摘要:

The initial adhesion of cells in synchronized and steady state cell cultures has been investigated, and was found to be of a constant value through all stages of the cell cycle. This is contrary to observations on established cell adhesion in monolayer cell cultures where adhesion is decreased during mitosis. It is suggested that this decrease in cell adhesion is caused by a reduced contact area between the mitotic cell and the substratum.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Five strains ofMoraxella boviswere studied and found to yield distinct colony types with respect to agar corrosion and formation of corroding spreading zones. The types were largely similar to those ofM. kingii, although some morphological differences were observed. Distinctly corroding clones, with more or less pronounced spreading colonies (SC type), were isolated from all strains. These isolates were all strongly fimbriated, as observed by electron microscopy. The fimbriae had a diameter of 65–85 Å. Another colony form, without corrosion and spreading (N type), was also observed in all strains. Electron microscopical preparations from these colonies revealed no fimbriae, or only occasional fimbriae, possibly of slightly different appearance, could be detected. With varying frequency, from none observed to about one in 10,000 colonies, N type populations revealed the intracolonial occurrence of fimbriated SC variants by partial change of colony morphology after a few days of incubation. Spontaneous variation from SC to N, accompanied by loss of fimbriation, was also observed. When 12–30 hr old SC colonies were subcultivated, less than one in 10,000 progeny colonies were usually observed to be of the N type, whereas older colonies sometimes revealed a high percentage of N variants in the progeny. A colony type intermediate between N and SC (NSC type) was occasionally seen, with relatively weak agar corrosion and spreading, and with an apparently slightly reduced degree of fimbriation, as compared with the SC type. The intermediate phenotype was unstable, however, showing an irregular tendency to produce progeny of a more corroding and spreading morphology. Two reference strains (including the neotype) ofM. nonliquefacienswere studied and revealed fimbriae‐associated colony type differentiation slightly different from previously examined strains of this species and fromM.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00189.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

In four out of fiveMoraxella kingiistrains examined, strongly corroding and usually spreading colony forms (named SC type) could be isolated, as well as non‐spreading and non‐corroding or weakly corroding forms (N colony type). Electron microscopical preparations made from SC colonies always contained numerous fimbriae, whereas usually no fimbriae could be detected in preparations made from cultures of the N type. In the case of weakly corroding forms, a few fimbriae could be observed in some preparations, their occurrence apparently corresponding in time with the slowly developing corrosion. The fimbriae ofM. kingiiwere of the same approximate dimensions (60–85 Å) as observed for spreading‐corroding colony variants ofM. nonliquefaciensandM. bovis.In one strain, low‐frequent spontaneous variation from the N to SC type was observed, with a corresponding gain of fimbriation. Spontaneous variation in the other direction, from SC to N, accompanied by loss of fimbriation, was also seen in this strain. The latter variation was probably also always of a low frequency. When it had occurred, the N variant cells easily outnumbered the SC type in mix

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00190.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Non‐fimbriated or weakly fimbriated cells from non‐corroding colonies (N type) and strongly fimbriated cells from agar‐corroding and often spreading colonies (SC or NSC types) of the bacterial speciesMoraxella nonliquefaciens, M. bovisandM. kingiiwere found to differ very distinctly when used as recipients in streptomycin resistance transformation. N type isolates of these species were always found to be deficient in competence, being either non‐transformable or weakly responding when exposed to autologous or homologous DNA extracted from streptomycin resistant mutants of N cells. Corresponding SC or NSC type isolates revealed much higher T/E (transformants/colony‐forming recipient units) ratios when exposed to the same N type DNA preparations (T/E = 10‐3to 10‐2or above in 11 strains, 10‐4to 10‐5in three strains; short‐term (20 min) DNA exposure). These values are from about 400 times to more than 106times higher than the N type T/E ratios in individual strains. In the three strains with low SC or NSC T/E ratios, the corresponding N forms were either transformable by long‐term DNA exposure only or completely non‐transformable by any method. By using a modification of the long‐term DNA exposure technique for screening of competence on more than 14,000 single colonies, no spontaneous change of competence independent of variation in colony type and fimbriation could be detected in any direction, except for one single observation of genetically stable change from low‐level competence to incompetence in an N type variant. It is briefly discussed whether fimbriae could play a hitherto unknown active role as an important competence factor, or whether the cellular appendages may be functionally inert in this respect, only reflecting the presence of

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00191.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Gas‐liquid chromatography (GLC) of trifluoroacetylated (TFA) whole cell methanolysates as a procedure for obtaining species specific GLC elution profiles has been introduced. This method and a modification of the previously described trimethylsilyl (TMS) derivatization used for identical purpose were tested on four strains belonging to the bacterial speciesNeisseria catarrhalis, N. ovisandN. meningitidis.The TFA and TMS elution profiles are compared, and their usefulness in characterization of strains and species in relation to the best reproducibility obtainable is discussed. The TFA method gives better resolved and more reproducible elution profiles. The method appears to have a high potential as an aid in bacterial classification and identificatio

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00192.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Twentyfive strains or substrains belonging to the bacterial speciesMoraxella nonliquefaciens, M. bovis, M. kingii, M. osloensis, M. phenylpyrouvicaandM. urethralis(tentative designation) were examined by gas‐liquid chromatography (GLC) of whole cell methanolysates. Each strain gave a reproducible chromatogram, usually with no difference between non‐fimbriated and fimbriated variants. With a few exceptions, there was no significant difference between the elution profiles of strains belonging to the same species. The study revealed similarities as well as distinct dissimilarities in interspecies comparisons. When compared withM. bovis, the speciesM. nonliquefaciensandM. phenylpyrouvicashowed most similarity, whereasM. kingiirevealed the greatest chromatographic deviation. The remaining two species were intermediate in this respect. The results are discussed in relation to taxonomic data previously arrived at by other methods, in particular measurements of nucleic acid homologies and heterologies. Generally, the two groups of results were consistent, and it is concluded that GLC is a valuable tool for evaluation of relationship between species, adding significantly to the reliability of species allocation to genus. GLC appears also applicable for species identification of isolates of moraxellae and similar organisms. However, the sometimes great similarities between closely related species and the occasionally observed (minor) intraspecies variations in elution profile substantiate the need for supplementary meth

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00193.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Fourteen strains of altogether eight species of neisseriae were “fingerprinted” by gas‐liquid chromatographic (GLC) analysis of their trifluoroacetyl derivatized whole cell methano‐lysates. The elution profiles were compared with each other and with those of previously analysedMoraxellaspecies. The chromatograms of “false neisseriae” (Neisseria catarrhalis, N. ovisandN. caviae) and of cocci belonging to “true neisseriae” (N. cinerea, N. flavescens, N. meningitidisandN. gonorrhoeaeexamined) formed two relatively homogeneous groups distinctly different from each other. The “false neisseriae” group showed a striking chromatographic resemblance to most species of the present genusMoraxella.TheM. kingiiprofile, however, differing from other moraxellae, also differed from both groups of neisseriae. The recently described rodshapedNeisseria elongatarevealed, as expected from nucleic acid compatibility tests, a chromatographic pattern almost completely identical to those of other “true neisseriae” species. The results therefore confirm previous conclusions on group relations in Neisseriaceae base

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00194.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Cultivation of S. aureus in the presence of 0.03 IU benzyl‐penicillin stimulated the formation of a haemolysin which was suggested to be alpha‐lysin. Its molecular weight was estimated to be 30000 by molecular sieve chromatography. It was mainly active on rabbit erythrocytes and was neutralized by alphalysin antibody. Furthermore it gave a reaction of identity in comparative immunoelectrophoresis with an are which was shown to represent alpha‐

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00195.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Intracerebral infection of mice with different herpes simplex virus (HSV) strains caused raised dopamine and 5‐hydroxytryptamine turnover, reflected in increased brain concentrations of the acid metabolites of the aminesi. e.homovanillic acid (HVA) and 5‐hydroxyindole‐acetic acid (5‐HIAA). Inhibitors of virus multiplication (actinomycin D, mitomycin C and iododeoxyuridine) and different variants of HSV were used to study whether the rise in mono‐amine metabolism was an event dependent upon the direct action of the virus or viral metabolites on pathways of mono‐amine synthesis. The results obtained were not compatible with such a hypothesis. The histopathological study of the distribution of the neuronal lesions indicated that the lower brain stem from which most of the monoaminergic neurons originate was hardly affected at all. The degree of severity of the neuronal lesions in relation to the HVA and 5‐HIAA concentrations found in infected brains was studied for 13 different HSV variants. The more extensive and frequent the lesions, the higher were the levels of the acids encountered. It was assumed that impaired functions of postsynaptic cells or altered receptor‐functions possibly affecting regulatory feed‐back mechanisms could be responsible for the increased mo

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00196.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

The prevalence of protein A producing strains ofS. aureuswas found to vary. An increase in the proportion of weak protein A producers during the past decade was found to coincide with a shift in dominant phage types in Denmark. Within phage groups I and II the ability to form large amounts of protein A was shown to be correlated to a deficient haemolysin production. This correlation was also found for group III strains susceptible to phage 75 A. Among group III strains susceptible to phages within the complex 83A, 84, 85, 6557, 89 two subgroups were remarkable. The strains which were resistant to neomycin (antibiogram PSTEN) produced large amounts of protein A, whereas those which were resistant to methicillin (antibiograms PSTEM and PSTM) produced little or no protein A. Analysis of the present material revealed no demonstrable or suspected pathogenic properties of protein A.

ISSN:0365-5563    

DOI:10.1111/j.1699-0463.1972.tb00197.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY