Mastering Microbiology Ch14 Extra Credit

What is the etiologic agent of typhoid?

Samonella

When would endotoxins be released from a bacterial cell?

When the cell dies

How can capsules enable bacteria to evade the immune system?

Capsules block the complement biding sites on the surface of the pathogen.

Which microorganism requires the low pH inside a phagolysosome in order to reproduce?

Coxiella burnetii

Which category describes the occurrence of this disease?

Sporadic

Which of the following virulence factors would be found in Staphylococcus aureus?

Staph

Measles viruses are capable of inactivating host defenses by

suppressing the immune system

Which of the following features of Salmonella prevent it from being phagocytosed?

Flagella

Certain traits that allow pathogens to create infection and cause disease are termed

Virulence

What features of West Nile virus make it an emerging disease of special concern?

West Nile virus is an arthropod-borne virus transmitted by mosquitoes. West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America. West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.

Pneumonia is a disease of the lungs. What is the most likely mode of transmission for pneumonia pathogens?

Airbone

Based on the data supplied, what was the approximate mortality rate for this outbreak?

14%

During his research on West Nile virus, Bill learned that this virus is placed within a functional grouping known as arboviruses. What is meant by the term arbovirus?

An arbovirus is an arthropod-borne virus. An arbovirus is maintained in nature through biological transmission.

It has been determined that the agent is a fungus. Which category of antimicrobial drug will likely be the best choice for treatment of fungal pneumonia?

Azoles

Which domain of the A-B toxin binds to cell surface receptors on the host cell?

B domain

Match the terms for disciplines in epidemiology with the most appropriate definition.

Descriptive epidemiology: Observe and collect data concerning a disease. Experimental epidemiology: Design and conduct a test of a hypothesis about a disease. Analytical epidemiology: Make a detailed investigation of data collected concerning a disease.

What are the clinical signs and symptoms of typhoid fever?

Fever and rose spotted rash

Dr. John Snow's investigation of the cholera epidemic of 1854 most closely matches which approach to epidemiology?

Descriptive

Sputum samples from some of the patients were sent to a lab. These samples all showed a strain of bacteria not normally found in the human respiratory tract of healthy people. Assuming Koch's postulates are being followed, place the following steps in the order in which they would occur to determine the causative agent of the disease.

Determine, Isolate, Inoculate, Re-isolate

How could this epidemic be stopped without firing the worker?

Educate the worker about personal hygiene and use of an outhouse or designated bathroom. Instruct him to thoroughly wash his hands with clean soap and water after using the facilities.

The brain tissue of the birds indicated the possibility of encephalitis. What is encephalitis, and why should this type of infection cause concern among health care professionals?

Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.

How does the protozoan Trypanosoma evade detection by the immune system?

It can change the surface antigens

Which of the following is the best mode of controlling the spread of West Nile infections?

Limit exposure to mosquitoes to prevent the transmission of West Nile virus.

Endotoxins are also known as

Lipid A

Where is the site of Shigella attachment in the host?

M Cells

Meningitis and gonorrhea are caused by

Neisseria species.

A patient who has been hospitalized with uncontrolled muscle spasms has probably been infected with bacteria that secrete a(n)

Neurotoxin

Drag the description of Dr. Snow actions or activities to the step of the scientific method it most closely fits.

Observation leads to formulation of a question: Observations suggest to Dr. Snow water is involved in cholera. Formulation of a hypothesis to address a question: Observations suggest to Dr. Snow water is involved in cholera. Design and conduct experiments: Not Applicable Collect and analyze data: Dr. Snow collects information about patients' activities prior to becoming ill. Scientist decides to accept, reject or modify a hypothesis: Dr. Snow concludes a specific well is the source of the cholera cases.

Match the field of epidemiology with the step of the scientific method it most closely fits.

Observation- descriptive Formulation- Experiment Design- nothing Scientist- analytical

Which of the following microorganisms use M protein to avoid destruction of a phagocyte?

Streptococcus pyogenes

How are superantigens different from other types of exotoxins?

Superantigens cause an overstimulation of the host immune system.

A person who attended a picnic early in the day develops a very high fever and is unresponsive by the evening. This person most likely has been exposed to a(n)

Superatigen

How do Shigella cells move between host cells?

They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another

There are five sequential stages of disease that are shared among most infectious diseases.

The time between infection and occurrence of the first symptoms is termed the incubation period. A time of mild generalized symptoms occurring before more serious symptoms is called the prodromal period. The most severe stage of disease with serious symptoms and/or signs occurs during the illness. The body gradually returns to normal as symptoms begin to subside during the decline. The body recovers from the disease and returns to normal during the convalescence.

How is Streptococcus pneumoniae able to avoid destruction by a phagocyte?

Their capsules make them "slippery" to phagocytes.

How do fibrinolysins enhance a pathogen's virulence?

They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin.

Which reservoir of infection most likely harbors an airborne fungal agent capable of causing pneumonia?

contaminated misters spraying water on the produce

An exotoxin that has the ability to kill or damage host cells is referred to as a(n)

cytotoxin

What is the reservoir for this disease organism, Salmonella enterica serotype Typhi?

humans

The scientific method is a four-step framework for the process of scientific investigation. Scientists have successfully applied the scientific method to address problems and questions for more than a century. The application of the scientific method has helped move science from philosophical debate to an understanding of the world around us based on reproducible facts and phenomena.

observation, formulate, design, scientist

Which of the following microorganisms actually grows inside the macrophage?

tuberculosis

Which of the following enzymes breaks down the "glue" that holds cells together?

Hyaluronidase

Why is a release of endotoxin into the bloodstream potentially deadly?

It can be lowered

Drag the appropriate labels to their respective targets.

Top to bottom: Ligand, Sugar, receptor, cytoplasmic, host cell

How was this carrier identified?

Urine sample

Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease?

West Nile virus outbreaks have increased in number and affected areas since 1937.

Which of the following would be the first sign of an infection that resulted in the release of endotoxin?

Fever

Where do Salmonella pathogens grow and replicate in the infected host?

Inside Phagocytes

What are leukocidins?

Molecules that are capable of destroying phagocytes

How does a capsule help certain bacteria evade detection by the immune system?

The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.

If mosquitoes are the mode of transmission for West Nile virus, why did the students in Bill's virology class focus on finding the virus in the dead birds rather than collecting mosquitoes to examine?

The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.

How are immune cells able to detect foreign pathogens?

They are able to detect structures on the surfaces of foreign cells that are not found in the host.

How do superantigens enable pathogens to hide from the immune system if they actually stimulate the immune system?

They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.