GI Flashcards
Which organism that is Gram positive cocci in clusters, & forms a yellowish beta hemolytic colony that causes food poisoning?
Staphylococcus aureus
Of the organisms that produce GI related illness which ones are gram negative bacilli?
Vibrio cholerae Vibrio parahemolyticus Vibrio vulnificus Campylobacter jejuni Helicobacter pylori Salmonella spp. (S. enteritidis & typhi) Shigella spp. Escherichia coli (ETEC, EHEC, EIEC) Yersinia enterocolitica
Of the gram negative bacilli that ptoduce GI related issues which ones are also “curved”?
Vibrio cholerae Vibrio parahemolyticus Vibrio vulnificus Campylobacter jejuni Helicobacter pylori
Which organisms that produce GI related issuses are Gram positive Bacilli?
Listeria monocytogenes Bacillus cereus Clostridium perfringens Clostridium difficile Clostridium botulinum
Of the Gram positive bacilli that produce GI related ilnesses, which ones are aerobic?
Listeria monocytogenes
Bacillus cereus
Of the gram positive bacilli that produce GI related illnesses and are aerobic, which one is Spore Forming?
Bacillus cereus
Of the the gram positive bacilli that produce GI related illnesses which ones are anaerobic as well as spore forming?
Clostridium perfringens
Clostridium difficile
Clostridium botulinum
Which viruses cause GI related illnesses?
Rotavirus
Norwalk virus (Norovirus)
Sapovirus
Astrovirus
Which viruses are not envoloped?
Norwalk virus (Norovirus)
Sapovirus
Astrovirus
A patient presentes to your clinic w/ N/V/D & states that their symptoms started about 3 hours after eating (cooked or processed meats (HAM) salads, and cream filled deserts). What bacteria is most likely causing these Sx & how long do you expect them to last?
Staphylococcus aureus; the toxin produced by this bacteria is heat labile, no live vrus is actually ingested. Certain strains produce the enterotoxin when left at 28C for 2 to 4 hours
Sx: should last no longer than 24 hrs.
This bacteria causes a disease w/Sx of hyersecretion of water & Cl, reverses the ion transport in the gut casuing altered permeability, & massive diarrhea (16L/day) leadin to “rice water stools” and severe dehydration. What organism, what is it from, and its incubation period?
Vibrio cholerae = disease Cholera (enterocolitis syndrome/gasteroenterits)
from contaminated water; drinking/food prep with/ or bathing in it
bacteria produces cholera toxin, incubates for few hours to 5 days
you are stationed in a costal asian region and a patient presents w/Sx of Gastroenteritis, they stated that they were eating seafood (most likely uncooked or under cooked oysters) which organism is likely the cause and wht is its morphology?
Vibrio parahemolyticus
Gram negative bacilli curved
A Patient presents to your clinic w/Sx of acute gastroenteritis after visiting a warm coastal region and eating uncooked/under cooked seafood (e.g. oyters) what is a likely cause & what is the morphology of this organism?
Vibrio vulnificus
Gram negative bacilli curved
A patient presents w/ulcerations of intestinal mucousa, N/V/D (infrequently bloody), abd pain, (fever is infrequent). This is caused by eating undercooked chicken or contaminated food from un/under cooked chicken & rawmilk (dairy feces), & drinking unchlorinated water, what is morphology & how long is incubation & Sx going to last?
Campylobacter jejuni
Gram negative bacilli thin curved rods
incubation: 2-5 days
Sx duration: 3-6 days
this organism grows in human bile, has a flagella;adhesive molecules;cytolethal destending toxin(DNAse activity) what is the prevalence in North America?
Prevelaence in north america is # 1 or 2
Campylobacter jejuni
This organism causes peptic ulcers which are Chronic inflammatory lesions of gastric mucus layer
Helicobacter pylori
A patient presents w/ Acute gastroenteritis w/ signs &Sx of acute inflammatory reaction in subepithelial membranes; (rarely bloody) diarrhea, vomiting, fever after eating meat products (turkey/chicken) that were not propperly cooked or eggs, dairy products, or food contamination from preparation?
Salmonella spp. (S. enteritidis)
why are large amounts of Slmonella enteritidis needed to be ingested for it to cause illness?
b/c the organism is usually killed in by stomach acid, need large amount of bacteria so that it can pass trhough and some can survive which will produce intestinal issues
This organism present w/Diarrhea, colon lesions, pus and blood in feces, fever; penetrate GI epithelium. it is transmitted by the fecal to oral route (food/water contaminated w/feces). What is the organism name/morphology; disease name,
Shigella spp.
morphology: gram negative bacilli
disease name: Shigellosis/ Bacillary Dysentery
what population makes of 2/3 of the cases of Shigellosis/ Bacillary Dysentery
childeren under 10 y/o
What toxins are present in Shigella spp. and does it have any antibiotic resistence (if so what is it not resistent to)?
toxins: Endotoxin; Exotoxins(shiga toxin/neurotoxin/ enterotoxin)
Widespread resistance to antibiotics except cephalosporins
what is the incubation/progression of Shigella spp.?
Incubation 12-48 hrs;
Disease progression- bacteria attach/penetrate intestinal mucosal cells/start multiplying intracellularly causing cells to die and slough off w/bleeding
What causes Travelers Diarrhea/morphology & signs/Sx?
Enterotoxic E.Coli (ETEC)
Morphology: Gram negative Bacilli
sign/Sx: Cramps, fever, dehydration and mild (ocassionally profusely) watery stools w/o mucus and blood
What does coliform mean?
Rod shaped gram negative non-spore forming and motile or non-motile bacteria which can ferment lactose with the production of acid and gas.
Commonly used indicator of sanitary quality of foods and water.
Found in the aquatic environment, in soil and on vegetation;
they are universally present in large numbers in the feces of warm-blooded animals. Are not normally causes of serious illness,
they are easy to culture, and their presence is used to indicate that other pathogenic organisms of fecal origin may be present.
This organism is a predominent normal flora of intestinal tract; a coliform and produces hypersecretion of water and chlorides into lumen, inhibits absorption of Na+?
Enterotoxic E.Coli (ETEC)
What are the virulence factors of Enterotoxic E.Coli (ETEC)?
Cholera-like enterotoxin: heat-labile and/or heat-stable enterotoxins; carries genes on plasmids
what type of testing does Enterotoxic E.Coli (ETEC) require?
Antimicrobic susceptibility test needed to determine drug resistant strains
This organism causes Severe abdominal pain, watery diarrhea (grossly bloody later), inflammation; NO FEVER; may cause hemolytic uremic syndrome (HUS) - hemorrhage of kidney tissue; necrosis of epithelial cells. what is it/disease name & its morphology?
Escherichia coli
Enterohemorrhagic (EHEC) Hemorrhagic colitis
gram negative bacilli
What is the epidemiology of Enterohemorrhagic (EHEC) Hemorrhagic colitis?
Ingestion of contaminated meat (HAMBURGER) or other food products/ cattle, chickens and other animals carry as fecal flora.
what type of toxins does EHEC have and what tests are needed for treatment?
Shiga Toxin (ST) - shigella-like, STEC (shiga-toxin producing E.Coli) bacteria invace &multiply inside cell
Antimicrobic susceptibility test needed to determine drug resistant strains
This organism causes Sporadic mild gastroenteritis with signs/Sx of bloody diarrhea, vomiting, low fever, invasive and necrotic to intestinal lining. Patient states that they were eating Pork or tofu (could also be from contaminated water). Which organsim is it likely and its morphology?
Yersinia enterocolitica
Gram negative bacilli
Yersinia enterocolitica invades what area, spread to ? & and may be shed in the stool for how long?
Invades Peyer’s patches and disseminates to liver and spleen
May be shed in stool up to 90 days after Sx
Patient presents w/ food poisoning w/ Sx of fever, muscle aches, & GI Sx after consuming cold cuts, & unpasteruized cheese, (from soil, forage, & animals (feces)). what is the organism & morphology?
Listeria monocytogenes
Gram positive bacilli, aerobic, Non Spore Forming
this organism is an intracellular pathogen that can grow in cold temps?
Listeria monocytogenes
what can Listeria monocytogenes progress to?
miscarriage, stillbirth, neonatal infection
this bacteria cause food poisoning with diarrhea 6-24 hours after consumption & emetic 1-6 hours after consumption of primarily rice. What is the bacteria & morphology?
Bacillus cereus
Gram positive bacillus, spore-forming, aerobic
what is the epidemiology & virulence factors of Bacillus cereus
Natural soil or environmental bacteruim comes esp from cooked riced or dried beans
virulence: Spores germinate and produce toxins
this bacteria causes a food poisoning with the characteristics of “gas gangrene”, what is the bacteria & its morphology?
Clostridium perfringens
Gram positive bacilli, Spore Forming, anaerobe
what virulence factors does C. perfringens have?
Enterotoxin, exogenous bacteria/spores
This bacteria causes an antibiotic associated diarrhea, which is an overgrowth of the normal gut flora following antibiotic treatment, or pseudomembranous colitis, which is a severe form that includes the formation of “psudomembrane” of inflammatory cells,fibrin,and necrotic cells. which bacteria causes this and its morphology?
Clostridium difficile
Gram positive bacilli, Spore Forming, anaerobe
This food born illness typically from canned green beans has the characteristics of Double/blurred vision, drooping eyelids, slurred speech, weakened facial and throat muscles, nausea/vomitting. what causes it and its morphology?
Clostridium botulinum = foodborne botulinum
Gram positive bacilli, Spore Forming, anaerobe
Epidemiology of C. diff?
normally a nosocomail infection (but now in the community)
Antibiotics, hospitals/nursing homes. Transmitted person to person via fecal to oral, spores germinate after passing acid of the stomach
What are the virulence factors of C. diff?
Enterotoxin(C-diff toxin A)
cytotoxin (C-diff toxin B)
spores survive routine surface cleaning
exogenous bacteria/spores
what are the virulence factors of C. botulinum?
Bacteria produce neurotoxin that is heat labile
Type A,B,E (food poisoning)
Type E associated w/fish
this is the most common cause of gastroenteritis in which severe epidemic in young infants & children are mainly affected, due to fecal to oral route. What is the cause and morphology?
Rotavirus
RNA virus
this causes N/V/D, cramps, low fever; 18-48h incubation; illness last 12-60hrs and remits spontaneously (major worldwide cause of viral Gastroenteritis). what is the case and morphology?
Norwalk virus (Norovirus)/Sapovirus/Astrovirus
RNA virus, non-enveloped
what is the epidemiology of Norwalk virus/ Viral gastroenteritis?
Transmitted by food, water, vomitus, very difficult to prevent spread, usually older children and adults; schools, camps, cruise ships, etc.
