Study of components of standard samples of polyene macrolide antibiotics by the methods of high performance liquid chromatography and SIEAP mass spectrometry]

The component composition of reference samples of polyenic macrolide antibiotics such as nystatin, mycoheptin, amphotericin B and levorin was studied by HPLC and chromatographic mass spectrometry in comparison to the WHO standards. It was shown that the samples were close by their component composition to the analogous samples of the WHO standards.     

Interaction of neomycin with other antibiotics on selected bacterial strains

Antimicrobial combinations are used most frequently to provide broad-spectrum empirical coverage in the treatment of bacterial infections. However, combination of two antibiotics may not influence their activity, may lead to synergy or antagonism in the activity. Neomycin may be combined with one of the following antibiotics: ampicillin, procaine penicillin, gramicidin, bacitracin, polymyxin B, lincomycin, oxytetracycline, and erythromycin in some human and veterinary multiantibiotic drugs distributed in Poland. The checkerboard method has been one of the traditional assays for the measurement of antibiotic interactions. The aim of this study was to analyse the activity interaction of neomycin with second antibiotic in multiantibiotic drugs distributed in Poland on standards and clinical bacterial strains. Checkerboard results for all strains demonstrated synergism for 2.5% of combinations, only for standards strains. In one case Salmonella Enteritidis, in combination of neomycin with bacitracin, inhibition effect was observed. Additive effects were predominant--49%. In 18% neutral effects were shown, but in 26% of combinations FIC indexes were not possible to calculate, because of the resistance of clinical strains to the highest concentration of at least one antibiotic. In combination of aminoglycoside (neomycin) with beta-lactams antibiotics (ampicillin, procaine penicillin) in vitro, no synergy was observed for all examined strains. The best results were achieved for combinations of neomycin with peptide antibiotics (polymyxin, gramicidin and bacitracin)--5 for all 6 synergy effect observed.     

Species-specific sensitivity of coagulase-negative Staphylococci to single antibiotics and their combinations

The activity of beta-lactam antibiotics (oxacillin, cloxacillin, cephalotin), vancomycin, gentamicin and rifampicin applied in vitro individually and in combination against 37 nosocomial methicillin-resistant strains of coagulase-negative staphylococci (CNS) was assessed to demonstrate the heterogeneity of this group of bacteria and estimate the chance of the efficacy of such therapy. The strains belonged to four species: Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus cohnii, Staphylococcus hominis. They originated from a hospital environment and from the skin of medical staff of the intensive care unit of a paediatric ward at a university hospital. All strains were methicillin-resistant, according to CLSI standards, but individual strains differed in MIC(ox) values. Susceptibility to other tested antibiotics was also characteristic for the species. The increased susceptibility to antibiotics in combinations, tested by calculating the fractional inhibitory concentration (FIC) index, concerned 26 out of 37 investigated strains and it was a feature of a particular species. Combinations of vancomycin and cephalotin against S. epidermidis and oxacillin with vancomycin were significant, as well as cephalotin and rifampicin in growth inhibition of multiresistant S. haemolyticus strains.     

Experimental grounds for the effectiveness of ciprofloxacin and oxytocin combined use

In order to determine the influence of combined use of ciprofloxacin and oxytocin on susceptibility of microflora to antibiotics as well as level of microbial anti-lysozyme (ALA) and anti-complement activity (ACA) 148 anaerobic and aerobic microorganisms were isolated from 80 patients with purulent infections of soft tissues. Susceptibility of staphylococci, streptococci, and enterobacteria to the most commonly used antibiotics was assessed by agar-diffusion method with standard disks. ALA and ACA of the isolated strains were defined by routine methods. Minimal inhibitory concentration (MIC) of ciprofloxacin and oxytocin for isolated pathogens were determined according to standards of NCCLS. Influence of oxytocin on MIC of ciprofloxacin was determined as well as inhibitory effect of the latter on factors of bacterial persistence. Decrease of MIC of ciprofloxacin as well as increase of its inhibitory effect on pathogens' ALA and ACA when it used in combination with oxytocin were noted. Usefulness of combined use of ciprofloxacin and oxytocin for treatment of different infections has been proposed.     

The production of ginsenosides in hairy root cultures of American Ginseng, Panax quinquefolium L. and their antimicrobial activity

Panax quinquefolium, American ginseng, is valued for its triterpene saponins, known as ginsenosides. These constituents possess a number of pharmacological properties and hairy root cultures can synthesize similar saponins to those of field-cultivated roots. The antibacterial activity of extracts from three hairy root clones of P. quinquefolium L. was tested against a range of standard bacterial and yeast strains. The agar diffusion method was used to evaluate inhibition of microbial growth at various extract concentrations. Commercial antibiotics were used as positive reference standards to determine the sensitivity of the strains. Susceptibility testing to antibiotics was also tested using the disk diffusion method. The minimal inhibitory concentration values of the extracts, obtained by agar diffusion, ranged from 0.8 to 1.4 mg/ml. The results showed that extracts from hairy root cultures inhibited the growth of bacteria and yeast strains and suggest that they may be useful in the treatment of infections caused by pathogenic microorganisms.     

Prevalence and distribution of Listeria pathogens in the final effluents of a rural wastewater treatment facility in the Eastern Cape Province of South Africa

We assessed the prevalence of free-living and plankton-associated Listeria species in the final effluents of a South African wastewater treatment facility and its receiving watershed between August 2007 and July 2008 as well as the antibiotic susceptibilities of effluent isolates. The physicochemical quality of the raw sewage and treated effluents was also determined. Free-living Listeria were more prevalent (96%), compared to plankton-associated Listeria species (58–67%). Listeria pathogens were sensitive to 11 (55%) of the 20 tested antibiotics, and showed varying (7–71%) levels of resistance to eight antibiotics. Turbidity, COD, NO₃, PO₄ and Listeria density fell short of recommended standards after treatment; while pH, temperature, TDS, DO and NO₂ were compliant with target quality after treatment. We conclude that final effluents of wastewater treatment plants are potential sources of Listeria pathogens in the aquatic milieu of South Africa.     

Simplified, Accurate Method for Antibiotic Assay of Clinical Specimens

Large glass plates are used for this modified agar-well diffusion assay method, allowing up to 81 replications on a single plate. With a specially designed agar punch, it is possible to prepare the small agar wells very quickly. The saving in serum resulting from fewer replications of standards with the large plates, and the small volume of the agar wells, makes it economically feasible to use pooled human serum for the standard antibiotic solutions. Methods are described for preparing the standard solutions, and for providing controls for the deterioration of standards and unknowns. Procedures for preparing and maintaining the commonly used assay organisms are presented. Serum specimens are tested directly rather than diluting them to a narrow range of antibiotic concentrations. This is possible because of a procedure for calculations that recognizes the curvilinear relationship between zone sizes and antibiotic concentrations. Adaptation of this method to a number of the commonly used antibiotics is described. With this method, it has been possible to test large numbers of clinical specimens in a minimal time, and with accuracy consistently better than 10%.     

呼吸内科病原菌的分布及耐药情况

目的：对十堰市人民医院2011年呼吸内科病原菌的分布及耐药情况进行研究,为临床合理使用抗菌药物及控制医院感染提供依据。方法：采用临床流行病学调查方法回顾性收集分析2011年1月-2011年12月呼吸内科病原菌分布及主要病原菌耐药率,对分离鉴定出的病原菌选用常用抗生素进行药敏实验,实验采用K-B法按NCCLS标准进行。结果：病原菌以革兰阴性杆菌为主,其中又以肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌为主,革兰阳性球菌以金黄色葡萄球菌为主。产酶和不产酶肺炎克雷伯菌、大肠埃希菌及金黄色葡萄球菌耐药率有明显差异。铜绿假单胞菌对头孢噻肟、氨曲南耐药率较高。结论：应根据药敏结果合理使用抗生素,以提高治疗效果,减少耐药菌株产生,预防医院内感染。     

The prophylactic use of antibiotics in cell culture

This article describes the historical development of the prophylactic use of antibiotics in cell culture as well as their effects on cells. The influence of antibiotics on cell morphology, cellular degeneration and cell death and cellular function is summarized. Cellular DNA as well as protein synthesis are affected which can lead to interference with, or even changes in, metabolic processes. Such effects must be considered in cell culture research. As antibiotics are used in multifold ways, the otherwise standardized conditions in cell culture are no longer comparable. The prophylactic use of antibiotics is rejected for scientific reasons.     

细菌生物膜研究技术

细菌生物膜是细菌生长过程中为适应生存环境而在固体表面上生长的一种与游走态细胞相对应的存在形式。只要条件允许,绝大多数细菌都可以形成生物膜。一旦形成了生物膜细菌就具有极强的耐药性,在医疗、食品、工业、军事等诸多领域给人类社会带来了严重的危害,造成巨大的经济损失。因此,细菌生物膜已成为全球关注的重大难题,也是目前科学界研究的前沿和热点。本文结合细菌生物膜研究技术的最新进展,重点介绍了几种常用生物膜发生装置及检测量化技术,并对其原理及优缺点进行了讨论。     

Determinants of resistance to chlortetracycline and other antibiotics in chlortetracycline-producing strain of Streptomyces aureofaciens

Data are presented on resistance of Streptomyces aureofaciens strain TB-633 FU--the producer of chlortetracycline (CTC) to autogenous antibiotics and a number of other antibiotics. It is demonstrated that resistance to CTC is specified by ctr genes of constitutive expression as well as by inducible genes. CTC and ethidium bromide may serve as efficient inductors of inducible ctr genes. The induction process is accompanied by increase in antibiotic biosynthesis level. Genes responsible for strain resistance to a number of macrolide antibiotics and thiostrepton are inducible and only function in the presence of appropriate antibiotics in the medium. The action of inducible mtr gene(s) is described in detail. The gene(s) simultaneously ensure increase in resistance to CTC and a number of macrolide antibiotics in the presence of exogenous inductors in media, such as both CTC and macrolide antibiotics. Mutants have been isolated which provide constitutive level of resistance to these antibiotics. A series of ctr and mtr mutants have increased CTC biosynthesis as compared to the initial level. Data on comparative analysis of the results obtained from hybridization of fragments of S. aureofaciens and S. rimosus DNAs to actI and actIII genes, responsible for polyketide synthases' synthesis, demonstrate that genes for CTC and OTC biosynthesis are situated on DNA fragments of similar size. This determines the strategy for cloning ctr and mtr genes as well as genes for CTC biosynthesis from S. aureofaciens.     

Disinfection of human skin allografts in tissue banking: a systematic review report

The use of skin allografts to temporarily replace lost or damaged skin is practiced worldwide. Naturally occurring contamination can be present on skin or can be introduced at recovery or during processing. This contamination can pose a threat to allograft recipients. Bacterial culture and disinfection of allografts are mandated, but the specific practices and methodologies are not dictated by standards. A systematic review of literature from three databases found 12 research articles that evaluated bioburden reduction processes of skin grafts. The use of broad spectrum antibiotics and antifungal agents was the most frequently identified disinfection method reported demonstrating reductions in contamination rates. It was determined that the greatest reduction in the skin allograft contamination rates utilized 0.1 % peracetic acid or 25 kGy of gamma irradiation at lower temperatures.     

A first global analysis of plasmid encoded proteins in the ACLAME database

Many plasmids are mobile genetic elements (MGEs) and, as other members of that group of DNA entities, their genomes display a mosaic and combinatorial structure, making their classification extremely difficult. As other MGEs, plasmids play a major role in horizontal transfer of genetic materials and genome reorganization. Yet, the full impact of such phenomenon on major properties of the host cell, such as pathogenicity, the ability to use new carbon sources or resistance to antibiotics, remains to be fully assessed. More and more complete plasmid genome sequences are available. However, in the absence of standards for storing plasmid sequence data and annotating genes and gene products on sequenced plasmid genomes, the resulting information remains rather limited. Using 503 sequenced plasmids organized in the ACLAME database, we discuss how, by structuring information on the genomes, their host and the proteins they code for, one can gain access to either global or more detailed analysis of the plasmid sequence information, as illustrated by a network representation of the relationships between plasmids.     

Effect of polyene antibiotics and their perhydrovderivatives on intact cells and protoplasts of yeast Candida guilliermondii]

Perhydroderivatives of polyene antibiotics have a much lower activity against eukaryotic cells than the polyene antibiotics itself. Bacterial cells are normally resistant against most polyene antibiotics and their perhydroderivatives. In earlier experiments with wall less L-form cells of Escherichia coli we have shown that the bacterial cell wall may be responsible for the resistance of the intact bacterial cells against polyene antibiotics and their perhydroderivatives by masking internal target sites. In the present paper we studied the effect of polyene antibiotics and their perhydroderivatives on intact cells and protoplasts of Candida guilliermondii. Our experiments have shown that most of the perhydroderivatives studied had a lower activity against intact cells as well as protoplasts than the corresponding polyene antibiotics. This means that in the case of eukaryotic cells the cell wall as a penetration barrier cannot mainly be responsible for the low activity of perhydroderivatives. The results are compared with those obtained previously with intact cells and protoplast type L-form cells of E. coli.     

Antibiotic therapy for ocular infection.

Infections of the eye can rapidly damage important functional structures and lead to permanent vision loss or blindness. Broad-spectrum antibiotics should be administered to the appropriate site of infection as soon as a diagnosis is made. Topical drops are preferred for corneal and conjunctival infections. Intravitreal antibiotics, and possibly subconjunctival and parenteral antibiotics, are preferred for endophthalmitis. Parenteral antibiotics are recommended for infection in deep adnexal structures. We review specific aspects of antibiotic therapy for ocular and periocular infection.     

Effects of borohydride-treated oligomycins on processes of energy transduction in mitochondria

Sodium borohydride in ethanol solution under mild conditions brings about the stepwise reduction of the 7-keto and the 11-keto groups of rutamycin and the oligomycins to the corresponding hydroxyl groups without further alterations of the macrocyclic lactone structure or other features of the molecule. The reduced compounds, as well as the parent antibiotics, inhibit the ADP-dependent (state 3) respiration, and the Pi formation and proton extrusion that are linked to ATP hydrolysis, but have no effect on other respiration-linked activities in intact rat liver mitochondria. Analogous inhibitory effects of borohydride-treated antibiotics are also observed in rat-liver submitochondrial particles. The reduced compounds are less potent inhibitors than the parent antibiotics. The reduced compounds are more efficient as inhibitors of Pi formation stimulated by conventional uncouplers (e.g. 2,4-dinitrophenol), than of Pi formation stimulated by certain amine-fluorescamine modifiers (e.g.) the benzylamine-fluorescamine compound. In contrast, the parent antibiotics are unable to discriminate between uncoupler-stimulated and modifier-stimulated Pi formation. It is suggested that rutamycin and the oligomycins bind to H+-ATPase as a result of hydrogen bonding to, at least, the 7-keto and/or the 11-keto groups of the antibiotics. When these keto groups are reduced to hydroxyl groups the hydrogen-bonding is less efficient due to the pronounced directional characteristic of hydrogen-bonding to keto groups.     

The Structure and Expression of Amylase Genes in Mammals: an Overview

Abstract

Austria is a small European country with a small number of universities and biotechnological industries, but with great efforts in the implementation of environmental consciousness and corresponding legal standards. This review attempts to describe the biotechnological landscape of Austria, thereby focusing on the highlights in research by industry, universities, and research laboratories, as published during 1990 to early 1995. These will include microbial metabolite (organic acids, antibiotics) and biopolymer (polyhydroxibutyrate, S-layers) production; enzyme (cellulases, hemicellulases, ligninases) technology and biocatalysis; environmental biotechnology; plant breeding and plant protection; mammalian cell products; fermenter design; and bioprocess engineering.     

抗生素含量测定方法的分析概述

抗生素作为一种抗菌物质,在现代医疗中起着非常重要的作用。2015版中华人民共和国药典共收录抗生素药品363种,所介绍的抗生素含量测定方法有4种。根据抗生素测定方法的统计,在这363种抗生素中,有275种采用高效液相色谱法;有75种采用抗生素微生物检定法;有8 种采用紫外-可见分光光度法;只有5种采用了滴定法。以最新的2015版中华人民共和国药典为基础,对抗生素的测定方法进行了分析概述,期望能在环境抗生素残留量的测定方面提供可借鉴的内容。     

New dithiolopyrrolone antibiotics induced by adding sorbic acid to the culture medium of Saccharothrix algeriensis NRRL B-24137

Dithiolopyrrolone antibiotics, produced by several microorganisms, are known for their strong antimicrobial activities. This class of antibiotics generated new interest after the discovery of their anticancer and antitumor properties. In this study, four new antibiotics were purified from the fermentation broth of Saccharothrix algeriensis NRRL B-24137 and characterized as dithiolopyrrolone derivatives. These new dithiolopyrrolone antibiotics were induced by adding sorbic acid, as precursor, at a concentration of 5 mM to the semi-synthetic medium. The analysis of the induced antibiotics was carried out by HPLC. The maximal production of the antibiotics PR2, PR8, PR9 and PR10 was 0.08±0.04, 0.21±0.04, 0.13±0.03 and 0.09±0.00 mg L(-1) , respectively, obtained after 8 days of fermentation. The chemical structures of these antibiotics were determined by (1) H- and (13) C-nuclear magnetic resonance, mass and UV-visible data. The four new dithiolopyrrolone antibiotics - PR2, PR8, PR9 and PR10 - were characterized, respectively, as crotonyl-pyrrothine, sorbyl-pyrrothine, 2-hexonyl-pyrrothine and 2-methyl-3-pentenyl-pyrrothine. The minimum inhibitory concentrations of the new induced antibiotics were determined.     

Biosensor Systems for Antibiotic Detection

Antibiotics are widely used in medicine, veterinary medicine, and the food industry. However, the active use of antibacterial drugs leads to environmental pollution. In this regard, there is a great need for monitoring and determining antibiotics in various environments such as drinking water, food, drinks, waste water from pharmaceutical factories, etc. A number of methods, including those based on biosensors, have been developed to determine antibiotics. Biosensor methods of analysis are widely used and are an integral part of environmental monitoring. Electrochemical, optical, acoustic, microbial biosensors, immuno- and aptasensors, as well as sensors based on molecularly imprinted polymers are in the most demand for the analysis of antibiotics. This article provides a brief overview of biosensor methods and approaches for the determination of antibiotics. The most promising biosensor systems for determining antibacterial drugs were analyzed.