Virology and antimicrobials

ok

because bacteria reproduce asexually, they must obtain new genetic info using different mechanisms than organisms that reproduce secularly

transduction

a process that involves bacteriophages. bacterial DNA are CARRIED ACROSS from one cell to another by a bacterial virus (typically occurs after one cell is infected by a temperate phage)

eukaryotic toxic antifungal

because fungi cells are ___________, they are more difficult to control. drugs used to control these organisms are typically ________ to the host. the mechanisms of __________ drugs is to bind with cell membrane sterols or cell wall (fungal membranes contain ergosterol)

true

animals obtain folic acid from the diet, therefore animal cells are not affected by sulfa drugs

anti parasitic

parasites can be quite toxic to the host, ________ agents typically interfere with nucleic acid synthesis or various metabolic pathways . if the parasite is not in the blood or gut, they are difficult to treat with drugs

synthesis positive

penicillin inhibits cell wall __________ destroying gram ______ bacteria (streptococci and staphylococci)

neurodegenerative kuru

prions are responsible for ___________ disease: 1. animal disease: --Scrapie in sheep --Mad cow disease in cattle --chronic wasting disease in Cervids 2. Human disease: --K____ --Creutzefelt-Jakob

lysogenic conversion expressed trait

prophage can confer new properties on the cell. phage DNA not completely suppressed --genes coding for trait are __________ ----organism displays new ______ ----------ex: streptococcus pyogenes manufactures toxin resulting in scarlet fever due to lysogenic conversion

lysogeny

replication of a temperate virus (this is a non-productive cycle)

intrinsic resistance

resistance due to inherent characteristics of the organism

bacteriostatic

sulfonamide drugs (sulfa) are ____________ -they inhibit bacterial growth -do not kill directly

lysogeny prophage

temperate phages inject their DNA into the cell it is incorporated into the bacterial chromosome ---does not immediately cause a lytic cycle ---L________ the phage is now referred to as a _________ ---consist only of DNA at this point

competitive

the sulfonamide molecule is similar in shape to p-aminobenzoic acid (PABA) --a precursor to folic acid --enzymes that convert PABA to folic acid don't convert sulfonamides to folic acid 2. these drugs act as ______________ inhibitors ---they compete with an enzyme required to produce essential antibodies

penetration

this phase of the lytic cycle is entrance of the virus OR its nucleic acid in the host cell ---plant and bacteria viruses inject the nucleic acid into the host through the cell wall

assembly

this phase of the lytic cycle is the assembling of the replicated viral components into an intact mature virion

absorption

this phase of the lytic cycle is where the page attach to specific receptor on the cell wall of E coli

acute infections

this type of infection Is usually short in duration, the host may develop a long lasting immunity, results in productive infection (produce large number of viruses during replication), and disease symptoms results from tissue damage and infection of new cells

persistent infections latent infection chronic infection slow infection

this type of infection is when viruses continually present in hosts 3 categories are

penicillinases cephalosporinases carbapenemases

three types of b-lactamases

Nucleocapsid

complete complex of nucleic acid and protein packaged in the virion

absorption penetration incorporation

lysogeny begins like the lytic cycle: API

nonliving

viruses, viroids and prions are _________ elements (acellular)

head

1

penicillins cephalosporins carbapenems tetracyclines aminoglycosides macrolides fluoroquinolones

1. P_________: bactericidal; interfere with cell wall synthesis) 2. C_________: bactericidal; interfere with cell wall synthesis) 3.C_________: bactericidal; interfere with cell wall synthesis 4. T_________: bacteriostatic; inhibit protein synthesis 5. A_________: bactericidal; inhibit protein synthesis 6. M_________: bacteriostatic at lower doses; bactericidal at higher doses; inhibit protein synthesis 7. F_________: bactericidal inhibit DNA synthesis

repressor host exit lytic

1. once incorporated, __________ genes are expressed and repressor proteins are produced (these hide or suppress the viral genome from host immune responses ) 2. the viral DNA is replicated only when the ________ cell replicates (this allows for a population of infected cells that carry virus genome) 3. virion can eventually _______ the host chromosome and return to the _________ cycle

productive lytic latent lysogenic

1. some virions multiply inside the cell producing numerous progeny. --term ___________ cycle -----__________ cycle: phage lyse infected cell 2. some integrate into host genome --termed ________ cycle -----__________ state

sheath

2

virulent phages temperate phages

2 categories of bacteriophages

naked enveloped

2 types of virion: 1. _______- without envelope 2. _________: surrounded by lipid membrane

tail

3

isometric helical complex

3 different shapes of viruses

tail fiber

4

end plate

5

DNA RNA without mitosis energy protein nucleic acid

5 properties that distinguish viruses: 1. posses either _______ or _______ but NOT both 2. unable to reproduce __________ a host cell 3. no __________ or meiosis 4. lack the competes necessary for __________ production 5. depend on host products and organelles for _________ and __________ _______ production

protein coat

6

DNA

7

core

8

phagocytosis fusion viruses

Animal viruses during penetration enter the cell whole: 1. animal cells have no rigid cell wall 2. penetration of virus is through --___________ in which the virus is engulfed by the cell --membrane ___________ occurs with enveloped viruses when the viral envelope fuses with the plasma membrane of the host cell -- ___________ enter intact but require an uncaring step to releases the nucleic acid form the protein coat

bacteriostatic

Ideally, only persons with healthy active immune systems should receive __________ agents as these drugs rely on the host immune system to destroy bacteria

inhibit proteins nucleic acid replication

Lytic Cycle: during transcription/replication: 1. viruses __________ activity of the host DNA 2. viruses produces enzymes to destroy host DNA 3. viral DNA takes over and begins producing _________ --early viral proteins are synthesized and associated with the replication of viral _________ _______ --late viral proteins are synthesized and are associated with the __________ of other viral structures

multiple drug resistance organisms

MDROs (superbugs)

extracellular intracellular

Viral Replication cycle: 1. Only multiply inside metabolizing cell (uses host machinery) 2. every virus contains info to make viral proteins, assure replication and move in and out of host cells 3. viruses exist in two phases: --____________ phases: metabolically inert --___________ phase: metabolically active

linear circular single double

Viral genome: 1. contains only single type of nucleic acid (either DNA or RNA; NEVER both) 2.can be _________ or __________ (usually circular) 3. _______ or ________ stranded

sulfonamide

____________ drugs inhibit production of folic acid (some bacteria need folic acid to produce essential proteins)

reproduction virion protein lysis outside transmission

acute infections: 1. reproductive cycle of animal virus can be competed to virulent bacteriophage 2. essential steps in include: -attachment -entry into susceptible cell -targeting site of __________ -uncoating a _______ (removing protein coat exposing Nucleic acid) -replication of nucleic acid and synthesis of __________ -maturation -cell _________ -spreading within host -shedding _________ host -__________ to new host

viruses kill

all forms of life can be infected by _________. viruses frequently ______ host cells (some live harmoniously with host)

pathogens damage allergic resistant

an ideal antimicrobial has the following: 1. kill or inhibit _________ 2. cause no __________ to the host 3. cause no _________ reactions 4. remain stable when stored 5. remain stable in vivio 6. kill all of the pathogens before they can mature and become ________

immunocopromised

antibacterial agents should not be used in ____________ patients and antibacterial agents that target virulence factors such as toxins and enzymes are in development

antiviral agents

antibiotics are NOT effective against viral infections. These agents are drugs used to treat viral infections and interfere with virus-specific enzymes and virus production by disrupting critical phases in viral multiplication or inhibiting synthesis of viral DNA, RNA or proteins

broad spectrum

antibiotics that impact both gram positive and gram negative cells are considered ________ ________ antibiotics

cocktails

antiviral agents can be delivered as "__________"

acquired resistance

bacterial resistance to a drug to which they were previously sensitive

viruses, viroids, prions

called agents or particles, not organisms, usually consist of only a few molecules that are found in living cells

oncoviruses uncontrolled

cancers caused by DNA viruses results from integration of vial genome onto host DNA -____________ or oncogenic viruses -transformed genes are expressed (__________ growth results)

genomic structure envelope

classification of animal viruses: 1. taxonomic criteria based on: --__________ structure: DNA or RNA, single or double stranded --virus particle __________: isometric, pleomorphic, helical --presence or absence of ________

b lactam

double ring structure found in penicillins and cephalosporins

tumors lyse killing

double stranded DNA viruses are responsible for most viruses induced ________ in humans: --these viruses interact with oct cells in one of two ways: 1. virus can go through productive cycle and ______ cell 2. virus can transform cell without _______ it

double stranded DNA single stranded RNA single stranded DNA double stranded RNA

four categories based on genome type of viruses (last two are uncommon)

phenotype lysogenic conversion

however, the prophage genes can be expressed and their gene produced transcribed/translated 2. the bacterial cell now has not only a new genotype but also a new ___________ 3. a _______ ___________ has taken place 4. the bacterial cell has now been converted as a result of lysogeny and is now able to produce new gene products

latent infections

infection is followed by symptomless period then reactivation. infection particles are not detected until reactivation. symptoms of reactivation and initial disease may differ (herpes simplex viruses and shingles)

slow infections

infectious agent gradually increases in amount over long period of time (no significant symptoms apparent during this time). two groups of infectious agents causes these: retroviruses which includes HIV

chronic infections

infectious viruses can be detected at all times. disease may be present or absent during extended times or may develop late. example HEP B

narrow spectrum

inhibiting one specific step in a metabolic pathway that produces some essential product is enough to cause cell destruction. antibiotics that only impact a specific class of bacteria, such as gram positive or gram negative cells are considered _______ _______ antibiotics

b- lactamases

some bacteria produce enzymes ___-__________, that destroy these rings thus making drugs ineffective

synthesis membranes synthesis synthesis enzyme

the 5 most common mechanisms of action for antimicrobial: 1. inhibition of cell wall ___________ 2. damage to cell ___________ 3. inhibition of nucleic acid __________ 4. inhibition of protein __________ 5. inhibition of ___________ activity Must meet at least the first two characteristics for ideal antibiotic

absorption penetration biosynthesis assembly release

the five stages of the lytic cycle are (LAP BAR)

releases envelope

the host cell bursts and __________ viruses to the outside environment (viruses are now extracellular) 2. in membrane bound viruses, as viruses leave the host cell, the ____________ is picked up ---the (_____) is made of a portion of the host cell plasma membrane which becomes the lipid envelope of the virus

lysogenic normal

the infected bacterial cell is now a ___________ cell, the phage DNA is replicated with each bacterial replication/binary fission even (daughter cells are also lysogenic) 2. under ________ conditions, the prophage does not cause the lytic cycle to occur

ok

the prophage may begin to produce phage DNA and proteins when certain stimuli are present (energy heat chemical signals)

capsid capsomers

the protein coat is termed __________; which is composed of ________ or capsomeres

lysogenic conversion transduction transformation conjugation

there are at least 4 ways other than mutation through which bacteria acquire new genetic material

prions

these are infections proteins and contain NO nucleic acid

viroids

these are simpler and smaller than viruses and still require a host cell for replication

viruses

these can contain a protein coat surrounding nucleic acid (genome); essentially a protein bag of nucleic acid

sexually transmitted viruses

this disease causing virus can cause lesions on genitalia or cause systemic infections

enteric viruses

this disease causing viruses is generally transmitted via fecal-oral route, causes gastroenteritis, some can cause systemic disease

respiratory viruses

this disease causing viruses is usually inhaled via infected respiratory droplets, generally remain localized in respiratory tract

zoonotic virus

this disease causing viruses transmitted from non-human animal to human via animal vector

penicillin

this drug interferes with the synthesis and cross linking of peptidoglycan

incorporation prophage

this phase of lysogeny is viral nucleic acid incorporates onto the host chromosome --this virus is called a __________ or provirus

bacteriophage

viral types: 1. animal viruses 2. plant viruses 3. fungal viruses 4. bacterial viruses ---____________

nucleic acid protein coat

virions consist of _______ _______ surround by a ______ ________

RNA plant

viroids consist of a single short piece of _______, contain no protective protein coat and generally causes ________ diseases

adsorption penetration uncoating biosynthesis assembly release

virulent phages always cause the lytic cycle to occur

virion

virus particle is called

nonliving organsims domain infect

viruses are __________ entities, not considered o___________, can infect organisms of every __________, commonly referred to by the organism they _________

capsid capsomeres envelope infect

viruses are classified by: 1. type of genetic material (DNA or RNA) 2. shape and size of _________ 3. number of ____________ 4. presence or absence of an ___________ 5. type of host it i_________ 6. disease it produces 7. target cell 8. immunologic/antigenic properties

intracellular parasites replicate outside

viruses are termed obligate i_________ p_________. -they must have a host cell machinery to __________ - inactive _________ of host