- Volume 129, Issue 3, 1983
Volume 129, Issue 3, 1983
- Pathogenicity And Medical Microbiology
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Analysis of Polypeptides of Mutants of Mycoplasma pneumoniae that Lack the Ability to Haemadsorb
More LessHaemadsorption-negative mutants of Mycoplasma pneumoniae were isolated which varied in their capacity to adsorb erythrocytes of various animal species suggesting adherence to erythrocytes is mediated by different binding mechanisms. Trypsin treatment of the wild-type strain resulted in loss of haemadsorbing activity; several polypeptides, some of which regenerated with haemadsorbing activity following further incubation, were also trypsin sensitive. The haemadsorption-negative mutants could be divided into two groups according to their polypeptide pattern. In the first group (11 mutants) the PAGE pattern was identical to that of the wild-type strain. The second group comprised 7 mutants which differed from the wild-type by lack of one or more polypeptides with molecular weights of 190000, 90000 or 40000. During growth attachment to glass was weak or absent in the mutants. Surface hydrophobicity as measured by hydrophobic-interaction chromatography was nearly comparable in mutants and parent strain.
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Antibody Responses to Antigens of Streptococcus mutans in Monkeys (Macaca fascicularis) Immunized against Dental Caries
More LessImmunization of rabbits or monkeys with walls prepared from Streptococcus mutans by a procedure including extraction with SDS at room-temperature induced antibodies to three antigens (A, B and C) detectable by crossed Immunoelectrophoresis. Antigens A and B have previously been characterized as proteins of molecular weight 29000 and 190000, respectively. Antigen C was characterized as having a molecular weight of 70000 and was purified by immunosorbent affinity chromatography and hydrophobic interaction chromatography. Another wall protein, antigen D, of molecular weight 13000, was extracted from walls with Triton X-100. Immunization of monkeys with walls prepared from cultures of S. mutans grown at a high (D = 0.5 h−1) or low (D = 0.05 h−1) dilution rate in a chemostat showed that only the latter induced protection against dental caries. There was a positive correlation between levels of antibody to antigens A and C and induction of protection and a negative correlation between protection and the level of antibody to antigen B. No antibody to antigen D was detected in protected monkeys and an experiment in which monkeys were immunized with pure antigen D confirmed that it does not induce protection.
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- Physiology And Growth
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The Effects Of Methanol, Ethanol, Propanol and Butanol On Bacterial Attachment To Surfaces
More LessThe effects of methanol, ethanol, propanol and butanol, at concentrations of 0·2, 0·5, 1·0, 1·5 and 2·0 % (v/v), on the attachment of a marine Pseudomonas sp. to polystyrene dishes (PD) and tissue culture dishes (TCD) were determined. When the bacteria attached in the presence of the alcohols, attachment to TCD was increased with certain concentrations of ethanol (0·2 and 0·5 %), propanol (0·2, 1·5 and 2·0 %) and butanol (1·0 %), with either a decrease in attachment or no effect with the other concentrations tested. With PD, there was no increase in attachment, but the relationship between numbers of attached bacteria and alcohol concentration paralleled that obtained with TCD. Pre-incubation of the bacteria with the alcohols affected their subsequent attachment, but the resultant increases or decreases in attachment were not consistent with those obtained when attachment occurred in the presence of alcohols. Physicochemical properties of the attachment system were evaluated by measuring liquid Surface tensions (γLV) and sessile drop (θSD) and air bubble (θB) contact angles on TCD and PD of the bacterial suspending medium with the various alcohol concentrations, both before and after incubation with the alcohols. There was a relationship between numbers of attached bacteria and medium γLV, with minimum attachment occurring at γLV, values of 64-69 mN m−1. The increase in attachment to TCD in the presence of ethanol, propanol and butanol was accompanied by an increase in respiration rate, which could reflect a modification of cell surface components.
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Growth Of Streptococcus Pyogenes and Streptolysin O Production In Complex and Synthetic Media
More LessA comparative study of the growth of a highly haemolytic group A streptococcal strain in Trypticase-yeast extract medium and in a chemically defined medium was undertaken. Appreciable growth was obtained in the latter medium with the release of significant amounts (120 haemolytic units) of streptolysin O. This indicates that toxinogenic factors present only in the peptones of complex media are not essential for biosynthesis and release of this cytolytic toxin, as is the case for many bacterial toxins. NADase was also released in the synthetic medium. Bacterial cell mass, growth rate, and streptolysin O production were threefold higher in the complex medium. The effects of various carbohydrates on streptolysin O production in complex medium are investigated. No repression of toxin formation by glucose was observed. The relationship between growth and toxinogenesis in streptococci and in other toxinogenic bacteria is discussed.
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The Role Of Limited Respiration In The Incomplete Oxidation Of Glucose By Saccharomyces Cerevisiae
More LessThe respiratory capacity of Saccharomyces cerevisiae growing in continuous culture on glucose and on mixtures of glucose and ethanol was investigated. An oxygen uptake rate of 8 mmo1 g−1 h−1 was found to limit the ability of the organism to degrade a substrate purely oxidatively. On glucose as sole energy and carbon source, this respiration rate was invariably achieved at an identical growth rate and thus at an identical substrate uptake rate when the inlet glucose concentration was varied. The rate of ethanol co-consumption together with glucose was strictly governed by this limiting maximum respiratory capacity and no repression of respiration was observed at dilution rates where ethanol was excreted by the cells. Hence, a limitation in some step in the oxidative branch of catabolism is likely to be responsible for incomplete oxidation of glucose at high growth rates rather than an undefined action of glucose repression.
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Modifications of Cell-wall Polysaccharides during Stipe Elongation in the Basidiomycete Coprinus cinereus
More LessModifications of cell-wall polysaccharides during stipe elongation in Coprinus cinereus were investigated by gel-filtration and Smith-degradation analyses. During stipe elongation two polysaccharide fractions (I and IVa) decreased in average molecular weight, whereas two other fractions (II and III) increased marginally in molecular weight. The decreases in molecular weight of the former fractions were accompanied by changes in glycosidic linkage composition. Glucans comprised the bulk of all fractions; additionally there was an appreciable contribution from mannose and xylose in fraction II. The results are discussed in relation to the mechanisms of stipe elongation.
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The Utilization of Nitriles and Amides by Nocardia rhodochrous
More LessNocardia rhodochrous LL100-21 grew on acetonitrile, acetamide, a range of aliphatic nitriles and amides, benzonitrile and benzamide as the sources of carbon and/or nitrogen. It also grew on acetate, several other aliphatic acids, and benzoate as carbon sources. Growth on either acetonitrile or acetamide resulted in induction of both acetonitrilase and acetamidase activities, which were shown to be due to separate enzymes. Growth on benzonitrile resulted in the ability to release ammonia from benzonitrile but not benzamide, acetonitrile or acetamide. Growth on benzamide resulted in the ability to form ammonia from benzamide but not benzonitrile, acetonitrile or acetamide. Measurements of respiratory activity of the bacteria grown on the various substrates showed a similar pattern of induction of oxidative activity for these compounds.
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Glucose-induced Trehalase Activation and Trehalose Mobilization during Early Germination of Phycomyces blakesleeanus Spores
More LessWhen dormant spores of Phycomyces blakesleeanus were activated without concomitant activation of trehalase, breakdown of storage trehalose during early germination was not prevented. Measurement of trehalase activity during early germination of spores activated in this way indicated a subsequent rapid activation of trehalase upon incubation of the spores in germination medium. Trehalase activity reached a maximum after about 10 min of germination; thereafter it declined to values somewhat higher than those found in dormant spores. The same was observed when the activation of trehalase which normally occurs during heat activation of the spores was suppressed by adding long-chain alcohols to the activation medium. These results argue against previous speculation that trehalase is a 73 ‘luxury’ molecule in the spores and that its activation has no significant role in the induction of germination. They point, on the other hand, to an important role for trehalase in the induction of germination. The main factor in the germination medium responsible for the activation of trehalase was found to be glucose. When spores were incubated under conditions in which they reverted to the dormant state, this subsequent trehalase activation was not seen. The increase in trehalase activity was not dependent on protein synthesis. A less pronounced increase was seen with glucose analogues. In the presence of azide the activation was only retarded, whereas in the presence of azide and salicylhydroxamic acid strong inhibition of trehalase activation was observed.
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Isopropyl-Substituted Phenols Have A Different Effect From Other Phenols On The Breaking Of Dormancy By Heat Shock In Phycomyces Blakesleeanus Spores
More LessPhenols are able to lower the temperature of heat activation (breaking of dormancy by heat shock) in Phycomyces blakesleeanus spores. The effect was observed with a series of phenols ranging, according to increasing lipophilic character, from unsubstituted phenol to 2,4-dichlorophenol. However, the concentration required to produce the same effect with each phenol was reduced with increasing apolar character. A linear relationship was obtained between the log of the concentration of each phenol needed to produce a 4 °C shift of the half-activation temperature and the log of its octanol/water partition coefficient. In contrast, the isopropyl-substituted phenols thymol, 2- and 4-isopropylphenol and 3-isopropylcatechol all raised the half-activation temperature of the spores. The same effect was observed with menthol, the unsaturated analogue of thymol. The heat resistance of the spores was lowered by all phenols, including isopropyl-substituted phenols. Although the reason for the anomalous behaviour of isopropyl-substituted phenols is not known, the opposite effect on spore heat activation and spore heat resistance indicates that the activation process of the spores is not linked to the process of spore killing. Therefore, spore activation is not due to some kind of non-specific sublethal protein denaturation, as might have been concluded previously from the fact that many spore activation methods are sublethal treatments.
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Mineral Ion-containing Vacuolar Inclusion Bodies Associated with Ca2+ Deficiency in Oogonia of Saprolegnia diclina and S. terrestris
More LessThe frequency of occurrence of electron-dense vacuolar inclusions in oogonia of Saprolegnia diclina and S. terrestris was significantly greater under Ca2+-deficient culture conditions than under Ca2+-sufficient conditions. Bodies similar to inclusions seen in sections of oogonia were present in debris from living cultures ground up in de-ionized water. Energy dispersive X-ray analysis of inclusions in sections showed the presence of Mg, P, Ca, and Mn in both species and Na, S and Zn in S. diclina. The bodies from ground cultures contained Mg, P, Mn and Zn in both species and Na in S. terrestris.
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Non-coordinate Regulation of Rhizobium Nitrogenase Synthesis by Oxygen: Studies with Bacteroids from Nodulated Lupinus angustifolius
More LessExperimental conditions which allowed liquid suspensions of lupin bacteroids (Rhizobium NZP 2257) to reduce acetylene at high rates were established. At a dissolved oxygen concentration of 2 μm, swirled suspensions of the bacteroids reduced acetylene at a linear rate of 23 ± 5 nmol (mg cell protein)−1 min−1. The kinetics of protein synthesis were measured by pulse labelling with [35S]methionine followed by two-dimensional electrophoretic analysis of cell lysates. When the suspensions were suddenly exposed to air, the rate of synthesis of the two nitrogenase components declined differentially. The decline in the rate of synthesis of the Fe-protein polypeptides resembled that observed for all the nitrogenase polypeptides in Klebsiella pneumoniae ( Eady et al., 1978 ); the rate of synthesis of the MoFe-protein polypeptides, however, showed a much slower decline. Several models are proposed to account for these results.
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Peptidoglycan-degrading Enzymes in Ether-treated Cells of Neisseria gonorrhoeae
More LessThe incubation of peptidoglycan fragments with ether-treated cells of Neisseria gonorrhoeae resulted in breakdown products that showed the presence of previously undescribed lytic enzymes. The properties of an endopeptidase able to hydrolyse peptide-linked bis-disaccharide peptide dimer to monomer units were examined. An exo-N-acetyl-glucosaminidase was also shown to release free N-acetylglucosamine. The breakdown pattern of glycosidically-linked dimer indicated the existence of an endo-N-acetylglucosaminidase. The activities of the latter enzyme and of the endopeptidase were both sensitive to βlactam antibiotics.
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- Short Communication
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Degrees of O-Acetylation and Cross-linking of the Peptidoglycan of Neisseria gonorrhoeae during Growth
More LessThe progress of incorporation of radioactive glucosamine into the O-acetylated and non-O-acetylated sub-units of the insoluble peptidoglycan of growing Neisseria gonorrhoeae was examined. More than 80% of the final degree of cross-linking was achieved within 3 min; the remainder of the process took much longer. Rapid O-acetylation occupied up to 10 min, at which time only about 65% of the maximum value had been reached. There was thus evidence for maturation of peptidoglycan both in regard to cross-linking and to O-acetylation.
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Mycolic Acid Patterns of Four Vaccine Strains of Mycobacterium bovis BCG
Thin-layer chromatography of methanolysates of four widely used vaccine strains of Mycobacterium bovis BCG showed that only one organism had the expected pattern of mycolic acid methyl esters characteristic of Mycobacterium bovis and Mycobacterium tuberculosis. The remaining three BCG strains lacked methoxy mycolic acid.
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- Taxonomy
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Differentiation between Gram-negative Anaerobic Bacteria by Pyrolysis Gas Chromatography of Lipopolysaccharides
More LessLipopolysaccharides extracted by phenol-water from nine strains of Gram-positive anaerobic bacteria (Bacteroides, Fusobacterium and Veillonella), have been examined by means of pyrolysis gas chromatography. Lipopolysaccharides were fragmented into a group of low molecular weight components and four characteristic high molecular fractions probably consisting of hydrocarbons from the lipid part of the material. The latter fractions were specific for each of the genera tested. At the species level characteristic differences were also found although a limited number of strains were tested. Due to the high reproducibility of the technique, the potential of using the method in differentiating Gram-negative anaerobic bacteria was indicated.
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Numerical Taxonomy of Streptococcus
More LessA numerical taxonomic study of strains of Streptococcus, together with representatives of allied genera, showed 28 reasonably distinct phenons. The major areas, with their phenons, were: (a) enterococcal species group (S. faecalis, S. faecium, ‘S. avium’ and a proposed new species ‘S. gallinarum’); (b) paraviridans species group (S. bovis, S. equinus, S. salivarius, ‘S. casseliflavus’, S. mutans, S. raffinolactis and an unidentified Oral Group I); (c) lactic species group (S. lactis including S. cremoris); (d) thermophilic species group (S. thermophilus); (e) viridans species group (S. mitis, S. sanguis, a proposed new species ‘S. oralis’ and ‘S. milleri’); (f) pyogenic species group (S. agalactiae, S. pyogenes, S. equi, ‘S. equisimilis’ including ‘S. zooepidemicus’, and a cluster of Lancefield Group B strains of human origin); (g) parapyogenic species group (S. uberis, ‘S. dysgalactiae’, and a cluster of strains of Lancefield Groups R, S and T). Species of Aerococcus, Gemella, Leuconostoc and Pediococcus are very closely related to the streptococci.
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Numerical Classification Of Mycobacterium Farcinogenes, Mycobacterium Senegalense and Related Taxa
More LessSixteen strains designated Mycobacterium farcinogenes, fifteen Mycobacterium senegalense, and ten Nocardia farcinica were, together with strains of Mycobacterium and Nocardia, subjected to numerical phenetic analyses using 96 unit characters. The data were examined using the simple matching (S sm), Jaccard (S J) and pattern (D P) coefficients and clustering achieved using the unweighted average linkage algorithm. Cluster composition was not markedly affected by the coefficient used or by test error, estimated at 2.5%. The N. farcinica strains formed a distinct and homogeneous cluster in an aggregate taxon corresponding to the genus Nocardia. The M. farcinogenes and M. senegalense strains were recovered in well-defined and homogeneous phena within the genus Mycobacterium. Mycobacterium senegalense consistently showed a high overall similarity with clusters equated with M. chelonei and M. fortuitum, while the M. farcinogenes cluster was not closely associated with any of the mycobacterial clusters. The results are discussed in the light of other developments in the taxonomy of the bovine farcy bacteria.
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Immunodiffusion Analyses of Mycobacterium farcinogenes, Mycobacterium senegalense and Some Other Mycobacteria
More LessThirty-one strains of Mycobacterium farcinogenes and M. senegalense were analysed together with twenty-five strains representing ten mycobacterial species. The comparative immunodiffusion technique was employed, using two reference systems, one for M. farcinogenes and the other for M. senegalense. The results indicate that the slow growing M. farcinogenes and the fast growing M. senegalense strains are closely related and can not be separated into two clearly distinct clusters. Both species were closely related to M. fortuitum, including strains designated ‘M. peregrinum’ but clearly different from other tested mycobacterial species. The serological data are consistent with the classification of M. farcinogenes and M. senegalense, and possibly M. fortuitum, in a single species. The results are discussed within the context of other taxonomic analyses of M. farcinogenes and M. senegalense.
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- Corrigenda
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