1. CLINICAL TOXICOLOGY 1- FOODBORNE DISEASES BACTERIAL FOODBORNE DISEASES
PARASITE (TOXOPLASMOSIS)
2- FOOD ADDITIVES
PRESERVATIVES
COLORING AGENTS

2. BACTERIAL FOODBORNE DISEASES
A- Bacteria are by far the most common contaminants with food and cause many different foodborne diseases
Most diarrhea (1/2 to 1/3) caused by foodborne bacteria
Symptoms of foodborne diseases can range from mild to severe
Some people asymptomatic but can transmit the disease
B- Definition of foodborne disease
Eating food that contains a sufficient quantity of either pathogenic microorganism or their toxins to cause symptoms

3. BACTERIAL FOODBORNE DISEASES
Therefore, the presence of bacteria is not important but the number of bacteria ingested.
The dose required to cause illness can vary markedly for different microorganism
For examples:
Salmonella requires 100,000 bacterial cells inorder to produce symptoms
Shigella requires 10 bacterial cells in order to produce illness
Staphyllococcus required 500,000 microorganisms in order to produce illness

4. PATHWAYS OF FOODBORNE INFECTION CAUSED BY MICROORGANISM
1-Ingested pathogenic microorganism then
*The microrganism penetrates the intestinal mucosa and colonize the GIT
- Examples: Shigella, Salmonella, Escherichia coli
2 –Microorganism travels from GIT to other tissues
Then it stay in this tissues for examples:
- Hepatitis A virus goes to the liver
- Trichinella spiralis goes to muscle
3- The toxins are released as the infecting microorganism multiplies or lyses in the intestinal tract
Examples Vibro cholerae, Clostridium perfringens and E. coli

5. THE MOST COMMON FOODBORNE MICROORGANISMS
A- BACTERIAL
1-Salmonellae species
* Salmonellae Typhi
* S. enteritidis
* S. choleraesuis
2- Pathogenic E. coli
3- Clostridium perfringens types A & C
4- Clostridium botuli

6. THE MOST COMMON FOODBORNE MICROORGANISMS
5- Staphyllococcus aureus
6- Shigella species
* Shigella dysentry flexneri bovidii sonnei
7- many other bacterias
B- PARASITES
1- Toxoplasmosis gondii
2- Trichinella spiralis
3- other parasites such as
- tapeworms
- roundworms
- fish tapeworms

7. THE MOST COMMON FOODBORNE MICROORGANISMS
C- Viruses
1- Hepatitis
2- Human rotavirus
3- Norwalk-type viruses

8. SALMONELLAE SPECIES
Salmonellae species are gram negative bacilli belongs to family enterbacteriacea
Salmonellae has three species
- Salmonellae typhi
- Salmonella enteritidis
- Salmonellae choleraesuis
The main reservoir for Salmonellae is
- intestinal tract of animals
- poultry products such as eggs
- meat

9. CHARACTERISTICS OF SALMONELLAE
Salmonellae grows in aerobic & anaerobic conditions
Salmonellae is sensitive to lower PH that explains it requires large number of bacterial cells to induce symptoms
Most strains are heat sensitive but some are heat resistant
Drying or freezing does not kill it
Contaminated food looks & smell normal

10. SOURCES OF SALMONELLAE
Most common sources of salmonellae are EGGS & poultry products
Ice cream made from processed eggs and home made ice cream made with raw eggs
Deli salads, cold roasted meat
Infected food handler also source of salmonellae especially workers in restaurants

11. SOURCES OF SALMONELLAE
Utensils such as cutting boards and cutting utensils used for uncooked meat and poultry may serve to inoculate other foods
Raw milk and its product such as chedder cheese made from raw milk
Contaminated water
Pets especially reptile

12. SYMPTOMS OF SALMONELLOSIS
Usually occur hours after eating and subside in hours
SYMPTOMS
- Diarrhea resolve within 1-5 days
- Cramps
- Nausea and vomiting
- Chills and fever which resolve within two weeks in Typhi species)
- Stool may contains mucous or blood

13. SYMPTOMS OF SALMONELLOSIS
- in severe case: bacteria travel to distant tissues
- causing
* meningitis
* pneumonia
- Typhoid fever symptoms similar to influenza
and causes constipation while Salmonellae enteriditis caused diarrhae

14. TREATMENT OF SALMONELLA
1- Enterocolitis uncomplicated
* not requires therapeutic intervention
2- Enterocolitis complicated
A- Adult:
* Ciprofloxacin 500 mg po for 3-7 days
* Norfloxacin 400 mg q12 hours for 3-7 days
* Azithromycin 1g once, then 500 mg qd for 6 days
B- Children
* Ampicillin mg/kg/24hrs in 4 divided doses for days
* or Trimethoprim-sulfamethoxazole 10mg-50mg/kg/24 hrs in divided doses for days

15. TREATMENT OF SALMONELLA
3- Bacteremia or Localized infections
A- Adult:
* Ciprofloxacin 400 mg i.v. bid or 500 mg po for 14 days or * Ceftriaxone 1-2 g i.v./i.m. qd for 14 days
B- Children
* Ampicillin 200 mg/kg/24hrs in 4 divided doses for days
* or Trimethoprim-sulfamethoxazole 10mg-50mg/kg/24 hrs in divided doses for days

16. TREATMENT OF SALMONELLA
4- Chronic carrier
* Ampicillin 2-4 g/day plus probenecid 1-2 g/day both divided into 4 oral doses for 6 weeks
* or Trimethoprim(40-160mg)-sulfamethoxazole ( mg)/day divided in 2 doses for 6 weeks
* If gallstones present give Ciprofloxacin 500 mg po for 4-6 weeks or *Norfloxacin 400 mg bid for 4 weeks

17. TREATMENT OF SALMONELLA
Anti-diarrhae is contraindicated because:
* it prolongs the illness
* it precipitates perforation of intestine

18. Escherichia coli 1- Characteristics of E. coli
* It is gram negative bacillus belonging to the family Enterobacteriacea
* It is marker for non-sanitary handling of food and equipment
* Most strains are halmless and live in the intestine of healthy human and animal

19. 2- SOURCES OF E. coli GIT of animals Human feces
Dairy product such as cheese
Raw ground meat or under cooked meat
Cutting boards and contaminated equipment

20. Escherichia coli 1- Characteristics of E. coli O157:H7
* E. coli O157:H7 produces powerful toxins leads to bloody diarrhea
* It can induce hemolytic uremic syndrome leading to acute renal failure
* Antibiotic has no value
* Anti-diarrhea such as lopramide should be avoided

21. 3- Long term complication of E. coli O157:H7
* one-third of patient develop HUS
* They require dialysis
* develop high blood pressure
* develop seizure & blindness
* paralysis
* part of the bowel removed

22. Escherichia coli 3- PREVENTION E. coli O157:H7
* Cook all meat well DONE at least reach temperature 160 F
* Use pasteurized milk or any juices
* good hygiene

23. 1- Most cases mild fluid loss
SYMPTOMS OF E. COLI
1- Most cases mild fluid loss
2- Most Enteropathogenic strains ( ETEC) diarrhea
* Resolves within hours without comlications
* But some cases last for 7 days in adult and longer duration in children
3- Vomiting is rarely occur

24. 4- Enteropathogenic strains cause
SYMPTOMS OF E. COLI
4- Enteropathogenic strains cause
* Sudden onset of severe diarrhea
* with or without abdominal cramping
* followed by the development of watery diarrhea
* then bloody diarrhea

25. 5- Enteroinvasive strains
SYMPTOMS OF E. COLI
5- Enteroinvasive strains
penetrate the epithelium and cause:
* fever & chills & headache
* Abdominal cramp
* profuse watery diarrhea
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

26. 6- Colohaemorrhagic strains
SYMPTOMS OF E. COLI
6- Colohaemorrhagic strains
* cause changes in the colon similar to colitis
* Verocytotoxin is responsible for frank bloody diarrhea
* and severe Abdominal cramp
* in severe cases indistinguishable from cholera
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

27. * not require specific treatment
TREATMENT OF E. COLI
1- Most ETEC resolves within hours without complication
* not require specific treatment
* Some cases require oral electrolytes replacement therapy (ORT) * Because no vomiting
* Antibiotic seldom require
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

28. 2- Antibiotics 2- Enteropathogenic strains produce toxins causes:
TREATMENT OF E. COLI
2- Antibiotics
* Sulfamethoxazole double stregth
(bactrim or septrin Forte) bid for 3 days OR
* Ciprofloxacin 500 mg bid for 7 days
*Bismuth subsalicylate (Pepto-Bismol) may
have anti-inflammatory & bactericidal activity
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

29. 2- Enteropathogenic strains produce toxins causes:
TREATMENT OF E. COLI
In case of E. coli O157:H7 antibiotic may precipitate kidney complication
Anti-diarrhea such as loperamide (Imodium) SHOULD BE ALSO AVOIDED
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

30. SHIGELLOSIS (Bacillary dysentry)
1- Characteristics
It is self limited to intestinal infection
Incubation period from 1-7 days (average 4 days)
It invades colons and end of ileum
It causes extensive inflammatory changes
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

31. SHIGELLOSIS (Bacillary dysentry)
* Four species are caused this disease as follows:
- Dysentriae type-1
This is responsiblefor most severe type
- Flexneri
- bovidii
- sonnei
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

32. SHIGELLOSIS (Bacillary dysentry)
2- SOURCES
* Poor personal hygiene
* poor sanitation
* Majority of caused by fecal-oral transmission
* food served by worker infected with shigellosis
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

33. SHIGELLOSIS (Bacillary dysentry)
3- SYMPTOMS
* Malause
* Fever especially in children rises to C
* Hyperactive bowel sound
* Abdominal tenderness
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

34. SHIGELLOSIS (Bacillary dysentry)
* frequent (multiple per day) small volume watery diarrhea
* followed by dysentry (blood stool) within few days
* painful straining often leads to rectal prolapsed
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

35. SHIGELLOSIS (Bacillary dysentry)
*Small volume stool which greenish in color
* Often contains mucous and /or blood
* Severe case of shigellosis can progress to toxic dilation and colon perforation
* this perforation may lead death
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

36. SHIGELLOSIS (Bacillary dysentry)
* Hemolytic uremic syndrome (HUS)
* HUS is a result of Shigatoxins causes
* Endothelial damage of lamina propria
* Resulting in microangiopathic changes
* renal failure as result of HUS
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

37. SHIGELLOSIS (Bacillary dysentry)
* flexneri infection can progress to Reiter’s syndrome
* Which can last for months or years
* Can leads to chronic arthritis manifested:
- Painful joint
- irritated eyes
- Painful urination
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

38. TREATMENT SHIGELLOSIS
* Rarely requires electrolytes and fliud replacement therapy
* Anti-peristalsis is contraindicated
* which worsening the course of shigella
* it prolongs fever , dysentry and possibly resulting to Toxic megacolon
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

39. TREATMENT SHIGELLOSIS
ANTIBIOTIC IS IMPORTANT IN THE TREATMENT
Ciprofloxacin is highly effective
But not recommended under 17 years old
because of cartilage toxicity
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

40. TREATMENT SHIGELLOSIS
Avoid ampicillin
may precipitate HUS & renal failure
Resistant developed also against
Co-trimoxazole
& nalidixic acid
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

41. TREATMENT SHIGELLOSIS
Administered glucose
to reverse hypoglycemia
Patient requires prolong protein supplement
because the illness causes protein loss
2- Enteropathogenic strains produce toxins causes:
* severe diarrhea
* with profound dehydration & shock
* Without fever

42. SUMMARY OF TRAVELLERS DIARRHEA
1- MOST COMMON CAUSES
A- Enterotoxogenic E. coli
* Self limited illness lasting for several days
2- LESS COMMON
* Shegilla , Entamoeba histolytica
, Campylobacter, vireses

43. TRAVELLERS DIARRHEA Stage of symptoms A- Acute watery diarrhea
* Entertoxigenic E. coli accounts for the majority ( 40%)of these episodes and last about 4-7 days
* In severe case requires hospitalization
B- Dysentry ( diarrhea with blood)
* mostly caused by
- Shegilla - E. coli O157:H7 - Entamoeba histolytica – Campylobacter
C- Persistentent diarrhea with or without intestinal malabsorption

44. PROPHYLAXIS AGAINST TRAVELLERS DIARRHEA
1- Generally do not prescribe drugs prophylactically
2- but instruct the person to begin treatment when symptoms appear
3- However , Ciprofloxacin 500 mg once daily or levofloxacin 400 mg once daily is recommended for adult only
4- Bismuth subsalicylate (pepto-Bismol) is less effective

45. TREATMENT TRAVELLERS DIARRHEA
1- Antidiarrhea such as loperamide (Imodium) & other anti-diarrhea
2- Plus single dose of ciprofloxacin (750 mg) or
-Levofloxacin 500 mg or ofloxacin 400 mg
- usually symptoms relief in less than 24 hours

46. TREATMENT TRAVELLERS DIARRHEA
3- If diarrhea is severe or
associated with high fever or bloody stools:
- ciprofloxacin 500 mg BID for three days in adult
- Trimethoprim-sulfamethoxazole ( resistant has been developed in many areas)
4- ORT (oral rehydratio replacement therapy)

47. CLOSTRIDIUM PERFRINGENS
TYPES:
* Type A: It’s symptoms is mild form
* Type C: Severe type It called enteritis necrotican
* Which causes necrotizing enteritis intestinal (small intestine) ulceration
* which leads to perforation in 40%
* and death

48. CLOSTRIDIUM PERFRINGENS Type A
1- CHARACTERISTICS OF TYPE A:
* Induced by ingested cooked meat or poultry that has not been consumed within 2-3 hours
* Spore multiply rapidly and produce a heat labile enterotoxin
* Incubation period 6-12 hours which is important diagnostic clue
*It is Spore forming and the spore stands at high temperature 100 C

49. CLOSTRIDIUM PERFRINGENS Type A
The spore is highly heat resistant and may survive cooking procedure
When spore ingested, it replicates in small intestine and produces its toxin
2- SOURCE:
Meat and its products are good media to grow
It is common from food serve in institution
Condition of low oxygen favour the growth of this bacteria such roast meat hold for long time before cooking
Eating cold meat increases chance of infection with this bacteria

50. CLOSTRIDIUM PERFRINGENS Type A
3- PREVENTION
Rapidly refrigerate the meat
Cure meat
Avoid the habit of cooling the food at room temperature the freeze.
Food must enter freezer immediately

51. CLOSTRIDIUM PERFRINGENS Type A
4- SYMPTOMS
The symptoms are mild
Occur often within 8-24 hours of ingestion contaminated food and usually last for one day
Abdominal pain (81%) and watery diarrhea (92%) are common
Fever (24%) and vomiting (9%) are uncommon

52. CLOSTRIDIUM PERFRINGENS Type A
5- TREATMENT
Symptomatic therapy to alleviate cramping causing abdominal pain such as antispasmotic
The illness is self limited and rarely last more than 24 hours
Fluid therapy if there is evidence of electrolytes loss
No value of antibiotic

53. CLOSTRIDIUM PERFRINGENS Type C
1- CHARACTERISTICS
It produces toxins called enteritis necroticans which causes necrotizing enteritis
It causes also intestinal (small intestine) ulceration
Which leads to perforation in 40% of patients
It can lead to death

54. CLOSTRIDIUM PERFRINGENS Type C
2- TREATMENT
Anti-toxin against beta toxin of
Clostridium perfringens type C

55. Staphyllococcus aureus
1- CHARACTERISTICS