Term
| microorganisms that reside in the body without invasion and can even prevent infections by more pathogenic organisms |
|
Definition
|
|
Term
| What normal flora inhabit the moister areas of the skin (axilla, perineum, toe webs)? |
|
Definition
Staph aureus
Corynebacterium
some Gram-neg bacteria |
|
|
Term
| What normal flora inhabits the drier areas of skin? |
|
Definition
Staph epidermidis (Gram-pos cocci)
Micrococcus sp. (Gram-pos cocci)
Propionobacterium (Corynebacterium) |
|
|
Term
| The skin microbes found in the most superficial layers of the epidermis and the upper parts of the hair follicles are Gram-______ _______ and _______. |
|
Definition
| Gram-pos cocci and corynebacterium |
|
|
Term
| Staphylococci and propionibacteria produce _________ that inhibt the growth of fungi and yeast on the skin. |
|
Definition
|
|
Term
| normal inhabitant of the skin that can become trapped in a hair follicle and cause inflammation and acne |
|
Definition
|
|
Term
| regular inhabitants of the nose |
|
Definition
Staph epidermidis
Corynebacteria
Staph aureus (20% of population) |
|
|
Term
| Healthy sinuses are ________. |
|
Definition
|
|
Term
| normal inhabitants of pharynx (throat) |
|
Definition
streptococci
various Gram-neg cocci |
|
|
Term
| common pathogens that colonize the pharynx |
|
Definition
Strep pneumoniae
Strep pyogenes
Haemophilus influenzae
Neisseria meningitidis |
|
|
Term
| frequent inhabitants of upper respiratory tract (mainly pharynx) |
|
Definition
Neisseria
other Gram-neg cocci |
|
|
Term
| Why is the lower respiratory tract virtually free of microorganisms? |
|
Definition
| efficient cleansing action of the ciliated epithelium which lines the tract |
|
|
Term
| What can happen if the respiratory tract epithelium becomes damaged, as in bronchitis or viral pneumonia? |
|
Definition
| individual may become susceptible to infection by pathogens such as Haemophilus influenzae or Streptococcus pneumoniae descending from the nasopharynx |
|
|
Term
| The best sputum samples contain very little _______. More than ___ squamous epithelial cells at low enlargement indicates salivary contamination. |
|
Definition
|
|
Term
| What bacteria is present in the upper respiratory tract of about half the population and can cause pneumonia if it invades the lower respiratory tract? |
|
Definition
|
|
Term
| normal flora in oral cavity |
|
Definition
Viridans streptococcus
Actinomyces sp.
anaerobes |
|
|
Term
| What bacteria is responsible for causing dental plaques? |
|
Definition
|
|
Term
| normal flora in the stomach |
|
Definition
|
|
Term
| What is the primary bacterium involved in plaque formation and initiation of dental caries? |
|
Definition
|
|
Term
| normal flora in the small intestines and colon (scant in small bowel) |
|
Definition
Bacteroides (predominant organism)
Clostridium sp.
Escherichia
anaerobes (assorted gram-neg) |
|
|
Term
| What are the Gram-posn non-spore-forming, lactic acid bacteria that have been described as "friendly" bacteria in the intestine of humans? |
|
Definition
|
|
Term
| What is the predominant bacterial species in the intestine of breast-fed infants that prevents colonization by potential pathogens? |
|
Definition
|
|
Term
| What is a regular component of the intestinal flora that many European countries use as the standard indicator of fecal pollution (how we use E. coli here in the US)? |
|
Definition
|
|
Term
| What bacteria has emerged as a significant, antibiotic-resistant, nosocomial pathogen in recent years? |
|
Definition
|
|
Term
| What Clostridium bacteria is commonly isolated from feces? |
|
Definition
|
|
Term
| What bacteria may colonize the bowel and cause "antibiotic-induced diarrhea" or pseudomembranous colitis? |
|
Definition
|
|
Term
| What normal flora is found on both the skin and in the urethra? |
|
Definition
|
|
Term
| normal flora in the vagina |
|
Definition
Lactobacillus
yeasts
Streptococcus sp. (GBS in 15-20% of women) |
|
|
Term
| What bacteria colonizes the vaginal epithelium during child-bearing years and establishes the low pH that inhibits the growth of pathogens? |
|
Definition
| Lactobacillus acidophilus |
|
|
Term
| Why are yeast infections common in women taking antibiotics? |
|
Definition
| antibiotics kill off the Lactobacillus species that inhibit the growth of many other bacteria (such as yeast) |
|
|
Term
| The urethra may contain predominantly skin microorganisms including _____, ______, and _______. |
|
Definition
| staphylococci, streptococci, and diphtheroids |
|
|
Term
| normal flora of the anterior urethra |
|
Definition
Staph epidermidis
Enterococcus faecalis
some alpha-hemolytic streptococci
E. coli
Proteus
Corynebacterium
*contaminants from skin, vulva, rectum* |
|
|
Term
| What setting predispose a patient to alterations in the normal GI flora that can then cause UTI? |
|
Definition
frequent hospitalization
multiple courses of antibiotics given for other diseases |
|
|
Term
| What type of bacteria cause the majority of UTIs? |
|
Definition
| Gram-neg aerobic bacilli that arise from the GI tract |
|
|
Term
| second most common cause of UTI |
|
Definition
Staphylococcus saprophyticus
(coagulase-neg, Gram-pos)
not of fecal origin |
|
|
Term
| less common bacteria in UTIs |
|
Definition
Proteus
Klebsiella
Enterobacter |
|
|
Term
| normal flora in the blood, urine, and CSF |
|
Definition
|
|
Term
| microbial portals of entry |
|
Definition
mucous membranes
skin
parenteral |
|
|
Term
| What all must happen for successful entry into the host? |
|
Definition
-must access and adhere to host tissues
-must penetrate or evade host defenses
-must damage the tissue to cause disease |
|
|
Term
| What parasite can bore through intact skin? |
|
Definition
| Nectator americanus (hookworm) |
|
|
Term
| preferred portal of entry for Strep pneumoniae |
|
Definition
inhalation
(generally doesn't cause disease if swallowed) |
|
|
Term
|
Definition
| number of microbes that will kill 50% of inoculated test animals |
|
|
Term
|
Definition
| number of microbes that will cause a demonstrable infection in 50% of inoculated test animals |
|
|
Term
| Attachment between a microbe and a host tissue requires... |
|
Definition
| adhesins/ligands and receptors |
|
|
Term
| How do capsules help pathogens penetrate host defenses? |
|
Definition
-increase the virulence of many pathogens
-resist host defenses by impairing phagocytosis
(host can produce antibodies to capsule which attach to microbe and allow phagocytosis) |
|
|
Term
| What is found on the cell surface and fimbriae of Streptococcus pyogenes and mediates the attachment and helps resist phagocytosis? |
|
Definition
|
|
Term
| What are found on the cell wall of Mycobacterium tuberculosis and help resist digestion after phagocytosis? |
|
Definition
|
|
Term
destroy WBCs that are phagocytes
produced by staph and strep |
|
Definition
|
|
Term
destroy RBCs
produced by Clostridium perfingens (gangrene) and strep |
|
Definition
|
|
Term
produce clots in the blood, which may wall off site of infection from immune response
produced by some staph |
|
Definition
|
|
Term
break down clots produced by body to isolate infection
made by strep and staph |
|
Definition
|
|
Term
breaks down hyaluronic acid which holds cells together in connective tissue
made by some strep and gangrene causing clostridia |
|
Definition
|
|
Term
| bacteria responsible for gas gangrene |
|
Definition
|
|
Term
breaks down collagen
produced by several clostridia |
|
Definition
|
|
Term
|
Definition
|
|
Term
| destroys plasma membrane of cells |
|
Definition
|
|
Term
| break down proteins in tissue |
|
Definition
|
|
Term
surface proteins that alter actin filaments of the host cell cytoskeleton, allowing microbes to enter cells
Salmonella typhinurium
E. coli |
|
Definition
|
|
Term
| How do bacterial cells damage host cells (3 mechanisms)? |
|
Definition
-direct damage
-toxins
-hypersensitivity reactions |
|
|
Term
| What are frequently the main pathogenic factor in bacterial cell damage to host cells? |
|
Definition
|
|
Term
| ability of a microbe to produce toxins |
|
Definition
|
|
Term
| presence of toxins in the blood |
|
Definition
|
|
Term
| may include fever, CV problems, diarrhea, shock, destruction of RBCs and blood vessels, and nervous system disruptions |
|
Definition
|
|
Term
| _________ are produced inside mostly Gram-pos bacteria as part of their growth and metabolism and are then released into the surrounding medium. |
|
Definition
|
|
Term
| _________ are part of the outer portion of the cell wall of Gram-neg bacteria and are liberated when the bacteria die and the cell wall breaks apart. |
|
Definition
|
|
Term
|
Definition
| kill or damage host cells |
|
|
Term
|
Definition
| interfere with nerve impulses |
|
|
Term
|
Definition
| affect lining of GI tract |
|
|
Term
| toxins that have been altered by heat or chemicals and are used as vaccines for diphtheria and tetanus |
|
Definition
|
|
Term
| neurotoxin that inhibits release of neurotransmitter acetylcholine and prevents transmission of nerve impulses to muscles, causing flaccid paralysis |
|
Definition
|
|
Term
| neurotoxin that blocks relaxation of skeletal muscles, causing uncontrollable muscle spasms (lock jaw) and convulsions |
|
Definition
|
|
Term
| cytotoxin that inhibits protein synthesis in eucaryotic cells |
|
Definition
| Corynebacterium diphtheriae |
|
|
Term
| bacteria that produces three cytotoxins which damage blood capillaries, causing a red rash (scarlet fever) |
|
Definition
| Streptococcus pyogenes (erythrogenic toxin) |
|
|
Term
| exam finding of diphtheria |
|
Definition
|
|
Term
| enterotoxin that causes epithelial cells to discharge large amounts of fluids and electolytes |
|
Definition
|
|
Term
| staphylococcal infection that produces an enterotoxin similar to cholera toxin |
|
Definition
|
|
Term
| clinical manifestation of cholera |
|
Definition
profuse watery diarrhea
rice-water stools |
|
|
Term
| cause of scalded skin syndrome |
|
Definition
|
|
Term
| cause of toxic shock syndrome |
|
Definition
|
|
Term
| signs and symptoms of endotoxins |
|
Definition
chills, fever, weakness, general aches, blood clotting and tissue death, shock, even death
can also induce miscarriage |
|
|
Term
| Endotoxins do not promote the formation of effective ___________. |
|
Definition
|
|
Term
| organisms that produce endotoxins |
|
Definition
Salmonella typhi
Proteus sp.
Pseudomonas sp.
Neisseria sp.
E. coli |
|
|
Term
| events leading to fever with endotoxin infection |
|
Definition
1. Gram-neg bacteria digested by phagocytes
2. LPS released, causing release of IL-1
3. IL-1 carried bia blood to hypothalamus
4. IL-1 induces release of prostaglandins which reset the body's thermostat to a higher temp |
|
|
Term
|
Definition
| shock caused by endotoxins of Gram-neg bacteria (ex: E. coli) |
|
|
Term
| events leading to shock with endotoxin infection |
|
Definition
1. phagocytosis of Gram-neg bacteria causes secretion of TNF which alters the permeability of capillaries
2. large amounts of fluids are lost through capillaries
3. low blood pressure affects kidneys, lungs, and GI tract |
|
|
Term
| bacteremia vs. septicemia |
|
Definition
bacteremia: usually self-resolving, harmless
septicemia: often associated with severe disease |
|
|
Term
| small, circular pieces of DNA that are not connected to chromosomes and are capable of independent replication |
|
Definition
|
|
Term
| What do R factors (plasmids) contain? |
|
Definition
| antibiotic resistance genes |
|
|
Term
| can incorporate genetic material into chromosomal DNA and remain latent (lysogeny) |
|
Definition
|
|
Term
| When are blood cultures used? |
|
Definition
sepsis
any infection with circulating bacteria (endocarditis, osteomyelitis, meningitis) |
|
|
Term
| granules in cytoplasm or nuclei of virus-infected cells; may contain viral parts |
|
Definition
|
|
Term
| fusion of several adjacent cells to form a single giant cell |
|
Definition
|
|
Term
| What do you see in Tzanck preparation with HSV or varicella zoster? |
|
Definition
| multinucleated giant cell with intranuclear inclusion bodies |
|
|
Term
| cytological characteristic of CMV infected cells |
|
Definition
"owl eyes"
large, haloed basophilic intranuclear inclusions and intracytoplasmic granular inclusions |
|
|
Term
|
Definition
| herpes simplex virus (HSV) |
|
|
Term
| What determines the presence of antibodies specific for the bacteria using acute and convalescent serum samples? |
|
Definition
|
|
Term
| When is a throat culture used? |
|
Definition
| identify the cause of pharyngitis |
|
|
Term
| most common pharyngeal infections |
|
Definition
group A beta hemolytic strep
Strep pyogenes |
|
|
Term
| When is a sputum culture used? |
|
Definition
pneumonia
tuberculosis
lung abscess
bacterial, fungal, mycobacterial infections |
|
|
Term
| When is a CSF culture used? |
|
Definition
meningitis
Neisseria meningitidis
Streptococcus pneumoniae
Haemophilus influenzae
fungi (Cryptococcus neoformans)
viruses |
|
|
Term
| When is a stool culture used? |
|
Definition
diarrhea
enterics (Salmonella, Shigella, Campylobacter, Yesinia, Vibrio) |
|
|
Term
| When is a urine culture used? |
|
Definition
|
|
Term
| most common urinary pathogens |
|
Definition
E. coli
Proteus
Enterococcus |
|
|
Term
| What situation would make ANY bacteriuria significant? |
|
Definition
| pt. taking antibiotics (should not have ANY bacteria in urine) |
|
|
Term
| The majority of wound and abscess pathogens are _________. |
|
Definition
|
|
Term
| Brain, lung, and abdomen abscesses are usually... |
|
Definition
anaerobes
Bacteroides fragilis |
|
|
Term
| Traumatic open wounds are usually... |
|
Definition
soil flora
Clostridium perfringens |
|
|
Term
| Surgical wounds are usually... |
|
Definition
|
|
Term
| Human bites are usually... |
|
Definition
|
|
Term
| Dog or cat bies are usually... |
|
Definition
|
|
Term
| gold standard for viral infection |
|
Definition
| cell culture isolation and identification |
|
|
Term
| What solution is used for a wet mount checking for Cryptococcus sp.? |
|
Definition
|
|
Term
| What solution is used on a wet mount checking for fungi in skin, hair, or nails? |
|
Definition
| potassium hydroxide (KOH) |
|
|
Term
| diagnostic methods for parasites |
|
Definition
wet mount
stool ova and parasites (O&P)
special stained smear for protozoan cysts, trohpozoites, and helminth eggs
pinworm scotch tape slide prep
blood smear for malaria |
|
|
