Search PubMed⌕ Search

Biomedical subjects

M Kilian

Publications and source records attributed to M Kilian.

At least 163 records · Page 9Linked to original sources
PubMed1978

Rapid identification of Actinomycetaceae and related bacteria.

Identification of new isolates belonging to the family Actinomycetaceae requires extensive numbers of biochemical tests, supplemented with gas-liquid chromatography determination of fermentation end products and, often, analysis of cell wall composition. This paper describes the results of the testing of 162 strains of Actinomycetaceae and related taxa for 20 different enzymatic activities including phosphatases, esterases, aminopeptidases, and glycosidases. The results of all tests were read after 4 h of incubation. The results obtained in the study provide significant new information on the biochemical properties of these groups of bacteria. An identification scheme based upon 13 selected tests, which allow the identification of these groups of bacteria within 4 h, is proposed.

Actinomycetaceae↗
PubMed1977

The effect of chlorhexidine and some other detergents on the activity of dextransucrase from Streptococcus mutans.

The inhibitory effect of chlorhexidine and other bis-biguanides on the formation of dental plaque is not fully understood. The present paper describes the effect of chlorhexidine and some selected detergents on the activity of dextransucrase (EC 2.4.1.5.), an enzyme involved in the formation of important components of dental plaque. All detergents examined exerted an inhibitory effect on dextransucrase activity, to some degree dependent on the presence of charged groups and their characters. The high concentrations of chlorhexidine necessary to inhibit dextransucrase activity seem to exclude the possibility that chlorhexidine exerts its plaque inhibiting effect by means of an effect on dextransucrase.

Biguanides↗
PubMed1976

A taxonomic study of the genus Haemophilus, with the proposal of a new species.

A collection of 426 Haemophilus strains isolated from people with infectious diseases and from the normal flora of mucous membranes in humans and various animal species was studied in an attempt to revise and improve the taxonomy of the genus Haemophilus. The examinations included the determination of a number of biochemical and physiological properties, of which several had not previously been applied to the taxonomy of haemophili. The resulting data reavealed many hitherto unrecognized characters of taxonomic significance and several of the species can now be more accurately defined. The classification presented is supported by the DNA base composition of a large number of representative strains. A diagnostic key to the different taxa is presented. Haemophilus influenzae and H. parainfluenzae have been subdivided into a number of biotypes. It is possible to demonstrate a relationship between the individual biotypes of H. influenzae and the origin of the strains assigned to them. The results indicate that H. aegyptius, H. parahaemolyticus and H. paraphrohaemolyticus do not merit specific status. Four unnamed taxa of V-factor-dependent haemophili have been recognized. The name Haemophilus segnis is proposed for one of these taxa, which consists mainly of strains isolated from the human oral cavity. It is demonstrated that the name H. Ducreyi has been used for different groups of bacteria, and that only one of these groups can legitimately be assigned to the genus Haemophilus. Haemolytic V-factor-dependent strains from swine, previously included in H. parahaemolyticus, are significantly different from strains of human origin and should be named H. pleuropneumoniae. None of the strains from swine and fowls were haemin-dependent. The relationships of these strains to the species H. suis and H. gallinarum, and to H. parasuis and H. paragallinarum are discussed. Haemophilus piscium is shown not to belong to the genus Haemophilus. The taxonomic position of H. aphrophilus is uncertain and its possible relationship to Actinobacillus actinomycetemcomitans requires further study. The positive correlation found between the ecology of the strains studied and their affiliation with the different taxa is discussed.

Animals↗
PubMed1976

Haemophili in developing dental plaque.

Evidence for a possible role played by oral haemophili in the development of dental plaque was sought by studying the occurrence of these bacteria in early dental plaque of smooth surfaces and occlusal fissures in six dental students. The mean number of haemophili per 10(3) anaerobes in early smooth surface plaque (18 h) and fissure plaque (7 d) was 95 and 22 respectively. Examination of 988 Haemophilus isolates revealed that H. parainfluenzae was the only species in samples of fissure plaque, whereas some samples from smooth surfaces, in addition to the predominating and ubiquitous H. parainfluenzae, yielded growth of the two species H. segnis and H. aphrophilus. It is concluded that haemophili are among the primary colonizers of smooth surfaces of teeth.

Dental Plaque↗
PubMed1976

The taxonomy of haemophili isolated from conjunctivae.

The paper provides a description of 112 Haemophilus strains isolated from cases of conjunctivitis in Egypt, Tunisia, Denmark, and the U.S.A., and aims at a clarification of the taxonomy of haemophili implicated in conjunctivitis. Although the study confirms the diversity of haemophili which can be isolated from inflamed conjunctivae, the vast majority of strains could be assigned to either biotype II or III of H. influenzae. Thirteen strains possessed all the characteristics of the Koch-Weeks bacillus. However, judged by the findings the recognition of the Koch-Weeks bacillus as a separate species does not seem tenable. It is suggested that this organism is considered a haemagglutinating variety of H. influenzae biotype III. The study indicates that the haemagglutinating ability per se, which can be found in strains of several taxa of Haemophilus, is associated with a special pathogenic potential.

Child, Preschool↗
PubMed1976

Rapid diagnosis of Enterobacteriaceae. I. Detection of bacterial glycosidases.

The paper describes a number of tests for the rapid detection of glycosidases including alpha-glucosidase, beta-glucosidase, beta-glucuronidase, beta-xylosidase and alpha-fucosidase. The methods use heavy suspensions of viable but non-multiplying bacteria in a buffered solution of a chromogenic substrate. The results of the tests are readable within 4 h. The application of these tests to a collection of 633 strains of Enterobacteriaceae and Vibrionaceae demonstrates that some of the tests may be valuable additions to the present tests available for the identification of bacteria belonging to these families. beta-glucuronidase activity was observed only in strains of the Escherichia-Shigella group. 97 per cent of the Escherichia strains possessed beta-glucuronidase activity. beta-xylosidase activity was almost completely restricted to strains of the Klebsiella-Enterobacter group in addition to Yersinia strains. None of the strains possessed alpha-fucosidase activity.

Bacteriological Techniques↗
PubMed1976

The haemolytic activity of Haemophilus species.

The importance of the species of blood employed for detection of haemolysis in seventy-seven Haemophilus strains of human and porcine origin was studied. Significant differences in the visibility of haemolytic zones obtained on the different blood agar media were observed. In decreasing order, the suitability of the species of blood was: calf, sheep, human, rabbit, poultry and horse blood. On plates containing washed sheep or calf red cells the haemolysin of all 36 strains of Haemophilus pleuropneumoniae acted synergistically with the beta-toxin of the Staphylococcus aureus strain used as "feeder strain", giving rise to a lytic phenomenon resembling the CAMP reaction.

Culture Media↗
PubMed1976

Initial colonization of teeth in monkeys as related to diet.

The initial phases of plaque development on nonretentive tooth surfaces were studied bacteriologically in Macaca irus monkeys fed by stomach tube and provided with various oral supplements. Except for the oral implantation of Streptococcus mutans in some of the animals, the oral flora was not changed prior to the studies. Dental plaque was allowed to develop on initially cleaned tooth surfaces for 3 to 5 h. Plaque samples were collected and cultured on a number of selective and nonselective agar media, and several hundred isolates from each sample were isolated and identified. The numerically predominant organisms in initial plaque were S. mutans, Streptococcus sanguis, and Actinomyces viscosus. Additional organisms regularly found, but usually in smaller numbers, were Streptococcus mitior and a group of fastidious gram-negative rods including Haemophilus species, Eikenella corrodens, and Actinobacillus actinomycetem-comitans. The colonization of S. mutans was dependent on sucrose and occurred at the expense of S. sanguis. In these experiments S. mutans accounted for 25 to 65% of the primary plaque formers. All other species encountered colonized the teeth irrespective of the diet. It is postulated that the early sucrose-dependent establishment of S. mutans directly on the enamel pellicle plays a key role in the development of a cariogenic plaque.

Actinomyces↗
PubMed1976

Haemophilus from the lower respiratory tract of patients with cystic fibrosis.

Fifty-six non-haemolytic Haemophilus strains were isolated during current bacteriological examinations from material from the lower respiratory tract of 39 patients with cystic fibrosis during a 6-month period. Except for six strains which belonged to Haemophilus parainfluenzae, all strains were identified as Haemophilus influenzae. Biotype I of H. influenzae was the predominating taxon (38%) and was especially related to patients with recurrent or prolonged colonization. Only two strains were capsulated. An unexpectedly high percentage of the strains produced lysine decarboxylase. The significance of this property in the pathogenesis of the respiratory tract colonization is discussed.

Adolescent↗