question

True or False: An infection always leads to disease.

answer

FALSE

question

Virulence

answer

Measure of pathogenicity

question

Pathogen

answer

Microbial parasites

question

Normal microbial flora

answer

Microorganisms usually found associated with human body tissue.

question

Disease

answer

Damage or injury to the host that impairs host function.

question

Pathogenicity

answer

The ability of a parasite to inflict damage on the host.

question

Describe two situation in which a pathogen can act as an opportunistic pathogen

answer

Immune system: functionally declining and weak due to influenza and someone have bacterial pneumonia -pathogen is introduced into a new place and takes advantage to grow and cause harm to us -Appendicitis

question

One microenvironment of the skin is an area where glands produce an oily substance called A. mucus. B. sebum. C. fimbrae. D. lipid A.

answer

B. sebum

question

Normal flora ________ colonization of pathogenic organisms. A. promote B. prevent C. maintain D. accelerate

answer

B. prevent

question

Extensive growth of the streptococci in a thick bacterial layer on acidic glycoproteins on the teeth is called: A. dental plaque. B. dental caries. C. dental biofilm. D. periodontitis.

answer

A. dental plaque.

question

Antibiotics can alter gut microbiota. Which of the following is most likely to also alter gut microbiota? A. amount of sunlight a person is exposed to B. diet C. soaps, shampoos and deodorants D. exercise

answer

B. diet

question

Under what conditions could a member of the gut microbiota become a pathogen?

answer

Disruption of the microbiota leads to pathogen outgrowth. One example is Salmonella it can proliferate and induce inflammation if the resident bacterial community is disrupted by treatment with antibiotics or if recipient has a low-complexity microbiota. . -ruptured appendix -antibiotics

question

Based on the image and information provided, which features contribute to the spread of C. difficile in a hospital environment?

answer

hard endospores

question

Draw an arrow on this graph in the direction of increasing virulence.

answer

Right towards left <---------------- Highly Virulent : dangerous pathogens; lethal dose of mice killed 50%. Doesn't take a lot of pathogens to make you sick.

question

As you move through the digestive tract the amount of available oxygen _____________ while the pH _____________.

answer

decreases, increases

question

Attenuation

answer

The decrease or loss of virulence of a pathogen

question

Highly virulent pathogens

answer

these pathogens show little difference in the number of cells required to kill 100% of the population as compared to 50% of the population

question

Which of the following would be correct about our microbiota? A. The lower respiratory tract typically lacks microflora in healthy individuals. B. Microflora typically are found on all surfaces of the respiratory tract. C. The bladder is only sterile in males. D. Women are more prone to urinary tract infections. E. Streptococci and Staphylococci are the most common causes of urinary tract infections.

answer

A. The lower respiratory tract typically lacks microflora in healthy individuals. D. Women are more prone to urinary tract infections.

question

Two reasons why the lower respiratory tract is not normally colonized with microbiota

answer

mucus traps microbes and prevents them from moving further through the respiratory system. Cilia sweep the trapped microbes up and away from the lower respiratory tract. The air flow slows as it moves through the respiratory tract. The abundances of macrophages in the lungs remove most of the microbes that arrive there.

question

Explain why women of childbearing age often develop a vaginal yeast infection when they are on antibiotics?

answer

This lowers the amount of lactobracillis that help keep the pH of the vagina slightly acidid. Yeast take advantage of the rising pH and increase their growth leading to the yeast infection.

question

Streptocoocus pyogens utilizes M protein and ________ to form microfibrils that facilitate attachment to host cells. A. lipoteichoic acid B. mucus C. plaque D. lipid A

answer

A. lipoteichoic acid

question

Staphylococcus aureus produces ________, leading to fibrin clots that protect them from attack by host cells. A. collagenase B. coagulase C. lipase D. amylase

answer

B. coagulase

question

Which of the following is more likely to cause urinary tract infections? A. fimbriated strains of Escherichia coli B. non-fimbriated strains of Escherichia coli C. both fimbriated and non-fimbriated strains of Escherichia coli D. None of the answers are correct.

answer

A. fimbriated strains of Escherichia coli

question

Which of the following is correct pertaining to cytolytic toxins? A. are extracellular proteins. B. cause cell lysis and death. C. damage host cytoplasmic membrane. D. normally form part of the cell wall. E. can lead to pus production.

answer

A. are extracellular proteins. B. cause cell lysis and death. C. damage host cytoplasmic membrane. E. can lead to pus production.

question

Breaks down tight junctions and connective tissue

answer

hyalurdoinase

question

Causes vomiting and diarrhea

answer

entertoxin A

question

Dissolves fibrin clots

answer

streptokinase

question

Causes RBC to break down (hemolysis)

answer

streptolysin S and O

question

Leads to systemic shock

answer

toxic shock toxin

question

Ouch, you have a gum infection. After flossing you notice blood on the floss and tootbrush. Some bacteria have now entered your blood. This would be called:

answer

bacteremia (the presence of bacteria in the blood)

question

Which of the following is correct pertaining to endotoxins? A. Made up of the lipid A portion of the LPS complex. B. Produced by both Gram positive and Gram negative cells. C. Considered moderately toxic and requires a large amount to be fatal. D. Often encoded on bacterial plasmids. E. Can lead to fever, diarrhea, and vomiting

answer

A. Made up of the lipid A portion of the LPS complex. C. Considered moderately toxic and requires a large amount to be fatal. E. Can lead to fever, diarrhea, and vomiting

question

Produced by Clostridium perfringens and is also called alpha toxin. Digests phospholipids. Inactivates elongation factor 2 thus blocking protein synthesis.

answer

Lecithinase (alpha toxin)

question

Inactivates elongation factor 2 thus blocking protein synthesis.

answer

Diphtheria toxin

question

Leads to an overproduction of cAMP and the secretion of chloride and bicarbonate ions from the small intestinal cells into the intestinal lumen.

answer

Cholera toxin

question

Binds to inhibitory interneurons blocking the release of glycine. Causes spastic paralysis.

answer

Tetanus Toxin

question

Kills nucleated cells and acts as a hemolysin. Produces a membrane spanning pore.

answer

Staphylococcal alpha toxin

question

Our body is protected by the ___________ associated with epithelial tissues unless a pathogen can use _____________ to break through this barrier.

answer

tight junctions / hylauronidase

question

An adult usually has an extensive system of normal flora associated with our ______________ and this prevents botulism bacteria from attaching and releasing their _______________ causing toxin.

answer

digestive tract / flaccid paralysis

question

A hard-core, steak-loving athlete has fallen for a vegan. In order to maintain harmony in their relationship, the athlete has willingly given up meat and all animal products in their diet. They are now on a strictly plant-based diet. What would you expect to see? A. a change in the gut microbiota B. loss of microbiota that secrete proteases C. an increase in microbes that secreate cellulases D. all of the above

answer

D. all of the above

question

Which type of mutation would have a more lethal effect on the bacterium?

answer

Endotoxin mutation will be more lethal

question

A disease that is present in unusually high numbers throughout the world is called a(n)

answer

pandemic

question

A ________ is a disease that primarily infects animals but can be transmitted to humans.

answer

zoonoses

question

The onset of a given epidemic is indicated by a sharp rise in the number of cases reported daily over a brief interval. This indicates that the mode of transmission is:

answer

common source

question

Which of the following is an example of herd immunity?

answer

If 70% of the population is immunized against polio, the disease will be essentially absent from the population.

question

Which of the following shows the correct relationship among the epidemiology terms listed?

answer

prevalence >incidence > mortality

question

Which stage of an acute infectious disease occurs between the time the organism begins to grow in the host and the appearance of disease symptoms?

answer

incubation period

question

What is a/are potential reservoir (site where the pathogen has to reproduce) (s) for viruses that could infect a human? A. water B. insects C. bats D. fomites

answer

bats

question

What do we call a disease that is new in the human population?

answer

emerging

question

1. The virus underwent a significant antigenic shift compared to other circulating strains

answer

H1N1 Pandemic

question

2. Rapid mutation of the pathogen followed by adaptation and change in the population

answer

HIV Pandemic

question

3. Lack of sewage treatment and clean drinking water.

answer

Cholera pandemic

question

Which of the following would an effective biological weapon?

answer

A disease transferred by indirect contact with a high basic reproduction number and mortality would be an effective biological weapon.

question

A person that does not have symptoms of a disease but can transmit it to others is called a:

answer

carrier

question

An endemic disease usually involves ________ infections, and an epidemic is normally caused by ________ infections.

answer

chronic/ acute

question

Which of these factors result(s) in the emergence of new pathogens?

answer

A. human behavior B. economic development C. international travel

question

Predict the number of cases of pertussis in the US in the future, if there are high rates of vaccinations and boosters.

answer

it decreases (goes down)

question

Which of the following statements regarding herd immunity is true?

answer

C. Herd immunity results when a relatively high proportion of the population is immune B. Herd immunity can confer protection to an entire population

question

Select all of the following that are true statements regarding microbial interactions.

answer

B. Humans contain many bacteria in their colon that form a mutualistic association with their host. C. When two organisms spends at least part of its life closely associated with another organism it is engaged in a symbiotic relationship.

question

Which of the following are more likely to be implicated in food poisoning (as opposed to a food infection)? F. Listeria monocytogenes E. Clostridium botulinum D. Shigella dysenteriae A. enterohemorrhagic E. coli C. Salmonella enterica B. Staphylococcus aureus

answer

B. Staphylococcus aureus E. Clostridium botulinum

question

Causative agent of an infection affecting the nervous system that causes spasming of muscles and muscle stiffness, usually transmitted through a break in the skin.

answer

A. Clostridium tetani

question

Clostridium difficile is a Gram-positive, endospore forming anaerobe. Is endotoxin part of its virulence factor toolkit?

answer

D. no, endotoxin is associated with LPS, and C. difficile does not have LPS.

question

Why do pandemics occur with influenza when influenza is endemic in societies around the world?

answer

anti-gentic drift (look at powerpoint

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