Eukaryotic Promoters Can Direct Protein Synthesis in Gram-Negative Bacteria

2003 ◽  
Vol 6 (3-4) ◽  
pp. 211-218 ◽  
Author(s):  
Sylvie Goussard ◽  
Catherine Grillot-Courvalin ◽  
Patrice Courvalin
Keyword(s):  
Protein Synthesis ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Eukaryotic Promoters

scholarly journals Evernimicin Binds Exclusively to the 50S Ribosomal Subunit and Inhibits Translation in Cell-Free Systems Derived from both Gram-Positive and Gram-Negative Bacteria

2000 ◽  
Vol 44 (5) ◽  
pp. 1121-1126 ◽  
Author(s):  
Paul M. McNicholas ◽  
David J. Najarian ◽  
Paul A. Mann ◽  
David Hesk ◽  
Roberta S. Hare ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Dissociation Constants ◽  
Wide Spectrum ◽  
Ribosomal Subunit ◽  
Gram Negative Bacteria ◽  
Metabolic Labeling ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Free Translation

ABSTRACT Evernimicin (SCH 27899) is a new antibiotic with activity against a wide spectrum of gram-positive bacteria and activity against some gram-negative bacteria. Previous metabolic labeling studies indicated that evernimicin specifically inhibited protein synthesis inStaphylococcus aureus. Using a susceptibleEscherichia coli strain, we demonstrated that evernimicin also inhibited protein synthesis in E. coli. In cell-free translation assays with extracts from either E. coli orS. aureus, evernimicin had a 50% inhibitory concentration of approximately 125 nM. In contrast, cell-free systems derived from wheat germ and rabbit reticulocytes were inhibited only by very high levels of evernimicin. Evernimicin did not promote transcript misreading. [14C]evernimicin specifically bound to the 50S subunit from E. coli. Nonlinear regression analysis of binding data generated with 70S ribosomes from E. coli andS. aureus and 50S subunits from E. colireturned dissociation constants of 84, 86, and 160 nM, respectively. In binding experiments, performed in the presence of excess quantities of a selection of antibiotics known to bind to the 50S subunit, only the structurally similar drug avilamycin blocked binding of [14C]evernimicin to ribosomes.

scholarly journals Bacterial longevity requires protein synthesis and a stringent response

2019 ◽  
Author(s):  
Liang Yin ◽  
Hongyu Ma ◽  
Ernesto S. Nakayasu ◽  
Samuel H. Payne ◽  
David R. Morris ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Bacterial Species ◽  
Rhodopseudomonas Palustris ◽  
Growth Arrest ◽  
Model Organism ◽  
Stringent Response ◽  
Gram Negative Bacteria ◽  
Homogeneous Population ◽  
Gram Negative ◽  
Specific Proteins

ABSTRACTGram-negative bacteria in infections, biofilms and industrial settings often stop growing due to nutrient depletion, immune responses or environmental stresses. Bacteria in this state tend to be tolerant to antibiotics and are often referred to as dormant.Rhodopseudomonas palustris, a phototrophic α-proteobacterium, can remain fully viable for more than four months when growth is arrested. Here, we show that protein synthesis, specific proteins involved in translation and a stringent response are required for this remarkable longevity. Because it can generate ATP from light during growth arrest,R. palustrisis an extreme example of a bacterial species that will stay alive for long periods of time as a relatively homogeneous population of cells and it is thus an excellent model organism for studies of bacterial longevity. There is evidence that other Gram-negative species also continue to synthesize proteins during growth arrest and that a stringent response is required for their longevity as well. Our observations challenge the notion that growth-arrested cells are necessarily dormant and metabolically inactive, and suggest that such bacteria may have a level of metabolic activity that is higher than many would have assumed. Our results also expand our mechanistic understanding of a crucial but understudied phase of the bacterial life cycle.IMPORTANCEWe are surrounded by bacteria; but they do not completely dominate our planet despite the ability of many to grow extremely rapidly in the laboratory. This has been interpreted to mean that bacteria in nature are often in a dormant state. We investigated life in growth arrest ofRhodopseudomonas palustris, a proteobacterium that stays alive for months when it is not growing. We found that cells were metabolically active; they continued to synthesize proteins and mounted a stringent response, both of which were required for their longevity. Our results suggest that long-lived bacteria are not necessarily inactive but have an active metabolism that is well adjusted to life without growth.

Infectious disease

2019 ◽  
Author(s):  
Stevan R. Emmett ◽  
Nicola Hill ◽  
Federico Dajas-Bailador
Keyword(s):  
Cell Wall ◽  
Protein Synthesis ◽  
Nucleic Acid ◽  
Outer Membrane ◽  
Bacterial Cell ◽  
Bacterial Cell Wall ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Antibiotics include an extensive range of agents able to kill or prevent reproduction of bacteria in the body, without being overly toxic to the patient. Traditionally derived from living organisms, most are now chemically synthesized and act to disrupt the integrity of the bacterial cell wall, or penetrate the cell and disrupt protein synthesis or nucleic acid replication. Typically, bacteria are identified according to their ap­pearance under the microscope depending on shape and response to the Gram stain test. Further identification is obtained by growth characteristics on various types of culture media, based on broth or agar, biochemical and immunological profiles. Further testing on broth or agar determines antibiotic sensitivity to guide on anti­biotic therapy in individual patients. This process can take 24– 48 hours to culture and a further 24– 48 hours to measure sensitivities. Increasingly, new technology, e.g. Matrix Assisted Laser Desorption Ionization— Time of Flight (MALDI- TOF) and nucleic acid amplification as­says, are being used to provide more rapid identification. The Gram classification, however, is still widely referred to as it differentiates bacteria by the presence or absence of the outer lipid membrane (see Figure 11.1), a fundamental characteristic that influences antibiotic management. Antimicrobial agents rely on selective action exploiting genetic differences between bacterial and eukaryotic cells. They target bacterial cell wall synthesis, bacterial protein synthesis, microbial DNA or RNA synthesis, by acting on bacterial cell metabolic pathways or by inhibiting the ac­tion of a bacterial toxin (see Table 11.1). Both Gram- positive and Gram- negative bacteria possess a rigid cell wall able to protect the bacteria from varying osmotic pressures (Figure 11.1). Peptidoglycan gives the cell wall its rigidity and is composed of a glycan chain of complex alternating carbohydrates, N- acetylglucosamide (N- ATG), and N- acetylmurcarinic acid (N- ATM), that are cross- linked by peptide (or glycine) chains. In Gram-positive bacteria, the cell wall contains multiple peptido­glycan layers, interspersed with teichoic acids, whereas Gram- negative bacteria contain only one or two peptido­glycan layers that are surrounded by an outer membrane attached by lipoproteins. The outer membrane contains porins (which regulate transport of substances into and out of the cell), lipopolysaccharides, and outer proteins in a phospholipid bilayer. For both Gram- negative and Gram-positive bacteria, peptidoglycan synthesis involves about 30 bacterial enzymes acting over three stages. Since the cell wall is unique to bacteria, it makes a suitable target for antibiotic therapy.

scholarly journals Virulence of Entamoeba histolytica trophozoites. Effects of bacteria, microaerobic conditions, and metronidazole.

1984 ◽  
Vol 160 (2) ◽  
pp. 353-368 ◽  
Author(s):  
R Bracha ◽  
D Mirelman
Keyword(s):  
Hydrogen Peroxide ◽  
Protein Synthesis ◽  
Entamoeba Histolytica ◽  
Cultured Cells ◽  
Reducing Power ◽  
Considerable Extent ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Enzymatic Systems ◽  
Microaerobic Conditions

The association of axenically grown trophozoites of Entamoeba histolytica strains HK-9 or HM-1:IMSS with various types of gram-negative bacteria for relatively short periods markedly increased their virulence, as evidenced by their ability to destroy monolayers of tissue-cultured cells. Interaction of trophozoites with bacteria that were heat inactivated, glutaraldehyde fixed, or disrupted by sonication, or bacteria treated with inhibitors of protein synthesis, did not augment amebic virulence. Lethally irradiated bacteria, however, retained their stimulative properties and trophozoites that ingested bacteria were protected from the toxic effects of added hydrogen peroxide. An increase in virulent properties of amebae was also found in experiments carried out under microaerobic conditions (5% O2, 10% CO2). The augmentation of amebic virulence due to association with bacteria was specifically blocked by metronidazole, but not by tetracycline or aminoglycosides, and the rate of metronidazole uptake in stimulated trophozoites was two to three times higher. The results obtained suggest that virulence of axenically grown E. histolytica trophozoites may depend to a considerable extent on the cell's reducing power. Both microaerobic conditions and the association with bacteria apparently stimulate the electron transport system of the ameba. Bacteria may function as broad range scavengers for oxidized molecules and metabolites through the contribution of enzymatic systems, components, or products.

scholarly journals Activity of RX-04 Pyrrolocytosine Protein Synthesis Inhibitors against Multidrug-Resistant Gram-Negative Bacteria

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Anna Vickers ◽  
Shazad Mushtaq ◽  
Neil Woodford ◽  
Michel Doumith ◽  
David M. Livermore
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Protein Synthesis ◽  
Acinetobacter Baumannii ◽  
Ribosomal Subunit ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Protein Synthesis Inhibitors ◽  
Gram Negative ◽  
Content Type ◽  
Active Analog

ABSTRACT Pyrrolocytosines RX-04A to -D are designed to bind to the bacterial 50S ribosomal subunit differently from currently used antibiotics. The four analogs had broad anti-Gram-negative activity: RX-04A—the most active analog—inhibited 94.7% of clinical Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa at 0.5 to 4 μg/ml, with no MICs of >8 μg/ml. MICs for multidrug-resistant (MDR) carbapenemase producers were up to 2-fold higher than those for control strains; values were highest for one Serratia isolate with porin and efflux lesions. mcr-1 did not affect MICs.

Developmentally regulated protein synthesis during intraperiplasmic growth of Bdellovibrio bacteriovorus 109J

1998 ◽  
Vol 44 (1) ◽  
pp. 50-55 ◽  
Author(s):  
M P McCann ◽  
H T Solimeo ◽  
F Cusick, Jr. ◽  
B Panunti ◽  
C McCullen
Keyword(s):  
Complex System ◽  
Protein Synthesis ◽  
Gram Negative Bacteria ◽  
Two Dimensional ◽  
Developmental Sequence ◽  
Developmentally Regulated ◽  
Prey Cell ◽  
Bdellovibrio Bacteriovorus ◽  
Gram Negative ◽  
Attack Phase

Bdellovibrio bacteriovorus 109J is an obligate intraperiplasmic predator of other Gram-negative bacteria. Collision with a suitable prey cell initiates a developmental sequence ultimately resulting in the destruction of the prey cell and the production of progeny bdellovibrios. Two-dimensional gel analysis of patterns of protein synthesis at various times in a synchronously growing culture of Bdellovibrio bacteriovorus 109J revealed over 30 polypeptides whose syntheses are developmentally regulated. The majority of these polypeptides fall into nine categories: attack phase specific or one of eight different kinetic groups expressed during the intraperiplasmic growth phase. The results indicate that Bdellovibrio bacteriovorus 109J has a complex system for regulating gene expression during its developmental cycle.Key words: gene regulation, development, two-dimensional gels, Bdellovibrio bacteriovorus.

Bacterial-Mucosal Cell Junctional Complexes

1974 ◽  
Vol 32 ◽  
pp. 144-145
Author(s):  
Roger C. Wagner
Keyword(s):  
Intestinal Wall ◽  
Rat Colon ◽  
Mucosal Cell ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mucosal Cells ◽  
Mucosal Lining ◽  
Degenerative Alterations ◽  
Junctional Complexes ◽  
Intestinal Mucosal Cells

Bacteria exhibit the ability to adhere to the apical surfaces of intestinal mucosal cells. These attachments either precede invasion of the intestinal wall by the bacteria with accompanying inflammation and degeneration of the mucosa or represent permanent anchoring sites where the bacteria never totally penetrate the mucosal cells.Endemic gram negative bacteria were found attached to the surface of mucosal cells lining the walls of crypts in the rat colon. The bacteria did not intrude deeper than 0.5 urn into the mucosal cells and no degenerative alterations were detectable in the mucosal lining.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

Ultrastructure of periplasmic bodies in gram-negative bacteria

1990 ◽  
Vol 48 (3) ◽  
pp. 640-641
Author(s):  
Xie Nianming ◽  
Ding Shaoqing ◽  
Wang Luping ◽  
Yuan Zenglin ◽  
Zhan Guolai ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Campylobacter Jejuni ◽  
Proteus Mirabilis ◽  
Shigella Flexneri ◽  
Morphological Description ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Clostridium Tetani ◽  
Gram Negative ◽  
Brucella Canis

Perhaps the data about periplasmic enzymes are obtained through biochemical methods but lack of morphological description. We have proved the existence of periplasmic bodies by electron microscope and described their ultrastructures. We hope this report may draw the attention of biochemists and mrophologists to collaborate on researches in periplasmic enzymes or periplasmic bodies with each other.One or more independent bodies may be seen in the periplasmic space between outer and inner membranes of Gram-negative bacteria, which we called periplasmic bodies. The periplasmic bodies have been found in seven species of bacteria at least, including the Pseudomonas aeroginosa. Shigella flexneri, Echerichia coli. Yersinia pestis, Campylobacter jejuni, Proteus mirabilis, Clostridium tetani. Vibrio cholerae and Brucella canis.

Dual stain kit for the microscopic gram classification of ocular infection bacteria

1993 ◽  
Vol 51 ◽  
pp. 248-249
Author(s):  
Jacob S. Hanker ◽  
Dale N. Holdren ◽  
Kenneth L. Cohen ◽  
Beverly L. Giammara
Keyword(s):  
Contact Lenses ◽  
Ocular Infection ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Gram Staining ◽  
Ocular Infections ◽  
Different Types ◽  
Culture Positive ◽  
Increased Susceptibility

Keratitis and conjunctivitis (infections of the cornea or conjunctiva) are ocular infections caused by various bacteria, fungi, viruses or parasites; bacteria, however, are usually prominent. Systemic conditions such as alcoholism, diabetes, debilitating disease, AIDS and immunosuppressive therapy can lead to increased susceptibility but trauma and contact lens use are very important factors. Gram-negative bacteria are most frequently cultured in these situations and Pseudomonas aeruginosa is most usually isolated from culture-positive ulcers of patients using contact lenses. Smears for staining can be obtained with a special swab or spatula and Gram staining frequently guides choice of a therapeutic rinse prior to the report of the culture results upon which specific antibiotic therapy is based. In some cases staining of the direct smear may be diagnostic in situations where the culture will not grow. In these cases different types of stains occasionally assist in guiding therapy.

Sign in / Sign up

Export Citation Format

Share Document