BAC PATHO

Pathogenesis

Mechanism development to signs and symptoms of disease.

Pathogen

Microorganism that is capable of causing diseases.

Adherence

Major initial step in the infection process.

Infection

Multiplication of an infectious agent within the body.

Multiplication

Not an infectious process; part of normal microbiota.

Invasion

Process where bacteria, parasites, fungi, and viruses enter host cells or tissues and spread in the body.

Nonpathogen

Microorganism that does not cause disease; could be part of normal flora.

Virulence

Quantitative ability of an infectious agent to cause disease.

Virulent agent

Can infect the host even in small quantities.

Superantigens

Protein toxins that activate the immune system by binding to MHC molecules or T cell receptors.

Microbiota

Microbial flora within the normal healthy individual.

Opportunistic pathogen

Capable of causing diseases only when the host’s resistance is impaired.

Pathogenicity

Ability of an infectious agent to cause disease.

Toxigenicity

Ability of a microorganism to produce toxins that contribute to the development of disease.

Koch’s postulates

Criteria that a microorganism should be found in all cases of the disease and be grown in pure culture.

Pathogenicity Islands (PAIs)

Large groups of genes associated with pathogenicity located on bacterial chromosomes.

Enterotoxin

Causes diarrhea.

Natural transformation

DNA from one organism is taken up by a different organism capable of recognizing and binding it.

Bacterial pathogenicity

Mechanisms on how bacteria transfer virulence factors and exchange genetic information.

Spores

Physical factors of Clostridia and Bacillus anthracis that protect from nucleic acid, UV light, desiccation, and detergents.

E. coli

Part of the normal microbiota but can frequently cause disease, responsible for UTI and Traveler’s Diarrhea.

Streptococcus pneumoniae

Present in the nasopharynx of healthy individuals; can cause bacteremia.

Clostridium botulinum

Causes paralysis by inhibiting human protein synthesis.