Term
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Definition
| a disease in which a pathogen invades a susceptible host and carries out at least part of their lifecycle in the host. |
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Term
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Definition
something's that part of the body, part of the normal flora but it can become an infection in large enough numbers
ex) yeast infection, e coli, staff infection |
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Term
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Definition
something from outside the body, may be part of the normal flora, but more typically is something that isn't part of the normal flora
ex) herpes |
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Term
| resistance to antibiotics, pathogens that mutate, population density (easier to spread), travel (exposure to more pathogens), people not getting vaccinated |
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Definition
| why is there an increase in death from infectious disease? |
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Term
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Definition
replicate inside the host and typically produce a large # of progeny and potentially a serious infection
ex) bacteria, viruses, fungi, and protazoa |
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Term
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Definition
typically have one infectious stage maturing into a reproducing stage, with the offspring exiting the host to continue the cycle. The level of the infection is dependent on the number of organisms that entered the body.
ex) arthropods, worms, helminthes |
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Term
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Definition
| have access to the host's nutrient supply, genetic material, and can avoid the host's immune system and antimicrobial protective mechanisms. |
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Term
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Definition
can feed on host cells or take up nutrients from tissue fluids or gut contents.
many can spread rapidly through extracellular fluids or over host surfaces |
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Term
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Definition
| term used to refer to an organism which itself does not cause disease but allows the transmission of disease causing microbes |
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Term
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Definition
| protazoa that directly causes disease |
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Term
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Definition
true or false
bacteria are more advanced than protazoa with respect to their metabolic function. |
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Term
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Definition
| bacteria are prokaryotes. pro means before and karyote means... |
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Term
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Definition
single celled prokaryotes
DNA is in a long circular molecule devoid of an envelope but found in the region called the nucleoid
the cell wall is complex and there is often a thick capsule
no organelle other than ribosomes
some possess flagella for motility
pili function in the passage of DNA from one organism to another
fimbriae function in the attachment to other bacteria or a host
a mesosome is a coiled cytoplasmic membrane that anchors chromosomes |
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Term
| bacterial "sex" via the transfer of DNA from one bacterium to another |
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Definition
| a bacterial pilus is an organelle that functions in... |
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Term
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Definition
| have access to the host's nutrient supply, genetic material, and can avoid the host's immune system and antimicrobial protective mechanisms. |
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Term
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Definition
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Term
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Definition
| unable to use oxygen for energy yielding reactions. are harmed by oxygen |
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Term
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Definition
| can use oxygen when it is present but are able to continue growth via fermentation or anaerobic respiration when oxygen isn't available |
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Term
bacteria are heat fixed or dried on a slide
stained with crystal violet and Gram's iodine
excess stain is removed by washing with acetone-based decolorizer and water
red counterstain (safranin) is added |
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Definition
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Term
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Definition
thick multilayered cell wall made mainly of peptidoglycan around the cell membrane
peptidoglycan can block phagocytosis and induce fever
degraded with lysozymes
may contain teichoic and lipoteichoic acids and polysaccarides
outer membrane: no
lysozyme: sensitive
cell wall: thicker
lipopolysaccaride: no
endotoxin: no |
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Term
gram negative bacteria
structurally and chemically more complex than gram positive cell walls |
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Definition
outer membrane is hydrophilic but also hydrophobic due to lipids
special pores made of proteins (porins) allow passage of nutrients
LPS confers antigenic and toxic properties
outer membrane: yes
lysozyme: resistant
cell wall: thinner
lipopolysaccarides: yes
endotoxin: yes |
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Term
starved cells
old cells in the stationary stage
treated with antibiotics
mycobacteria (waxy outer shell), mycoplasmas (no peptidoglycan) |
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Definition
| when does gram staining not work? |
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Term
spherical
rod shaped
spiral |
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Definition
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Term
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Definition
bacteria take up fragments of naked DNA and incorporate them into their genome
some species are competent, naturally taking up exogenous DNA |
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Term
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Definition
| a one way transfer of DNA from a donor (male) to a recipient (female) cell through the sex pilus |
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Term
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Definition
| the transfer of genetic material from one bacteria to another via a bacteriophage (bacterial viruses with extrachromosomal genetic elements). once in a cell, a transposon can jump between plasmid to plasmid or plasmid to chromosome. |
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Term
1) production of the basic building block (UDP-acetylmuramyl-pentapeptide), takes place inside the cell. Cycloserine, a rather toxic antibiotic that is employed rarely in the treatment of mycobacterial infections, inhibits the terminal reactions in this sequence.
2) the precursor unit is carried from inside the cell membrane to outside. During this process, a number of modifications occur in the chemical structure of the basic repeating unit; they are linked covalently to the pre-existing cell wall. Vancomycin and bacitracin act during this second stage.
3) takes place entirely outside the cell membrane and consists of a variety of reactions that cross link and modify the wall components (the cross linking enzymes and some of the modifying enzymes are inhibited by penicillins and cephalosporins) |
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Definition
| cell wall synthesis can be divided into these 3 stages |
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Term
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Definition
| repeating unit of cell wall synthesis has a common terminal in all bacteria (gram - or +) |
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Term
1) initiation: involves formation of an initiation complex. In bacteria, the first aa is formylmethionine. Formylmethionine and its appropriate tRNA are first united under the direction of an aminoacyl-tRNA-synthetase to form the aminoacyl-tRNA
2) elongation: at the end of initiation, the ribosome is ready to translate the reading frame associated with the initiation codon. Elongation is accomplished by the sequential repetition of three reactions with each aa.
3) termination: the elongation process continues until a termination sequence containing code triplets UAA, UGA, or UAG in the mRNA signals that the protein chain is complete. The termination codon is not an aminoacyl-tRNA. The ribosome binds a protein called "termination release factor" which recognize the termination codon in the A site. The peptidal transferase works now as an esterase that releases the peptide. The ribosome is released.
in each stage a different set of protein factors is utilized by the ribosome. These factors cycle on and off the ribosome and allow the ribosome to interact with them sequentially at a single site. |
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Definition
| 3 stages of protein synthesis (process of mRNA translation) |
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Term
| given to patients who have a suspected infection |
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Definition
| empiric antibiotic therapy |
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Term
| very specific for the identified pathogen |
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Definition
| definitive antibiotic therapy |
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Term
| patient doesn't have infection, but may have the risk |
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Definition
| prophylaxis antibiotic therapy |
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Term
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Definition
gram positive bacteria
shape: cocci clusters
coagulase + (coagulase is a protein produced by some microorganisms) |
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Term
| Staphylococcus epidermidis and Staphylococcus saprophyticus |
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Definition
gram positive bacteria
shape: cocci clusters
coagulase negative (coagulase is a protein produced by some microorganisms) |
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Term
| Streptococcus pneumoniae and Streptococcus viridians |
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Definition
gram positive bacteria
shape: cocci chains
alpha-hemolysis (the agar is dark or green) |
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Term
| Streptococcus pyogenes and Streptococcus agalactiae |
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Definition
gram positive bacteria
shape: cocci chains
beta-hemolysis (the agar is yellow) |
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Term
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Definition
gram negative bacteria
shape: bacillus
respiration: aerobic
glucose fermentation (lactose +) |
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Term
| E. coli, Klebsiella, and Salmonella |
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Definition
gram negative bacteria
shape: bacilli
respiration: aerobic
glucose fermentation (lactose -) |
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Term
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Definition
aren't living
obligate intracellular parasites
must be infectious to survive in nature
cannot make energy or proteins independent of a host cell
contain RNA OR DNA (whereas living organisms contain RNA and DNA)
have to be able to use host processes to produce proteins, viral mRNA, identical copies of the genome.
single (ss) or double stranded (ds), linear or circular DNA or RNA within a capsule (capsid)
may only be a nucleocapsid or it may have an outer membrane or envelope (derived from the host cell)
[image] |
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Term
[image]
host specificity is due to the ability of the virus to attach to the host cells receptor molecules |
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Definition
| stages in the infection of a host cell and the replication of the virus |
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Term
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Definition
| viral infection where the virus replicates, produces new viruses, and they are released when the cell lyses. |
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Term
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Definition
| viral infection where the cell survives and releases particles slowly |
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Term
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Definition
viral infection where the virus is quiescent (dormant) with the DNA or RNA existing in the host's cytoplasm (herpes) or in the host's genome (retrovirus)
replication takes place when some type of activation occurs. |
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Term
biochemical properties: mode of replication
structure: size, morphology, nucleic acid
associated disease
mode of transmission
host cell: animal, plant, bacterium
target tissue or organ |
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Definition
| methods of classifying viruses |
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Term
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Definition
| modes or viral transmission |
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Term
fungal cell
ergosterol in the cell wall instead of cholesterol
different antifuncals are going to target different parts of the cell or the cell cycle |
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Definition
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Term
multicellular, branching filamentous (hyphae) forms or as unicellular yeast
filamentous forms, mass of hyphae is called a mycelium; asexual reproduction results in spores
yeasts reproduce by budding or fission (division) |
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Definition
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Term
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Definition
| fungal infection of the body surface (skin, hair) |
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Term
| cutaneous or subcutaneous |
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Definition
| fungal infection of the nails or subcutaneous area of the skin |
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Term
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Definition
| fungal infection of the internal organs |
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Term
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Definition
| fungal infection that causes disease in immune compromised hosts |
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Term
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Definition
single celled animals
cytoplasm enclosed by a cell membrane and many organelles (ex. nucleus, ER, vacuoles)
move via pseudopods, flagella, cilia |
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Term
usually asexual (binary or multiple division)
sexual (rare) in an arthropod vector |
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Definition
| methods of protozoal reproduction |
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Term
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Definition
most common in tropical, subtropical regions but many in temperate
intracellular parasites infect RBCs, macrophages, brain, muscle, and epithelial cells. Nutrient uptake from host cells.
Extracellular pathogens infect the blood, intestines, urinary or reproductive tracts. Feed by nutrient uptake from host cells or ingest the whole cell. |
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Term
ingestion of cysts in contaminated food or drink (Giardia)
sexual contact; reside in urogenital tract
arthropod vectors (malaria); reside in blood or other tissues |
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Definition
| modes of transmission for protozoa |
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Term
some can:
continuously change their surface antigens
develop into a cyst form in harsh conditions
consume compliment at the cell surface
intracellular protozoa can evade intracellular enzymes
facultative anaerobes
for example: Giardia lamblia has a cyst form and it has a ventral sucker that allows it to attach to human intestines |
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Definition
| protozoan survival mechanisms |
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Term
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Definition
helminth
flatworm
tapeworm
has suckers/hooks |
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Term
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Definition
helminth
flatworm
fluke
has suckers/hooks |
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Term
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Definition
helminth
roundworm
no attachment organs |
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Term
parasitic worms
all organs in the body can become infected
larvae are macroscopic
adults are macroscopic (cm-m)
anaerobic respiration (predominantly)
flatworms do have attachment organs
roundworms do not have attachment organs
many lack a digestive system (flukes absorb food via the cuticle)
they have a simplified and reduced nervous system
their means of movement are dramatically reduced
they have a complex reproductive system in which they produce large numbers of eggs for infection |
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Definition
| characteristics of helminthes |
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Term
[image]
risk factors: low sanitation, walking barefoot, eating uncooked or undercooked meat, insect bites |
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Definition
| modes of helminth transmission |
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Term
| simple tapeworm lifecycle |
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Definition
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Term
complex life cycle
goes through humans and it can go through an intermediate host (2 loops) |
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Definition
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Term
arachnida: spiders, ticks, mites
insecta: mosquitoes, fleas, lice |
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Definition
| 2 phylum of arthropods that cause infectious disease |
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Term
directly by feeding on host's tissue/blood
indirectly via transmission |
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Definition
| modes of disease transmission for arthropods |
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Term
malaria from mosquitoes
lyme disease from ticks
plague from fleas |
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Definition
| examples of disease transmitted by arthropods |
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Term
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Definition
| provides an environment for another organism |
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Term
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Definition
| utilizes the environment of the host for nutrients |
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Term
In the respiratory tract there are macrophages in the alveoli that will get rid of a pathogen through phagocytosis.
In the GI tract bacteria can attach to the epithelium, but the body blocks this attachment by increasing acid and mucous production.
In the urinary tract, the acidity of urine kills some pathogens and urine can also flush out pathogens. |
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Definition
How does the body respond to or get rid of extracellular bacteria?
respiratory tract?
GI tract?
urinary tract? |
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Term
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Definition
| presence of a particular type of microorganism in a part of the body not normally found. |
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Term
flora
members of normal flora can be harmful if they enter sterile areas of the body |
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Definition
| microorganisms that are colonized in the body that do not produce disease. |
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Term
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Definition
| parasite/bacteria may benefit but the host may not be affected |
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Term
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Definition
| a relationship with mutual benefits, both the host and the parasite benefit |
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Term
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Definition
| a relationship where only the parasite/bacteria benefit at the expense of the host |
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Term
1) the microbe must be present in every case of the disease
2) the microbe must be isolated from the diseased host and grown in pure culture
3) the disease must be reproduced when a pure culture is introduced into a non-diseased susceptible host
4) the microbe must be recoverable from an experimentally infected host
exceptions to the rule:
some microbes cannot be grown in the laboratory
some diseases have more than one microbe involved |
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Definition
| 4 rules of Koch's postulate |
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Term
swallowing/coughing/sneezing
mucous production that traps bacteria and the cilia move the mucous down the throat |
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Definition
| what are 2 mechanisms that help cleanse the upper respiratory tract? |
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Term
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Definition
| what is the most common infectious disease? |
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Term
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Definition
toxic proteins produced by some bacteria (mostly gram positive) and secreted or released after lysis.
metabolic product of growing cell
high toxicity but not fever producing
can be destroyed more easily (unstable) |
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Term
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Definition
part of the outer portion of the cell wall (lipid A) of most gram negative bacteria, released on destruction of the cell.
low toxicity and fever producing
harder for the body to destroy |
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Term
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Definition
causes steptococcal pharyngitis (strep throat)
gram positive coccus (chains); facultative anaerobe
also infects other areas of the URT, skin, kidneys, etc.
produces many exotoxins and enzymes
the cause of 95% of bacterial sore throats
it can spread initially, causing ear infections. If it becomes systemic it can cause scarlet fever (disorder of the heart valves) |
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Term
| cytomegalovirus (CMV) infection |
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Definition
causes pharyngitis
largest human herpes virus (Herpesviridae)
acquired from most bodily secretions and blood
originally called salivary gland virus - transmitted by salivary glands
persistent and latent infections; remains latent in neutrophils, t-cells, monocytes
often asymptomatic but can spread to lymphoid tissue (agranulocytes in the spleen, lymph nodes), then salivary glands, kidneys, reproductive organs (shed)
dangerous to babies (mental retardation, congenital abnormalities), immune impaired |
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Term
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Definition
herpesvirdidae; transmitted in saliva
replicates in B-cells
virus is shed in saliva from infected salivary gland and oropharynx epithelial cells, spreads to B-cells in lymphoid tissue
T-cells respond to infected B-cells, become hyperplastic (increase in number)
infectious mononucleosis (fever, anorexia, lethargy, splenic rupture) |
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Term
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Definition
causes parotisis: mumps
typically airborne or salivary secretion transmission; lytic infection
life long resistance to reinfection |
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Term
Pseudomonas aeruginosa
may also be caused by: staphylococcus aureus or candida albicans; found as normal flora of the skin |
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Definition
causes otitis externa: swimmer's ear
gram negative bacillus
aerobic
it produces an exotoxin and an endotoxin |
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Term
Streptococcus pneumoniae; gram positive diplococcus, falcultative anaerobe
Haemophilus influenzae; gram negative bacillus, facultative anaerobe
RSV (respiratory syncytial virus)
Streptococcus pyogenes |
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Definition
| 4 of the possible causes of otitis media or sinusitis |
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Term
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Definition
causes epiglottitis
typically small children
called the most threatening disease of the URT |
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Term
| Streptococcus pyogenes or Streptococcus pneumoniae |
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Definition
causes laryngitis/tracheitis
pain during inhalation/exhalation, hoarseness |
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Term
| Respiratory Syncytial Virus |
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Definition
is a paramyxovirus (like mumps)
it is the most common cause of bronchiolitis and pneumonia in children under 2
it inflames bronchioles and restricts air to alveoli
is an enveloped virus that possesses a fusion protein in its envelope. This confers the ability of the virus to fuse with the host cell membrane and thus allow entry of the infectious genomic material into the cell cytoplasm. During replication of the virus, expression of the fusion protein at the cell membrane can result in the fusion of neighboring cells, and the formation of multinucleated cells or syncytia. |
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Term
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Definition
example etiological agents: rhinoviruses, coronaviruses (like common colds), influenza virus. Also caused by allergies and smoking.
Cough due to: irritation of bronchi, excess mucous, cilia impaired.
Plugging of small airways.
Effects the heart b/c there is decreased O2 supply. |
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Term
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Definition
acute inflammation of the lung.
air spaces become filled with inflammatory exudate.
most common cause of infection-related death in the US and Europe
Adults: bacterial causes more common than viral (ex. streptococcus pneumoniae)
Children: mainly viral (RSV)
pathogens reach alveoli by inhalation of aerosolized materials or by aspiration of normal flora of the URT |
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Term
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Definition
inflammation of the pleural membranes
can occur as a result of pneumonia or tuberculosis
usually caused by a viral pathogen
very painful; sharp, stabbing pain accompanies each inspiration |
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Term
influenza viral infection
influenza A - epidemics, pandemics with animal reservoirs
influenza B - epidemics, no animal hosts
influenza C - mild |
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Definition
an orthomyxovirus
can cause endemic (very localized), epidemic (wider population), and pandemic (worldwide)
fever, myalgia, headache, pharyngitis
[image]
H spikes allow viral recognition to host and attachment
N spikes help virus exit the infected host cell
viral strains based on H and N antigens |
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Term
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Definition
causes whooping cough (pertussis)
gram negative coccobacillus
aerobic
attaches to and multiply in ciliated tracheal cells but don't invade deeper
many toxins: tracheal cytoxin damages ciliated cells, pertussis toxin causes systemic symptoms, endotoxin
cold symptoms, gasping for air (whoop); secondary complications can be CNS, anorexia, secondary pneumonia
major cause of death world wide |
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Term
| Mycobacterium tuberculosis |
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Definition
causes tuberculosis
gram positive bacillus
aerobic
***waxy outer coat***, grows slowly and in clumps
acquire by inhalation; if infective dose low, can fight via activated macrophages. If not:
1) Bacteria are ingested by alveolar macrophages and walled off in alveoli (tubercle)
2) lesion becomes calcified
3) if defenses fail, tubercle breaks down and bacilli are released into respiratory, lymphatic and cardiovascular systems
TB patients respond with cell mediated immunity rather than humoral. this is the basis of the tuberculin skin test. |
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Term
only need a small amount to become infected
people can live with it unknowingly for years and spread it during this time
waxy outer coat makes it difficult for the macrophages to destroy
waxy outer coat also makes it possible for it to live outside of a human host |
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Definition
| Why is Mycobacterium tuberculosis so successful? |
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Term
|
Definition
many species, spores inhaled regularly; most harmless
Aspergillus fumigatus can cause allergic bronchopulmonary aspergillosis or aspergillomas - fungal balls of entangled hyphae |
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Term
|
Definition
found in feces of starling, pigeons, chickens, bats. (soil with high nitrogen content)
is dimorphic - yeast like in tissue growth, filamentous in soil
resembles TB - lesions in lungs but spread via blood and lymphatics
usually asymptomatic but 0.1% can be severe
found in states along Mississippi and Ohio borders |
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Term
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Definition
| a disease characterized by frequent, watery stools containing blood and mucus |
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Term
|
Definition
| inflammation of the epithelial lining of the SI or LI |
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Term
|
Definition
| inflammation of the epithelial lining of the stomach and intestines |
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Term
When you ingest a toxin in large enough amounts that they cause damage
ingestion of pre-formed toxins |
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Definition
| What does the word intoxication mean? |
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Term
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Definition
| defense mechanisms of the GIT |
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Term
|
Definition
bacterial cause of diarrhea
gram negative bacillus
facultative anaerobe, motile
normal gut inhabitant
endotoxins (all strains); enterotoxins associated with diarrhea
5 groups associated with gastroenteritis |
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Term
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Definition
type of E. coli that reduces the surface area of the SI by destroying microvilli
interferes with SI absorption resulting in diarrhea
non invasive
does not produce toxins |
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Term
|
Definition
type of E. coli that secretes toxins when in the GI tract
the toxins can increase GI motility b/c the intestines want to get rid of the toxin.
the immune system secretes prostaglandins, cytokines to increase contractions in response
non-invasive |
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Term
| enteroaggregative E. coli |
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Definition
type of E. coli that causes a decrease in surface area in the SI
the body responds to the bacteria by producing a lot of mucous and traps the bacteria in an aggregate, eventually the mucous will break down the microvilli
non invasive |
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Term
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Definition
type of E. coli that causes hemorrhage
secretes an extremely potent toxin (similar to the shiga toxin), breaks down LI lining
as few as 100 bacteria can cause disease
invasive |
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Term
|
Definition
type of E. coli that invades the epithelial cells of the LI via endocytosis, toxins then enter the cell
lives in the endocytotic vesicle, replicates, and can become systemic if it passes through the basement membrane
invasive |
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Term
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Definition
bacterial cause of diarrhea
gram negative bacillus
microaerophilic
flagellar motility
contaminated food and milk
animal reservoirs (sheep, cow, chicken, cats, dogs, birds)
bloody stools due to damage of the mucosal surface of the jejunum
most common cause of bacterial gasteroenteritis in the US |
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Term
Salmonella spp.
many species and serotypes but S. enterica is important in human infection |
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Definition
bacterial cause of diarrhea
gram negative bacillus
facultative anaerobe
most common cause of food born diarrhea in most developed countries
humans acquire from poultry, meat, eggs, milk
usually an acute infection and self-limiting except in the young and old
invade epithelial cells of the ileocecal region and migrate to the lamina propria |
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Term
|
Definition
bacterial cause of diarrhea
gram negative bacillus
facultative anaerobe
single flagellum
virulence factors such as an enterotoxin
strictly a human pathogen causing cholera
colonization in the SI, enterotoxins cause rice water stools |
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Term
|
Definition
bacterial cause of diarrhea
4 species cause bacillary dysentery (shigellosis)
gram negative bacillus
facultative anaerobe, non motile
invades ileum, colon epithelial cells; rarely invades bloodstream
exotoxin (Shiga toxin - very lethal, similar to enterohemorrhagic E. coli)
usually transmitted via poor sanitation, overcrowding |
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Term
|
Definition
| Over 3 million infants die of gastroenteritis each year, and ( ) are the most common cause. |
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Term
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Definition
causes viral diarrhea
attach to the intestinal epithelium, damage transport mechanisms in the intestines
most cases of viral gastroenteritis are diarrhea mechanism:
[image]
attach to epithelium and invade apical regions of the villi, don't go into the crypts. The tip of the villus will be destroyed, but the crypt cells will continue replicating so normal epithelium will be restored in 1 week. |
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Term
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Definition
causes food poisoning caused by toxins from bacteria in food
gram positive coccus
facultative anaerobe
enterotoxins act as superantigens binding to MHC causing T-cell stimulation
heating can kill bacteria, toxins survive |
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Term
|
Definition
causes food poisoning
gram positive bacillus
anaerobe
common pathogen in birds, mammals; soil is normal habitat
exotoxin (Botulinum toxin) produced in the gut after bacterium are ingested or from improperly canned or reheated food, absorbed from the gut into the blood
site of action of the toxin are the nerve synapses |
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Term
|
Definition
causes gastric ulcers
gram negative
microaerophilic bacterium involved in the majority of gastric and duodenal ulcers
adhesins, urease, cytotoxins disrupt stomach and SI mucosa |
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Term
|
Definition
causes typhoid fever
gram negative bacillus
facultative anaerobe
pathogen not found in animals, only spread by human fecal/oral route
pathogens multiply in phagocytic cells, spread to the liver, spleen, and lyse, becoming blood borne
frequent cause of death in parts of the world with poor sanitation
much more serious than salmonellosis
can become chronic carriers |
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Term
|
Definition
single stranded RNA, can be grown in cell culture
picornaviridae
hepatovirus
spread by fecally contaminated food, water, hands, or by anal intercourse
multiplies in the intestinal epithelium, spreads to the liver, kidneys, spleen
usually no lasting or permanent liver damage |
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Term
|
Definition
protozoan infection
causes amoebic dysentery or amoebiasis: mild to severe diarrhea with blood, mucus, puss in stool
food or water contaminated with cysts; stomach acid doesn't effect cysts
worldwide but common in tropical countries
Cycle starts in the encysted form that is excreted in the feces and if ingested will travel to the SI. Break out of the cyst and turn into the mature vegetative form. Remains in the intestines, can travel in the mature form in the circulation and infect the brain. |
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Term
|
Definition
protozoan infection
causes giardiarsis
mild to severe diarrhea with cyst and trophozoite form
adhere to the microvilli of the SI
most commonly diagnosed intestinal parasite in the US |
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Term
|
Definition
helminth (nematode) infection
causes ascariasis; roundworm infection
spread via a fecal/oral route
adult worms migrate
usually not severe symptoms but can cause duct blockage
[image]
stages of life cycle: 1) in the SI, reproducing adults, potentially producing fertilized eggs 2) fertilized eggs excreted in the feces 3) fertilized egg is in the infective stage, turns into larva form still in the egg 4) ingestion of egg 5) larvae hatches/growth in the intestines 6) migrates to lungs via the circulatory system 7) coughed up from the lungs and swallowed and the life cycle repeats |
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Term
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Definition
helminth infection
causes hookworm disease
once common in the SE US
hookworm attaches to intestinal wall, feeding on blood, tissue (not food); may cause anemia
[image]
1) eggs are excreted 2) larva hatch in nature (different than Ascaris lumbricoides) 3) larvae grow 4) bore into feet 5) enters circulation, goes to lungs, swallowed, attach to the SI (all in the larvae form then mature into adults in the SI) |
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Term
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Definition
helminth infection
causes pinworm disease
migrates out of the anus to lay eggs; if ingested, larvae hatch in the SI
best detected with a Graham sticky tape method
most common helminth in the US |
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Term
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Definition
helminth (cestode) infection
tapeworm
3 stages:
1) adult worm in intestines of humans, eggs excreted in feces
2) eggs ingested by grazers and hatch into larvae
3) humans eat undercooked meat, larvae develop into adults that attach to walls of SI |
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Term
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Definition
fungal infection of the GI tract: aflatoxin poisoning
a common mold
produces a mycotoxin, aflatoxin
many foods, particularly peanuts and corn
may contribute to liver CA and cirrhosis
most potent natural carcinogen known |
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Term
tuberculosis
aspergillosis
histoplasmosis
cystic fibrosis |
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Definition
| chronic lower respiratory tract infections |
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