G+ Coag+ Cat+

8 EXOTOXINS (A, B, C1, C2, C3, D, E, H)

Neuro (Vomit) + Enteric (diarrhoea)

NO adenylate cyclase stim.

Onset ~4 hr lasts ~ 1 day

Nausea, cramps, watery diarrhea, headache

WELL-HANDLED FOOD (Meat, cream pastries..)

Baird-parker plate (bulls-eye)  confirm COAGULASE

G+ rod   in chains    Aerobic or Facultative     spored

ENTERIC TOXIN  ST Neurotoxin

Soil, water, dust--> RICE, PLUSES, "Chinese food Synd"

Blood agar plate

G+    Rod  Anerobe   Fermenter   spore   exotoxin  Penicillin

Soil and gut of man and animals  

BOTULISM - CANNING

Neurotoxin - 8 types (A,B,C1,C2,D,E,F,G)  ABE USA

Toxin A 10-8g to kill !

18-36hr incubate, fatal <24hrs

FATAL TOXEMIA - reportable  confirm blood in stool

Clostridium botulinium

Differential diagnoses

Guillian-Barre - ASCENDING paralysis

MS - DESCENDING paralysis, accented during EXCERCISE

Other food poisonings:  NO CRANIAL NERVE INVOLVEMENT

Chemical and non-microbe food poison- onset in MIN.

INFANT BOTULISM

NOT food poisoning

Infants 2 wks - 6 mo

Spores germinate in GI tract

Vegetative cells release toxin (A,B)

Lethargy, loose head cntl, resp arrest

Tx: Botulism Immune Globulin BIG-IV heptavalent

or large dose of horse C. botulinum antitoxin (adults)

MOST COMMON

1. Short acting: wild mushtooms: muscarine,psilocybin

                          Incubate < 2 hrs, VOMIT, DIARRHEA

2. Long-acting: uncultivated - amantia

                         Incubate 4-8, DIARRHEA, VOMIT,

                         can be fatal

MYCOTOXINS aspergillis, fusarium, penicillium

AFLATOXINS  aspergillis flavus - peanuts - temp/humid

CONTAMINATION:  Tree nuts, peanuts

SX

 Acute necrosis

Cirrhosis

carcinoma (liver)

Marine toxin
dinoflagellates 

large reel fish 

NOT denatured by cooking

extremity paresthesia

hot/cold TEMP REVERSAL

Histadine--> HISTAMINE (scrombotoxin)

Scrombridae fish (tuna, mahi, marlin, bluefin)

BURNING SENSATION IN MOUTH + METAL TASTE

WATERY DIARRHOEA, NAUSEA 3-6HRS

DIZZZINESS, RASH, FACIAL FLUSH

NEUROLOGIC AND PARALYTIC

SHELLFISH POISONING

BIVALVES

BREVETOXINS

(heat stable!)   1-3 hr incubation     24-72h duration

parasthesia, mouth numbness and tingling of mouth & extrem.

GI upset

SAXITOXINS

(heat stable!)   1-3 hr incubation     24-72h duration

parasthesia, mouth numbness and tingling of mouth & extrem.

ATAXIA, can go to RESP PARALYSIS 

Escherichia coli

ETEC

•  
  • TRAVELLER's diarrhea
  • N+V   NO FEVER
  • 2 ENTEROTOXINS
  • LT (adenylate cyclase--> up cAMP     AB toxin
  • ST (guanylate cyclase) --> up cGMP  AB toxin
  • Colonizes villi and releases toxin (2-stage)
  • Tx-->NO ANTIBIOTIX

EPEC

• INFANTILE DIARRHOEA
• 50% mortality in developing countries
  
• Bundle Forming Pilus
  • attach to villi
  • Erode 'em-- reduce absorption--> watery diarrhea
• TX: rehydrate + ANTIBIOTICS (trimethoprim)

Vibrio Cholerae

• Curved G-rod non-spore, MOTILE, Oxidase +
• O and H antigens   O1 and O139
• Ferment sucrose and mannose NOT arabinose
  
• ACID SENSITIVE  (food protects in gut)
• AB toxin (like ETEC)
• RICE WATER STOOL
• TX: rehydrate + tetracycline
• In USA, from TRAVELLERS from infected areas
  

Clostridium perfringens

• 2 different Dzs
  • necrotic enteritis (Pig-Bel Dambrand, type C)
  • Type A foodborne infection 
• MEAT
  
  • Cook--> spores -->cool-->vegitative-->Endotoxin A
• 8-24h incubate, watery Drha, N&V, SEVERE abdom. pain,
  
• Monitor elderly and imm. comp Pts
• Large vegitative cells in Feces
  

Bacillus cereus

1. diarrhoea + abdominal pain 8-16 / 12/24h
2. Meat, VEGETABLEs, sauces, pasta, desserts, dairy
3. LT ENTEROTOXIN  -- incr cAMP
4. two modes!
   1. Food poison < 4 hr ST ENTERIC toxin  Vomit
   2. 8-16h Enterotoxin  Water diarrhea   LT protein
      

Compare

B. cereus

food poison vs. foodborne infections

Food poisoning                             Foodborne infection

> short incubation                             longer incubation

> within 4 hrs                                    8-16 hrs

> Emetic toxin                                  Enterotoxin

> Vomit                                            Watery diarrhoea

   - ST neurotoxin                                -LT protein

ROTAVIRUS

REOvirus  (Respiratory Enteric Orphan)

Wheel shape        Non-envelope    11 segments   dsRNA

 10 human serotypes

6 mo< ASYMPTOMATIC > 5 yrs      

48 hrs / up to 6d     Shed in feces for 10d

Only Cholera has severity + freq. of diarrhea

W & w/o vomit

Vaccines

NORWALK VIRUS

(Norovirus)

• smal, non-enveloped,  +ssRNA
• 50% of non-bacterial gastroenteritis in US
• OLDER kids and ADULTS
• "WINTER VOMIT DISEASE"
• Fecal-oral                  
  
• Small intestine
  
• 24-48    / 24-60h
• RT-PCR required to ID       FOOD HANDLERS
  

Adenoviruses

• Icosohedral dsDNA    12 vertices  PENTONS   
• 2 serotypes 40, 41 (group F)
• RESPIRATORY TRACT     5-15% DIARRHOEA
• 2ND to Rotavirus

ASTROVIRUSES

• diarrhoea in Scotland
• small, non-enveloped   +ssRNA
• 3rd to Rota   Peak in Winter 

Hepatitis A

virus

• icosohedral, non-enveloped, +RNA
• Feal-oral    (fruit pickers)
• endemic in Africa, S. Europe
• F+N+V--> subsides --> jaundice --> 1-3 wks, 3rd degree

Hepatitis E

Virus

Non A Non-B

List the Shigella species in order of virulence

MOST VIRULENT

Group A:  S. dysenteriae

Group B: S. flexneri

Group C: S. boydii

Group D:  S. sonnei

LEAST VIRULENT

SHIGELLA VIRULENCE FACTORS

Endotoxin (O antigen)

Exotoxin:  neurotoxic enterotoxin

NAD glycohydrolase
destroys all NAD in cells --> shuts dn metab --> death

Difference between symptoms

of

S. flexneri vs. S. sonnei

S. flexneri:  Stool mucus and blood

S. sonnei:  watery diarrhea, Vomit

Enteroinvasive E. coli

(EIEC)

• Similar to Shigellosis - less severe - no enterotoxin, no cytotoxin
  
• Infective dose 10 organisms !
  
• INVASION of LARGE INTESTINE
• Kills enterocytes--> WBCs, RBCs and mucosal cells in stool
  

Salmonella species

• Ubiquitous
• 3 types of clinical manifestations
  • Gastroenteritis : S. typhimurium, enteritidis, Newport
  • Septicemia/bacteremia (rare) S. cholerasuls
  • Enteric (Typhoid fever):  S. typhi

Salmonella

Entercolitis

(Gasteroenteritis)

FOOD-BORNE

Localized infection

Excessive fluid secretion from ileum and jejunum

PB, fresh produce, alfalfa sprouts, milk

REPTILES

Enteric Fever

S. typhi

US ONLY see in travellers to Asia, Mexico, India

S. paratyphi B

Motile

G- rod

H2S production

Gas from glucose

Serotyping

Typhoid Fever Dx

1. Travel to infected areas (Mexico, Asia, India)
2. Rose coloured spots on abdomen (2-4d)
3. Examination of blood (anemia, leukopenia, no PMNs)
4. Positive Widal reaction (agglutination of O, H antigens)

Campylobacter spp.

(C. ejuni, doylei, coli, lari, hyointestinalis)

Small curved spiral RODS

G-

Cat+

No spores

Motile (single polar flagella)

Zoonotic:  poultry, sheep, cats, dogs

Microaerophilic:  can't grow aerobic or anerobic

fecal contam of food, water

Campylobacter Sx

1. 3-5d after ingest                           ASSOC W/ GUILLAIN-BARRE
   
2. Vomit                                           ascending paralysis
   
3. Diarrhea (profuse (green?)
4. Ab pain
5. Prosration
6. Pyrexia
7. Bloodstained feces
8. ERYC Tx

Yersinia enterocolytica

YERSINOSIS

Y. pseudotuberculosis

Kids < 7, adults

Acute gastroenteritis

Cooler climates

1-40 deg (psychrotroph)

HEAT STABLE ENTEROTOXIN INCR. cGMP

Yersinia enerocolytica

Sx,Dx, Tx

3-7d / 14-21d

abdominal pain

watery diarrhea

doxycycline or oxytetracycline

ASSOC W/RA (?)  T-cell stimulation ???

Stool, MacConkey - pinpoint colonies/special Yersinia media

Vibrio vulnificus

Diarrhea  and infection of cuts

(SALT WATER ABRASIONS)

SUSHI IN JAPAN:  major

Intense skin lesions and gasteroenteritis

stool, TC BS agar, Sucrose -

Enteroaggregative E. Coli

EAEC

No EAF (Enteric Adherence factor- pilli)

AAF:  Aggregative Adherence Factor- close attach

1. Initial addherance to mucosa
2. Enhanced mucus production--> BIOFILM
3. Cytotoxin?
   

ENTEROHAEMORRHAGIC E. coli

VTEC

STEC

VTEC - VEROTOXIN-producing

do not give abiotix - more toxin released

ETEC - SHIGATOXIN -producing

Life-threatening hemorrhagic colitis/uremic snd

1. Acute renal failure
   
2. Thrombocytopenia
3. Microangiopathic hemolytic anemia
   
4. THROMBOTIC THROMBOCYTOPENIA PUPURA
   

VTEC

Pathogenosis

CYTOTOXIN - VEROTOXIN

2 types, VT1, VT2, SHIGA-like toxin

(rRNA) blocks protein synthesis and kills cell

A subunit --> renal epithelium via circulation

do NOT give antibiotics- kills 'em --> release more toxin

Dx

E. coli

MacConkey Agar results

RED (lactose fermenters)

   E.coli   Klebsiella   Emterobacter

NOT RED (neg)

Oxidase (-)    Glucose + -->  Proteus, Salmonella, Shigella

Oxidase (+) G+ --> Pseudomonas, campylobacer

Oxidase (+) G- --> vibrio

C. diff

Nosocomial

Antibiotic-associated, esp. CLINDAMYCIN, AMOXICILLIN

2 toxins: 

A: enterotoxin (fluid accum. in bowel, weak)

B: potent - decr. cell protein synth and disrupts microfilaments

Very mild watery diarrhea, hypo-albumin, leukocytosis

need scope to show

discontinue antibiotic

H. pylori

G-

no spore

Curve

motile - polar 5-6 flagella

Microaerophilic  2-5% O2, 5-10% CO2

Cat+

Urease+  (lets live in low pH!)

coccoidal under culture

Diseases

of

H. pylori

Gastriis

Duodenal ulcers

Gastric ulcer

Gastric cancer

H. pylori

Tx

1.  Triple regimen bismuth salt, metronidazole,

tetra or amox

2. Acid supressors (omerprazole) heals ulcer

Amoxicillin

3. Proton pump inhibitor + metronidazole or trinidazole + clarithromicin (macrolide)

Chron's Dz

Regional enteritis

IBD

M. paratuberculosis

(just like chron's but no abdominal pain)

Bovine Johne's Dz

Obligate intracellular, acid fast rod

NOT UNIVERSALLY EFFECIVE ANTIMICROBIAL

ANTIMICROBIAL THERAPY

METRANIDAZOLE- all Bacterioides

Gentamycin/tobramycin/amikacin: useful

Clindamycin:  60% bacterioides spp