MMR vaccine answer in micro for 5 marks
| Component | Strain Used |
|---|---|
| Measles | Schwartz or Moraten substrains of Edmonton B strain |
| Mumps | Jeryl Lynn strain |
| Rubella | RA 27/3 strain |
Sources: Medical Microbiology 9e (Murray et al.) - Box 48.4; Sherris & Ryan's Medical Microbiology 8e; Goldman-Cecil Medicine
Create a summary PDF on MMR vaccine for exam prep
ls /home/daytona/workspace/ 2>/dev/null || echo "workspace empty or missing"
mkdir -p /home/daytona/workspace/mmr-vaccine && echo "created"
~/mmr-vaccine/generate_pdf.py
from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import mm, cm
from reportlab.platypus import (
SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
HRFlowable, KeepTogether
)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.platypus import PageBreak
OUTPUT = "/home/daytona/workspace/mmr-vaccine/MMR_Vaccine_Exam_Summary.pdf"
# ── colours ──────────────────────────────────────────────────────────────────
C_DARK = colors.HexColor("#1A237E") # deep indigo – headings
C_MED = colors.HexColor("#283593") # mid indigo
C_ACCENT = colors.HexColor("#E53935") # red – highlights / danger
C_GREEN = colors.HexColor("#2E7D32") # green – efficacy / tips
C_AMBER = colors.HexColor("#F57F17") # amber – caution
C_TEAL = colors.HexColor("#00695C") # teal – key points
C_BG = colors.HexColor("#E8EAF6") # lavender bg – section bands
C_BG2 = colors.HexColor("#E8F5E9") # green-tint bg
C_BG3 = colors.HexColor("#FFF3E0") # orange-tint bg
C_BORDER = colors.HexColor("#3949AB")
C_WHITE = colors.white
C_LGRAY = colors.HexColor("#F5F5F5")
C_GRAY = colors.HexColor("#757575")
# ── styles ────────────────────────────────────────────────────────────────────
styles = getSampleStyleSheet()
def S(name, **kw):
return ParagraphStyle(name, **kw)
style_title = S("Title2",
fontSize=26, fontName="Helvetica-Bold",
textColor=C_WHITE, alignment=TA_CENTER, spaceAfter=4)
style_subtitle = S("Subtitle2",
fontSize=13, fontName="Helvetica",
textColor=C_WHITE, alignment=TA_CENTER, spaceAfter=2)
style_tag = S("Tag",
fontSize=10, fontName="Helvetica-Oblique",
textColor=colors.HexColor("#C5CAE9"), alignment=TA_CENTER)
style_h2 = S("H2",
fontSize=13, fontName="Helvetica-Bold",
textColor=C_WHITE, spaceBefore=6, spaceAfter=4, leftIndent=6)
style_body = S("Body2",
fontSize=10, fontName="Helvetica",
textColor=colors.HexColor("#212121"),
leading=15, spaceAfter=3, leftIndent=4)
style_bullet = S("Bullet2",
fontSize=10, fontName="Helvetica",
textColor=colors.HexColor("#212121"),
leading=15, spaceAfter=2,
leftIndent=16, firstLineIndent=-10)
style_bold_bullet = S("BoldBullet",
fontSize=10, fontName="Helvetica-Bold",
textColor=C_DARK,
leading=15, spaceAfter=2,
leftIndent=16, firstLineIndent=-10)
style_note = S("Note",
fontSize=9.5, fontName="Helvetica-Oblique",
textColor=C_GRAY, leading=13, spaceAfter=2, leftIndent=4)
style_mnemonic = S("Mnemonic",
fontSize=11, fontName="Helvetica-Bold",
textColor=C_TEAL, alignment=TA_CENTER, spaceBefore=4, spaceAfter=4)
style_footer = S("Footer",
fontSize=8, fontName="Helvetica",
textColor=C_GRAY, alignment=TA_CENTER)
style_table_hdr = S("TblHdr",
fontSize=10, fontName="Helvetica-Bold",
textColor=C_WHITE, alignment=TA_CENTER)
style_table_cell = S("TblCell",
fontSize=9.5, fontName="Helvetica",
textColor=colors.HexColor("#212121"), alignment=TA_LEFT, leading=13)
style_table_cell_c = S("TblCellC",
fontSize=9.5, fontName="Helvetica",
textColor=colors.HexColor("#212121"), alignment=TA_CENTER, leading=13)
style_warn = S("Warn",
fontSize=10, fontName="Helvetica-Bold",
textColor=C_ACCENT, spaceBefore=2, spaceAfter=2, leftIndent=4)
# ── helpers ───────────────────────────────────────────────────────────────────
def section_header(title, bg=C_DARK):
"""A full-width coloured band with white title."""
data = [[Paragraph(title, style_h2)]]
t = Table(data, colWidths=[170*mm])
t.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,-1), bg),
("ROUNDEDCORNERS", [4]),
("TOPPADDING", (0,0), (-1,-1), 5),
("BOTTOMPADDING", (0,0), (-1,-1), 5),
("LEFTPADDING", (0,0), (-1,-1), 8),
]))
return t
def bullet(text, bold=False):
st = style_bold_bullet if bold else style_bullet
return Paragraph(f"• {text}", st)
def spacer(h=4):
return Spacer(1, h*mm)
def hr(color=C_BORDER, thickness=0.5):
return HRFlowable(width="100%", thickness=thickness, color=color, spaceAfter=3)
# ── document ─────────────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
OUTPUT,
pagesize=A4,
topMargin=15*mm, bottomMargin=18*mm,
leftMargin=20*mm, rightMargin=20*mm,
title="MMR Vaccine – Exam Summary",
author="Medical Microbiology"
)
story = []
# ════════════════════════════════════════════════════════════════════
# COVER BLOCK
# ════════════════════════════════════════════════════════════════════
cover_data = [[
Paragraph("MMR VACCINE", style_title),
Paragraph("Measles · Mumps · Rubella", style_subtitle),
Paragraph("Microbiology Exam Prep | 5-Mark Answer Guide", style_tag),
]]
cover = Table([[
Paragraph("MMR VACCINE", style_title),
]], colWidths=[170*mm])
cover.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,-1), C_DARK),
("ALIGN", (0,0), (-1,-1), "CENTER"),
("TOPPADDING", (0,0), (-1,-1), 14),
("BOTTOMPADDING", (0,0), (-1,-1), 4),
("LEFTPADDING", (0,0), (-1,-1), 10),
]))
sub = Table([[
Paragraph("Measles · Mumps · Rubella", style_subtitle),
]], colWidths=[170*mm])
sub.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,-1), C_DARK),
("ALIGN", (0,0), (-1,-1), "CENTER"),
("TOPPADDING", (0,0), (-1,-1), 2),
("BOTTOMPADDING", (0,0), (-1,-1), 4),
]))
tag = Table([[
Paragraph("Microbiology Exam Prep | 5-Mark Answer Guide", style_tag),
]], colWidths=[170*mm])
tag.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,-1), C_MED),
("ALIGN", (0,0), (-1,-1), "CENTER"),
("TOPPADDING", (0,0), (-1,-1), 4),
("BOTTOMPADDING", (0,0), (-1,-1), 8),
]))
story += [cover, sub, tag, spacer(5)]
# ════════════════════════════════════════════════════════════════════
# 1. INTRODUCTION
# ════════════════════════════════════════════════════════════════════
story.append(section_header("1. Introduction"))
story.append(spacer(2))
story.append(Paragraph(
"The MMR vaccine is a <b>combined live attenuated viral vaccine</b> that confers "
"simultaneous protection against three infectious diseases: "
"<b>Measles</b> (Rubeola), <b>Mumps</b>, and <b>Rubella</b> (German Measles). "
"It is one of the most successful public-health interventions in modern medicine.",
style_body))
story.append(spacer(3))
# ════════════════════════════════════════════════════════════════════
# 2. COMPOSITION
# ════════════════════════════════════════════════════════════════════
story.append(section_header("2. Composition"))
story.append(spacer(2))
comp_data = [
[Paragraph("Component", style_table_hdr),
Paragraph("Strain", style_table_hdr),
Paragraph("Type", style_table_hdr)],
[Paragraph("Measles", style_table_cell_c),
Paragraph("Schwartz or Moraten substrains of Edmonton B", style_table_cell),
Paragraph("Live attenuated", style_table_cell_c)],
[Paragraph("Mumps", style_table_cell_c),
Paragraph("Jeryl Lynn strain", style_table_cell),
Paragraph("Live attenuated", style_table_cell_c)],
[Paragraph("Rubella", style_table_cell_c),
Paragraph("RA 27/3 strain", style_table_cell),
Paragraph("Live attenuated", style_table_cell_c)],
]
comp_table = Table(comp_data, colWidths=[38*mm, 90*mm, 42*mm])
comp_table.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,0), C_MED),
("BACKGROUND", (0,1), (-1,1), C_LGRAY),
("BACKGROUND", (0,2), (-1,2), C_WHITE),
("BACKGROUND", (0,3), (-1,3), C_LGRAY),
("GRID", (0,0), (-1,-1), 0.4, colors.HexColor("#9FA8DA")),
("ROWBACKGROUNDS",(0,0), (-1,-1), [C_BG, C_WHITE]),
("BACKGROUND", (0,0), (-1,0), C_MED),
("TOPPADDING", (0,0), (-1,-1), 5),
("BOTTOMPADDING", (0,0), (-1,-1), 5),
("LEFTPADDING", (0,0), (-1,-1), 6),
("ALIGN", (0,0), (0,-1), "CENTER"),
("ALIGN", (2,0), (2,-1), "CENTER"),
("VALIGN", (0,0), (-1,-1), "MIDDLE"),
]))
story.append(comp_table)
story.append(spacer(2))
story.append(Paragraph(
"<b>Other components:</b> Neomycin (antibiotic), gelatin (stabiliser), sorbitol.",
style_note))
story.append(Paragraph(
"<b>MMRV:</b> A quadrivalent form also containing live attenuated Varicella (chickenpox) virus.",
style_note))
story.append(spacer(3))
# ════════════════════════════════════════════════════════════════════
# 3. VACCINATION SCHEDULE
# ════════════════════════════════════════════════════════════════════
story.append(section_header("3. Vaccination Schedule"))
story.append(spacer(2))
sched_data = [
[Paragraph("Dose", style_table_hdr),
Paragraph("Age", style_table_hdr),
Paragraph("Route & Dose", style_table_hdr),
Paragraph("Notes", style_table_hdr)],
[Paragraph("1st", style_table_cell_c),
Paragraph("12 – 15 months", style_table_cell_c),
Paragraph("0.5 mL SC", style_table_cell_c),
Paragraph("After maternal Ab cleared", style_table_cell)],
[Paragraph("2nd", style_table_cell_c),
Paragraph("4 – 6 years\n(pre-school)", style_table_cell_c),
Paragraph("0.5 mL SC", style_table_cell_c),
Paragraph("Boosters herd immunity; mandatory in many states", style_table_cell)],
[Paragraph("Catch-up", style_table_cell_c),
Paragraph("≤ 11 – 12 years", style_table_cell_c),
Paragraph("0.5 mL SC", style_table_cell_c),
Paragraph("For those who missed 2nd dose", style_table_cell)],
]
sched_table = Table(sched_data, colWidths=[20*mm, 38*mm, 32*mm, 80*mm])
sched_table.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,0), C_MED),
("ROWBACKGROUNDS",(0,1), (-1,-1), [C_LGRAY, C_WHITE]),
("GRID", (0,0), (-1,-1), 0.4, colors.HexColor("#9FA8DA")),
("TOPPADDING", (0,0), (-1,-1), 5),
("BOTTOMPADDING", (0,0), (-1,-1), 5),
("LEFTPADDING", (0,0), (-1,-1), 5),
("ALIGN", (0,0), (2,-1), "CENTER"),
("VALIGN", (0,0), (-1,-1), "MIDDLE"),
]))
story.append(sched_table)
story.append(spacer(3))
# ════════════════════════════════════════════════════════════════════
# 4. EFFICACY
# ════════════════════════════════════════════════════════════════════
story.append(section_header("4. Efficacy", bg=C_GREEN))
story.append(spacer(2))
eff_data = [
[Paragraph("Disease", style_table_hdr),
Paragraph("1 Dose", style_table_hdr),
Paragraph("2 Doses", style_table_hdr)],
[Paragraph("Measles", style_table_cell_c),
Paragraph("~95% lifelong seroconversion", style_table_cell_c),
Paragraph("~99%", style_table_cell_c)],
[Paragraph("Mumps", style_table_cell_c),
Paragraph("~80%", style_table_cell_c),
Paragraph("~90% ← <b>2 doses essential</b>", style_table_cell_c)],
[Paragraph("Rubella", style_table_cell_c),
Paragraph("~95% lifelong", style_table_cell_c),
Paragraph("Added safeguard vs primary failure", style_table_cell_c)],
]
eff_table = Table(eff_data, colWidths=[38*mm, 66*mm, 66*mm])
eff_table.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,0), C_GREEN),
("ROWBACKGROUNDS",(0,1), (-1,-1), [C_BG2, C_WHITE]),
("GRID", (0,0), (-1,-1), 0.4, colors.HexColor("#A5D6A7")),
("TOPPADDING", (0,0), (-1,-1), 5),
("BOTTOMPADDING", (0,0), (-1,-1), 5),
("LEFTPADDING", (0,0), (-1,-1), 6),
("ALIGN", (0,0), (-1,-1), "CENTER"),
("VALIGN", (0,0), (-1,-1), "MIDDLE"),
]))
story.append(eff_table)
story.append(spacer(2))
story.append(bullet(
"<b>Herd immunity threshold for measles:</b> >93% population coverage required.",
bold=False))
story.append(bullet(
"Measles eradication candidate (single serotype, human-only reservoir) – but hindered by cold-chain requirements.",
bold=False))
story.append(spacer(3))
# ════════════════════════════════════════════════════════════════════
# 5. CONTRAINDICATIONS
# ════════════════════════════════════════════════════════════════════
story.append(section_header("5. Contraindications", bg=C_ACCENT))
story.append(spacer(2))
ci_items = [
("<b>Pregnancy</b>", "Live vaccine – teratogenic risk. Avoid pregnancy for <b>≥1 month</b> post-vaccination."),
("<b>Immunocompromised</b>", "HIV, malignancy, high-dose steroids, immunosuppressive therapy."),
("<b>Allergy to Gelatin or Neomycin</b>", "Both are components of the vaccine preparation."),
("<b>Active febrile illness</b>", "Defer until recovery."),
("<b>Recent immunoglobulin / blood products</b>", "Wait 3–11 months before giving MMR (Ab interference)."),
]
ci_data = [[Paragraph(a, style_table_cell), Paragraph(b, style_table_cell)]
for a, b in ci_items]
ci_table = Table(ci_data, colWidths=[55*mm, 115*mm])
ci_table.setStyle(TableStyle([
("ROWBACKGROUNDS", (0,0), (-1,-1), [colors.HexColor("#FFEBEE"), C_WHITE]),
("GRID", (0,0), (-1,-1), 0.4, colors.HexColor("#EF9A9A")),
("TOPPADDING", (0,0), (-1,-1), 5),
("BOTTOMPADDING", (0,0), (-1,-1), 5),
("LEFTPADDING", (0,0), (-1,-1), 6),
("VALIGN", (0,0), (-1,-1), "MIDDLE"),
]))
story.append(ci_table)
story.append(spacer(2))
story.append(Paragraph(
"⚠ Immunocompromised contacts exposed to measles → give <b>Immunoglobulin within 6 days</b>.",
style_warn))
story.append(spacer(3))
# ════════════════════════════════════════════════════════════════════
# 6. ADVERSE EFFECTS
# ════════════════════════════════════════════════════════════════════
story.append(section_header("6. Adverse Effects", bg=C_AMBER))
story.append(spacer(2))
ae_data = [
[Paragraph("Effect", style_table_hdr),
Paragraph("Component", style_table_hdr),
Paragraph("Frequency", style_table_hdr)],
[Paragraph("Mild fever, malaise", style_table_cell),
Paragraph("Measles", style_table_cell_c),
Paragraph("Common", style_table_cell_c)],
[Paragraph("Rash (transient)", style_table_cell),
Paragraph("Measles / Rubella", style_table_cell_c),
Paragraph("Common", style_table_cell_c)],
[Paragraph("Lymphadenopathy", style_table_cell),
Paragraph("Rubella", style_table_cell_c),
Paragraph("Common", style_table_cell_c)],
[Paragraph("Parotid swelling", style_table_cell),
Paragraph("Mumps", style_table_cell_c),
Paragraph("Uncommon", style_table_cell_c)],
[Paragraph("Febrile seizures", style_table_cell),
Paragraph("All", style_table_cell_c),
Paragraph("Rare", style_table_cell_c)],
[Paragraph("Thrombocytopenic purpura", style_table_cell),
Paragraph("Measles", style_table_cell_c),
Paragraph("Very rare", style_table_cell_c)],
[Paragraph("Arthralgia / Arthritis", style_table_cell),
Paragraph("Rubella", style_table_cell_c),
Paragraph("Adults only", style_table_cell_c)],
]
ae_table = Table(ae_data, colWidths=[80*mm, 50*mm, 40*mm])
ae_table.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,0), C_AMBER),
("ROWBACKGROUNDS",(0,1), (-1,-1), [C_BG3, C_WHITE]),
("GRID", (0,0), (-1,-1), 0.4, colors.HexColor("#FFE082")),
("TOPPADDING", (0,0), (-1,-1), 5),
("BOTTOMPADDING", (0,0), (-1,-1), 5),
("LEFTPADDING", (0,0), (-1,-1), 6),
("VALIGN", (0,0), (-1,-1), "MIDDLE"),
("ALIGN", (1,0), (2,-1), "CENTER"),
]))
story.append(ae_table)
story.append(spacer(2))
story.append(Paragraph(
"✓ Alleged MMR-autism link is <b>thoroughly disproven</b> by large population studies. "
"The original 1998 Wakefield paper was retracted.",
style_note))
story.append(spacer(3))
# ════════════════════════════════════════════════════════════════════
# 7. POST-EXPOSURE & SPECIAL SITUATIONS
# ════════════════════════════════════════════════════════════════════
story.append(section_header("7. Post-Exposure Prophylaxis & Special Situations", bg=C_TEAL))
story.append(spacer(2))
story.append(bullet(
"<b>MMR post-exposure:</b> Effective only if given <b>within 72 hours</b> of exposure to measles."))
story.append(bullet(
"<b>Immunoglobulin (IG):</b> For immunocompromised / infants <6 months – give within <b>6 days</b> of measles exposure."))
story.append(bullet(
"<b>Mumps post-exposure:</b> MMR does NOT provide effective post-exposure prophylaxis for mumps."))
story.append(bullet(
"<b>Rubella in pregnancy:</b> Exposed non-immune pregnant women – give IG; advise about fetal risk (Congenital Rubella Syndrome)."))
story.append(bullet(
"<b>HIV patients:</b> MMR can be given to <i>asymptomatic</i> HIV+ children with adequate CD4 counts."))
story.append(bullet(
"<b>Vitamin A:</b> High-dose Vitamin A reduces measles mortality (WHO recommendation)."))
story.append(spacer(3))
# ════════════════════════════════════════════════════════════════════
# 8. MNEMONIC & EXAM HIGH-YIELDS
# ════════════════════════════════════════════════════════════════════
story.append(section_header("8. Mnemonic & Exam High-Yields", bg=C_TEAL))
story.append(spacer(2))
# Mnemonic box
mn_data = [[Paragraph(
"Mnemonic – Strains: \"<b>S</b>weet <b>J</b>elly <b>R</b>oll\"<br/>"
"S = Schwartz/Moraten (Measles) | J = Jeryl Lynn (Mumps) | R = RA 27/3 (Rubella)",
style_mnemonic)]]
mn_table = Table(mn_data, colWidths=[170*mm])
mn_table.setStyle(TableStyle([
("BACKGROUND", (0,0), (-1,-1), colors.HexColor("#E0F2F1")),
("GRID", (0,0), (-1,-1), 1.0, C_TEAL),
("TOPPADDING", (0,0), (-1,-1), 8),
("BOTTOMPADDING", (0,0), (-1,-1), 8),
("LEFTPADDING", (0,0), (-1,-1), 10),
("ROUNDEDCORNERS",[4]),
]))
story.append(mn_table)
story.append(spacer(3))
hy_items = [
("Type of vaccine", "Live attenuated – NOT killed / inactivated"),
("Route", "Subcutaneous (SC), 0.5 mL"),
("1st dose age", "12 – 15 months (after maternal Ab wane)"),
("2nd dose age", "4 – 6 years"),
("Measles 1-dose efficacy", "~95% lifelong seroconversion"),
("Mumps efficacy", "~80% (1 dose); ~90% (2 doses) – 2 doses essential"),
("Herd immunity threshold", ">93% for measles"),
("Key CI", "Pregnancy, immunocompromised, gelatin/neomycin allergy"),
("Post-exposure measles", "MMR within 72 h OR IG within 6 days"),
("Autism link", "Disproven – Wakefield paper retracted"),
("Measles eradication", "Possible (single serotype) – hindered by cold-chain"),
("WHO additional measure", "High-dose Vitamin A reduces measles mortality"),
]
hy_data = [[Paragraph("<b>" + k + "</b>", style_table_cell),
Paragraph(v, style_table_cell)] for k, v in hy_items]
hy_table = Table(hy_data, colWidths=[70*mm, 100*mm])
hy_table.setStyle(TableStyle([
("ROWBACKGROUNDS", (0,0), (-1,-1), [C_BG, C_WHITE]),
("GRID", (0,0), (-1,-1), 0.3, colors.HexColor("#9FA8DA")),
("TOPPADDING", (0,0), (-1,-1), 5),
("BOTTOMPADDING", (0,0), (-1,-1), 5),
("LEFTPADDING", (0,0), (-1,-1), 6),
("VALIGN", (0,0), (-1,-1), "MIDDLE"),
]))
story.append(hy_table)
story.append(spacer(4))
# ════════════════════════════════════════════════════════════════════
# FOOTER
# ════════════════════════════════════════════════════════════════════
story.append(hr(color=C_BORDER, thickness=0.8))
story.append(Paragraph(
"Sources: Medical Microbiology 9e (Murray et al.) – Box 48.4 | Sherris & Ryan's Medical Microbiology 8e | "
"Goldman-Cecil Medicine | Red Book 2021 (AAP) | Harrison's Principles 22E",
style_footer))
# ── BUILD ────────────────────────────────────────────────────────────────────
doc.build(story)
print(f"PDF saved to {OUTPUT}")
cd /home/daytona/workspace/mmr-vaccine && python generate_pdf.py 2>&1
MMR Vaccine Exam Summary
PDF Document · PDF
| Section | Content |
|---|---|
| 1. Introduction | Definition - combined live attenuated vaccine |
| 2. Composition | Strain table: Schwartz/Moraten, Jeryl Lynn, RA 27/3 |
| 3. Schedule | 1st dose (12-15 months), 2nd dose (4-6 years), catch-up |
| 4. Efficacy | Per-disease seroconversion rates with color-coded table |
| 5. Contraindications | Pregnancy, immunocompromised, gelatin/neomycin allergy |
| 6. Adverse Effects | Per-component breakdown with frequency |
| 7. Post-Exposure & Special Situations | IG timing, HIV, Vitamin A |
| 8. Mnemonics & High-Yields | "Sweet Jelly Roll" mnemonic + 12-row quick-reference table |
Define Toxic Shock Syndrome. Describe its Pathogenesis. Describe the Clinical Spectrum & Lab Diagnosis of the Causative Organism. Add a Note on MRSA (Staphylococcus aureus) (
TSST-1 (Superantigen)
↓
Binds simultaneously to:
- Class II MHC molecules on macrophages/APCs
- Vβ region of T-cell receptor (TCR)
↓
Massive, non-specific T-cell activation (up to 20-30% of all T cells)
↓
Cytokine Storm:
- Macrophages → IL-1β, TNF-α
- T cells → IL-2, IFN-γ, TNF-β
↓
IL-1β → FEVER
TNF-α, TNF-β → HYPOTENSION, SHOCK, endothelial damage
IFN-γ → multi-organ injury
90% of adults have antibodies to TSST-1 - but >50% of TSS patients fail to develop protective antibodies after recovery
| Feature | Description |
|---|---|
| Fever | Temperature ≥38.9°C (102°F) |
| Hypotension | Systolic BP ≤90 mmHg in adults; orthostatic drop ≥15 mmHg |
| Rash | Diffuse macular erythroderma (sunburn-like) |
| Desquamation | 1-2 weeks after onset, especially palms and soles |
| Multi-organ involvement | ≥3 of the following systems |
| System | Manifestation |
|---|---|
| GI | Vomiting, watery diarrhea at onset |
| Musculoskeletal | Myalgia, elevated CPK (≥2x normal) |
| Renal | Oliguria, azotemia, pyuria without infection |
| Hepatic | Elevated bilirubin, AST/ALT (≥2x normal) |
| Hematologic | Thrombocytopenia (<100,000/mm³), DIC |
| CNS | Disorientation, altered consciousness without focal signs |
| Pulmonary | Bilateral infiltrates ("shock lung"/ARDS) |
| Cardiovascular | Hypotension, tachycardia |
| Medium | Result |
|---|---|
| Blood Agar (BAP) | Large, smooth, β-hemolytic colonies; golden-yellow pigment (aureus = gold) after room temperature incubation |
| Mannitol-Salt Agar (selective) | Ferments mannitol → yellow colonies; 7.5% NaCl inhibits other organisms |
| Chromogenic Agar (selective) | Characteristic color colonies - used for MRSA screening |
| Test | S. aureus Result | Significance |
|---|---|---|
| Coagulase test | Positive | Key differentiator from CoNS |
| Catalase test | Positive | Differentiates from Streptococcus |
| Mannitol fermentation | Positive | Ferments under aerobic & anaerobic conditions |
| DNase test | Positive | Produces thermonuclease |
| Protein A | Present | Binds IgG Fc region |
| Hemolysis on BAP | β-hemolysis | Due to cytotoxins (especially alpha toxin) |
| MALDI-TOF MS | Identification | Rapid, accurate molecular identification |
| Feature | HA-MRSA | CA-MRSA |
|---|---|---|
| Setting | Hospital-acquired | Community-acquired |
| First reported | Pre-1980s | 1993 |
| SCCmec type | Large cassette | Small cassette |
| Drug resistance | Resistant to nearly ALL antibiotics except glycopeptides | Resistant to β-lactams but often susceptible to non-β-lactam classes |
| Key toxin | Less common | Panton-Valentine Leukocidin (PVL) |
| PVL-associated diseases | Rare | Necrotizing skin/soft-tissue infections; necrotizing pneumonia |
| Common populations | Hospitalized, immunocompromised, post-surgical | Athletes, prisoners, children in contact sports, households |
| Route | Drug(s) |
|---|---|
| IV (serious/invasive) | Vancomycin (drug of choice); Daptomycin, Linezolid, Tigecycline, Telavancin |
| Oral (mild-moderate) | TMP-SMX, Doxycycline/Minocycline, Clindamycin, Linezolid |
| Avoid | Cephalosporins, macrolides, fluoroquinolones (resistance develops readily) |
| Synergistic | Vancomycin + Carbapenems (meropenem) in severe illness |
Sources: Medical Microbiology 9e (Murray et al.), Henry's Clinical Diagnosis and Management by Laboratory Methods, Sherris & Ryan's Medical Microbiology 8e, Rosen's Emergency Medicine, Harrison's Principles 22E