177.1 🎓 醫孞生版

177.1.0.1 📌 䞀頁重點

  • Stenotrophomonas maltophilia:
    • Gram - rod, oxidase -, non-lactose, motile
    • 醫院 water + skin colonizer; immunocompromise + ventilator + line + 化療
    • Intrinsic MDR (almost all β-lactams R, FQ R variable)
    • TMP-SMX 驖遾 (only consistently active)
    • Alt: minocycline, levofloxacin, ceftazidime (if S), tigecycline
  • Burkholderia cepacia complex (BCC):
    • 倚 species (B. cenocepacia, B. multivorans most clinical)
    • CF chronic colonization → “cepacia syndrome” (fulminant sepsis + pneumonia)
    • Intrinsic MDR — TMP-SMX, ceftazidime, meropenem, minocycline alternatives
    • Lung transplant — historically contraindication (some center reversed)
  • Burkholderia pseudomallei → Melioidosis:
    • Thailand, N Australia, SE Asia, increasingly tropics (climate change)
    • Soil + freshwater
    • “Great mimicker” — multi-organ abscess, pneumonia, septic shock
    • DM, alcoholism, CKD = highest risk
    • Treatment: Intensive phase: ceftazidime or meropenem ≥ 2 wk IV → Eradication phase: TMP-SMX ≥ 12 wk
  • Burkholderia mallei → Glanders: equine zoonosis, bioterror Category B
  • Achromobacter, Ralstonia, Pandoraea, Cupriavidus: rare opportunistic

177.1.0.2 1⃣ Stenotrophomonas maltophilia

177.1.0.2.1 Microbiology
  • Gram - rod, oxidase NEG (vs PsA +)
  • Motile
  • 倚 colors / no pigment
  • Non-lactose
177.1.0.2.2 Habitat
  • Soil + water + plant + skin
  • 醫院 sinks, dialysate, IV solution contamination
  • Immunocompromise + ICU vent + line
177.1.0.2.3 臚床
  • Bacteremia (line, immunocompromise — leukemia, BMT, ICU)
  • Pneumonia (VAP, CF chronic, HSCT)
  • UTI, wound, meningitis (post-NSx), endocarditis (rare)
  • 倚 mortality 圚 immunocompromise
177.1.0.2.4 Treatment
  • Intrinsic R: most β-lactams (carbapenems too — Acinetobacter-like AmpC + L1 metallo β-lactamase)
  • TMP-SMX 驖遾 (高 sensitivity, intracellular concentration good)
  • Minocycline — good alternative
  • Levofloxacin — alternative if S
  • Ceftazidime — varying S
  • Cefiderocol — alternative for difficult cases
  • Tigecycline — wound / abdominal but not bacteremia
  • Combination sometimes for severe (TMP-SMX + levo + minocycline)
177.1.0.2.5 Pregnancy
  • TMP-SMX contraindicated 3rd trimester (kernicterus risk in neonate)
  • Alternative: minocycline (caution), levofloxacin

177.1.0.3 2⃣ Burkholderia cepacia Complex (BCC)

177.1.0.3.1 Microbiology
  • Gram - rod, oxidase +, motile, lactose +
  • 倚 species (B. cenocepacia, B. multivorans, B. vietnamiensis, etc.)
  • B. cenocepacia (genomovar III) — most aggressive
177.1.0.3.2 流行病孞
  • Soil + water + plants
  • 醫院 contaminations (mouthwash, nebulizer, etc.)
  • CF most clinically relevant — chronic colonization
  • Person-to-person CF transmission (segregation between CF patients important)
177.1.0.3.3 臚床
  • CF Chronic Colonization — FEV1 decline, exacerbations
  • “Cepacia Syndrome” — fulminant pneumonia + sepsis + 高 mortality in CF
  • Lung transplant — B. cenocepacia historical contraindication; some centers accept B. multivorans
  • Non-CF: ICU, immunocompromise, granulomatous disease
177.1.0.3.4 Treatment
  • Intrinsic R: amino glycoside, polymyxin
  • Sometimes S: TMP-SMX, ceftazidime, meropenem, minocycline, levofloxacin
  • AST always — variable S
  • Combination therapy in severe (TMP-SMX + meropenem + tobramycin)
  • Difficult to eradicate from CF lung

177.1.0.4 3⃣ Burkholderia pseudomallei (Melioidosis)

177.1.0.4.1 Microbiology
  • Gram - rod, “safety pin” bipolar staining (像 Yersinia, plague family)
  • Oxidase +
  • Soil + freshwater organism
  • Hardy — survives extreme conditions
177.1.0.4.2 流行病孞
  • Endemic Thailand, N Australia, Malaysia, Singapore, Vietnam, India, S China, Sri Lanka, Taiwan rare
  • Climate change: expanding to Africa, Americas, Pacific (Hurricane Katrina, Hurricane Maria, recent outbreaks)
  • 2021 US outbreak — aromatherapy spray from S Asia
  • Exposure: soil contact, agricultural work, monsoon season, contaminated water
  • DM, alcoholism, CKD, thalassemia = 高 risk
177.1.0.4.3 臚床 — “Great Mimicker”
  • Pneumonia (mild → fulminant)
  • Septicemia (high mortality 40%+)
  • Multi-organ abscess: liver, spleen, lung, prostate (men), parotid (Asian children)
  • Genitourinary abscess: testicular (men)
  • Soft tissue / skin abscess
  • Bone / joint
  • Neurologic: encephalitis, brain abscess
  • Latent: years after exposure, “Vietnamese time bomb” (returning veterans)
  • 5-25% recurrence rate
177.1.0.4.4 Treatment — Two Phases
177.1.0.4.5 Phase 1: Intensive
  • Ceftazidime 2 g IV q6h (preferred 因 cost in endemic country)
  • OR Meropenem 1 g IV q8h (severe, ICU, neuro, septic shock)
  • Duration: ≥ 2 weeks (longer if abscess / osteo / CNS)
  • May add TMP-SMX for severe / CNS / osteo
177.1.0.4.6 Phase 2: Eradication
  • TMP-SMX 4 tabs (DS) PO bid × 12 wk
  • Long duration prevents relapse
  • Doxycycline alt
  • Compliance important
177.1.0.4.7 Mortality
  • ~ 10% Australia, 30-40% Thailand (with treatment)
  • Highest in septic shock
177.1.0.4.8 Vaccine
  • In development; not yet available
  • Public health: barrier (boots, gloves) for agricultural workers in endemic regions

177.1.0.5 4⃣ Burkholderia mallei (Glanders)

  • Equine zoonosis (horse, mule, donkey)
  • Rare human disease (lab exposure, animal contact)
  • Bioterror Category B
  • Cutaneous, pulmonary, septicemic, chronic forms
  • Treatment: same as melioidosis (ceftazidime/meropenem → TMP-SMX)

177.1.0.6 5⃣ Other Nonfermenters

177.1.0.6.1 Achromobacter xylosoxidans
  • 偶 ICU + CF
  • Bacteremia, pneumonia
  • Treatment: pip-tazo, ceftazidime, mero, TMP-SMX (AST-driven)
177.1.0.6.2 Ralstonia + Cupriavidus
  • Rare; contaminated IV solutions outbreaks
  • TMP-SMX, FQ, ceftazidime
177.1.0.6.3 Chryseobacterium / Elizabethkingia
  • E. meningoseptica — neonatal meningitis
  • Multi-R; vanco + rifampin + cipro (atypical combos)
177.1.0.6.4 Pandoraea
  • CF colonization
  • Rare clinical