Molecular Docking Studies on Streptomycin Antileishmanial Activity

Resistance to pentavalent antimonial drugs and the lack of vaccines make it urgent to find novel therapeutic options to treat Leishmaniasis, a tropical disease caused by the Leishmania protozoan parasite. The study reported here is to investigate if Streptomycin, an aminoglycoside, and Amphotericin B, the second-line treatment drug, exhibit antileishmanial activity through a similar mechanism. By using MOE (Molecular Operating Environment), we performed molecular docking studies on these drugs binding to a range of targets including ribosome targets in Leishmania and H. sapiens. Our study shows that the two drugs do not bind to the same pockets in Leishmania targets but to the same pockets in the human ribosome, with some differences in interactions. Moreover, our 2D maps indicated that Amphotericin B binds to the A-site in the human cytoplasmic ribosome, whereas streptomycin does not.

Screening for Streptomyces Hygroscopicus Strains with High Production of Agricultural Antibiotics by Streptomycin Resistance

[Objective] The research aimed to screen Streptomyces hygroscopicus strains with high production of agricultural antibiotics. [ Method] A strain of S. hygroscopicus was screened from the soil of Hainan Island. After natural screening and consecutive ultraviolet induced mutation twice, S6-7 strain was obtained as the original strain then treated by UV irradiation and streptomycin resistance screening, and finally rescreened through shake-flask fermentation. [Result] 7 better strains were selected by primary screening from 62 single colonies which were picked out randomly. After 3 generations of consecutive cultivation on slant media and rescreening, 5 strains presented obvious forward mutation. The forward mutation rate reached 8.06%, and the largest production increasing rate came up to 25.11%. [Conclusion] By combining streptomycin resistance screening and conventional ultraviolet induced mutation, both the antibiotic-producing capacity and forward mutation screening efficiency of the original strain were greatly enhanced.

An Improved Adaptive Multi-way Principal Component Analysis for Monitoring Streptomycin Fermentation Process

Multi-way principal component analysis (MPCA) had been successfully applied to monitoring the batch and semi-batch process in most chemical industry. An improved MPCA approach, step-by-step adaptive MPCA (SAMPCA), using the process variable trajectories to monitoring the batch process is presented in this paper. It does not need to estimate or fill in the unknown part of the process variable trajectory deviation from the current time until the end. The approach is based on a MPCA method that processes the data in a sequential and adaptive manner. The adaptive rate is easily controlled through a forgetting factor that controls the weight of past data in a summation. This algorithm is used to evaluate the industrial streptomycin fermentation process data and is compared with the traditional MPCA. The results show that the method is more advantageous than MPCA, especially when monitoring multi-stage batch process where the latent vector structure can change at several points during the batch.

Field Efficiency Trial of 72% Streptomycin against Konjac Bacterial Soft Rot

72% Streptomycin soluble powder was used to control konjac bacterial soft rot in the study. The control efficiency and yield of different treatments were investigated,and the benefit was analyzed. The control scheme against konjac bacterial soft rot was as follows: spraying 72% atreptomycinon twice on rotation fields after all the seedlings were strong and uniform,or irrigating roots with 72% atreptomycinon once and spraying twice on continuous cropping fields.

Streptomycin-Induced Steven-Johnson Syndrome in a HIV Sero-Positive Patient with Tuberculosis: A Case Report

Severe cutaneous hypersensitivity reactions to anti-tuberculosis medication are rare and have been attributed mainly to thiacetazone. A case of streptomycin-induced Steven-Johnson Syndrome in a patient with TB-HIV co-infection which ended in death is reported.

Fabrication of anti-fouling polyamide nanofiltration membrane by incorporating streptomycin as a novel co-monomer

Polyamide(PA)thin-film composite(TFC)na nofiltration(NF)membrane has extremely broad application prospects in separation of monovalent/diva lent inorganic salts mixed solutio n.However,membrane fouling is the main obstacle to the application of PA,TFC and NF membrane.Streptomycin(SM)is a hydrophilic antibiotic containing a large number of hydroxyl and amino groups.In this work,the NF membrane was prepared via interfacial polymerization(IP)between trimesoyl chloride(TMC)in the organic phase and SM/piperazine(PIP)mixture in the aqueous phase.The NF membrane structure and performance were characterized in detail.The results showed that SM successfully participated in the IP.The negative charge and hydrophilicity of membrane surface were improved.The prepared membrane exhibited good anti-adhesion and anti-bacterial performance,Additionally,when the SM concentration was 2%,the prepared membrane exhibited the optimal permselectivity.The water permeance was 89.4L·m^(-2)·h^(-1)·MPa^(-1).The rejection of NaCl and Na_(2)SO_(4) were 17,17%and 97.84%,respectively.The NaCl/Na_(3)SO_(4) separation factor of the SM2-PIP/TMC membrane in 1000 mg·L^(-1) NaCl and 1000 mg·L^(-1)Na_(2)SO_(4) mixed solution was 40,which was 3.3 times that of PIP/TMC membrane.It indicated that SM2-PIP/TMC demonstrated excellent monovalent/divalent salts separation performance.This work provided an easy and effective approach to preparing anti-fouling NF membrane while possessing superior monovalent/divalent salts separation performance.

Pharmacokinetic Disposition of Streptomycin Sulfate in Japanese Eel (<i>Anguilla japonica</i>) after Oral and Intramuscular Administrations

Pharmacokinetics and residue elimination of streptomycin sulfate (STR) are important in the determination of optimal dosage regimens and in establishing safe withdrawal periods in farmed fishes. The pharmacokinetics of STR was studied after a single dose (50 mg/kg) of intramuscular (i.m.) or oral gavage (p.o.) administration to Japanese eel (Anguilla japonica) in freshwater at 25°C. Eight fish per sampling point were examined after treatment. Plasma and muscle were collected and analyzed by high-performance liquid chromatography (HPLC) method with 0.05 μg/ml detection limit. The data of pharmacokinetics conformed to the two-compartment open model for intramuscular and one-compartment open model for oral administrations. After intramuscular administration, the elimination half-life (t1/2β) was calculated to be 11.346 h, the maximum plasma concentration (Cmax) to be 29.524 μg/ml, the time to peak plasma streptomycin concentration (Tmax) to be 0.218 h, and the area under the plasma concentration-time curve (AUC) to be 90.206 μg/ml?h. Following p.o. administration, the corresponding estimates were 13.239 h, 0.346 μg/ml, 11.960 h, and 12.356 μg/ml?h. After intramuscular administration, a therapeutic concentration of the drug was maintained for 12 hours in the plasma, however, a therapeutic level could not be achieved after oral administration, and the results suggest that the drug can be used clinically by intramuscular administration against streptomycin susceptible systemic infections in Japanese eel.

The Use of the PCR-Based Dot-Blot Hybridization Assay to Detect Resistance Markers to Rifampicin and Streptomycin in Mycobacterium tuberculosis Isolates from the SW Region of Cameroon

Drug sensitivity testing to establish resistance to TB drugs takes many months to arrive at. Public health physicians have difficulties with such an approach due to long wait periods and cannot use it to establish community wide prevalence as a way to understand where resistance may be emerging faster and to limit its spread. The objective of this study was to use the dot-blot hybridization technique in the detection of resistance to rifamycin (RIF) and streptomycin (SM) in South- Western Cameroon and to compare the technique with the routine culture and drug susceptibility testing for detecting resistance in a resource poor country, Cameroon. A hospital-based study was conducted at the Regional hospitals of Buea and Limbe and Tiko Central Clinic. Tuberculosis (TB) patients aged 15 to 50 (mean age: 30.50 ± 8.33 standard deviation) were recruited for the study between December 2006 and April 2007. Cultures from 59 patients were tested for rifampicin and streptomycin sensitivity by the modified proportion method and mutational analysis for rpoB codon 516 and rrs codon 513 was performed by the dot-blot hybridization technique. Of the 59 sputum samples collected (36 were males and 23 were females) came from Buea 19 (32.2%), Limbe 20 (33.9%) and Tiko 20 (33.9%) towns respectively. Amplification for the gene showed that there was (59) 100% amplification with primers used for rpoB genes and 43 (72.9%) amplification with primers used for the rrs gene. Mutational analysis demonstrated that resistance to RIF was common in females (52.1%) than males (41.7%) while 6% of the samples were indeterminate. 12 (20.3%) samples showed phenotypic and genotypic resistance to RIF compared to 34 samples (58.1%) for SM. Phenotypic resistance and genotypic susceptibility were found in 5 (8.5%) RIF and 3 (4.7%) SM compared to phenotypic susceptibility and genotypic resistance that were found in 2 (3.5%) RIF and 3(4.7%) SM. Double mutation on rpoB and rrs genes occurred in 8 (13.6%) DNA samples. Resistance to RIF and SM due to mutations on the rpoB and rrs genes respectively in the SW region was found to be high and comparable to the drug susceptibility testing by 92%, (95% CI: 75.7 - 99.1). The Dot-blot technique will be useful in rapidly assessing the effectiveness of national TB control programs in limiting the spread of resistance strains in Cameroon.

A comparative study of adsorption behavior of rifampicin,streptomycin,and ibuprofen contaminants from aqueous solutions onto chitosan:Dynamic interactions,kinetics,diffusions,and mechanisms

Adsorptive removal and dynamic interaction of three different pharmaceutical pollutants,namely rifampicin(RIF),streptomycin(STM),and ibuprofen(IBU)onto chitosan were systematically investigated using a batch adsorption technique at different processing parameters.In this study,chitosan was derived from mud-crab shells,as an innovative way to use the waste from marine foods as adsorbents.The kinetics,intraparticle diffusion,mechanism,and thermodynamics of the adsorption were systematically evaluated and analyzed using kinetic models,Boyd mass transfer and WebereMorris intraparticle diffusion models,Langmuir,Freundlich,DubinineRadushkevich,and Temkin isotherm models,and the Gibbs equation.The adsorption isotherm of the larger molecules,RIF and STM,could be explained by the Langmuir isotherm model,in contrast,that of IBU,which is a much smaller molecule,followed the Freundlich isotherm model.The maximum adsorption capacity of RIF,STM,and IBU on chitosan was estimated to be 66.91 mg g^(-1),11.00 mg g^(-1),and 24.21 mg g^(-1),respectively,which are higher compared to those on a variety of agricultural wastes,suggesting that this biopolymer is a potential practical and economical adsorbent to remove the pharmaceutical compounds from wastewater.The adsorption mechanism of the pharmaceutical compounds on chitosan is proposed based on the vibrational spectroscopic analyses,XRD patterns,and DSC thermograms of the biopolymer before and after adsorption process.

蜂蜜中链霉素仿生印迹电化学传感检测方法

动物源食品中链霉素残留危害严重,建立高性能分析方法是确保食品安全和人类健康的必要手段。仿生印迹电化学传感检测方法具有高效、特异和灵敏等优点,已成为食品安全检测技术研究的重要领域。该研究以链霉素为模板分子,氧化石墨烯和壳聚糖为增敏材料,3-氨基苯基硼酸和邻苯二胺为复合功能单体,采用电聚合法构建了仿生印迹聚合物传感界面,建立了蜂蜜中链霉素的仿生印迹电化学传感检测方法。通过扫描电镜对印迹传感界面进行了表征,采用循环伏安法、差分脉冲伏安法和电化学交流阻抗法对仿生印迹传感器的电化学性能进行表征。在最佳反应条件下,该传感器的检测限为2.59×10^(-12) mol/L,线性范围为1.0×10^(-10)~1.0×10^(-6) mol/L,洋槐蜜、枣花蜜和桂花蜜样品的加标回收率分别为94.78%~106.24%、93.65%~103.81%和97.19%~106.18%,相对标准偏差≤4.28%。试验结果表明,该方法具有良好的重复性、稳定性和重现性,能够满足蜂蜜中链霉素残留分析的需要。相关研究为复杂基质中痕量靶标的高特异性和超灵敏分析提供了技术支撑,对于蜂蜜中链霉素的快速筛查和安全监测具有重要意义。

高分辨率熔解曲线快速检测结核分枝杆菌对链霉素耐药情况的研究

探讨高分辨率熔解曲线(HRM)技术检测结核分枝杆菌对链霉素耐药性的可行性。用传统药物敏感性试验进行结核分枝杆菌链霉素耐药性检测;以Rpsl和rrs的耐药决定区为靶点设计引物进行HRM分析,判断菌株是否对链霉素耐药;以药敏结果为标准,应用SPSS17.0分析两种检测结果之间的符合率;Kappa检验分析两种结果的一致性。药敏结果显示,84株菌株中有20株对链霉素耐药,64株为敏感株;HRM检测结果显示,24株菌株对链霉素耐药,60株为敏感株;以药敏结果为参照,HRM检测结核分枝杆菌对链霉素耐药性的敏感性为75%,特异性为85.9%,经Kappa检验显示,两种方法检测结果具有中度一致性。本研究结果表明HRM可快速检测结核分枝杆菌对链霉素的耐药性,具有较好的灵敏度,在耐药结核病的早期辅助诊断方面具有一定的应用价值。

江西省耐多药结核分枝杆菌链霉素基因突变特征

目的了解江西省耐多药结核分枝杆菌中链霉素耐药的分子特征,探究北京基因型结核与链霉素耐药基因(rpsL、rrs和gidB)突变及链霉素耐药表型之间的关系。方法收集南昌大学第一附属医院高新医院及江西省胸科医院2021年1-12月分离的非重复耐多药结核菌106例,检测其耐药表型、是否为北京基因型及与链霉素耐药基因rpsL、rrs和gidB突变的关系。χ^(2)检验rpsL、rrs和gidB基因突变与北京基因型及表型关系。结果106例耐多药结核菌中链霉素耐药76例,其中58例rpsL 43A>G突变,8例88A>G突变,5例rrs突变,3例gidB突变。任何rpsL、rrs和gidB基因突变与表型耐药的符合率为89.6%,特异度及敏感度分别为86.7%和90.8%。北京型结核菌分离率为88.7%,其耐药基因突变主要集中于rpsL和rrs,非北京型菌耐药突变则主要集中于gidB;北京型菌更容易发生基因突变(P=0.013),但表型耐药无差异。结论rpsL、rrs和gidB基因突变与表型耐药符合率较好,可采用分子生物学直接检测耐药基因预判菌株耐药性;结核菌型与链霉素耐药特征具有紧密联系。

链霉素分子印迹电化学传感器的制备及应用——推荐一个分析化学综合实验

设计了一个将分子印迹技术引入到本科教学的探究性仪器分析综合实验。本实验首先通过电聚合法制备链霉素分子印迹电化学传感器(STR-MIM/GCE),然后以循环伏安法和扫描电镜对传感器进行表征,再以铁氰化钾为探针,采用差示脉冲伏安法建立传感器测定链霉素的电化学分析方法,并以牛奶为实际样品进行检测。本实验涉及电极表面的修饰与表征、电化学分析方法的建立与应用,有助于拓宽学生思维,激发科研兴趣,同时实验所用试剂价廉易得,不涉及大型仪器设备,实验时长合理,适合本科教学。

Monoclonal antibody-based ELISA and colloidal gold-based immunochromatographic assay for streptomycin residue detection in milk and swine urine

A protein conjugate of streptomycin （streptomycin-bovine serum albumin （BSA） conjugate） was prepared and used as immunogen to produce monoclonal antibodies （MAb）. One hybridoma secreting anti-streptomycin MAb was obtained and then used to produce MAb. The MAb named 13H5 showed the 50% maximal inhibitory concentra- tion （IC50） value of 4.65 ng/ml and the IC20value of 0.21 ng/ml in phosphate buffered saline （PBS）. At optimum con- ditions, an indirect competitive enzyme-linked immunosorbent assay （ELISA） and a colloidal gold-based immuno- chromatographic assay （CGIA） were developed and applied to detect streptomycin residues in milk and swine urine samples. The developed ELISA showed that the minimum detection limit was 2.0 and 1.9 ng/ml for milk and swine urine samples, respectively, without obvious cross-reactivity to other tested antibiotics except dihydrostreptomycin which gave a 118.32% cross reaction value. Milk and swine urine samples spiked with streptomycin at 10, 50, 100 and 200 ng/rnl were analyzed by the established ELISA. The mean recovery of streptomycin was from 81.9% to 105.5% and from 84.3% to 92.2% for milk and swine urine, respectively. The optimized CGIA showed that the minimum de- tection limit was 20.0 ng/ml for milk and swine urine samples. The results of spiked analysis and specific analysis demonstrate that the CGIA could be applicable for screening milk and swine urine samples for the presence of streptomycin residues on-site. The established ELISA and CGIA allow the rapid, low-cost, and sensitive determination of streptomycin residues in food samples.

An Aptamer-based Colorimetric Sensor for Streptomycin and Its Application in Food Inspection

An aptamer-based colorimetric biosensor was developed, which could be used to detect residual strepto- mycin from food quickly and cost-effectively. The ssDNA aptamer target for streptomycin was obtained using sys- temic evolution of ligands by exponential enrichment through affinity chromatography. A total of 19 candidates were obtained after 10 rounds of selection and were grouped into 3 families according to their similarity of sequence and structure. Among them, aptamer A15 showed the highest affinity for streptomycin tested by fluorescence intensity analysis with a dissociation constant of 6.07 nmol/L. Aptamer A15 also exhibited a higher streptomycin specificity with the lowest detectable limit of 25 nmol/L according to the value of A620/A520 ratio with AuNP-based colorimetric assay. The method was specific and sensitive for the detection of streptomycin from simply-treated milk and honey at 100 and 125 nmol/L, respectively, and is a promising approach to monitor antibiotics or other small molecules ana- logues in food inspection.

Bi/BiVO_(4)/NiFe-LDH heterostructures with enhanced photoelectrochemical performance for streptomycin detection

Streptomycin(STR)plays an essential role in bacterial infection treatments.Selectivity and sensitivity of photoelectrochemical(PEC)sensors are the two most important parameters,which can be measured using the photosensitivity of its active material.We prepared a novel PEC sensor to detect STR using Bi/BiVO4/LDH(layered double hydroxides)heterostructures as an active material,which is photoactive in the visible light wavelength range.The simultaneous presence of LDH and Bi/BiVO4 enhanced the material photocurrent response,which was linear to the STR concentrations in the 0.01–500 nmol/L range.The STR detection limit by this sensor was 0.0042 nmol/L.Our novel PEC-based sensing strategy includes using an ultra-sensitive and highly selective sensor for STR detection.Additionally,the two-pot synthesis of Bi/BiVO4/LDH developed in this work is environmentally friendly.

链霉素驱动微藻叶绿素荧光动力学的响应研究

为了探究微藻对链霉素的敏感性,通过叶绿素荧光动力学(OJIP)分析蓝藻-拟柱孢藻(Raphidiopsis raciborskii)和绿藻-四尾栅藻(Scenedesmus quadricauda)对链霉素的响应.研究结果表明,链霉素对拟柱孢藻和四尾栅藻的反应中心耗散的能量(DI0/RC)、单位光面积吸收的能量(ABS/CS0)和单位反应中心吸收的能量(ABS/RC)均有显著的促进作用,对拟柱孢藻单位反应中心捕获的用于还原QA的能量(TR0/RC)起抑制作用,且链霉素能够明显降低拟柱孢藻的光合驱动力.利用质量浓度为0.05~1.0 mg/L和1.0~20.0 mg/L的链霉素分别培养拟柱孢藻和四尾栅藻,其比生长率分别是对照组(0.00 mg/L)的0.74~0.25和1.19~0.51倍.拟柱孢藻丙二醛含量和超氧化物歧化酶活性明显随链霉素质量浓度的升高而降低,过氧化氢酶活性随链霉素质量浓度的升高而增加.四尾栅藻的过氧化氢酶活性、丙二醛含量和超氧化物歧化酶活性对链霉素质量浓度响应敏感度低.因此,本研究认为蓝藻对链霉素的敏感性比绿藻显著,主要原因是拟柱孢藻和四尾栅藻的能量分布存在显著差异.

探针熔解曲线在耐药结核病快速筛查中的临床应用研究

目的研究探针熔解曲线在耐药结核病快速筛查中的临床应用价值。方法选取2020年1月—2021年3月镇江市第三人民医院收治的378例肺结核患者为研究对象,依次完成传统罗氏固体药物敏感性检测(比例法)、探针熔解曲线技术检测常用的6种药物耐药结果,包含利福平、异烟肼、乙胺丁醇、链霉素、氧氟沙星、阿米卡星,和比例法进行对比,计算探针熔解曲线技术检测6种药物的敏感度、特异度、阳性预测值、阴性预测值、符合率与约登指数。结果与比例法作比较,熔解曲线技术检测利福平耐药性的敏感度、特异度、阳性预测值、阴性预测值、符合率、约登指数分别为91.70%、98.10%、61.10%、99.70%、97.90%、0.898;异烟肼是87.90%、94.20%、59.20%、98.80%、93.65%、0.821;乙胺丁醇是87.50%、97.03%、38.89%、99.72%、96.83%、0.845;链霉素是91.30%、98.19%、87.50%、98.79%、97.35%、0.895;氧氟沙星是94.74%、98.89%、81.82%、99.72%、98.68%、0.936;阿米卡星是80.00%、99.46%、66.67%、99.73%、99.21%、0.795。结论探针熔解曲线在耐药结核病快速筛查中应用,具有较高敏感度及特异度,有利于临床早期识别耐药现象。

Streptomycin inhibits electrophysiological changes induced by stretching of chronically infarcted rat hearts

Objective： To investigate stretch-induced electrophysiological changes in chronically infarcted hearts and the effect of streptomycin （SM） on these changes in vivo. Methods： Sixty Wistar rats were divided randomly into four groups： a control group （n=15）, an SM group （n=15）, a myocardial infarction （MI） group （n=15）, and an MI＋SM group （n=15）. Chronic MI was obtained by ligating the left anterior descending branch （LAD） of rat hearts for eight weeks. The in vivo blockade of stretch-activated ion channels （SACs） was achieved by intramuscular injection of SM （180 mg/（kg·d）） for seven days after operation. The hearts were stretched for 5 s by occlusion of the aortic arch. Suction electrodes were placed on the anterior wall of left ventricle to record the monophasic action potential （MAP）. The effect of stretching was examined by assessing the 90% monophasic action potential duration （MAPD90）, premature ventricular beats （PVBs）, and ventricular tachycardia （VT）. Results： The MAPD90 decreased during stretching in both the control （from （50.27±5.61） ms to （46.27±4.51） ms, P〈0.05） and MI groups （from （65.47±6.38） ms to （57.47±5.76 ms）, P〈0.01 ）. SM inhibited the decrease in MAPD90 during inflation （（46.27±4.51） ms vs. （49.53±3.52） ms, P〈0.05 in normal hearts; （57.47±5.76） ms vs. （61.87±5.33） ms, P〈0.05 in MI hearts）. The occurrence of PVBs and VT in the MI group increased compared with that in the control group （PVB： 7.93±1.66 vs. 1.80±0.86, P〈0.01; VT： 7 vs. 1, P〈0.05）. SM decreased the occurrence of PVBs in both normal and MI hearts （0.93±0.59 vs. 1.80±0.86 in normal hearts, P〈0.05; 5.40±1.18 vs. 7.93±1.66 in MI hearts, P〈0.01）. Conclusions： Stretch-induced MAPD90 changes and arrhythmias were observed in chronically infarcted myocardium. The use of SM in vivo decreased the incidence of PVBs but not of VT. This suggests that SACs may be involved in mechanoelectric feedback （MEF）, but that there might be other mechanisms involved in causing VT in chronic MI.

DIFFERENT EFFECTS OF STREPTOMYCIN DEPENDENT MUTATION ON THE EXPRESSION OF λV AND λQ GENES IN Escherichia coli~*

Ⅰ. INTRODUCTIONAll protein syntheses are carried out on ribosomes, therefore the ribosomes are extremely important to biological activities. So far the composition of the ribosomal structure including three kinds of rRNAs and over filly ribosomal proteins has been elucidated in detail. But the exact functions of the ribosomal proteins remain almost totally unknown.