Upgrade to remove ads
Only $35.99/year

Med Microbio Exam 3 Part 1 (GI dz)

Terms in this set (109)

The ___ have the largest population of microorganism
Intestines
Why are there very few organisms that can survive in the stomach? (no normal flora, just transient organisms)
Acidic environment the HCl creates
The ____ are structures that project from the surface in the GI tract to provide surface area for nutrient absorption
Villi
_____ is a syndrome in which GI symptoms include nausea, vomiting, diarrhea, abd. discomfort
Gastroenteritis
_____ is an inflammatory disorder of the GI tract w/ blood and pus in feces, pain, fever, abd cramps, usually from dz of large intestine
Dysentery
_____ is extreme inflammation of the mucosa of small and large intestine
Enterocolitis
Organisms that cause dysentery are capable of what?
Penetrating intestinal wall and forming ulcers and lesions
_____ is ingestion and growth of bacteria ______ is blood poisoning by ingestion of microbial toxins
Infection, intoxication
____ is the most common upset stomach
Enteritis
What organism is the gram - motile bacilli that causes infantile diarrhea and travelers diarrhea? 6 major pathogenic types
E coli
E colis natural reservoir is where?
Animal intestines
What correlates with the severity of dz caused by e coli?
Enterotoxin produces or if it is enterovasive (invading intestinal epithelium)
What is the incubation and treatment for e coli? Can it be used as a bioteroorism agent?
2-8 days, Rehydration, yes
What are the three main types of e coli?
Entergotoxigenic, enteropathogenic, enterohemorragic
What is the most common cause of hemorrhagic e coli?
O157H&
Which of the three main types of e coli does this describe? Transmitted by contaminated food and water, colonizes small intestine epithelium by fimbriae, 2 enterotoxins (Lt heat sensitive ST heat stable), water diarrhea, travelers diarrhea, dominant in other countries and lasts a few weeks
Enterotoxigenic
Which of the three main types of e coli does this describe?
Occurs in infants often at birth, colonizes small intestine mucosa with bundle forming pili, no toxin, diarrhea
Enteropathogenic
Which of the three main types of e coli does this describe?
Transmitted in contaminated beef or fresh veggies, 1-8 day incubation, low incolum colonizes intestinal epithelium with Bfp, has verotoxin (penetrates cell wall), severe bloody diarrhea ie dysentery, hemolytic colitis, hemolytic uremic syndrome (flagella helps ascend to kidneys)
Enterohemorrhagic
What gram - motile bacilli organism is in the reproductive parts of chicken so they can pass to eggs, is a source in animal and human intestines, can contaminate food and drink?
Salmonella typhimurium, newport, enteritidis
Salmonella has an incubation period of ____ and invades the _______
6-48 hours, small intestine epithelium
What are symptoms of salmonella?
Mild, acute diarrhea w no ulceration or blood, typical gastroenteritis, nausea vomiting cramps
What is the tx for salmonella?
Rehydration, electrolytes, runs course in a few days
How does salmonella work?
Disturbs function of CAMP and uptake of fluids so it causes diarrhea
What salmonella groups cause typhoid fever?
Typhi and paratyphi
What are the 5 Fs that typhoid fever is transmitted?
Fingers, food, flies, feces, fomites
Typhoid incubates 5-21 days and utilizes lymphoid and macrophages to to replicate and spread. What are some standout results of this?
Colonizes small intestine peyers patches, cause ulcers, enters bloodstream
What organism symptoms start as flue like then progress to bloody stools, fever, delerium, and rose spots (bloood hemorrhages under skin)
Typhoid fever
One recovers from typhoid in 4-6 weeks, what is a risk of post recovery?
1-3% become carriers
Treatment for typhoid with abx is sucessful unless?
strain carries R plasmid
Is there a vaccine for typhoid?
Travel vaccine, attentuated, limited affectiveness
Where is campylobacter mostly found?
In the small intestines
______ is a gram -, motile, curved rod thats natural reservoir is birds and animal intestines and is one of the most popular causes of diarrheal disease in the US (often comes from unpasteurized milk)
Campylobacter jejuni
T/F: Campylobacter requires a large inoculum
false, only 500 cells required
What are the prominent clinical signs of campylobacter?
Diarrhea (sometimes bloody), inflammation and ulceration of small and large intestine. Happens 2-7 days after consumption of raw/undercooked poultry
How is campylobacter treated?
No treatment usually, sometimes abx. Recovery happens in one week
What are some rare complications fo campylobacter?
Reactive arthritis, guillian barre sydrome in which antibodies made target nervous system cells causing damage resulting in paralysis for weeks-months
_____ is a gram -, motile curved bacilli that can thrive in warm salty water and thus is transmitted through fecal contaminated warm coastal waters
Cholera/vibrio cholerae
What are prominent clinical signs of cholera?
Dry cold skin, muscle cramps, anuria, thickened blood, shock and coma, RICE WATER STOOL, icterus because of liver shut down
What in cholera causes the severe symptoms?
Colonization of intestinal epithelieum and enterotoxin produced that causes tremendous loss of fluid
Cholera has a 60% mortality, what is the tx? Vaxx avail?
Oral rehydration. Vax previously avail was weakened attenuated and is no longer recommended
What bacteria is causing an ongoing pandemic in asia, africa, and latin america?
Cholera (serogroup 01)
______ is a gram - nonmotile bacilli human pathogen that is the usual cause of bacterial dysentery
Shigellosis
What are the four types of shigella?
S sonnei, S boydii, S flexneri, S dysenteriae
How is shigella transmitted and how much inoculum is required? How long is incubation?
Fecal-oral, low (10-100 cells), 7-24 hours
Shigella species penetrated the intestinal lining and cause what symptoms?
Gastroenteritis, dysentery with blood and mucus in feces (bleeding out possibility), intense abd pain and cramping from invasion of intestinal wall
Why does Shigella dysenteriae cause such severe disease?
It produces the Shiga toxic enterohemorrhagic toxin
What is the tx for shigella? What is risk after recovery?
Abx can be sucessful unless strain has R plasmid (resistance), rehydration. Recovered can be carriers for weeks
What gram + bacilli is an anaerobic spore former that can be present in the intestines but is inhibited by normal flora, and can vegetate if normal flora is wiped out by abx?
Clostridium difficile
What is a problem with c difficile since it is a spore former?
If you get it once you are likely to get it again bc difficult to kill all spores
What are symptoms of c diff?
Enterocolitis, cytotoxin and enterotoxin cause pseudomembrane and tissue necrosis in colon, agressive diarrhea
What strain of c diff is more toxigenic?
C difficile 027
What is the tx for c diff?
Anti-anaerobic therapy, fecal transplant to replace normal flora
What is the 2nd most common form of food poisoning caused by a gram + nomotile coccus?
Staphylococcus aureus
There are several types of staph aureus based on enterotoxin, ___ is the most common
Toxin A
How does staph aureus get transmitted?
Improper food handling, human reservoir, enterotoxin can be released into food and is heat stable
What are symptoms of staph aureus and how long do they last?
Acute onset vomiting within 1-6 hours, recovery within a few hours
____ is a gram + bacilli anaerobic spore former that is found in soil and contaminates as spores on protein rich foods such as meat, poultry, beans
Clostridium perfringens
C perfringens causes illness similar to staph except for what difference?
Incubation is longer, 8-24 hours
What symptoms does C perfringens cause?
gastroenteritis- nausea, diarrhea, vomiting. from enterotoxin
What toxin can be in c perfringens in rare cases that causes acute necrotizing disease- abd pain, bloody diarrhea, intestinal perforations, and 50% mortality?
B toxin
________ is a gram + rice loving bacilli, causes food poisoning with a 8-24 hour incubation period, well known as a spoilage organism found in cereals, rice, meat products, packet soups, and soil
Bacillus cereus
Heat stable entertoxin in bacillus cereus causes _____ and heat labile enterotoxin causes ______
Vomiting, diarrhea
What is the gram + bacilli anaeorobic spore former that causes vision impairment, slurred speech, lethargy, dry mouth, and muscle weakness?
Clostridium botulinum
How does clostridium botulinum cause its affects?
Heat labile neurotoxin released into food, interferes with transmission of nerve impulses resulting in loss of muscle contraction (flaccid/resp paralysis)
What is the tx for botulism? How long does it take?
Large doses of antitoxin (7 types of c botulinum and antibody must be type specific), recovery from symptoms takes weeks to years
What does clostridium botulinum cause in animals?
Fodder disease and limberneck,
What is the most common (72%) form of botulism?
Wound and infant
What causes the 'stomach flu'?
Viral gastroenteritis, intestinal viruses that are transmitted by contaminated food or water/fecal oral
_____ is a GI virus common in infants and young children and ______ is common in adults especially on cruises
Rotavirus, norovirus
Why is it easy for viral gastroenteritis to be passed along on cruises?
Can be hardy and live on surfaces, low inoculum required
What are the symptoms that onset from roto and norovirus after 12-48hrs?
Heavy projectile vomiting, diarrhea, symptoms more severe in infants and can result in dehydration and death
How do viral GI dz cause their symptoms?
Interfering with the nutrient transport across the intestinal membrane
What is the tx for roto and norovirus? Is immunity after recovery? vax?
Fluid replacement, electrolyte replacement. Incomplete immunity. Vaccine available for infants (rotovirus)
What is the only bacteria that can cause disease in the stomach and causes gastric ulcer or peptic disease?
Helicobacter pylori, gram - motile spiral
What are symptoms of helicobacter?
Pain or burning between meals, blood in vomit or bowels from ulcers
How does helicobacter cause its symptoms?
Penetrating mucosal layer of stomach lining and producing acid neutralyzing enzyme urease and cytotoxin. Damages epithelial lining and causes ulcer
What is the issue with ulcers and the immune system in helicobacter?
immune system can contribute to ulcer by causing inflammation
How is helicobacter detected and treated?
Urease can be detected in breath test. Abx
In the ____ form of parasites there is a protective coating on the egg or larvae which you can accidentally reinoculate yourself with
Cyst
______ is a protozoa that causes amoebiasis/amoebic dysentery through fecal oral transmission, fecal contaminated water, anal sex
Entamoeba histolytica
Only 10% of those infected with entamoeba histolytica experience symptoms- what does the mild form involve?
Loose stool, stomach cramp/pain
What does the severe form of entamoeba histolytica involve?
Dysentery, liver abscess, lung and brain invasion, primary amoebic meningoencephalitis causing 95% mortality
How does entamoeba histolytica cause the severe form?
Invading intestinal mucosa and feeding on host tissues and RBCs
How is amoebiasis diagnosed and what is the tx?
Very difficult to diagnose, abx only given if correct diagnosis is made and infection spreads beyond intestines. Some protective immunity
What protozoa causes recreational water illness and has mouths that can attach to intestinal walls?
Giardia lamblia or duodenalis
WHat are the two life cycles of giardia?
Cyst and trophozoite
Giardia is highly contagious- through what routes?
Ingesting infective cysts in contaminated waters, food (rare), and anal sex
What are the symptoms of giardasis?
Diarrhea, flatulence, foul smelling greasy stools that float
What is the treatment for giardia?
Usually self limiting in 2-6 weeks, some meds effective
_____ is a protozoan with a hard outer shell that makes it resistant to chlorine and able to survive for days in the environment, very contagious
Cryptosporidium parvum and hominis
Where is cryptosporidium found?
Contaminated water, food, soil, fresh food irrigated with contaminated water, anal sex
What are symptoms of cryptosporidia?
Repeated invasion of epithelial cells causing profuse water diarrhea, dehydration, wt loss, nauseua. 2-5 weeks cyclic recurrence
What is the tx for cryptosporidia?
In a healthy individual no treatment is needed, in someone with AIDS they may never be cured
____ is the common roundworm that is transmitted through egg contaminated soil and infests the small intestine, larvae hatch in stomach and can escape into blood, lungs, and transfer back to GI tract
Ascaris lumbricoides
What are symptoms of roundworm infection with ascaris lumbricoides?
Abd pain, nausea, cough, difficult breathin, intestinal blockage
How is roundworm infection diagnosed and treated?
Stool sample or passage of worms through stool. Three day course of meds effective
_______ are found in places of poor sanitation, southern US and causes infestation of the large intestine where penetration into the epithelial layer occurs
Trichuris trichuria/whip worms
What are symptoms of trichuris trichuria/whip worms?
Chronic gastroenteritis, nutrient deficiency and growth retardation, rectal prolapse
What kind of parasitic infection can you get from being exposed to egg contaminated soil (ie. being barefoot) that enters the bloodstream, passes through the lungs, before feeding on blood in the intestine?
Hookworms
What are the types of hookworms?
Necator americanus, Ancylostoma duodenale, Strongyloides
What are symptoms of hookworms?
Dermatitis, pneumonitis, protein deficiency, growth/mental retardation, death in infants, severe effects on fetal development
How are hookworms diagnosed and treated?
Eggs in stool, 3 days of meds
_____ causes pinworms which are very common in US children and are acquired by ingesting eggs which results in infestation of the small intesine and large intestine
Enterobius vermiularis
What are symptoms of pinworm infection?
Mild diarrhea, intene anal itching especially at night
What is the treatment for pinworms?
Two doses of meds, family must be treated as a whole to prevent reinfection
What are the organisms that cause tapeworms, typically from eating undercooked meat (pork, beef, fish)
Taenia saginata, Diphyllobothrium latum, Hymenolepis nana
How do tapeworms act in the body?
Attachment by suckers in small intestine, body segments called gravid proglottids contain eggs which are passed in feces. Infest intestine and absorb food and can grow up to 30 feet and live 20 years
What are symptoms of tapeworm infection?
mild diarrhea, vitamin b deficiency. not a ton of clinical signs although severe infection can cause blockage, anemia, occasional appendicitis
What is the treatment for tapeworms?
Medication, can take months to clear infection. Reduces Ige
Other sets by this creator