Salmonella species• Gram-negative• Rod-shaped• Motile• Non-sporeforming

Sources• Food sources: meats, poultry, eggs, milk and dairy products, fish,

shrimp, spices, yeast, coconut, sauces, freshly prepared salad dressings made with unpasteurized eggs• Cross contamination: A contaminated food or an infected food

handler or animal to other foods or objects in the environment• Contaminated water / untreated sewage

Target population• Weak immune system (very young and the elderly)• Immunocompromised (HIV or chronic illnesses, immunosuppressant

drugs user)

Two types of illness • Nonthyphoidal salmonellosis• Typhoid fever

Non-typhoidal salmonellosis

• Other than S. Typhi and S. Paratyphi A• Mortality: Generally less than 1% • Onset: 6 to 72 hours• Infective dose: As low as one cell• Route of entry: Oral• Symptoms: Nausea, vomiting, abdominal cramps, diarrhea, fever,

headache• Duration: Generally last 4 to 7 days (acute symptoms – 1 to 2 days)

Com

plic

ation

sDehydration and electrolyte

imbalance

Reactive arthritis may follow 3 to 4 weeks after the onset of acute symptoms

Septicaemia

Typhoid fever• S. Typhi and S. Paratyphi A• Mortality: Untreated, as high as 10%• Onset: Generally 1 to 3 weeks, but may be as long as 2 months • Infective dose: Fewer than 1,000 cells• Route of entry: Oral • Symptoms: High fever (39.4 to 40 °C), lethargy, GI symptoms

(abdominal pains and diarrhea or constipation); headache; achiness; LoA; skin rashes ( a flat, rose-coloured spots)• Duration: Generally 2 to 4 weeks

Com

plic

ation

sSepticaemia

Septic arthritis

Chronic infection of gallbladder

Diagnosis• Serological identification of cultural isolates from stool

Antibiotics• Non-typhoidal salmonellosis• T. Ciprofloxacin 500mg BD (750mg BD in severe infection)

• Tyhoid fever• IM/ IV injection/ IV infusion Cefotaxime 1g/12hours (8g daily in 4 divided

doses; up to 12g daily in 3-4 divided doses)

Bacillus cereus• Gram-positive• Facultative anaerobic• Endospore-forming• Large rod

Sources• Diarrheal-type food poisoning: meats, milk, vegetables, and fish• Vomiting-type food poisoning: rice products, starchy foods (potato,

pasta) and cheese products

Target population• All people are believed to be susceptible to B. cereus food poisoning

Two types of illness• Diarrheal type of illness (large-molecular-weight protein)• Emetic type of illness (low-molecular-weight dodecadepsipeptide)

• Mortality: Rare• Infective dose: The number of organism most often associated with a

potential human illness is 10^5 to 10^8 (The pathogenicity arises from preformed toxin)• Duration of symptoms: Usually subside after 24 hours of onset• Route of entry: Consumption of food contaminated with

enterotoxigenic B. cereus or with the emetic toxin

Diarrheal type of illness• Onset: 6 to 15 hours • Symptoms: Watery diarrhea, abdominal cramps, and pain

Emetic type of illness• Onset: 0.5 to 6 hours• Symptoms: Nausea and vomiting

Complications• Severe systemic and pyogenic infections• Gangrene• Septic meningitis• Cellulitis• Panophthalmitis• Lung abscesses• Infant death• Endocarditis

Diagnosis• Isolation of strains of the same serotype from the suspect food and

faeces or vomitus of the patient• Isolation of large numbers of a B. cereus serotype known to cause

foodborne illness from the suspect food and faeces or vomitus of the patient• Isolation of B. cereus from the suspect foods and determination of

their enterotoxigenicity by serological (diarrheal toxin) or biological (diarrheal and emetic) test

Unreported or misdiagnosed outbreaks• B. cereus diarrheal type (Clostridium perfringens) • B. cereus emetic type (Staphylococcus aureus)