MICRO212: 35-36

This microorganism is typically an extracellular pathogen.

Aspergillus

Check all of the measures that are employed by epidemiologists to control a chain of infection.

Breaking the connection between the source of the infection and susceptible individuals Reducing or eliminating the source of infection Increasing metagenomic studies Limiting antibiotic use to prevent resistant organisms Reducing the number of susceptible individuals

In response to the events of September and October 2001, the U.S. government created a number of agencies and committees to counteract terrorism under the auspices of the __________.

Department of Homeland Security

The total number of individuals infected in a population at any one time is referred to as ________.

prevalence rate

In 1900, the leading single category of death in the United States was pneumonia/influenza, accounting for 11.8% of deaths. In 2010, pneumonia/influenza accounted for only 2.0% of deaths in the United States. This change is largely due to ______.

the impact of public health surveillance

When two adjacent thymine molecules are joined by a covalent bond as a result of exposure to UV light, this structure is referred to as a

thymine dimer.

One strategy for exploiting host cells that is used by certain bacteria such as Listeria, Shigella, and Rickettsia is to ________.

use the actin filaments of the host cytoskeleton to facilitate motility through the host cell thereby enhancing infection of neighboring cells

Both of these organisms are susceptible to what compound?

Bleach

Match the following terms with the statement that best describes them.

Colonization - This term refers to a microbe establishing itself and multiplying on a body surface Primary Pathogen - This term refers to a microbe that causes disease in otherwise healthy individuals Opportunistic - This term refers to a microbe that causes disease only when the body is already compromised in some way Virulence - This term refers to the degree of pathogenicity (disease causing ability) of a microbe

What is the purpose of the white card seen in this image?

It blocks the UV light from one side of the plate to produce a control.

Which of the following are risks associated with UV exposure? Check all that apply.

Skin cancer Eye damage Hearing loss Prostate cancer

How does this white card work to produce a control side of the plate?

UV light cannot penetrate a solid object so the covered side of the plate is not exposed.

Pathogens produce virulence factors primarily to ________.

outcompete host cells for resources

Infectious disease outbreaks often follow certain patterns, with specific terms used to designate each pattern. Match the term with the recognized pattern of disease associated with that term.

peak level reached in short period of time, followed by rapid decline: common-source epidemic - 2 slow rise, followed by gradual decline in cases: propagated epidemic - 1 increase in disease around the world: pandemic - 3

There are many things that people can do to help prevent the spread of infectious disease. Match each term with the action that it represents.

periodic use of bleach on a kitchen countertop: Disinfection - 1 routine treatment of drinking water: Sanitation - 2 use of antibiotics for a bacterial infection: Chemotherapy - 3

Why do most microorganisms not cause disease upon entry of a human host?: Resident microbiota compete for space and nutrients Adaptive immunity from a previous exposure immediately removes the organism Innate mechanisms such as complement activation and phagocytosis eliminate the potential pathogen

All of the choices are correct.

Authorities have established an integrated system of laboratories so that a rapid and coordinated response to bioterrorism is in place. This conglomerate of laboratories is maintained by the ________.

Laboratory Response Network (LRN)

Analyze the paragraphs below and drag the labels to complete the sentences that discuss the origin and nature of pathogenicity islands.

Large segments of bacterial chromosomal and [plasmid] DNA have been found to encode [virulence] factors. These DNA segments are called pathogenicity islands, and they appear to have been inserted into the existing DNA of organisms as they evolved from [nonpathogenic] cells into those that are capable of causing disease. Pathogenicity islands generally increase bacterial virulence and are absent in nonpathogenic members of the same genus or species. They range from [10 to 200] kilobases and code for a variety of proteins that include pili and [secreted] proteins. Staphylococcus aureus has a pathogenicity island that codes for several [superantigens], including the toxin that is active in toxic shock syndrome, while Shigella flexneri encodes a Type III [secretion system] that acts as a cytotoxin.

Match the following terms related to disease processes with the appropriate description.

The potential to cause disease: Pathogenicity - 1 The magnitude of harm caused by an organism: Virulence - 2 Segments of the genome that code for virulence factors: Pathogenicity islands - 4 The ability of a pathogen to spread to neighboring cells and adjacent tissues: Invasiveness -3

An influenza virus from a chicken and an influenza virus from a human both end up in a pig, resulting in influenza viruses containing mixed genetics and mixed H and N surface receptors. This is an example of antigenic shift. What are the likely results of this event? (Check all that apply.)

This influenza virus is no longer recognized by the immune system of the human. The population of susceptible individuals will increase. Morbidity rates will increase. This virus will be less virulent to humans. The level or protection provided by herd immunity will decrease.

A patient infected with HIV by a partner in 1997 responds well to treatment and exhibits a viral load of 0 in 2007. Shortly thereafter, the individual reconnects with the partner that infected them with HIV a decade earlier and after embarking on a sexual relationship, the patient's viral load climbed to 24,000/ml. This is an example of __________.

antigenic drift

Determine what type of A-B toxin (cytotoxin, neurotoxin, or enterotoxin) the following microbes produce.

cytotoxin- Bordetella pertussisneurotoxin- Clostridium botulinumenterotoxin- Vibrio cholerae

Which of the following statements is false regarding the efforts made by the U.S. government to prepare for a potential bioterrorism attack?

FBI screening of all laboratory workers who have access to potential agents of bioterrorism

The public health measures implemented in the 1900s have greatly changed the quality of life in the United States today, either directly or indirectly. How? (Check all that apply.)

Implementation of strict sanitation guidelines Widespread use of vaccines Increased life expectancy

Why might a disease with low occurrence in the United States reemerge as a dangerous pathogen?

Horizontal gene transfer creates antibiotic resistant strains that evade our existing drugs: maybe

There are three types of control measures used by scientists to prevent and control epidemics. Categorize each action into the appropriate type of control measure.

Reduce or eliminate the source or reservoir of infection: Quarantine of carriers, use of antimicrobial drugs, wastewater treatment Break connection between source of infection and those susceptible: Pasteurization, insecticides, drinking water chlorination, mandatory hand washing by food handlers Reduce number of susceptible individuals and raise herd immunity: Passive immunization, prophylactic treatment, active immunization.

What is the number one type of healthcare-associated infections in the United States?

Urinary tract infections

Which of the following organisms contain a pathogenicity island that encodes for Type III secretion proteins?

Yersinia pestis Helicobacter pylori Salmonella enterica Vibrio cholerae Shigella flexneriShigella flexneri