A new coagulase-negative subspecies, Staphylucuccus supruphyticus subsp. bovis, is described on the basis of a study of five strains isolated from the anterior nares of cows. This subspecies is differentiated from the other novobiocin-resistant staphylococci by its phenotypic properties, cell wall composition, and levels of genetic relatedness. The type strain of the new subspecies is Kv 12 (=CCM 4410).A total of 28 species and 8 subspecies are already recognized in the genus Staphylococcus, as listed in the 9th ed. of Bergey's Manual of Determinative Bacteriology (19). In addition, five new staphylococcal species have been validly published since 1992 (S. muscae, S. pasteuri, S. piscifeimentans, S. pulvereri, and S. vitulus) (8, 17,(34)(35)(36).Within the cluster of coagulase-negative staphylococci, 11 novobiocin-resistant species (S. arlettae, S. cohnii, S. equorum, S. gallinarum, S. kloosii, S. lentus, S. pulvereri, S. saprophyticus, S. sciuri, S. vitulus, and S. xylosus) (10,23,27,29,30,35,36) and two subspecies (S. cohnii subsp. cohnii and S. cohnii subsp. urealyticus) (24) have been established so far. In this paper, a new taxonomic group of novobiocin-resistant staphylococci closely related to S. saprophyticus is described. These bacteria were isolated in about 7% of the nostrils of healthy cows. They were allocated on the basis of their physiological and biochemical properties, cell wall composition, and genetic relatedness to a separate subspecies, S. saprophyticus subsp. bovis. MATERIALS AND METHODSBacterial strains. Five strains (KV 12T = CCM 4410, KV 19, KV 20, KV 30, and KV 56 =CCM 4411) were isolated from the anterior nares of healthy cows brought to the Olomouc slaughterhouse from North Moravia. The isolation medium was nutrient broth (Oxoid) supplemented with 7% NaCl and blood agar base no. 2 (Oxoid) mixed with 5% defibrinated ovine blood. The latter was also used for the propagation of all of the isolates.The 20 type strains of the genus Staphylococcus (see Table 6) for the DNA-DNA hybridization test were obtained from the American Type Culture Collection, Rockville, Md.; the Czech Collection of Microorganisms, Masaryk University, Brno, Czech Republic; and the Deutsche Sammlung von Mikroorganismen, Braunschweig, Germany.All of the strains were maintained as frozen suspensions in glycerol broth at -25°C (20) and were also maintained in a freeze-dried state.Phenotypic characteristics. The following properties were determined by methods previously described in detail (11, 15, 17): cell and colony morphology; pigmentation; motility; anaerobic growth in thioglycolate medium; production of catalase, oxidase, and coagulase in rabbit and bovine plasma; production of clumping factor, fibrinolysin, acetylmethylcarbinol, urease, arginine-dihydrolase, alkaline and acid phosphatases, cascinase, gelatinase, hyaluronidase, heat-labile and heat-stable nucleases, lysozyme, lecithinase, a-and P-hemolysins, p-galactosidase, indole, hydrogen sulfide, phenylalanine deaminase, ornithine and lysine decarboxylases...
In vitro subcellular and cellular systems have important and irreplaceable roles in the metabolic investigations that precede the development of new potential drugs. Of these model systems, tissue slices are probably the nearest to in vivo conditions. From the experimental and complexity points of view, perfused organs lie midway between tissue slices and whole organism. Preparation and working with liver slices is quick and easy, and, excess material can be cryopreserved and stored untill the next experiment. Slices can be prepared from a wide variety of organs and it is possible to co-incubate them. Another important feature is the possibility of interspecies comparison of slices. Different experiments can be run both in the short-term as well as long-term incubations. Each in vitro system has an important place for example, in the development of new medicaments. It is therefore important to compare and supplement experimental results from different in vitro systems when extrapolating to in vivo situations is done.
1. Biotransformation pathways of the cyclin-dependent kinase inhibitor 6-benzylamino-2-(3-hydroxypropylamino)-9-isopropylpurine (bohemine) by mouse liver microsomes in vitro were investigated. 2. Metabolite profiles of [8-(3)H]-labelled bohemine were established by TLC/(3)H-autoradiography and enzymatic and MS analyses were used to elucidate the chemical structures of the metabolites. The structures of the main primary metabolites were confirmed by synthesis of authentic compounds. 3. A schema of the primary NADPH-dependent pathways has been proposed involving N(2)- and N9-dealkylation, N(6)-debenzylation, aromatic hydroxylation, and C2 side chain oxidation of bohemine. Three of the primary metabolites detected, 6-(benzylamino)-2-(3-hydroxypropylamino)purine (M4), 6-amino-2-(3-hydroxypropylamino)-9-isopropylpurine (M5) and 6-(4-hydroxybenzylamino)-2-(3-hydroxypropylamino)-9-isopropylpurine (M6), all retaining their parent primary hydroxyl group, were subsequently shown to be converted, by a liver cytosolic NAD(+)-dependent system, into their corresponding carboxylic acids. M6 was subject to microsomal glycosidations requiring UDP-sugar donors. NADPH-dependent conversion of M6 into M5 by microsomes was also demonstrated. 4. Cytochrome P450 (CYP) enzymes-selective inhibitors were used to identify CYPs involved in bohemine biotransformation. The findings suggested that CYP2a and CYP3a substantially contributed to the NADPH-dependent bohemine transformation in vitro. 5. The findings will facilitate experiments designed to dissect enzymatic systems catalysing clearance of C2,C6,N9-trisubstituted purine compounds from mammalian tissues.
Isolates of Stenotrophomonas maltophilia species display the feature "temperature-dependent susceptibility" (TDS) to antibiotics. Both 30TDS strains (at least 4 times lower value of minimum inhibitory concentration (MIC) of an antibiotic at 30 than at 37 degrees C) and 37TDS strains (at least 4 times lower value of MIC at 37 than at 30 degrees C) were described. Changes in the distribution of saturated and unsaturated fatty acids (FA) at 30 and 37 degrees C were considered as one of possible causes of the TDS phenomenon. Gas chromatography was used to determine the distribution of individual FA in five 37TDS strains of S. maltophilia (Group I); in five strains with MIC values unaffected by the cultivation temperature (Group II) and in six 30TDS (four strains) or 30/37TDS (two strains) isolates (Group III). At identical temperatures, no statistically significant differences in the distribution of major FA (iso-15:0, anteiso-15:0, 16:0 and 16:1) were registered between individual groups. Statistically significant (p < 0.05) differences between groups were found in minor FA only (iso-16:0, iso-17:0 and iso-17:1). Distribution changes of cellular FA at 30 and 37 degrees C can be considered to play only a minor role in the formation of the TDS phenomenon.
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