Use of Glycol Ethers for Selective Release of Periplasmic Proteins from Gram-Negative Bacteria

2007 ◽  
Vol 0 (0) ◽  
pp. 0-0 ◽  
Author(s):  
J.R. Allen ◽  
A.Y. Patkar ◽  
T.C. Frank ◽  
F.A. Donate ◽  
Y. ChunChiu ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Glycol Ethers ◽  
Gram Negative ◽  
Periplasmic Proteins

scholarly journals Secretin channel-interactors prevent antibiotic influx during type IV pili assembly in P. aeruginosa

2021 ◽  
Author(s):  
Hongbaek Cho ◽  
Oh Hyun Kwon ◽  
Joel W Sher ◽  
Bi-o Kim ◽  
You-Hee Cho
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Bacterial Pathogenesis ◽  
Type Iv Pili ◽  
Permeability Barrier ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Type Iv ◽  
Periplasmic Proteins ◽  
And Function

Type IV pili (T4P) are important virulence factors involved in host attachment and other aspects of bacterial pathogenesis. In Gram-negative bacteria, the T4P filament is polymerized from pilin subunits at the platform complex in the inner membrane (IM) and exits the outer membrane (OM) through the OM secretin channel. Although it is essential for T4P assembly and function, the OM secretin complexes can potentially impair the permeability barrier function of the OM and allow the entry of antibiotics and other toxic molecules. The mechanism by which Gram-negative bacteria prevent secretin-mediated OM leakage is currently not well understood. Here, we report a discovery of SlkA and SlkB (PA5122 and PA5123) that prevent permeation of several classes of antibiotics through the secretin channel of Pseudomonas aeruginosa type IV pili. We found these periplasmic proteins interact with the OM secretin complex and prevent toxic molecules from entering through the channel when there is a problem in the assembly of the T4P IM subcomplexes or when docking between the OM and IM complexes is defective.

Foreign signal peptides can constitute a barrier to functional expression of periplasmic proteins in Haemophilus influenzae

Microbiology ◽  
2003 ◽  
Vol 149 (11) ◽  
pp. 3155-3164 ◽  
Author(s):  
Siu Ling Lam ◽  
Shane Kirby ◽  
Anthony B. Schryvers
Keyword(s):  
Haemophilus Influenzae ◽  
Functional Expression ◽  
Signal Peptides ◽  
Gram Negative Bacteria ◽  
Phenotypic Characteristics ◽  
Gram Negative ◽  
Periplasmic Proteins ◽  
Iron Binding Protein ◽  
Hybrid Genes ◽  
Iron Utilization

To study the periplasmic branch of iron (ferric ion) uptake systems in Gram-negative bacteria, genetic reconstitution experiments were initiated in Haemophilus influenzae involving exchange of the periplasmic iron-binding protein. The expression of many of the heterologous periplasmic ferric-binding proteins (FbpAs) was quite limited. Transformation experiments with the fbpA gene from Neisseria gonorrhoeae yielded two colony sizes with different phenotypic characteristics. The small colonies contained the intact N. gonorrhoeae fbpA gene and were deficient in utilization of transferrin iron. The large colonies contained hybrid H. influenzae/N. gonorrhoeae fbpA genes, were proficient in transferrin iron utilization and had enhanced levels of expression of FbpA. These hybrid genes included several that encoded the mature N. gonorrhoeae FbpA with the H. influenzae signal peptide. To more fully evaluate the effect of foreign signal peptides, a series of hybrid genes were prepared that exchanged the signal peptides from H. influenzae FbpA, N. gonorrhoeae FbpA and the TEM-1 β-lactamase. The presence of the H. influenzae leader was required for functional expression of FbpAs and was shown to dramatically increase the level of β-lactamase activity.

scholarly journals Critical role of the periplasm in copper homeostasis in Gram-negative bacteria

2020 ◽  
Author(s):  
Jun-ichi Ishihara ◽  
Tomohiro Mekubo ◽  
Chikako Kusaka ◽  
Suguru Kondo ◽  
Hirofumi Aiba ◽  
...  
Keyword(s):  
Critical Role ◽  
Copper Homeostasis ◽  
Efflux Pumps ◽  
Ecological Niches ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Gram Negative ◽  
Wide Range ◽  
Periplasmic Proteins

AbstractCopper is essential for life, but is toxic in excess; that is, cells must keep an optimal internal copper concentration. Under aerobic conditions, less toxic Cu(II) taken up by bacterial cells is reduced to more toxic Cu(I) in the cytoplasm. Copper homeostasis is achieved in the cytoplasm and the periplasm as a unique feature of Gram-negative bacteria. The copper efflux pumps, CopA and CusCBA export Cu(I) from the cytoplasm or the periplasm to outside of the cells in Escherichia coli. In addition, the periplasmic proteins, such as a multi-copper oxidase CueO, play a role in the periplasmic detoxification. While the efflux pumps are highly conserved in Gram-negative bacteria, the periplasmic proteins are diversified, indicating that copper homeostasis in the periplasm could contribute to adaptation to various living environments. However, the role of the periplasm and periplasmic proteins in regard to whole-cell copper homeostasis remains unknown. In this study, we addressed the role of the periplasm and periplasmic proteins in copper homeostasis to adapt to various ecological niches. We have used a systems approach, alternating rounds of experiments and models, to further elucidate the dynamics of copper efflux system. We measured the response to copper of the main specific copper export systems in the wild type E. coli strain, and a series of deletion mutant strains. We interpreted these data using a detailed mathematical model and Bayesian model fitting routines, and verified copper homeostasis. Compared with the simulation and the growth in response to copper, we found that the growth was associated with copper abundance in the periplasm. In particular, CueO unique to Gram-negative bacteria contributes both to protection against Cu(I) toxicity and to incorporating copper into the periplasmic components/proteins, resulting in maximizing the growth. These results suggest that Gram-negative bacteria have evolved to utilize the periplasm as a sensor and store for copper, in order to enable Gram-negative bacteria to adapt to a wide range of environmental copper concentrations.

Optimization of a lysis method to isolate periplasmic proteins from Gram‐negative bacteria for clinical mass spectrometry

2021 ◽  
pp. 2100044
Author(s):  
Dong Huey Cheon ◽  
Saeyoung Lee ◽  
Won Suk Yang ◽  
Seohyun Hwang ◽  
Heejung Jang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Periplasmic Proteins

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.

Neutrophil pseudoplatelets in subgingival plaque and crevicular fluid samples from periodontal diseased sites

1989 ◽  
Vol 47 ◽  
pp. 862-863 ◽  
Author(s):  
J Hanker ◽  
E.J. Burkes ◽  
G. Greco ◽  
R. Scruggs ◽  
B. Giammara
Keyword(s):  
Electron Microscopy ◽  
Bone Marrow ◽  
Peripheral Blood ◽  
Gingival Crevicular Fluid ◽  
Light And Electron Microscopy ◽  
Subgingival Plaque ◽  
Staining Reaction ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Crevicular Fluid

The mature neutrophil with a segmented nucleus (usually having 3 or 4 lobes) is generally considered to be the end-stage cell of the neutrophil series. It is usually found as such in the bone marrow and peripheral blood where it normally is the most abundant leukocyte. Neutrophils, however, must frequently leave the peripheral blood and migrate into areas of infection to combat microorganisms. It is in such areas that neutrophils were first observed to fragment to form platelet-size particles some of which have a nuclear lobe. These neutrophil pseudoplatelets (NPP) can readily be distinguished from true platelets because they stain for neutrophil myeloperoxidase. True platelets are not positive in this staining reaction because their peroxidase Is inhibited by glutaraldehyde. Neutrophil pseudoplatelets, as well as neutrophils budding to form NPP, could frequently be observed in peripheral blood or bone marrow samples of leukemia patients. They are much more prominent, however, in smears of inflammatory exudates that contain gram-negative bacteria and in gingival crevicular fluid samples from periodontal disease sites. In some of these samples macrophages ingesting, or which contained, pseudoplatelets could be observed. The myeloperoxidase in the ingested pseudoplatelets was frequently active. Despite these earlier observations we did not expect to find many NPP in subgingival plaque smears from diseased sites. They were first seen by light microscopy (Figs. 1, 3-5) in smears on coverslips stained with the PATS reaction, a variation of the PAS reaction which deposits silver for light and electron microscopy. After drying replicate PATS-stained coverslips with hexamethyldisilazane, they were sputter coated with gold and then examined by the SEI and BEI modes of scanning electron microscopy (Fig. 2). Unstained replicate coverslips were fixed, and stained for the demonstration of myeloperoxidase in budding neutrophils and NPP. Neutrophils, activated macrophages and spirochetes as well as other gram-negative bacteria were also prominent in the PATS stained samples. In replicate subgingival plaque smears stained with our procedure for granulocyte peroxidases only neutrophils, budding neutrophils or NPP were readily observed (Fig. 6).

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