一株产新型大环内酯抗生素海洋解淀粉芽孢杆菌的分离鉴定

目的 对分离自中国东海30 m深海泥的一株产新型大环内酯抗生素(macrolactin s,MLS)的菌株进行形态、生理生化特性及分子水平的分类学研究.方法 通过细菌培养特征观察,菌株生长条件测定、生理生化指标及全细胞脂肪酸成分分析,并特异性扩增其16S rDNA序列,测序比对及构建系统发育进化树,利用本实验室所建立的抗菌模型评价代谢产物的抗菌活性.结果 该菌株与芽孢杆菌属其他种共享97%～99%的保守序列,其中与解淀粉芽孢杆菌(Bacillus amyloliquefaciens)的16SrDNA序列保守度高达99.6%.15:1 iso H/13:0 3OH为该菌株的主要脂肪酸组分.结论 该菌株属于芽孢杆菌属,定名为解淀粉芽孢杆菌MS1721株,其所产大环内酯MLS表现出较强的抗菌活性.     

姥鲨共附生微生物抗菌活性筛选及系统发育分析

目的 以深海姥鲨鱼鳃和胃肠道共附生微生物为研究对象,对可培养微生物进行分离、纯化和初步鉴定,筛选抗菌活性,为寻找天然活性产物奠定基础.方法 采用倍比稀释涂布和划线法结合分离纯化可培养微生物;以枯草芽孢杆菌、金黄色葡萄球菌、大肠杆菌、铜绿假单胞菌、产气肠杆菌、白色念珠菌为抗菌活性筛选模型,利用琼脂块法和滤纸片法筛选纯培养菌株抗菌活性;利用形态观察、生理生化反应和16S rRNA技术对抑菌活性进行初步鉴定.结果 从姥鲨鱼鳃和胃肠道分离得到的可培养微生物36株,其中来自鱼鳃5株,来自胃肠道31株;菌株统计表明:真菌7株,占19%;放线菌1株,占3%;细菌28株,占78%.对23株来自姥鲨胃肠道的细菌进行抗菌活性筛选,15种表现抗(抑)菌活性,占分离菌株的65%.他们分别隶属于芽孢杆菌属(Bacillus)5株,葡萄球菌属(Staphylococcus)6株,短波单胞菌属(Brevundimonas)2株,嗜冷杆菌属(Psychrobacter)2株.结论 利用常规微生物学技术可以对姥鲨胃肠道和鱼鳃等部位存在共附生微生物分离和纯化,其中超过50%的菌株表现抗(抑)菌效果.     

2006～2011年河南省新生儿血培养分离菌分布及耐药性分析

目的:通过对2006～2011年河南省新生儿重症监护中心(NICU)血液标本细菌感染菌株的分布及感染优势菌的药敏情况进行分析,掌握河南省新生儿血培养分离菌的分布及耐药性情况,为临床抗菌药物的合理选用提供依据.方法:对2006～2011年河南省新生儿重症监护中心新生儿血标本检出阳性菌株采用ATB-Expression系统结合手工方法进行鉴定和MIC法药敏实验,并用纸片扩散法对其中疑难菌株实行体外药敏实验的复查和核实,药敏结果参照CLSI标准判读,将数据录入WHONET软件进行细菌分布和耐药性统计分析.结果:河南省新生儿感染血培养普通型共检出阳性菌2 232株,血培养L型共检出阳性菌24株;阳性菌分布以革兰氏阳球性菌为主,常见菌种依此为凝固酶阴性葡萄球菌1 412株、金黄色葡萄球菌283株、大肠埃希氏菌215株、肺炎克雷伯菌153株.     

闽北地区肝胆管结石细菌感染耐药情况分析

目的探讨闽北地区肝胆管结石患者胆汁的细菌谱及细菌药物敏感性状况。方法对我院自2008年7月—2012年7月收治的330例肝胆管结石的患者进行胆汁细菌培养及药物敏感性试验,并对收集的资料进行统计学分析。结果 330例患者中198例培养阳性,阳性率为60%。共培养菌株207株,其中G-菌126株,占60.9%,G+菌81株,占39.1%。引起胆道感染较为常见的菌属依次为大肠埃希菌属、粪肠球菌属、肺炎克雷伯菌属、铜绿假单胞菌属。G-菌对头孢他啶、头孢哌酮钠-舒巴坦钠、亚胺培南、阿米卡星敏感性较高,G+菌对氨曲南、亚胺培南敏感性较高。结论随着闽北地区各种抗菌药的广泛应用,肝胆管感染细菌谱发生了一定变化,G+菌比例虽有所上升,但G-菌仍占较高比例,且细菌对抗菌药的耐药性有所上升,临床应根据培养结果合理应用抗菌药。     

5.12汶川地震伤员革兰阴性杆菌感染分析

目的:为自然灾害后革兰阴性杆菌感染性疾病的治疗和医院感染控制提供参考依据.方法:对临床送检的地震伤员标本进行常规细菌培养、鉴定和药物敏感性试验,并对所得结果进行统计和分析.结果:地震伤员的感染病原菌以多重耐药的革兰阴性杆菌为主,295例标本共培养出247株细菌,阳性195例(66.10%),革兰阴性杆菌中发现4株全耐药的不动杆菌属细菌、2株克雷伯菌属细菌及2株铜绿假单胞菌及2株荧光假单胞菌,还发现产ESBL的大肠埃希氏菌25株(64.10%)及克雷伯氏菌8株(38.10%).结论:地震灾害后感染性疾病是常见的并发症,伤员在运送途中及住院治疗期间应遵循严格的隔离制度和抗生素准入制度,以防高度耐药的病原菌引起医院感染的爆发和流行.     

氨溴索对铜绿假单胞菌密度感应缺陷株生物膜细菌活力和黏附作用的影响

目的 研究氨溴索对铜绿假单胞菌野生株PAO1及密度感应缺陷株(ΔlasI ΔrhlI基因缺陷)生物膜(BF)细菌活力及早期黏附的影响.方法 利用平板计数法测定不同浓度(0、1.875、3.75mg/ml)氨溴索对PAO1菌株、ΔlasI ΔrhlI菌株生物膜菌落的清除效应;荧光多功能酶标仪检测不同浓度氨溴索作用后PAO1菌株、ΔlasI ΔrhlI菌株的荧光强度,计算黏附率以反映干预对细菌黏附的影响.结果 氨溴索作用后,两种菌株的活菌生存率和黏附率均出现下降,ΔlasIΔrhlI株活菌生存率较PAO1株下降更明显(P＜0.05),而PAO1株黏附率较ΔlasI ΔrhlI株下降更明显(P＜0.05).结论 氨溴索具有拮抗密度感应系统的作用,可用于抗细菌生物膜活力,为难治性铜绿假单胞菌感染的治疗提供了新思路.     

类球红细菌空间诱变效应研究

目的利用空间诱变手段处理类球红细菌,通过诱变后菌株生理生化情况的变化,筛选辅酶Q10(CoQ10)高产菌株,为空间诱变手段筛选产业化菌株的应用提供实验和理论依据。方法利用返回式卫星搭载类球红细菌,检测搭载后菌株的抗逆性及发酵CoQ10能力。结果空间搭载后筛选到生长温度、pH值、盐浓度范围变宽,抗逆性增强的菌株,同时菌落颜色出现乳白色、粉红色等颜色变异菌株。从颜色变浅的变异菌株中筛选到一株CoQ10高产菌,发酵生产CoQ10比对照高73.13%。结论与传统单因素诱变方式相比,空间诱变是多因素综合作用,诱变效果明显,能获得高抗逆性和高CoQ10生产能力的突变株,可以作为产业化菌株筛选的诱变方式。     

模拟微重力环境下细菌生物学效应的初步研究

目的 研究模拟微重力环境下细菌的生物学效应.方法 应用回转器处理实验菌株(大肠杆菌、金黄色葡萄球菌、枯草芽胞杆菌、鼠伤寒沙门氏菌),检测其生长曲线,抗生素敏感性,以及抗生素敏感性变化株与野生株间脂肪酸图谱的差别.结果 模拟微重力条件下,细菌对数期提前、生长曲线形状改变.回转器处理30 d后可检测到大肠杆菌抗生素敏感性突变株,并且突变株的数量与处理时间呈现正相关趋势;鼠伤寒沙门氏菌处理120 d后,检测到氨苄西林和左氧沙星耐受株突变为敏感株;脂肪酸图谱分析显示,突变株与对照株相比脂肪酸的种类和含量存在一定差异.结论 回转器模拟微重力条件下,细菌生物性状受到影响,抗生素敏感性的改变可能与细菌脂肪酸图谱的变化有关.     

中国海域海洋细菌的分离与鉴定方法研究

目的 探讨理想的海洋细菌增菌、分离与鉴定方法.方法 海洋细菌经8种不同种类增菌液增菌后,选择11种不同种类的培养基进行分传,然后挑选单个菌落应用VITEK全自动微生物鉴定仪(VOTEK-AMS)、API微生物鉴定系统和BIOMIC榆测仪进行检测,用微量生化反应管进行手工补充鉴定.结果 从中国四大海域采集的海水中共分离到72种411株细菌与真菌.弧菌为海水中的优势菌(177株,43.1%).弧菌应首选碱性蛋白胨水和嗜盐菌增菌液进行增菌,然后用TCBS平板和血平板进行分传.其他细菌适合用2号营养肉汤增菌后再用血平板和中国蓝平板分离.真菌适合用真菌肉汤液增菌,用沙氏平板进行分传.对所分离的细菌采用VITEK-AMS、API系统和BIOMIC检测仪结合微量生化反应管进行手工补充鉴定,获得了良好的分离效果.结论 对于海洋中不同种类的细菌与真菌,应选用不同种类的增菌液和培养基进行增菌与分离.采用VITEK-AMS、API系统、BIOMIC检测仪结合微量生化反应管进行手工补充鉴定,是较理想的海洋细菌检测方法.     

外科病房常见病原菌及药敏监测结果分析

目的：调研外科病房常见病原菌及其药敏,以指导临床合理用药。方法：采用K-B琼脂扩散法,对外科临床发生感染的标本进行细菌培养,并检测菌株对常用20种抗生素的敏感性。结果：共分离出103株细菌,属前5位的分别是：金黄葡萄球菌、朋肠杆菌、奈瑟氏菌、肠埃希菌、铜绿假单胞菌。药敏结果表明20种常用抗生素均结果为基础,细菌培养前抗菌药物的选择可参考本研究。     

不同脂肪酸构成对大鼠肝脏HMG-CoAR、SREBP-1c表达的影响

目的探讨不同膳食脂肪酸构成比对大鼠脂质代谢相关基因HMG-CoAR、SREBP-1c的mRNA表达的影响。方法雌性SD大鼠随机分成6组,喂养6种不同膳食脂肪酸组成的饲料,即饱和脂肪酸组（SFA）、单不饱和脂肪酸组（MUFA）、n-6多不饱和脂肪酸组（n-6 PUFA）、n-3多不饱和脂肪酸组（n-3 PUFA）、1：1 n-6/n-3组及普通饲料喂养组,持续喂养18 w。并在实验第8 w和18 w时,提取大鼠肝脏组织,利用RT-PCR技术检测大鼠肝脏组织中HMG-CoAR、SREBP-1c mRNA表达状况。结果与对照组相比较,SFA能非常显著地升高HMG-CoAR mRNA的表达（P〈0.01）,MUFA能显著降低HMG-CoAR的基因表达（P〈0.05）,而PUFA则能够显著降低HMG-CoAR和SREBP-1c的基因表达（P〈0.05）。且在相同的总脂肪含量下,n-3 PUFA和n-6/n-3配比的膳食干预效果优于n-6 PUFA。结论 SFA、MUFA主要是通过HMG-CoAR途径来调控机体的脂质代谢,它们对SREBP-1c的表达无明显影响。PUFA调节血脂的作用机制可能与脂代谢基因HMG-CoAR和SREBP-1c有关。     

Comparison of 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA) metabolism and kinetics in the isolated rat heart

Time courses of radioactivity (residue curves) were obtained following bolus injection into working rat hearts of two 125I-labeled long chain fatty acids: 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA). Residue curves were analyzed in terms of a rapid vascular washout component, an early tissue clearance component, and a very slow late component. For IHDA and IPPA in control hearts, early myocardial clearance kinetics were rate limited by the diffusion of catabolites. Sensitivity of the kinetics to impaired fatty acid oxidation was examination by pretreatment of animals with 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). Decreased fatty acid oxidation was indicated in IHDA and IPPA residue curves by a decrease in the relative size of the early clearance component. Analysis of radiolabeled species in coronary effluent and heart homogenates showed that back diffusion of IPPA was slower than that of IHDA; this discrepancy was most apparent in POCA hearts. In vitro binding assays suggested higher tissue:albumin relative affinity for IPPA than for IHDA. Thus, IPPA early clearance kinetics were more closely related to the clearance of labeled catabolite(s) and were therefore more sensitive to the oxidation rate of long chain fatty acids.     

Comparison of 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA) metabolism and kinetics in the isolated rat heart

Time courses of radioactivity (residue curves) were obtained following bolus injection into working rat hearts of two ¹²⁵I-labeled long chain fatty acids: 16-iodohexadecanoic acid (IHDA) and 15-p-iodophenylpentadecanoic acid (IPPA). Residue curves were analyzed in terms of a rapid vascular washout component, an early tissue clearance component, and a very slow late component. For IHDA and IPPA in control hearts, early myocardial clearance kinetics were rate limited by the diffusion of catabolites. Sensitivity of the kinetics to impaired fatty acid oxidation was examination by pretreatment of animals with 2[5(4-chlorophenyl)pentyl]oxirane-2-carboxylate (POCA). Decreased fatty acid oxidation was indicated in IHDA and IPPA residue curves by a decrease in the relative size of the early clearance component. Analysis of radiolabeled species in coronary effluent and heart homogenates showed that back diffusion of IPPA was slower than that of IHDA; this discrepancy was most apparent in POCA hearts. In vitro binding assays suggested higher tissue: albumin relative affinity for IPPA than for IHDA. Thus, IPPA early clearance kinetics were more closely related to the clearance of labeled catabolite(s) and were therefore more sensitive to the oxidation rate of long chain fatty acids.     

Metabolism of methyl-branched iodo palmitic acids in cultured hepatocytes

The metabolic fate of methyl-branched iodo fatty acids was studied in primary culture of rat hepatocytes. We compared 16-iodo-2-R,S-methyl palmitic acid (2-Me), which can be beta oxidized, with 16-iodo-3-R,S-methyl palmitic acid (3-Me) which can be beta oxidized only after an initial alpha oxydation and with 16-iodo-2,2-dimethyl palmitic acid (2,2-Me2) and 16-iodo-3,3-dimethyl palmitic acid (3,3-Me2) which cannot be beta oxidized at all. The normal fate of natural fatty acids was given by comparative experiments with [1-14C] palmitic acid. Monomethyl-branched iodo fatty acids were taken up in the same range as palmitic acid but more than dimethyl-branched iodo fatty acids. After a 15-h incubation, acido-soluble products (ASP) accounted for 75% of the radioactivity taken up as 16-iodo-2-methyl palmitic acid, 50% as other methyl-branched iodo fatty acids and only 30% as palmitic acid, which indicated that all the methyl-branched iodo fatty acids underwent a strong deiodination process. Fatty acids were esterified in the following order: palmitic acid greater than 16-iodo-3-R,S-methyl palmitic acid greater than 16-iodo-2-R,S-methyl palmitic acid greater than 16-iodo-2,2-dimethyl palmitic acid greater than 16-iodo-3,3-dimethyl palmitic acid. Cultured hepatocytes, labelled for 3 h with the various fatty acids and reincubated for 12 h without fatty acid, secreted large amounts of free dimethyl-branched iodo fatty acids as compared to the monomethyl ones and palmitic acid.(ABSTRACT TRUNCATED AT 250 WORDS)     

The synthesis and evaluation of radioiodinated 14-(iodophenyl)-3-(R,S)methyltetradecanoic acid

Radiohalogenated fatty acids (FA) labelled with gamma-emitting isotopes have a potentially important application in studies of impaired myocardial perfusion and metabolism. Evaluation of straight-chain fatty acids radiolabelled in different positions on the FA chain has been reported by many groups. In this paper we extended our recent studies using the betamethyl branched-chain fatty acid. The synthesis, labelling and preliminary evaluation of 131I- and 123I-14-(iodophenyl)-3-(R,S)methyltetradecanoic acid (I-PBMTA) are reported. This radiolabel concentrates in the mouse myocardium with 16% injected dose g-1 and 11% injected dose g-1 at 15 and 30 min, respectively. The images of the canine heart postinjection indicate a high myocardial extraction of the label with activity retained over an hour. The rate of washout of the activity from the heart was very low. This analogue is a potential agent for myocardial imaging studies.     

Hepatic subcapsular steatosis in diabetic CAPD patients treated with intraperitoneal insulin. Description of a typical pattern

Purpose: To describe a specific imaging pattern of hepatic fatty change typical of diabetic patients on continuous ambulatory peritoneal dialysis (CAPD) treated with intraperitoneal (i.p.) insulin.Material and Methods: Liver ultrasound was applied in 16 CAPD patients with insulin-dependent diabetes mellitus. Presence of hepatic subcapsular steatosis and maximum thickness of the fatty layer were recorded. Liver MR examination was made of 1 patient found to have extensive subcapsular steatosis.Results: Hepatic ultrasound revealed a typical pattern of subcapsular steatosis ("coating-of-fat") in 7/8 patients treated with i.p. insulin. None (0/8) of the diabetic CAPD patients treated with subcutaneous insulin had subcapsular steatosis.Conclusion: Hepatic subcapsular steatosis is specific to CAPD patients on i.p. insulin treatment. To our knowledge this is the first report to describe imaging findings in this particular form of hepatic fatty change.     

Synthesis and initial evaluation of 17-(11)C-heptadecanoic acid for measurement of myocardial fatty acid metabolism.

Fatty acid oxidation defects are being increasingly identified as causes of abnormal heart function and sudden death in children. Children with medium-chain acyl-coenzyme A (acyl-CoA) dehydrogenase defects can metabolize fatty acids labeled in the carboxylic acid end of the compound. Accordingly, our goal was to label a long-chain fatty acid in the omega-position and evaluate its myocardial kinetics. METHODS: Heptadecanoic acid, a 17-carbon fatty acid, was labeled in the C-17 position with (11)C by the general process of coupling (11)C-methyliodide to t-butyl-15-hexadecanoate. Yield was approximately 5%-10% end-of-bombardment. Subsequently, evaluation studies were performed on isolated perfused rat hearts and in intact, anesthetized dogs. The myocardial uptake and efflux of 17-(11)C-heptadecanoic acid were compared with those of 1-(11)C-palmitate. RESULTS: With the exception of delayed efflux of tracer reflecting the temporal delay for beta-oxidation, the washout of 17-(11)C-heptadecanoic acid from the heart mirrored that of 1-(11)C-palmitate in isolated rat hearts and in intact dogs with PET. CONCLUSION: 17-(11)C-Heptadecanoic acid may be a useful tracer for the identification of defects in fatty acid metabolism in subjects with medium- and short-chain fatty acid oxidation defects.     

Whole-body MR imaging for evaluation of bone marrow cellularity in aplastic anemia

The aim of this study was to investigate the usefulness of whole-body MRI(WB-MRI) in the evaluation of cellularity in bone marrow and the distribution of fatty marrow in aplastic anemia. WB-MRI was performed on five patients with aplastic anemia who ranged in age from 62 to 70 years of age, and on four controls with malignant lymphoma who ranged in age from 59 to 67 years. Coronal images were obtained using a body coil with an FOV of 48 cm x 48 cm, and with both fast short T1 inversion recovery(STIR) and spin-echo T1-weighted(T1-WI) in three regions: (1) head to thorax, (2) abdomen to pelvis, and (3) lower extremities. The findings on WB-MRI were compared with those of histological studies of bone marrow at the sternum and the posterior iliac crest. The results were as follows: (1) there was a correlation between the cellularity of histological studies of bone marrow and signal intensity on WB-MRI; (2) WB-MRI could detect the activity of bone marrow; and (3) in a comparison of signal intensity in aplastic anemia and control subjects, there were differences of signal intensity in the central marrow.     

Metabolism of methyl-branched iodo palmitic acids in cultured hepatocytes

The metabolic fate of methyl-branched iodo fatty acids was studied in primary culture of rat hepatocytes. We compared 16-iodo-2-R,S-methyl palmitic acid (2-Me), which can be oxidized, with 16-iodo-3-R,S-methyl palmitic acid (3-Me) which can be oxidized only after an initial oxydation and with 16-iodo-2,2-dimethyl palmitic acid (2,2-Me₂) and 16-iodo-3,3-dimethyl palmitic acid (3,3-Me₂) which cannot be oxidized at all. The normal fate of natural fatty acids was given by comparative experiments with [1-¹⁴C] palmitic acid. Monomethyl-branched iodo fatty acids were taken up in the same range as palmitic acid but more than dimethyl-branched iodo fatty acids. After a 15-h incubation, acido-soluble products (ASP) accounted for 75% of the radioactivity taken up as 16-iodo-2-methyl palmitic acid, 50% as other methyl-branched iodo fatty acids and only 30% as palmitic acid, which indicated that all the methyl-branched iodo fatty acids underwent a strong deiodination process. Fatty acids were esterified in the following order: palmitic acid >16-iodo-3-R,S-methyl palmitic acid>16-iodo-2-R,S-methyl palmitic acid>16-iodo-2,2-dimethyl palmitic acid>16-iodo-3,3-dimethyl palmitic acid. Cultured hepatocytes, labelled for 3 h with the various fatty acids and reincubated for 12 h without fatty acid, secreted large amounts of free dimethylbranched iodo fatty acids as compared to the monomethyl ones and palmitic acid. Only hepatocytes prelabelled with 16-[¹²⁵I]iodo-2,2-dimethyl palmitic acid exhibited an appreciable secretion of labeled triglycerides, but at a lower rate than with [1-¹⁴C] palmitic acid. Conversely, the 16-iodo-monomethyl palmitic acids remained chiefly in hepatocyte triglycerides. Minute amounts of 16-iodo-methyl-branched-palmitic acids were found in hepatocyte or secred phospholipids as compared with palmitic acid. This metabolic fate of methyl-branched iodo palmitic acids argues against their utilization as imaging probes to monitor in vivo the synthesis and the secretion of triglycerides by the liver.