Week 8 Specific Organisms Flashcards
Mycoplasma pneumoniae
-Aerobic
-Resistant to many antibiotics
-Slow growing
-Egg-shaped colonies that adhere easily to surfaces in the respiratory and urogenital tract
-Spread via aerosol droplets
-Can cause bronchitis, pharyngitis, or atypical pneumonia
Rickettsia prowazekii
-Arthropod vector is human body lice
-Humans are the natural reservoir
-Found primarily in crowded areas with poor sanitation
-Causes epidemic typhus or louse-borne typhus
-high mortality rate of about 40%
Rickettsia typhi
-Causes endemic typhus
-Symptoms similar to but less severe than those associated with epidemic typhus
-Also rarely associated with a rash
-Transmitted from the rat flea to humans
Rickettsia rickettsii
-Parasite found in species of ticks
-Causes rocky mountain spotted fever
-Prevalent in the southeastern US and Appalachia
-Causes a rash on the soles of the feet and the palms that usually begins on the extremities, headache, muscle aches, fever, nausea, and vomiting
Coxiella burnetii
-Transmitted via the air from animal to animal via tick bites
-Humans can become infected by consuming contaminated milk from infected cattle or inhaling aerosol droplets when in close proximity to infected cattle
-Causes Q fever
-Associated symptoms include fever, headache, malaise, muscle pain, and nausea
Chlamydia psittaci
-Gram negative obligate parasite
-Causes psittacosis (parrot fever)
-Can be contracted from birds such as chickens, pigeons, ducks, and turkeys and is transmitted via inhalation of aerosolized microbes from bird droppings
-Form of pneumonia that causes fever, headache, and chills and other flu-like symptoms
Chlamydia trachomatis
-Causes inflammation of the urinary tract and a sexually transmitted disease known as lymphogranuloma venereum (chlamydia)
-Can cause blindness and a lesion called a trachoma if the bacteria is spread to the eye
-Spread from person to person, person to fomite, and fly to person and is shed in the feces of infected persons
-Can lead to pelvic inflammatory disease, birth defects, and infertility and increase the chance of acquiring HIV if exposed
Vibrio cholerae
-Gram negative bacillus with a single flagellum
-Grows in the small intestine and produces an enterotoxin
-Toxin results in high electrolyte levels and the loss of fluids can lead to shock
-Found in contaminated water
-Causes Asiatic cholera or epidemic cholera
Yersinia pestis
-Gram negative bacillus
-Transmitted from rat to flea to human or from other infected animal to human
-Responsible for the bubonic plague (also known as “the Black Death” because of the dark hemorrhage spots presented with the disease)
-Death occurs in less than a week in untreated cases
-Causes hyperplastic growth of the lymph nodes
-Can also cause pneumonic plague
Klebsiella pneumoniae
-Part of the normal gastrointestinal flora
-Resistant to phagocytosis
-Gram negative bacillus
-Often causes respiratory tract infections
Clostridium botulinum
-Gram positive anaerobic bacillus
-Produces botulinum toxin which causes food poisoning
-Causes the release of acetylcholine to be blocked and may result in death
-Causes botulism which results in paralysis, cardiac failure, and respiratory failure
Bacillus anthracis
-Gram positive aerobe
-Found in water and soil
-Can form endospores and are capable in surviving in harsh environments
-Responsible for causing anthrax in humans
-Usually associated with contact with farm animals
-May be cutaneous, inhalation, or gastrointestinal anthrax
-Not contagious; must be spread via the inhalation or ingestion of B. anthracis spores
Hemophilus influenzae
-Gram negative and highly virulent
-Produces a capsule and contains antigens that paralyze cilia in the respiratory tract
-Causes influenzal meningitis
Proteus species
-Highly motile saprophytic bacteria found in the human gastrointestinal tract
-Commonly cause secondary infections of burns
-Colonies have a unique odor described as “burned chocolate”
-Common species include P. vulgaris which is a common contributor to decomposition and P. mirabilis
Pseudomonas species
-Gram negative aerobic bacillus
-Often resistant to antibiotics
-Can cause infections of burns themselves or associated secondary infections
-Commonly attributed to P. aeruginosa
Shigella species
-Anaerobic gram negative bacilli
-Part of the normal gastrointestinal flora
-Spread via the fecal-oral route (flies, poor hygiene, contaminated food/water)
-Responsible for causing shigellosis or bacillary dysentery
-Common species include S. sonnei and S. flexneri
Leptospira interrogans
-Spirochete
-Causes leptospirosis
-Usually a disease of animals but can cause liver and kidney disease in humans
-Spread via contaminated waste of infected animals or contaminated water/soil
-Dogs, rats, and other rodents are common reservoirs
Escherichia coli
-Opportunistic bacillus that is part of the normal gastrointestinal flora
-Cause enteritis
-Characterized by diarrhea, cramps, malaise, and fever
-Spread via the fecal-oral route
Campylobacter jejuni
-Gram negative bacillus
-Non-spore-forming
-May cause gastroenteritis
-Transmitted via contact with infected pets; may also be sexually transmitted, ingested in contaminated water or dairy products, or ingested in improperly cooked poultry
Helicobacter pylori
-Can cause ulcers
-Some pain medications increase the likelihood of ulcer formation
-May also be associated with gastroadenocarcinoma