Microbiology (EXAM #1) CH. 2 Homework & Reading Questions

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

pathogenicity

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. parenteral, fecal-oral B. respiratory, urogenital C. parenteral, respiratory D. urogenital, parenteral

urogenital, parenteral

https://sw5.wwnorton.com/problemsets/filemanager/userfiles/[email protected]/AQ0205.jpg Typhoid Mary was a female cook in the New York region in the early 1900s. She was found to be a carrier of typhoid and spread it through her cooking. She was known for being quite unhygienic—not washing her hands after bowel movements—often causing many of the patrons to become ill with typhoid, too. What type of infection cycle does this illustrate? A. indirect transmission B. vertical transmission C. direct transmission D. vehicle transmission

vehicle transmission

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

wearing a mask that covers the nose and mouth

Place the following stages of infectious disease in the order in which occur: convalescent phase prodromal phase illness phase incubation period decline phase

1. incubation period 2. prodromal phase 3. illness phase 4. decline phase 5. convalescent phase

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

Acute infection

https://sw5.wwnorton.com/problemsets/filemanager/userfiles/[email protected]/2.8.jpg One way to measure virulence is to calculate the lethal dose 50% (LD50): the number of pathogens required to kill 50% of an experimental group of animal hosts. Which agent in the figure below is more virulent?

Agent #1

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

Attach or adhere to host cells Invade the host Avoid the host's immune system

What is the underlying factor that explains how age and nutrition can impact disease susceptibility? A. Both age and nutrition can affect host immune status. 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 genotype.

Both age and nutrition can affect host immune status.

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

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

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. Immune status B. Host hygiene C. Nutrition and exercise D. Occupation E. Age

Host hygiene

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

Iatrogenic infection

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 high infectivity but low virulence. B. It has low infectivity and high virulence. C. It has low infectivity and low virulence. D. It has high infectivity and high virulence.

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. Primary pathogen B. Opportunistic pathogen C. True pathogen D. Virulent pathogen

Opportunistic pathogen

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

Parenteral route

Read the case history and then answer the questions: Risky Business in the Lab In 2004, three people in Boston came down with a virulent form of pneumonia. An investigation by public health officials discovered that all three worked at the same laboratory studying Francisella tularensis, a bacterium that is highly infectious (although not usually spread by person-to-person contact). Under specific conditions, the organism can be aerosolized and inhaled and cause deadly pneumonia—making it a possible bioterrorism agent. Its handling is highly restricted by the U.S. Department of Homeland Security. Scientists studying this bacterium must use extreme precautionary measures to ensure that it cannot escape the laboratory. The investigation determined that the Boston researchers had indeed contracted tularemia. The scientists appear to have handled the organism in several instances without wearing or using proper protective gear—for example, examining agar plates containing the organism outside a biosafety containment hood. From the type of disease and the laboratory procedures performed, it seemed that the victims, who all fully recovered, inhaled the organism while working with it. Part 1: How did the infected lab workers expose themselves to Francisella tularensis? A. Food-borne route B. Respiratory route C. Parenteral route D. Oral route Part 2: Different microbes are adapted to enter the body in different ways; each way into the body is called a(n) ____________. Part 3: What factors influence a pathogen's use of one portal of entry and not another? Choose one or more: A. Whether or not the portal of entry is the same as the portal of exit B. The length of the pathogen's lifespan C. The reservoir for the organism D. The pathogen's attachment capability

Part 1: Respiratory route Part 2: portal of entry Part 3: The reservoir for the organism The pathogen's attachment capability

Read the case history and then answer the questions: The Third Pandemic In 1884, Yong Ding was a 38-year-old male in Canton, in southern China. Life was hard, but Yong Ding, a cook, still managed to support his family. As he walked to his restaurant each day, he barely noticed the small bands of rats scurrying through the streets. Disease was rampant that year; victims of the shuyi (rat epidemic) were stacked like firewood in the streets, five bodies high in places, waiting to be taken for burial. Yong knew that the disease started as a swollen gland in the armpit and often had a black appearance (now called a bubo). He checked himself daily for these swellings and, seeing none, always felt relief. Then, one morning, he found one. Within days, Yong Ding began coughing blood as the agent (a mystery at the time) spread though his bloodstream to his lungs. Once that happened, Yong Ding knew death was not far behind. More than 60,000 people died this way in what was to be the start of the third pandemic of bubonic plague. Yong Ding's body was one of many lining the street that year. Part 1: More than 60,000 people died from the third pandemic of bubonic plague. Where does the name "bubonic" come from? A. The location of the pandemic in China B. The type of rat that carried this disease C. The places where the bodies were piled D. The swollen lymph node Part 2: What does the term "pandemic" mean? A. A disease that is always present in a community and is seen at a low rate B. A situation in which many cases develop in a community over a short period of time C. A worldwide epidemic D. A disease for which an animal reservoir harbors the causative organism Part 3: 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 spread by a vector. B. The agent must require a relatively low infectious dose to cause disease. C. The organism must be easily transmitted from person to person. D. The microbe must cause a respiratory disease because airborne infections spread most easily.

Part 1: The swollen lymph node Part 2: A worldwide epidemic Part 3: The agent must require a relatively low infectious dose to cause disease. The organism must be easily transmitted from person to person.

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 is more virulent than pathogen B. B. Pathogen B is more virulent than pathogen A. C. Pathogen A and pathogen B are equally virulent. D. There is no way to judge the relative virulence of the organisms.

Pathogen B is more virulent than pathogen A.

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

Rickettsia rickettsii, ID50 = 1

There are many signs and symptoms below. Identify which is a sign and which is a symptom by dragging each into the correct bin. (Which is a sign and which is a symptom?) Fever Soreness High blood pressure Toxemia Stomachache Fatigue Jaundice Pain Cough Nausea Lymphadenopathy

Signs: Fever High blood pressure Toxemia Jaundice Cough Lymphadenopathy Symptoms: Soreness Pain Nausea Fatigue Stomachache

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. Both you and your neighbor had a disease caused by the E. coli pathogen. B. You were never infected with the E. coli strain. C. The E. coli was an ectoparasite in your neighbor, but not on you. D. The E. coli strain ingested was an opportunistic pathogen.

The E. coli strain ingested was an opportunistic pathogen.

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 direct contact. B. The infection occurred via indirect contact. C. The infection occurred via an aerosol. D. The infection occurred via vertical transmission.

The infection occurred via indirect contact.

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

Their immune systems are still developing.

Many of your personal daily habits have an impact on your susceptibility to disease. What is the simplest behavior that you can do in everyday life to drastically decrease your susceptibility to disease and pathogens? A. Take your medications as directed. B. Wash your hands frequently. C. Eat nutritiously at every meal. D. Excercise 30 minutes every day.

Wash your hands frequently.

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 symptom. B. a reservoir. C. pandemic. D. an insect vector.

a reservoir.

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

an endemic disease.

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

an expansion of suitable habitat because of climate change

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. an incubator. B. an agent of vertical transmission. C. a fomite. D. a parasite.

an incubator.

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

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

A fever is a measurable sign. Symptoms are not measurable, and are only observed and felt by the patient. Which of the following would be a symptom? A. white blood cell count B. headache C. rash D. runny nose

headache

https://o.quizlet.com/gE4LCXJbwSPFZ.zmMpd4-w.png (Photo gives answer) Label the figure with the correct portals of entry. A. Genital route B. Eye entry C. Respiratory route D. Parenteral route E. Oral route

https://o.quizlet.com/gE4LCXJbwSPFZ.zmMpd4-w.png

https://o.quizlet.com/pLYZw.sr2OzydYQLWEysBw.png (Photo gives the answer) Label the figure of infection cycles with the correct terminology. A. Vertical transmission B. Indirect transmission C. Direct transmission D. Vehicle transmission E. Accidental transmission

https://o.quizlet.com/pLYZw.sr2OzydYQLWEysBw.png

Which of the following has the stages of infectious disease in the correct order? A. incubation phase, invasive phase, prodromal phase, decline phase, convalescent phase B. incubation phase, prodromal phase, invasive phase, convalescent phase, decline phase C. incubation phase, prodromal phase, invasive phase, decline phase, convalescent phase D. invasive phase, prodromal phase, incubation phase, decline phase, convalescent phase

incubation phase, prodromal phase, invasive phase, decline phase, convalescent phase

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

microbiota.

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. symptom, sign B. syndrome, symptom C. sign, symptom D. sign, syndrome

sign, symptom