BIO220 Lecture Exam 7 - Ch 21-25

Treponema pallidum

spirochete, causes syphilis, can be vertically transmitted to fetus, treated with penicillin. Can be passed congenitally (passed from mother to child) - children have characteristic appearance of teeth, can test for it using serology and/or microscopic examination of fluid from chancre sore, not culturable.

Syphilis - clinical stages

1. Primary (chancre sores)

2. secondary (rash that can be on palms of hands and bottoms of feet), and

3. tertiary (neurological damage, may have irregularly-shaped pupils)

Leptospira interrogans

contract by contact with infected urine, typically from wild animals, can have outbreaks with flooding, doesn't affect many people in the U.S. but can affect domestic livestock if water/feed get contaminated by wild animals, causes sudden high fever, organs targeted.

Borrelia burgdorferi

causes Lyme disease, transmitted by ticks, humans are accidental host, can cause characteristic bull's eye rash in 50% or more of cases (due to pathogen's ability to migrate out through the tissues from the initial tick bite and the host's attempt to fight the disease), can affect organs, not fatal, can cause neurological effects like a stiff neck (which you also may see with meningitis caused by other organisms), prevented by insect repellant with DEET, treated with tetracycline.

Vibrio cholera

causes cholera (diarrheal disease - causes "rice water" stool) due to dirty water, produces a cholera toxin, comma-shaped organism, ID is 100,000,000 cells, treated by administering clean water, electrolytes and tetracycline if necessary, vaccine available. This may be seen in immigrant patients or those who have traveled to a developing country.

Vibrio parahaemolyticus and vulnificus

cause gastroenteritis from raw oysters and seafood, more serious in liver disease patients, treatment is usually fluid and electrolyte replacement, antimicrobials if necessary in more serious cases.

Helicobacter pylori

causes stomach ulcers, can withstand very acidic conditions of the stomach, treatable by antibiotics (though it often returns), curved-shaped organism

Rickettsia rickettsii, other Rickettsia spp., and Erlichia

causes Rocky Mountain Spotted Fever (R. rickettsii), typhus, erlichiosis, transmitted by ticks, fleas, mites, lice, symptoms may vary and include fever, rash, nausea, heachache, may damage heart and CNS, can have high fatality, difficult to diagnose - based on clinical symptoms and serology, treatment with tetracycline or doxycycline.

Coxiella burnetti

causes Q fever, cattle, sheep, and goats are primary reservoirs, transmission is usually from airborne barnyard dust,

10-20% of veterinarians, farmers, etc. have antibodies to the pathogen, suggesting past infection

Bartonella

causes Cat-Scratch Fever, Trench Fever (spread by lice), symptoms include fever, enlarged lymph nodes, papule or pustule at cat scratch site, diagnose by growth on enriched media after 1-3 weeks, serology, treat with azithromycin, aminoglycosides, etc.

Chlamydia trachomatis

causes Chlamydia STD and sterility, can also infect the eyes of newborns, human reservoir.

Chlamydophila psittaci

causes pneumonia or flu-like disease, transmitted by birds

Mycoplasma pneumoniae

wall-less organism, pleomorphic (can change shape because it has no wall), causes atypical pneumonia = "walking pneumonia," can clear up on its own or be treated with antibiotics

unique virulence factor of true fungal pathogens

thermal dimorphism (ability to grow as yeasts at 37◦C and as molds at 30◦C)

Amphotericin B

Antifungal used for fungal infections - especially those that are severe/systemic. Administered by IV

Histoplasma capsulatum

most common true fungal pathogen, causes histoplasmosis, grows in moist high nitrogen soil like that found near chicken farms, endemic to this area, can become systemic chronic disease, treated with amphotericin B, ketoconazole, spores inhaled into the lungs and germinate there, prevent by wearing a mask.

Sporothrix

causes rose gardener's disease, comes from the soil and happens when someone has skin pricked by rose thorns and soil gets into wound

Cutaneous mycoses

-alternate names: dermatophytes, ringworm & tinea

fungal disease that affects hair, skin, and nails

Candida albicans

yeast, most common opportunistic mycosis,

causes everything from superficial vaginal thrush (mouth infection, common in babies) and other yeast infections to fatal systemic disease,

important cause of nosocomial infections (causes 70% of them), treated by topical creams for superficial infections, treat systemic infections with amphotericin B or fluconazole

Cryptococcus neoformans

-spread by pigeons,

-common in AIDS patients, inhalation of spores into lungs causes cough and fever, can infect brain and cause death, treat with amphotericin B and fluconazole

Pneumocystis (carinii) jiroveci

-causes most prominent opportunistic infection in AIDS patients called PCP (Pneumocystic carinii pneumonia), secretions blocks breathing, fatal if not controlled

Stachybotrys chartarum

toxic black mold (note that not all mold that is black in color is this one - testing needed to confirm), causes sick building syndrome with hematological and neurological damage.

Trichomonas vaginalis

a top STD that causes discharge in both sexes, particularly foul-smelling in females, but 50% of cases are asymptomatic, treatment with metronidazole

Giardia lamblia

source is contaminated water, causes diarrheal disease, shed intermittently in feces, water treatment by boiling, ozone, iodine, or filtering will prevent, treatment with metronidazole

Trypanosoma cruzi

Chagas disease, endemic to Central and South America, bug vector, there are approx. 300,000 cases in the U.S. now almost all obtained from endemic countries (Mexico, Central and South America), bug vector, but also congenital, and contaminated blood product infections, symptoms include fever, swelling in area of bug bite, can cause chronic inflammation of heart and brain, diagnose by blood smear, serology.

Plasmodium

causes malaria, mosquito vector, mother to fetus and blood transfusion transmission, symptoms include chills, fever, sweating, anemia, organ enlargement, 300-500 million cases/year, 2 million deaths/year, diagnose by blood smear, treat with chloroquine, mefloquine

Toxoplasma gondii

reason why pregnant women aren't allowed to change cat litter boxes, also can be acquired by eating raw meats, treatment with pyrimethamine and sulfadiazine; most cases go undetected except for fetuses and AIDS patients.

Cryptosporidium

source is contaminated water, there is often a low-level in water all the time, causes chronic diarrhea in AIDS patients, no effective drugs available

Pinworms

elementary aged children especially get them, can do tape test to detect, may treat based on symptoms - anal itching especially at night, most cases clear up untreated, can treat with pyrantel OTC (over the counter), typically treat whole the household, wash bedding, nightclothes, and hands/nails first thing in the morning

Ascaris, Whipworms, Hookworms

associated with human feces used as fertilizer and defecation into the soil, transmitted through feces, can cause anemia, can hinder development and even be fatal in children, Ascaris is now uncommon in the U.S., but whipworms and hookworms occur in the southern U.S., treatment with mebendazole, etc

Trichinella

source is undercooked pork (or bear meat), causes flulike symptoms, diarrhea, can migrate and form cysts in muscle, heart, and brain - no cure at this point

Taenia

tapeworm genus - infections can cause vague symptoms including abdominal pain and nausea, can be serious if they lodge in heart, eye, or brain.

Variola virus

causes smallpox, eradicated with last case worldwide in1977, highly contagious, high fatality rate (30%), no longer vaccinate for it, though vaccine is still produced and stocked in case of outbreak

Molluscum

primarily an infection of children - spread by contact, causes small, smooth macules on skin, can also be sexually transmitted, can remove macules by freezing, etc., infections in children typically clear up on their own by age 8-10.

Herpesvirus - HSV-1

cold sore/fever blister

Herpesvirus - HSV-2

genital

Varicella-Zoster Virus

Causes chickenpox and shingles.

cause pox sores on skin, shingles lesions occur along peripheral nerve lines, live attenuated vaccines for both, treatment with acyclovir, interferon for systemic disease

Cytomegalovirus

most cases asymptomatic, but affects AIDS and other compromised patients (mono-like disease) and newborns, transmitted through bodily fluids (including breast milk)

Epstein-Barr Virus

causes mononucleosis; 70% of college-age Americans have never had it, but by midlife 90-95% of all people have been exposed to it, causes high fever, sore throat with exudate, swollen lymph nodes in clinical cases

Hepatitis

caused by a virus that infects the liver, causes jaundice (yellowing of the skin)

Hepatitis A

from contaminated food (from infected worker); RNA virus

vaccination available

Hepatitis B

blood, sexual or blood transmission

vaccination available

Hepatitis C

sexual or blood contact; RNA virus

new treatment for Hepatitis C is expensive ($80,000+) but is a cure and is called Harvoni

Papillomaviruses

different strains cause common, seed, plantar, and genital warts (HPV) - vaccination available for some strains of HPV that cause genital warts and cervical cancer.

Parvovirus

causes Fifth Disease, causes fever, rash on cheeks ("slapped face rash"), can be fatal to fetus, puppies, can also cause disease in adult dogs and cats

Influenza

-causes the flu, most cases due to Influenza A strain,

-strains undergo antigenic shift and drift, mutates rapidly, as most RNA viruses do (RNA as a nucleic acid is less stable and mutates at a higher rate than DNA), vaccine is developed each year on a prediction of the strain(s) that will cause epidemic/pandemic infections in the coming year, treatment with Tamiflu if patient seeks treatment within the first 48 hours (not as effective after 48 hrs.).

Hantavirus

-first seen in 1993,

-transmitted by rats infected from fleas - aerosols left behind from feces, causes respiratory disease that can be fatal

Paramyxovirus

-causes: Parainfluenza, Croup, Mumps, Measles, Respiratory Syncytial Virus (RSV).

-RSV is the most prevalent cause of respiratory infection in children under 6 months of age, can be serious and require hospitalization because of life-threatening blocking of airway by mucus created.

Measles and Mumps = "MM" of MMR vaccine.

Rhabdovirus

-causes rabies, reservoirs = skunks, raccoons, dogs,

vaccination available

Coronavirus

causes SARS (Severe Acute Respiratory Syndrome)

Arborvirus

causes viral encephalitis (inflammation and swelling of the brain), transmitted by arthropods

Human Immunodeficiency Virus (HIV)

retrovirus, RNA virus that has to make a DNA copy of itself to be inserted within our own DNA, destroys the immune system if untreated, treated by protease inhibitors and reverse transcriptase inhibitors, destroy human T cells in the immune system, mutates rapidly, so drugs don't always work, drugs are expensive

Rhinovirus

causes the common cold, mutates rapidly

Rotavirus

causes diarrhea in newborns, can be serious if newborn loses too much fluid/electrolytes

Prions

-cause Mad Cow Disease and the human form of the disease = Creutzfeldt-Jakob Disease, neurological effects, ultimately fatal;

made of misformed infectious proteins