Infectious disease Flashcards
endemic disease
sporadic in the community
epidemic
clusters of disease in an area or region with rapid spread
pandemic
excessive epidemic that crosses continents
what are three diseases responsible for past pandemics
- smallpox
- typhus
- influenza
what is the human metagenome
the human genome plus the DNA of the symbiotic microorganisms that live in humans
why is restoring a normal microbiome important?
what is one therapy that focuses on this concept?
normal microflora help crowd out or actively fight some pathogenic agents
fecal transplant in the case of c diff
what are infectious agents?
transmissable cause of disease
three types of microbe
- bacteria
- fungi
- unicellular eukaryotes
what are the three classifications of infectious agents (2 examples each)
- Eukaryotes (protists and fungi)
- prokaryotes (bacteria, mycoplasm)
- non-living (viruses, prions)
what is the simplest known infectious agent
prions
what do prions cause?
what are two diseases caused by prions
transmissable spongiform encephalopathy
creuztfeldt-jakob and BSE
how do viruses infect a host cell?
once insde the cell what will a virus do
receptors on the protein coat bind to cell receptors and either inject DNA into the cell or allow for passage of the whole virus
once inside the virus will replicate its genome to produce new viral apparati and assemble new viral particles
three diseases caused by RNA viruses
- influenza
- HIV
- Polio
three diseases caused by DNA viruses
- Herpes
- Hep B
- Adenovirus
four problematic viral pathogens (examples of diseases)
- Herpes (HHV)
- Hepatitis A/B/C etc
- influenza
- retroviruses (HIV)
what are four common viruses in the herpes family
- HSV 1
- varicella
- Epstein Barr
- Cytomegalovirus
what three divisions make up the prokaryote category of infectious agents
- Eubacteria
- small bacteria with no cell wall
- obligate intracellular bacteria
which type of prokaryote is most commonly a pathogen (examples)
eubacteria (staph, strep, e coli)
what is an example of a small bacteria with no cell wall
mycoplasm
what are two examples of obligate intracellular bacteria
- chlamydia
- rickettsia
in what three ways are eubacteria classified
- gram stain
- general shape
- oxygen requirement
three common shapes of eubacteria
- cocci
- bacilli
- spirochetes
are most pathogenic bacteria aerobic or anaerobic?
what are two examples of disease processes caused by anaerobes
aerobic
abcesses or necrosis from clostridium
who invented the gram stain?
what does it do
hans christian gram
it stains bacterial cell walls accoring to their structure
why are some bacteria gram positive and some gram negative
gram positve bacteria have a thick layer of peptidoglycan in their cell wall that holds crystal violet dye
gram negative have less peptidogylcan as well as an outer membrane that slows down dye absorption
three examples of pathogen gram positive cocci
- staph aureus
- strep pyogenes
- entercoccus faecalis
three examples of gram positve pathogen bacilli
- bacillus anthracis
- corynebacterium diphtheriae
- clostridium species
two examples of gram negative pathogens
- neisseria gonorrhoeae
- neisseria meningitides
three examples of gram negative bacilli
- E coli
- salmonella enterica
- klebsiella pneumonae
two common origins of infection
- comminty aquired infections
- hospital acquired infections
example of a pathogenic spirochete
treponema pallidum
two examples of pathogenic mycobacterium
- mycobacterium tuberculosis
- mycobacterium leprae
what does an acid fast stain do
removes the outer coating of mycolic acid from mycobacterium so they can be stained
how is tuberculosis usually introduced?
where does it intially cause symptoms
aerosol particles or ingestion of infected milk
pulmonary or GI, depending on route
T/F advanced TB can cause symptoms all over the body
true
what percent of TB strains are drug resistant
10-15%
T/F the mortality in multi-drug resistant TB is less than untreated TB due to treatment
false, resistant TB has a similar mortality rate despite treatment
two types of protist pathogenic parasites
protozoans and helminths
three common pathogenic protozoans
- giardia lambia
- trichomonas vaginalis
- plasmodium vivax
what protozans are vulnerable to treatment from metronidazole
- amoebic dysentery
- giardia dysentery
- trichmonas
what are two treatments for plasmodium infections
- chloroquine
- artemisinins
four common pathogenic fungi
- candida albicans
- pneumocystis jirovecii
- histoplasma capsulatum
- cryptococcus neoformans
what are four general pathologies associated with fungal infections (examples)
- skin infections
- pulmonary infections (pneumonia)
- CNS infections (meningitis, encephalitis)
- systemic
common defintion of antibiotics
any substance that kills or inhibits the growth of other microorganisms
what are two other uses for antibiotics
- cancer chemotherapy
- immune modulators
four methods of antibiotic action
- cell wall inhibitors
- inhibition of protein synthesis
- inhibition of nucleic acid synthesis
- inhibitors of folate biosynthesis
what are three antibiotics that inhibit cell wall formation
- penicillin
- cephalosporins
- vancomycin
three antibiotic inhibitors of protein synthesis (example)
- tetracylines (tetracyline)
- macrolides (erythromycin)
- aminoglycosides (gentamycin)
what class of antibiotic inhibits nucleic acid synthesis (example)
fluoroquinolones (cirpofloxacin)
what is a class of antibiotic that inhibits folate biosynthesis (example)
sulfa (sulfonamide)
T/F 20% of all bacteria causing hospital acquired infections are resistant to 1 or more antibiotic
false, >70%
what type of infection is MRSA a common acronym for?
what would be a more appropriate title?
methicillin resistant staph aureus
multiple resistant staph aureus
statistically, why is MRSA more serious that normal staph?
- 3x longer hosptial stay
- 3x cost of stay
- 5x increased mortality
what four ways providers and patients have encouraged antibiotic resistance
- improper treatment
- improper dose or duration
- reliance on chemotherapy
- improper utilization of cultures and sensitivities
how would a reliance on chemotherapy increase antibiotic resistance
relying on drugs to fight infections caused by abcesses or necrosis rather than removing the infectious material increases the length of treatment
three drugs that are useful to treat herpes
- acyclovir
- famciclovir
- valaciclovir
what are two effect drugs in treating hepatitis
- interferon
- ribavirin
what are two drugs that are used to provide prophylactic treatment for the flu
- amantadine
- rimantadine
what type of drugs are zanamivir and oseltamivir?
what are they used to treat
neuraminidase inbihitor antivirals
influenza
six categories of drugs used to fight HIV
- nucleoside reverse transcriptase inhibitors
- nucleotide inhibitors
- non-nucleotide reverse transcriptase inhibitors
- protease inhibitors
- fusion inhibitors
- integrase inhibitors
two drugs used to fight systemic anti fungal infections
- amphotericin B
- fluconazole
two drugs used to treat superficial fungal infections
- miconazole
- clotrimazole
