Is pertussis Gram-negative or gram positive?

Bordetella pertussis is a small (approximately 0.8 μm by 0.4 μm), rod-shaped, coccoid, or ovoid Gram-negative bacterium that is encapsulated and does not produce spores. It is a strict aerobe.

Which Gram-negative Betaproteobacteria is responsible for pertussis?

The primary causative agent, Bordetella pertussis, is a Gram-negative bacterium that was first described by Bordet and Gengou in 1906 2. The closely related bacterium Bordetella parapertussisHu is responsible for a minority of cases (approximately 14%) and is less capable of causing severe disease3. Both B.

Is B. pertussis Gram positive?

Bordetella pertussis is a Gram-negative, aerobic, pathogenic, encapsulated coccobacillus of the genus Bordetella, and the causative agent of pertussis or whooping cough.

What is pertactin in pertussis?

Pertactin is a virulence toxin of Bordetella pertussis and close relatives, such as Bordetella parapertussis. It is an outer surface membrane protein involved in the binding of B. pertussis to host cells, which aids the bacteria in infection of host cells with whooping cough.

Why is Bordetella pertussis Gram-negative?

pertussis is a very small Gram-negative aerobic coccobacillus that appears singly or in pairs. Its metabolism is respiratory, never fermentative, and taxonomically, Bordetella is placed among the “Gram-negative Aerobic Rods and Cocci” in Bergey’s Manual. Bordetella is not assigned to any family.

What bacteria is Gram-negative coccobacilli?

The Gram-negative coccobacilli, Haemophilus influenza can cause a variety of infections, including meningitis, an infection that results in inflammation of the brain and spinal cord, as well as pneumonia, an infection of the lungs.

What does Gram-negative mean in bacteria?

Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation.

What does tracheal cytotoxin do?

The tracheal cytotoxin is a cell wall peptidoglycan fragment and cannot be classified as an exotoxin or an endotoxin. The toxin kills ciliated epithelial cells in the respiratory tract and stimulates the release of interleukin 1 (IL-1), which acts as an endogenous pyrogen.

What does filamentous hemagglutinin do?

Filamentous hemagglutinin (FHA) is a cell surface protein of Bordetella pertussis which functions as an adhesin for this organism. It is a component of many new acellular pertussis vaccines. The proposed role of FHA in immunity to pertussis is based on animal studies which have produced some conflicting results.

Is Bordetella pertussis a bacilli or cocci?

B. pertussis is a very small Gram-negative aerobic coccobacillus that appears singly or in pairs. Its metabolism is respiratory, never fermentative, and taxonomically, Bordetella is placed among the “Gram-negative Aerobic Rods and Cocci” in Bergey’s Manual.

What is gram-negative extracellular Diplococci?

Neisseria gonorrhoeae is a Gram negative, coffee-bean shaped intracellular diplococcus bacterium responsible for gonorrhoea which is one of the classical sexually transmitted infections (STIs) [1]. The causative organism is highly adapted to the genital tract and often causing asymptomatic and undetected infection [2].

Why is it called gram-negative?

In 1884, a bacteriologist named Christian Gram created a test that could determine if a bacterium had a thick, mesh-like membrane called peptidoglycan. Bacteria with thick peptidoglycan are called gram positive. If the peptidoglycan layer is thin, it’s classified as gram negative.

What is the difference between gram-negative and gram positive?

Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide. Gram-positive bacteria lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in the Gram-negatives.

Is tracheal cytotoxin a virulence factor of Bordetella pertussis?

Tracheal cytotoxin (TCT) is the only virulence factor produced by B. pertussis that has been able to recapitulate this pathology in animal models. This pathophysiology is well characterized in a hamster tracheal model, but human data are lacking due to scarcity of donor material.

How does tracheal cytotoxin benefit Bordetella pertussis?

Bordetella, Infection And Immunity pertussis have been demonstrated to suppress the normal responses of the host to pertussis in vitro and in vivo. TCT, by destruction of ciliated epithelial cells, impedes clearance of bacteria, mucus and debris from airways.

What is a function of the B pertussis rod like protein filamentous hemagglutinin FHA in pathogenicity?

Filamentous hemagglutinin (FHA) is a large (>200 kDa), rod-shaped protein expressed by bordetellae that is both surface-associated and secreted. FHA mediates bacterial adherence to epithelial cells and macrophages in vitro and is absolutely required for tracheal colonization in vivo.

What is FHA in pertussis?

Monoclonal Antibodies Against Bordetella pertussis Filamentous Hemagglutinin (FHA) Protein. Filamentous hemagglutinin (FHA) is one of the major adhesion molecules of Bordetella pertussis, a bacterial infection that causes whopping cough. Once thought to be primarily a childhood disease, B.

Which type of bacteria are gram-negative diplococci with adjacent sides flattened?

Neisseria species are Gram-negative cocci, 0.6 to 1.0 μm in diameter. The organisms are usually seen in pairs with the adjacent sides flattened.

Is gonorrhea gram-negative diplococci?

Summary. Gonorrhea infection is a common STI caused by Neisseria gonorrhoeae, a gram-negative diplococcus bacterium that is closely related to other human Neisseria species. Men typically present with a urethral discharge; women are often asymptomatic, but may have vaginal discharge.