Introduction to Bacteriology - ppt download

Examples of Microbes

Microbes / March 5, 2019

This leaflet gives a brief overview of the different types of germs (microbes) that can cause infections and a brief overview of the use of antibiotic medication.

What are microbes?

Healthcare professionals classify 'germs' (microbes) into different groups. The most common groups of microbes that cause illness are described below.


There are many different types of bacteria. Some are helpful and protective to humans. Some flourish naturally in our bodies - particularly in the bowel and vagina - and help to protect the body from infections. However, infections with certain bacteria can cause serious illnesses such as meningitis, pneumonia, tuberculosis, etc. A bacterial infection may be treated with a course of antibiotic medication.


These are smaller and different to bacteria. Many different types exist. Most of the common 'minor' illnesses are caused by viruses. For example, colds, coughs, sore throats, chickenpox and some other rashes. Most common infections in the community are due to a viral infection.

Viral infections are much more common than bacterial and fungal infections.

For many viral infections there are no effective antiviral medicines (unlike antibiotics for bacteria). Fortunately, the immune system in the body usually fights off most viral infections within a few days. Taking 'symptomatic' treatments for a high temperature (fever) or catarrh, such as paracetamol and/or ibuprofen, resting and drinking plenty are usually all that needs to be done to get better.

There are some antiviral medicines that are used for certain infections - such as antiretroviral medicines used to treat HIV. Another example is aciclovir and related medicines which are used to treat certain herpes virus infections. As a rule, antiviral medicines do not clear the virus from the body. They usually work by stopping the virus from multiplying and so 'control' the virus and the infection that it causes.


Many types of fungi exist and cause problems in humans, animals and plants. Fungal infections commonly affect the skin and nails in humans. They can cause ringworm, athlete's foot, other localised skin rashes and infections in and around nails. Modern creams usually work well to clear a local fungal rash quickly. However, nail infections can be rather stubborn and may need long-term treatment of antifungal medicines taken by mouth.

Most fungi are free-living in the environment and few of these are capable of causing infection in an otherwise healthy person. However, they can cause serious infections in patients with weakened immune systems (for example, those who have recently received chemotherapy for cancer).

All you need is here