[Campbell Biology P.633] A patient presents with symptoms of a sexually transmitted infectio... | Practice Question

A patient presents with symptoms of a sexually transmitted infection STI , and laboratory tests reveal gram-negative bacteria that are obligate intracellular parasites and unusually lack a typical peptidoglycan layer. Based on the provided information, which bacterium is the most likely causative agent?

  • A: *Neisseria gonorrhoeae*
  • B: *Vibrio cholerae*
  • C: *Chlamydia trachomatis*
  • D: *Treponema pallidum*

Explanation

The section on Chlamydias explicitly states: 'These parasites can survive only within animal cells' obligate intracellular , 'The gram-negative walls of chlamydias are unusual in that they lack peptidoglycan,' and 'One species, Chlamydia trachomatis , is... the most common sexually transmitted disease in the United States.' This description perfectly matches the patient's symptoms and laboratory findings.