scholarly journals DegP Initiates Regulated Processing of Filamentous Hemagglutinin in Bordetella bronchiseptica

mBio ◽  
2021 ◽  
Author(s):  
Richard M. Johnson ◽  
Zachary M. Nash ◽  
Margaret R. Dedloff ◽  
John C. Shook ◽  
Peggy A. Cotter
Keyword(s):  
Bacterial Pathogenesis ◽  
Bordetella Bronchiseptica ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Filamentous Hemagglutinin

Two-partner secretion (TPS) systems are broadly distributed among Gram-negative bacteria and play important roles in bacterial pathogenesis. FhaB-FhaC is the prototypical member of the TPS family and we here identified the protease that initiates a processing cascade that controls FhaB function.

scholarly journals Nontraditional Antibiotics—Challenges and Triumphs

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 169
Author(s):  
Karl A. Hansford
Keyword(s):  
Bacterial Pathogenesis ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Important Means

The pursuit of nontraditional antibiotics is becoming an increasingly important means to tackle seemingly insurmountable challenges faced by contemporary antibiotic researchers as they overcome the shifting landscape of bacterial pathogenesis, particularly for Gram-negative bacteria [...]

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.

scholarly journals From DNA Damage to Cancer Progression: Potential Effects of Cytolethal Distending Toxin

2021 ◽  
Vol 12 ◽  
Author(s):  
Yi-Ru Lai ◽  
Yu-Fang Chang ◽  
Jason Ma ◽  
Cheng-Hsun Chiu ◽  
Ming-Ling Kuo ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cancer Progression ◽  
Therapeutic Strategies ◽  
Bacterial Pathogenesis ◽  
Cancer Development ◽  
Cytolethal Distending Toxin ◽  
Gram Negative Bacteria ◽  
Gram Negative

Cytolethal distending toxin (CDT), one of the most important genotoxins, is produced by several gram-negative bacteria and is involved in bacterial pathogenesis. Recent studies have shown that bacteria producing this peculiar genotoxin target host DNA, which potentially contributes to development of cancer. In this review, we highlighted the recent studies focusing on the idea that CDT leads to DNA damage, and the cells with inappropriately repaired DNA continue cycling, resulting in cancer development. Understanding the detailed mechanisms of genotoxins that cause DNA damage might be useful for targeting potential markers that drive cancer progression and help to discover new therapeutic strategies to prevent diseases caused by pathogens.

scholarly journals Outer Membrane Vesicles (OMVs) Produced by Gram-Negative Bacteria: Structure, Functions, Biogenesis, and Vaccine Application

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Noemi Furuyama ◽  
Marcelo Palma Sircili
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicles ◽  
Structure Functions ◽  
Bacterial Pathogenesis ◽  
Outer Membrane Vesicles ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
The Future

Gram-negative bacteria produce outer membrane vesicles (OMVs) with 10 to 300 nm of diameter. The contribution of OMVs to bacterial pathogenesis is a topic of great interest, and their capacity to be combined with antigens impact in the future to the development of vaccines.

scholarly journals Evaluation of the API 20E system for identification of nonfermentative Gram-negative bacteria

1978 ◽  
Vol 7 (6) ◽  
pp. 539-545 ◽  
Author(s):  
M Shayegani ◽  
P S Maupin ◽  
D M McGlynn
Keyword(s):  
Data Base ◽  
Conventional Method ◽  
Close Agreement ◽  
Acinetobacter Calcoaceticus ◽  
Bordetella Bronchiseptica ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Complete Identification

The API 20E system for Enterobacteriaceae, recently broadened to include identification of nonfermentative gram-negative bacteria, was evaluated and compared with the conventional method for complete identification of 221 nonfermenters, which were well distributed into 48 species or biotypes and included organisms not listed in the API 20E data base. The results of 16 tests common to both systems were in close agreement. The API 20E system correctly identified 71 (43%) of the 165 organisms included in the API 20E data base. However, almost 90% of Acinetobacter calcoaceticus, three species of Pseudomonas, and Bordetella bronchiseptica were correctly identified to species.

scholarly journals Identification and Cloning of waaF (rfaF) from Bordetella pertussis and Use To Generate Mutants ofBordetella spp. with Deep Rough Lipopolysaccharide

1998 ◽  
Vol 180 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Andrew G. Allen ◽  
Tomoko Isobe ◽  
Duncan J. Maskell
Keyword(s):  
Amino Acid ◽  
Bordetella Pertussis ◽  
Inner Core ◽  
Sequence Similarity ◽  
Bordetella Bronchiseptica ◽  
Amino Acid Sequence Similarity ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bordetella Parapertussis ◽  
Allelic Exchange

ABSTRACT A DNA locus from Bordetella pertussis capable of reconstituting lipopolysaccharide (LPS) O-antigen biosynthesis inSalmonella typhimurium SL3789 (rfaF511) has been isolated, by using selection with the antibiotic novobiocin. DNA within the locus encodes a protein with amino acid sequence similarity to heptosyltransferase II, encoded by waaF (previouslyrfaF) in other gram-negative bacteria. Mutation of this gene in B. pertussis, Bordetella parapertussis, and Bordetella bronchiseptica by allelic exchange generated bacteria with deep rough LPS phenotypes consistent with the proposed function of the gene as an inner core heptosyltransferase. These are the first LPS mutants generated in B. parapertussis andB. bronchiseptica and the first deep rough mutants of any of the bordetellae.

scholarly journals Evaluation of the Oxi/Ferm tube system for identification of nonfermentative Gram-negative bacilli

1978 ◽  
Vol 7 (6) ◽  
pp. 533-538
Author(s):  
M Shayegani ◽  
A M Lee ◽  
D M McLynn
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Close Agreement ◽  
Acinetobacter Calcoaceticus ◽  
Bordetella Bronchiseptica ◽  
Gram Negative Bacteria ◽  
Conventional System ◽  
Tube System ◽  
Gram Negative ◽  
Complete Identification ◽  
Test Organisms

The Oxi/Ferm tube system designed for identification of oxidative-fermentative gram-negative bacteria was evaluated for identification of nonfermentative gram-negative bacilli by comparing it with the conventional system. The nine biochemical reactions used as the initial tests in the Oxi/Ferm tube system showed a close agreement with the same conventional reactions. However, the system was only 41% accurate to species or biotype for complete identification of 239 isolates which were well distributed in 48 species and biotypes and included organisms not listed in the Oxi/Ferm tube identification list. The system correctly identified 56% of the test organisms when the degree of identification was based on the manufacturer's guidance list. However, all isolates of Acinetobacter calcoaceticus, Bordetella bronchiseptica, Pseudomonas aeruginosa, P. diminuta, and group IIf were completely identified by the system.

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.

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