Ch. 13 – Microbiology – Flashcards
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| What is the resident biota? |
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| A large array of microorganisms that favorably inhabit the human body in abundance. |
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| Where are microbes found prominently on the human body? |
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| In locations exposed to the environment such as the skin and digestive tract. |
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| What plays a role in the balance of microbes in your flora? |
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| Competition with other organisms and repeated interaction with the environment |
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| Why do some pathogens that can be harmful outside of your biota not cause infection in your biota? |
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| Competition limits their growth |
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| How does the biota play a role in the body's defense? |
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| By producing antibiotics and inhibiting entry and growth of other pathogens. |
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| Where does initial colonization take place? |
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| In utero. |
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| What is the order of colonization? |
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| 1.)Skin 2.)Respiratory 3.)Digestive |
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| When does the skin become colonized? |
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| As soon as the water breaks, microbes in the vagina can enter the womb. During birth, the baby is exposed to an even larger number of microbes. |
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| When does colonization of the respiratory system happen? |
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| With the baby's first breath. Exposure continues as the baby comes into contact with mother, family and hospital staff. |
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| When does the colonization of the digestive tract occur? |
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| With the baby's first feeding. Microbes vary depending on if breast of bottle fed. |
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| When does stabalization occur? |
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| Following weaning, introduction of solid food and erruption of teeth. |
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| What influences the biota of the skin? |
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| dryness, humidity, occupational exposure, clothing. |
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| Where are very rich biota communities located on the skin? |
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| Regions where the skin joins with mucus membranes. |
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| What are the 2 distinct populations of skin biota? |
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| 1.)Transient 2.)Resident |
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| What is transient biota? |
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| Clings to the surface but does not usually grow there. Acquired during routine exposure to the environment or other people. Drastically influences by hygiene. |
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| What is resident biota? |
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| Inhabits deeper portions of the epidermis and in the glands and follicles. Population is more stable, predictable and less influenced by hygiene. Primarily composed of bacteria such as Staphylococcus. |
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| What are some bacteria found in the flora of your mouth and esophagus? |
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| Streptococcus, Neisseria, Lactobacillus, Haemophillus. |
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| What are some bacteria found in the flora of your stomach? |
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| Helicobacter Pylori is the ONLY KNOWN bacteria that can live in the acidic stomach. |
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| What are some bacteria found in the flora of your large intestine and rectum? |
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| Almost completely anaerobes. Bacterioides, Fusobacterium, Lactobacillus, Clostridium. |
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| What are bacteria in the large intestine and rectum found in smaller amounts? |
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| Coliforms - E.Coli, Enterobacter, Citrobacter. |
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| What are coliforms? |
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| Gram-neg, lactose fermenting, facultative anaerobic bacteria found in the colon. |
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| What contributes to intestinal odor and discomfort that comes along with lactose intolerance? |
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| Coliforms |
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| Where is most bacteria in the respiratory tract primarily seen? |
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| Upper respiratory tract |
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| What bacteria is in the flora of your nasal enterence? |
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| Staphylococcus |
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| What bacteria is in the flora of your nasopharynx? |
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| Neisseria |
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| What bacteria is in the flora of your oropharynx? |
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| Streptococcus |
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| What bacteria is in the flora of your Laryngopharynx and tonsils? |
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| Haemophillus |
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| Why are there little bacteria in the lower respiratory tract? |
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| Conditions are unfavorable for permanent residents. |
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| What is the bacteria found in the flora of your urethra? |
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| Usually sterile but there is nonpathogenic streptococci, staphylcocci, lactobacillus and ocassional coliforms. |
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| What makes women more succeptible to UTI's? |
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| The shorter urethra. |
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| What bacteria is found in the flora of the vagina BEFORE puberty? What is the pH? |
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| Staphylococcui, Streptococci, Candida. pH 7 = basic |
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| What bacteria is found in the flora of the vagina AFTER puberty? What is the pH? |
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| Lactobacilli most prevalent. Candida still present. Estrogen causes the vagina to secrete glycogen. pH lowers to 4.5 = acidic |
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| What bacteria is found in the flora after menopause? |
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| Biota and pH will return to pre-puberty levels. |
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| What is a pathogen? |
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| A microbe whose relationship with its host is parasitic and results in infection and disease. |
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| What does the type and severity of infection depend on? |
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| Pathogenicity of the organism and condition of the host. |
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| What is pathogenicity? |
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| An organism's potential to cause disease. |
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| What is a true pathogen? |
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| Microbes with the ability to cause disease in individuals with noraml immune systems. |
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| What is a Opportunistic pathogen? |
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| Cause disease when the defenses are compromised. |
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| What are virulence factors? |
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| Properties that enable a microbe to invafde and infect a host. |
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| What is virulence? |
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| The ability of a microbe to cause infection that takes the presence or absence of virulence factors into account. The MORE virulence factors, the MORE virulent something is. |
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| What is a portal of entry? |
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| The characteristic route that a microbe takes to enter body tissues is known as the portal of entry. |
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| What is an exogenous agent? |
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| Enters the body from the outside environment. Ex: common cold |
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| What is an endogenous agent? |
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| Already exists in the body. ex:Candidas yeast infection |
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| Many pathogens only cause disease when they enter through a specific portal of entry. T or F? |
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| T |
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| How do most pathogens enter the skin? |
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| Through damaged skin like nicks, abrasions and punctures. |
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| Can some pathogens create their own passageways? How? |
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| Yes. Digestive enzymes or bites. |
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| What part of the skin is very susceptible to infection? |
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| Conjunctiva. |
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| How can pathogens get into the gastrointestinal tract? How do most enter? |
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| They can be ingested through food, drink, medicine etc. Most enter through mucus membranes but ulcers and other damage creates another passageway. |
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| When does the anus become a portal of entry? |
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| When anal sex is practiced |
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| Which portal of entry has the greatest number of pathogens? |
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| Respiratory |
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| How do most enter the respiratory tract? |
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| Mucus membranes of the URT but some can enter the LRT as well. |
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| How big are microbes affecting the respiratory tract? |
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| small. |
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| What uses urogenital portals of entry? |
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| Sexually transmitted diseases and UTIS. |
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| Where do STD's and such enter? |
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| Skin, broken/un, mucosa of penis, external genitalia, vagina, cervix or urethra. |
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| Can microbes pass the placenta? |
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| Yes, only a few. |
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| Can babies be effected with going through the birthing process? |
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| Yes, pink eye, meningitis, a UTI... |
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| What is adhesion? |
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| Process by which microbe gains a more stable position in the body. |
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| How do bacteria adhere themselves? |
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| fimbrae, flagella, pili, slime layers or capsules. |
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| How do viruses adhere themselvess? |
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| Attach to a specific receptor on the cell surface that involves specific viral proteins/spikes |
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| How do protozoa adhere themselves? |
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| Structures of locomotion to burrow into the host cell. |
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| How do worms adhere themselves? |
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| By fastening using suckers, hooks or barbs |
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| What are antiphagocytic factors? |
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| Used by pathogens to avoid phagocytosis |
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| What are leukocidins? |
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| Toxic to white blood cells |
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| What is coagulase? |
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| Causes the formation of clots to inhibit WBC movement |
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| What is extracellular surface layer? |
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| Makes it difficult for phagocyte to engulf them. |
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| Can some bacteria survive even after being phagocytised? |
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| Yes, micobacterium |
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| What are the two ways that virulence factors contribute to tissue damage? |
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| 1.)Extracellular enzymes 2.)Bacterial toxins |
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| How do extracellular enzymes work? |
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| Break down and inflict damage on tissues or dissolve the host's defense barriers. |
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| What are 4 examples of extracellular enzymes? |
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| 1.)mucinase 2.)keritinase 3.)collagenase 4.)hyaluronidase - breaks down glue that holds cells together |
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| How do bacterial toxins work? |
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| Specific chemical product that is poisonous to other organisms. |
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| What is an exotoxin? |
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| Released by living bacterial cells into infected tissues. |
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| What is an endotoxin? |
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| Released when a bacteria is damaged or destroyed. |
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| What is a neurotoxin? |
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| Damage to the nervous tissue. Ex: tetanospasmin and anthra toxin |
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| What is a enterotoxin? |
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| Cause symptoms associated with intestinal disturbances. Ex: cholera and shiga toxina |
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| What is a cytotoxin? |
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| Damage a variety of cells by damaging their membranes or interfering with their metabolism. Ex: streptolysin |
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| What is toxigenicity? |
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| The power to produce toxins |
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| What is toxinoses? |
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| A variety of diseases caused by toxigenicity. |
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| What is toxemias? |
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| Toxinoses in which the toxin is spready by the blood from the site of infection. Ex: tetanus |
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| What is Intoxication? |
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| Toxinoses caused by ingestion of toxins. |
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| Microbes eventually settle in a particular ______ ____ and continue to cause damage at the site. |
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| target organ |
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| What is necrosis? |
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| Accumulated damage lead to cell and tissue death. |
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| What are the 4 patterns of infection? |
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| 1.)localized 2.)systemic 3.)focal 4.)mixed |
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| What is a localized infection? |
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| A sinlge microbe enters the body and remins confined to a specific tissue. Ex: boils, fungal skin infections. |
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| What is a systemic infection? |
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| An infection that spreads to several sites and tissue fluids usually in the blood stream. Ex: viral diseases such as measles, chicken pox, aids, anthrax, typhoid fever, syphilis. Diseases can also travel via nerves such as rabies. Can also travel via cerebrospinal fluid such as meningitis |
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| What is a focal infection? |
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| When an infectous agent breaks free of its local infection and is carried to other tissues. |
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| What is a mixed infection/ |
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| Several microbes establish themselevs simultaneously at the infection site. Dental carries, gangrene, wound infections. |
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| What is a primary infection? |
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| Ex: Chicken pox |
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| What is a secondary infection? |
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| Ex: Skin infection following the chicken pox. |
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| What is an acute infection? |
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| Rapid onset with severe but short-lived symptoms |
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| What is a chronic infection? |
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| Progress and persist over a long period of time. |
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| What is a sign? |
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| Any objective evidence of disease as noted by an observer. CAN BE MEASURED. ex: temperature |
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| What is leukocytosis? |
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| An increase in WBC |
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| What is leukopenia? |
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| A decrease in WBC |
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| What is bacteremia? |
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| Circulation of bacteria in the blood stream |
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| What is septicemia? |
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| An acute illness caused by bacteria or toxin in the blood. |
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| What is viremia? |
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| Circulation of virus in the blood. |
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| What is toxemia? |
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| The agent remains locatlized but its toxins are spread throughout the body. |
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| What is a symptom? |
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| The subjective evidence of a disease as sensed by a patient. |
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| What is a sydrome? |
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| When a disease can be identified or defined by a certain complex of signs and symptoms. |
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| What is asymptomatic/subclinical/inapparent infections? |
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| Infections with no obvious signs or symptoms. HPV. |
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| What is the portal of exit? |
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| Specific route taken by pathogens to leave the host. Usually the same as the portal of entry. |
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| What are the respiratory/salvitory portals? |
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| Mucus, sputum, saliva, nasal drainage, other moist secretions act as media for exit. Also, breathing, coughing, laughing and talking push these pathogens out into the environment |
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| How do skin scales act as a portal of exit? |
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| We shed billions of skin cells each day/ lgst component of household dust. |
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| What uses skin as a portal of exit? |
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| Agents of fungal skin infections, syphilus, herpes simplex and small pox. |
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| What is the fecal exit? |
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| Common exit for intestinal pathogens and helminth worms. |
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| What uses the urogenital tract as a portal of exit? |
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| Vaginal discharge/semen. STD's. |
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| What exits in urine? |
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| Not much can stand the high acidity but typhoid fever and tuberculosis. |
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| What is the only natural exit for blood? |
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| Menses. |
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| _____-______ pathogens usually carry pathogens from human blood. |
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| Blood-feeding |
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| What can also cause the transmission of blood pathogens? |
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| Shared needles, small abrasions caused by intercourse can spread HIV and hepatitis. |
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| What are reservoirs? |
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| The primary habitat in the natural world from which a pathogen originates. |
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| What is a source? |
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| The individual or object form which an infection is actually acquired. |
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| What is a human reservoir? |
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| Most significant source of the majority of communicable human diseases. |
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| What are obvious sources of disease? |
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| People with symptomatic infections. |
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| What is a carrier? |
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| Any person who inconspiculously shelters a pathogen that can be spread to others. |
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| What are asymptomatic carriers? |
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| No symptoms at THAT moment while they are contagious. |
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| What are incubation carriers? |
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| Peopel who have infection but do not show symptoms |
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| What are convalescent carriers? |
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| People who are over the symptoms |
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| What are chronic carriers? |
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| Never show the symptoms during this time. |
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| What are passive carriers? |
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| On their person (nurse's shoes. |
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| Which diseases are the easiest to control? |
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| The ones confined to human reservoir. |
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| What is a vector? |
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| a live animal that transmits an infectious agent from one host to another. |
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| What is a mechanical vector? |
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| Organism carries the microbe on their body from one place to another. |
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| What is a biological vector? |
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| Often required for part of the parasite's life cycle; carries the microbe in its body. |
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| What is zoonosis? |
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| An infection indigenous to animals but natrually transmissible to humans. known 150 zoonoses worldwide. |
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| Diseases that can be spread via animals are probably impossible to eliminate. T or F? |
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| T |
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| What are nonliving reservoirs? |
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| Soil/Water. Pathogens with environmental reservoirs are the HARDEST to eliminate. |
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| What is soil an reservoir for? |
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| Anthrax and tetanus |
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| What is water a reservoir for? |
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| Legionnaries disease and Pseudomonas |
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| what is a communicable disease? |
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| When an infected host can transmit the infectious agent to another host and establish infection in that host. |
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| What is a contagious agent? |
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| highly communicable. |
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| What is a noncommunicable disease? |
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| Does not arise through transmission of the infectious agent from host to host. Comes from soil/water. |
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| What is a Horizontal Transmission? |
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| transfer from one person to another through contact, ingestion of food or water or via a living agent such as an insect. OCCURS AFTER BIRTH. |
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| What is a Vertical Transmission? |
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| Transfer from a pregnant woman to the fetus or from a mother to her infant during childbirth. |
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| What are the 3 ways contact transmission can be achieved? |
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| 1.)Direct 2.)Indirect 3.)Droplet |
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| What is direct transmission? |
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| Person to person. Touching kissing sexual intercourse |
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| What is indirect transmission? |
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| Transfer of a pathogen via vehicle. Sharing a drink. |
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| What is a vehicle? |
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| Any inanimate object commonly used by humans that can transmit infectious agents. |
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| What is droplet transmission? |
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| Respiratory droplets can spread disease if persons are in close proximity. |
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| Where can food-borne pathogens originate from? |
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| Animal reservoirs or contamination during food prep. |
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| What reduces fecal-oral contamination? |
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| Hand washing |
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| What is cross-contamination? |
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| Bacteria from one food product is transferred to another food product then injested. |
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| Where do waterborne pathogens usually originate from? |
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| Sewer contamination. |
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| What reduces the risk of waterborne pathogens? |
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| Chlorination and filtration |
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| What is an airborne particle? |
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| Small fluid droplets dry, leaving 1 or 2 organisms attached to a thing coat of the dried material. |
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| Are dead skin cells, household dust and soil disturbed by wind considered airborne particles? |
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| Yes |
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| What is a way to control airborne pathogens? |
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| Filtration |
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| What is a nosocomial infection? |
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| Infections aquired by patients during their hospital stay. |
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| What conditions in the hospital make it easier for diseases to be contracted? |
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| 1.)high density population with many reservoirs/carriers 2.)patients tend to be immunosuppressed 3.)antibiotic-resistant microbes are more prevalent 4.)large number of non-living reservoirs |
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| What does enterococcus cause in a hospital setting? |
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| Wound infections, UTIS and blood infections |
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| What does E.coli cause in a hospital setting? |
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| Hospital-aquired pneumonia |
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| What does staphylococcus cause in a hospital setting? |
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| Pneumonia, surgical wound infections, bed sores and septicimia |
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| What is 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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| What is prevalence? |
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| Percentage of the population having a particular disease at a given time. |
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| What is attack rate? |
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| Percentage of exposed individuals who contract the disease. |
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| What is the incidence rate? |
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| Reflects the number of new cases in a specific time period in a given population at risk. comparison of healthy and infected peopel |
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| What is the mortality rate? |
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| The rate of death within a defined population as a result of the disease. |
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| What is a endemic disease? |
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| When a disease exhibits a relative steady frequency over a long period of time in a specific geographic region. |
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| What is a sporadic disease? |
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| One which is reported at irregular intervals in unpredictable locations. |
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| What is an epidemic? |
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| An unusually large number of casese within the population |
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| What do epidemics arise from? |
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| endemic diseases, or sporadic diseases that are not normally found in the population. |
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| What is a pandemic? |
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| when an epidemic spreads world wide. AIDS |
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| What is the dose? |
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| a certain minimum number of pathogenic cells are required in the body to produce enough damage to cause symptoms. |
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| What is the incubation period? |
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| Period of time necessary for an agent to multiply enough times to cause disease. |
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| Which kind of infections can the body generally fight off? |
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| those that require a long incubation period |
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| Symptoms may not occur during the incubation period but the agent itself can still be ______. |
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| spread. |
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| A disease is less likely to spread in a population that is _______ ____ ____. |
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| immune to it. |
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| What are factors of general health? |
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| Malnutrition, overcrowding, fatigue increase... |
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| Which ages are most suceptible? |
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| Very young and very old |
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| How do religious and cultural practices effect health? |
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| Eating certain dishes or breast feeding infants |
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| Natural immunity may vary with genetic background. T or F? |
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| T |
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| What is occupational exposure? |
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| Different professions result in different exposures. |
