Lecture 9

Question 1

Pathogens that produce disease both inside and outside the GIT

Answer 1

E.coli and Salmonella

Question 2

Pathogens that cause disease only inside GIT

Answer 2

Shigella,Vibrio, Campyobacter, H pylori

Question 3

Pathogens present in GIT but cause disease only outside

Answer 3

Kebsiella group, Pseudomonas, Bacteroids

Question 4

G- rods belong to what family?

Answer 4

enterobacteriacea- primarily in colon of humans and animals as normal flora

Question 5

Do gram - rods rely on oxygen?

Answer 5

all are facultative anaerobes except pseudomonas which is an obligate aerobe

Question 6

What do Gram - rods have on their cell wall?

Answer 6

Endotoxin

Question 7

What does E.coli cause?

Answer 7

Urinary trac infections, travelers diarrhea and neonatal sepsis

Question 8

Where is E.coli normal flora found?

Answer 8

in colon and feces

Question 9

How do Gram - move?

Answer 9

move with single flagellum and plenty of pili

Question 10

Pathogenicity of E.coli

Answer 10

adheres to mucous membranes of jejunum and ilium by pili causes intestinal, systemic and urinary infections- some strains cause watery diarrhea and some cause bloody diarrhea

Question 11

What is the most frequent nasocomial infection?

Answer 11

UTI- due to indwelling catheters

Question 12

What other type of infection can E.coli cause from UTI?

Answer 12

infection of bladder known as cystitis- pyelonephritis can occur if infection goes further up

Question 13

Symptoms of bladder infections

Answer 13

frequent urination along with feeling of need to urinate, nocturne, pain in pubic area, hematuria

Question 14

Symptoms of Urethritis

Answer 14

discomfort, irritation or pain at urethral meatus or burning sensation on urination, pyuria, pyrexia, cloudy and foul urine

Question 15

Symptoms of kidney infection

Answer 15

symptoms from urethritis as well as emesis, back/side pain, abdominal pain, high spiking fever, night sweats and fatigue

Question 16

What E.coli looks like on a lab diagnosis when serious infection

Answer 16

pink colony- ferments lactose

urine examination shows pus cells

Question 17

What is travelers diarrhea due to?

Answer 17

drinking water that has been contaminated by sewage

Question 18

What is neonatal sepsis due to?

Answer 18

presence of E.coli in vagina of pregnant women

Question 19

Treatment for GIT infection

Answer 19

no treatment, self-limiting, supplemental fluid may be necessary

Question 20

Treatment for UTI infection

Answer 20

Oral trimethoprim and sulphamethoxazole/cephalosprin and amino glycoside

Question 21

presence of what organism in drinking water is indicative of sewage contamination?

Answer 21

coliform organism

Question 22

What can be done to remove coliform organisms from water?

Answer 22

chlorination of water

Question 23

gram - rod that causes typhoid fever

Answer 23

Salmonella– only through ingestion

Question 24

How does salmonella move?

Answer 24

has a ton of flagellum

Question 25

typhoidal species

Answer 25

S.Typhi and S.Paratyphi are fever producing

Question 26

non typhoidal species

Answer 26

diarrhea producing- Salm. Typhi murium is most common cause of diarrhea in US

Question 27

Mode of transmission of salmonella

Answer 27

ingestion of food and water contaminated with human or animal waste

Question 28

Is there an animal source of transmission for S. Typhi?

Answer 28

No- only human

Question 29

So typhoid fever is mainly due to...?

Answer 29

water contamination with fecal materials- not animal source

Question 30

Symptoms of typhoid fever

Answer 30

severe fever for 3 to 4 weeks, constipation, leukopenia, delirium, tender abdomen, enlarged spleen, rose spots

Question 31

Complications of typhoid fever

Answer 31

intestinal hemorrhage/perforation, gall bladder infection can result in chronic carrier state- bacteria passed in feces for long time

Question 32

How do you diagnose salmonella in the lab?

Answer 32

organism isolated from stool sample in enterocolitis | + blood cultures in typhoid- color less colonies on plate- non lactose fermenter

Question 33

Treatment for enterocolitis

Answer 33

fluids, electrolytes replacement- no antibiotics

Question 34

Treatment for typhoid

Answer 34

ceftrioxone, cipro, ampicillin

Question 35

What is sometimes advised to abolish chronic carrier state of salmonella?

Answer 35

Cholecystectomy

Question 36

Prevention of salmonella

Answer 36

Public health measures- proper disposal of sewage, chlorination of water, dean hands of those handling food

Question 37

Is there a vaccine for salmonella?

Answer 37

yes but not 100% efficacy

Question 38

What does Shigella cause?

Answer 38

causes bacillary dysentery- entercolitis

Question 39

Can shigella move?

Answer 39

Non-motile: no flagellum --- highly virulent!

Question 40

Path of infection from shigella

Answer 40

transmission by fecal-oral route by finger, flies, food, feces-- no animal reservoir (only humans), water outbreaks, disease exclusively GIT invades mucosa of ilium and colon

Question 41

Where does shigella cause inflammation?

Answer 41

exclusively in the GIT- ulcerations- do not penetrate gut wall or enter blood stream

Question 42

Clinical manifestations of shigella

Answer 42

fever, abdominal cramps, tenesmus (sensation of needing to pass bowels) resolves in 2-3 days (no antibodies or vaccines)

Question 43

Treatment for shigella

Answer 43

fluids and electrolytes in mild cases in sever cases, cipro and bactrim NO VACCINATION

Question 44

Prevention of Shigella

Answer 44

proper disposal of night soils, chlorination, personal hygiene

Question 45

What does vibrio cholera cause?

Answer 45

epidemic diarrhea

Question 46

Transmission of Vibrio Cholera

Answer 46

transmitted by fecal contamination of water and food, primarily human source

Question 47

What does Vibrio Cholera secrete?

Answer 47

enterotoxin which causes massive watery diarrhea without inflammation

Question 48

Clinical symptoms of Vibrio Cholera

Answer 48

large watery diarrhea, no cramps, no fever, no inflammation of gut

Question 49

What does Vibrio Cholera lead to?

Answer 49

rapid dehydration an electrolyte imbalance-- may cause hypovolemic shock, cardiac and renal failure

Question 50

Is the mortality rate high for untreated Vibrio Cholera?

Answer 50

YES- 40%

Question 51

Treatment for Vibrio Cholera

Answer 51

fluid and electrolyte replacement, tetracycline

Question 52

Prevention for Vibrio Cholera

Answer 52

public health measures and vaccination

Question 53

What does H. pylori cause?

Answer 53

gastritis and peptic ulcer

Question 54

natural habitat of H. pylori

Answer 54

stomach

Question 55

What does H.pylori produce?

Answer 55

an enzyme urease which causes large amounts of ammonia which neutralizes acidity and helps organismal growth and damage of mucosa

Question 56

Symptoms of H.pylori infection

Answer 56

recurrent pain in upper abdomen, bleeding in intestinal tract( no bacteremia or dissemination)

Question 57

Lab diagnosis of H. pylori

Answer 57

biopsy of gastric muscoa, urease breath test (radio labeled urea is ingested- if present ammonia will be radioactive and radioactive CO2 will be detected)

Question 58

Treatment for H. pylori

Answer 58

amoxicillin, metronidazole, pepto-bismol

Question 59

What does campylobacter jejuni cause?

Answer 59

enterocolitis in children

Question 60

What is the transmission of campylobacter jejune?

Answer 60

fecal-oral transmission from domestic animals (cattle, dogs, chicken)- puppies are the most common source in US

Question 61

Symptoms of campylobacter jejuni

Answer 61

watery, foul smelling diarrhea, blood in stools, fever, abdominal cramps

Question 62

Medicine for treatment of campylobacter jejnui

Answer 62

erythromycin, cipro, aminogycosides