Patogénok

Patogénok refer to disease-causing microorganisms. These microscopic entities include bacteria, viruses, fungi, and protozoa that can invade a host organism and cause illness. The ability of a pathogen to cause disease is known as its pathogenicity. Factors influencing pathogenicity include the virulence of the pathogen, the route of infection, and the host's immune status.

Bacteria are single-celled prokaryotic organisms. Some bacteria are beneficial, playing roles in digestion and nutrient cycling, while others are pathogenic, producing toxins or directly damaging host tissues. Examples of bacterial pathogens include *Streptococcus pyogenes*, which causes strep throat, and *Escherichia coli*, some strains of which can cause severe food poisoning.

Viruses are acellular infectious agents that require a host cell to replicate. They are much smaller than bacteria and can cause a wide range of diseases, from the common cold (caused by rhinoviruses) to more severe illnesses like influenza (influenza viruses) and acquired immunodeficiency syndrome (AIDS, caused by the human immunodeficiency virus, HIV).

Fungi are eukaryotic organisms that can exist as yeasts or molds. While many fungi are harmless or even beneficial, some can cause infections, particularly in individuals with weakened immune systems. Examples include *Candida albicans*, a common cause of yeast infections, and *Aspergillus fumigatus*, which can cause lung infections.

Protozoa are single-celled eukaryotic organisms. Many protozoa are free-living, but some are parasitic and cause diseases in humans and animals. *Plasmodium falciparum*, responsible for malaria, and *Giardia lamblia*, causing giardiasis, are well-known protozoan pathogens. Understanding patogénok is crucial for developing effective prevention and treatment strategies for infectious diseases.