慢性前列腺炎患者前列腺抗生素活性的检测

检测以口服、肌肉注射射或静脉注射给药治疗前后慢性前列患者前列腺液内微生物的性质与数量,抗菌药物活性及观察患者症状的变化,判断抗菌药物对慢性前列腺炎前列腺组织的透过性,探讨常规途径与方法给药治疗慢性前列腺炎的可行性。结果表明,１８５例慢性前列腺炎患者的前列腺液内都可检出细菌、支原体、真菌或衣原体,其中以革兰阳性细菌最多见。根据药物敏感试验结果选用菌药物,不论以口服、肌肉注射或是静脉注射给药治疗后,前     

Colorimetric evaluation of the time-killing assay for Citropin 1.1, lipopeptide Palm-KK-NH2, and Temporin A

Nowadays, there are a number of colorimetric techniques available for the determination of a time killing assay in a manner much easier and faster than those previously more commonly used, which were much more time-consuming and laborious colony counting procedures. Here, an attempt has been made to test the antimicrobial peptides of Citropin 1.1, Palm-KK-NH2, and Temporin A on a reference strain of Staphylococcus aureus using resazurin as the cell viability reagent. Staphylococcus aureus was exposed to the test compounds over varying periods of time and the metabolic activity measured, with a profile of antimicrobial activity then established. The results are in agreement with data from previous literature, thus confirming the relevance of the application of resazurin for the testing of antimicrobial agents.     

Quantitative aspects of phenyl substituted alcohol and ether bacteriostatic interaction with Escherichia coli B/5.

It is well established that compounds of the class phenylalkane alcohols and ethers exert their antimicrobial action on the bacterial envelope--probably on the membrane. However, the overall stoichiometry, the number of molecules bound vs those merely added per cell, and the kinds of equilibria involved (site binding vs equipartitioning) are not clear. This work examines antimicrobial action on E. coli B/5 with eight such compounds. Directly determined binding data, plate counting viabilities, radiorespirometry, and microcalorimetry of glucose utilization were evaluated. The compounds mostly bind by simply equipartitioning, up to some threshold level, short of kill. That level depends sharply on the number of alkane carbons in the phenyl alkane derivative, but not on the precise structure. Past the threshold, bacteriostatic action is sudden and complete, probably reflecting cooperative behaviour in the cell envelope. The amount of bound compound at the threshold level is only about 0.5 to 3% of the weight of the bacterial envelope hydrocarbon, when bacteriostasis occurs. There is an unexpectedly small dependence on cell concentration. The principal governors on where the monooxygen phenylalkanes kill cells seems to be merely their concentration or chemical potential, the number of aliphatic carbons, and the binding mechanism. Because of the cell concentration independence, the cells act as if they constituted a second phase, relative to the solution. Results from the microcalorimetric method for assay of bacteriostasis correlate well with those from plate counting or viability assays.     

The influence of the method of sampling on the accuracy of the determination of bacterial numbers in the soil

Summary Tests were made to determine the influence of the sampling and the preparatory treatment of the samples on the counting of bacteria in the soil. These proved that the present methods are very inaccurate and give rise to considerable variance in parallel determinations, to the extent even of rendering the effect of a perfected counting procedure quite negligible.In this connection it has been stated that it is useless to aim at a minute counting of bacteria, as only the number of microbes in the ultimate soil suspension would thus be determined, whereas this suspension is by no means accurately representative of the tested soil.For a better preparatory treatment of the samples a homogeneisation method by means of a porcelan ball mill was worked out, according to which a suspension is made of the sample with water, which method has given satisfactory results.Finally, the determination of various chemical substances, apart from the counting of microbes, has been included in our tests. Here also an improvement in the treatment of the samples was arrived at.     

Determination of essential and variable residues in pediocin PA-1 by NNK scanning

Pediocin PA-1 is an antimicrobial peptide (called bacteriocin) that shows inhibitory activity against the food-borne pathogen Listeria monocytogenes. To elucidate which residue(s) is responsible for this function, the antimicrobial activities of pediocin PA-1 mutants were evaluated and compared. Each of the 44 native codons was replaced with the NNK triplet oligonucleotide in a technique termed NNK scanning, and 35 mutations at each position were examined for antimicrobial activities using a modified colony overlay screening method. As a consequence, the functional responsibility of each residue was estimated by counting the number of active mutants, allowing us to identify candidate essential/variable residues. Activity was abrogated by many of the mutations at residues Y2, G6, C9, C14, C24, W33, G37, and C44, indicating that these residues may be essential. In contrast, activity was retained by almost all versions harboring mutations at K1, T8, G10, S13, G19, N28, and N41, indicating that these are functionally redundant residues. Sequence analysis revealed that only the wild type was active and 14 and 11 substitutions were inactive at G6 and C14, respectively, while 12 and 11 substitutions were active and 2 and 0 substitutions were inactive at T8 and K1, respectively. These findings suggest that NNK scanning is effective for determining essential and variable residues in pediocin PA-1, leading to an elucidation of structure-function relationships and to improvements in the antimicrobial function efficiently by peptide engineering.     

Determination of Essential and Variable Residues in Pediocin PA-1 by NNK Scanning

Pediocin PA-1 is an antimicrobial peptide (called bacteriocin) that shows inhibitory activity against the food-borne pathogen Listeria monocytogenes. To elucidate which residue(s) is responsible for this function, the antimicrobial activities of pediocin PA-1 mutants were evaluated and compared. Each of the 44 native codons was replaced with the NNK triplet oligonucleotide in a technique termed NNK scanning, and 35 mutations at each position were examined for antimicrobial activities using a modified colony overlay screening method. As a consequence, the functional responsibility of each residue was estimated by counting the number of active mutants, allowing us to identify candidate essential/variable residues. Activity was abrogated by many of the mutations at residues Y2, G6, C9, C14, C24, W33, G37, and C44, indicating that these residues may be essential. In contrast, activity was retained by almost all versions harboring mutations at K1, T8, G10, S13, G19, N28, and N41, indicating that these are functionally redundant residues. Sequence analysis revealed that only the wild type was active and 14 and 11 substitutions were inactive at G6 and C14, respectively, while 12 and 11 substitutions were active and 2 and 0 substitutions were inactive at T8 and K1, respectively. These findings suggest that NNK scanning is effective for determining essential and variable residues in pediocin PA-1, leading to an elucidation of structure-function relationships and to improvements in the antimicrobial function efficiently by peptide engineering.     

浮游甲壳类定量采样计数方法评价

１引言浮游生物是养殖鱼类特别是滤食性鱼类的主要饵料,同时又是评价水生态系统质量优劣的重要指标．在大水面增养殖研究中,常常通过水体中浮游生物的采样分析,计算水体生物生产力．而在池塘生态系统中则又常常借助于浮游生物的采样分析来判定养鱼水质,决定增施饵肥料...     

A method for the enumeration of bacterial adhesion to epithelial cells using image analysis

Abstract Computerised image analysis was utilised to enumerate the attachment of Staphylococcus epidermidis to HEp2 cell monolayers. A differential staining technique was employed such that individual staphylococcal cells stood out in sharp contrast against the uneven cell surface and granular contents of the epithelial cells. The primary image analysis operation involved subtracting an out-of-focus image from an in-focus image of the bacteria on the monolayer, thereby accentuating the bacterial image. Enumeration, using a particle counting routine, was rapid and reproducible, facilitating counting in excess of 700 bacteria per field at ×500 magnification. The computerised programme compared favourably with manual counting and would provide a rapid, objective and morphologically discriminatory method for evaluating bacterial attachment to various tissues.     

A novel approach to pharmacodynamic assessment of antimicrobial agents: new insights to dosing regimen design

Pharmacodynamic modeling has been increasingly used as a decision support tool to guide dosing regimen selection, both in the drug development and clinical settings. Killing by antimicrobial agents has been traditionally classified categorically as concentration-dependent (which would favor less fractionating regimens) or time-dependent (for which more frequent dosing is preferred). While intuitive and useful to explain empiric data, a more informative approach is necessary to provide a robust assessment of pharmacodynamic profiles in situations other than the extremes of the spectrum (e.g., agents which exhibit partial concentration-dependent killing). A quantitative approach to describe the interaction of an antimicrobial agent and a pathogen is proposed to fill this unmet need. A hypothetic antimicrobial agent with linear pharmacokinetics is used for illustrative purposes. A non-linear functional form (sigmoid Emax) of killing consisted of 3 parameters is used. Using different parameter values in conjunction with the relative growth rate of the pathogen and antimicrobial agent concentration ranges, various conventional pharmacodynamic surrogate indices (e.g., AUC/MIC, Cmax/MIC, %T>MIC) could be satisfactorily linked to outcomes. In addition, the dosing intensity represented by the average kill rate of a dosing regimen can be derived, which could be used for quantitative comparison. The relevance of our approach is further supported by experimental data from our previous investigations using a variety of gram-negative bacteria and antimicrobial agents (moxifloxacin, levofloxacin, gentamicin, amikacin and meropenem). The pharmacodynamic profiles of a wide range of antimicrobial agents can be assessed by a more flexible computational tool to support dosing selection.     

Rapid screening method for the detection of antimicrobial substances

Bioluminescence is phenomenon where living organisms produce light and this production is directly dependent on metabolic activity of the organism. Genes encoding enzymes, luciferases, responsible for light production can be cloned into indicator strains, thus allowing sensitive detection of antimicrobial activity. This study utilized bacterial luciferase genes cloned into Staphylococcus aureus, Escherichia coli and Salmonella enterica serovar Typhimurium indicator strains and showed that the detection of antimicrobial activity can be obtained already in 2 h without laborious plate counting and overnight incubation. Indicator strains used in the study harboured luxAB genes responsible of producing light as well as luxCDE genes for synthesis of long-chain fatty aldehyde as substrate for light production. As a consequence, no exogenous aldehyde addition was needed allowing stable light production. Furthermore, the method was used for the detection of antimicrobial activity from lactic acid bacteria after the effect of organic acids was eliminated.     

Antimicrobial mortar surfaces for the improvement of hygienic conditions

Aims:  To evaluate the effectiveness of various antimicrobial mortar formulations in inhibiting the growth of a selection of pathogens of environmental and hygienic concern.
Methods and Results:  Mortar prisms containing triclosan-incorporated fibres or different concentrations of silver copper zeolites were incubated with Escherichia coli , Listeria monocytogenes , Salmonella enterica or Staphylococcus aureus at 4 or 20°C for 24 h. From plate counting, a substantial bactericidal effect (>4 log units) could only be observed for the mortar specimens containing more than 3% zeolites on cement weight base, the effect being more pronounced at 20°C compared to 4°C. No inhibitory effect could be observed for mortar specimens containing antimicrobial fibres. Adenosinetriphosphate (ATP) measurements allowed for a rapid indication of the occurrence of antimicrobial activity.
Conclusions:  In order to obtain a bactericidal effect on mortar surfaces, concentrations of silver copper zeolites of more then 3% are required.
Significance and Impact of the Study:  To our knowledge, this is the first study in which the effectiveness of various antimicrobial mortar mixtures towards the inhibition of pathogens has been evaluated in a quantitative way. Antimicrobial concrete mixtures can be used for the improvement of the hygienic conditions in a variety of environments.     

Double‐Counting in Life Cycle Calculations

Many popular frameworks apply life cycle calculations to examine environmental burdens occurring throughout the life cycle of products and services that are either purchased by final consumers or demanded as inputs by producers. Accounting for the full supply chain of producer items can lead to double‐counting effects when results of separate studies are added up and referenced or compared to totals. If, for instance, energy life cycle inventories were prepared for all consumer and producer items in an economy and added up, the resulting total amount of energy would be greater than national energy consumption. Although this double‐counting is inconsequential if analyses are appraised in isolation without reference to national totals, it leads to serious errors when large interconnected systems are analyzed or when results are placed into wider (e.g., regional, national, or global) contexts. The article lists a number of prominent policy and decision‐making frameworks that make use of life cycle techniques, where this double‐counting error is highly undesirable. It proposes a solution to the double‐counting problem in which supply chains in the product life cycle are split and burdens shared between the supplying and demanding sides of every transaction in the economy.     

Anti-adhesive and antibacterial properties of a proprietary denture cleanser

The antimicrobial efficacy and anti-adhesive attributes of a proprietary denture cleanser were evaluated. To determine cleanser antimicrobial efficacy, Streptococcus mutans was grown on denture acrylic strips which were then exposed to the cleanser. To evaluate anti-adhesive efficacy, the strips were treated with the cleanser and then placed in the Strep. mutans suspension. Following incubation, adhered bacteria were removed and enumerated by viable counting. Treated denture acrylic plates were also placed in a parallel-plate flow chamber and then exposed to Strep. oralis. Images of adhered bacteria were analysed to determine biofilm coverage. Biofilm removal force was quantified by increasing the flow rate between the acrylic plates. The cleanser exhibited a 100% kill against Strep. mutans adhered to the acrylic surface, and inhibited attachment of cells by 66%. The flow chamber study found that cleanser-treated denture acrylic allowed the formation of a multilayer biofilm which was easily removed by a slight increase in flow rate.     

Synthesis, antitubercular and antimicrobial evaluation of 3-(4-chlorophenyl)-4-substituted pyrazole derivatives

As a part of our research to develop novel antitubercular and antimicrobial agents, a series of 3-(4-chlorophenyl)-4-substituted pyrazoles have been synthesised. These compounds were tested for antitubercular activity in vitro against Mycobacterium tuberculosis H37Rv strain using the BACTEC 460 radiometric system, antifungal activity against a pathogenic strain of fungi and antibacterial activity against gram-positive and gram-negative organisms. Among them tested, many compounds showed good to excellent antimicrobial and antitubercular activity. The results suggest that hydrazones, 2-azetidinones and 4-thiazolidinones bearing a core pyrazole scaffold would be potent antimicrobial and antitubercular agents.     

Marked increase in membranolytic selectivity of novel cyclic tachyplesins constrained with an antiparallel two-beta strand cystine knot framework

We have developed a highly constrained 18-residue cyclic peptide template based on the antimicrobial peptide tachyplesin-1 that features an end-to-end peptide backbone and a cystine knot-like motif with three evenly spaced disulfide bonds to cross-brace the antiparallel beta-strands and to approximate an amphiphatic "beta-tile"-like structure. Six beta-tile analogs were prepared to correlate different topological patterns with membranolytic specificity. Their conformations and antimicrobial and hemolytic activities were compared with tachyplesin-1 and the recently discovered Rhesus monkey theta defensin (RTD) which contains similar beta-tile structural elements. The beta-tile peptides and RTD retained broad spectrum antimicrobial activities. In general, they were less active than tachyplesin-1 in 10 tested organisms but their activity increased under high-salt (100 mM NaCl) rather than in low-salt conditions. The beta-tile peptides are highly nontoxic to human erythrocytes with EC(25) ranging from 600 to 4000 microM. Collectively, our results show that the design of a highly rigid peptide template is useful for further analog study to dissociate antimicrobial activity from cytotoxicity which would be helpful in discovering clinical applications for peptide antibiotics.     

Interactions between naïve and infected macrophages reduce Mycobacterium tuberculosis viability

A high intracellular bacillary load of Mycobacterium tuberculosis in macrophages induces an atypical lysosomal cell death with early features of apoptosis that progress to necrosis within hours. Unlike classical apoptosis, this cell death mode does not appear to diminish M. tuberculosis viability. We previously reported that culturing heavily infected macrophages with na?ve macrophages produced an antimicrobial effect, but only if na?ve macrophages were added during the pre-necrotic phase of M. tuberculosis-induced cell death. In the present study we investigated the mechanism of antimicrobial activity in co-cultures, anticipating that efferocytosis of bacilli in apoptotic bodies would be required. Confocal microscopy revealed frustrated phagocytosis of M. tuberculosis-infected macrophages with no evidence that significant numbers of bacilli were transferred to the na?ve macrophages. The antimicrobial effect of na?ve macrophages was retained when they were separated from infected macrophages in transwells, and conditioned co-culture supernatants transferred antimicrobial activity to cultures of infected macrophages alone. Antimicrobial activity in macrophage co-cultures was abrogated when the na?ve population was deficient in IL-1 receptor or when the infected population was deficient in inducible nitric oxide synthase. The participation of nitric oxide suggested a conventional antimicrobial mechanism requiring delivery of bacilli to a late endosomal compartment. Using macrophages expressing GFP-LC3 we observed the induction of autophagy specifically by a high intracellular load of M. tuberculosis. Bacilli were identified in LC3-positive compartments and LC3-positive compartments were confirmed to be acidified and LAMP1 positive. Thus, the antimicrobial effect of na?ve macrophages acting on M. tuberculosis in heavily-infected macrophages is contact-independent. Interleukin-1 provides an afferent signal that induces an as yet unidentified small molecule which promotes nitric oxide-dependent antimicrobial activity against bacilli in autolysosomes of heavily infected macrophages. This cooperative, innate antimicrobial interaction may limit the maximal growth rate of M. tuberculosis prior to the expression of adaptive immunity in pulmonary tuberculosis.     

Lethal photosensitisation of oral bacteria and its potential application in the photodynamic therapy of oral infections.

Chemical antibacterial agents are increasingly being used in prophylactic and therapeutic regimes for dental plaque-related diseases, which are among the most common human infections. As these agents are difficult to maintain at a therapeutic concentration in the oral cavity and can be rendered ineffective by resistance development in the target organisms, there is a need to develop alternative antimicrobial approaches. Bacteria and other microbes can be sensitised to light through prior treatment with a chemical photosensitising agent. Lethal photosensitisation of a wide range of bacteria responsible for caries, periodontal diseases and root canal infections has been demonstrated using red light in conjunction with a number of photosensitisers, including Toluidine Blue, phthalocyanines and chlorins. The advantages of this approach are that bacteria can be eradicated in very short periods of time (seconds or minutes), resistance development in the target bacteria is unlikely and damage to adjacent host tissues and disruption of the normal microflora can be avoided. This approach may be a useful alternative to antibiotics and antiseptics in eliminating cariogenic and periodontopathogenic bacteria from disease lesions and for the disinfection of root canals. Not only would this be of benefit for the treatment of these diseases but, by replacing the antimicrobial agents that are currently used for such purposes, it would help to conserve our dwindling supply of antimicrobial agents that are effective in the treatment of serious systemic infections.