USMLE Step 1 Micro
Staph Aureus
Gram "+" in clusters
β-Hemolytic
Catalase "+"
Coagulase "+"
Risk Factors
-IV Drug use
-Intravascular Catheters (For Nocosomial infections)
Virulence Factors
-Exfoliative Toxin A (Protease which targets Desmoglein in Bullous Impetigo)
-Preformed Enterotoxin
Azoles
MOA
-Inhibition of Cytochrome P450-dependent Demethylation reaction which synthesizes
Ergosterol from Lanosterol
Used for Oral Tx of Vulva Candidiasis
Ascaris Lumbricoides
Dx
-Large white worms in stool
Transmission
-Egg-contaminated food or H2O
**Hematogenous spread to the Liver**
Haemophillus Influenzae Vaccine
Neisseriaa Meningitidis Vaccine
Streptococcus Penumoniae Vaccine
,Conjugated Capsular Polysaccharide vaccine
Oral Typhoid Vaccine
Live Attenuated Bacterial vaccine
Clostridium Tetani Vaccine
Corynebacterium Diptherie Vaccine
Bortadella Pertussis Vaccine
Toxoid-based Vaccines
Haemophilus Influenzae
Dx
-Inflammation + Edema of Supraglottic tissue
Bortadella Pertusis
Dx
-Clearance/Loss of Ciliated Respiratory Epithelial Cells
Influenza Virus
Retrograde Virus
Viruses which replicate inside the Cell Nucleus
Staph Aureus
Reservoir
-Anterior Nare colonization
Sx
-Osteoarthritis
-Endocarditis (Most commonly affects the Tricuspid Valve)
-Skin + Tissue (I.e. Hepatic) Abscess
-Scalded Skin Syndrome
-Hepatic Fluid-filled Cavity/Abscesses (D/t Hematogenous spread)
-Right-sided Endocarditis
-Toxic Shock Syndrome
,-Bullous Impetigo (Honey-crusted blistering skin rash)
**Immune response is mediated by Neutrophils + B-cells**
Mycoses Fungoides
Cutaneous T-Cell Lymphoma
Commonly affects the Axilla + Buttocks
Sx
-Erythematous wrinkled scaly skin patches
Complications
-Thickening of skin patches
-Progression of skin patches into tumors
Hypochlorite
Important compound which is involved in the efficient killing of bacteria as it is a component of
the Respiratory Burst → Rapid Bacterial killing
Bacteroides Fragilis
Gram "-" Rod
Does NOT grow well on McConkey Agar
It causes infections when displaced from the Colon (I.e. Appendix rupture)
Higher chance than E. Coli to be infiltrated in Appendix Rupture since its a commensal of the
GIT
Death Receptor Extrinsic Pathway
Risk Factors
-Viral Hepatitis
Mitochondrial Intrinsic Pathway
Risk Factors
-Radiotherapy
-Oxidative damage
-Ischemia
, -Toxin exposure
Taenia Solium
Pork Tapeworm
Transmission
-Fecal Oral
Sx
-Adult-onset seizures
-Headaches
-Vomiting
MRI
-Cysts within the Brain
Tx
-Praziquantel
Neurocysticercosis
Etiology
-Taenia Solium
Dx
-Calcified Nodules + Cysts in the Brain
-Seizures
Staph Epidermidis
Dx
-Gram "+" Cocci
-Catalase "+"
-Coagulase "-"
-Novobiocin Sensitive
**Urease "+"
Staph Aureus
Gram "+" in clusters
β-Hemolytic
Catalase "+"
Coagulase "+"
Risk Factors
-IV Drug use
-Intravascular Catheters (For Nocosomial infections)
Virulence Factors
-Exfoliative Toxin A (Protease which targets Desmoglein in Bullous Impetigo)
-Preformed Enterotoxin
Azoles
MOA
-Inhibition of Cytochrome P450-dependent Demethylation reaction which synthesizes
Ergosterol from Lanosterol
Used for Oral Tx of Vulva Candidiasis
Ascaris Lumbricoides
Dx
-Large white worms in stool
Transmission
-Egg-contaminated food or H2O
**Hematogenous spread to the Liver**
Haemophillus Influenzae Vaccine
Neisseriaa Meningitidis Vaccine
Streptococcus Penumoniae Vaccine
,Conjugated Capsular Polysaccharide vaccine
Oral Typhoid Vaccine
Live Attenuated Bacterial vaccine
Clostridium Tetani Vaccine
Corynebacterium Diptherie Vaccine
Bortadella Pertussis Vaccine
Toxoid-based Vaccines
Haemophilus Influenzae
Dx
-Inflammation + Edema of Supraglottic tissue
Bortadella Pertusis
Dx
-Clearance/Loss of Ciliated Respiratory Epithelial Cells
Influenza Virus
Retrograde Virus
Viruses which replicate inside the Cell Nucleus
Staph Aureus
Reservoir
-Anterior Nare colonization
Sx
-Osteoarthritis
-Endocarditis (Most commonly affects the Tricuspid Valve)
-Skin + Tissue (I.e. Hepatic) Abscess
-Scalded Skin Syndrome
-Hepatic Fluid-filled Cavity/Abscesses (D/t Hematogenous spread)
-Right-sided Endocarditis
-Toxic Shock Syndrome
,-Bullous Impetigo (Honey-crusted blistering skin rash)
**Immune response is mediated by Neutrophils + B-cells**
Mycoses Fungoides
Cutaneous T-Cell Lymphoma
Commonly affects the Axilla + Buttocks
Sx
-Erythematous wrinkled scaly skin patches
Complications
-Thickening of skin patches
-Progression of skin patches into tumors
Hypochlorite
Important compound which is involved in the efficient killing of bacteria as it is a component of
the Respiratory Burst → Rapid Bacterial killing
Bacteroides Fragilis
Gram "-" Rod
Does NOT grow well on McConkey Agar
It causes infections when displaced from the Colon (I.e. Appendix rupture)
Higher chance than E. Coli to be infiltrated in Appendix Rupture since its a commensal of the
GIT
Death Receptor Extrinsic Pathway
Risk Factors
-Viral Hepatitis
Mitochondrial Intrinsic Pathway
Risk Factors
-Radiotherapy
-Oxidative damage
-Ischemia
, -Toxin exposure
Taenia Solium
Pork Tapeworm
Transmission
-Fecal Oral
Sx
-Adult-onset seizures
-Headaches
-Vomiting
MRI
-Cysts within the Brain
Tx
-Praziquantel
Neurocysticercosis
Etiology
-Taenia Solium
Dx
-Calcified Nodules + Cysts in the Brain
-Seizures
Staph Epidermidis
Dx
-Gram "+" Cocci
-Catalase "+"
-Coagulase "-"
-Novobiocin Sensitive
**Urease "+"
