Microbiology

Antibiotic Sensitivity Testing

Method to assess antibiotic effectiveness against bacteria by measuring zones of inhibition.

Disk-Diffusion Method

Placing antibiotic disks on bacteria spread on agar to determine susceptibility.

Clear Zones

Areas around antibiotic disks showing bacterial growth inhibition.

Types of Media

Blood Agar - Detects hemolysis; Mannitol Salt Agar (MSA) - Selective for Staphylococcus; MSB Agar - Detects Streptococcus mutans.

Microbial Antagonism

Competition between normal microbiota and harmful bacteria for nutrients and space.

Streptococcus Species

Includes S. pneumoniae, S. pyogenes, and S. mutans with different hemolysis types.

Staphylococcus Species

Differentiated by coagulase test and catalase test; S. aureus and S. epidermidis.

Handwashing Importance

Reduces infections by removing transient bacteria; historical example by Ignaz Semmelweis.

Epidemiology

Study of disease spread and control; terms include pathogen, host, epidemic, pandemic, and endemic.

UV Radiation

Uses UV light to damage bacterial DNA; effects include thymine dimers and repair mechanisms.

DRT Value

Value used to determine the effectiveness of an antiseptic or disinfectant against specific bacteria.

Antibiosis

Inhibition of one microorganism by another.

Antibiotic

Substance produced by microbes to kill or inhibit other microbes.

Zone of Inhibition

Clear area around an antibiotic disk on an agar plate.

Kirby-Bauer Test

Standardized disk diffusion method used to determine antibiotic susceptibility.

Hand Scrubbing

Process to remove transient bacteria from the skin.

Epidemiology

Study of disease spread, control, and prevention.

Agglutination Reactions

Clumping of particles due to the interaction between antigens and antibodies.

Normal Microbiota

Permanent residents of the skin or body.

Dental Plaque

Biofilm on teeth formed by bacteria like Streptococcus mutans.