Exam Two - notes

chapters 13, 14, 15, 16, 17

obligatory Intracellular Parasites require what to multiply

a living host cell

* there are some bacteria such as chlamydia and rickettsia that require living host to multiply

why do doctors sometimes give us antibiotics when we have a different infection"?

to treat possible secondary infections

* hospital settings are teeming with microbes, so just being there with a weakened immune system makes us susceptible to other infections, so they preemptively give us antibiotics to treat them

True or False: viruses DO NOT posses both DNA and RNA

TRUE

general characteristics of Viruses

* obligatory Intracellular Parasites
* contain DNA OR RNA
* contain a protein coat
* they have No Ribosomes
* they have no ATP

host range

the spectrum of host cells a virus can infect; determined by specific host attachment sites and cellular factors

bacteriophages are…

viruses that infect bacteria

virion

complete, fully developed viral particle

* nucleic acid
* capsid
* envelope
* spikes

capsid

protein coat made of capsomeres (subunits)

spikes

projections from outer surface

what is the very FIRST thing a pathogenic organism must do?

attach

Due to the fact that we cannot grow a virus itself in order to observe its metabolic pathways or other characteristics, what must we do?

we can look at what they infect and learn things about them that way

viroid

composed solely of a short strand of circular, single-stranded RNA that has no protein coating

* the smallest infectious pathogens known

viral species

a group of viruses sharing the same genetic information and ecological niche (host)

* descriptive common names are used for species
* subspecies are designated by a number

bacteriophages form BLANK

plaques- clearings on a lawn of bacteria on the surface of agar

how can we grow animal viruses in a lab?

in living animals, in embryonated eggs, in cell structures

when growing animal viruses in embryonated eggs, how do we know if there is viral growth?

by changes or death of the embryo

with animal viruses growing in cell structures, how are they detected?

via their deterioration, or cytopathic effect (CPE)

* they make the stuff inside the host cell divide over and over again, until it bursts, spreading the Virus

one-step growth curve

the top is where we either die or defeat the virus

steps of the lytic cycle (multiplication of bacteriophages)

* attachment
* penetration- phages lysozyme opens the cell wall; the tail sheath contracts to force the tail core and DNA into the cell
* biosynthesis
* maturation
* release

TRUE or FALSE bacteriophages never actually enter the cell, but instead inject the information

TRUE

animal viruses are pulled in the cell by what mechanisms?

endocytosis

lysogenic Cycle (multiplication of bacteriophages)

* attachment
* entry
* integration
* cell division

phage conversion

when the DNA of the bacteriophage Becomes Part of the Host DNA

* we are pretty sure that the majority of our DNA is from various viruses because of being infected over time

steps for multiplication of Animal Viruses

* attachment
* entry by receptor- by endocytosis or fusion
* uncoating
* biosynthesis
* maturation
* release by budding

poxviridae

* DNA virus
* double-stranded DNA, enveloped
* causes skin lesion
* ex. vaccinia and smallpox

Herpesviridae

* double-stranded DNA virus, enveloped
* HHV-1 and 2
* HHV-3
* HHV-4
* HHV-5
* HHV-6
* HHV-8

HHV-1 and HHV-2

simplexviruse; causes cold sores

HHV-3

causes chickenpox and shingles

HHV-5

ctyomegalovirus; important for OBGYN and PEDS

* torch test for different viruses and infections

papovaviridae

* double-stranded, NON-enveloped
* papillomavirus- causes warts and HPV

hepadnaviridae

uses reverse transcriptase to make DNA from RNA

rhinovirus

common cold

lyssavirus

rabies; a bullet-shaped virus

retroviridae

lentivirus (HIV)

* RNA virus that use DNA via reverse transcriptase

sarcoma

cancer of connective tissue

oncogenes

transform normal cells into cancerous cells, if anything goes wrong with them in any way, a cancer state in the cell occurs

why cant we just Cure Cancer?

there are 217 different types of cancer because we have so many different tissue types in our bodies; melanomas tend to be very aggressive while nerve cell cancers are extremely slow

latent viruses

remain asymptomatic for long periods

may reactivate due to changes in immunity

persistent viral infection

occurs gradually over long periods and is generally fatal

prions

infectious proteins

etiology

the cause of a disease

pathogenesis

the development of disease

infection

invasion or colonization of a body by pathogens

disease

an abnormal state in which the body is not performing normal function

transient microbiota

may be present for days, weeks, or months

areas of normal microbiota

skin, eyes, nose and throat, mouth, large intestine, urinary and reproductive systems

skin microbiota

gram-positive

acinetobacter

candita-fungal (yeast)

eye (conjunctiva) microbiota

tears and blinking also eliminate some microbes or inhibit others from colonizing

nose and throat microbiota

gram-positive

nasal secretions kill or inhibit many microbes, and mucus and ciliary action remove many microbes

symbiosis

the relationship between normal microbiota and the host

* commensalism & mutualism

Koch’s Postulates exceptions

some pathogens can cause several disease conditions

some pathogens cause disease only in humans (we cant exactly inject people with a virus and see what happens)

some microbes have never been cultured

symptoms

changes in body function that are felt by a patient as a result of disease

* subjective
* like a pain scale

signs

changes in the body that can be measures or observed as a result of a disease

syndrome

a specific group of signs AND symptoms that accompany a disease

communicable disease

a disease that is spread from one host to another

contagious disease

diseases that are easily and rapidly spread from one host to another

noncommunicable disease

a disease that is not spread from one host to another

incidence

number of people who develop a disease during a particular time period

* number is important here
* they take a snapshot of the number infected week to week for example and determine spread, only looking at new data and disregarding old

prevalence

number of people who develop a disease at a specific time, regardless of when it first appeared

* takes in to account new and old cases

sporadic disease

a disease that occurs only occasionally

* every once in a while
* like the flu

endemic disease

disease constantly present in a population

* in a certain area that is always present
* the bubonic plague in the US (Arizona)

epidemic disease

a disease acquired by many people in a given area in a short time

* when the endemic level goes above baseline

pandemic disease

worldwide epidemic

acute disease

symptoms develop rapidly but the disease lasts only a short time

chronic disease

symptoms develop slowly

subacute disease

intermediate between acute and chronic

latent disease

causative agent is inactive for a time but then activates and produces symptoms

herd immunity

immunity on most of the population

* what we could have if people weren’t selfish and stupid

\

focal infection

systemic infection that began as a local infection

sepsis

toxic inflammatory condition rising from the spread of microbes, especially bacteria or their toxins, from a focus of infection

bacteremia

bacteria in the blood

* the bacteria is just kinda there, floating around

septicemia

also know as blood poisoning; growth of bacteria in the blood

* the bacteria are actually doing something

secondary infection

opportunistic infection after a primary infection

* why we give antibiotics to prevent the secondary infection (not so much anymore)

subclinical disease

no noticeable signs or symptoms

* the problem with a lot of diseases is that they dont know they have and are just spreading the infection

development of disease

* incubation period


* prodromal period
* period of illness
* period of decline
* period of convalescence

incubation period

the interval between initial infection and first signs and symptoms

prodromal period

short period after incubation; early and mild symptoms

period of illness

when the disease is most severe

period of decline

when signs and symptoms subside

period of convalescence

when the body returns to its pre-diseased state

fomite

nonliving object that can be used as a means to spread disease

* doorknob that an infected person touches

vectors

arthropods; fleas, ticks, and mosquitoes

* mechanical transmission
* biological transmission

contributing factors to emerging infectious diseases

* genetic recombination
* evolution of new strains
* widespread use of antibiotics and pesticides
* changes in weather patterns
* modern transportation
* ecological disasters, war, and expanding human settlement
* animal control measures
* public health failure

epidemiology

the study of where and when diseases occur and how they are transmitted in populations

CDC roles and measurements

collects and analyzes epidemiological information in the US

publishes morbidity and mortality weekly report (MMWR)

* morbidity
* mortality
* notifiable infectious diseases
* morbidity rate
* mortality rate

morbidity

incidence of a specific notifiable disease

mortality

deaths from notifiable disease

notifiable infectious diseases

diseases in which physicians are required to report occurrence

morbidity rate

number of people affected in relation to the total population in a given time period

mortality rate

number of deaths from a disease in relation to the population in a given time period

virulence

the degree of pathogenicity

TRUE or FALSE: doctors don’t need to report certain diseases to the CDC

FALSE

portals of entry

mucous membranes

* resp. tract
* GI tract
* genitourinary tract
* placenta

conjunctiva of the eye

parental route (other than the alimentary canal)

* broken skin
* bites
* injection
* puncture

alimentary canal

digestive tract

TRUE or FALSE: endospores, which enter through the skin, are the most virulent form of anthrax

TRUE

TRUE or FALSE: botulinum is so potent that only 0.03 ng/kg is a lethal dose

TRUE

how do pathogens penetrate Host defenses?

* capsules to impair phagocytosis
* cell wall components such as M proteins, Opa proteins, and waxy lipids
* enzymes
* coagulation
* kinases
* hyaluronidase
* collagenase
* IgA proteases

strep pyogenes use what to resist phagocytosis

M proteins

neisseria gonorrhea use opa proteins which allow them to..

attach to host cells

which disease uses a waxy lipid (mycolic acid) to resist digestion?

mycobacterium tuberculosis