武汉地区结核分枝杆菌链霉素耐药分离株rpsL基因分子特征研究

探讨武汉地区结核分枝杆菌链霉素（SM）耐药临床分离株rpsL基因分子特征。收集71株临床分离株,采用刃天青法测定临床分离株对SM的最低抑菌浓度（MIC）,同时用直接测序法分析rpsL基因的突变情况;用RD105基因缺失检测法鉴定71株临床分离株中＂北京基因型＂菌株。结果显示20株SM敏感株rpsL基因未发现突变（MICs〈0.25 mg/L）;51株SM耐药株中,35株（68.6%）检测到rpsL基因突变,主要发生在第43位和88位密码子,MIC≤1 mg/L的SM耐药株（低水平耐药株）总突变率低于MIC≥2mg/L（高水平耐药株）;北京基因型与耐药株的相关性不大。研究表明SM耐药菌株rpsL基因突变类型存在地域差异;rpsL突变与SM高水平耐药的相关性在本研究中关联度不大;＂北京基因型＂菌株在武汉地区呈流行趋势。     

结核分枝杆菌链霉素耐药临床分离株 rrs基因突变与其耐药水平相关性研究

研究武汉地区耐链霉素（ SM）结核分枝杆菌的耐药分子机制,进一步研究阐明rrs基因突变与结核分枝杆菌耐链霉素的关系;同时探究武汉地区结核分枝杆菌“北京基因型”菌株的流行趋势,为进一步研究武汉地区耐链霉素菌株rrs基因突变与“北京基因型”的相关性奠定基础。84株结核分枝杆菌中,44株对链霉素耐药,20株耐其它药物,20株对链霉素敏感,采用PCR直接测序法分析链霉素菌株rrs基因突变情况;采用RD105缺失法鉴定84株临床分离菌株中“北京基因型”菌株。结果显示44株SM耐药菌株中,16（36．4％）株检测到rrs基因突变,其中9株1401位点A→G,6株514位点A→C突变,1株1487位点G→A突变;20株耐其它药菌株中1401位点A→G和514位点A→C突变各1株,20株敏感菌株中发现1株1029位点C→T点突变;84株临床分离菌株中有77（91．8％）株“北京基因型”菌株,7株非“北京基因型”菌株。研究表明链霉素耐药菌株rrs基因主要突变位点在514和1401位点,武汉地区“北京基因型”菌株为当地流行的结核分枝杆菌,且SM耐药菌株中突变菌株93．8％（15/16）为“北京基因型”,“北京基因型”菌株研究及其鉴定是有其科学价值的,值得我们重视。     

DNA Antenna Tile‐Associated Deoxyribozyme Sensor with Improved Sensitivity

Some natural enzymes increase the rate of diffusion‐limited reactions by facilitating substrate flow to their active sites. Inspired by this natural phenomenon, we developed a strategy for efficient substrate delivery to a deoxyribozyme (DZ) catalytic sensor. This resulted in a three‐ to fourfold increase in sensitivity and up to a ninefold improvement in the detection limit. The reported strategy can be used to enhance catalytic efficiency of diffusion‐limited enzymes and to improve sensitivity of enzyme‐based biosensors.     

疏水性微生物对细粒煤的絮凝试验研究

在对疏水性微生物草分枝杆菌的生物学特性研究基础上,利用草分枝杆菌对煤炭进行了絮凝试验。并与传统的无机电解质凝聚剂和有机高分子絮凝剂所进行的对比试验。结果表明,草分枝杆菌对细粒煤具有良好的絮凝作用效果。由于该菌还具有无毒无害以及可生物降解等许多环境友好的特点。因此,将为绿色高效煤炭絮凝剂的研究和开发探索了一条有极大发展前景的新途径。     

Molecular Epidemiological Study of Pyrazinamide-Resistance in Clinical Isolates of Mycobacterium tuberculosis from South India

Pyrazinamide (PZA) has been in use for almost 50 years as a first-line drug for short-course chemotherapy against Mycobacterium tuberculosis. In this study, PCR mediated automated DNA sequencing is used to check the prevalence of PZA resistance among treatment failure cases of pulmonary tuberculosis. Out of 50 clinical isolates examined, 39 had mutations in the pncA gene that encodes Pyrazinamidase, an enzyme required to activate PZA. Of these, 31 (79.5%) were localized to three regions of pncA. We found two isolates with hitherto unreported mutation at amino acid 26 (Ala→Gly) of pncA.     

PYRENE ENCAPSULATED ALGINATE BEAD TYPE FOR SUSTAINED RELEASE IN BIODEGRADATION: PREPARATION AND CHARACTERISTICS

A novel method for preparation of pyrene encapsulated alginate beads for controlled release delivery of pyrene is reported in this study. Five different bead types that varied on the organic phase for pyrene delivery, presence or absence of polyvinyl alcohol (PVA) and boric acid treatment were prepared. Based on the pyrene release profile, silicone oil encapsulated in PVA-alginate bead was selected where encapsulation efficiency was more than 99% without any solvent leakage. Silicone oil encapsulation was further confirmed in microscopy observations. Pyrene release behavior from the beads was explained by a diffusion controlled first order release (R² > 0.96). Reusability of this bead was demonstrated, where pyrene was loaded from an external medium in a non-destructive way. Application of the system was finally established in a biodegradation study using Mycobacterium frederiksbergense, where simultaneous release and removal of pyrene along with appearance of pyrene metabolites was observed.     

草分枝杆菌选择性絮凝脱除煤中黄铁矿硫的研究

对疏水性微生物草分枝杆菌(M．phlei)进行培养，并结合红外光谱分析，研究了草分枝杆菌(M．phlei)的生物学特性及对煤的絮凝作用．试验结果表明，草分枝杆菌(M．phlei)可选择性地吸附作用于煤表面，在实现对煤絮凝的同时，能较有效地脱除煤中的黄铁矿硫．     

Effect of a Water Soluble Fraction Derived from Mycobacterium phlei on the Surface Characteristics and Flotation of Apatite and Dolomite

Abstract

When Mycobacterium phlei is subjected to sonication, a solid and a water soluble fraction are obtained. The water soluble material is highly surface-active and adsorbs onto both dolomite and apatite. In both cases the mineral becomes more hydrophobic with the effect being greater on dolomite than on apatite. The change in surface characteristics of the minerals was monitored by contact angle, zeta potential and micro flotation experimentation. The data obtained were compared to results obtained when whole cells of M.phlei were used in place of the soluble fraction. Implications on the effect of the addition of both M.phlei and its soluble fraction on the flotation separation of the two minerals are discussed.     

草分枝杆菌在矿物絮凝浮选的应用探讨

介绍了草分枝杆菌的结构和性能 ,综述了草分枝杆菌的应用研究现状 ,探索了草分枝杆菌在环保净化、固废利用等领域的可能性 ,为草分枝杆菌的应用研究指明了方向。