Micro-organism series: Staphylococcus aureus

Hello awesomites here is our first bacteria of micro-organism series - Staphylococcus aureus

Morphology:
Aerobes and facultative anaerobes
Diameter: 1 micrometer
Gram profile: Gram positive Cocci
Arrangement: Grape like clusters
Motility: Non-motile
Sporeing or not: Non-sporing
Capsule: Usually capsulated. Non-capsulated strains have small amount of capsular material on the surface

Cultural characteristics:

Ordinary media: They grow readily with temperature range of 10-42°C ( Best at 37°C) and pH around 7.4 - 7.6

Nutrient agar:
You can remember how colony looks by the name STAPHYLOCOCCUS it self.
S - Smooth
O - Opaque
C - Circular
C - Convex
Easily emulsifiable.
It produces golden yellow pigment. Pigment production occurs best at 22℃ and only in aerobic culture. Growth represents "Oil-paint appearance".

Blood agar: Shows beta type of hemolysis when incubated under 20-25% carbon dioxide.

MacConkey agar: Pink colour small colonies (Because it ferments lactose!)

Selective media:
Ludlam's medium - Lithium chloride and tellurite.
Mannitol salt agar or salt milk agar- 1%Mannitol, 7.5%NaCl, Phenol red indicator.
Columbia colistin nalidixic acid agar.

Liquid media: Turbidity.

Biochemical Reactions:

Catalase : Positive
Oxidase : Negative
Mannitol: Positive
Indole: Negative
MR andVP: Positive
Phosphatase : Positive (Useful for screening as S epidermidis is negative or slightly positive )
Urease : Positive

Produces thermonuclease enzymes.

Virulence factors :
Extracellular enzymes :
Coagulase (Most virulent)
Lipase
Hyaluronidase
Staphylokinase

Toxins:

5 types of Cytolytic toxins: Alpha, Beta, Gamma, Delta and Leucocidins
Alpha: Most important hemolysin.
Beta: It is sphingomyelinase. Exhibits hot and cold phenomenon.
Leucocidin and gamma lysin is grouped under synergohymenotropic toxins.

9 types of enterotoxins: Responsible for staphylococcal food poisoning. Causes nausea, vomiting and diarrhoea within 2-6 hours.
A, B, C1, C2, C3, D, E, H and I.

Super antigens:

Toxic shock syndrome toxin (TSST)
Exfoliative
Enterotoxins
(What are superantigens and how do they work?)

Disease caused:
Remember " SOFT PENIS"
S - Skin infections
O - Osteomyelitis and arthritis
F - Food poisoning
T - Toxic shock syndrome
P - Pharyngitis and Pneumonia (Rarely)
E - Endocarditis
N - Necrotizing fascitis
I - Impetigo
S - Sepsis

Laboratory diagnosis:

Specimen and lesions

Pus - Suppurative lesions
Sputum - Respiratory Infections
Blood - Septicaemia
Urine - UTI
CSF- Meningitis
Faeces - Food poisoning

Collection and transport :
Sterile containers should be used
Sterile swabs for specimen from nose/perineum.

Direct microscopy :
Gram stained smears is useful in case of pus, cocci in clusters may be seen.

Treatment:
Sensitive to penicillin: Penicillin G is DOC (Drug of choice)
Penicillin allergy: Cefazolin is DOC
Methicillin resistant S.aureus: Vancomycin
Vancomycin resistant: S.aureus: Streptogramins, Linezolid, Telavancin.

That's all!
Finally done!
Stay awesome :)

~Khushboo shaikh,IkaN,and ojas

Submissions: Adverse effects of Glucocorticoids mnemonic

Adverse effects of GLUCOCORTICOIDS:

Mnemonic is glucocorticoids itself!

Introduction to micro-organism series

Hello awesomites!

We have started with micro-organism series where we will discuss bacterias and viruses. But before that let's have a little introduction of Gram positive bacteria and negative bacteria!

Fanconis anemia mnemonic

Hello!

Here's a post on Fanconis anemia!

Fact of the day: Factors that are lost in stored blood

Hello awesomites !

What happens to blood that is stored in blood bank ?

Pierre Robin Sequence mnemonic

Hey Awesomites

Pierre Robin Sequence is one of the most common causes of isolated cleft palate in the newborns. Here's the mnemonic for the triad of symptoms- PRS

P- Cleft Palate only
R- Retrognathia (abnormal posterior position of jaw and maxilla)
S- Support to the lingual muscles is lost (Glossoptosis)

The sequence is known to be caused by genetic anomalies at chromosome 2, 11 or 17.


That's all

- Jaskunwar Singh

A Neurology Case Discussion

Hey guys, let's ponder upon the following case.
Before reading this case, just know that this is a case of cerebellar tumor. Now try to localize the tumor in the cerebellum by taking help of the symptoms of this kid. This will help you in the differential diagnosis given later.

A 4 year old complains of headache, drowsiness and occasional diplopia; he is unsteady on his feet with frequent falls. Examination demonstrates truncal ataxia, sometimes accompanied by incoordination of the limbs; variable ophthalmoparesis and papilledema on fundoscopic examination.

Any guesses on what this could be?

Ok so here goes the case discussion:

Medulloblastoma typically presents with a midline cerebellar syndrome, with hydrocephalus and resultant increased intracranial pressure.
Clinically, it can be distinguished from ependymoma involving the fourth ventricle by the early appearance of nausea and vomiting in the latter, due to involvement of area postrema. Cranial nerve palsies may appear with either tumor, and increasing intracranial pressure is typical of both.
The predominance of signs suggesting primary involvement of vermis distinguishes medulloblastoma from cystic or solid astrocytoma of the cerebellum which typically involves a cerebellar hemisphere rather than the vermis. Although rarely there are midline midline astrocytomas.

You are awesome if you were able to get this one right. :)

-VM

Fact of the day: Genesis of the U wave

Hey guys!!

As you know the U wave in the ecg is seldom seen especially in leads V2 and V3 physiologically especially during bradycardia.
And it is seen pathologically in Hypokalemia.

So how is it generated?
If you are thinking due to repolarization of papillary muscles, let me tell you that this hypothesis is now obsolete.

There are three trending theories at present trying to explain it:

1. Delayed repolarization of the subendocardial Purkinje fibres.

2. Prolonged repolarization of the midmyocardium ( M cells)

3. After-potentials resulting from mechanical forces in the ventricular wall.

That's it!

-VM

Fact of the day: Citrobacter causes brain abscesses in neonates

Citrobacter species are Gram-negative enteric bacilli found in the intestinal tract of humans and animals, and are also present in soil and water.

Why does cyanotic heart disease predispose to brain abscess?

Ever wondered why cyanotic heart disease predisposes to brain abscesses?

Step 2 CK: Treatment of Multiple Sclerosis and mnemonics!

Hello!

This post is all about treatment of Multiple Sclerosis.

Creutzfeldt jakob disease mnemonic

Here's one on Creutzfeldt jakob disease :D

Picks disease mnemonic

Hello!

After my infinite struggle, I think I have finally found a way to remember it :D

Percutaneous endoscopic gastrostomy.

Hello awesomites let's know about PEG .

PEG stands for Percutaneous Endoscopic Gastrostomy .We normally use PEG tube .
also known as Feeding tube,Esophagogastroduodenoscopy  tube.=P

In simple language PEG is method of placing a tube into the stomach percutaneously followed by endoscopy .
Tube is passed into a patient's stomach through abdominal wall .
It is preferred route of nutritional support in patients having dysphagia or in unconscious patients.
It offers superior exposure to GI systems.
Most of the PEG tube has mushroom shaped device at the end that holds it in the stomach and prevent it from falling .If it falls do not wait till next day the hole may heal and this may create complications.

Whereas PEG  is also contraindicated in:-
-Distal enteral obstruction.
-Hemodynamic instability.
-Severe ascites.
-Sepsis
-Severe Gastroparesisi.
-Thrombocytopenia.

Scoliosis

Hello awesomites !It's been long time that I haven't written anything due to exam pressure =). Let's start with today's simple topic.

What is scoliosis?

-It's a disorder in which spine has sideways curve like "C" or "S" .It may increases or remain same.Patient usually suffers from breathing problems ,constipation due to tightened organs.
-Factors causing scoliosis are mainly genetic though environmental factors may cause scoliosis.
-Diagnosis is mainly by Plain X-ray.

Treatment?

-Current methods requires surgery to adjust growth rods every 6 months .This may require 8 to 10 procedures in total.

What is MAGEC rods ?

-MAGnetic Expansion Control rods are used as non-invasive adjustments.
Surgeons can lengthen the rods using a Handle-held external magnet.It takes 15 minutes and is performed every 3-6 months .It is also cost effective.Once a surgeon implants the device it's easy to use by remote.
MAGEC is used in children's (normally under 10 age) with severe spine deformity .

Stay awesome:)

~Ojas

Rheumatoid Arthritis deformities : Mnemonic

Hi everyone. This is just a mnemonic post on RA deformities.

So there are 2 important deformities that are definitely seen clinically but are hard to remember.
The Boutonniere and the Swan neck deformities both occur as some defect at 3 joints :
The Proximal Interphalangeal Joint (PIP)  and the Distal Interphalangeal Joint (DIP) and Metacarpophalangeal Joint (MCP).

So Remembering one of them is sufficient as the other one would be the exact inverse.

Remember :

Bout.on.ni.e.re

So Out one Ex .
Which means there's extension at DIP (the outer joint). Now after extension , alternate the next joint with flexion ( so Flexion at PIP ) followed by extension again ( so extension at MCP )

So , Boutonniere is -
DIP - Extension (out one is ex)
PIP - Flexion
MCP - Extension.

And Swan neck would be the opposite :
DIP - Flexion
PIP - Extension
MCP - Flexion

Hope this helped !
Stay awesome.

~ A.P.Burkholderia

Fact of the day: Tugging on heart strings

Hey Awesomites

Since its Valentine's day, here is a love fact you need to know:

Emotional instability and stress associated with constant anxiety (in case you are suffering from I-love-you-penia or broken-heart syndrome) may actually lead to acute emotional trauma to the heart and result in rupture of heart strings, the "chordae tendineae".

The chronic negative effects on heart are associated with Takotsubo cardiomyopathy, aka broken heart syndrome which involves weakening of myocardial muscles and rupture of chordae tendineae leading to right sided heart failure, ventricular arrhythmias and rupture.

So ease your suffering by talking to the love of your life on this special day and confess about your feelings today. <3

Source- Tumblr

Ps- Medicine loves you and cares for you <3
- Jaskunwar Singh

Soap bubble appearance on X ray:Differential diagnosis

Hello everyone!
I always find X rays quite confusing especially when they appear same.
It's a short post about differentiating bone tumors.

Soap bubble appearance on X ray is expansile, eccentric vaguely trabeculated space having thin sharp defined sclerotic margins.
Mostly seen in bone tumors and other bone lesions.
On X ray they all appear same, only way to differentiate them is to know their location and other associated factors.
Commonly seen in
1) Aneurysmal bone cysts-
  Location of ABC is Metaphysis.
It occurs in younger age group i.e less
than 20 years. So the X ray of such
patient will have non fused and 
immature bone.
Preferred sites are long bones of upper and lower limb, especially femur.

2) Giant cell tumor(osteoclastoma) -
Location of GCT is epiphysis
Here the prevalent age group is 20-40, which means an adult sketetal structure.
While the preferred sites are same like ABC.
So if one see epiphyseal lesion with soap bubble appearance in mature bone, it has to be Giant cell tumor.
GCT presents with other classical signs of Egg shell crackling on palpitations.
Giant cells on histology.
Which are NOT the tumor cells. So its one of the example of misnomers. They are meant to misguide you.

Thats it :)
Stay awesome

-Khushboo

Pharmacology: Microsomal metabolism by CYP enzymes in phase 1 mnemonic

Thanks a lot for this video, Shilika!

Pharmacology: When dialysis is not the treatment mnemonic

Video by Shilika!

Fact of the day: 'Experience- taking' from books

Today's fact is relatable for all medicos and books lovers <3

Yes, you can subconsciously take on the attributes of your favourite fictional characters when reading a story- not just the thoughts and beliefs of the character, but the whole state of being itself.

Well, it is more often seen in those who are depressed or who don't have much life experiences of their own.

Also, if the reader is able to relate experiences in the life of character of the story, he might take it to his own life and adopt the mindset and perspective of the character. This may lead to temporary or permanent changes in his real life.

Excessive openness to experiences may lead to schizotypal, narcissistic or paranoid personality disorders among others.


Happy reading :D

- Jaskunwar Singh

Fact of the day: Handedness arises from genes in the spinal cord

Handedness is an asymmetry arising due to left-right differences in the development of nervous system. Evidences suggest that a human embryo of eight weeks is able to move its right arm more than the left arm.

Well, if you know something about neurologic development in-utero, you must know that at eight weeks signals are not transmitted from the brain yet. Instead the signals travel from the spinal cord.

The left side of the cord matures faster than the right cord. This means the genes that control growth and development are activated faster on the left cord than the right one. In the hindbrain, it is the other way around.


That's all
- Jaskunwar Singh

Brucellosis and it's reservoirs mnemonic

Hello!

Here's a mnemonic on Brucellosis and it's reservoirs! :)

Catalase positive organisms mnemonic

Hello!

Here's a mnemonic on Catalase positive organisms :)

Video by Huzaifa Bhopalwala

Enzymes requiring thiamine mnemonic

Can you enlist the enzymes requiring thiamine?

If you can, give yourself a pat on the back and don't read further.

If you can't, give yourself a pat on the back, because you are going to learn how to remember it! :D

Causes of elevated JVP mnemonic

Hey Awesomites

Jugular vein is on a high and stretching out on the RAPs of  "the CREST" .. wohhooo.. :D

R- Right ventricular failure
A- Atrial septal defect (with mitral valve disease)
P- Pericardial compression/ tamponade

C- Circulatory overload
R- Renal failure
E- Excess fluid administration
S- Superior vena cava obstruction
T- Tricuspid stenosis


Hope you enjoy the crest too ;p

- Jaskunwar Singh

Difference between Caput Succedaneum and Cephalhematoma

Hello everyone!
Lemme tell you the difference between Caput Succedaneum and Cephalhematoma today! :)

Bishops score and Manning score mnemonic

Another video by Shilika!

Immunohistochemistry and cytogenetics for leukemias: Part 2

Here's part 2! On Chronic myeloid, chronic lympoid and MDS!

Immunohistochemistry and cytogenetics for Non Hodgkins Lymphoma

Hello!

The Romberg's test does not test cerebellar function

The Romberg's test does not test cerebellar function.

This is a topic that most medical students discuss at some point of time. I have found myself in the midst of similar conversations over my years at medical school.

After much study, I happened to reach an understanding that clarified the purpose of the test and provided a way to understand the results as well.

It would help if you think of the cerebellum as a processor (such as a C.P.U. in a computer).
There are 3 main inputs:


Romberg's test (3 steps):
1. Ask patient to stand with feet together.
2. Ask patient to close both eyes.
3. Maintain the posture for 60 seconds.

The Romberg's test is positive if the patient cannot stand for 60 seconds with feet together and eyes closed.

It is essential to understand that without the processor, the inputs do not matter (as there will be no output and no result).
Thus in Cerebellar ataxia, the patient will be unable to perform any of the above 3 steps and thus the Romberg's test cannot be performed on this patient.

In a situation where the cerebellar function is intact and Romberg's test is performed:
The first input (Vision) is lost when the eyes are closed.
It is now unto the 2 other pathways (Proprioceptive and Vestibular pathways) to provide input to the cerebellum.

Thus the Romberg's test will be positive in cases of:
1. Proprioceptive dysfunction e.g. Sensory peripheral neuropathy & Dorsal column dysfunction
2. Vestibular dysfunction e.g. Vestibular neuritis

This was my attempt to provide a brief summary about this topic and it has been compiled to the best of my understanding. Please feel free to discuss it further, in the comments section below.

Have a great day!

- Vikramjeet Kakade

Immunohistochemistry and cytogenetics for leukemias: Part 1

Hello!

Fact of the day: Most efficient sleep position to clear the brain of waste

Your sleep position at night matters a lot. Not head-up, nor head-down, but sleeping on your side is the most efficient position to clear waste materials from the brain.

This is because the glymphatic system (exchange of CSF with the interstitial fluid to get rid of damaging brain proteins) of our brain works most efficiently in lateral position compared to supine or prone position.

Lateral position and right posture while sleeping is considered advantageous for those suffering from neurologic and psychiatric disorders due to this reason.

That's all

- Jaskunwar Singh

Spermatic Cord contents : Mnemonic

Hello. This is about the things that your thing contains if you're a guy :p

So the spermatic cord is an important content of the inguinal canal in men.

And it contains a host of things.

Remember :

Plenty of Dick Contributes To Good Sex Life

Plenty of = Pampiniform plexus
Dick = Ductus Deferens
Contributes = Cremasteric artery
To = Testicular Artery
Good = Genitofemoral Nerve (Genital br)
Sex = Sympathetic plexus
Life = Lymphatics.

So it's 3 Arteries + 2 nerves + 3 other things.

Hope you like this !
Stay awesome.

Fascia of the thigh : Mnemonic

Hi everyone. This is a short post where I tell you about the thigh fascia.

So fascia of the thigh is super important during surgery , and we are expected to know its layers.
So it's got 2 layers : Camper's and Scarpa's.
Now which is outer and which is inner ?

Remember :

OC IS  good.

So OC = Outer Camper
       IS  = Inner Scarpa

Hope you liked this!
Stay awesome.

Schistosoma mansoni and Schistosoma haematobium mnemonic

Here is the video :)

East African Sleeping Sickness and West African Sleeping Sickness mnemonic

Here is the video :)

Naked RNA viruses mnemonic

Here is the video!

Side effects of anti-glaucoma drugs mnemonic

Here's the video!