Alkaline phosphatase-conjugated oligonucleotide probes were developed to detect the gene coding for Vero toxin 1 (VT1) and Vero toxin 2 (VT2). Using these probes, 3 hr was enough to detect VT genes when suspicious colonies of enterohaemorrhagic Escherichia coli (EHEC) were obtained on an agar plate. The results of a hybridization test with 144 isolates of EHEC O157 and one isolate of Shigella dysenteriae Type 1 agreed exactly with the immunological detection, reversed passive latex agglutination (RPLA) test, of VTs in their culture supernatants. The sensitivity levels of these probes for the detection of VT genes were 100%. The specificity of these probes were also tested with a total of 1,002 strains of Escherichia coli other than EHEC and 8 strains of Shigella sp. other than Shigella dysenteriae Type 1; the results showed 100% specificity.
Eighteen isolates of anaerobic coryneforms from human bone marrow and skin and four type strains of Propionibacterium were studied chemically, biochemically and antigenically. All of the isolates were identified as Propionibacterium acnes; of the 18 isolates, 16 belonged to serotype I and two to serotype II. By means of gas liquid chromatography and mass spectral analysis, a large amount of iso-type fatty acids, such as iso-pentadecanoic and iso-heptadecanoic acids were detected in whole cells of isolates and type strains. Antitumor and adjuvant effects of the isolates and type strains were found to differ considerably among the strains. One of the isolates, P. acnes C-7, which showed potent biological activities was fractionated by hot phenol-water extraction.The resulting insoluble middle layer was found the most effective in tumor protection, adjuvant action in immune response and phagocytic activity in mice.
Lividomycin specifically inhibited bacterial protein synthesis and had codon misreading activity. Lividomycin, moreover, stimulated the binding of aminoacyl-transfer ribonucleic acid to ribosomes, but did not show any significant effects on the formation of aminoacyl-transfer ribonucleic acid and the puromycin reaction.Lividomycin (LV), a new pentasaccharide antibiotic containing 3-deoxy-D-glucosamine, deoxystreptamine, D-ribose, neosamine B and D-mannose (9) showed antibacterial activity toward several species of gram-positive and -negative bacteria (4) and misreading activity in vitro (6). This paper deals with the activities of LV on several steps in bacterial protein synthesis and with the mode of codon misreading in an Escherichia coli cell-free system directed by polynucleotides.E. coli ML1410 was used throughout the experiments. The preparation of ribosomes and supernatant fluid from E. coli and the reaction mixture for polypeptide synthesis were those described by Nirenberg and Matthaei (8). The
Enzymatic inactivation of lividomycin (LV) was attempted with nine clinical isolates of staphylococci including LV-susceptible and -resistant strains. LV inactivation and the incorporation into LV of 32P from y-32P-adenosine triphosphate were demonstrated in the presence of cell-free extracts from LV-resistant strains but not from LV-susceptible ones. The enzyme was purified approximately 82-fold from a resistant Staphylococcus aureus strain by means of ammonium sulfate fractionation and column chromatography. Some properties of the partially purified LV-phosphorylating enzyme were quite similar to those of an enzyme from Escherichia coli carrying an R factor conferring LV resistance, and the phosphorylated product of the drug was also found to be identical with that produced by E. coli carrying an R factor, i.e., 5"-phosphoryl-LV.Many enzymes which inactivate aminoglycosidic antibiotics have been reported in drugresistant strains of bacteria of several species (1, 12). We reported that the lividomycin (LV)-inactivating enzyme capable of phosphorylating the drug was demonstrated in resistant strains of Pseudomonas aeruginosa (9) and of Escherichia coli carrying an R factor (19). Further studies indicated that the inactivated LV was a monophosphorylated product, in which the Dribose moiety of LV was phosphorylated (10,20).In a survey of Staphylococcus aureus, LVresistant strains whose growth was not inhibited by 50 qig of LV/ml were isolated at a frequency of 23.4% (6). This paper deals with some properties of the LV-inactivating enzyme and the relation between LV resistance and the enzyme activity.MATERIALS AND METHODS Bacterial strains. The nine clinical isolates used included three LV-resistant and three LV-susceptible strains of S. aureus and three LV-resistant strains of S. epidermidis. These strains were selected at random from our stocks.Preparation of the S-105 fraction. Glucose-peptone broth (pH 7.2) consisted of 10 g of peptone, 5 g of NaCl, 3 g of glucose, 4 g of yeast extract, and 1,000 ml of water. Each strain was cultured in 2 liters of glucose-peptone broth at 35 C for 5 h with shaking, after 18 h of precultivation in the same broth at 37 C without shaking.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.