The microbiology department is where pathogenic microorganisms are detected and identified. The department is divided into three general sections: bacteriology, virology, and mycology. Some large hospitals or reference laboratories may also have a parasitology department.
The microbiology department receives various specimens from the specimen collection and processing department. Such specimens include blood, body fluids, respiratory specimens, skin scrapings, stool, swabs of various kinds, urine, bone, tissue, and more.
A biosafety level is assigned to each laboratory based on the classification of biological agents handled and their associated risks (Table 2). Additional safety training and equipment may be necessary depending on the microbiology department's biosafety level.
Table 2. Biosafety Levels and their Associated Risks and PPE. | Biosafety Level | Agents | Risk of Causing Disease | Protection and Training | Example |
| 1 | Well known | Low | Standard PPE and lab practices | Bacillus subtilis (bacterium) |
| 2 | Well known | Moderate | Limited lab access, disposal precautions, biosafety hoods | Salmonella spp. (bacteria) |
| 3 | Rare | High | Required handling training, biosafety hood work only, specialized PPE | Mycobacterium tuberculosis (bacterium) |
| 4 | Very rare | Very high
(often with no vaccine or treatment options) | Required handling training, specialized engineering features to control air movement, specialized PPE | Ebola
(extremely contagious virus) |
