The inhabitants of a group of small villages in rural sub-Saharan Africa experienced an epidemic of meningitis. Ten percent of the people died, most of them younger than the age of 15 years. The microorganism that most likely caused this epidemic was
(A) Streptococcus agalactiae (group B)
(B) Escherichia coli K1 (capsular type 1)
(C) Haemophilus influenzae serotype b
(D) Neisseria meningitidis serogroup A
A 9-year-old boy presented to the clinic with a urethral discharge for the past 24 hours. Neisseria gonorrhoeae was cultured from the specimen and found to be β-lactamase positive and resistant to high levels (≥32 μg/mL) of tetracycline. Which of the following statements about these antimicrobial resistance factors is correct?
(A) β-lactamase production and high-level resistance to tetracycline are both mediated by genes on plasmids.
(B) Whereas β-lactamase production is mediated by a gene on the bacterial chromosome, high-level tetracycline resistance is mediated by a gene on a plasmid.
(C) Whereas β-lactamase production is mediated by a gene on a plasmid, high-level tetracycline resistance is mediated by a gene on the bacterial chromosome.
(D) β-lactamase production and high-level resistance to tetracycline are both mediated by genes on the bacterial chromosome.
A 6-year-old boy develops a fever and headache. He is taken to the emergency department, where he is noted to have a stiff neck, suggesting meningeal irritation. A lumbar puncture is done, and culture of the cerebrospinal fluid grows Neisseria meningitidis serogroup B. Which of the following should be considered for his family (household) members?
(A) No prophylaxis or other steps are necessary.
(B) They should be given Neisseria meningitidis pilin vaccine.
(C) They should be given Neisseria meningitidis serogroup B polysaccharide capsule vaccine.
(D) They should be given rifampin prophylaxis.
(E) They should be given sulfonamide prophylaxis.
An 18-year-old woman who reports unprotected sex with a new partner 2 weeks previously develops fever and left lower quadrant abdominal pain with onset in association with her menstrual period. On pelvic examination in the emergency department, she has bilateral tenderness when the uterus is palpated. A mass 2–3 cm in diameter is felt on the left, suggestive of tubo-ovarian abscess. Subsequently, Neisseria gonorrhoeae is cultured from her endocervix. The diagnosis is gonococcal pelvic inflammatory disease. A common sequela of this infection is:
(C) Uterine fibroid tumors
(E) Vaginal-rectal fistula
A 38-year-old vice squad police officer comes to the emergency department with a chief complaint expressed as follows: “I have disseminated gonococcal infection again.” He is correct. Cultures of his urethra and knee fluid yield Neisseria gonorrhoeae. He has previously had five episodes of disseminated gonococcal infection. The patient should be evaluated for
(A) Selective IgA deficiency
(B) A polymorphonuclear cell chemotactic defect
(C) Deficiency of a late-acting complement component C5, C6, C7, or C8
(D) Absent lymphocyte adenosine deaminase activity
(E) Myeloperoxidase deficiency
Which of the following individuals should routinely receive vaccination with the conjugate meningococcal vaccine?
(A) A healthy young adolescent entering high school
(B) A healthy child entering kindergarten
(C) A 60-year-old man with insulin-dependent diabetes
(D) A healthy 40-year-old technician who works in a cancer research laboratory
(E) A 65-year-old woman with coronary artery disease
A 25-year-old sexually active woman presents with purulent vaginal discharge and dysuria 7 days after having unprotected sexual intercourse with a new partner. Of the choices below, what is the most sensitive diagnostic method for determining the likely etiologic agent?
(B) An enzyme immunoassay
(C) Bacterial culture on selective media
(D) A nucleic acid amplification test
What is the currently recommended treatment for gonococcal urethritis in men who have sex with men in the United States?
(A) Single dose of an oral fluoroquinolone
(B) Seven days of oral doxycycline
(C) Ceftriaxone given intramuscularly as a single dose
(D) Spectinomycin given intramuscularly as a single dose
(E) Seven days of oral amoxicillin
Which of the following cell components produced by Neisseria gonorrhoeae is responsible for attachment to host cells?
(D) Outer membrane porin protein
A 60-year-old man with severe chronic lung disease presents with fever, cough productive of purulent sputum, and worsening hypoxemia. A sputum sample is collected, and the specimen is sent promptly to the laboratory. Microscopic examination of a Gram stain reveals numerous polymorphonuclear leukocytes and predominately gram-negative diplococci that are both intracellular and extracellular. The organism grows well on 5% SBA and chocolate agar and is positive for butyrate esterase. What is the most likely organism causing this man’s illness?
(A) Neisseria gonorrhoeae
(C) Moraxella catarrhalis
(D) Haemophilus influenzae
(E) Neisseria meningitidis
One major advantage of the conjugate meningococcal vaccines compared with the polysaccharide vaccine is
(A) Stimulation of mucosal secretory IgA
(C) A T cell–dependent response to vaccine is induced
(D) Inclusion of serogroup B
A 25-year-old woman presents with septic arthritis of the knee. The fluid aspirate grows a gram-negative diplococcus on chocolate agar after 48 hours of incubation. The isolate is oxidase positive and oxidizes glucose but not maltose, lactose, or sucrose. You suspect infection with:
(A) Neisseria meningitidis
(C) Moraxella catarrhalis
(D) Neisseria gonorrhoeae
All of the following are virulence factors associated with N gonorrhoeae except
(E) A thick polysaccharide capsule
The prevalence of gonococcal infections increased between 2009 and 2012.
A useful test to differentiate Moraxella catarrhalis from saprophytic neisseriae in respiratory samples is:
(C) Growth on 5% sheep blood agar