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A promising strategy to design safer and more effective cationic lipids for gene delivery with inherent antibacterial properties is to covalently tether a lipophilic moiety with oligomeric aminoglycosides (AGs), a large family of Gram-negative-active antibiotics. Herein, we reported the development of a new class of multicationic-head AG-based amphiphiles built on the tetramino-tetrahexyloxycalix[4]arene (4A4Hex-calix-calix[4]) scaffold. Three different conjugates, namely 4A4Hex-calix-calix[4]-neomycin, -neamine, and -paromomycin, were synthesized and characterized. Due to the inherent multivalency of AGs and the amphiphilic behaviour, every 4A4Hex-calix-calix[4]-AG exhibited greater DNA binding ability than the gold standard transfectant 25 kDa bPEI and striking DNA packing ability. DNA/4A4Hex-calix-calix[4]-AG complexes at charge ratios (CRs, +/-) used for transfections displayed good colloidal stability, with a hydrodynamic diameters of ≈150 nm and an overall surface charges of ≈+30 mV. DNA/4A4Hex-calix[4]-AGs nanoassemblies, everyone tested at the optimal CR, invariably showed good transfection efficiency in two cell lines, along with low-to-negligible cytotoxicity. Besides, DNA/4A4Hex-calix-calix[4]-AG complexes exhibited appreciable antimicrobial activity against Gram-negative bacteria, even greater than uncomplexed 4A4Hex-calix-calix[4]-AGs. Altogether, these results disclose 4A4Hex-calix[4]-AGs as promising gene delivery tools with unique antibacterial properties., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The article presents results of bacteriological research of a secret of prostate gland and blood serum on test-culture Sercina lutera ATSS 9341 in 57 patients with chronic bacterial prostatitis along with ampicillin sodium application through lymph and intramuscular injection of the antibiotic.

In this study, certain 3-methyl-2-[4-(substituted amino carbonyl)anilino] quinoxalines, (2a-d) and (3a-d), were synthesized from the new key compound 2-[4-(ethoxycarbonyl)anilino]-3-methyl quinoxaline (1). In addition, a series of 2-[4-(arylidene hydrazinocarbonyl)anilino]-3-methyl quinoxalines (5a-e), as well as their cyclized oxadiazolinyl derivatives (6a-e), and a series of 2-[4-N2-acylhydrazinocarbonyl) anilino]-3-methyl quinoxalines (7a-d), as well as their cyclized oxadiazoiyl derivatives (8a-d) were also prepared. Some of these derivatives were evaluated for antimicrobial activity in vitro. It was found that all the selected compounds exhibit antimicrobial activity and that compound 5b had a broad spectrum of activity.

Complex formation between streptomycin sulfate and poly(acrylic acid) has been studied in aqueous solutions by turbidimetric, potentiometric and viscometric methods as well as by FTIR spectroscopy. It was shown that these polycomplexes are stabilized by electrostatic interactions. The solubility of polycomplexes was examined as a function of pH and it was found that at pH values below 3.1 the polycomplexes undergo complete dissociation or dissolution. The antimicrobial activity of the drug and its polycomplex was evaluated using Sarcina sp. as a model organism. It was demonstrated that the polycomplexes have an antimicrobial activity on the same level as the free drug.

We report here the development of bacterial chain reaction (BCR), a system using micro organisms as nanodevices to amplify and visualize signals from molecular bioprobes such as antibodies, binding proteins, lectins, and oligonucleotides. Unlike conventional enzyme-linked amplification systems in which the amount of enzyme is a constant parameter, in the BCR an enzyme (penicillinase) is used to trigger a proliferative chain reaction producing an exponential increase in enzyme. The detection limits and specificity of BCR were determined using a model system designed to detect and enumerate MCF-7 (a human breast adenocarcinoma cell line) cells disseminated at extremely low frequency (e.g., one tumor cell per million normal cells) among monocluclear cells (MNCs) of human peripheral blood. Results of testing 83 specimens of peripheral blood from presumably healthy donors showed 97.6% specificity. The system was capable of detecting tumor cells at a frequency of 2 x 10(-7).

Pyruvate decarboxylase from the obligate anaerobe Sarcina ventriculi was purified eightfold. The subunit Mr was 57,000 +/- 3000 as estimated from SDS-PAGE, and the native Mr estimated by gel filtration on a Superose 6 column was 240,000, indicating that the enzyme is a tetramer. The Mr values are comparable to those for pyruvate decarboxylase from Zymomonas mobilis and Saccharomyces cerevisiae, which are also tetrameric enzymes. The enzyme was oxygen stable, and had a pH optimum within the range 6.3-6.7. It displayed sigmoidal kinetics for pyruvate, with a S0.5 of 13 mM, kinetic properties also found for pyruvate decarboxylase from yeast and differing from the Michaelis-Menten kinetics of the enzyme from Z. mobilis. No activators were found. p-Chloromercuribenzoate inhibited activity and the inhibition was reversed by the addition of dithiothreitol, indicating that cysteine is important in the active site. The N-terminal amino acid sequence of pyruvate decarboxylase was more similar to the sequence of S. cerevisiae than Z. mobilis pyruvate decarboxylase.

The performance of a liquid chromatographic (LC) method for spiramycin measurement in bovine plasma has been compared with that of a microbiological method. Plasma samples were obtained from cattle administered spiramycin intravenously. Comparison tests used were intraclass correlation (r1), correlation (r), and Student's paired t-test. For concentrations lower than 2.5 IU/mL, microbiological values were higher than LC values. This difference in results modified pharmacokinetic interpretation and might be explained by the presence of microbiologically active metabolites.

The suitability of disinfection preparations is assessed on the basis of laboratory tests, different methods being used in the various countries. Since such model tests are rather inadequate when it comes to judging surface disinfectants, additional in-use tests are desirable. They might, in any case, serve as a reference system for judging the evaluation criteria which still differ widely at the moment. The experiments described in this study were chiefly designed to establish the effect of cleaning and disinfection measures on bacteria normally present on surfaces and on the artificial contamination of surfaces with Sarcinae as model germs. The tests were carried out in the halls on 5 floors of a medical (lift landings). "Rodac" plates were used to identify the germs. 3 disinfectants (aldehydes, phenol derivative), 3 disinfectant cleaning agents and soft soap were used. The preparations reduced the normal germ count by approx. 80 per cent. The reduction was mainly due to the cleaning effect (soft soap was as effective as the preparations with disinfectant properties). The effect on the "normal germ count" cannot, therefore, be used as sole criterion of disinfectant action. When the various preparations were applied in twice the concentration recommended for Staphylococcus hospitalism, the Sarcina count was reduced by 99 to 99.9 per cent within 2 hours. The efficacy of disinfectants and disinfectant cleaning agents was practically the same. Additional laboratory tests are necessary before the effect of soft soap can be finally assessed. In actual practice the unit count of pathogenic germs- such as Staphylococci and Klebsiellae- is too low to enable an objective assessment of a disinfectant to be made. On the other hand, artificial contamination with such pathogens is not possible because of the risk involved. The use of Sarcina lutea as test germ is therefore subjects to certain limitations. One of the prerequisites for using it is, for example, prior reduction of the normal germ count to values of less than 500/100 cm2. The second communication will report on investigations into the chemoresistance of Sarcina and how this compares with that of Staphylococcus aureus and Klebsiella. The need for such studies arose from our present investigation.

The microbiological assay for penicillin residues was improved by using centrifugation to remove physical barriers to diffusion, a small buffer/meat extraction ratio, and a more sensitive 2-layer assay system. Recoveries from muscle, kidney, and liver tissues ranged between 70.1 and 86.7% with measurable levels of 0.03--0.05 unit/g. By comparison, the Food and Drug-suggested methodology yielded recoveries of 45.9--54.0% and levels of detectability of 0.08--0.10 unit/g. Cooking of hamburger, steaks, and port chops indicated that procaine penicillin withstood cooking conditions, and significant levels of the original activity remained.

Sarcina marina (NCMB 778) grew over the temperature range 20-45 degrees C but no growth was recorded at 15 degrees C or 50 degrees C. At the optimum growth temperature of 34 degrees C the doubling time was 14.5 h. The major polar lipid components, tentatively identified as the diether analogues of phosphatidyl glycerophosphate (PGP), phosphatidyl glycerol (PG), diglycosyl diglyceride (DGD) and triglycosyl diglyceride (TGD), and the major neutral lipid components, tentatively identified as squalene, dihydrosqualene, tetrahydrosqualene, vitamin MK8, geranyl geraniol and di-O-phytanyl glycerol, are identical to those found in other extremely halophilic rods and cocci. The total lipid content varied with growth conditions from 0.6-3.2% of the dry cell weight, polar lipids accounted for between 94.3 and 83.6% of the total lipid, the remainder being neutral lipid. In response to both the transition from exponential to stationary phase and a reduction of 14 degrees C in growth temperature, batch cultures showed: (i) an increase in total lipid content; (ii) a decrease in PG and (iii) an increase in PGP. Specific responses to the temperature decrease were (i) increased total lipid content; (ii) no decrease in neutral lipids in stationary phase; (iii) marked reduction in PG and (iv) raised DGD. (i) and (ii) could be mechanisms for increasing membrane fluidity. In common with all other extreme halophiles investigated the alkyl side chains of S. marina polar lipids were identified as the phytanyl (3R, 7R, 11R, 15-tetramethylhexadecyl) group. Its structure did not appear to vary with temperature so that the normal mechanisms for modifying the structure of lipid alkyl side chains to modulate membrane fluidity in response to temperature changes probably does not occur in this group of microorganisms.

Epidemiological investigations have demonstrated that insufficient hygiene in households results in increasing health hazards. In order to be able to recommend ways to disrupt infection chains it was necessary to explore the most important pathways of cross-contamination. Housewives without special training were instructed to prepare a complete meal, in the kitchen of a modern, vacant apartment. Among the raw products provided was minced meat, contaminated with Sarcinae (unbeknown to the housewives) in a quantitative manner. When cooking and cleaning procedures were completed we analysed household utensils and surfaces by Rodac impressions and swabs. The test organisms could be detected on all inspected surfaces and on the dining-table with albeit different frequencies. The following locations showed an especially high degree of cross-contamination: a) working-surfaces, especially boards of wood and plastics. b) cutting-machines, c) kitchen-machines. These results agree with literature data. By careful disinfection, i.e. by application of a 0.5% solution of hypochlorite, the contaminations could be removed. We assessed this when arranging the kitchen for the next test. Since it is impossible to practise disinfection procedures in a household kitchen on the same scale as in an operating room, we tried to achieve at least a limited disinfection by household cleansers with germicidal properties. In our opinion a minimum reduction of five log stages, demanded in the medical area, can not be achieved in a household kitchen and indeed it is not necessary. A reduction of the microbial counts to 10% of the original value would already be useful, as toxic levels of microbial counts will be reached later especially when there is simultaneous refrigeration. Correct dosage proved to be one of the main practical problems because a discrepancy exists between the low concentration of tensids, necessary for cleaning, and the relatively high dose necessary for germ-killing compounds. Diluted DOMESTOS proved to be a cleaning agent and germicide, but was, however, blamed for chlorine odour, especially when diluted with warm water. A greater acceptance level was reached with a peroxide-containing cleanser, which, however, was not sufficiently germicidal, when applied in diluted form. The concentrated formulation was more effective in everyday experience, but for this housewives had to wear rubber gloves. This was reported to be complicated and uncomfortable, and indeed the search for better formulations must be continued. (In communication II comparisons with the bibliography and hygienic consequences will be published.)

A microbiological assay method has been developed and applied to Neisseria gonorrhoeae, for the purpose of detecting enzymatic deactivation of benzyl penicillin. Calibration of the method, using strains of Escherichia coli K-12 with previously reported penicillinase (EC 3.5.2.6.) activities, has shown that it is extremely sensitive and may be used in a quantitative manner. At the limit of sensitivity the test is able to detect penicillin breakdown in the order of 3 X 10(-3) mug in 48 h, which is equivalent to about 7 X 10(-8) mumol/min per milligram dry weight of cells. Over 100 strains of N. gonorrhoeae, most of them resistant to penicillin, were screened for their ability to deactivate penicillin during 48 h of growth in the presence of subinhibitory levels. No deactivation was detected. It is concluded, from quantitative evidence, that reduced penicillin sensitivity in N. gonorrhoeae is not due to the enzymatic deactivation of the antibiotic.

When polyurethane foam test tube plugs are autoclaved, they release volatile fatty amines that inhibit the growth of some microorganisms. The chemical structures of these amines were determined by the use of a gas chromatograph-mass spectrometer. They are catalysts used to produce the foam. The problem of contaminating growth media with toxic substances released from polymeric materials is discussed.

Two methods described in the AOAC Official Methods of Analysis for the detection of penicillin residues in whole milk were evaluated to determine the capability of each method to detect residues of 12 antibiotics used in the dairy industry. The first method, a cylinder-plate method that uses Sarcina lutea as the test organism, detected levels of 1 ppm of 8 of the 12 antibiotics tested. The second method, using paper disks with Bacillus subtilis as the test organism, detected approximately 1 ppm of only 4 antibiotics. This disk method was unable to detect less than 40 ppm of 5 of the antibiotics tested. The data indicate that the S. lutea cylinder-plate technique is more sensitive to more antibiotics than the B. subtilis disk method and is far superior for screening purposes.

A study was made to develop a new method for the production of flavine-adenine dinucleotide (FAD) from riboflavine and adenine by a mutant of Sarcina lutea deficient in the enzyme adenosine deaminase. It was found that this strain could convert exogenously supplemented riboflavine to extracellular FAD. The yields of FAD were increased by addition of D-cycloserine in the culture medium. The culture conditions for FAD production were investigated under the addition of D-cycloserine, and increased production of FAD was observed with the addition of an appropriate amount of thiamine, acetate, and sodium ion. The yield of 0.7 g/liter was obtained in the optimal culture in 5 days. Accumulated FAD was readily isolated by adsorption chromatography and ion-exchange chromatography in a 70% yield.

Distinct morphological changes in the ultrastructure of Sarcina ventriculi were observed when cells were grown in medium of constant composition at pH extremes of 3.0 and 8.0. Transmission electron microscopy revealed that at low pH (less than or equal to 3.0) the cells formed regular packets and cell division was uniform. When the pH was increased (to greater than or equal to 7.0), the cells became larger and cell division resulted in irregular cells that varied in shape and size. Sporulation occurred at high pH (i.e., greater than or equal to 8.0). The sporulation cycle followed the conventional sequence of development for refractile endospores, with the appearance of a cortex and multiple wall layers. The spores were resistant to oxygen, lysozyme, or heating at 90 degrees C for 15 min. Spores germinated within the pH range of 4.6 to 7.0.

The microbiological assay for penicillin residues in milk was improved. Acidification of milk with phosphoric acid to pH 4.5, centrifugation to remove precipitated proteinaceous matter, adjustment of pH to 6.0, a second centrifugation, and the use of a 2% agar base layer resulted in the consistent measurement of 0.01 unit penicillin activity/ml milk. Sarcina lutea was used as the assay organism. Recoveries in milk averaged 94%, in nonfat dry milk 84%, in cottage cheese 97%, and in cream cheese 94%.

Generation time was determined in pure cultures of heterotrophic microorganisms in the conditions similar to those of Baikal in June--July of 1972. Generation time was found to be 37+/-7, 16+/-2.5, 16+/-3.2, and 10+/-2.5 hours, respectively, when the cultures had been diluted with Baikal water in the following rations: 1 : 0,1 : 5,1 : 10, and 1 : 20. No differences in the growth rate were found among 11 cultures of heterotrophic microorganisms isolated from Baikal. Conditions limiting the microbial growth improve from the dilution of 1 : 0 to the dilution of 1 : 5. The mean time of generation is 27 hours for June--July. Generation time determined for pure cultures of heterotrophic microorganisms in the conditions similar to natural can be used to calculate production of the bacterial biomass for a definite period of the year.

The very high morbidity rates of Enteritis infectiosa diseases demand improved prophylactic measures. An important indication of the source of these illnesses is the fact that infections in private households are about three times more frequent than in canteens. Indeed, the rise in morbidity is undoubtedly caused by inadequate treatment of raw products, of meal rests and by insufficient heating processes. Furthermore, in household kitchens no efforts are made to interrupt infection chains, and disinfections are considered as superfluous and housewives are content if their kitchens appear to be clean. The aim of our study performed in a normal household kitchen, was to investigate cross-contamination caused by pathogens, introduced into the kitchen from outdoors. A further aim was to establish the main sources of contamination in order to be able to recommend practical disinfection procedures. The main fields of contamination discovered when 55 meals prepared were: a) working surfaces (including boards of wood and plastics) b) kitchen- and cutting-machines. The amount of test organisms (Sarcinae), introduced into the kitchen (unbeknown to the housewives) by experimentally contaminated minced meat was only reduced by common cleaning procedures, in sofar as nearly half of the original contaminations could be demonstrated to be still present. However, when the normal cleanser was replaced by one containing hypochlorite, and with retention of the same working routines, about 90% bacteriologically clean surfaces were determined. In this way it could be demonstrated that infection chains can be interrupted. It is, however, not correct to compare the efficiency of these procedures with the efficiency of disinfection, according to the Federal Infectious Diseases Act (Bundesseuchengesetz). On practical application of these experiences it must be borne in mind that housewives should not be forced to apply medical disinfection procedures: indeed, traditional and practised cleaning methods should be retained, as far as possible. We recommend therefore that manufacturers supply household cleansers with an anti-bacterial additive, after its application in the kitchens working surfaces and machines are bacteriologically clean. Additionally housewives should be appropriately informed about the necessity of these manipulations. We consider minimization of toxicity and a thorough environmental compatibility of formulations to be self-evident.

The results of epidemiological investigations justifies the assumption that increasing health defects, especially enteritis infectiosa, are caused inter alia by inadequate hygienic conditions in households. The number of such diseases ranges between 100,000 and more than 1,000,000 cases per year in the FRG. Responsible for this development is a lack of information about the behaviour of microorganisms in the environment and its pathways of distribution. In addition risks are growing with the recommendation of cleansing methods, which had been adequate for the kitchen techniques in former centuries, but must fall under the conditions of the modern supply, processing and conservation. The described investigations are directed at the determination of the distribution of germs by working in normal household kitchens and at the effectiveness of surface-decontamination-cleansers (so-called FD-preparations). Test principle was the production of a complete dinner by each of 79 housewives with use of minced meat, which was contaminated with micrococcus luteus. After final cleaning of the kitchen we determined the degree of contamination of surfaces, machines and of the components of the meal with use of rodacplates, swabs and quantitative cultures respectively. The experiments are completed by interviews with the housewives. The results let conclude that the use of household cleansers with germicidal properties even in the hand of housewives will reduce the distribution of unwanted microorganisms in the kitchens. In this respect surfaces, on which components of the meal are prepared, and the machines, like cutting machines, waring blenders a.o., are of utmost importance. Disinfections of other parts of the flats including toilets are unnecessary (exception: severe infectious diseases). Therefore the use of FD-preparations outside of the kitchens is not required, but acceptable (it is not necessary to use a cleanser in the kitchen, another one in the toilet and a third one for the bath tube etc.). We do not recommend adapting cleaning and disinfective methods of the hospitals to the normal households. Instead of medical disinfections one should use detergents with nontoxic germicidal additives (e.g. H2O2) in this area, which do not require changing the traditional cleaning techniques. They also should guarantee that cleanliness, absence of odor and minimization of germs are achieved. In addition normal kitchen soaps should be replaced by HD-preparations.

Experimental study of the space environment effect on living organisms is one of the most important tasks of exobiology. However location of the living organisms under study outside space vehicles and sputniks is combined with technical difficulties. Therefore it is much more suitable to reproduce conditions found in space in laboratory and to study its effect on living cells. It was proved that low temperatures, even those approaching absolute zero do not kill microorganisms. The fact of microorganisms surviving radiation of some million roentgen suggests that they would not be killed by ionizing radiation in space. UV rays should be considered as the most active sterilizing agent. The ability of microorganisms to resist high vacuum is studied much worse. Under the action of high vacuum at 10(-8)-10(-9) mm Hg during 72 hours all studied seven species of spore-forming bacilli remained viable. As for nonsporeforming bacteria under conditions mentioned, cells of some species perished (correction of parished) completely while other species retained viable cells. Conidia of fungi and parts of mycelium of fungi which do not form conidia, sustained high vacuum well.

It has been known that the extracellular proteinase of Coccus P is found only in cultures grown in the presence of Ca(2+). It is now shown that this cation is required neither for synthesis, excretion, or activation of a zymogen nor as a prosthetic factor necessary for enzymatic activity. The only function of Ca(2+) is to stabilize the active structure of the enzyme molecule, presumably by substituting for absence of S-S bridges. In the absence of Ca(2+), the excreted proteinase undergoes rapid autodigestion and, instead of the active protein, its hydrolytic products are accumulated in the culture fluid. In minimal medium and under conditions of enzyme stability [presence of Ca(2+) and Ficoll (Pharmacia)], Coccus P accumulates the proteinase at a gradually reduced speed although the rate of cultural growth remains constant. It is shown that this decline in rate of accumulation is caused by the excreted proteinase itself, possibly acting on its own precursor emerging from the cell in a form susceptible to proteolytic attack and not amenable to Ca(2+) protection. A proteinase precursor is actually demonstrable in a calciumless culture at the onset of the enzyme accumulation which follows Ca(2+) addition. It is suggested that excreted proteins require an unfolded (or incompletely folded) structure to cross the cell envelope.