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At least 19 recordsLinked to original sources
PubMed1979

Nutrition and growth of the moderately halophilic bacteria Micrococcus morrhuae K-17 and Micrococcus luteus K-15.

Chemically defined media have been developed for the growth of two moderately halophilic bacteria, Micrococcus morrhuae K-17 and Micrococcus luteus K-15. M. morrhuae K-17 grows well in a synthetic medium (SM-1) which contains a number of salts, 0.21 M KCl, 2 M NaCl, D-mannose, five vitamins and ten amino acids. The synthetic medium (SM-2) for M. luteus K-15 contains a number of salts, 0.21 M KCl, 1 M NaCl, D-fructose, nine vitamins and nine amino acids. Nutritional studies show that M. morrhuae K-17 can utilize a large number of organic compounds as carbon and energy source while the ability of M. luteus K-15 in utilizing the organic compounds is rather limited. The minimum salt requirement is 0.5 M NaCl for both strains when growth at the optimum temperature of 30 degrees C. However, this requirement can be lowered to 0.2 M in M. luteus K-15 when grown at a lower temperature of 25 degrees C. It is concluded that the ability to grow in a wider range of salt concentrations in response to temperature is species specific in moderate halophiles. The salt range for growth to occur can be extended when cells of both strains are grown in complex medium which might provide the amino acids and growth factors that cannot be synthesized by these strains at high salt concentrations.

Amino Acids↗
PubMed1976

The fine structure of Micrococcus radiophilus and Micrococcus radioproteolyticus.

The radiation resistant bacteria Micrococcus radiophilus and M. radioproteolyticus were studied by thin sectioning and freez-etching techniques and the two species were found to be similar in the fine structure. The only significant difference was in the appearance of the surfaces of the cell walls in freeze-etched preparations. Since the two species, together with M. radiodurans, possess a unique cell wall structure and a cell wall peptidoglycan, which is different from that of other micrococci and Gram-positive cocci, it is recommended that they be reclassified into a new genus.

Cell Division↗
PubMed1976

Differentiation of Micrococcus luteus and Micrococcus varians on the basis of catalase isoenzymes.

Crude extracts prepared from four Micrococcus varians strains, 11 M. luteus strains and four laboratory isolates subsequently classified with M. luteus were assayed for catalase activity following electrophoresis on polyacrylamide gels. The enzyme patterns produced from the M. varians strains exhibited three catalase isoenzymes which were distinguished into two types of patterns depending upon the location of the major band. The extracts from all the M. luteus strains produced the same pattern, composed of two catalase isoenzymes of similar electrophoretic mobility. For both species the isoenzyme patterns agreed with the differentiation based on biochemical properties. The catalase activity activity staining method was shown to be a restricted yet reliable assay in the intrageneric but not intraspecies differentiation of yellow-pigmented micrococci.

Catalase↗
PubMed1981

A phylogenetic analysis of staphylococci, Peptococcus saccharolyticus and Micrococcus mucilaginosus.

The intra- and intergeneric relationships of the genus Staphylococcus, and the phylogenetic position of Peptococcus saccharolyticus and Micrococcus (Staphylococcus salivarius), were investigated by comparative oligonucleotide cataloguing of 16S rRNA. All the staphylococci investigated form a phylogenetically coherent group at the genus level that, in addition, contains the anaerobic species Peptococcus saccharolyticus. The genus Staphylococcus belongs to the broad Bacillus-Lactobacillus-Streptococcus cluster that is defined by Gram-positive bacteria with a low DNA G+C content. Micrococcus mucilaginosus is not a genuine member of the genus Micrococcus. The binary matching coefficients between the 16S rRNA of Micrococcus mucilaginosus and those representatives of the Arthrobacter/Micrococcus group and related genera indicate that Micrococcus mucilaginosus should be regarded as a member of a new genus.

Base Sequence↗
PubMed1987

Evaluation of a conventional routine method for identification of clinical isolates of coagulase-negative Staphylococcus and Micrococcus species. Comparison with API-Staph and API-Staph-Ident.

A collection of 138 consecutive isolates from blood primarily identified as Gram-positive, cluster-forming, coagulase-negative cocci was examined by a conventional routine method for identification of clinical isolates of coagulase-negative Staphylococcus and Micrococcus species. The method was based on selected reactions from the Kloos & Schleifer scheme, utilizing the conventional media of Statens Seruminstitut. Double determinations for each isolate were performed by the conventional method. The results were compared with speciation by the commercial micromethods API-Staph and API-Staph-Ident. For control, 31 Staphylococcus and 13 Micrococcus reference strains were included. Of the 31 Staphylococcus spp. (reference strains), the conventional system, API-Staph, and API-Staph-Ident correctly identified 87%, 87% and 81%, respectively. Micrococcus spp. were only identified to genus level by the conventional method as well as by API-Staph. API-Staph-Ident is not designed for Micrococcus identification. Of 138 blood isolates, 121 belonged to the genus Staphylococcus while 17 were Micrococcus spp. S. epidermidis dominated with all three methods, constituting approx. 35% of the isolates tested. In only 57% of the isolates identification by all three methods agreed. The three methods were unable to put a name on 7.5% (conventional method), 10.7% (API-Staph) and 2.5% (API-Staph-Ident) of the isolates. Reproducibility was high with the conventional method (100% for the reference strains and 91% for blood culture isolates) as well as with API-Staph and API-Staph-Ident (88%/81% and 81%/81%, respectively). We concluded that our conventional system was able to identify most clinically significant staphylococcal species by means of relatively few tests with a high certainty and a high degree of reproducibility.

Bacteriological Techniques↗
PubMed1988

DNA probes with different specificities from a cloned 23S rRNA gene of Micrococcus luteus.

A 7500 bp PstI restriction fragment of chromosomal DNA from Micrococcus luteus containing a 23S rRNA gene was cloned in vector pHE3 in E. coli RR 28 (the recombinant plasmid was designated pAR1). A recombinant phage (pAR5) hybridizing to all eubacteria tested was constructed by shotgun subcloning of the PstI fragment in phage M13mp8. Further subcloning of the fragments of the 23S rRNA gene in the vectors pTZ18R and pTZ19R using selected restriction sites of the gene enabled us to select cloned fragments of the 23S rRNA gene representing different specificities. Probes specific for Micrococcus luteus-Micrococcus lylae (pAR28), for the Arthrobacter-Micrococcus group (pAR27), for eubacteria (pAR5), and for the detection of eu- and archaebacteria (the so-called universal probe pAR17) were constructed. The specificity of each probe was analysed by dot hybridization to the chromosomal DNAs of representatives of most of the main phyla of eu- and archaebacteria.

Base Sequence↗
PubMed1975

Distribution and persistence of Staphylococcus and Micrococcus species and other aerobic bacteria on human skin.

The districution of Staphylococcus and Micrococcus species and associated coryneform bacteria, Acinetobacter, Klebsiella, Enterobacter, Bacillus, and Streptomyces on skin was determined during October 1971 from samples collected on persons living in North Carolina and New Jersey. Persistence of these organisms on skin was estimated in temporal studies conducted during the period from June 1971 to June 1972 on persons living in North Carolina. Staphylococci and coryneforms were the most predominant and persistent bacteria isolated from the nares and axillae. Staphylococci, coryneforms, micrococci, and Bacillus were the most predominant and persistent bacteria isolated from the head, legs, and arms. Acinetobacters were most frequently isolated during the warmer months of the years. Staphylococcus aureus and S. epidermidis were the most predominant and persistent staphylococci isolated from the nares, whereas S. epidermidis and S. hominis were the most predominant and persistent staphylocicci isolated from the axillae, head, legs, and arms. S. capitis was often isolated from the head and arms and S. haemolyticus was often isolated from the head, legs, and arms. S. simulans, S. xylosus, S. cohnii, S. saprophyticus, S. warneri, and an unclassified coagulase-positive species were only occasionally isolated from skin. Micrococcus luteus was the most predominant and persistent Micrococcus isolated from skin and preferred regions of the head, legs, and arms. M. varians was the second most frequent Micrococcus isolated. M. lylae, M. sedentarius, M. roseus, M. kristinae, and M. nishinomiyaensis were only occasionally isolated from skin. M. lylae was most frequently isolated during the colder months of the years.

Acinetobacter↗
PubMed1977

Comparative immunological study of catalases in the genus Micrococcus.

Double immunodiffusion tests were performed with crude extracts from various Micrococcus species and antisera against catalase of Micrococcus luteus CCM 169. Cell-free extracts of M. lylae ATCC 27566 exhibited good cross-reaction. Cell-free extracts or catalase enriched preparations of M. varians reacted very weakly and no reaction has been found with preparation of M. kristinae, M. nishinomiyaensis, M. roseus and M. sedentarius. The quantitative microcomplement fixation assay also revealed a closer relationship between M. luteus and M. lylae than between M. luteus and M. varians. Strains of other Micrococcus species reacted in the microcomplement assay with M. luteus antiserum just a weakly as non-related strains, e.g. Staphylococcus aureus or Cellulomonas cartalyticum.

Catalase↗
PubMed1973

Stimulation of lactic acid bacteria by a micrococcus isolate: evidence for multiple effects.

Growth of, and rate of acid production by, six cultures of lactic acid bacteria were increased in the presence of Micrococcus isolate F4 or a preparation of its capsular material. Concentrations of hydrogen peroxide found in pure cultures of the lactic acid bacteria were not detectable, or were greatly reduced, in mixed culture with Micrococcus isolate F4. The capsular material was not as effective as whole cells in preventing accumulation of H(2)O(2). Catalase stimulated growth of, and the rate of acid production by, the lactic acid bacteria, but not to the same extent as Micrococcus isolate F4 in some cultures. The existence of two mechanisms for micrococcal stimulation of the lactic acid bacteria is postulated. One mechanism involves removal of H(2)O(2); the other has not been characterized.

Animals↗
PubMed1986

Rapid lysostaphin test to differentiate Staphylococcus and Micrococcus species.

A rapid, simple lysostaphin lysis susceptibility test to differentiate the genera Staphylococcus and Micrococcus was evaluated. Of 181 strains from culture collections, 95 of 95 Staphylococcus strains were lysed, and 79 of 79 Micrococcus strains were not lysed. The seven Planococcus strains were resistant. Clinical isolates (890) were tested with lysostaphin and for the ability to produce acid from glycerol in the presence of erythromycin. Overall agreement between the methods was 99.2%. All clinical Micrococcus strains (43) were resistant to lysostaphin, and all clinical Staphylococcus strains (847) were susceptible. Seven of the Staphylococcus strains did not produce acid from glycerol in the presence of erythromycin. This lysostaphin test provides results in 2 h. It is easier to perform than previously described lysostaphin lysis methods. It is also more rapid and accurate than the glycerol-erythromycin test.

Bacteriological Techniques↗
PubMed1991

[Micrococcus luteus: a rare pathogen of valve prosthesis endocarditis].

A rare case of prosthetic valve endocarditis caused by Micrococcus luteus is described and compared with the few cases reported in the literature, as well as the clinical features, microbiological profile, therapy, and prognosis of common prosthetic valve endocarditis. Micrococcus luteus is a constituent of the normal human buccal bacterial flora which forms yellowish colonies and appears as a gram-positive coccus typically arranged in tetrades. Although of low virulence, the germ may become pathogenic in patients with impaired resistance, colonizing the surface of heart valves. In contrast to staphylococci (for which it may easily be mistaken) it is usually penicillin-sensitive. However, the most promising antibiotic regimen proposed for treatment of Micrococcus luteus seems to be a combination of vancomycin, amikacin, and rifampicin. If the infection leads to severe hemodynamic alterations, however, valve replacement may become necessary similar to the situation in prosthetic valve endocarditis caused by more aggressive and highly resistant bacteria.

Aged↗
PubMed1987

Accelerated tissue repair induced by micrococcus varians.

The present investigation was undertaken to study the effect of inoculated Micrococcus varians organisms on developing granulation tissue in rats. Subcutaneously implanted hollow cylindrical cellulose sponges were used as an inductive matrix for the growth of granulation tissue. The control implants were injected immediately after implantation with 1 milliliter of physiologic saline solution while the experimental implants were injected with a corresponding volume of saline solution containing live micrococci 10(7) microorganisms per milliliter. Cytologic and bacteriologic analyses of wound fluid aspirated from the central dead space of the implants were carried out three, seven and 14 days after implantation. Local blood flow and albumin extravasation were measured on day seven and granulation tissue grown into the implants was analyzed chemically on days seven and 14. No macroscopic infection with pus formation occurred, while Micrococcus varians was cultured from each inoculated implant. In the inoculated implants, the number of wound fluid neutrophils, granulation tissue blood flow and albumin extravasation increased significantly above the control level. Correspondingly, the amounts of granulation tissue deoxyribonucleic acid, nitrogen, collagen hydroxyproline, hexosamines and uronic acids in the inoculated implants exceeded significantly the control value on both days seven and 14. To conclude, inoculation of experimental wounds with nonpathogenic Micrococcus varians organisms enhanced local inflammatory reaction and blood flow, and promoted granulation tissue formation.

Animals↗
PubMed1981

Reduced transcription activity of rat liver chromatin after protein restriction and selective digestion of nuclei with micrococcus nuclease.

Restriction of protein intake in the diet has been shown to produce a change in transcription activity as determined in vitro. Conditions for a reduced transcription activity were investigated with selective digestion of nuclei with micrococcus nuclease (EC 3.1.4.7). Liver nuclei from young male rats fed a diet containing either 20 or 3% casein for 6 days were digested with 1.3 microgram of micrococcus nuclease protein/mg of nuclear DNA (specific enzyme activity 15,000 or 150 units/mg of protein). Part of the chromatin-bound RNA polymerase activity was transferred from the 2,000 x g to the 102,000 x g pellet. Independent of the type of endonuclease use, the specific activity of chromatin-bound and soluble RNA polymerase I plus III was similar in the two groups of rats. After protein restriction RNA polymerase II activity was significantly diminished in the 2,000 x g pellet, and was unchanged in the 102,000 x g pellet. Heparin-stimulated and soluble RNA polymerase II activities were significantly reduced. Number and length of RNA chains synthetized by chromatin-bound RNA polymerase I plus III remained unchanged by dietary treatment. After a low protein diet, RNA polymerase II in the absence and presence of heparin synthesized an unchanged number of RNA chains with reduced length. A selective digestion of chromatin with micrococcus nuclease is needed to show the reduction in RNA polymerase II activity after protein restriction.

Animals↗
PubMed1987

Pitted keratolysis. The role of Micrococcus sedentarius.

Though pitted keratolysis of the foot is generally viewed to be caused by bacteria, there is confusion regarding the identity of the causative organism. Species of Corynebacterium, Actinomyces, Dermatophilus, and Micrococcus have been proposed by various investigators. We have studied eight cases of pitted keratolysis and have cultured an organism identified as Micrococcus sedentarius on the basis of colonial morphology, micromorphology, biochemical reactions, and chemical analysis of whole-cell components. Furthermore, pitted keratolysis was produced experimentally in a human volunteer by applying M sedentarius under an occlusive dressing onto the surface of the heel.

Bacteriological Techniques↗