Bacterial Infections

Characteristics of Actinomyces spp

-gram (+)

-filamentous-shaped

-anaerobic

Infections of Actinomyces spp

-canaliculitis (sulfur granules → dacryoliths)
-dacryocystits
-chronic mucopurulent conjunctivitis, oropharynx abscess
-mycetoma (cutaneous infection)
-cervicofacial actinomycosis (infection of face and neck, aka "lumpy jaw")
-A. israelii colonizes the oropharynx → most common cause of actinomycosis in humans

Characteristics of Mycobacterium tuberculosis

-gram (+)
-rod-shaped
-aerobic
-acid-fast

Infections of Mycobacterium tuberculosis

-primary lung infection (TB)

-scleritis

-chorioretinitis

-phlyctenular keratoconjunctivitis

-interstitial keratitis (inflammation and vascularization of the corneal stroma without endothelial or epithelial involvement)

-uveitis

Characteristics of Bacillus anthracis

-gram (+)

-rod-shaped

-aerobic

-spore-forming

Infections of Bacillus anthracis

cutaneous, pulmonary, and GI tract anthrax

Characteristics of Clostridium difficile

-gram (+)

-rod-shaped

-anaerobic

-spore-forming

Infections of Clostridium difficile

pseudomembrane colitis with bloody diarrhea

Characteristics of Moraxella lacunata

-gram (-)

-coccobacillus

-aerobic

-oxidase (+)

-catalase (+)

-α-hemolytic

Infections of Moraxella lacunata

-angular blepharoconjunctivitis
-conjunctivitis
-endocarditis
-keratitis

Characteristics of Helicobacter pylori

-gram (-)

-spiral-shaped

-facultative anaerobic

-urease (+) → promotes ammonia production to neutralize stomach acidity

-multiple flagella

-ubiquitous

-acquired by ingestion, person-to-person spread

Infections of Helicobacter pylori

-duodenal & stomach acid
-gastric mucosa cancer
-GERD

Characteristics of Borrelia burgdoferi

-neither gram (-) nor gram (+) → doesn't stain well

-spiral-shaped

-microaerophilic

Infections of Borrelia burgdoferi

-Lyme disease

-early stage: follicular conjunctivitis

-intermediate stage: interstitial or ulcerative keratitis with peripheral neovascularization

-late stage: optic neuritis with CN palsies

Characteristics of Mycoplasma pneumoniae

-gram (-)

-small & pleomorphic

-facultative anaerobic

-no cell wall

-sterols in cell membrane

-transmission via aerosols from infection persons and asymptomatic carriers

-no target for β-lactams → but responds to macrolides, tetracyclines, and quinolones

Infections of Mycoplasma pneumoniae

-atypical (walking) pneumonia
-tracheobronchitis
-conjunctivitis
-optic neuritis
-papilledema

Characteristics of Rickettsia rickettsii

-gram (-)

-small coccobacillus

-aerobic

-intracellular obligate

-transmission via ticks

Infections of Rickettsia rickettsia

-rocky mountain spotted fever

-optic nerve edema

-optic neuritis

-conjunctivitis

-chorioretinitis

-conjunctival petechiae

-subconjunctival hemorrhages

-keratitis

-non-granulomatous anterior uveitis

Characteristics of Treponema pallidum

-gram (-)

-spiral-shaped

-microaerophilic

Infections of Treponema pallidum

-neurosyphilis (Argyll-Robertson Pupil)
-syphilis: primary → chancre sore; secondary → mucocutaneous rash; tertiary → gumma/granuloma
-ocular manifestations: conjunctivitis, episcleritis, scleritis, keratitis, granulomatous or non-granulomatous anterior uveitis, necrotizing retinitis, chorioretinitis, retinal vasculitis, and optic neuritis