scholarly journals An orphancbb3-type cytochrome oxidase subunit supportsPseudomonas aeruginosabiofilm growth and virulence

2017 ◽  
Author(s):  
Jeanyoung Jo ◽  
Krista L. Cortez ◽  
William C. Cornell ◽  
Alexa Price-Whelan ◽  
Lars E.P. Dietrich
Keyword(s):  
Caenorhabditis Elegans ◽  
Cytochrome Oxidase ◽  
Opportunistic Pathogen ◽  
Bacterial Pathogenesis ◽  
Catalytic Subunit ◽  
Cytochrome Oxidase Subunit ◽  
Unique Role ◽  
High Affinity ◽  
Biofilm Model ◽  
Biofilm Development

ABSTRACTHypoxia is a common challenge faced by bacteria during associations with hosts due in part to the formation of densely packed communities (biofilms).cbb3-type cytochromecoxidases, which catalyze the terminal step in respiration and have a high affinity for oxygen, have been linked to bacterial pathogenesis. The pseudomonads are unusual in that they often contain multiple full and partial (i.e., “orphan”) operons forcbb3-type oxidases and oxidase subunits. Here, we describe a unique role for the orphan catalytic subunit CcoN4 in colony biofilm development and respiration in the opportunistic pathogenP. aeruginosaPA14. We also show that CcoN4 contributes to the reduction of phenazines, antibiotics that support redox balancing for cells in biofilms, and to virulence in aCaenorhabditis elegansmodel of infection. These results highlight the relevance of the colony biofilm model to pathogenicity and underscore the potential ofcbb3-type oxidases as therapeutic targets.

scholarly journals An orphan cbb3-type cytochrome oxidase subunit supports Pseudomonas aeruginosa biofilm growth and virulence

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jeanyoung Jo ◽  
Krista L Cortez ◽  
William Cole Cornell ◽  
Alexa Price-Whelan ◽  
Lars EP Dietrich
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cytochrome C ◽  
Opportunistic Pathogen ◽  
Bacterial Pathogenesis ◽  
Cytochrome Oxidase Subunit ◽  
Biofilm Growth ◽  
Unique Role ◽  
High Affinity ◽  
Biofilm Model ◽  
Biofilm Development

Hypoxia is a common challenge faced by bacteria during associations with hosts due in part to the formation of densely packed communities (biofilms). cbb3-type cytochrome c oxidases, which catalyze the terminal step in respiration and have a high affinity for oxygen, have been linked to bacterial pathogenesis. The pseudomonads are unusual in that they often contain multiple full and partial (i.e. ‘orphan’) operons for cbb3-type oxidases and oxidase subunits. Here, we describe a unique role for the orphan catalytic subunit CcoN4 in colony biofilm development and respiration in the opportunistic pathogen Pseudomonas aeruginosa PA14. We also show that CcoN4 contributes to the reduction of phenazines, antibiotics that support redox balancing for cells in biofilms, and to virulence in a Caenorhabditis elegans model of infection. These results highlight the relevance of the colony biofilm model to pathogenicity and underscore the potential of cbb3-type oxidases as therapeutic targets.

Recombinant R2-pyocin cream is effective in treating Pseudomonas aeruginosa-infected wounds

2021 ◽  
Author(s):  
Abdulaziz Alqahtani ◽  
London Mena ◽  
Dean Scholl ◽  
Cassandra Kruczek ◽  
Jane A. Colmer-Hamood ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Chronic Wounds ◽  
Opportunistic Pathogen ◽  
Biofilm Model ◽  
Major Species ◽  
Infected Wounds ◽  
New Antibiotics ◽  
Biofilm Development ◽  
Antibiofilm Agents

<i>Pseudomonas aeruginosa</i>, a Gram-negative opportunistic pathogen, is one of the major species isolated from infected chronic wounds. The multidrug resistance exhibited by <i>P. aeruginosa</i> plus its ability to form biofilms that are difficult to eradicate, along with rising cost of producing new antibiotics, has necessitated the search for alternatives to standard antibiotics. Pyocins are antimicrobial compounds produced by P. aeruginosa to protect itself from competitors. We synthesized and purified recombinant <i>P. aeruginosa</i> R2 pyocin and used it in aqueous solution (rR2P) or formulated in polyethylene glycol (rR2PC) to treat P. aeruginosa-infected wounds. Clinical strains of <i>P. aeruginosa</i> were found to be sensitive (completely), partially sensitive, or resistant to rR2P. In the in vitro biofilm model, rR2P inhibited biofilm development by rR2P-sensitive isolates; while rR2PC eliminated partial biofilms formed by these strains in the in vitro wound biofilm model. In the murine model of excision wound, and at 24 h post infection, rR2PC application significantly reduced the bioburden of clinical isolate BPI86. Application of rR2PC containing two glycoside hydrolase antibiofilm agents eliminated BPI86 from the infected wound. These results suggest that the topical application of rR2PC is an effective therapy to treat wounds infected with R2P-senstive P. aeruginosa strains.

First record of body colour polymorphism in giant African snail Achatina fulica (Bowdich, 1822) - a comparative study using mitochondrial cytochrome oxidase subunit I (COI) gene

ENTOMON ◽  
2019 ◽  
Vol 44 (2) ◽  
pp. 155-160
Author(s):  
Keerthy Vijayan ◽  
R. Sugantha Sakthivel ◽  
T.V. Sajeev
Keyword(s):  
Cytochrome Oxidase ◽  
South India ◽  
The Body ◽  
Colour Polymorphism ◽  
Coi Gene ◽  
Body Colour ◽  
Cytochrome Oxidase Subunit ◽  
Cytochrome Oxidase Subunit I ◽  
Black And White ◽  
Oxidase Subunit

The presence of the body colour polymorphism in the tropical invasive pest giant African snail is reported for the first time from South India. Three different body colour polymorphs were recognised viz. grey, black and white. The grey body colour is the most common polymorph. The black and white colour polymorphs are found to be in almost equal proportions in the reported localities with the grey counterparts. The cytochrome oxidase subunit I (COI) sequences of the three colour polymorphs are found to be identical. The presence of the body colour polymorphism in south India may be attributed to the avian predation and other selection pressures.

The Caenorhabditis elegans odr-2 Gene Encodes a Novel Ly-6-Related Protein Required for Olfaction

Genetics ◽  
2001 ◽  
Vol 157 (1) ◽  
pp. 211-224 ◽  
Author(s):  
Joseph H Chou ◽  
Cornelia I Bargmann ◽  
Piali Sengupta
Keyword(s):  
Caenorhabditis Elegans ◽  
Motor Neurons ◽  
Amino Terminus ◽  
Signaling Proteins ◽  
Related Protein ◽  
Olfactory Neurons ◽  
Unique Role ◽  
C Elegans ◽  
Founding Member ◽  
High Concentrations

Abstract Caenorhabditis elegans odr-2 mutants are defective in the ability to chemotax to odorants that are recognized by the two AWC olfactory neurons. Like many other olfactory mutants, they retain responses to high concentrations of AWC-sensed odors; we show here that these residual responses are caused by the ability of other olfactory neurons (the AWA neurons) to be recruited at high odor concentrations. odr-2 encodes a membrane-associated protein related to the Ly-6 superfamily of GPI-linked signaling proteins and is the founding member of a C. elegans gene family with at least seven other members. Alternative splicing of odr-2 yields three predicted proteins that differ only at the extreme amino terminus. The three isoforms have different promoters, and one isoform may have a unique role in olfaction. An epitope-tagged ODR-2 protein is expressed at high levels in sensory neurons, motor neurons, and interneurons and is enriched in axons. The AWC neurons are superficially normal in their development and structure in odr-2 mutants, but their function is impaired. Our results suggest that ODR-2 may regulate AWC signaling within the neuronal network required for chemotaxis.

scholarly journals In Vitro Anti-Biofilm and Antibacterial Properties of Streptococcus downii sp. nov.

2021 ◽  
Vol 9 (2) ◽  
pp. 450
Author(s):  
Maigualida Cuenca ◽  
María Carmen Sánchez ◽  
Pedro Diz ◽  
Lucía Martínez-Lamas ◽  
Maximiliano Álvarez ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Quantitative Polymerase Chain Reaction ◽  
Bacterial Load ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Oral Bacteria ◽  
Periodontal Pathogens ◽  
Biofilm Model ◽  
Biofilm Development

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.

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