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
Bacteroide species
-Gram negative obligate anaerobes
-Can form endospores
-Membranes contain sphingolipids
-Part of the normal gastrointestinal microbiome
-Can cause many bacterial infections
Smallpox
-Caused by the variola virus
-Causes lesions to form on the skin
-Transmitted through the respiratory system
-Vaccine available
Measles
-Caused by the rubeola virus
-Highly contagious
-Spread via the respiratory system
-Symptoms include symptoms similar to the common cold followed by a rash
-Can lead to encephalitis
German measles
-Caused by the rubella virus
-More mild form of measles
-Usually associated with a rash and a fever
-May lead to encephalitis
-Spread via respiratory system
Chickenpox / Shingles
-Caused by varicella-zoster virus (Herpesvirus)
-Chickenpox is an acute inflammatory disease associated with the development of lesions on the skin
-Can lead to fatal encephalitis and pneumonia
-Spread via the respiratory system
-Virus can remain latent in the body and proceed to cause shingles
Herpes simplex I
-Causes cold sores and can cause corneal infections
-Transmitted orally or via the respiratory system
-Cold sores may appear during times of stress, overexposure to the sun, and hormonal changes
Herpes simplex II
-Causes genital herpes
-Sexually transmitted
-Characterized by some skin lesions in the genital area but may not be associated with symptoms at all
Human papilloma virus
-Most common sexually transmitted infection
-Often not associated with any signs or symptoms
-Can present with the presence of warts
-Vaccine available
-Can lead to cervical cancer
Influenza
-Acute, viral inflammatory disease
-Caused by the influenza virus
-Symptoms include fever, chills, headache, and respiratory symptoms
The common cold
More than 200 viruses are known to cause the common cold
Rabies (Hydrophobia)
-Acute infection
-Caused by a rhabdovirus
-Can be spread via a bite from an infected animal or aerosols of the virus entering the body
-Virus affects skeletal muscles and connective tissues before it travels to the brain
-Characterized by periods of agitation, spasms of the mouth and pharynx, foaming at the mouth
Poliomyelitis
-Caused by the poliovirus
-Usually associated with sore throat, headache, fever, and nausea
-Leads to paralysis in about 1% of cases
-Usually transmitted via contaminated water
-Begins multiplying in the throat and small intestine and moves to the lymph nodes
-Eventually moves to the blood and affects the central nervous system
-Vaccine is commonly used
Viral encephalitis
-Inflammation of the brain caused by an arbovirus
-Arthropod-borne virus
-Mosquitoes transmit the virus to humans
-25% fatality rate
-Associated with chills, headache, fever, confusion, and coma
Hepatitis
-Inflammatory disease of the liver
-Spread by 5 separate viruses leading to several types of hepatitis
-Several types
Hepatitis A
-Spread fecal-oral route
-Usually via ingestion of contaminated water or food, no animal reservoirs
-Virus lives in the human intestinal tract and replicates in the blood
-Virus can survive for days on fomites
-Always an acute infection
Hepatitis B
-Spread via contaminated body fluids (i.e.blood)
-Can be spread via sexual contact and from mother to infant during childbirth
-Chronic and sometimes fulminant infection that can lead to death quickly
-Vaccine available and recommended for those at risk
Hepatitis C
-Spread through direct contact with blood or bodily fluids
-No vaccine available
Infectious Mononucleosis
-Sometimes called ‘the kissing disease’ or ‘the college disease’
-Caused by the Epstein-Barr virus
-Also known as herpes virus 4
-Mostly affects young adults and is sometimes asymptomatic
Cytomegalovirus (Inclusion Disease)
-Caused by cytomegalovirus (Herpesvirus)
-Virus is shed in body secretions such as saliva, urine, and semen
-About 80% of people in the US carry cytomegalovirus
-Symptoms in infants can be very severe including fever, enlargement of the liver and spleen, mental or motor disabilities and death
-Virus can be latent for a period before emerging
Epidemic parotitis (Mumps)
-Infection of the parotid salivary glands
-Symptoms include swelling, pain, painful swelling, and a fever
-Can lead to meningitis, pancreatitis, and deafness
-Can result in inflammation of the testicles in males and rarely sterility
-Can lead to inflammation of the ovaries in women
-Spread via respiratory secretions and saliva
-MMR vaccine available
Human Immunodeficiency Virus
-Contagious disease that leads to compromised immunity
-Transmitted via body fluids
-Leads to AIDS or acquired immunodeficiency syndrome
-There is no cure but there are treatments available
-Spread via sexual contact, contact with infected blood, and from mother to baby
-Often associated with other infections such as pneumonia, fungal infections, and other skin and pulmonary infections
Dermatomycoses
-Infectious fungi are called dermatophytes
-Grow in the keratin of the skin, hair, and nails
-Three types of fungi can cause dermatomycoses
-Trichophyton
-Microsporum
-Epidermophyton
Coccidioidomycosis
-Respiratory disease caused by Coccidioides immitis
-Spores are found in dry, alkaline soils
-Highly virulent mycotic pathogen
-Wind can carry the spores so just passing through endemic areas can cause infection
Histoplasmosis
-Respiratory infection caused by Histoplasma capsulatum
-Found in the bodies of bats and in fecal material from birds
-Acquired via inhalation of airborne spores
-Not spread from person to person
-Can cause COPD which can be fatal
Candidiasis
-Generally only a problem with infants and people with immunocompromised systems
-Can cause systemic infections
-Candida albicans and Candida auris are common strains
-Often multi drug resistant
Cryptococcosis (Fungal Meningitis)
-Caused by Cryptococcus neoformans
-Often leads to secondary fungal infections
-Causes a chronic form of meningitis
Pneumocystis Pneumonia (PCP)
-Pneumonia caused by Pneumocystis jirovecii
-Common in immunosuppressed persons
-Often multi-drug resistant
-Commonly exists in the lungs of animals like dogs, cats, horses, and rodents
-Can lead to respiratory failure
Malaria
-Biological vector is the anopheles mosquito
-Caused by a Plasmodium species
-P. falciparum
-P. vivax
-P. ovale
-P. malariae
-Protozoan multiplies in the liver and the red blood cells
-Symptoms begin with fever and chills
-Eventually can lead to anemia and hypertrophy of the liver and spleen
Toxoplasmosis
-Caused by Toxoplasma gondii
-Common cause of foodborne illness
-Contained in contaminated water or foods that are not properly cooked or processed
-Contaminated cat feces can also spread toxoplasmosis
-Forms cysts throughout the body in muscle tissue, the heart, and brain
-More severe in immunocompromised patients
-Can be fatal in these cases
Giardiasis
-Caused by Giardia lamblia
-Found in water supplies (both natural and in cities)
-Can be spread via the fecal-oral route but is usually spread through contaminated water
-Results in gastrointestinal symptoms and usually resolves itself within a few weeks
-Can become chronic
Creutzfeldt-Jakob Disease (CJD)
-Prion
-Causes spongiform degeneration of the brain
-Long incubation period
-Can be transmitted or inherited
-Usually fatal within one year of the onset of symptoms
-Very rare disease but no treatment is available
