49 terms

MICROBIOLOGY Chapter 14 & 15

Gram-negative septic shock results from the following events. What is the second step?
LPS is released from gram-negative bacteria
Figure 14.1 shows the incidence of influenza during a typical year. Which letter on the graph indicates the endemic level?
Which of the following is NOT a membrane-disrupting toxin?
A-B toxin
Patients developed inflammation a few hours following eye surgery. Instruments and solutions were sterile, and the Limulus assay was positive. The patients' inflammation was due to
Injectable drugs are tested for endotoxins by
The Limulus amoebocyte lysate test.
Symptoms of protozoan and helminthic diseases are due to
all of the above
Which of these infections can cause septicemia?
Focal infection
Which of the following is NOT a method of avoiding host antibodies?
Membrane-disrupting toxins
Which of the following can contribute to postoperative infections?
all of the above
Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that
Streptococcal colonization is necessary for periodontal disease
Pseudomonas bacteria colonized the bile duct of a patient following his liver transplant surgery. This is an example of a
Nosocomial infection
One effect of washing regularly with antibacterial agents is the removal of normal microbiota. This can result in
increased susceptibility to disease
Situation 14.1
During a 6-month period, 239 cases of pneumonia occurred in a town of 300 people. A clinical case was defined as fever ≥39°C lasting >2 days with three or more symptoms (i.e., chills, sweats, severe headache, cough, aching muscles/joints, fatigue, or feeling ill). A laboratory-confirmed case was defined as a positive result for antibodies against Coxiella burnetii. Before the outbreak, 2000 sheep were kept northwest of the town. Of the 20 sheep tested from the flock, 15 were positive for C. burnetii antibodies. Wind blew from the northwest, and rainfall was 0.5 cm compared with 7 to 10 cm during each of the previous 3 years.

Situation 14.1 is an example of
a zoonosis
Antibiotics can lead to septic shock if used to treat
Gram-negative bacterial infections
Most pathogens that gain access through the skin
Enter through hair follicles and sweat ducts.
A nosocomial infection is
Acquired during the course of hospitalization.
A needlestick is an example of which portal of entry?
parenteral route
Mechanical transmission differs from biological transmission in that mechanical transmission
doesn't involve specific diseases
Which of the following is a fomite?
a hypodermic needle
Which of the following organisms causes the most severe disease?
Can't tell
Which of the following does NOT contribute to a pathogen's invasiveness?
The most likely mode of transmission of pneumonic plague between humans is
Droplet transmission
Endotoxins are
Part of the gram-negative cell wall.
Koch's postulates don't apply to all diseases because
Not all diseases are caused by microorganisms.
Symptoms of disease differ from signs of disease in that symptoms
Are changes felt by the patient.
Septic shock due to gram-positive bacteria is caused by
Pseudomonas aeruginosa produces a two-part exotoxin. The most likely pathologic effect of this toxin is
Inhibition of protein synthesis
Influenza transmitted by an unprotected sneeze is an example of
Droplet transmission
A cell wall can increase a bacterium's virulence because cell wall lipid A
is toxic
Botulism is caused by a proteinaceous exotoxin; therefore it can easily be prevented by
Boiling food prior to consumption.
A commensal bacterium
may be an opportunisitic pathogen
Which of the following CANNOT be used for adherence?
cell membrane mannose
Poliovirus is ingested and gains access to tissues by which portal of entry?
Mucous membrane
Koch observed Bacillus anthracis multiplying in the blood of cattle. What is this condition called?
The science that deals with when diseases occur and how they are transmitted is called
Emergence of infectious diseases can be due to all of the following EXCEPT
Microbes trying to cause disease
The major significance of Koch's work was that
Microorganisms cause disease
Which organism most easily causes an infection?
Legionella pneumophila ID50=1
Transient microbiota differ from normal microbiota because transient microbiota
Are present for a relatively short time
Thirty-two people in San Francisco who ate jackfish caught at Midway Island developed malaise, nausea, blurred vision, breathing difficulty, and numbness from 3 to 6 hours after eating. The most likely cause of this food intoxication is
A needlestick is an example of
Which of the following diseases is NOT spread by droplet infection?
The most frequently used portal of entry for pathogens is the
Mucous membrane of the respiratory tract
A sexually transmitted disease is an example of
Direct contact
Which of the following cytopathic effects is cytocidal?
Release of enzymes from lysosomes
Gastroenteritis acquired from roast beef is an example of
Vehicle transmission
Which of the following does NOT contribute to the virulence of a pathogen?
All of the above contribute to a pathogen's virulence
Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed,
Polypeptide B would not be able to enter the cells
Plague transmitted by a flea is an example of