Ch. 2 Microbiology (Hamil)

The __________ of an organism is its ability to cause disease.

pathogenicity

Different microbes are adapted to enter the body in different ways; each way into the body is called a(n) _______________.

portal of entry

What factors influence a pathogen's use of one portal of entry and not another? Choose one or more: A The pathogen's attachment capability B. The reservoir for the organism C. Whether or not the portal of entry is the same as the portal of exit D. The length of the pathogen's lifespan

A and B

The major microorganisms known to have caused pandemics are influenza, Yersinia pestis (bubonic plague), and HIV. Which of the following are reasons why more microbes don't cause pandemics? Choose one or more: A. The organism must be easily transmitted from person to person. B. The organism must be spread by a vector. C. The microbe must cause a respiratory disease because airborne infections spread most easily. D. The agent must require a relatively low infectious dose to cause disease.

A and D

Successful pathogens must do which of the following? Choose one or more: A. Avoid the host's immune system B. Attach or adhere to host cells C. Invade the host D. Cause irreversible disease in the host E. Readily infect various animals

A, B and C

Which of the following organisms would be considered the most virulent, based on their infectious dose (ID50)? A.Rickettsia rickettsii, ID50 = 1 B. Vibrio cholerae, ID50 = 1,000,000,000 C. Mycoplasma tuberculosis, ID50 = 10

A. Rickettsia rickettsii, ID50=1

Why are very young children (under the age of 3) highly susceptible to infection? A. Their immune systems are still developing. B. They are continually exposed to infectious agents. C. Their exercise levels are low. D. Their immune systems are waning.

A. Their immune systems are still developing

Ebola epidemics occasionally occur. The virus that causes Ebola "hides" between epidemics. It is thought that bats harbor the virus, and thus bats are A. a reservoir. B. an insect vector. C. a symptom. D. pandemic.

A. a reservoir

Some pathogens can have more than one portal of entry. Pick the pair of words that will make the following sentence correct. (The first word will fill in the first blank and the second word will fill in the second blank.) HIV can be transmitted via the _______________ route during sexual contact or via the ________________ route during needle sharing. A. urogenital, parenteral B. parenteral, respiratory C. parenteral, fecal-oral D. respiratory, urogenital

A. urogenital, parenteral

Which of the following would be an effective means of limiting a disease spread via a respiratory route? A. wearing a mask that covers the nose and mouth B. washing hands before eating C. wearing condoms during sexual activity D. using fresh needles; in other words, not sharing needles

A. wearing a mask that covers the nose and mouth

A disease that is always present at low levels in a restricted area of the world is known as A. a pandemic disease. B. an endemic disease. C. a zoonotic disease. D. an epidemic disease.

B. An endemic disease

What is the most likely way that expansion of human civilization leads to new human disease outbreaks? A. Expansion changes human genotypes, leading to genotypes that cause increased susceptibility to infectious agents. B. Expansion brings humans into contact with disease reservoirs they were previously isolated from. C. Expansion mitigates climate change, and the stable climate allows for better growth of pathogenic organisms. D. Expansion brings humans further away from medical centers that can diagnose and treat diseases.

B. Expansion brings humans into contact with disease reservoirs they were previously isolated from

You and your immunocompromised neighbor both consume undercooked meat containing a pathogenic strain of E. coli. Your neighbor becomes ill (but eventually recovers), whereas you never experience any symptoms. Which of the following is true? A. The E. coli was an ectoparasite in your neighbor, but not on you. B. The E. coli strain ingested was an opportunistic pathogen. C. You were never infected with the E. coli strain. D. Both you and your neighbor had a disease caused by the E. coli pathogen.

B. The E. coli strain ingested was an opportunistic pathogen.

Which of the following scenarios describes an opportunistic pathogen? A. a diarrhea as a result of eating chicken contaminated with salmonella B. bacterial pneumonia following a case of the flu C. a case of strep throat D. an STD caused by sexual intercourse E. conjunctivitis caused by staph

B. bacterial pneumonia following a case of the flu

A mutualistic relationship exists between human hosts and A. parasites. B. microbiota. C. pathogens. D. fomites.

B. microbiota

Place the following stages of infectious disease in the order in which they occur: A. Decline phase B. Illness phase C. Incubation period D. Convalescent phase E. Prodromal phase

C,E,B,A,D

Symptoms develop rapidly in which type of infection? A. Latent infection B. Chronic infection C. Acute infection D. Disseminated infection

C. Acute infection

Among a population of people exposed to influenza virus, those who frequently wash their hands or use hand sanitizers are less likely to contract the flu. This is an example of which factor that plays a role in whether a host will contract an infectious disease? A. Occupation B. Immune status C. Host hygiene D. Nutrition and exercise E. Age

C. Host hygiene

A particular flu strain spreads easily from person to person and also has high mortality. Which of the following is true of this flu strain? A. It has low infectivity and low virulence. B. It has high infectivity but low virulence. C. It has high infectivity and high virulence. D. It has low infectivity and high virulence.

C. It has high infectivity and high virulence.

The fungus Pneumocystis jirovecii easily infects people, but rarely causes disease in healthy people. What is this type of pathogen called? A. Virulent pathogen B. Primary pathogen C. Opportunistic pathogen D. True pathogen

C. Opportunistic pathogen

Agents transmitted by mosquitoes or other insects enter their human hosts via what portal of entry? A. Urogenital route B. Respiratory route C. Parenteral route D. Oral route E. Fecal-oral route

C. Parenteral route

Pathogen A has an LD50 of 1,000, and pathogen B has an LD50 of 75. Which of the following is true? A. Pathogen A and pathogen B are equally virulent. B. Pathogen A is more virulent than pathogen B. C. Pathogen B is more virulent than pathogen A. D. There is no way to judge the relative virulence of the organisms.

C. Pathogen B is more virulent than pathogen A.

MERS, a respiratory illness first reported in 2012, is caused by a virus that is shed by infected camels and can spread to humans. In this example, camels serve as A. a parasite. B. a fomite. C. an incubator. D. an agent of vertical transmission.

C. an incubator

Pick the pair of words that will make the following sentence correct. (The first word will fill in the first blank, and the second word will fill in the second blank.) A _________ is a disease manifestation that can be observed by clinicians, whereas a __________ is a disease manifestation that can only be felt by the patient. A. syndrome, symptom B. sign, syndrome C. sign, symptom D. symptom, sign

C. sign, symptom

What is the underlying factor that explains how age and nutrition can impact disease susceptibility? A. Both age and nutrition can affect host genotype. B. Both age and nutrition can affect the portal of entries available to pathogens. C. Both age and nutrition can affect host exposure to pathogens. D. Both age and nutrition can affect host immune status.

D. Both age and nutrition can affect immune status

What is an infection transmitted from a health care worker to a patient called? A. Focal infection B. Mixed infection C. Community-acquired infection D. Iatrogenic infection

D. Iatrogenic infection

Walter defecates in the company restroom, does not wash his hands thoroughly, and then uses the office coffee pot, transferring bacteria onto the handle of the pot. Maria pours some coffee, and then she goes to her desk to eat a muffin, ingesting some of the bacteria she picked up from the coffee pot. Which of the following is true of Maria's bacterial infection? A. The infection occurred via an aerosol. B. The infection occurred via direct contact. C. The infection occurred via vertical transmission. D. The infection occurred via indirect contact.

D. The infection occurred via indirect contact

Which of the following modes of transmission is direct? A. a baby's teething ring B. a flea C. creek water D. a sneeze E. lettuce leaves in a salad

D. a sneeze

What might allow disease vectors such as mosquitoes to increase their global geographic range? A. a reduction in the range of their food sources B. a reduction of water sources mosquitoes need for breeding C. Mosquitoes cannot expand their range because they do not fly well enough to enter new regions. D. an expansion of suitable habitat because of climate change

D. an expansion of suitable habitat because of climate change

What determines whether an individual will contract a particular infectious disease? A. neither the host's susceptibility to the pathogenic agent nor the presence of the pathogenic agent B. only the presence of the pathogenic agent C. only the host's susceptibility to the pathogenic agent D. both the host's susceptibility to the pathogenic agent and the presence of the pathogenic agent

D. both the host's susceptibility to the pathogen agent and the presence of the pathogenic agent

Septicemia is defined as the following: A. the presence of bacteria in the blood B. the presence of viruses in the blood C. the presence and replication of viruses in the blood D. the presence and replication of bacteria in the blood E. the presence of toxins in the blood

D. the presence and replication of bacteria in the blood

Which of the following is not a host-pathogen interaction? A. a virus binding to its receptor on a host cell B. a change in surface proteins by the pathogen C. a signal from the pathogen that causes the host immune cells to initiate apoptosis D. iron-binding proteins used by the host to sequester available iron E. a gene for antibiotic resistance in the pathogen

E. a gene for antibiotic resistance in the pathogen