micro - medical microbiology

What is symbiosis?

The relationship where two organisms live together.

What are the types of symbiosis?

Mutualism (both benefit), Commensalism (one benefits, one unaffected), Parasitism (one benefits, one harmed).

What is microbiota?

Collection of microbes that colonize body surfaces without causing disease.

What is resident microbiota?

Microbes that are a lifelong part of a person’s normal microbiota.

What is transient microbiota?

Temporary residents that are present for hours to months.

What can cause normal microbiota to become pathogenic?

Immunosuppression, changes in normal flora balance, introduction into unusual body sites.

What is contamination?

Presence of microbes on or in the body.

What is infection?

Invasion and colonization of the body by microbes.

What are portals of entry?

Natural body openings (e.g., mouth, nose) or artificial openings used by microbes to enter.

What is the role of adhesion factors?

Specialized structures or proteins used by microbes to stick to host cells.

What is pathogenicity?

Ability of a microbe to cause disease.

What is virulence?

Degree of pathogenicity of a microbe.

What are examples of virulence factors?

Extracellular enzymes, toxins (cytotoxins, neurotoxins, enterotoxins), endotoxins (lipid A), antiphagocytic factors (capsules, lysosome inhibitors).

What are symptoms?

Subjective characteristics of disease felt by the patient.

What are signs?

Objective manifestations of disease that can be observed or measured.

What is a syndrome?

A group of signs and symptoms that characterize a particular disease.

What are the stages of infectious disease?

Incubation, prodromal period, illness, decline, convalescence.

What is the incubation period?

Time between infection and the appearance of signs/symptoms.

What is the prodromal period?

Short period of mild, nonspecific symptoms.

What is the illness period?

Time when disease symptoms are most severe.

What is the decline period?

Period when the body begins to recover as pathogen numbers decline.

What is the convalescence period?

Time when tissues are repaired and the body returns to normal.

What are portals of exit?

Routes by which pathogens leave the host to infect new hosts.

What are reservoirs?

Natural sources of infection like animals, humans, soil, or water.

What is direct transmission?

Disease transmission by direct physical contact between hosts.

What is indirect transmission?

Transmission involving fomites or droplets.

What is horizontal transmission?

Transmission from one person to another.

What is vertical transmission?

Transmission from mother to fetus.

What is a fomite?

Inanimate object that can transmit pathogens.

What is a vehicle?

Non-living carrier like air, water, or food that transmits disease.

What is a vector?

Animal (like an insect) that carries pathogens to a host.

What is epidemiology?

The study of where and when diseases occur and how they are transmitted.

What is incidence?

Number of new cases of a disease in a given time period.

What is prevalence?

Total number of existing (new + old) cases at a given time.

What is mortality rate?

Proportion of deaths in a population due to disease in a time period.

What is endemic disease?

Disease that is constantly present in a population at predictable levels.

What is sporadic disease?

Disease that occurs infrequently and irregularly.

What is an epidemic?

Sudden increase in disease cases in a particular area.

What is a pandemic?

Disease occurring on more than one continent simultaneously.

What are descriptive epidemiological studies?

Collection and analysis of data regarding occurrence of disease.

What are analytical epidemiological studies?

Studies that determine the probable cause, mode of transmission, and means of prevention.

What are experimental epidemiological studies?

Studies that test hypotheses about disease causation and prevention experimentally.

What is a nosocomial infection?

An infection acquired in a health care facility.

What are exogenous infections?

Infections caused by pathogens from the health care environment.

What are endogenous infections?

Infections caused by a patient's own microbiota becoming pathogenic.

What are iatrogenic infections?

Infections that result from medical procedures.

What factors promote nosocomial infections?

Exposure to pathogens, weakened immune systems, transmission between patients and staff.

What microbes commonly cause nosocomial infections?

E. coli, Enterococcus sp., Staphylococcus aureus, Streptococcus sp., Pseudomonas sp.

What are universal precautions?

Procedures to prevent nosocomial infections, including hand washing, glove use, and sterilization.

What are the levels of public health agencies?

Local (county), state, national (CDC, USPHS), and global (WHO).

What are notifiable diseases?

Diseases that must be reported to public health authorities.

What are the jobs of public health agencies?

Data collection, disease prevention, enforcing water and food standards, coordinating disease control campaigns.

Why are airborne diseases difficult to control?

Because air is everywhere and necessary for life.

Why are sexually transmitted diseases difficult to control?

Because of human behavior and the nature of sexual activity.

What roles does human behavior play in disease spread?

Contact with new species, sexual practices, travel, customs, and climate change.