In silico epitope identification of unique multidrug resistance proteins from Salmonella Typhi for vaccine development

Typhoid fever is a multisystemic illness caused by Salmonella enterica serovars Typhi and is resistant to most antibiotics and drugs. The resistance is conferred through multidrug resistance (MDR) proteins, which efflux most antibiotics and other drugs. We predicted potential candidate B-cell and T-cell epitopes using bio- and immune-informatics tools in the 11 MDR proteins - EmrA, EmrB, EmrD, MdtA, MdtB, MdtC, MdtG, MdtH, MdtK, MdtL and TolC. The antigenic potential of the MDR proteins was calculated using VaxiJen server. The B-cell and T-cell epitopes of the MDR proteins were predicted using BCPred and ProPredI and ProPred respectively. The binding affinities of the predicted T-cell epitopes were estimated using T-epitope designer and MHCPred tools. 10, 7, 5, 12, 14, 21, 26, 3, 3 and 3 B-cell epitopes were identified in EmrA, EmrB, EmrD, TolC, MdtA, MdtB, MdtC, MdtG, MdtH and MdtL respectively. We predicted 9 T-cell epitopes - YVSRRAVQP (EmrA), FGVANAISI (EmrB), MVNSQVKQA and YQGGMVNSQ (TolC), WDRTNSHKL (MdtA), FLRNIPTAI (MdtB), YVEQLGVTG (MdtG), VKWMYAIEA (MdtH) and LAHTNTVTL (MdtL) capable of eliciting both humoral and adaptive immune responses. These T-cell epitopes specifically bind to HLA alleles - DRB1*0101 and DRB1*0401. This is the first report of epitope prediction in the MDR proteins of S. Typhi. Taken together, these results indicate the MDR proteins – EmrA, MdtA and TolC are the most suitable vaccine candidates for S. Typhi. The findings of our study on the MDR proteins prove to be useful in the development of peptide-based vaccine for the prevention and/or treatment of typhoid fever.     

Exploration of the site-specific nature and generalizability of a trimethylammonium salt modification on vancomycin: A-ring derivatives

Vancomycin analogues bearing an A-ring trimethylammonium salt modification were synthesized and their antimicrobial activity against vancomycin-resistant Enterococci (VRE) was evaluated. The modification increased antimicrobial potency and provided the capability to induce bacteria cell membrane permeabilization, but both properties were weaker than that found with our earlier reported similar C-terminus modification. The results provide further insights on the additive effect and generalizability of the structural and site-specific nature of a peripheral quaternary trimethylammonium salt modification of vancomycin.     

荧光光度法测定抗生素氧氟沙星

本文报道了采用荧光分光光度法测定喹喏酮类抗生素氧氟沙星,该方法有较高的灵敏度,在氧氟沙星浓度为０．５００ｐｐｍ至２５．０ｐｐｍ间,荧光强度与浓度有良好的线性关系,线性相关系数为０．９９９９,回收率为９９．０％测定结果与紫外分光光度法测量结构无显著性差异。     

氨基糖苷类抗生素分析方法的研究进展

对近20年来氨基糖苷类抗生素分析方法的进展进行了评述,其中包括微生物法、分光光度法、发光分析法、免疫分析法、色谱分析法、电化学分析法、共振瑞利散射法以及其他一些分析方法。引用文献79篇。     

大网格吸附剂提取新抗生素M－90的研究

本文研究用大网格吸附剂从发酵液中提取抗生素Ｍ－９０的吸附与解吸过程。包括：吸附剂、解吸剂的选择，加盐对吸附情况的影响，以及吸附条件和解吸条件的筛选等。结果表明，ＣＡＤ－４５为最佳吸附剂，吸附最佳ｐＨ为８．０；流速选择０．５ｍｌ／分；加３％ＮａＣｌ对吸附有利，最佳解吸剂为ｐＨ６．０９５％乙醇。在本实验条件下，当吸附液中Ｍ－９０浓度为２３０Ｕ／ｍｌ左右时，ＣＡＤ－４５对Ｍ－９０的吸附量达２．２２万Ｕ／ｍｌ吸附剂，吸附率为９６．８２％，解吸率为９３．７８％，收率为９０．８０％。     

抗菌素药物使用调查分析

随机抽取了浙江省台州市黄岩妇幼保健院３００张儿科门诊处方，对使用抗菌素药物的情况进行了调查分析，结果发现，存在抗菌素选择、联合使用或配伍不当、用量过多、输注方法不妥及盲目预防等情况，需引起注意。     

Contribution to the alkaline degradation of cefepime

Deviations of the value of the rate constant for borate anions of the first step in the degradation of the antibiotic cefepime from Bronsted relation and deviations from i=f(pH) plots in voltammetric reductions of the oximino group led to investigation of the kinetics of degradation of cefepime in ammonia, borate, CHES and glycine buffers pH 9.3 using UV–visible spectra. Presence of at least two consecutive processes was detected and an interaction of cefepime with glycine has been proved. Identification of intermediates is under investigation.     

Identification of novel vaccine candidates against carbapenem resistant Klebsiella pneumoniae: A systematic reverse proteomic approach

Klebsiella pneumoniae is declared as antibiotic resistant by WHO, with the critical urgency of developing novel antimicrobial therapeutics as drug resistance is the second most dangerous threat after terrorism. Besides many attempts still, there is no effective vaccine available against K. pneumoniae. By utilizing all the available proteomic data we prioritized the novel proteins ideal for vaccine development using bioinformatics tools and techniques. Among the huge data, eight proteins passed all the barriers and were considered ideal candidates for vaccine development. These include: copper silver efflux system outer membrane protein (CusC), outer membrane porin protein (OmpN), Fe⁺⁺ enterobactin transporter substrate binding protein (fepB), zinc transporter substrate binding protein (ZnuA), ribonuclease HI, tellurite resistant methyltransferase (the B), and two uncharacterized hypothetical proteins (WP_002918223 and WP_002892366). These proteins were also subjected to epitope analysis and were found best for developing subunit vaccine against K. pneumoniae. The study shows that the potential vaccine targets are sufficiently efficient being virulent, of outer membranous origin and can be proposed for the DNA third-generation vaccines development that would help to cope up infections caused by multidrug-resistant K. pneumoniae.     

Mcm-41 Materials as Catalysts for the Synthesis of Alkyl Fructosides

ABSTRACT

Alkylation of saccharides combines the essential characteristics of two major renewable classes, viz. triglycerides and carbohydrates, while leading to biofriendly surfactants and emulsifiers. The development of alkylated derivatives of fructose has lagged because no efficient synthesis was available. We have found that mesoporous materials of the MCM-41 type are active and selective catalysts for the alkylation of fructose. Quantitative yields were obtained in the reaction of fructose with lower alcohols, up to C4. For long chain alcohols yields were moderate but the alkyl fructopyranosides could be easily purified. The other isomers could be isolated by chromatography.     

Cu(II) and Zn(II) complexes with a fluoroquinolone antibiotic: Spectroscopic and X-ray absorption characterization

The synthesis of two complexes with the antibiotic flumequine, [Cu(Flumequine)₂(OH₂)₂] (1) and [Zn(Flumequine)₂(OH₂)₂]·H₂O (2) is reported. Their molecular structure was elucidated by combining various spectroscopic techniques. The EPR parameters combined with XAS data underline a tetragonal distorted octahedral geometry for the two complexes. The coordination occurs through the carbonyl and carboxylate oxygen atoms in the equatorial plane. The coordination sphere is completed by two water molecules in axial position.