Bacterial Flashcards
Actinomycosis
• Causative organism: (an anaerobic gram-positive rod)
Source of infection
Actinomyces israelii
is “endogenous,” e.g., oral flora
Nocardia brasilensis,Actinomadura madurae, A. pelletieri, and Streptomyces somaliensis
Actinomycetoma Aerobic filamentous bacteria
“exogenous,” e.g., soil
Anthrax
• Causative organism: Bacillus anthracis,
• gram-?
Primarily caused
-positive spore-forming rod
contact with infected wild or domestic animals, or their products (e.g., wool, goat, animal hides, bones, etc.)
B. anthracis has two exotoxins:
• edema toxin and lethal toxin
– Edema toxin = Edema Factor (EF) + Protective Antigen(PA)
– Lethal toxin = Lethal Factor (LF) + PA
–
Three clinical forms: anthrax
Inhalational, Gastrointestinal, and Cutaneous
•
Anthrax Treatment:
- ) Bioterrorism associated: Ciprofloxacin or Doxycycline
2. ) Conventional anthrax: Penicillin
EF causes
increase
gelatinous edema
(cAMP) levels
LF causes shock and death in disseminated anthrax via
the release of tumor necrosis
factor-alpha (TNF-α) and interleukin-1β (IL-1β)
PA is responsible for entry of exotoxins into the cell
receptor-mediated endocytosis.
antibodies to PA
Bartonellosis
Type?
aerobic, gram-negative bacilli
Cat-Scratch Disease
B. henselae
transmission
Resolutn
Cat flea-Ctenocephali-
des felis (from cat to cat only);
humans infected by catbite or scratch
Spontaneous resolutionin the majority of cases
Bacillary Angiomatosis caused
Treat with
B. henselae
B. quintana
ErythromyciDoxycycline
Trench Fever caused , vector, rx
queen of the trenches with the human body louse
B. quintana
Human body louse - Pediculus humanus corporis
Doxycycline Erythromycin
Oroya Fever aka
(Carrion’s
Disease) Verruga Peruana
Oroya Fever Chloramphenicol
(because of frequentsuperinfection with
Salmonella)
Lyme Disease
B. burgdorferi
Vector lyme
Damn the lyme
Ixodes dammini* (Northeast U.S.) Ixodes pacificus (Western U.S.) Ixodes ricinus (Europe)
Lyme clinical
Erythema Migrans
• Acrodermatitis
Chronica Atrophicans
Lyme rx
Doxycycline 100 mgpo bid for 14-21 days
(Pregnancy, Children
<9: Amoxicillin)
Relapsing clinical features
Paroxysmal fevers (2 episodes) • Headache • Lymphocytoma • Mylagias • Erythematous or petechial macules on trunk, and extremities
Relapsing fever Louse-Borne
vs tick borne rx
Doxycycline 100 mg pox 1 dose vs
Doxycycline 100 mg po
bid for 7 days
Relapsing fever- Louse-Borne
Tick-Borne
(Africa, South America)
(Western United
States)
B. duttonii
B. hermsii
Tick-Borne Relapsing fever
Soft-bodied ticks
B. recurrentis
Relapsing fever- Louse-Borne
Human body louse (Pediculus humanus)
• Causative organisms: S. aureus, P. aeruginosa, E. coli, and Proteus species
Botryomycosis
Botryomycosis
light microscopy
• Granular bodies
Characteristic features: “Gunmetal gray,” infarcts with surrounding erythema
Causative organism: – a gram-positive rod
• Typically occurs in handlers of contaminated raw fish or meat (e.g., fishermen, butchers)
• Characteristic features: A tender, well-demarcated, violaceous lesion with raised margins
and central clearing, typically on the hand or finger
• Treatment: Penicillin
ecthyma Gangrenosum
ecthyma Gangrenosum Causative organism:
• Treatment:
Pseudomonas aeruginosa septicemia Intravenous
Erysipelothrixw rhusiopathiae
at risk
contaminated raw fish or meat (e.g., fishermen, butchers)
Erysipeloid treatment
•: Penicillin
Glanders
• Causative organism:
• Disease caused by contact with
Burkholderia mallei
infected horses
Glanders Characteristic features:
Ulcerated nodule with regional lymphadenopathy
•Glanders Treatment:
Imipenem or doxycycline
Neisseria meningitides
at risk
treatment
a gram-negative diplococcus
young children and patients with complement deficiencies
IV-Penicillin or ceftriaxone
Pitted Keratolysis
• Causative organism:
Micrococcus sedentarius
Rat-bite Fever (Haverhill Fever)
• Causative organism:
• Infection acquired from
• Treatment:
Streptobacillus moniliformis
rodents or contaminated food
Penicillin
Fever, arthralgias, rash (nonspecific erythematous macules or
papules, which can become generalized)
Rat-bite Fever (Haverhill Fever)
• Characteristic features
Klebsiella pneumoniae rhinoscleromatis
• Characteristic features:
histopath
Rhinoscleroma
Hypertrophic plaques on external nares•
Mikulicz cells
Actinomycetoma source
exogenous,” e.g., soil
Oroya fever caused by
Transmitted via
Oroya does a bacciliformis. Dance around sandfly
B. bacilliformis
Sandfly - Lutzomyia verrucarum
