bacteria and viruses Flashcards
what type of virus is rotavirus?
segmented, double-stranded RNA genome
-hubbed wheel with spokes
what type of virus in adenovirus?
complex double-stranded DNA
-3rd most common cause of gastroenteritis in infants and kids
what is type of virus is hep B?
double stranded circular DNA
what type of viruis is astrovirus and norwalk?
single-stranded RNA
what is the second most common cuase of viral gastroenteristis in young children?
astrovirus
what is the most common cause of early prosthetic valve endocarditis?
S. epidermidis
what ist he most common cause of late prosthetic valve endocarditis?
staph. aureus, streptococcus, gram neg bacilli, or multiple pathosgents
what is the most common cause of cervicofacial infections undergoing dental work?
Actinomyces israelii
*anaerobe and would not favor an infection site in the blood strem
what is Nocardia asteroides?
an aerobic filamentous bacterium that cuases chronic lobar pneumonia that may metastasize to the brain
*immunocompromised pts
found in soil and aquatic environments
what is a common cause of cutaneous mycoses?
trichophyton rubrum
-tinea corporis, tinea, cruris, tinea pedis
what is the most common bacteria found in a dog/cat bite wound that can cause an abscess?
Pasteurella multocida
what is Bartonella henselae?
very small, gram-negative bacterium that is closely related to the Rickettsia, although it is able to grow on inert media. It is the cause of cat-scratch disease (a local, chronic lymphadenitis most commonly seen in children) and bacillary angiomatosis (seen particularly in AIDS patients). In this latter patient population, the organism causes proliferation of blood and lymphatic vessels, causing a characteristic mulberry lesion in the skin and subcutaneous tissues of the afflicted individual.
what is brucella canis?
a gram negative rod that is a zoonotic agent-normal host is a dog, but it can cause undulation febrile dz w/ malaise, lymphandenopathy, and hepatosplenomegaly
what is toxocara canis?
a common intestinal parasite of dogs- metazoan parasite that causes visceral larve migrans
what is a Yersinia enterocolitica infection?
- acute ileitis and D
- fecal-oral route and infects the terminal ileum
- RLQ tenderness
- can be distinguished from appendicitis will have difficutly moving bowesl
what does campylobacter jejuni present with?
bloody or non bloody D
what does salmonella enteritidis present with?
an acute diarrheal illness w/ diffuse pain
what is cholera?
vibrio cholerae- produces a toxin that activates adnylyl cyclase in intestinal epithemial cells of the small intestine
what does the cholera toin do?
it caues hypersecretion of water and Cl ion=massive D
what causes death by cholear?
hypovolemia
when do epidemis of cholear occur?
times of war, overcrowding and famine, and where sanitation is inadequate
how is cholera spread?
ingestion of contaminated food or water
what are the clinical findings of cholera?
sudden onset of severe, frequent “rice water” D (gray, turbid, w/o odor, blood, or pus); dehydrations, hypotension,, electrolyte imbalance
dx studies of cholear?
stool cultures are postitive for V. cholerae; serum agllutination test
what are the tx of cholera?
replacement of fluids and electrolytes; oral rehydration w/ water containing salt and sugar; severe casese need IV fluids
what abx can be used for cholear?
tetracyclin, ampiclllin, chloramphenicol, bactrim, FQ
how is salmonella transmitted?
via ingestion of contaminated food or water
what are the 3 patterns of salmonella?
1) enteric (typhoid fever)
2) gastroenteritis
3) bacteremia
what is the incubation period for typhoid fever?
5- 14 days
what is the PP of typhoid fever?
organism enter the mucosal epithelium of the intestines and invade adn replicate w/ in the macrophages of peyer’s patches, mesenteric lymphnodes,and spleen