finals - fungal Flashcards
method under the molecular diagnosis with that particular
matter we can determine what type or what specific
organisms that would invade to a specific hosts.
RT PCT test
___ are microorganisms that survive by living off of other organisms, referred to as hosts.
Parasites
if we are dealing with a specific parasite, we
need to consider their ___
life cycle
Three types of organisms may cause parasitic
infections:
protozoa, helminths, and ectoparasites
the criteria to differentiate bacteria to parasite is
parasite is multicellular organisms
It is described that general concepts need to be considered in relation to host immune responses to
parasites:
Heterogeneity with respect to life cycles and
antigenic expression is a key feature of parasitic agents
Many parasitic infections are chronic in nature.
The mechanisms of immune evasion are
significantly different from those of bacterial
infections.
Many parasites develop significant genetic and
antigenic variation in a relatively short period.
The innate immunity in the natural hosts may be genetically determined
Humans, as well as animals, differ widely in their ability to handle the complex antigens found in parasites
___ with respect to life cycles and
antigenic expression is a key feature of parasitic agents.
Heterogeneity
Defenses to parasitic infection involve what type of immunity?
both innate and acquired (adaptive) immune mechanisms
the ___ immunity are preventing the establishment of a parasitic infection
innate
The nonspecific immune defenses can include activation of cells that may destroy the parasite by phagocytosis,
release of cytokines such as:
TNF-α, IL-1, IL-10, IL-12,
type I interferons, and chemokines
aside from phagocytosis and releasing of cytokines, it will be activatd as well to combat parasites to enhance immunity to recognized foreign materials
activation of complement system
if the innate immunity didn’t work to combat parasites, what will happen?
adaptive immunity will take place - producing antibodies
humoral branch of adaptive immunity
production of antibodies
Another feature that we have under the adaptive immunity would be the cell mediated response which composed of
t cells
potential outcome of host and parasite interactions
level 1
natural resistance - no invasion of the parasites
potential outcome of host and parasite interactions
level 2
symbiosis
colonization of host with parasite with benefit to both
potential outcome of host and parasite interactions
level 3
commensalism
colonization of host with parasite with no benefit or harm
potential outcome of host and parasite interactions
level 4
sterilizing immunity
parasite invades host and causes disease; host develops immunity and is cured
potential outcome of host and parasite interactions
level 5
concomitant immunity
parasite invades host and causes disease; host develops an immune response and has some resistance to the parasite but is not cured
potential outcome of host and parasite interactions
level 6
ineffective immunity
parasite invades host and causes disease; host does not develop resistance to the parasite and is not cured
which antibodies are best known for their role in allergic reactions.
IgE
IgE, Aside from parasitic infection, this will be in line with the _____
allergic reaction.
IgE antibodies, play an important role in the defense against parasites
such as ___, which are too large to be phagocytized.
helminths
mechanism of IgE, Killing of the parasites is accomplished by ___
ADCC (Antibody-dependent cellular cytotoxicity).
In ADCC, In this mechanism, the ____ portions of the parasite-specific
IgE antibodies bind to specific receptors on the surface of ___, which are then stimulated to release ENZYMES from their granules that destroy the parasite.
Fc ; eosinophils
SEROLOGY INDICATED - useful ang serology to detect the following parasitic infection
amebiasis (extraintestinal)
chagas disease
clonorchiasis
cysticercosis
hydatidosis
filariasis (lymphatic; suspect cases when microfilariae cannot be identified in blood)
leishmaniasis (cutaneous and visceral)
schistosomiasis (ectopic cases, chronic cases when eggs cannot be demonstrated in feces or urine)
toxocariasis (visceral and ocular)
trichenellosis
SEROLOGY MAY BE USEFUL
amebiasis
amebic meningoencephalitis (caused by free living amebae)
anaplasmosis/ehrlichiosis
babesiosis
lyme disease
paragonimiasis (eggs not detectable in sputum or feces)
SEROLOGY NOT INDICATED
anisakiasis
ascariasis
capillariasis
cryptosporidiosis
hookworm
malaria
trichuriasis
escape mechanisms of parasites from protective host responses
escape mechanism - antigenic concealment
nature of response - intracellular survival within macrophages
escape mechanisms of parasites from protective host responses
escape mechanism - antigenic concealment
example
leismania donovani
escape mechanisms of parasites from protective host responses
escape mechanism - antigenic variation
nature of response
- random mutation
- genetic recombination
- gene switching
- multistage parasitic life cycle
escape mechanisms of parasites from protective host responses
escape mechanism - antigenic variation
example
plasmodium species
trypanosoma cruzi, gambiense, rhodesiense
leishmania species
escape mechanisms of parasites from protective host responses
escape mechanism - antigenic mimicry
nature of response - incorporation of host “self” antigens into parasite surface
escape mechanisms of parasites from protective host responses
escape mechanism - antigenic shedding
example
entamoeba histolytica
escape mechanisms of parasites from protective host responses
escape mechanism - antigenic shedding
nature of response - shedding of surface antigens or components
escape mechanisms of parasites from protective host responses
escape mechanism - antigenic mimicry
example
schistosoma species
escape mechanisms of parasites from protective host responses
escape mechanism - immunologic subversion
nature of response - immunosuppresion
escape mechanisms of parasites from protective host responses
escape mechanism - immunologic subversion
example
schistosoma mansoni
escape mechanisms of parasites from protective host responses
escape mechanism - immunologic diversion
nature of response - polyclonal b cell activation
escape mechanisms of parasites from protective host responses
escape mechanism - immunologic diversion
example
plasmodium species
___ represent a large heterogeneous group of
eukaryotic organisms that are ubiquitous in the environment
Fungi
Fungi can either be considered as ___, deriving their
nutrition from living matter, or more commonly as
____, living off of dead and decaying matter
parasites; saprophytes
If the fungi penetrate the physical barriers, there are a variety of innate mechanisms for recognizing the organism. Innate immune cells express various ____that recognize
specific structures and molecules present on bacteria and fungi
pattern-recognition receptors (PRRs)
the structure of microorganisms that are recognized by the prr
These structures and molecules of the organism, called
___ are conserved among microbial species
pathogen-associated molecular patterns (PAMPs),
> particular fungus found in the urine of
diabetic patient.
Candida albicans
representative agers for superficial mycotic infection
malassezia furfur
phaeoellomyces werneckii
piedraia hortae
trichosporon species
representative agents for cutaneous mycotic infection
trichophyton species
microsporum species
epidermophyton floccosum
representative agents for subcutaneous mycotic infection
sporothrix schenckii
fonsecaea pedrosoi
pseudallesscheria boydii
representative agents for systemic mycotic infection
histoplasma capsulatum
coccidiodes immitis
paracoccidioides brasiliensis
blastomyces dematitidis
penicillium marneffei
cryptococcus neoformans
representative agents for opportunistic mycotic infection
candida albicans
aspergillus species
rhizopus species
representative agents for commensalistic mycotic infection
candida albicans
malassezia furfur
