Microbiology Chapter 13 Flashcard
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| Define infection, disease, and infectious disease |
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| 1. Infection: pathogenic microorganisms penetrate the host defenses, enter the tissues, replicates 2. Disease- Pathologic state that results when the infection damages or disrupts tissues and organs- 3. Infectious disease: the disruption of a tissue or organ caused by microbes or their products |
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| Know sites of body that harbor biota |
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| On skin or contiguous mucous membranes Upper Respritory Tract Gastrointestinal tract Outer opening of Urethra External genitalia Vagina External Ear Canal and Eye |
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| Sites that are Sterile (do not harbor Biota) |
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| All internal tissues and organs (See list Below) Heart and Circulatory system Liver Kidney and Bladder Lungs Brain and Spinal Cord Muscles Bones Ovaries/tested Glands Sinuses Middle and inner ear Internal eye FLUIDS WITHIN AN ORGAN OR TISSUE Blood Urine in kidneys, ureters, bladder Cerebrospinal fluid Saliva prior to entering oral cavity Semen prior to entering the urethra Amniotic fluid surrounding the embryo and fetus |
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| Define microbial antagonism and endogenous infection |
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| Microbial antagonism-Suppress pathogens so you don’t get sick Endogenous infection-The microbe is already there in your body (Ear infections) |
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| Factors that weaken the immune system |
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| Old age and extreme youth Genetic defects in immunity and acquired defects in immunity (AIDS) Surgery and organ transplant Organic disease: cancer, liver malfunction, diabetes Chemotherapy/immunosuppressive drugs Physical and mental stress Other infections |
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| Define virulence factor |
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| any characteristic or structure of the microbe that contributes to its virulence Virulence- the degree of pathogenicity |
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| Know portals of entry including which one is the most common |
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| • Nicks, abrasions, and punctures • Intact skin is very tough- few microbes can penetrate • Some create their own passageways using digestive enzymes or bites • GI Tract • Pathogens contained in food, drink, and other ingested substances • Adapted to survive digestive enzymes and pH changes • Respiratory Portal- #1 Portal of Entry • Urogenital Portals of Entry • Sexually transmitted diseases (STDs) • Enter skin or mucosa of penis, external genitalia, vagina, cervix, and urethra • Some can penetrate an unbroken surface • Pathogens that Infect During Pregnancy and Birth • Some microbes can cross the placenta (ex. the syphilis spirochete) • Other infections occur perinatally when the child is contaminated by the birth canal |
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| Source of infectious agent |
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| Exogenous- outside the host Endogenous- part of the host |
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| Microbe enters the tissues of the body by a portal of entry |
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| Usually a cutaneous or membranous boundary Normally the same anatomical regions that support normal biota |
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| Know the acronym TORCH and what each letter stands for |
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| TORCH (toxoplasmosis, other diseases, rubella, cytomegalovirus, and herpes simplex) |
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| infectious dose |
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| amount of bacteria required to actually cause an infection |
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| Toxigenicity: |
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| the power to produce toxins |
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| Toxinoses: |
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| a variety of diseases caused by toxigenicity |
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| Toxemias: |
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| toxinoses in which the toxin is spread by the blood from the site of infection (tetanus and diphtheria) |
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| Intoxications |
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| toxinoses caused by ingestion of toxins (botulism) |
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| Be able to recognize what is a sign and what is a symptom and Define Syndrome |
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| Sign: any objective evidence of disease as noted by an observer Symptom: the subjective evidence of disease as sensed by the patient Syndrome: when a disease can be identified or defined by a certain complex of signs and symptoms |
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| Signs |
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| Fever Septicemia Microbes in tissue fluids Chest Sounds Skin eruptions Leukocytosis Lukopena Swollen lymph nodes Abscesses Tachycardia (increased heat rate) Antibodies in serum |
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| Symptoms |
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| Chills Pain, ache, soreness, irritation Malaise Fatigue Chest tightness Itching Headache Nausea Abdominal Cramps Anorexia Sore throat |
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| Difference between septicemia and bacteremia/viremia |
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| Septicemia: general state in which microorganisms are multiplying in the blood and are present in large numbers Bacteremia or viremia: microbes are present in the blood but are not necessarily multiplying |
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| Know portals of exit |
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| Respiratory and Salivary Portals - Coughing, sneezing , talking and laughing Skin Scales Fecal Exit Urogenital Tract Removal of Blood or Bleeding |
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| Know the examples of latent infections |
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| Herpes simplex Herpes zoster Hepatitis B- more of a chronic condition, escalates over time AIDS-infected viral count goes up for about 2 weeks, then viral count goes back down over next few months, viral count gets very low but never 0, after several years the viral count goes back up, this is stage 4 and is actual AIDS Epstein-Barr |
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| Reservoir: |
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| the primary habitat in the natural world from which a pathogen originates |
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| Source: |
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| the individual or object from which an infection is actually acquired |
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| Carrier: AKA (living reservoirs) Asymptomatic carriers Incubation carriers Convalescent carriers Chronic carriers Passive carrier |
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| an individual who inconspicuously shelters a pathogen and spreads it to others without any notice Asymptomatic carriers- no sign or symptoms Incubation carriers - spread infections agent during the incubation period Convalescent carriers- continue to shed viable mircobes and convey infection to others. Chronic carriers - shelters the infectious agent for a long period after recovery because of the latency of the infections agent Passive carrier- someone that carriers infection from one person to another (such as a dentist) NON LIVING RESERVOIRS- soil and water |
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| Vector: |
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| a live animal that transmits an infectious agent from one host to another Majority are arthropods Larger animals can also be vectors |
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| Biological vector: |
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| actively participates in a pathogen’s life cycle |
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| Mechanical vectors: |
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| transport the infectious agent without being infected |
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| Define zoonosis |
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| an infection indigenous to animals but naturally transmissible to humans –Ex. Rabies, we can get the disease but cannot give it to other humans. |
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| Know the difference between communicable and non-communicable disease (ESSAY) |
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| Communicable disease: when an infected host can transmit the infectious agent to another host and establish infection in that host 1. Transmission can be direct or indirect 2. Contagious agent: highly communicable Noncommunicable disease: does not arise through transmission of the infectious agent from host to host 1. Acquired through some other, special circumstance 2. Compromised person invaded by his or her own microbiota Individual has accidental contact with a microbe in a nonliving reservoir |
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| Know how communicable diseases are spread direct vs. indirect (ESSAY) |
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| Patterns of Transmission- - Contact - Direct (kissing, touching) Droplets - talking and spit saliva Vertical- from mother to child during birth Vector- a person carries it from one patient to another - Indirect Vehicles- Formites- person touches door knob - Fecal-oral contamination can also lead to both of these types of transmission (above and below) - Food, water, biological products- Air- Droplet nuclei(inhaled through mouth) and aerosols produced by cars |
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| Vehicle: |
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| any inanimate material commonly used by humans that can transmit infectious agents (food, water, biological products, fomites) |
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| fomites |
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| Contaminated objects (doorknobs, telephones, etc.) |
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| Nosocomial infections: and the #1 form of nosocomial infection |
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| infectious diseases that are acquired or develop during a hospital stay 2-4 million cases a year Urinary Tract Infections is #1 |
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| Define etiological agent and how you would determine what the agent is |
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| • Etiologic agent: the causative agent • Kosh's 4 postulates is how you would determine what the agent is. |
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| Epidemiology: |
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| the study of the frequency and distribution of disease and other health-related factors in defined human populations |
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| Prevalence |
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| the total number of existing cases with respect to the entire population Prevalence = (total number of cases in population / total number of persons in population) x 100 = % |
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| Incidence Rate |
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| the number of new cases over a certain time period Incidence = number of new cases / total number of susceptible persons |
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| Mortality rate: |
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| the total number of deaths in a population due to a certain disease (# of deaths / entire population) |
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| Morbidity rate: |
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| the number of persons afflicted with infectious diseases (# of people infected / total population x 100= %) |
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| Define epidemic, pandemic, sporadic, and endemic occurrence |
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| Endemic -Outbreak is spread within a defined pattern Epidemic- no defined pattern, spread is sporatic, but does have large case numbers Sporadic Occurance- no defined pattern and low case numbers Pandemic- global spread |
