ类整合子.Ⅰ类整合子阳性株对多种药物的耐药率均高于阴性株,且Ⅰ类整合子阳性株多重耐药率(90%)明显高于阴性株(22.7%)(P<0.01).Ⅰ类整合子基因盒序列分析显示,Ⅰ类整合子携带aacA4,catB8和aadA13种耐药基因.结论 Ⅰ类整合子在鲍曼不动杆菌中检出率很高并与其多重耐药性关系密切.     

奇异变形菌中整合子分布及耐药性分析

目的 了解院内奇异变形菌中各类整合子的携带分布情况、阳性菌株可变区基因盒类型以及其与宿主菌耐药表型的相关性,从而为临床治疗和院内感染控制提供参考。方法 采用PCR扩增和琼脂糖凝胶电泳等方法,将本院2016年1月—2018年12月份从临床标本中分离得到的150株奇异变形菌进行第1、2和3类整合子的筛选,并对整合子阳性菌株可变区进行测序分析以及宿主菌的耐药性进行相关性分析。结果 150株奇异变形菌中携带整合子的菌株共有91株,阳性率为60.7%,其中第1类整合子阳性菌株有30株,占20.0%;第2类整合子阳性菌株22株,占14.7%;同时携带第1和2类菌株39株,占26.0%;未筛出第3类整合子;在91株整合子阳性菌株中,86株可变区出现扩增产物条带,其余5株可变区未见扩增产物;第1类整合子阳性菌株可变区携带的耐药基因盒主要为AadA2、DfrA32,第2类整合子阳性菌株可变区携带耐药基因盒主要为DfrA1;可变区携带AadA2的菌株对庆大霉素和妥布霉素的耐药率显著高于整合子阴性菌株(P<0.01),可变区携带DfrA1或DfrA32的菌株对复方磺胺甲噁唑(即甲氧苄啶/磺胺甲噁唑)的耐药率也明显高于整合子阴性菌株(P<0.01);91株整合子阳性菌株对氨苄西林/舒巴坦、复方磺胺甲噁唑、环丙沙星、庆大霉素、头孢曲松、妥布霉素和左氧氟沙星的耐药率均显著高于整合子阴性菌株(P<0.01)。结论     

辽宁地区沙门菌整合子与耐药相关性研究

摘要：目的 及时掌握辽宁地区沙门菌整合子的分布以及对常用抗菌药物的耐药情况,获取沙门菌整合子与耐药性的相关性,从而为临床用药及治疗提供指导。方法 本文对来源于食品以及病患的149株沙门菌,利用PCR扩增的方法,进行整合子类别的筛选,并将扩增的整合子基因盒进行基因测序,同时通过药敏板测定(耐药性实验)对沙门菌与15种临床常用抗菌药物的耐药相关性进行研究。结果 149株沙门菌中未发现第II类、第III类整合子,检出第I类整合子的菌株50株,I类整合子阳性率为33.6%。50株整合子阳性菌株中25株携带耐药基因盒,片段范围从1500~1800 bp。测序结果表明,其中22株整合子携带dfrA17-aadA5基因盒,2株携带dfrA12-aadA2基因盒,1株首次检出罕见耐药基因盒linG。根据整合子携带情况不同,对15种抗菌药物的耐药率进行对比分析,结果显示整合子阳性菌对9种抗菌药物的耐药率显著高于整合子阴性菌(P<0.01),分别为氨苄西林、四环素、氯霉素、头孢噻肟、头孢唑林、庆大霉素、复方磺胺甲恶唑、阿奇霉素和环丙沙星。辽宁地区沙门菌多重耐药率达50.3%。结论 I类整合子在沙门菌中分布广泛,抗性基因表型与耐药结果相一致,整合子的携带与沙门菌多重耐药率高度相关。沙门菌对亚胺培南和头孢西丁保持高敏感率,可以用于对常规抗菌药物耐药的沙门菌的治疗。     

1,3-dioxolane-based ligands as a novel class of alpha1-adrenoceptor antagonists

1,3-Dioxolane-based compounds (2-14) were synthesized, and the pharmacological profiles at alpha(1)-adrenoceptor subtypes were assessed by functional experiments in isolated rat vas deferens (alpha(1A)), spleen (alpha(1B)), and aorta (alpha(1D)). Compound 9, with a pA(2) of 7.53, 7.36, and 8.65 at alpha(1A), alpha(1B), and alpha(1D), respectively, is the most potent antagonist of the series, while compound 10 with a pA(2) of 8.37 at alpha(1D) subtype and selectivity ratios of 162 (alpha(1D)/alpha(1A)) and 324 (alpha(1D)/alpha(1B)) is the most selective. Binding assays in CHO cell membranes expressing human cloned alpha(1)-adrenoceptor subtypes confirm the pharmacological profiles derived from functional experiments, although the selectivity values are somewhat lower. Therefore, it is concluded that 1,3-dioxolane-based ligands are a new class of alpha(1)-adrenoceptor antagonists.     

2-Aminobenzophenones as a novel class of bradykinin B1 receptor antagonists

Selective bradykinin (BK) B 1 receptor antagonists could be novel therapeutic agents for the treatment of pain and inflammation. Elucidation of the structure activity relationships of the structurally novel HTS lead compound 1 provided potent hBK B 1 receptor antagonists with excellent receptor occupancy in the CNS of hBK B 1 transgenic rats.     

7-Aroyl-aminoindoline-1-sulfonamides as a novel class of potent antitubulin agents

A novel series of 7-aroyl-aminoindoline-1-benzenesulfonamides showed excellent activity as inhibitors of tubulin polymerization through binding with the colchicine binding site of microtubules. Compound 15 and 16 display IC50 values of 1.1 and 1.2 microM, respectively. Compound 15 inhibited the human cancer cell growth of KB, MKN45, H460, HT29, and TSGH, as well as one human-resistant cancer line of KB-vin 10, with an IC50 of 9.6, 8.8, 9.4, 8.6, 10.8, and 8.9 nM, respectively.     

2,4,6-trisubstituted pyrimidines as a new class of selective adenosine A1 receptor antagonists

Adenosine receptor antagonists usually possess a bi- or tricyclic heteroaromatic structure at their core with varying substitution patterns to achieve selectivity and/or greater affinity. Taking into account molecular modeling results from a series of potent adenosine A1 receptor antagonists, a pharmacophore was derived from which we show that a monocyclic core can be equally effective. To achieve a compound that may act at the CNS we propose imposing a restriction related to its polar surface area (PSA). In consequence, we have synthesized two novel series of pyrimidines, possessing good potency at the adenosine A1 receptor and desirable PSA values. In particular, compound 30 (LUF 5735) displays excellent A1 affinity (Ki = 4 nM) and selectivity (< or =50% displacement of 1 muM concentrations of the radioligand at the other three adenosine receptors) and has a PSA value of 53 A2.     

2-Phenylpyrroles as conformationally restricted benzamide analogues. A new class of potential antipsychotics. 1

2-Phenylpyrroles were synthesized as conformationally restricted analogues of the substituted benzamide sultopride and the butyrophenones haloperidol and fluanisone. Dopamine antagonistic activity is maintained if the 2-phenylpyrrole side chain is linked to the pharmacophoric N-ethylpyrrolidine moiety of sultopride or to the 4-substituted piperazine moiety of fluanisone but is lost if the 2-phenylpyrrole is combined with the 4-substituted piperidine moiety of haloperidol. The 2-phenylpyrrole analogue 1 of sultopride is in vitro 0.25 and in vivo 3 times as potent as the parent compound. Its binding to the dopamine D-2 receptors is, in analogy to the substituted benzamides, strongly sodium-dependent. The 2-(4-fluorophenyl)pyrrole analogue 5 of fluanisone is superior in vitro as well as in vivo to the corresponding benzamide 7 and the butyrophenone fluanisone. The increase in activity is not only due to a higher affinity for the D-2 receptors but also to an enhanced oral absorption (ratio po/ip = 4.5 vs 40 for the benzamide and 60 for fluanisone). Compound 5 is further characterized by a high selectivity for the D-2 receptors, in contrast to the benzamide and butyrophenone analogues (ratio D-2/alpha 1 = 60, 2.0, and 0.3, respectively). The binding to the D-2 receptors has little dependence on sodium. The 2-phenylpyrrole 5 shares with the benzamide 7 a low potential to induce catalepsy, which is in contrast to haloperidol. So, 5-(4-fluorophenyl)-2-[[4-(2-methoxyphenyl)-1-piperazinyl]methyl]pyrrole (5) is the prototype of a new class of sodium-independent dopamine D-2 antagonists, which may be particularly useful as potential antipsychotics with a low propensity to induce acute extrapyramidal side effects.     

Norpiperidine imidazoazepines as a new class of potent, selective, and nonsedative H1 antihistamines

Clinical doses of available H(1) antihistamines are limited mainly by sedative side effects. However, higher doses are often required to obtain optimal therapeutic activity, especially in dermatology. We report the synthesis of three norpiperidine imidazoazepines representative of a new class of selective and nonsedating H(1) antihistamines. The compounds were at least as potent as cetirizine and loratadine as measured by H(1) receptor binding affinity, by protection against compound 48/80- and histamine-induced lethality in rats and guinea pigs, respectively, and by skin reaction tests in rats, guinea pigs, and dogs. The compounds, in particular 3a, were less prone than the reference compounds to penetrate the brain and to occupy central H(1) receptors, suggesting absence of sedative side effects. In vitro and in vivo cardiovascular safety tests showed that 3a had no intrinsic potential to prolong ventricular repolarization or induce cardiac arrhythmias. Compound 3a has been selected for further clinical development, mainly for application in dermatology.     

Synthesis and biological evaluation of 1-cyano-2-amino-benzimidazole derivatives as a novel class of antitumor agents

A series of 1-cyano-2-amino-benzimidazole derivatives were synthesized and evaluated for their cytotoxic activities in vitro against three human cancer cell lines (human lung carcinoma cell line: A549, human leukemia cell line: K562, and human prostate cancer cell line: PC-3). Most of these compounds showed potent activities against these tumor cell lines, especially against A549 and K562 cell lines. The preliminary structure–activity relationships of 1-cyano-2-amino-benzimidazole derivatives were also discussed. The cell cycle analysis was carried out in K562 cells and the results showed that compound 4d caused a marked increase of cells in G ₂/M phase.     

1-alkyl-4-acylpiperazines as a new class of imidazole-free histamine H(3) receptor antagonists

With the aim of identifying structurally novel, centrally acting histamine H(3) antagonists, arrays of monoacyldiamines were screened. This led to the discovery of a series of 1-alkyl-4-acylpiperazines which were potent antagonists at the human histamine H(3) receptor. The most potent amides had antagonist potencies in the subnanomolar range.     

Synthesis and biological evaluation of 1-benzylidene-3,4-dihydronaphthalen-2-one as a new class of microtubule-targeting agents

A series of 1-benzylidene-3,4-dihydronaphthalen-2-one derivatives were designed and synthesized, and their biological activities in vitro and in vivo were evaluated. The results showed a number of the title compounds exhibiting potent nanomolar activity in several human cancer cell lines. Of these, compound 22b showed the strongest inhibitory activity against human CEM, MDA-MBA-435, and K562 cells (IC(50) = 1 nM), displayed in vitro inhibition of tubulin polymerization (IC(50) = 3.93 μM), and significantly induced cell cycle arrest in G2/M phase. In addition, compound 22b could inhibit the tumor growth in colon nude mouse xenograft tumor model significantly and seemed safer than CA-4 when achieving a similar tumor suppression. This study provided a new molecular scaffold for the further development of antitumor agents that target tubulin.     

HIV co-receptor inhibitors as novel class of anti-HIV drugs

Entry inhibitors constitute a new class of drugs to treat infection by human immunodeficiency virus type 1 (HIV-1). The first member of this class, enfuvirtide, previously known as T-20 and targeting gp41, has now been licensed for therapeutic use. Several other entry inhibitors are in various stages of pre-clinical or clinical development. In this review we focus on the chemokine receptor inhibitors targeting CCR5 and CXCR4 that are the main HIV co-receptors for viral entry.