ANTHRACOID BACILLUS

ANTHRACOID BACILLUS

• Some bacilli other than B.anthracis may occasionally cause human infections

• B.cereus – Septicemia, endocarditis, pneumonia, meningitis, wound infections and other suppurative lesions

• B.subtilis, B.licheniformis have also been isolated

• PSEUDOANTHRAX

ANTHRAX BACILLUS

• Non-motile• Capsulated• Grow in long chains• Medusa head

colonies• No growth in

penicillin agar• Haemolysis is absent• Slow liquefaction

ANTHRACOID BACILLUS • Motile• Non capsulated• Grow in short chains• Not present

• Grows usually

• Usually well marked• Rapid liquefaction

• No turbidity in broth• Salicin fermentation

negative• No growth at 45oC• Growth inhibited by

chloral hydrate• Susceptible to

gamma phage• Pathogenic to lab

animals

•Turbidity usual

•Usually positive

•Grows usually•Not inhibited

•Not susceptible

•Not pathogenic

• B.thuringiensis

• B.subtilis

• B.coagulans

• B.steatothermophilus

• B.licheniformis

BACILLUS CEREUS

• Large gram positive bacilli

• Widely distributed in nature

• Generally motile

• Non capsulated

• Large grey irregular anthracoid colonies

• Haemolytic

About….

•M’Fadyean’s reaction negative

•Ferments glucose but not mannitol

•Not susceptible to gamma phage

•Anthrax flouroscent antibody conjugate

•Animal pathogenicity test

• Food poisoning is a common, usually mild, but sometimes deadly illness.

PATHOGENESIS

source : contaminated food

route : ingestion

INGESTION

DIARRHOEAL SYNDROME

EMETIC SYNDROME

• EMETIC TOXIN HBL• DIARRHOEAL TOXIN Nhe Cyt k

B.cereus spores and vegetative cells

Rice pulses Various foods

Spore survives cooking

Organism ingested

Heat labile enterotoxin

DIARRHOEA

Spores survive cooking

Enterotoxin in food not destroyed by heating

Enterotoxin ingested

VOMITING

Diarrhoeal syndrome Emetic syndrome

Infective dose 105–107 (total) 105–108 (cells g−1)

Toxin producedIn the small intestine of the host

Preformed in foods

Type of toxin Protein Cyclic peptideIncubation period 8–16 h 1–5 h

Duration of illness 12–24 h 6–24 h

SymptomsAbdominal pain, watery diarrhoea and occasionally nausea

Nausea, vomiting and malaise

Foods most frequently implicated

Meat products, soups, vegetables, puddings/sauces, milk/milk products

Fried and cooked rice, pasta, pastry and noodles

Lab diagnosis• Specimens : stool sample vomitus food sample

MYPA medium for isolation from feces

TREATMENT

• Short lived and self limiting• Antibiotic not indicated• Gentamycin, vancomycin, ciprofloxocin-bacteremia in immunosuppressed patient

Preventive measures

FOOD POISONINGWHAT???

HOW???

WHEN???

Single source outbreak are becoming larger with modern food processing and

distribution

CAUSES

IMPROPER COOKING

IMPROPER STORAGE TEMPERATURES

TEMP NOT SUFFICIENT TO KILL THE SPORES

FOOD POISONING

INFECTIOUS AGENTS

TOXIC AGENTS

• SYMPTOMS -nausea -vomiting -diarrhoea -fever, chills, -bloody stools, dehydration, nervous

system damage

ETIOLOGY % OF CASES

TYPICAL INCUBATION PERIOD

PRIMARY CLINICAL FEATURES

CHARACTERISTIC FOODS

BACILLUS CEREUS

1-2 1-6 hrs Vomiting, diarrhoea Rice, meat, vegetables

CLOSTRIDIUM BOTULINUM

5-15 12-72hrs Neuromuscular paralysis

Improperly preserved vegetables, meat, fish

STAPHYLOCOCCUS AUREUS

5-25 2-4hrs vomitings Meat, custard salad

CHEMICALS 20-25 1-48hrs variable _

ETIOLOGY % OF CASES

TYPICAL INCUBATION PERIOD

PRIMARY CLINICAL FEATURES

CHARECTERISTIC FOODS

CLOSTIRIDIUM PERFRINGENS

5-15 4-15hrs Watery diarrhoea Meat, poultry

SALMONELLA 10-30 6-48hrs dysentery Meat, poultry, eggs

SHIGELLA 2-5 12-48hrs dysentery variable

VIBRIO PARAHEMOLYTICUS

1-2 10-24hrs Watery diarrhoea Shell fish

LAB

DIAGNOSIS

TREATMENTGENERALLY NOT REQUIRED

REQUIRED WHEN????

PROPHYLAXIS