Microbiology High Yield

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B19 virus: at-risk groups
B19 affects 3 B's:
Babies (5th disease, infectiousum erythematosa)
Black Bleeders (sickle cell anemics - anaplastic anemic crisis)
Bearing Babies [pregnant women] (hydrops fetalis)
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IgA protease-producing bacteria
"Nice Strip of Ham":
Neisseria
Streptococcus pneumonia
Haemophilus influenza
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Hemophilius: culture requirements
Read Hemophilus as "HemoFive":
· Needs Heme with Factors Five and Ten.
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DNA viruses: morphology rule of thumb
DNA:
Double-stranded
Nuclear replication
'Anhedral symmetry
· Rule breakers: pox (cytoplasmic), parvo (single-stranded).
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Streptococcus pyogenes: virulence factors
SMASHED:
Streptolysins
M protein
Anti-C5a peptidase
Streptokinase
Hyaluronidase
Exotoxin
DNAses

Food poisoning: bugs inducing
"Eating Contaminated Stuff Causes Very Big Smelly Vomit":
E. coli O157-H7 [undercooked meat, esp. hamburgers]
Clostridium botulinum [canned foods]
Salmonella [poultry, meat, eggs]
Vibrio parahaemolyticus [seafood]
Bacillus cereus [reheated rice]
Staphylococcus aureus [meats, mayo, custard]
Clostridium perfringens [reheated meat]
Vibrio vulnificus [seafood]
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Neonatal Tetanus

Tetanus Neonatorum : Generalized paucity of movement associated with stiffness and rigidity or spasms (Opisthotonos).Trismus (lockjaw) is the reason of feeding difficulty. Baby is on Oxygen due to affection of respiratory muscles.
2. Management:
1. Ensure patent airway
2. Respiratory support as required
3.Ensure nutrition and hydration
4. Human tetanus immunoglobulin (TIG) as soon as possible to neutralize the toxin
A single IM of 500 U of TIG is sufficient to neutralize systemic tetanus toxin, but total doses as high as 3,000–6,000 U are also recommended. Tetanus toxin cannot be neutralized by TIG after it has begun its axonal ascent to the spinal cord.
5. Diazepam for both muscle relaxation and seizure control. Other muscle relaxants can be used like Baclofen as well.
6. Penicillin G to eradicate Clostridium tetani. 100,000 U/kg/day divided every 4–6 hr IV for 10–14 days
7. Excision of the umbilical stump is no longer recommended but, good cleaning

Blood indices

Various indices to differentiate between IDA n BETA THALASSEMIA:
1. MENTZER INDEX 👉 IDA >13, BT< 13

2.SHINE AND LAL INDEX 👉 IDA>1530, BT< 1530

3.ENGLAND AND FRASER INDEX👉 IDA>0, BT<0

4.SHRIVASTAVA INDEX👉 IDA>3.8, BT<3.8

5. GREEN AND KING INDEX👉 IDA>65, BT<65

6.RED CELL DISTRIBUTION WIDTH INDEX👉 IDA> 220, BT< 220

   

Doses

Dose of metronidazole for extra intestinal amebiasis?
800 mg tds × 7-10 d

Dose of metronidazole for intestinal amebiasis?
400 mg tds× 5-7 d

Drug that inhibit pyruvate ferredoxin reductase??
Ntazoxanide

Dose of mebendazole  for hookworm infestation ??
200mg/d ×3 days

Dose of albendazole  for hookworm infestation ??
400mg single dose

Standard dose of doxycycline ??
100mg BD

Dose of vanco for Rx of MRSA?
500mg QID

Adverse effects of Glucocorticoids

Adverse effects of Glucocorticoids

GLUCOCORTICOIDS

G glaucoma
L lunacy(psychotic episodes)
U peptic Ulceration
C cushings habitus
O osteoporosis
C cataracts(post. subcapsular in
children)
O opportunistic infections
R Retention of Na,H2O
(mineralocort.)
T telangectasia
I insulin resistance->
hyperglycaemia
C causes muscle weakness on
withdrawal
O grOwth reatrdation
I by GH inhibition
D delayed wound healing
S supresses HPA axis

CVA

#CVA (cerebrovascular accident) synopsis

CVA most common cause
Ischemia >emboli> thrombus> heamorrhage

In Haemorrhage -
Intracerebral> SAH > SDH ~ EDH

Among intracerbral -
Mc cause - HTN
Site - putamen>basal ganglia>thalamus> cerebellum> pons

Among SAH
Cause -
Headtrauma > saccular anneursym > berrys aneurysm > circle of wills

Mc site - anterior cerebral artery circulation

Porphyrias

#HYI PORPHYRIA
Most Common Type: Porphyria Cutanea Tarda with basic enzyme deficiency: uroporphyrinogen decarboxylase and Maximum Phototoxicity.

Psychiatric manifestation and Phototoxicity NOT seen: Acute Intermittent Porphyria

Erythropoietic protoporphyria: Ferrochelatase deficiency

Congenital Erythropoietic porphyria: (Only porphyria with A.R)Uroporphyrinogen III synthase

Pseudoporphyria: A [bleep] photosensitivity that clinically and histologically mimics PCT.chronic renal failure treated with hemodialysis,exposure to ultraviolet A (UV-A), Drugs.

Variegate porphyria: protoporphyrinogen oxidase def,cutaneous photosensitivity, systemic symptoms arising from neurologic dysfunction, or both.

Acute Intermittent Porphyria, Varigate Porphyria and Congenital erythropoietic porphyria produce increase in urine prophobilinogen.