git infection

Question 1

describe GIT infections?

Answer 1

Wide range of microbial pathogens are capable of infecting the GI tract

Ingested pathogen may cause disease confined to the gut or may spread to other parts of the body

Symptoms may occur in relation to infections of the mucosal surface or direct invasion to the gut or the effect of microbial toxin ( indirect )

Question 2

What is the most common outcome of GI infection ?

Answer 2

Diarrhea

its even the most common cause of death in developing countries

Question 3

where does GI infections occur?

Answer 3

its disease of poverty , poor sanitation or poor water supply

Using human /animal waste as ferrilizer to outbbreak

Contained crop/water lead to outbreak

Question 4

what is the mode of transmission of GI infection?

Answer 4

1- Feco - oral route

By eating conta food or water

2- Self inoculation

3- Person to person

Question 5

what is gastroenteritis ?

Answer 5

syndrome of diarrhea and vomiting

Question 6

what diarrhea ?

Answer 6

Frequent watery bowel and movement

also commonly defined as :

3 or more loose stools in 24 hours period

acute is less than 14 days

Chronic = more

Question 7

what is tenesmus ?

Answer 7

sensation of needing to pass stool even though the bowel is empty

or feeling the desire to defecate but unable to

Question 8

what is dysentery?

Answer 8

passage of stools with blood and mucous

Question 9

enterocolitis ?

Answer 9

inflammation of mucosa of small and large intestine

Question 10

what are the gram negative bacteria causing diarrhea ?

Answer 10

E. coli

Salmonella

Shigella

Vibrio

Camp jejuni

Question 11

what are the gram POSITIVE bacteria causing diarrhea ?

Answer 11

Staph aureus

Bacillus cereus

Clost. Perfringens

Clost. Botulinum

Clost. Difficile

Question 12

what are the viruses causing diarrhea ?

Answer 12

Rota virus —> most common in CHILDREN

adenovirus 40, 41

norwalk virus

Calcivirus

norovirus

Astovirus

Question 13

parasities causing ?

Answer 13

Giardia lamblia

Entaemoeba histolytica

Cryptospordium parvum

Helmniths

Question 14

where E. coli most common ?

Answer 14

common cause for GIT infection and UTI in developED countries

Cause Travelers diarrhea

Question 15

where is campylobacter jejuni common in?

Answer 15

Developing countries

Question 16

where are clostridium more common ?

Answer 16

C. Perfiringer —> CAFERTIA BUG

C. Diff –> hospital environment

Question 17

which type of vibrio virus ?

Answer 17

Cholera

Question 18

wheres shigella located?

Answer 18

Intestine

Question 19

what does salmonella invade?

Answer 19

Beyond GI system

Question 20

what are the 4 F causing Gasteroentertiis ?

Answer 20

Food

Fluid

Fly

Fingers

Question 21

what are the clinical manifestation of Git infection?

Answer 21

Gastero-entertisi

Non inflammatory gastroenteritis -> food poisoning

Inflammatory gastroenteritis

Question 22

describe non inflammatroy gastroenteritis ?

Answer 22

Food poisoning

Toxin mediated

Pathogens act directly on small intestine to induce fluid secretion

Marked by presence of profuse WATERY diarrhea WITHOUT pus cells and WITHOUT visible blood or mucous in stool

BUT with Abdominal cramps, dehydration , nausea, vomitting

treatment is usually hydrate

Question 23

describe inflammatory gasteroenteritis ?

Answer 23

Actual inflammation of the gut wall by invasion or cytotoxins

Marked by loos stool WITH pus cells + mucous with or without visible blood in stools , tenesmus , abdominal cramping and fevere

Dehydration is UNSUAL

Question 24

clinical manifestation of bacterial non inflammatory gastroenteritis ?

Answer 24

Profuse water diarrhea

Caused by bacterial producing various toxins –> enterotoxins

Incubation period : Several hours to few days

we dont give antibiotic unless severe case of salmonella

Question 25

what is food poisoning

Answer 25

Ingestion of bacterial toxin in food ( intoxication )

Question 26

describe staphly aureus food pois?

Answer 26

Gram + bacteria Caused by toxins in lab test u will detect toxin NOT THE BACTERIA unlike other staph infections Meat, dairy, ice-cream, custard, coleslaw, etc

Question 27

describe bacillus cereus food pois?

Answer 27

gram + as well 2 forms Emetic --> Vomiting and is linked to heat STABLE toxins often from rice Diarrheal form ---> Diarrhea and is caused by heat LABILE toxins typically from meat with longer incubation period and symptoms so emetic ---> Fried rice ( heat stable ) Diarrheal --> meat ( HEAT LABILE )

Question 28

describe clos. perfringens food pois?

Answer 28

also gram + Cafeteria bug/buffer bug Its in the REHEATED FOOD or left unsafe like buffets/cafeteria Easy to culture , stain ,and observe under microscope ( C. diff is difficult to see ) meat, chicken, pork but mainly reheated food

Question 29

describe Clost . botulinum food pois?

Answer 29

also gram + Love low oxygen ---> canned food Home canned food, pickled goods , honey in newborns

Question 30

describe vibrio cholera?

Answer 30

Gram negative Flagellated curved rod causes cholera : Ingested of contaminated water or food ( commonly SHELLFISH ) Infection of wound after swimming in contaminated Bacteria reaches the intestinal epithelial cells PRODUCING CHOLERA TOXIN Cholera toxin CT -> AB toxin , B binds , A causes damage -> activate cAMP - causes reverse osmosis causing water diarrhea Diarrhea --> rice water stools Rapid onset Can cause severe diarrhea Called rice water --> LOSTS OF MUCUS SPECKS in the diarrhea Massive fluid loss --> dehydration,hypertension, etc Bacteria eventually washes out -> self limiting HIGH MORTALITY in children and developing countries Antibiotics only required for severe cases

Question 31

describe Vibrio species ?

Answer 31

V. Cholera : Disease by CHOLERA TOXIN Infection range from asymptomatic to severe rapidly fata diarrhea Spread by consumption of conta. food or water V. parahemolyticus : Most symptomatic infections are self limited diarrhea Associated with consumption of food contaminated RAW SHELLFISH V. Vulnificus :--> NOT DIARRHEA High mortality associated with primary SEPTICEMIA and wound infection --> PATIENTS WITH IRON OVERLOAD --> most commonly Beta thalassemia pateints INFECTION ASSOCIATED WITH EXPOSURE OF WOUND TO CONTA. SALT WATER OR INGESTION OF IMPROPERLY PREPARED SHELLFISH ( like swimming in conta water )

Question 32

describe E. coli?

Answer 32

gram negative rod Found in bowel movement of people and animal ( most common plora in human ) Most infection are endogenous although strains causing Gastroenteritis generally acquired exogenously Associated with Gastroenteritis, UTIS, Meningitis, sepsis and infection Leading cause of travelers diarrhea, frequent cause of many UTI Travelers diarrhea : Watery self limited diarrhea, vomiting ,cramps, nausea ,etc , for 1-3 days,--> TREATED by fluid replacement ,antibiotics

Question 33

what are the virulence factors of E.coli?

Answer 33

Adherence invasion Toxins

Question 34

what is the mode transmission of E. coli?

Answer 34

Person to person Contai. food or water , undercooked beef ( burger ) , unwashed fruit, animal manure

Question 35

describe Enterotoxigenic E. coli strain ETEC?

Answer 35

Watery diarrhea due to heat labile and heat stable entertoxins Doesnt infect intestinal wall Most common type of travellers diarrhea NO FEVER. NO BLOODY DIARRHEA

Question 36

Describe enterohemorrhagic E.coli strain EHEC?

Answer 36

BLOODY DIARRHEA severe illness from infected meat Produce shiga like toxins ( CYTOTOXIN ) Can lead to hemolytic uremic syndrome HUS , (anemia, thrombocytopenia, acute renal failure) MOST COMMON IS O157:H7 Treatment : Supportive

Question 37

describe Enteroinvasive E.coli EIEC?

Answer 37

bloody diarrhea and fever due to intestinal wall invasion Inflammatory diarrhea Closely related to SHIGELLA

Question 37

Describe Enterpathogenic E. coli EPEC strain EPEC ?

Answer 37

Watery diarrhea WITHOUT TOXINS ( ETEC was with toxins ) Adherence Common in children

Question 38

Describe viral non inflammatory gastroenteritis ?

Answer 38

affects infants and young children causes morbidity and mortality Rapid onset Incubation period 4-48 hours

Question 39

Describe rotavirus ?

Answer 39

Most common cause in children Spread via feco-oral route destroy intestinal epithelium Characterized by severe diarrhea , vomiting , abdominal pain fever Self limited disease Vaccination is reccomended

Question 40

describe inflammatory gastero-enteritis ?

Answer 40

Affects both small and large intestine Inflammatory response Stool volume is small , contain MUCOUS and WHITE cells and BLOOD ( inflammatory ) Patient usually has fever complains of abdominal cramps while trying to defecate --> TENESMUS

Question 41

describe campylobacter JEJuni?

Answer 41

Thin curved MOTILE gram negative Micraeophilic and grow best at 42 C In west common cause enteritis ZOONITC infection : Improperly prepared poultry common source of human infection BLOODY DIARRHEA is the most common manifestation --> especially CHILDREN Most infections self limited but can persist for 1-2 weeks ASSOCIATED WITH GULLAIN BARRE SYNDROME

Question 42

how is campylobacter jejuni spread?

Answer 42

Feco oral spread Infection acquired by ingestion of contai food or water Poultry meat, unpast milk

Question 43

describe C. diff ?

Answer 43

gram positive rods Pseudomembranous colitis or diarrhea happen due to prolonged use of broad spectrum antibiotics

Question 44

describe pseudomembranous colitis ?

Answer 44

Most severe form of C. diff diseae profuse diarrhea and abdominal cramping and fever Whitish plaques ( pseudomembranes ) over intact colonic tissue seen on colonscopy

Question 45

describe antibiotic associated diarrhea?

Answer 45

acute diarrhea generally developing 5-10 days after initiation of antibiotic treatment --> clindamycin, penicillin, cephalosporins, fluroquinolones Maybe brief or self limited or more protracted

Question 46

describe shigella ?

Answer 46

Gram negative NON motile rods NON flagellated Non invasive common among children ( Daycare or nurseries ) Transmitted by 4F ( flies, fingers, food , fluid ) Very virulent ( small amount of it can cause disease ) Duration of disease is 1-2 weeks

Question 47

describe shigellosis ?

Answer 47

gasteroenteritis by shigella Watery diarrhea progressing with 1-2 days to blood diarrhea abdominal cramps, fever, TENESMUS become blood cuz mucosal invaded by bacteria = necrosis and inflammation

Question 48

What causes a severe form of disease ?

Answer 48

S. dysenteriase dysentery caused by the SHIGA TOXIN Dysentery --> bloody mucous small volume + pain during defecate

Question 49

Describe salmonella ?

Answer 49

Gram - rods Flagella MOTILE AND INVASIVE common cause of food associated diarrhea in many devloping countires Diarrhea begin 1-3 days later ASSOCIATED WITH : ENTERITIS, ENTERIC ,FEVER , BACTERMIA

Question 50

How is sallmonella spread?

Answer 50

fecal oral spread contaminated food --> poultry , eggs, dairy products Waterboursne infection is less frequent Person to person TURTLES ( pets )

Question 51

what are the 2 types of salmonella ?

Answer 51

Typhi and paratyphi --> strict human pathogen Localized infection = gastoenteritis Systemic infection : Typhoid and paratyphoid fever ( enteric fever ) can cause bacteremia / septicemia Typhoid fever ---> spots on abdomen

Question 52

management of GI infection?

Answer 52

according to etiology Rehydration is the most important Most bacterial diarrhea require no antibiotic Most viral diarrhea are self limiting Parastic diarrhea needs to be treated with anti parasitic/anti helminth agents Antibiotics are indicated for severe disease with potential complications like salmonella typhi Prevention : Improve sanitaiton, clean drinking water hand washing