MTB新疆临床分离株MDR-TB和XDR-TB耐药情况初步调查

目的:分析新疆喀什地区结核分枝杆菌(MTB)临床分离株对4种一线和7种二线抗结核药物的耐药情况,初步探讨本地区耐多药结核病(MDR-TB)和广泛耐药结核病(XDR-TB)的流行情况。方法:收集2008.11.1~2009.10.31日期间新疆喀什地区结核病患者痰液标本,进行分离培养及菌种鉴定,并应用比例法对所分离得到的菌株进行耐药性检测。结果:102株分枝杆菌中,88株(86.3%)属于结核分枝杆菌复合群,7株(6.9%)属于牛型分枝杆菌,7株(6.9%)属于非结核分枝杆菌。对一种以上的抗结核药物具有耐药性的有20株,总耐药率为22.7%(20/88),耐多药率为6.8%(6/88),pre-XDR为33.3%(2/6),无XDR-TB病例。结论:新疆喀什地区结核病患者耐药率较高,在结核病治疗工作中应给予重视,尤其应加强对Pre-XDR的重视,以免发展成XDR-TB。     

儿童结核病耐药状况及危险因素分析

目的了解最新儿童耐药结核病流行现状,为耐药儿童结核病的预防、控制提供依据。方法于2006年6月至2009年6月间收集了重庆医科大学附属儿童医院161例结核病患儿样本,采用比例法对链霉素(Streptomycin,SM)、异烟肼(Isoniazide,INH)、利福平(Rifampicin,RFP)、乙胺丁醇(Ethambutol,EMB)和吡嗪酰胺(Pyrazinamide,PZA)共5种药物进行耐药性测定。结果 161株菌株中鉴定出139例为结核分枝杆菌,对这139例培养阳性儿童结核病例中,总耐药率和总耐多药率分别为20.86%、6.47%,平均耐药率顺位由高到低是SM(12.2%)、INH(10.79%)、RFP(8.63%)、EMB(2.88%)、PZA(2.88%)。结论重庆地区儿童结核病总体耐药及耐多药水平低于全国平均水平,城镇地区及复治患儿可能是儿童结核病病例发生多耐药的相关因素。     

结核分枝杆菌乙胺丁醇耐药机制的研究进展

耐多药结核病的出现和流行对结核病的防控造成了严重威胁。乙胺丁醇(Ethambutol, EMB)是一线抗结核药物,常与异烟肼、利福平等联合应用,还可用于耐药结核病的治疗。但近年来EMB耐药形势严峻,我国复治结核病患者中EMB耐药率已达17.2%,并呈上升趋势;耐多药结核病患者中,EMB耐药率约为51.3%~66.7%,情况不容乐观。明确EMB耐药的产生机制对于有效防控EMB耐药率的上升、充分发挥EMB的作用十分重要,因此本文对结核分枝杆菌EMB的耐药现状、EMB的作用机制及其耐药产生机制方面的研究进展进行了综述。     

重症监护室耐亚胺培南鲍曼不动杆菌的耐药性分析

目的探讨温州医学院附属第一医院重症监护室（ICU）耐亚胺培南鲍曼不动杆菌的耐药特性。方法对2006年1月至2007年12月ICU分离的菌株采用常规方法进行菌株分离,经革兰染色、氧化酶试验等初筛,再经VITEK-32型全自动微生物分析仪进行菌株鉴定和药敏试验。结果共检测到98株鲍曼不动杆菌,其中耐亚胺培南的鲍曼不动杆菌为50株（占51.0%）,标本来源大部分为痰液（占94.9%）。耐亚胺培南鲍曼不动杆菌对常用16种抗菌药物耐药率〉50%的有15种,耐药率〉90%有3种,分别为氨苄西林（98.0%）、头孢唑林（99.0%）和呋喃妥因（99.0%）,对抗菌药物耐药率最低仅为头孢哌酮/舒巴坦（10.2%）,另外检测到对所用抗菌素泛耐为4株（8.0%）;而对亚胺培南敏感的鲍曼不动杆菌对常用16种抗菌药物耐药率〉50%的仅为4种,耐药率〉90%同样为氨苄西林（100%）、头孢唑林（97.9%）和呋喃妥因（97.9%）,耐药率比较低的为美罗培南（10.4%）、妥布霉素（16.7%）和环丙沙星（16.7%）,耐药率最低也为头孢哌酮/舒巴坦（6.3%）。结论 ICU分离耐亚胺培南鲍曼不动杆菌多重耐药性严重,出现了泛耐菌株;临床可根据药敏试验选用抗菌药物,一般条件下耐亚胺培南鲍曼不动杆菌建议选用头孢哌酮／舒巴坦。     

新疆南疆MTB临床分离株异烟肼耐药情况及耐药相关基因的突变研究

目的:探索新疆南疆部分地区维吾尔族结核病人群中分离到的结核分枝杆菌基因组中的katG、inhA、kasA、ahpC基因突变与耐异烟肼的关联,揭示新疆肺结核病高患病率、高死亡率的可能原因.方法:收集新疆南疆部分地区维吾尔族结核病患者痰液标本,对MTB进行分离培养后,应用比例法检测其对异烟肼耐药性,运用PCR技术对所分离菌株的上述基因相关片段扩增并进行测序及序列分析.结果:筛选出实验菌株99株,其中敏感株63株,耐异烟肼菌株36株,耐药率为36.4%.耐药株中katG基因突变率为63.9%,315位点突变,突变类型AGC→ACC(Ser→Thr)、AGC→AAC(Ser→Asn);inhA基因突变率为47.2%,有缺失、同义突变和错义突变;kasA基因突变率为41.7%,突变类型为缺失和错义突变;ahpC基因突变率为8.3%,属于错义突变.结论:新疆南疆结核病高患病率、高死亡率的可能原因之一是结核分枝杆菌对INH产生了耐药,结核分枝杆菌对INH耐药机制可能与耐药菌株基因组内katG、inhA、kasA和ahpC基因发生了突变有关.     

不同来源株香港海鸥形菌药敏试验结果分析

目的对分离自社区获得性胃肠炎患者及淡水鱼肠道内的香港海鸥形菌(Laribacter hongkongensis,LH)进行药敏试验,为临床合理使用抗菌药物提供依据。方法2005年至2006年杭州市第一人民医院肠道门诊从社区获得性胃肠炎患者中分离到4株及2种淡水鱼体内10株LH菌株,计14株,按美国CLSI推荐的纸片扩散法进行药敏试验。结果药敏结果显示,14株LH菌株对24种常用抗菌药物中的15种药物,分别表现出不同程度的耐药性,耐药率达62.5%;尤其对青霉素、头孢唑啉和头孢哌酮等3种药物,14株LH菌株均为耐药,耐药率为100.0%;其中人体株LHHZ26,对12种药物耐药、1种为中介。LH对3代头孢表现为较高的耐药性,3种头孢药物的耐药率为71.43%~100%;14株LH株对头孢吡肟及头孢哌酮/舒巴坦均为敏感。对氨曲南(14.29%)、庆大霉素(7.14%)、复方新诺明(7.14%)的耐药率较低;喹诺酮类、氯霉素、阿米卡星、美罗培南、亚胺培南等药物均敏感。结论LH菌株对β-内酰胺类药物表现出耐药性,对青霉素类、头孢菌素类药物广泛耐药。建议对LH感染患者喹诺酮类为首选治疗用药。     

儿科痰培养肺炎链球菌耐药性分析

目的了解厦门市妇幼保健院儿科患者下呼吸道感染肺炎链球菌的耐药情况。方法对厦门市妇幼保健院2007年9月至2009年12月从儿科分离的95株肺炎链球菌用K-B纸片法检测其对青霉素等5种抗菌药物的敏感度,对耐苯唑西林的菌株用E-test法检测青霉素和头孢曲松的MIC值。结果95株肺炎链球菌对红霉素、克林霉素高度耐药,耐药率分别为97.9%、96.8%,对左氧氟沙星几乎敏感,未检出耐万古霉素菌株。E-test法测试青霉素不敏感率为58.9%（56株）,头孢曲松敏感率为93.7%（89株）。ermB因介导的红霉素耐药菌株92株,占98.9%,mefE基因介导的红霉素耐药仅1株（1.1%）。结论厦门市妇幼保健院分离的肺炎链球菌耐药严重,PNSP检出率较高（58.9%）,对红霉素、克林霉素高度耐药,临床应尽量减少此类药物的经验性用药,依据药敏结果选择抗菌药物进行治疗。     

摩根摩根菌β-内酰胺酶检测及耐药性分析

目的了解摩根摩根菌临床分离株产超广谱β-内酰胺酶（ESBLs）、头孢菌素酶（AmpC）、金属酶（MBLs）、碳青霉烯酶（KPC）情况,并分析其对17种常见抗菌药物的耐药性。方法 ESBLs和AmpC及MBLs采用三维试验检测,碳青霉烯酶采用改良Hodge试验进行检测,并以K-B法测定17种常见抗菌药物的耐药性。结果 102株摩根摩根菌单产ESBLs 15株,检出率为14.71%;单产AmpC 8株,检出率为7.84%;单产金属β-内酰胺酶（MBLs）3株,检出率为2.94%;所有菌株中未检出碳青霉烯酶（KPC）;同产ESBLs及AmpC 6株,检出率为5.88%;未发现其他双产酶菌株。摩根摩根菌非产酶分离株对17种抗生素的耐药率均低于50.0%;摩根摩根菌产酶分离株对亚胺培南、美罗培南培南的耐药率低于15.0%,与非产酶菌株相比,差异无统计学意义（P〉0.05）;对其余抗生素的耐药率均明显高于非产酶菌株（P〈0.05）。同产ESBLs＋AmpC与耐亚胺培南摩根摩根菌分离株呈多重耐药。结论我院摩根摩根菌分离株产生多种β-内酰胺酶,且对常用抗生素耐药性比较严重,建议临床医师合理使用抗生素,以免耐药菌株的产生。     

232株金黄色葡萄球菌的临床分布特征及耐药性分析

目的了解金黄色葡萄球菌(金葡菌)临床分离株的感染分布特点及耐药现状,以便为临床感染治疗及预防提供帮助。方法收集南昌大学第二附属医院2007年1月至2009年12月临床分离的非重复金葡菌232株。常规方法进行菌株分离,血浆凝固酶、金葡菌单克隆抗体及Vitek-32型仪进行菌株鉴定,纸片扩散法测定菌株对抗菌药物的敏感性,头孢西丁法检测耐甲氧西林金葡菌(MRSA),WHONET5.5软件分析数据。结果下呼吸道标本中分离的金葡菌最多,占44.0%,其次是脓液(20.3%)和血液(18.1%)。232株金葡菌中共检测到MRSA 131株(56.6%),金葡菌对青霉素的耐药率最高(90.0%),对庆大霉素、左氧氟沙星、克林霉素、红霉素和四环素的耐药率均50.0%;耐药率在10.0%~50.0%的有阿米卡星、复方磺胺甲噁唑和夫西地酸;对替考拉宁耐药率非常低(1.3%);未出现耐万古霉素的菌株。结论下呼吸道及皮肤软组织是金葡菌的主要感染部位;金葡菌对临床常用抗菌药物的耐药率近3年来趋于稳定,糖肽类抗菌药物对其仍有非常强的抗菌活性。     

社区和医院获得性尿道致病性大肠埃希菌耐药性分析

目的了解浙江省社区和医院获得性尿道致病性大肠埃希菌的耐药现状及产超广谱β-内酰胺酶(ESBLs)菌株基因型,为临床合理用药提供科学依据。方法对2014年1月至2014年12月浙江省社区和医院获得性尿道致病性大肠埃希菌耐药情况进行分析,并随机各抽取20株菌株进行CTX-M基因型检测。结果社区和医院获得性大肠埃希菌共收集到93株和992株,产ESBLs菌株的阳性率分别为47.7%和68.5%,差异有统计学意义(P0.05);社区获得性菌株CTX-M基因检出率为30.0%(6/20),其中又以CTX-M-9为主(4/6)。医院获得性菌株CTX-M基因检出率50.0%(10/20),其中CTX-M-9占7/10。医院获得性菌株对头孢呋辛、头孢唑啉、头孢曲松、环丙沙星、左旋氧氟沙星、甲氧苄氨嘧啶/磺胺甲恶唑、呋喃妥因和阿米卡星的敏感率明显低于社区获得性菌株(P0.05)。结论浙江省医院获得性尿道致病性大肠埃希菌对部分抗菌药物的耐药率明显高于社区获得性菌株,ESBLs基因以CTX-M-9为主。     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.     

2016年中国植物科学若干领域重要研究进展

2016年中国植物科学持续稳步发展, 表现在中国植物科学家在国际主流高影响力学术期刊发表文章的数量稳中有升, 中国植物科学领域的期刊逆风出行, 进入研究性期刊世界前三甲行列。中国科学家在植物学诸多领域取得了丰硕的成果。水稻(Oryza sativa)产量性状杂种优势的分子遗传机制解析入选2016年中国科学十大进展; 植物受精过程中雌雄配子体信号识别机制的研究和独脚金内酯的受体感知机制入选2016年生命科学十大进展。我国植物科学, 特别是以水稻为代表的作物研究在国际学术界已占有一席之地。例如, 在水稻组学(如基因组和转录组等)资源和技术平台的建立、重测序的开发及功能基因的克隆和调控网络的解析方面取得了系列重要成果(如揭示了独脚金内酯信号转导的“去抑制化激活”机制、从分子水平上阐释了水稻籼粳杂种不育和广亲和性基因S5的作用机理及发现了控制水稻耐冷的基因组位点), 已经引领世界水稻乃至作物科学研究。该文对2016年中国本土植物科学若干领域取得的重要研究进展进行了概括性评述, 旨在全面追踪当前中国植物科学领域的发展前沿和研究热点, 与读者共享我国科学家所取得的杰出成就。