Bacterial Pathogenesis Flashcards
. A 26-year-old woman visits her physician because of an unusual
vaginal discharge. On examination, the physician observes a
thin, homogeneous, white-gray discharge that adheres to the
vaginal wall. The pH of the discharge is 5.5 (normal, <4.3). On
Gram stain, many epithelial cells covered with gram-variable
rods are seen. Bacterial vaginosis is diagnosed. Which normal genital flora microorganisms is greatly decreased in bacterial vaginosis?
Lactobacillus Species
Certain microorganisms are never considered to be members of
the normal flora. They are always considered to be pathogens.
Which one of the following organisms fts into that category?
(A) Streptococcus pneumoniae
(B) Escherichia coli
(C) Mycobacterium tuberculosis
(D) Staphylococcus aureus
(E) Neisseria meningitidis
Mycobacterium tuberculosis
A 9-year-old girl develops fever and severe pain on the right side
of her throat. On examination, redness and swelling in the right
peritonsillar area are seen. A peritonsillar abscess is diagnosed.
The most likely organisms to be cultured from this abscess are
Normal oral nasal flora
. A 70-year-old man with a history of diverticulosis of the sigmoid colon experiences a sudden onset of severe left lower quadrant abdominal pain. Fever develops. The severe pain gradually
subsides and is replaced by a constant aching pain and marked
abdominal tenderness. A diagnosis of probable ruptured diverticulum is made, and the patient is taken to the operating room.
The diagnosis of ruptured diverticulum is confirmed, and an abscess next to the sigmoid colon is found. Te most likely
bacteria to be found in the abscess are
Mixed normal gastrointestinal flora
Antimicrobial therapy can decrease the amount of susceptible
bowel fora and allow proliferation of relatively resistant colonic
bacteria. Which one of the following species can proliferate and
produce a toxin that causes diarrhea?
Clostridium difficile
Which one of the following microorganisms can be part of the
normal vaginal flora and cause meningitis in newborns?
(A) Candida albicans
(B) Corynebacterium species
(C) Staphylococcus epidermidis
(D) Urea plasma urealyticum
(E) Group B streptococci
Group B streptococci
Dental plaque and periodontal disease can be thought of as a continuum of what type of physiological process?
Biofilm formation
. Which one of the following microorganisms is closely associated with dental caries? (A) Candida albicans (B) Streptococcus mutans (C) Prevotella melaninogenica (D) Neisseria subfava (E) Staphylococcus epidermidis
(B) Streptococcus mutans
Anaerobic bacteria such as Bacteroides fragilis occur in the sigmoid
colon in a concentration of about 1011/g of stool. At what concentration do facultative organisms such as Escherichia coli occur?
10raisedto8/g
Streptococcus pneumoniae can be part of the normal fora of5–40% of people. At what anatomic site can it be found?
Nasopharynx
Hundreds of phylotypes have been identifed in the human
stomach; however, the only microorganism that has been
shown to persist is?
Helicobacter pylori
Resident flora is commonly found in the
Urethra
Resident flora is absent from the
Synovial fuid
A 65-year-old woman was admitted with squamous cell carcinoma of the cervix. She underwent extensive gynecologic surgery and was maintained postoperatively on broad-spectrum
intravenous antibiotics. The patient had a central venous catheter placed on the day of surgery. Beginning 3 days postoperatively, the patient became febrile. On day 8, cultures of blood
and of the tip of the central line both grew gram-positive
organisms that were ovoid and reproduced by budding. Which
of the following microorganisms is most likely responsible for
the patient’s condition?
Candida albicans
The most likely portal of entry for the organism in Question
14 is
During placement of the central line
