Microbial Morphology and Reservoirs: Bacteria and Pathogens

Mycobacterium Tuberculosis (Morphology)

GP-like rods

Mycobacterium Leprae (Morphology)

GPR

escherichia coli (E. coli) (Morphology)

GNR

ETEC (enterotoxigenic) (Morphology)

GNR

STEC (Shiga toxin) (Morphology)

GNR

Shigella dysenteriae (Morphology)

GNR

Salmonella typhimurium (Morphology)

GNR

Salmonella typhi (Morphology)

GNR

Vibrio cholerae (Morphology)

GNR Curved

Vibrio vulnificus (Morphology)

GNR Curved

campylobacter jejuni (campy) (Morphology)

GNR short curved

helicobacter pylori (Morphology)

GNR curved, polar flagella

mycoplasma pneumoniae (Morphology)

NO cell wall, just a membrane

Rickettsia rickettsii (Morphology)

GNR (obligate intracellular)

Rickettsia prowazekii (Morphology)

GN coccobacillus

pseudomonas aeruginosa (Morphology)

GNR

leionella pneumophila (Morphology)

GNR

Borrelia burgdorferi (lyme disease) (Morphology)

GN spirochete

Yersinia pestis (Morphology)

GNR

Francisella tularensis (Morphology)

GN coccobacillus

Bacillus anthracis (Morphology)

GPRs in chains

clostridium botulinum (Morphology)

GPR (tennis racquet)

clostridium tetani (Morphology)

GPR (tennis racquet)

clostridiioides difficile (Morphology)

GPR

Bodetella pertussis (whooping cough) (Morphology)

GN coccobacillus (rod with rounded ends)

haemophilus influenzae (serotype b) (Morphology)

GN coccobacillus (rod with rounded ends)

Mycobacterium Tuberculosis (Reservoir)

Human active cases

Mycobacterium Leprae (Reservoir)

human cases, armadillos

escherichia coli (E. coli) (Reservoir)

lower GI commensals, environment

ETEC (enterotoxigenic) (Reservoir)

infected humans

STEC (Shiga toxin) (Reservoir)

animals colonized by STEC

Shigella dysenteriae (Reservoir)

human infected/carrier cases

Salmonella typhimurium (Reservoir)

human/animal GI tracts

Salmonella typhi (Reservoir)

human-specific, chronic carriers

Vibrio cholerae (Reservoir)

human cases, contaminated water

Vibrio vulnificus (Reservoir)

warm, brackish waters

campylobacter jejuni (campy) (Reservoir)

animal GI tracts, esp chickens

helicobacter pylori (Reservoir)

humans

mycoplasma pneumoniae (Reservoir)

human carriers (kids esp)

Rickettsia rickettsii (Reservoir)

ticks

Rickettsia prowazekii (Reservoir)

humans, flying squirrels

pseudomonas aeruginosa (Reservoir)

moist environments

leionella pneumophila (Reservoir)

aquatic environments

Borrelia burgdorferi (lyme disease) (Reservoir)

rodents

Yersinia pestis (Reservoir)

rodents

Francisella tularensis (Reservoir)

rabbits, squirrels, beaver

Bacillus anthracis (Reservoir)

soil

clostridium botulinum (Reservoir)

soil

clostridium tetani (Reservoir)

soil

clostridiioides difficile (Reservoir)

human GI, asymptomatic

fomites in environment

Bodetella pertussis (whooping cough) (Reservoir)

asymptomatic human carrier

haemophilus influenzae (serotype b) (Reservoir)

asymptomatic human carrier

Mycobacterium Tuberculosis (Transmission)

Respiratory, low infectious dose

Mycobacterium Leprae (Transmission)

skin breaks, inhalation (low infectivity)

escherichia coli (E. coli) (Transmission)

fecal-oral

ETEC (enterotoxigenic) (Transmission)

fecal-oral

STEC (Shiga toxin) (Transmission)

food-borne

Shigella dysenteriae (Transmission)

fecal-oral

Salmonella typhimurium (Transmission)

fecal-oral

Salmonella typhi (Transmission)

fecal-oral

Vibrio cholerae (Transmission)

fecal-oral; poor sewage/water infrastructure

Vibrio vulnificus (Transmission)

food-borne (raw shellfish), skin breaks/wounds

campylobacter jejuni (campy) (Transmission)

fecal-oral, contaminated food

helicobacter pylori (Transmission)

fecal-oral, mouth-to-mouth

mycoplasma pneumoniae (Transmission)

respiratory, PtP, tissue culture contaminant

Rickettsia rickettsii (Transmission)

ticks

Rickettsia prowazekii (Transmission)

PtP, body lice

pseudomonas aeruginosa (Transmission)

airborne, biofilms

leionella pneumophila (Transmission)

aerosol inhalation from cooling towers, misters, dehumidifiers

Borrelia burgdorferi (lyme disease) (Transmission)

deer ticks

Yersinia pestis (Transmission)

fleas

Francisella tularensis (Transmission)

ticks/deer flies, handling infected carcasses

Bacillus anthracis (Transmission)

spores into skin wound, breaks in skin, inhalation, ingestion

clostridium botulinum (Transmission)

spores (honey, food-borne)

clostridiioides difficile (Transmission)

dysbiosis of GI, fecal-oral ingestion of spores

Bodetella pertussis (whooping cough) (Transmission)

respiratory

haemophilus influenzae (serotype b) (Transmission)

respiratory

clostridium tetani (Transmission)

traumatic implantation of spores

Mycobacterium Tuberculosis (Clinical Presentation)

Primary: mild, asymptomatic, spontaneous healing

Latent: infection contained in granulomas

Secondary: reactivation of latent phase; chronic cough, cachexia, systemic manifestation, extrapulmonary spread

Pott's disease/spinal TB: death of IVD due to infection, causes kyphosis (outward curvature of spine)

Mycobacterium Leprae (Clinical Presentation)

Leprosy:

1. Tuberculoid: small number of flat, anesthetic skin lesions

2. lepromatous: poor containment, widespread skin leasions, can cause permanent nerve, skin, eye, or limb damage (crippled hands)

escherichia coli (E. coli) (Clinical Presentation)

UTIs:

- upper (kidney): pyelonephritis (causes dysuria and cloudy urine)

- lower (bladder): cervicitis, urethritis, prostatitis for men

Neonatal meningitis:

- contracted if exposed during delivery

diarrhea:

- ETEC and STEC

ETEC (enterotoxigenic) (Clinical Presentation)

nausea, loose stool, vomiting, fever

STEC (Shiga toxin) (Clinical Presentation)

bloody diarrhea that can progress to HUS

Hemolytic uremic syndrome: characterized by triad of symptoms

1. thrombocytopenia (platelet consumption)

2. hemolytic anemia (RBC lysis)

3. hematuria: urea buildup from clogged glomeruli

Shigella dysenteriae (Clinical Presentation)

shigellosis: severe bloody, mucousy diarhhea that resolves in about a week

risk for HUS if strain creates Stx

Salmonella typhimurium (Clinical Presentation)

nausea, vomiting, abdominal cramps, fever, diarrhea (salmonella)

Salmonella typhi (Clinical Presentation)

typhoid fever: severe systemic illness

persistent bacteremia: can cause hemorrhage of intestines

carrier state: forms biofilm on lining of gall bladder and is then shed into GI tract for weeks

Vibrio cholerae (Clinical Presentation)

rapid onset

abdominal fullness and discomfort, vomiting

rushes of peristalsis: voluminous, watery stools (rice-water stools)

life-threatening dehydration

Vibrio vulnificus (Clinical Presentation)

diarrhea

blistering cellulitis: can progress to sepsis or necrotizing fasciitis

campylobacter jejuni (campy) (Clinical Presentation)

campylobacteriosis: watery diarrhea that can progress to bloody

sequelae: Guillian-Barre syndrome, tingling/weakness of the legs that can spread to arms and upper body; can take weeks to years to recover (similar mechanism to ARF)

helicobacter pylori (Clinical Presentation)

antrum (stomach mucosa) infection, causes gastric ulcers and gastritis from bacterial overgrowth

risk of gastric cancer

mycoplasma pneumoniae (Clinical Presentation)

walking pneumonia: fever, cough, shortness of breath; most cases tracheobronchitis (upper respiratory infection)

smoldering infection over several weeks (very slow onset is clinical cue)

Rickettsia rickettsii (Clinical Presentation)

rocky mountain spotted fever: fever, headache, vomiting, joint pain, petechiae

centripetal rash (moves inward)

vascular collapse can be fatal

Rickettsia prowazekii (Clinical Presentation)

epidemic typhus: fever with confusion and stupor

centrifugal rash (spreads to extremities except hands and feet)

pseudomonas aeruginosa (Clinical Presentation)

opportunistic pathogen: takes advantages of breaches in barrier and causes lung, skin, or eye infections (hospital acquired)

lung: pneumonia

skin: hot tub rash and green nail syndrome (mild), burn wounds (severe

eye: keratitis (corneal infection, contact lenses)

leionella pneumophila (Clinical Presentation)

severe: legionnaires' disease, severe pneumonia

mild: pontiac fever (flu-like)

Borrelia burgdorferi (lyme disease) (Clinical Presentation)

localized: bulls-eye rash at bite site, flu-like symptoms

Disseminated: additional skin lesions, possible severe bradyarrhymias that can cause AV block)

post-treatment Lyme disease syndrome (PTLDS): ontroversial; brain fog, fatigue (lingering symptoms)

Yersinia pestis (Clinical Presentation)

plague: black death

sylvatic plague in animals

bubonic plague: infection of regional LNs from flea bite

septicemic plague: bactermia and sepsis if LNs fail to stop infection; ischemic necrosis from clots (hypercoagulability)

pneumonic plague: extremely infectious as it spreads to lungs, dead within 2-3 days

Francisella tularensis (Clinical Presentation)

ulceroglandular form: skin lesions, axillary or inguinal lymphadenopathy

pneumonic form: moves to lung via hematogenous spread, most severe fever, headache, muscle aches, weakness

Bacillus anthracis (Clinical Presentation)

cutaneous anthrax: spores germinate into bacteria, forms black eschar with red border

inhalational anthrax: life-threatening, pulmonary hemorrhage

gastrointestinal anthrax: consuming infected meat, lesions in GI tract causing hemorrage and perforation

clostridium botulinum (Clinical Presentation)

botulism: flaccid paralysis; muscle weakness, progressing to respiratory paralysis from spreading BTX, constipation in infants (muscularis propria)

adults: wound botulism, produces BTX locally