Microbiology Exam 4

Chemical Additives

-can prevent growth of microbes -toxicity a concern

The viral genome is protected from the environment by a protein shell called:

Capsid

an example of lysogenic conversion

a lysogen that acquires a new characteristic as a result of prophage

A virus usually only infects certain types of cells due to

interactions between viral and cellular surface molecules

Ultra high temperature method

involves a high temperature for short time. can be stored at room temp

decontamination

mechanical removal of most microbes from living or inanimate surfaces

culture media milk destroy microbes by

moist heat

broad spectrum microbial disadvantage

more likely to disrupt the normal microbiota that play an important role in excluding pathogens

Productive infection

new viral particles are produced

what is used to classify viruses

nucleic acid shape size host range

Viral animal infection that continue with or without symptoms for years

persistent infection

Latent state

viral genome remains silent within the cell

Antiseptic

antimicrobial chemical that is non toxic enough to be used on skin

the best definition of antibiotics is

antimicrobial drugs naturally produced by microorganisms

The binding of a bacteriophage surface protein to a host cell receptor is called:

attachment

sterilization

destruction of all microbial life

taking an antimicrobial can lead to an imbalance in the microbiome called

dysbiosis

Disinfection

elimination of most or all pathogens on or in a material

In a lysogenized bacterium, _______ of the prophage results in a lytic infection

excision

which steps must be taken to prevent the spread of antimicrobial resistance

general public / physicians must take responsibility for the use of medications countries must make important policy regarding responsibility of medications

the result of packaging errors during the assembly stage of phage replication

generalized transduction

Symptoms of acute viral diseases result from

host immune response host tissue damage

Possible hosts of prions

humans cattle sheep goats deer elk

What are the effects of increasing the pressure of water in an autoclave?

increases the temperature at which steam forms increases the boiling point of water

Which of the following directs incorporation of phage DNA into a bacterial chromosome:

integrase

Some bacteria produce toxins that are encoded on prophage DNA This is an example of ______conversion

lysogenic

: a change in the phenotype of a lysogen as a consequence of the specific prophage it carries

lysogenic conversion

in enveloped viruses sandwiched between the nucleocapsid and the envelope is the

matrix protein

antiviral medications that interfere with viral nucleic acid synthesis often appear very similar to which compound?

nucleosides

Chronic and latent infections are classified as

persistent infections

meat products heat sensitive medication destroy microbes by

radiation

disinfection

reduction of most microbial life on inanimate surfaces

To maintain a lysogenic state a ( _____ ) protein prevents expression of the gene required for excission

repressor

A process that substantially reduces the number of microbes to meet accepted health standards but doesnt indicate any specific level of control is called:

sanitization

preservation

slows microbrial growth but does not reduce the number of living microbes

what are the two types of transduction?

specialized and generalized

in specialized transduction

specific dna is transferred

malignant

spreads to nearby tissue

an item that is free of all viable microbes, including endospores is called

sterile

Phage DNA and proteins are made during which stage of the T4 lytic cycle

synthesis

an infectious agent that lacks a capsid and consists only of RNA

Viroid

T/F Lysogens are more susceptible to reinfection by the same type of phage

False

Soap generally does not destroy most microbes but aids in their:

Mechanical Removal

Enveloped virus can gain entry into animal cells by

endocytosis of the virus by the host cell fusion of the viral envelope and the cell membrane

The mechanism of exit for an animal virus is primarily determined by whether or not the virus has a(n) ____

envelope

consequences of lysogeny include

immunity to superinfection lysogenic conversion

physical ways to remove or destroy microbes

incineration filteration auto claving ultra violet radiation

Which of the following infections are analogous to lysogenic infections by bacteriophages in that they involve a viral genome that is silent in the host cell

latent

narrow spectrum advantage

less likely to disrupt the normal microbiota

This term is used to describe the rupture or bursting of a cell

lyse

scientists are scrambling to invent new antimicrobial medications because

many microorganisms have developed resistance to the ones currently available

Heat treatment

most common and reliable but can alter flavor and appearance of product

High temperature short time method

most commonly used products still require refrigeration or freezing

Because they are dependent on host cells viruses are classified as

obligate intracellular parasites

a strong but unstable oxidizing agent must be generated on size used as an alternative to chlorine

ozone

when selecting an appropriate chemical disinfectant it is important to realize that the death rate is significantly influenced by

pH Temperature

brief heat treatment used on food items to kill potential agents of spoilage without significantly altering food quality

pasteurization

Viruses that infect bacteria are called

phages bacteriophages

Phage DNA that is latently incorporated into the bacterial host genome is called a _______

prophage

the role of surface proteins or spikes

provide means of attachment to host cell surface

when certain bacteria are said to have intrinsic (innate) resistance , this means they have

some inherent property that makes them generally more resistant to the effect of some antimicrobials

the result of excision errors made as temperate phages transition from a lysogenic to a lytic cycle

specialized transduction

enveloped viruses can derive their envelopes from

the host cytoplasmic membrane certain host organelles

Which statement regarding viruses are true? -viruses that infect bacteria can be called phages -the terms virus and phage are interchangeable -some viruses can infect prokaryatic and eukaryotic cells -viruses that infect bacteria can be called bacteriophages

-viruses that infect bacteria can be called phages -viruses that infect bacteria can be called bacteriophages

What is the order of animal replication

Attachment to host cell surface Penetration and uncoating Synthesis Assembly Release from host cell

it is important to minimize the number of pathogens in healthcare settings due to the risk of

Healthcare associated infections

Transmissible Spongiform Encephalopathies are caused by

prions

narrow spectrum disadvantage

the pathogen must be identified

destroys acellular infectious agents

virucides

explains how an antibiotic that inhibits protein synthesis can be selective.

Antibiotics bind to the 70S bacterial ribosomes but not to the 80S eukaryotic ribosomes

Chemicals used to decrease the number os microbes on living tissues

Antiseptics

Which organisms can be destroyed by extreme heat

Bacterial endospores, protozoan cyst and oocyst.

used to destroy microbes on inanimate (non living objects)

Disinfectants

Potentially harmful chemicals that form when chlorine and other disinfectants react with other chemicals in the water are called

Disinfection by-products

Describe a latent infection

Long periods of time with essentially zero viral replication, punctuated by outbreaks of active replication and disease manifestation. Infected individuals are largely non-infectious between outbreak periods.

Describe three groups of organisms that are resistant to certain chemical treatments.

Mycobacterium, Pseudomonas, Non Enveloped

Heat treatment, filtration, radiation are examples of what kind of microbial growth control

Physical method

A bacterium being examined in a microbiology laboratory is found to be lysogenized by phage A.

The bacterium exhibits a new genotype but may not exhibit a new phenotype.

How would a company that makes lipstick determine if a batch had been contaminated by microbes during the production process?

They would have to test for contamination in a lab, generally tested and approved by the FDA before dispersal.

selective toxicity

This term is used to describe compounds that cause greater harm to microbes than to the human host.

antimicrobial action

This term is used to describe the molecular method by which a compound might kill or inhibit a microbe.

spectrum of activity

This term is used to describe the range of different microbes that a compound can kill or inhibit.

Will an operating room be sterilized between patients? Explain.

Yes; because each room has to be sterilized and cleaned to ensure the previous patients infections don't transfer.

To ensure that an autoclave is properly sterilizing it is important to use

a biological indicator

when a previously sensitive organism develops resistance through spontaneous mutation or horizontal gene transfer this is an example of

acquired resistance

commercial canning also destroys

all other organisms that grow under normal storage conditions

the following use moist heat to destroy microbes

boiling pasteurization pressurized steam

C. Diff associated disease is caused by

broad spectrum antibiotics inhibiting or killing members of the normal microbiota allowing c. diff to flourish

irradiation and high pressure

can destroy microbes without altering the product

Expression of viral oncogenes in infected animal cells

can mimic proto-oncogenes, causing imbalance in cell cycle control towards unchecked proliferation, leading to tumor formation.

Antimicrobial Chemical is an example of what kind of microbial growth control

chemical method

it is important to destroy all endospores of clostridium botulinum in commercial canning because

the spores can germinate in canned foods and vegetative cells can produce botulinum toxin

The reasons sugar or salt can be used for preservations

they create a hypertonic environment they dehydrate bacterial cells may cause plasmolysis

an antimicrobial medication is a chemical used to

treat an infectious disease

The process by which the viral nucleic acid is released from the protective protein coat is called:

uncoating

Broad spectrum microbial advantage

useful for treating acute life threatening diseases when immediate antimicrobial therapy is needed and there is no time to culture and identify the pathogen

before enveloped viruses can bud from a host cell specific viral proteins insert into the host membrane. these proteins become

viral spikes

Which contain only one type of macromolecule

RNA DNA Prions

Compare and contrast the methods used to control microbial growth in daily life, healthcare settings, micro labs, food and food production facilities, water treatment facilities, and other industries.

a. Daily life includes using soaps and detergents but not actually destroying any microbes or pathogens just moving them. Cooking foods, cleaning surfaces and refrigeration are also methods. b. Health care facilities must sterilize every object before performing any surgeries. c. Micro Labs- Must sterilize everything just like health care facilities but they also perform Aseptic technique to ensure there is no contamination from the environment. d. Food and food product facilities Use heat treatment, they also do surface cleanings like daily life. e. Water treatment facilities use chlorine

Explain the principles of sterilization, disinfection, pasteurization, decontamination, sanitization, and preservation.

a. Sterilization- Complete removal/destruction of viruses and microorganisms. b. Disinfection-Elimination of most pathogens. c. Pasteurization- A brief heat treatment for food items which reduces the # of spoilage and destroys pathogens. d. Sanitization- Bringing the amount of microbes down to a safe level and decrease disease spread. e. Preservation- Delaying aging of perishable foods.

Viral animal infection characterized by the sudden onset of a relatively short duration

acute infection

animal viruses can only be grown in

animal cells

combinations of antimicrobials are sometimes used to treat infections. a counteraction combination is called

antagonistic

The use of specific methods to prevent microbes from contaminating an environment is called :

aseptic technique

Virucide

chemical that inactivates viruses

Bacteriacide

chemical that kills bacteria

fungicide

chemical that kills fungi

Germicide

chemical that kills harmful microbes

EPA

chemicals used as pesticides

FDA

chemicals used to process medical devices

The hepatitis B virus sometimes causes an infection that results in a continuous and low level production of virus particles. This type of infection pattern is specifically described as

chronic viral infection

a chemical used to kill microbes on inanimate objects

disinfectant germicide

benign

does not spread to nearby tissue

medical waste inoculating loop animal carcasses destroy microbes by using

dry heat

To achieve equivalent microbial kill _____ heat must use longer exposure times and and higher temperatures than ____ heat

dry; moist

animal viruses that do not have a coating can only enter their host cell through

endocytosis