Print › Micro Exam 3- Chapter 14

1/3: dry weight of feces that is made up of bacteria
anaerobic baceria: the general classification of 90% of all bacteria in the bowels
Bacteroides, clostridium, bifidobacterium, and fusobacterium: an anaerobic bacteria found in the lower intestinal tract
Bacteroids: anaerobic bacteria found in the mouth. commonly found in the gums
beneficial effects of normal flora: influence the pH, inactivate toxins, prevent bacteria from binding, stimulate our immune system,and provide supplemental vitamins
Bifidobacterium: the one bacteria that makes up the intestinal flora of infants who are being breastfed. this will be replaced by a wide variety of intestinal microbiota when introduced to solids. this promotes infant health and ferments milk sugars to acetic and lactic acids...making the low pH uninhabitable for many pathogens
bile: a biochemical defense that is a secretion produced by the liver and secreted into the intestines where it will kill many microorganisms by disrupting their cell envelopes. this is a specific antimicrobial effects.
broad-spectrum antibiotics: antibiotics that kill gram positive and negative bacteria....a wide range of bacteria, which allows opportunists to take over.
broad-spectrum antibiotics: antibiotics that act against a wide variety of bacteria.
Candida: an opportunistic fungal infection that takes over if lactobacillus is gone...due to something to the same effect as a broad-spectrum antibiotic
candida albicans: a yeast that is commonly found in small populations in our mouth. causes thruch
commensalism: one partner benefits and the other neither benefits nor is harmed. this is the relationship that exists between humans and members of their normal microbiota. the microorganishm benefits by being housed and fed. the host is largely unaffected. Since neither partner is harmed, this tends to be long-lasting and stable. usually are the product of long-term evolution.collectively the host does benefit
diptheroids: a bacteria that is found in the asal cavitity of up to 80% of the humans
dipthroids: bacteria found in the mouth
disease causing spectrum: the host's healthis critical in determining whether disease will occur therefor this continous view of pathogenic potential. ranges from highly virulent pathogens that cause disease in almost all cases --> opportunists which cause disease in weakened hosts --> avirulent commensal microbe are microbes that can sustain itself in the human body but has the potential of harming the host in a debilitating extreme
E. coli: a facultative anaerobe found in the lower intestinal tract and is the most common cause of UTI, it is an opportunistic pathogen
E. coli, enterobacterm enterococci, proteus, klebsiella: facultative anaerobes that are found in the lower intestinal tract
enterococci and staphylococcus epidermidis: bacteria found in the urethra
epethial surfaces: microbially colonized surfaces that are composed of cells that are tightly joined togeht to form a seamless and relatively impermeable barrier. these cells are constantly being replaced as they slough off. there are two main examples: skin and mucouse membranes
estrogen: the hormone that changes over the course of a woman's life. this is responsibel for the changes in the vagina
facultative anaerobes: a general classification of bacteria that are found in the lower intestinal tract...only about 10%. they are gram negative rods
fatty acids: a biochemical defense that is secreted by the skin in order to acidify the skin and make it inhospitable to microorganisms
first line of defense: structural defense, mechanical defense, biochemical defense
genetic exchange: conjugation and exchange of genetic information of the bacteria in the gut. one significant consequence of this can cause the intestinal population to become drug resistant
gnotobiotic: germ-free animals. their existance and success proves that animals can survive without resident flora. they are able to live a normal lifespan in a germ free environment
Haemophilus influenzae: a bacteria found in the nasal cavity that is a gram-negative pathogen...some strains of this bacteria are highly pathogenic while others are relatively harmless.
Haemophilus influenze: a bacteria that is almost always present in the mouth. this bacteria has the potential to infect the sinuses and the middle ear
host: the body that provides a habitat for its symbiotic partners
keratin: a biochemical defense found in the stratum corneum of the skin, a protein that is also found in nails. this is used in shampoo to add "body." this makes the skin dry, so it is inhospitable to microorganisms
Lactobacillus: the bacteria that is promoted by estrogen levels in the female. the amount therefor is variable over the course of life
Lactobacillus: the lactic acid bacteria that is found in the vagina that is responsible for the low pH and its primary inhabitants
Lactobacillus: a bacteria in the nasal cavity that is not commonly found on the skin
large intestines: home to a large number of diverse microorganisms. some toxic biochemical agents, like bile salt, are present...but intestinal movement is much slower and therefore microbial populations accumulate.
lysozyme: a biochemical defense that is an enzyme found in many secretions including tears and saliva, and it breaks specific chemical bonds in peptidoglycan cell wall
meconium: first stool from an infant's digestive system....it is free of microbes of any kind
Metabolism by microbes: disadvantage to resident flora. they can take up vitamin C and can produce carcinogens...they have the potential to be bad
microbial antagonism: one microorganism interferes with the growth of another. the collective advantage of commensalism, when microorganisms compete with pathogens so they can't establish an infection
mite: the only arachnid normally found on the human body. it lives on the face within hair fallicles and in the openings of sebacceous glands.
mouth: an environment of the body that is both good and bad for hosting microorganisms. it is good because it is warm, moist, and contains nutrients. But the saliva contains lysozymes and there is a lot of movement.
mucociliary system: a form of mechanical defense that is composed of a combination of mucus production and ciliary movement. cells on the surface produce a viscous mucus, forming a layer that entraps microorganisms. cilia on epithelial cells constantly move this mucous layer toward the mouth where it is swallowed and eliminated
mucous membrane: a type of epithelial surface...which acts as a structural defense...and can be found on internal surfaces or the conjunctiva. these are relatively thin and provide less protection than skin.
muscle movement: a form of mechanical defense that moves things down and out of these areas by underlying muscles
mutualism: a symbiosis in which both partners benefit. neither can survive without the other. this is highly evolved and extremely stable. no true form is found between humans and microorganisms because no single species is essential to our survival
normal flora: microorganisms that live with us stably. they are adapted to life in our body and under normal circumstances, they don't cause disease.
opportunists: microorganisms that cause disease when the proper "opportunity" arises, usually a breakdown in the immune system or the result of medical treatment
parasites: a term reserved for protozoa, worms, and insects.
parasitism: an unstable symbiosis that harms the host and the parasite benefits. either the host dies or successfully eliminates the pathogen from its body, these two organisms are poorly adapted to live together and have evolved only for a short period of time.
pathogen: microbial parasites
peristalsis: the wavelike muscular contractions that move food though the digestive tract. one of the microbial defenses that inhibit microbial growth in the esophagus
probiotics: a new technique that recognized that normal flora is good and uses bacteria to work to prevent viruses from binding to the cells.
resident flora: microorganisms that you always have with you throughout your life
salt: a biochemical defense that prevents bacterial growth, unless it is a halophile
second line of defense: inflammation... and innate immune defense
Staphylococcus: the genus of bacteria in the mouth that is very widespread...auereus is very common
staphylococcus aureus: a bacteria that is found in the nasal cavities of most humans
staphylococcus epidermidis: a bacteria that is also found in the nasal cavities of more than 90% of humans
Streptococcal mutans: causes tooth decay
Streptococcus: the genus of many of the bacteria that are found in the mouth. are found on the roof of the mouth, the tongue, and the mutans is found on the surface of the teeth
symbiosis: two kinds of organisms living together
third line of defense: specific immune response....an adaptive immune defense
transient flora: microbial species that come to rest on our body surfaces. most are not well enough adapted to life on the human body to persist there indefinitely. most members are harmless
Urethra: a part of the urinary tract that is hard for cells to attach to because it is composed of tightly joined epithelial cells that can resist attachment of microorganisms and the mechanical forces of urine flowing over the epithelial surface flush out microorganisms
washing effect: a form of mechanical defense that uses moving body fluids to bathe some surfaces and dislodge microbes