Pneumonia

“Pneumonia is called the old man’s friend because, left untreated, the sufferer often lapses into a state of reduced consciousness, slipping peacefully away in their sleep, giving a dignified end to a period of often considerable suffering.” -Dr John Pillinger

Pneumonia is a major cause of morbidity and mortality worldwide, the 6th largest cause of death in the USA. It is also economically costly in antibiotics, time off work, and hospitalisation

In half the cases the cause is not identified

In those where a cause is identified, S. pneumoniae is the most common cause

The reservoir is usually humans (oneself or a contact)

spread is through respiratory droplets

Community acquired eg Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, Chlamydia pneumoniae

Noscomial (hospital acquired) eg Enterobacteriaceae, Staphylococcus aureus, Anaerobes, Pseudomonas aeruginosa

Many patients have an underlying condition, e.g. bronchitis, asthma, a viral infection, tumours

Characterised by the alveolar sacs filling up with pus, giving rise to a purulent sputum

Symptoms

Results in chest tightness or pain, difficulty in breathing, fever or hypothermia, reduced blood oxygen, coughing to clear mucus, chest will sound “dull” when tapped, tachypnea, tachycardia (>100 bpm) or bradycardia (< 60 bpm), central cyanosis, altered mental status.

Streptococcus pneumoniae: Rust-colored sputum

Pseudomonas, Haemophilus, and pneumococcal species: May produce green sputum

Klebsiella species pneumonia: Red currant-jelly sputum

Anaerobic infections: Often produce foul-smelling or bad-tasting sputum

Diagnosis

X-ray showing infiltrates

Elevated temperature

Changes in WBC counts

Culture confirmation

Serum chemistry panel

Arterial/venous blood gas

Serum free cortisol value and lactate level

Treatment

Intensive treatment, potentially to ITU level

Tailored antimicrobials if possible - limited options with viruses

Treatments include: analgesia and antipyretics, physiotherapy, bronchodilators and N-acetylcysteine, suctioning and bronchial hygiene, ventilation

Pathogenesis

Causative agents can enter the lungs through inhalation, aspiration, spread across mucous membrane (some viruses), haematogenous spread (occasionally, e.g. IV drug users with S. aureus septicaemia) and penetrating injury (rare).

Immune response is triggered in the lung and there are local defence factors in the respiratory secretions

Cilia, if functioning, will move material up the respiratory tract, but if damaged this physical defence is impaired

The lungs also have a resident macrophage population (alveolar macrophages) but they are of limited use against several respiratory pathogens that possess a capsule

some organisms can even replicate in these cells

Damage to the lung is caused by the microbes and the immune response

Enzymes released by the bacteria

Factors released by immune cells that cause local irritation and cell apoptosis

Systemic manifestations follow eg

Oxygen deprivation – thickening of the membranes reduces gas transfer

Systemic shock – especially with Gram-negative bacilli such as Haemophilus influenzae

How to remember Lysteria monocytogenes tumbling motility?

MICROBIOLOGY MNEMONIC

So, Lysteria rhymes with Hysteria, and when I think of hysteria I think of someone dancing Hysterically…..(actually, me dancing hysterically..)

I also googled Hysteria, and found this:

HYSTERIA RADIO!

So here it goes: “Lysteria dances to Hysteria Radio”

If I don’t come up with all these silly associations my brain melts and confuses all the freakin bacterias, so bear with me…

9 notes View Post

t-b-a-blr-blog

6 years ago

Killed, inactivated Vaccines Available in the US

Killed vaccines induce only HUMORAL immunity

RIP ACE

R abies

I nfluenza (injected)

P olio (salk)

A Hepatitis

C holera

E ncephalitis viruses (eg Japanese encephalitis)

44 notes View Post

t-b-a-blr-blog

6 years ago

Microbio lab work 📖

378 notes View Post

t-b-a-blr-blog

6 years ago

study tip request: studying on public transport (or sth related like how to know what to record when you record yourself saying notes so that you can listen to them on public transport)

Best Way to Make Study Recordings for Yourself

Testing yourself is the most effective way to learn a topic, so this one is fairly straightforward. For recording:

Formulate an examination style question, and run through the answer in your head, organising your thoughts.

Then record the question, and mouth silently the answer fluently (reason being that just thinking in your head may result in too little or too much silence.

Leave a few extra seconds of silence for thinking time (~3-5 seconds).

Answer the question aloud in the recording (I’d suggest a brief one)

Rinse and repeat until you have enough to last you the whole commute.

Hope that helps! For more tips on how to spend time on commutes, check out my post on Staying Productive No Matter How Much Time You Have :)

Study Tip Request: Studying On Public Transport (or Sth Related Like How To Know What To Record When

250 notes View Post

t-b-a-blr-blog

6 years ago

Recurrente infections with catalase positive organisms in Chronic Granulomatose Disease (CGD)

30 notes View Post

t-b-a-blr-blog

6 years ago

My revised pnemonic for ADP ribosylation A-B toxins

Boring and serious people score high in usmle…

Bordetella pertussis and B.cereus increases cAMP by inhibiting Gi

Cool and Vibrant people also score high…

E. coli and Vibreo cholerae increases cAMP by activating Gs

Exception: Please please please remember that Bacillus anthracis has an edema factor which it self acts as adenylate cyclase…. no ADP ribosylation involved..so hence cAMP level increases.

16 notes View Post

t-b-a-blr-blog

6 years ago