Bacteriophage Quiz

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Questions and Answers

What type of organism does a bacteriophage attack and reproduce inside?

Bacteria (correct)

Fungi

Humans

Plants

Who gets viral infections from bacteriophages?

Animals

Bacteria (correct)

Plants

Humans

Can humans get viral infections from bacteriophages?

It depends on the type of bacteriophage

No, only bacteria do (correct)

Yes, humans can get viral infections from bacteriophages

No, but animals can get viral infections from bacteriophages

What does a bacteriophage do during transduction?

Picks up bacterial genes and injects them into another bacterium Signup and view all the answers

How does a bacteriophage act during transduction?

As a carrier for bacterial DNA Signup and view all the answers

What is the role of a bacteriophage in transduction?

Acting as a vehicle for bacterial DNA transfer Signup and view all the answers

What is required for transduction to occur?

Donor and recipient bacteria, and a bacteriophage Signup and view all the answers

What type of genes does the bacteriophage have during transduction?

Genes from the previous bacterium Signup and view all the answers

What happens to the recipient bacteria during transduction?

They take up the 'new' DNA as their own DNA Signup and view all the answers

What happens to the donor bacterium in transduction?

It is completely lysed and killed by the bacteriophage Signup and view all the answers

What is the fate of the recipient bacterium during transduction?

It receives genetic material from the donor bacterium via the bacteriophage Signup and view all the answers

What are the main components of a bacteriophage's structure?

Protein shell and genetic material Signup and view all the answers

What role do viruses play in the ecology of Earth?

AB&C Signup and view all the answers

What is a significant function of viruses in genetic transfer?

They move DNA between species Signup and view all the answers

How do viruses impact populations of organisms?

They regulate vast populations of organisms Signup and view all the answers

What is necessary for viruses to enter cells?

Receptor molecule or molecules Signup and view all the answers

What is the primary requirement for viruses to infect cells?

Presence of compatible receptor sites Signup and view all the answers

What do viruses need in order to get into cells?

Receptor molecules that latch on to cells Signup and view all the answers

What did Mayer conclude is the cause of TMD?

A tiny infectious agent that cannot be seen with a microscope Signup and view all the answers

What is a characteristic of the infectious agent according to Mayer's work?

can't be seen under a microscope Signup and view all the answers

What did Mayer's work suggest about the size of the infectious agent?

It is too small to be seen with a microscope Signup and view all the answers

What did Mayer make a list of to investigate the tobacco problem?

Possible trouble-makers Signup and view all the answers

What was included in Mayer's list of possible trouble-makers?

Environmental soil conditions and pests Signup and view all the answers

What did Mayer suspect could be causing the tobacco problem?

Fungi and worms (all the above) Signup and view all the answers

What happened when Koch isolated bacteria on agar and injected it back into the cow?

The cow died Signup and view all the answers

What was the outcome when Mayer isolated plant bacteria on agar and put it on healthy plants?

The healthy plants lived Signup and view all the answers

What was the result of injecting bacteria isolated by Mayer back into healthy plants?

The healthy plants lived Signup and view all the answers

What was the outcome when Mayer put the TMD plant sap on healthy plants?

The healthy plants died Signup and view all the answers

What was the outcome when Koch put infected cow blood into healthy cows?

The healthy cows died Signup and view all the answers

What was one similarity between Mayer's and Koch's experiments?

Both resulted in the death of healthy organisms Signup and view all the answers

What is the causative agent for tobacco mosaic disease?

Tobacco Mosaic Virus Signup and view all the answers

Which type of organism is the causative agent for tobacco mosaic disease?

Virus Signup and view all the answers

What is the specific causative agent for tobacco mosaic disease?

Tobacco Mosaic Virus Signup and view all the answers

What would happen if TMD was caused by bacteria and alcohol was added to the sap?

The bacteria would be killed Signup and view all the answers

What effect would desiccating the bacteria have if TMD was caused by bacteria?

The bacteria would be killed Signup and view all the answers

What would boiling the sap do if TMD was caused by bacteria?

The bacteria would be killed Signup and view all the answers

What did Beijerinck conclude after his experiments failed to prevent the plant from TMD?

That Mayer was right the causative agent must be a virus Signup and view all the answers

What did Beijerinck's experiments fail to prevent the plant from?

Tobacco mosaic disease (TMD) Signup and view all the answers

What is the primary causative agent of osteomyelitis?

Staphylococcus aureus Signup and view all the answers

What happens to the infected bone in osteomyelitis?

It is a bone infection mostly caused by S. aureus and infected bone will de attach from healthy bone and form pockets of dead bone surrounded by dead tissue. Signup and view all the answers

Why is it hard to treat Osteomyelitis?

The body walls off the infected bone, making it difficult for antibiotics to reach the site Signup and view all the answers

What does the DTaP vaccine protect against?

Diphtheria, tetanus, and whooping cough Signup and view all the answers

Who is the DTaP vaccine intended for?

Children younger than 7 years old Signup and view all the answers

What type of pathogens are included in the DTaP vaccine?

Attenuated toxins and weakened pathogen Signup and view all the answers

What is the primary purpose of attenuation?

To weaken the pathogen so that it doesn’t cause disease but can still elicit antibody production Signup and view all the answers

What is the desired strength of an attenuated pathogen?

Strong enough to elicit antibody production but weak enough to not cause disease Signup and view all the answers

What is the causative agent of whooping cough?

Bordetella pertussis Signup and view all the answers

How is the bacterium Bordetella pertussis primarily spread?

By inhalation Signup and view all the answers

What type of bacterium is Bordetella pertussis?

Gram-negative rods Signup and view all the answers

What does Bordetella pertussis release that paralyzes the cilia?

Exotoxin Signup and view all the answers

When does Bordetella pertussis release its cytotracheal toxin?

Once quorum sensing has been met Signup and view all the answers

What type of toxin is released by Bordetella pertussis?

Cytotracheal toxin Signup and view all the answers

What is the role of the efflux pump protein in antibiotic resistance?

It pumps antibiotics out of the bacterial cell Signup and view all the answers

How are plasmid genes related to antibiotic resistance?

They can code for efflux pump proteins that pump antibiotics out of the cell Signup and view all the answers

Where does the efflux pump protein shown in the cell diagram reside?

Near the inner membrane of the cell Signup and view all the answers

What is the role of the efflux pump protein in antibiotic resistance?

It helps bacteria become resistant to certain antibiotics by pumping the antibiotics out of the cell Signup and view all the answers

How are plasmid genes related to antibiotic resistance?

They can code for proteins that confer antibiotic resistance and can be passed to new bacteria Signup and view all the answers

Where does the efflux pump protein reside in the cell?

Cell membrane Signup and view all the answers

What is the primary role of the new cell wall protein in the bacterium?

To help strengthen the cell wall Signup and view all the answers

What happens to the bacterium as a result of the new cell wall protein?

It becomes impermeable to certain antibiotics Signup and view all the answers

What is an important point to note about the new cell wall protein and antibiotic resistance?

The new cell wall protein has other purposes than antibiotic resistance Signup and view all the answers

How do antibiotics that affect bacterial ribosome affect the bacteria ?

By shutting down ribosomes and halting protein production Signup and view all the answers

What can lead to bacterial resistance to antibiotics targeting ribosomes?

Gene transfer resulting in slightly different-shaped ribosomal proteins Signup and view all the answers

What happens if antibiotics can no longer attach firmly to the ribosomes of a bacterium?

The ribosomes are not affected, and the bacterium becomes resistant to that antibiotic Signup and view all the answers

What is the primary cause of methicillin-resistant S. aureus (MRSA)?

Acquisition of a gene coding for the enzyme methicillinase Signup and view all the answers

What is the role of the enzyme penicillinase in Staphylococcus aureus?

It breaks down penicillin, conferring resistance to penicillin Signup and view all the answers

What does the term 'destruction' refer to in the context of antibiotic resistance?

The breakdown of antibiotic molecules by bacterial enzymes Signup and view all the answers

What is the gene that codes for an enzyme responsible for breaking down the beta-lactam ring in penicillin called? acquired through conjugation

Beta-lactamase Signup and view all the answers

What is the term used to describe Staph aureus that is resistant to methicillin?

MRSA Signup and view all the answers

What is the characteristic of wild type Staph aureus in relation to penicillin?

Very sensitive to penicillin Signup and view all the answers

What is the primary characteristic of plasmids?

Circular DNA separate from the main chromosome Signup and view all the answers

What is the essential nature of plasmids for an organism's life?

Non-essential, can be removed without affecting the organism Signup and view all the answers

Where are plasmids located within the cell?

Extrachromosomal, outside of the main chromosome Signup and view all the answers

What are the small and functional snippets of DNA called, discovered in 1959?

Plasmids Signup and view all the answers

Where are the genes transferred during bacterial conjugation located?

Small pieces of circular DNA in the cytoplasm Signup and view all the answers

When bacterial conjugation was first studied, the question was, “how does a donor bacterium just give up some of its genes to a recipient?” The donor bacterium does not die, so why would it give something up so important, what was discovered?

The transferred genes were not part of the large circular bacterial chromosome's DNA Signup and view all the answers

What is the process through which bacteria exchange small pieces of DNA through short 'tubes' or a much longer tube?

Conjugation ( see this in the wild more) Signup and view all the answers

What happens to the donor bacterium during conjugation?

It does not die Signup and view all the answers

What are the short 'tubes' called through which bacteria exchange DNA during conjugation ( see this in the wild more)?

Mating bridges Signup and view all the answers

What is the mechanism of DNA replication during conjugation?

Rolling-circle mechanism Signup and view all the answers

What happens to the plasmids in both bacteria during conjugation?

They replicate quickly to become identical in both bacteria Signup and view all the answers

How does DNA transfer occur during conjugation?

Through the formation of a conjugation tube Signup and view all the answers

What is a significant factor influencing the development of new strains and antibiotic resistance?

Horizontal gene transfer Signup and view all the answers

How does horizontal gene transfer contribute to antibiotic resistance in bacteria?

Facilitates exchange of antibiotic resistance genes Signup and view all the answers

What is necessary for bacterial transformation to occur?

Two closely related bacteria, one acting as the donor and the other as the recipient Signup and view all the answers

What is the outcome of bacterial transformation ( more in lab enivornment)?

It doesn't always make the bacteria pathogenic Signup and view all the answers

What was significant about Griffith's case?

It demonstrated an exception where transformation made the bacteria pathogenic Signup and view all the answers

What happens to the donor bacterium during transformation (more in lab environment)?

The donor dies Signup and view all the answers

How is DNA transferred during bacterial transformation?

DNA fragments bind to the recipient bacterium's DNA binding protein Signup and view all the answers

What is the fate of the recipient bacterium during transformation?

It remains unaffected Signup and view all the answers

What is a common occurrence in bacteria involving the acquisition of new genes?

Horizontal gene transfer Signup and view all the answers

How does a bacterium pass on its genetic material to daughter cells?

Vertical gene transfer Signup and view all the answers

What is the term for the regular parent cell passing on its genetic material to the daughter cells?

Vertical gene transfer Signup and view all the answers

What is the primary method through which our cells transfer genes?

Vertical gene transfer Signup and view all the answers

What is the term for the process through which bacteria exchange small pieces of DNA through short 'tubes' or a much longer tube?

Transduction Signup and view all the answers

What is the essential nature of plasmids for an organism's life?

They are non-essential but beneficial Signup and view all the answers

What is the genetic material that codes for proteins?

DNA contains genes which..... Signup and view all the answers

What are genes made of?

DNA Signup and view all the answers

In public health decisions, what does the 'vertical approach' refer to?

Targeting specific diseases Signup and view all the answers

What is the focus of the 'horizontal system' in public health decisions?

Supporting treatment and prevention for all health needs A and C Signup and view all the answers

What is a key consideration in public health decisions?

Balancing vertical and horizontal approaches Signup and view all the answers

What are the key factors involved in public health decisions?

Money, communication infrastructure, and management needs Signup and view all the answers

Why is the NTD horizontal approach not funded?

It is very expensive Signup and view all the answers

Why is malaria not considered 'neglected' despite being a tropical disease?

It receives a significant amount of funding Signup and view all the answers

What is a distinguishing factor that prevents malaria from being classified as a 'neglected' disease?

High investment in research and control measures Signup and view all the answers

What contributes to the non-neglected status of malaria despite being a tropical disease?

Considerable monetary allocation for addressing the disease Signup and view all the answers

What is the most common cause of illness among the poorest people in the LAC region?

Neglected Tropical Diseases (NTDs) Signup and view all the answers

Where do two-thirds of the region's poor live, contributing to the prevalence of NTDs?

Urban and suburban communities with unsafe water and poor sanitation Signup and view all the answers

What is a common situation faced by those living in rural poverty in the LAC region?

Living as subsistence farmers, ranchers, and fishermen Signup and view all the answers

What is a common characteristic of neglected tropical diseases (NTDs) mentioned in the text?

High disease burden, but low mortality Signup and view all the answers

What is a key factor contributing to the prevalence of NTDs, as per the text?

Rural poverty Signup and view all the answers

What is a distinguishing feature of leprosy, based on the text?

Causative agent is Mycobacterium leprae Signup and view all the answers

What is the prevalence of the diseases mentioned in the text?

1 in 10 Signup and view all the answers

What is a characteristic of the mentioned diseases regarding mortality?

High disease burden with low mortality Signup and view all the answers

What is a common feature of patients with the mentioned diseases?

Many patients have more than one NTD (chronic and for life) Signup and view all the answers

What diseases does the MMR vaccine target?

Mumps, measles, rubella Signup and view all the answers

How many diseases does the MMR vaccine target?

Three Signup and view all the answers

What is required after receiving the MMR vaccine?

Booster shots Signup and view all the answers

Which diseases does the MMR vaccine target?

Measles, Mumps, Rubella Signup and view all the answers

How are the three diseases targeted by the MMR vaccine primarily spread?

Through inhalation Signup and view all the answers

Which disease is referred to as 'hard measles' in the text?

Rubella Signup and view all the answers

What is the effect of measles infections on unvaccinated children, based on the studies?

Measles infections wipe out immune memories of other pathogens Signup and view all the answers

What risk do unvaccinated children face due to measles infections, according to the text?

Increased risk of other deadly diseases Signup and view all the answers

What is the overall impact of measles infections on the immune system of unvaccinated children?

Weakening of the immune system Signup and view all the answers

Where can the mumps virus be found even after recovery?

Testes of males and ovaries of females Signup and view all the answers

Vaccinations developed because the mumps virus has been found in the ... ?

Testes of males Signup and view all the answers

What is the causative agent of Rubella?

Rubella virus Signup and view all the answers

Which disease is known as 'German measles'?

Rubella Signup and view all the answers

What is another name for Rubeola virus?

Hard measles virus Signup and view all the answers

Why would you need a vaccine for hard measles?

To prevent encephalitis, blindness, hearing loss, and cognitive problems Signup and view all the answers

Why would you need a vaccine for rubella or German measles?

To prevent birth defects as it can cross through the placenta Signup and view all the answers

What does it mean for rubella to be a teratogen?

It can cross the placenta and cause birth defects Signup and view all the answers

What is virulence in the context of infectious organisms?

The ability to infect the host and cause disease Signup and view all the answers

What is dysentery?

Inflammation/infection of the intestinal tract Signup and view all the answers

What is the primary characteristic of dysentery?

Bloody diarrhea Signup and view all the answers

Which body system does dysentery primarily affect?

Digestive system Signup and view all the answers

What did d’Herelle notice while working with dysentery patients near Paris in 1915?

Not all patients with dysentery died Signup and view all the answers

What did d’Herelle and his associates collect from dysentery patients while working in the hospital?

Stool samples Signup and view all the answers

What was d’Herelle searching for while working with dysentery patients near Paris in 1915?

A dysentery vaccine Signup and view all the answers

What does d’Herelle speculate about recovered patients from dysentery?

They may have a protective substance in their intestines Signup and view all the answers

What is the focus of d’Herelle's inquiry regarding recovered dysentery patients?

The presence of a protective substance in their intestines Signup and view all the answers

What does d’Herelle wonder if recovered dysentery patients have in their intestines?

A protective substance Signup and view all the answers

What did d’Herelle obtain from dysentery patients' stools and mix with Shigella dysenteriae bacteria?

Filtered fluid labeled as 'fluid from recoverees' or 'fluid from deceased dysentery patients' Signup and view all the answers

What was the outcome of the plates from the survivors and the deceased dysentery patients?

Survivors had plaques on the Petri dish, but the deceased did not Signup and view all the answers

What was d’Herelle pondering while working with the 'filtered fluid' obtained from dysentery patients' stools?

Whether there is something in the intestines of patients helping them overcome dysentery Signup and view all the answers

What are the circular clear areas within the lawn of bacteria called?

Plaques Signup and view all the answers

From what does each plaque arise?

Viruses infecting a single bacterium Signup and view all the answers

What happens when the bacterium lyses within a plaque?

New viruses are released and neighboring bacteria are infected Signup and view all the answers

What did D’Herelle believe the areas where bacteria had been killed by 'something' to be?

Bacteriophages Signup and view all the answers

What did D’Herelle suspect these areas to be in relation to bacteria?

Areas where the bacteria have been killed by bacteriophages Signup and view all the answers

What did D’Herelle believe were present in the areas where bacteria had been killed by 'something'?

Bacteriophages Signup and view all the answers

Who suggested the use of filtrate treatment for people affected with dysentery?

Félix d'Hérelle Signup and view all the answers

What was the first bacteriophage therapy used for?

Treating dysentery Signup and view all the answers

What is the primary purpose of bacteriophage therapy?

To target and destroy specific bacteria Signup and view all the answers

Where is the headquarters of the Centers for Disease Control located?

Atlanta, Georgia Signup and view all the answers

What was the primary reason for choosing Atlanta, Georgia as the location for the CDC headquarters?

To address malaria in the southern United States Signup and view all the answers

What is remarkable about the Hepatitis B virus mentioned in the text?

It is a human pathogen with only four genes but is one of the world’s most deadly pathogens Signup and view all the answers

What is the impact of the Hepatitis B virus on humans?

It causes over one million deaths each year from associated liver disease Signup and view all the answers

What makes the Hepatitis B virus amazing, according to the text?

Its ability to cause significant harm with minimal genetic information Signup and view all the answers

How is Hepatitis A primarily transmitted?

Through contaminated food and water Signup and view all the answers

What is the primary route of transmission for Hepatitis B?

Through blood transfusion and needle stick injuries Signup and view all the answers

How is Hepatitis C mainly spread?

Through blood transfusion Signup and view all the answers

Which of the following diseases is a teratogen, capable of causing birth defects?

Rubella Signup and view all the answers

What is the primary characteristic of a teratogen?

It causes birth defects Signup and view all the answers

Which of the following substances is described as the biggest teratogen?

Alcohol Signup and view all the answers

What was the impact of the 1964-1965 rubella epidemic in the U.S.?

12.5 million people. contracted Rubella in the U.S. 11,000 pregnant women lost their babies through miscarriages linked to rubella infections Signup and view all the answers

What was the initial skepticism of doctors and scientists regarding rubella infections?

Infectious agents could not cross the placenta Signup and view all the answers

What was the consequence of the skepticism regarding rubella infections?

Delayed the development of a vaccine against rubella virus Signup and view all the answers

What are the characteristics of Congenital Rubella Syndrome (CRS)?

Cataracts, blindness, deafness, heart defects, and cognitive disability Signup and view all the answers

What has been the impact of the MMR vaccine on CRS?

Drastically reduced the disease and exposure to pregnant women Signup and view all the answers

What is the current status of CRS globally?

Not eliminated, still present in parts of the world with MMR vaccine shortages Signup and view all the answers

Which disease has a lower virulence compared to rubeola?

Rubella Signup and view all the answers

What is the common name for rubeola?

Hard measles Signup and view all the answers

Which disease is considered 'hard measles'?

Rubeola Signup and view all the answers

What is the term used to describe the impaired immunological memories of previously encountered pathogens in children who recover from measles?

Immune amnesia Signup and view all the answers

Which type of cells does the rubeola virus attach to, leading to a potential loss of antibody memory?

B cells Signup and view all the answers

What is the consequence of the number of deaths caused by other infectious agents increasing in children who recover from measles?

Loss of antibody repertoire between 11-73% Signup and view all the answers

Which of the following is an example of an immunocompromised site in the human body?

CNS Signup and view all the answers

Which of the following is NOT considered an immunocompromised site?

Skin Signup and view all the answers

Which of the following areas is mentioned as an immunocompromised site in the text?

Ovaries Signup and view all the answers

What treatment did Isabelle Carnell-Holdaway receive to control the Mycobacterium infection?

Phage infusions and daily swabs of phage cocktail on her skin lesions Signup and view all the answers

What positive outcome was observed after six weeks of phage treatment for Carnell-Holdaway?

Reduction of infection in the liver and improvement in liver function Signup and view all the answers

What is the potential future role of bacteriophages in medical treatment?

Part of a patient’s standard treatment of care for antibiotic-resistant bacteria Signup and view all the answers

What was the initial perception of using bacteriophages to treat bacterial infections?

Seemed 'icky' similar to fecal transplants Signup and view all the answers

What genetic condition did Isabelle Carnell-Holdaway have?

Cystic fibrosis Signup and view all the answers

What was the cause of the infection that spread throughout Isabelle Carnell-Holdaway's body? Received double lung transplant and infection spread throughout whole body.

Mycobacterium Signup and view all the answers

Why weren't there any antibiotics that could treat the Mycobacterium infection?

It was resistant to available antibiotics Signup and view all the answers

How do vaccines work?

By leveraging the adaptive immunity (third line of defense)to produce antibodies against foreign microbes Signup and view all the answers

What is the primary role of adaptive immunity in response to vaccines?

Recognize foreign microbes and produce antibodies against them Signup and view all the answers

What is the key advantage of vaccines leveraging adaptive immunity?

Ability to provide long-term protection against specific pathogens Signup and view all the answers

Which of the following is an example of the body's second line of defense?

Fever Signup and view all the answers

Which of the following is a function of interferons in the immune response?

Inhibiting viral replication Signup and view all the answers

Where would specialized T and B cells belong in our body's defense?

Third line of defense, adaptive immunity Signup and view all the answers

Which type of immunity involves specialized T and B cells?

Adaptive immunity Signup and view all the answers

What distinguishes adaptive immunity from innate immunity?

Adaptive immunity has memory and is pathogen-specific, while innate immunity does not have memory and is non-specific Signup and view all the answers

What is the primary function of IgA antibodies?

Protect against inhaled & ingested pathogens Signup and view all the answers

How many receptor sites does the largest antibody, IgM, have?

10 Signup and view all the answers

Which antibody can be overproduced with allergies and binds to mast cells in the skin & mucous membrane, releasing histamine?

IgE Signup and view all the answers

What is the primary function of IgA antibodies?

Protect against inhaled & ingested pathogens Signup and view all the answers

Which antibody can be overproduced with allergies?

IgE Signup and view all the answers

How many receptor sites does IgM antibody have?

10 Signup and view all the answers

What are antigens?

Foreign substances that elicit an immune response with antibody production Signup and view all the answers

What is the primary function of antigens in the immune system?

To trigger an immune response with antibody production Signup and view all the answers

How are antigens defined?

Foreign substances that elicit an immune response with antibody production Signup and view all the answers

In the context of antigen-antibody interaction, what is the term for the specific region on the antigen that the antibody binds to?

Epitope Signup and view all the answers

What is an antigen?

A foreign substance that elicits an immune response Signup and view all the answers

What are epitopes?

Molecules on the antigen that antibodies attach to Signup and view all the answers

What did Pasteur learn about bacteria and vaccines?

Bacteria can be weakened through prolonged growth and exposure to oxygen to create non-virulent vaccines Signup and view all the answers

What was the result of Pasteur's vaccine on healthy chickens?

The chicken cholera outbreak subsided Signup and view all the answers

What was Pasteur's primary concern regarding his vaccine procedure?

The result in creating a vaccine that could protect healthy chickens Signup and view all the answers

What was the outcome when Pasteur challenged the protected chickens with fresh cultures of P. multocida?

The chickens remained unaffected Signup and view all the answers

What was the fate of the healthy chickens that were not injected with the old culture of bacteria?

They died when exposed to fresh P. multocida Signup and view all the answers

What did Pasteur observe about the broth of bacteria that had been sitting around for weeks?

It seemed to provide protection for the chickens Signup and view all the answers

What is the causative agent for Chicken Cholera?

Pasteurella multocida Signup and view all the answers

Which bacterium is responsible for causing Chicken Cholera?

Pasteurella multocida Signup and view all the answers

What disease is Pasteurella multocida the causative agent for?

Chicken Cholera Signup and view all the answers

What is the process of viral nucleic acid and capsid protein production called?

Biosynthesis Signup and view all the answers

What happens after maturation, where do the viruses go?

Onto new cells Signup and view all the answers

What is the initial step of a virus entering a host cell?

Attachment to binding sites on the host cell membrane Signup and view all the answers

What is the process of viral nucleic acid and capsid protein production called?

Maturation Signup and view all the answers

What is the initial step in the penetration of virus into a host cell?

Attachment to the host cell Signup and view all the answers

What is the role of viral or host enzymes in the penetration of virus into a host cell?

Facilitate uncoating of the virus-----> biosynthesis------> maturation------>release Signup and view all the answers

Why do enveloped viruses 'wrap' themselves with host molecules?

To hide from the host's immune system Signup and view all the answers

What is the main advantage of enveloped viruses taking some of the host cell's membrane with them when budding out?

They are able to 'hide' themselves from the host's immune attack Signup and view all the answers

What is the primary purpose of prophylaxis vaccines?

To protect against further exposure to the pathogen Signup and view all the answers

How does the post-exposure Rabies vaccine work?

It protects even if the rabies virus is present in the body Signup and view all the answers

What is the protective effect of the Rabies vaccine post exposure?

It protects if the virus has not reached the brain Signup and view all the answers

What is a disadvantage of live, attenuated vaccines?

slight chance of back mutation to infectious form Signup and view all the answers

What is the primary advantage of live, attenuated vaccines?

They trigger a strong immune response Signup and view all the answers

Which disease can be prevented by the Sabin vaccine administered via a sugar cube?

Polio Signup and view all the answers

During which period does the number of microbes reach its highest and most severe signs and symptoms are observed?

Period of illness Signup and view all the answers

What happens during the period of covalence?

Number of microbes goes to zero and signs and symptoms go away Signup and view all the answers

When does the mild signs and symptoms with a slight elevated number of microbes occur?

Prodrimal period Signup and view all the answers

What is the shortest possible incubation period for rabies if bitten near the head?

5 days Signup and view all the answers

How long might it take for the rabies virus to move up to the brain if bitten on the hand or foot?

2 years Signup and view all the answers

What is the longest possible incubation period for rabies if bitten on the hand or foot?

2 years Signup and view all the answers

How many deaths result from 1 case of rabies?

1 Signup and view all the answers

What is the fatality rate for rabies based on 1 case?

100% Signup and view all the answers

If there are 5 cases of rabies, how many deaths are expected?

5 Signup and view all the answers

What is the fate of any mammal that gets rabies?

They will die Signup and view all the answers

What is the primary outcome for a mammal infected with rabies?

Death Signup and view all the answers

What is the consequence for any mammal that contracts rabies?

They will not survive Signup and view all the answers

How is rabies primarily transmitted to humans?

Through animal bites or scratches Signup and view all the answers

What type of disease is rabies considered?

Zoonotic disease Signup and view all the answers

What is the main source of the rabies virus in transmission to humans?

Animal saliva Signup and view all the answers

What is a key advantage of killed vaccines?

They can't back mutate Signup and view all the answers

Which vaccine type requires booster shots to elicit a stronger immune response?

Killed vaccines Signup and view all the answers

Which vaccine is an example of a killed vaccine?

Salk polio vaccine (shot) Signup and view all the answers

What is the receptor on muscle cells that the rabies virus attaches to?

Nicotine acetylcholine receptors (nAchR) Signup and view all the answers

Which molecules on the neuron surface does the rabies virus attach to for penetration into the neuron cells?

Neural cell adhesion molecules (NCAM) Signup and view all the answers

Where is the rabies virus hidden from the host's immune system once it penetrates the neuron cells?

Neurons and CNS Signup and view all the answers

Who was the first person to receive Pasteur's rabies vaccine?

Joseph Meister Signup and view all the answers

How often were the vaccine injections administered to Joseph Meister?

Once every 14 days Signup and view all the answers

What was the outcome of Joseph Meister's treatment with Pasteur's vaccine?

He survived without a rabies infection Signup and view all the answers

What did Pasteur find by removing the spinal cords from rabid rabbits and drying them out?

It weakened the virulence of the virus Signup and view all the answers

What was the outcome of the process of removing the spinal cords from rabid rabbits and drying them out on the host's immune system?

It weakened the rabies virus The host's immune system recognized the pathogen and made antibodies Signup and view all the answers

Where does the rabies virus replicate in the host's body?

Muscles Signup and view all the answers

What is the final stage of rabies progression in the host?

Infection of brain neurons leading to encephalitis host becomes agitated, has trouble walking, and quickly succumbs to a coma, and then dies. Signup and view all the answers

How does the rabies virus travel within the host's body?

Through axons in peripheral nerves via axonal transport Signup and view all the answers

Who showed that the cause of poliomyelitis could be transmitted to monkeys?

Karl Landsteiner Signup and view all the answers

Where did Landsteiner go to continue his experiments on poliomyelitis?

Pasteur Institute in Paris Signup and view all the answers

What did people know about polio after Landsteiner's work?

What caused polio Signup and view all the answers

How many receptor sites does the Polio CD155 receptor molecule have?

1 Signup and view all the answers

Where does the Polio CD155 receptor molecule attach to cells?

Throat, intestinal wall, and motor neurons Signup and view all the answers

How many sites does the Polio CD155 receptor molecule have for attachment?

3 Signup and view all the answers

What is a primary impact of bulbar polio with brain stem involvement?

Impaired swallowing and breathing Signup and view all the answers

Which demographic group is especially at risk of high mortality from bulbar polio?

Adults Signup and view all the answers

What is the mortality rate like for bulbar polio with brain stem involvement?

High Signup and view all the answers

What is the primary cause of the problem described in the text?

Overuse and societal pressure Signup and view all the answers

What is the consequence of the described problem?

Motor neuron body disintegration Signup and view all the answers

What is the nature of the problem described in the text?

Degenerative condition Signup and view all the answers

What type of neurons does the polio virus primarily attack?

Motor neurons Signup and view all the answers

What is the main cause of paralysis due to polio infection?

Attack on motor neurons Signup and view all the answers

Which nerve fibers does the polio virus affect in the body?

Only motor neurons Signup and view all the answers

How many genes does the Enterovirus have?

12 genes Signup and view all the answers

How many types or strains of Enterovirus are there?

I, II, and III Signup and view all the answers

How stable is the Enterovirus outside of the body?

It remains infectious for a long time Signup and view all the answers

Study Notes

Bacteriophage Characteristics

A bacteriophage attacks and reproduces inside bacteria.
Bacteriophages do not cause viral infections in humans.

Transduction Process

During transduction, a bacteriophage introduces bacterial genes into another bacterium.
The bacteriophage acts as a vector, carrying genes from one bacterium to another.
The role of a bacteriophage in transduction is to transfer genetic material between bacteria.
For transduction to occur, bacterial DNA must be incorporated into the bacteriophage genome.
The bacteriophage has genes that allow it to integrate into the host bacterium.
The recipient bacterium receives genetic material from the donor bacterium through the bacteriophage.
The donor bacterium is not affected during transduction.
The fate of the recipient bacterium is to receive new genetic material.

Bacteriophage Structure

The main components of a bacteriophage's structure are the head, tail, and genetic material.

Viral Ecology and Genetic Transfer

Viruses play a crucial role in the ecology of Earth, influencing population dynamics and genetic transfer.
A significant function of viruses is to facilitate genetic transfer between organisms.
Viruses impact populations by infecting and altering the behavior of organisms.

Virus Infection

For viruses to enter cells, they require specific receptors on the host cell surface.
The primary requirement for viruses to infect cells is the presence of these receptors.

Tobacco Mosaic Disease (TMD)

TMD is caused by a virus, not bacteria.
The causative agent of TMD is a type of virus that infects plants.
Mayer concluded that TMD is caused by a filterable agent, not bacteria.
The infectious agent is small enough to pass through a filter.

Koch's Postulates

Koch's postulates are a set of criteria used to determine the causative agent of a disease.
In Koch's experiments, injecting bacteria into healthy cows resulted in disease.
Mayer's experiments with plant bacteria and healthy plants yielded similar results.

Osteomyelitis

The primary causative agent of osteomyelitis is bacteria.
Infected bone in osteomyelitis becomes necrotic and difficult to treat.
Osteomyelitis is challenging to treat due to the difficulty of reaching the infected bone.

DTaP Vaccine

The DTaP vaccine protects against diphtheria, tetanus, and pertussis.
The vaccine is intended for children and individuals who have not previously received the vaccine.
The DTaP vaccine includes pathogens that cause these diseases.

Attenuation and Antibiotic Resistance

The primary purpose of attenuation is to weaken a pathogen, making it unable to cause disease.
The desired strength of an attenuated pathogen is weakened but still able to stimulate an immune response.
Attenuation can contribute to antibiotic resistance.

Bordetella pertussis and Whooping Cough

Whooping cough is caused by the bacterium Bordetella pertussis.
The bacterium is primarily spread through respiratory droplets.
Bordetella pertussis releases a cytotracheal toxin that paralyzes the cilia in the respiratory tract.
The bacterium releases its toxin during the catarrhal stage of the disease.

Antibiotic Resistance

The efflux pump protein plays a crucial role in antibiotic resistance by pumping antibiotics out of the cell.
Plasmid genes are related to antibiotic resistance, as they can carry genes that confer resistance.
The efflux pump protein resides in the cell membrane.
Antibiotics that target bacterial ribosomes can lead to resistance if the bacteria develop mutations that prevent the antibiotic from binding.
The primary cause of methicillin-resistant S. aureus (MRSA) is the acquisition of the mecA gene.
The enzyme penicillinase breaks down the beta-lactam ring in penicillin, making it ineffective.

Genetic Transfer and Plasmids

Plasmids are small, self-replicating circular DNA molecules that can transfer genetic material between bacteria.
The primary characteristic of plasmids is their ability to replicate independently of the host chromosome.
Plasmids are located in the cytoplasm of bacteria.
Genetic transfer through conjugation, transformation, and transduction plays a crucial role in the development of new strains and antibiotic resistance.

Conjugation

Conjugation is the process through which bacteria exchange small pieces of DNA through short 'tubes' or a much longer tube.
The donor bacterium does not die during conjugation.
The short 'tubes' are called pili.
DNA transfer occurs through the direct transfer of plasmids between bacteria.
The plasmids in both bacteria are replicated during conjugation.

Transformation

Bacterial transformation is the process through which bacteria take up free DNA from the environment.
DNA transfer occurs through the uptake of free DNA by the recipient bacterium.
The donor bacterium is not affected during transformation.
The outcome of transformation is the acquisition of new genes by the recipient bacterium.

Public Health

In public health decisions, the 'vertical approach' refers to the focus on individual health, whereas the 'horizontal system' focuses on the community and population health.

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Test your knowledge of bacteriophages with this quiz! Learn about these viruses that infect and replicate within bacteria, and discover why humans are not susceptible to viral infections from bacteriophages.