What is the etiologic agent of an infectious disease?

Infectious diseases can be caused by: Bacteria. These one-cell organisms are responsible for illnesses such as strep throat, urinary tract infections and tuberculosis. Viruses.

How do you identify infectious diseases?

Doctors diagnose infectious diseases using a variety of laboratory tests. Samples of blood, urine, stool, mucus or other body fluids are examined and provide information used in the diagnostic process. In some cases, doctors identify infectious organisms by examining them under a microscope.

What are the methods of identification of microorganisms?

Among the techniques we use are: DNA sequencing – to identify bacteria, moulds and yeasts. Riboprinter analysis – for bacterial identification and characterisation. Repeat–based polymerase chain reaction – for assessing the similarity of microorganisms.

What type of microorganism is the infectious or etiologic agent?

The agents that cause disease fall into five groups: viruses, bacteria, fungi, protozoa, and helminths (worms). Protozoa and worms are usually grouped together as parasites, and are the subject of the discipline of parasitology, whereas viruses, bacteria, and fungi are the subject of microbiology.

What is infectious agent?

Infectious agents are organisms that are capable of producing infection or infectious disease. They include bacteria, fungi, viruses, and parasites.

What are examples of infectious agents?

agents cause a wide variety of diseases affecting various parts of the body. The five main types of infectious agents are bacteria, protozoa, viruses, parasitic worms, and fungi.

What diagnostic test allow microorganism to determine the cause of infectious disease?

Microorganisms have antigens on their surface and inside them. Antigen tests detect the presence of a microorganism directly, so that doctors can diagnose an infection quickly, without waiting for a person to produce antibodies in response to the microorganism.

How do microbiologists identify microorganisms?

Bacteria are identified routinely by morphological and biochemical tests, supplemented as needed by specialized tests such as serotyping and antibiotic inhibition patterns. Newer molecular techniques permit species to be identified by their genetic sequences, sometimes directly from the clinical specimen.

What tools would you need to identify microorganisms that cause disease?

The methods used to diagnose microbial disease include microbial culture, microscopy, biochemical tests, and molecular diagnostics.

What characteristics can be used to describe infectious agents?

Those characteristics are:

• Infectivity: The ability to enter and multiply in the host.
• Pathogenicity: The ability to produce a specific clinical reaction after infection occurs.
• Virulence: The ability to produce a severe pathological reaction.
• Toxicity: The ability to produce a poisonous reaction.

What are the characteristics of infectious agent?

Those characteristics are: Infectivity: The ability to enter and multiply in the host. Pathogenicity: The ability to produce a specific clinical reaction after infection occurs. Virulence: The ability to produce a severe pathological reaction.

What is an agent in microbiology?

The agent is an infectious microorganism, such as a virus or a parasite, that must be present for the disease to occur. These organisms may be passed from person to person, or they can be acquired from the environment through vari- ous modes of transmission. The modes can be direct or indirect.

What are the factors that influence the pathogenicity of an organism?

A variety of factors influence whether exposure to an organism will result in disease, including the organism’s pathogenicity (ability to cause disease) and dose. Over time, the concept of agent has been broadened to include chemical and physical causes of disease or injury.

What determines the specificity of an infectious agent?

Most infectious agents show a significant degree of host specificity, causing disease only in one or a few related species. What determines host specificity for every agent is not known, but the requirement for attachment to a particular cell-surface molecule is one critical factor.

What are the characteristics of a pathogen?

The characteristic features of each pathogen are its mode of transmission, its mechanism of replication, its pathogenesis or the means by which it causes disease, and the response it elicits. We will focus here on the immune responses to these pathogens.