a nurse is caring for a client who has pharyngeal diphtheria This is a topic that many people are looking for. star-trek-voyager.net is a channel providing useful information about learning, life, digital marketing and online courses …. it will help you have an overview and solid multi-faceted knowledge . Today, star-trek-voyager.net would like to introduce to you Corynebacterium diphtheriae – causes, symptoms, diagnosis, treatment, pathology. Following along are instructions in the video below:
Medicine is hard work osmosis makes it easy. Corynebacterium diphtheriae. Or just cdiphtheriae takes.
Its. Its. Name from the greek coryne that means club and diphtheria .
Which means so to sum this up c. Diphtheria is a club looking bacteria that causes diphtheria an infection with a characteristic tough leathery membrane that forms in the pharynx. C.
Diphtheria. Has four main subspecies c. Diphtheria.
Mitis. C. Diphtheria.
Intermedius. C. Diphtheria.
Gravis. And c. Diphtheria.
Belfanti. Alright. Now c.
Diphtheria has a thick peptidoglycogen cell wall that takes in purple dye. When graham stained so its a gram positive bacteria.
Its aerobic which means that it requires oxygen to grow and it does not form spores. Now when stained with alberts stain. These bacteria demonstrate some unique features they look like green club shaped bacteria with metachromatic granules.
Which are these dark blue dots made of phosphate located at the bacterial poles. When there are a lot of them clustered together these bacteria seem to be arranged in a characteristic pattern that resembles chinese letters finally c. Diphtheria is a fastidious bacteria this means that it can only grow on special.
Nutrients. Enriched media. The medium commonly used to grow.
This bug is cysteine tellurite blood agar on which see diphtheria grown to black colonies alright. Any of the c diphtheriae subspecies can be either toxigenic or not depending on whether or not they produce the diphtheria toxin or dt for short dt is a cytotoxic protein. Where cytotoxic means it causes damage to host cells.
In fact. All the c diphtheriae subspecies start out as non toxigenic. But they become toxigenic after theyre infected by a beta bacteriophage.
This is a kind of virus that attaches the bacteria and merges into its own genome with the bacteria the beta bacteriophage genome. Contains tox genes which code for diphtheria toxin production. Following this c diphtheriae can make dt.
And in turn caused. Diphtheria. Now.
Dt has two main subunits. A and b. Joined by a disulfide bond with each of the subunits playing a specific role in the invasion and destruction to the host cells the b sub unit.
Which is the bigger portion of dt complex helps binding to the host cell membrane after attaching to the host cells. The whole dt complex gets slowly engulfed by the cell membrane.
Which invaginates to form a sac on its inner side. The sack then separates from the actual cell. Membrane forming a vesicle called an endosome within the host cell cytoplasm.
The medium inside the endosome becomes more acidic and as a consequence. The disulfide bond holding the two subunits together becomes weak and eventually break separating the subunits the a subunit then diffuses through the endosome membrane into the cytoplasm where it goes straight to the ribosomes here it interferes with cell protein synthesis this happens. Because the a subunit has an adp ribose group which attaches to the elongation factor ef2 an important ribosomal protein that joins amino acids together during protein synthesis.
This process is called ef2 adp ribosylation and it results in complete deactivation of the ef2. Which stops protein synthesis leading to cell death. Alright now c.
Diphtheriae. Mainly causes diphtheria in unvaccinated or immunocompromised. People.
Most often the bacteria can be transmitted from one person to another mainly by respiratory droplets. Following coughing or sneezing in which cases causes pharyngeal diphtheria. But they can also enter the body through open lesions on the skin causing cutaneous diphtheria.
Following inhalation of infected respiratory droplets c. Diphtheriae attaches to the pharyngeal epithelial cells. Where they release dt toxin this causes local inflammation that leads to necrosis of pharyngeal tissue and neck swelling.
The necrosis tissue builds up over the pharynx and larynx forming a gray adherent leathery membrane. Commonly referred to as a pseudomembrane in some cases. A portion of the pseudomembrane can detach and get lodged in the trachea or bronchi and when its big enough it can block the airways completely causing death by asphyxiation if left untreated the bacteria gradually invades deeper into the pharyngeal wall until it reaches the bloodstream from where it can move to distant organs.
Like the heart causing myocarditis or inflammation of the heart muscle or the kidneys causing acute tubular necrosis or destruction to the renal tubules c. Diphtheriae can also travel to the nerves causing nerve demyelination meaning they destroy the myelin sheath covering the nerve axons which leads to polyneuropathy diphtheria polyneuropathy usually affects the oculomotor nerve causing oculomotor palsy meaning the muscles that move the eyes are impaired. It can also affect the phrenic nerve.
Which innervates the diaphragm and in this case. It may cause trouble breathing regardless of the affected system.
People. With diphtheria infection. Present with symptoms of low grade fever.
General malaise and weakness in pharyngeal diphtheria. People. Present with sore throat.
A swollen neck. That people commonly called bull neck and the pharyngeal pseudomembrane formation that usually can cause difficulty breathing associated with respiratory wheezes or stridor in cutaneous diphtheria. There are typically chronic skin ulcers which are shallow with myocarditis there might be signs of cardiac dysfunction like arrhythmias or even heart failure.
Which is when the heart cant pump enough blood to meet the bodys demands with acute tubular necrosis. There may be oliguria. Which is decreased urine production with oculomotor palsy.
There may be diplopia. Which means double vision or the person might not be able to move their eyes up down or to the side diagnosing diphtheria is mainly done by cultures of swabs from the pharynx or the suspected skin lesion to isolate c diphtheria. When the culture gets positive next.
You want to figure out the c diphtheriae strain in question is toxic organic. This is done by eleks test. In which c.
Diphtheria is grown on an agar plate thats embedded with an antitoxin impregnated filter paper. If the strain makes dt. The toxin reacts with the antitoxin resulting in bands of visible precipitations.
Another method consists of detecting. The bacterias toxigenicity in its dna. Using polymerase chain.
Reaction or pcr. The treatment for diphtheria starts right upon clinical suspicion.
Even before diagnostic confirmation. It starts with isolating. The patient to prevent further spread and then penicillin g.
Is given or erythromycin in case of allergy. Then if the infecting bacteria is proven to be toxigenic with eleks test diphtheria antitoxin is given to counter the effects of the bacterial toxin. Luckily theres a vaccine to prevent diphtheria this vaccine consists of a toxoid.
Which is a modified dt with the ability to activate the immune system and make it ready to tackle a real infection. Without causing damage to tissues c. Diphtheria.
Toxoid is usually combined with other vaccines typically tetanus pertussis and whooping cough vaccines. Together called the dtap given to children between 2 months to 6 years of age all right as a quick recap corynebacterium diphtheriae is a gram positive club shaped bacteria that causes diphtheria infection. It is non motile aerobic non spore forming and it has metachromatic granules when stained with alberts stain when infected by a beta bacteriophage c.
Diphtheriae. Becomes toxigenic. So it starts to produce diphtheria toxin.
Which causes tissue destruction and inflammation diphtheria can present as pharyngeal or cutaneous diphtheria with pharyngeal diphtheria. A pseudomembrane forms over the pharynx and the larynx and it might detach and cause airway obstruction. Sometimes the bacteria can spread to other places.
Such as the heart resulting in diphtheria myocarditis. The kidneys resulting in acute tubular necrosis or even nerves resulting in diphtheria polyneuropathy with cutaneous diphtheria. There are chronic shallow skin ulcers.
The diagnosis depends on cultures. But treatment with penicillin g or erythromycin can be initiated upon clinical suspicion. Diphtheria antitoxin.
Is also given for toxigenic strains. .
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