As seen through microscopy using a microscope such as monocular compound microscope, the Staphylococcus aureus is a spherical bacterium or coccus. When examined under the microscope like the monocular compound microscope, it appears in pairs, short chains, or bunched, grape-like groups. These organisms are Gram-positive as examined by means of microscopy under a microscope such as monocular compound microscope. Certain strains are capable of generating a highly heat-stable protein toxin that causes disease in humans. Staphylococcal food poisoning also known as staphyloenterotoxicosis or staphyloenterotoxemia is the terminology of the condition initiated by the enterotoxins that certain strains of Staphylococcus aureus generate.

The commencement of symptoms in staphylococcal food poisoning is commonly rapid and in numerous instances acute, depending on the susceptibility of the person to the toxin, the quantity of infected food  and toxin in the food consumed, and the total well-being of the victim. The commonest signs are prostration, retching, nausea, vomiting, and abdominal cramping. Certain persons may not at all times, display all the symptoms connected with the sickness. In more serious cases, muscle cramping, headache, and transitory alterations in blood pressure and pulse rate may happen. Healing generally takes two days. Nevertheless, it is common for complete recovery to take three days and at times longer in serious cases. The infective dose of the microorganism in order to generate symptoms of staphylococcal intoxication is not more than one microgram in infected food as observed through microscopy under a microscope such as monocular compound microscope. Such toxin level is attained when Staphylococcus aureus populations surpass one hundred thousand for every gram.

In the diagnosis of staphylococcal foodborne disease, appropriate interviews with the victims and collecting and studying epidemiologic information are important. Incriminated foods must be gathered and examined for staphylococci by means of microscopy under a microscope such as monocular compound microscope. The existence of comparatively huge numbers of enterotoxigenic staphylococci is good circumstantial proof that the food has toxin. The most decisive test is the linking of a disease with a particular food or in cases where multiple vehicles subsist, the determination of the toxin in the food sample. In instances where the food may have been treated to destroy the staphylococci, as in pasteurization or heating, direct microscopic observation under a microscope such as monocular compound microscope of the food may help in the diagnosis. A number of serological techniques for detecting the enterotoxigenicity of Staphylococcus aureus isolated from foods as well as techniques for the separation and determination of toxins in foods have been formed and utilized successfully to help in the diagnosis of the disease. Phage typing can also be helpful when viable staphylococci can be segregated from the incriminated food, from sufferers, and from alleged carrier like the food handlers.

The foods that are oftentimes incriminated in staphylococcal food poisoning are poultry and egg products, meat and meat products, salads like potato, egg, chicken, tuna and macaroni, bakery goods like cream-filled pastries, chocolate éclairs and cream pies, sandwich fillings, and milk and dairy goods. Foods that need extensive handling during preparation and that are stored at slightly high temperatures after preparation are oftentimes involved in staphylococcal food poisoning. Such can be examined by means of microscopy using a microscope such as monocular compound microscope.

Staphylococci are present in air, sewage, dust, milk, water, and food or on food tools, ecological surfaces, humans and animals. Humans and animals are the main reservoirs. Staphylococci exist in the nasal passages and throats and on the hair and skin of fifty percent or more of healthy people. This prevalence is even higher for those who link with or who come in contact with sick people and hospital environments. Although food handlers are commonly the chief source of food infection in food poisoning epidemics, equipment and surrounding surfaces can also be sources of infection with Staphylococcal aureus. Human intoxication is triggered by swallowing enterotoxins generated in food by certain strains of Staphylococcal aureus, commonly because the food has not been sufficiently kept hot or cold.