novobiocin and Hemolysis

Topics: Adult; Altitude; Bilirubin; Biological Transport; Erythrocyte Aging; Female; Hemolysis; Hepatitis B; Hexosyltransferases; Humans; Hyperbilirubinemia; Hyperbilirubinemia, Hereditary; Infant, Newborn; Jaundice; Liver; Novobiocin; Portacaval Shunt, Surgical; Pregnancy; Vitamin K

Chromosomally encoded low membrane permeability and highly efficient efflux systems are major mechanisms by which Pseudomonas aeruginosa evades antibiotic actions. Our previous reports have shown that amphiphilic tobramycin-fluoroquinolone hybrids can enhance efficacy of fluoroquinolone antibiotics against multidrug-resistant (MDR) P. aeruginosa isolates. Herein, we report on a novel class of tobramycin-lysine conjugates containing an optimized amphiphilic tobramycin-C12 tether that sensitize Gram-negative bacteria to legacy antibiotics. Combination studies indicate the ability of these conjugates to synergize rifampicin and minocycline against MDR and extensively drug resistant (XDR) P. aeruginosa isolates and enhance efficacy of both antibiotics in the Galleria mellonella larvae in vivo infection model. Mode of action studies indicate that the amphiphilic tobramycin-lysine adjuvants enhance outer membrane cell penetration and affect the proton motive force, which energizes efflux pumps. Overall, this study provides a strategy for generating effective antibiotic adjuvants that overcome resistance of rifampicin and minocycline in MDR and XDR Gram-negative bacteria including P. aeruginosa.

Topics: Anti-Bacterial Agents; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Gram-Positive Bacteria; Hemolysis; Lysine; Microbial Sensitivity Tests; Minocycline; Models, Biological; Rifampin; Tobramycin

The 90 kDa heat shock protein, Hsp90, is an abundant molecular chaperone participating in the cytoprotection of eukaryotic cells. Here we analyzed the involvement of Hsp90 in the maintenance of cellular integrity using partial cell lysis as a measure. Inhibition of Hsp90 by geldanamycin, radicicol, cisplatin, and novobiocin induced a significant acceleration of detergent- and hypotonic shock-induced cell lysis. The concentration and time dependence of cell lysis acceleration was in agreement with the Hsp90 inhibition characteristics of the N-terminal inhibitors, geldanamycin and radicicol. Glutathione and other reducing agents partially blocked geldanamycin-induced acceleration of cell lysis but were largely ineffective with other inhibitors. Indeed, geldanamycin treatment led to superoxide production and a change in membrane fluidity. When Hsp90 content was diminished using anti-Hsp90 hammerhead ribozymes, an accelerated cell lysis was also observed. Hsp90 inhibition-induced cell lysis was more pronounced in eukaryotic (yeast, mouse red blood, and human T-lymphoma) cells than in bacteria. Our results indicate that besides the geldanamycin-induced superoxide production, and a consequent increase in cell lysis, inhibition or lack of Hsp90 alone can also compromise cellular integrity. Moreover, cell lysis after hypoxia and complement attack was also enhanced by any type of Hsp90 inhibition used, which shows that the maintenance of cellular integrity by Hsp90 is important in physiologically relevant lytic conditions of tumor cells.

Topics: Animals; Base Sequence; Benzoquinones; Catalytic Domain; Cell Hypoxia; Cell Survival; Cisplatin; Consensus Sequence; Hemolysis; HSP90 Heat-Shock Proteins; Humans; Jurkat Cells; Kinetics; Lactams, Macrocyclic; Lactones; Macrolides; Membrane Fluidity; Mice; Molecular Sequence Data; Novobiocin; Nucleic Acid Conformation; Quinones; Rats; Superoxides; Tumor Cells, Cultured

One hundred reference strains and 1,240 clinical isolates representing 26 species of the family Micrococcaceae were used to evaluate the potential of tests for synergistic hemolysis, adherence to glass, pyroglutamyl-beta-naphthylamide hydrolysis, and susceptibility to a set of five antimicrobial agents for differentiating these species and strains within the species. Sixty-eight percent of the clinical isolates exhibited synergistic hemolysis; 69% of the clinical staphylococci but none of the micrococci or stomatococci were adherence positive, and 92% of the strong positive adherence reactions were produced by strains of Staphylococcus epidermidis. Strains from 15 of the species were pyroglutamyl-beta-naphthylamide positive, but this test separated Staphylococcus xylosus from other novobiocin-resistant staphylococci and Staphylococcus intermedius from other coagulase-positive species. A polymyxin B disk helped differentiate S. epidermidis from most other coagulase-negative staphylococci, and a bacitracin disk (10 U) helped differentiate Staphylococcus haemolyticus from most other novobiocin-susceptible staphylococci. All strains that were susceptible to furazolidone and resistant to Taxo A disks (bacitracin, 0.04 U; BBL Microbiology Systems, Cockeysville, Md.) were staphylococci. We observed a 91% correlation between species identification obtained with the Staph-Ident system (Analytab Products, Plainview, N.Y.) and conventional methods; but the micrococci and stomatococci were incorrectly identified as staphylococci with Staph-Ident, and several isolates of S. epidermidis were misidentified as Staphylococcus hominis because they were alkaline phosphatase negative. Both these problems can be prevented by adding the simple tests we describe to those already recommended when the Staph-Ident system is used to identify isolates of gram-positive, catalase-positive cocci.

Topics: Bacitracin; Bacterial Adhesion; Coagulase; Culture Media; Furazolidone; Hemolysis; Humans; Microbial Sensitivity Tests; Micrococcaceae; Novobiocin; Polymyxins; Pyrrolidinones; Staphylococcus

Seven beta-hemolytic Streptococcus salivarius isolates produced bacteriocin-like inhibitory activity in deferred antagonism tests using a set of nine indicator bacteria (I1-I9). Five of these S. salivarius strains (KWF, TOVE-R, K17, K21, and K26) were inhibitory to indicators I2, I5, I6, and I7. Mutated non-hemolytic derivatives showed concomitant loss of inhibitory activity against I2, I5, and I6, but retained activity against I7. Inhibitory activity against I2, I5, and I6 was restored in beta-hemolytic revertants of such mutants. Strain 3638 was inhibitory to all of the indicator organisms except I3, and this pattern of inhibitory activity was retained by non-hemolytic derivatives. It appeared that strain 3638 produced an additional broadly-active inhibitory agent, since a mutant (strain 3638A), which was apparently defective in the production of this inhibitor, retained both the beta-hemolytic and I2-, I5-, I6-, and I7-inhibitory activities. Non-hemolytic derivatives of strain 3638A were inhibitory only to I7. Strain 3638, therefore, appeared to produce at least three inhibitory agents: one active only on I7; another acting on I2, I5, and I6 (and associated with beta-hemolytic activity); and a third apparently active on all of the indicators other than I3. S. salivarius strain JH inhibited all nine indicator strains and possessed a beta-hemolytic character which differed from that of the other strains in being readily eliminated on treatment with the plasmid-curing agent novobiocin. Non-hemolytic derivatives of JH retained inhibitory activity against the complete set of indicators.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Bacteriocins; Culture Media; Dialysis; Hemolysis; Methylnitronitrosoguanidine; Novobiocin; Streptococcus

Reduction in caloric intake was associated with a greater absolute rise in the serum bilirubin concentration in patients with Gilbert's syndrome and partial hepatic bilirubin uridine diphosphate glucuronyltransferase (UDPG-T) dysfunction compared to patients with hemolytic unconjugated hyperbilirubinemia and normal subjects. Two patients with overt hemolysis but an exaggerated response to caloric deprivation had reduced UDPG-T activities comparable to Gilbert's syndrome. The UDPG-T activities in the other patients with hemolytic jaundice were normal. The combination of fasting and novobiocin in 2 normal subjects produced a greater increase in bilirubin level than either fasting or novobiocin alone. These data suggest that theunderlying UDPG-T dysfunction, rather than the prefasting level of unconjugated hyperbilirubinemia, is responsible for the diet-induced hyperbilirubinemia in Gilbert's syndrome. The diet test appears to differentiate Gilbert's syndrome from hemolytic jaundice as well as from normal subjects, irrespective of the initial serum bilirubin concentration.

Topics: Anemia, Hemolytic; Diet; Fasting; Gilbert Disease; Glucuronosyltransferase; Hemolysis; Humans; Hyperbilirubinemia; Hyperbilirubinemia, Hereditary; Liver; Novobiocin

An evaluation of criteria used in the identification of Vibrio parahaemolyticus showed that cultural responses varied with respect to growth in broth with 10% NaCl, type of hemolysis, reactions in triple sugar-iron-agar, and serological reactions. With few or no exceptions, cultures were positive for cytochrome oxidase, utilized glucose fermentatively, were sensitive to pteridine (0/129) and novobiocin, and failed to grow in Trypticase soy broth (TSB) without NaCl. A procedure employing a direct plating technique, with or without prior enrichment, was designed for the isolation and enumeration of V. parahaemolyticus. The plating medium consisted of 2.0% peptone, 0.2% yeast extract, 1.0% corn starch, 7% NaCl, and 1.5% agar, with the pH adjusted to 8.0. The enrichment broth was TSB with 7% NaCl. Dilutions of food homogenates were either spread directly on the plates or inoculated into enrichment broth. TSB enrichments were incubated at 42 C for 18 hr. A loopful of the TSB tubes then was streaked onto the direct plating medium. Incubation of plates was at 42 C for 24 to 48 hr. Smooth, white to creamy, circular, amylase-positive colonies were then picked as suspect V. parahaemolyticus. Confirmation of gram-negative, fermentative, oxidase-positive, pleomorphic rods sensitive to pteridine 0/129 was made by a fluorescent-antibody technique. With this procedure, a satisfactory quantitative recovery of known V. parahaemolyticus from inoculated seafoods was made possible. V. parahaemolyticus was nto isolated from other salted foods.

Topics: Amylases; Animals; Antigens, Bacterial; Bacteriological Techniques; Culture Media; Drug Resistance, Microbial; Electron Transport Complex IV; Erythrocytes; Fermentation; Fish Products; Fluorescent Antibody Technique; Food Microbiology; Glucose; Hemolysis; Humans; Immune Sera; Novobiocin; Pteridines; Rabbits; Sheep; Vibrio

Mycoplasma strains (B1, B2, CS, and S1A) were isolated from the saliva of normal cats. These were compared with a strain (CO) isolated from the eye of a cat with severe conjunctivitis. On the basis of morphology, biochemical reactions, and antigenic composition, two distinct species were recognizable. Strains CO, B1, and B2 were antigenically unrelated to the other species tested; strains CS and S1A possessed antigenic components in common with Mycoplasma arthritidis, M. salivarium, M. hominis, type 1, and M. orale, types 1 and 2. It was tentatively suggested that the two cat species be called M. felis and M. gateae, respectively.

Topics: Animals; Antigens; Cats; Chloramphenicol; Complement Fixation Tests; Conjunctivitis; Dihydrostreptomycin Sulfate; Erythromycin; Hemolysis; Immune Sera; Immunodiffusion; Lincomycin; Mycoplasma; Neomycin; Novobiocin; Rats; Saliva; Tetracycline

Topics: Anemia; Anemia, Hemolytic; Child; Hemolysis; Novobiocin; Toxicology

Topics: Anti-Bacterial Agents; Coumarins; Hemolysin Proteins; Hemolysis; Novobiocin; Staphylococcus