GIT Flashcards

Question

What are the 3 AG to serotype Enterbacterales O, H, K H flagellar Ag:

Answer 1

Heat labile- strong agglutination -Protein found on flagella of motile GN

Answer 2

Heat labile, on capsule outside cell wall - may mask O agglutination - Salm typhi has capsular Ag called Vi

Answer 3

Perform genus specific antisera Polyvalent O – somatic antigen – fine agglutination Polyvalent H - flagellar antigen – coarse agglutination Must agglutinate with both O & H antisera Vi AG can mask the O you may need to boil it off

Answer 4

Perform species specific antisera S. sonnei Poly D - do first if ONPG pos or indole neg S. flexneri Poly B

Answer 5

Perform serotype specific antisera ‘O157’ serotype: positive agglutination EC O157 antiserum – doesn’t include H7 (sent to PHL for H7 serotyping)

Answer 6

always note specimen # and antiserum -take from non selective media like TSI or BApp- make a milky mixture -add antisera -rock for 1-2 min =no agglutinaton in saline control = VALID heat suspension at 100 for 30 mins to boil off capsular AG

Answer 7

only on D3 Salmonella = MALDI will always call it Salmonella Enterica Ecoli O157 - start with MALDI if you can do vitek GNI Yersinia is confirmed with MALDI if tubes say possible yersinia Campylobacter - confirm with MALDI AFTER oxidase, catalase and gram Shigella needs to be VITEK ID because MALDI cant diff shigella from ecoli

Answer 8

Salmonella if MALDI ID is S. typhi or S. paratyphi & any Shigella

Answer 9

-look for wet, watery, mucoid gray colonies -oxidase first - if neg STOP -if pos - CAT - POS - GRAM -GULL WING GNB -confirm with MALDI -look for darting motility in BHI broth

Answer 10

Salmonella Shigella E.coli O157 Yersinia report stays prelim and write sent to PHL on bac and front

Answer 11

Only enteric pathogens that have been confirmed by MALDI ID

Answer 12

inflammation of the GIT - tummy and intestines -caused by bacteria, bacterial toxins, virus or parasites -transmitted by water/food or close contact with infected person -travellers Diarrhea>3 loose bowel movements

Answer 13

Make Heat-labile (LT) & or Heat-stable (ST) Enterotoxin that causes watery diarrhea and electrolyte imbalance =non inflammatory , superficial, cell damage Makes cytotoxin/EXOTOXIn = destruction of intestinal cell surface or destroy via invasion = inflammatory Bacteria goes from intestinal wall to lymphatic system to blood organs making potential cyto/enterotoxin- invasive infection/enteric fever Make neurotoxin = the toxin is in live bacteria BEFORE ingestion bacteria can use more than one of these

Answer 14

in SI watery diarrhea no WBC in stool caused by vibrio cholera ETEC

Answer 15

Large or small intestine causes Dysentery youll see WBC & may see blood in stool caused by Shigella Salmonella enterica EAEC, EPEC, EHEC, EIEC

Answer 16

Small intestine causes Enteric fever (Typhoid & Paratyphoid fever) Septicemia youll see WBC Cause Enteric fever Salmonella Typhi Salmonella Paratyphi Can enter bloodstream Yersinia Listeria Campylobacter 5% Salmonella enterica

Answer 17

ENTERICA (most common) and bongori most human infections are caused by Salmonella enterica

Answer 18

Enteric fever (invasive Typhoid and paratyphoid fever) Salmonella Typhi causes typhoid fever Salmonella serotype causes Paratyphoid fever Non typhoidal disease causes inflammatory, cytotoxic gastroenteritis Salmonella Typhimurium

Answer 19

found in humans and animals animals, turtles , weed , pp like fecal to oral , Moderate or Large infective dose causes inflammatory gastroenteritis that starts after ingestion becoming diarrhea -self limiting lasts 1-7 days ABtics may make it last longer -5% chance of becoming invasive

Answer 20

only in humans caused by Salmonella Typhi causes Typhoid fever Salmonella Paratyphi (A, B or C) causes Paratyphoid fever - MILD transmission by dirty water/food contact with infected person -food handler -poor areas instances of typhoid fever is low in Canada

Answer 21

Vi capsular antigen only in Salmonella Typhi -hides surface AG from immune system -attaches to intestinal epithelial cells -produces a cytotoxin and damages DNA preventing protein synthesis -production of inflammatory cytokines -Bacteria Enter lymphatics and bloodstream -can go into liver, spleen, BM and gallbladder Invasive Enteric fever gastroenteritis

Answer 22

in 10-14 days you get a headache or diarrhea with hemorrhage -org gets into blood stream, spleen and liver get infected and enlarged -Rose spots on chest -septicemia, meningitis, osteomyelitis, endocarditis -Gallbladder-asymptomatic carrier or secondary inf of intestine

Answer 23

use BM, stool, bile, urine H2S in TSI but weaker than salmonella -O&H serology (Vi masks the O ) -Maldi will only show salmonella enterica -if you think S thyphi because of wk h2S and O neg = AST -Widal test to detect AG in blood -send out to PHL and report to MOH because its communicable

Answer 24

S. dysenteriae (Grp A) S. flexneri (Grp B) way to remember “boys flex muscles” S. boydii (Grp C) S. sonnei (Grp D) way to remember “dads have sons”

Answer 25

Polyvalent serology - does not specify exact serotypes – will be positive for any serotype that is in that group Monovalent serology will specify exactly which serotype you have We do grouping only and then send to PHL for serotyping

Answer 26

Shigellosis also called Bacillary dysentery transmission No animal resevoir Spread by contaminated food Small infective dose needed for kids

Answer 27

Mild form - watery diarrhea and vomiting because of enterotoxin S. sonnei, S. flexneri, S. bodyii . Dysentery type diarrhea - pus, blood and abdominal pain because cytotoxin Shiga toxin (STX)-causes intestinal cell death & inflammation – due to S. dysenteriae Shigella does not spread from intestines to blood

Answer 28

identifies all Salmonella as Salmonella enterica How would be know we have a subspecies Typhi O & H serology agglutinated so theres no Vi AG -set up VITEK ID to determine the serovar -PHL for full ID

Answer 29

Issues differentiating between E coli and Shigella ids both as E coli -we know we have a shigella with screen tubes and serology + Vitek ID -PHL will do full ID

Answer 30

-ecoli acquires virulence genes -transmitted by eating strain in food or water the type of gastroenteritis depends on the pathotype ETEC: Enterotoxigenic E. coli- NON INFLAMM EAEC: Enteroaggregative E. coli -(INFLAMM AND CYTOTOXIC) - BACTERIA LIKE BRICKS, TRAVELLERS EIEC: Enteroinvasive E. coli INFLAMM EPEC: Enteropathogenic E. coli - INFLAMMATORY EHEC or STEC: Enterohemorrhagic/Shiga toxin E. coli (INFLAMM AND CYTOTOXIC) - HUS DAEC: Diffusely adherent E. coli (????causes diarrhea)

Answer 31

EHEC acquire gene from bacteriophage – codes for production of Shiga toxin (Stx 1 or Stx 2) -shiga like toxin or vero toxin -same function like shiga toxin but genetically different -causes blood diarrhea E. coli O157:H7 most common serotype in North America - reservoir is cattle – small infective dose 5% of people infected with EHEC and toxin can get Hemolytic uremic syndrome caused by shiga toxin 2

Answer 32

5-10 % destruction of intestinal lining lets some EHEC enter Peyer’s patch -macrophages produce Shiga toxin and release it when they die -TOXIN not bacteria get into the blood and goes to kidney -glomerular barrier damaged so RBC and proteins will pass into urine -causes kidney failure

Answer 33

Y. enterocolitica (more common) Y. pseudotuberculosis -found in pigs -can survive refrigeration unknown infective dose -self limiting diarrhea with fever and mild appendicitis - Inflammatory + cytotoxic gastroenteritis -spread to blood & disseminate causing invasive gastroenteritis–mortality 50% -person can shed the toxin in stool even after 3 months of symptoms going away

Answer 34

C. jejuni (most common) & C. coli -transmitted by undercooked poultry since it is NF in birds and unpasteurized milk -Moderate/low infective dose -causes self limiting cytotoxic gastro with diarrhea and fever -Bacteria is caused = INVASIVE gastro, if in sick people its fatal -can cause reactive arthritis (RA) & Guillain- Barre syndrome(GBS) -the bacterial AG mimics nerve cell AG so the host immune attacks them causing paralysis = temporary -

Answer 35

caused by O1 serotype where sewage treatment is not enough -transmitted through contaminated water or food -raw shellfish is a source because it will survive high salt -needs a large infective dose because killed by stomach acid -produce heat labile (LT) enterotoxin that causes rice water diarrhea -NON inflammatory gastro treat with fluid replacement and lytes -only look if dr requests

Answer 36

Aeromonas and P shigg are found in fresh/marine water -trasmitted by contaminated water , raw seafood or shellfish Aero makes LT & ST enterotoxins so there is diarrhea WITHOUT blood or pus Plesio can cause 3 types of gastro - acute water diarrhea, dysentery type with blood/pus or chronic diarrhea both can cause septicemia in immunocomps

Answer 37

curved GNB, comma shaped NLF but plated on TCBS media halophilic - loves 6.5% salt oxidase pos gelatin liquefaction pos

Answer 38

GNB, oxidase positive, Gelatin liquefaction pos & MALDI

Answer 39

GNB, oxidase positive may cross react with Shigella antisera

Answer 40

used to isolate Vibrio spp. Selective high pH over 8 with Na thio and Na citrate to supress NF -Bile salts Differential sucrose + Bromthymol Blue & Thymol Blue as pH indicators. -if it ferments glucose = yellow if not then green -Thiosulphate + ferric citrate for H2S detection V. cholerae = yellow colonies V. parahaemolyticus = green w H2S

Answer 41

-acidic or high salt conditions & refrigeration -transmitted through contaminated food, unwashed food -produces cytotoxins that damage cells to cause diarrhea leads to cytokine release initiating inflammatory -in healthy ppl its self limited -in sick ppl it can spread to blood to cause bacteremia and meningitis -in pregnant women it can cross the placenta and infect the fetus or baby during birth

Answer 42

Strict anaerobe GPB that is NF of GIT -long term ABtic use of fluoroquinolone, cephalosporin, penicillin or clindamycin can cause NF to be weaken allowing C diff to grow -C. diff toxin A & B = diarrhea & ulceration/necrosis of intestinal lining -antibiotic associated diarrhea with pseudomembranous colitis -Reduced stomach acid, long term hospital stay, immunocompromised or elderly are at risk -forms endospores which allows it to be resistant = NOCOSOMIAL INFECTION

Answer 43

only test ppl that meet the criteria Hospitalized, immunocompromised, elderly & on long term antibiotics. -needs special media CCFA -looks like ground glass -just because you have C diff doesnt mean it causes pseudomembranous colitis -must confirm Toxin A or B -detect in stool with Elisa

Answer 44

-human pathogen P/P -tolerant to stomach acid -asypm which leads to stomach or duodenal ulcers -increased risk of MALT lymphoma and gastric carcinoma

Answer 45

Burrows in stomach lining so it can avoid the acid pH -uses pili to stick to cells -produces urease to break down ammonia = alkaline pH which damages stomach cells so they cant make mucous -makes cytotoxin = cell death -inflammtion causes more acid to be released in stomach = alcers if it has the CagA it is carcinogenic

Answer 46

detects AB from blood detect AG from stool Carbon urea breath test which detects labeled CO2 end

Answer 47

-stomach lining biopsy or stomach fluid wash by endoscopy -stain slides -culture onto BA microaerophilic 35C and keep for 5 days before you call it negative -GNB (helical shape), Oxidase & urea positive Stool is NOT cultured – inappropriate specimen

Answer 48

-self limiting -hydration -pepto -AST not done Abtics only in sever cases , typhoid fever or to decrease pathogens Dont use ABtics when you have Non typhoidal Salmonella because it can increase duration of infection and shedding EHEC because itll lead to increased Shiga toxin and HUS

Answer 49

Food associated infections when bacteria multiply in the food enough to cause infection and then the bacteria get eaten and produce toxins inside the body. Symptoms take a long time to appear Food poisoning bacteria in food is eaten but you get sick not because of the bacteria but because of the toxin. Symptoms are quick because the toxin acts on the intestine

Answer 50

-meat and dairy -salty foods like deli meat or ham -from food prep surfaces or on a food handler -creates heat stable enterotoxins and staphylococcal enterotoxin like toxins -some toxins act like superAG = proinflammatory response -some toxin inhibit water and lytes reabsorption to cause diarrhea -symps last for 1-6 and stay for 1-2 days -self limiting

Answer 51

-endospores contaminate undercooked food that is not refrigerated properly -eating leads to two types of sickness Diarrheal form - food associated -associated with high protein food like meat -makes 3 heat labile enterotoxins - to cause diarrhea -have symptoms for a long time appear in >6hrs and gone in 24 Emetic vomiting form - food poisoning -improperly cooked and stored rice -eating heat stable cytotoxin called cereulide made in food – stimulates vagus nerve =vomiting Symptoms happen faster <6 hrs, resolve faster 10hrs

Answer 52

-GP but forms spores -NF in intestines' of humans and animals -Spores can survive in cooked food that is reheating improperly or kept at inappropriate temps -seen in meat stews, soups & gravies. -the eaten spores germinate and make heat labile(LT)enterotoxin that binds to the PM of the intestine epithelial cells , forms pores and causes cell death

Answer 53

ANO2 spore forming GPB- improperly canned food makes a neurotoxin

Answer 54

Food associated botulism -person eats the toxin that colonizes the intestine which then makes the toxin Infant botulism when babies are given honey -flaccid paralysis is lethal to babies Wound botulism -when organism enters the wound and makes the toxin -neurotoxin goes into the blood and blocks acetylcholine to cause paralysis give botulism antitoxin

Answer 55

-found in mammals or birds -many people have AB by age 3 -causes Winter diarrhea’ mostly in infants and young children -fecal oral transmission -targets epithelial cells of small intestine -prevents water absorption, loss of water and ions through watery diarrhea

Answer 56

-most cause of viral gastro outbreaks -p/p transmisson with small bit -from shellfish and water -very contagious in day care centers and cruise ships -replicates in intestinal cells and villi are blunted -SUDDEN vomiting with 12-48 hr incubation -self limiting severe dehydration

Answer 57

diarrhea in infants & children

Answer 58

beaver fever in campers amoebic flagellate -cyst and trophozoite cyst in contaminated water or food

Answer 59

Amoebic protozoa(has cyst & trophozoite) Cyst ingested in contaminated food or water –can spread extra-intestinally

Answer 60

Coccidian protozoan with complex life cycle Oocyst ingested in contaminated water – very serious in AIDs patients