How do bacteria and viruses differ as pathogens?

Bacteria and viruses differ as pathogens in their structure, reproduction methods, and the diseases they cause.

Bacteria are single-celled organisms that can survive independently, while viruses are smaller and require a host cell to reproduce. Bacteria are prokaryotes, meaning they have no nucleus, but they do have DNA, RNA, and proteins. They can reproduce asexually through binary fission, where one cell divides into two identical cells. Bacteria can cause a variety of diseases, such as tuberculosis, strep throat, and urinary tract infections. They can be treated with antibiotics, which work by disrupting their metabolic processes or cell wall synthesis.

Viruses, on the other hand, are not considered living organisms because they cannot reproduce on their own. They are composed of genetic material (either DNA or RNA) surrounded by a protein coat. Viruses invade host cells and use the host's machinery to replicate. The new viruses then burst out of the host cell, often killing it in the process. Viruses can cause diseases like the flu, HIV/AIDS, and COVID-19. Unlike bacteria, viruses are not affected by antibiotics. Instead, antiviral drugs are used to treat viral infections. These drugs work by inhibiting the replication of the virus.

Furthermore, the immune response to bacteria and viruses is different. The immune system can often recognise and destroy bacteria directly, but viruses, being inside host cells, are harder to target. Vaccines are often used to prevent viral infections by training the immune system to recognise and destroy the virus.

In summary, bacteria and viruses differ significantly as pathogens. Bacteria are independent, single-celled organisms that can be treated with antibiotics, while viruses are smaller, require a host to reproduce, and are treated with antiviral drugs. The immune response to these pathogens also differs due to their unique characteristics.