Question

Women with urinary tract infections caused by E. coli are generally treated with a course of antibiotics. A common complication of the antibiotic treatment is the occurrence of a vaginal yeast infection caused by Candida albicans, an organism that is normally present in very low numbers in the human vaginal tract. This complication occurs because:

A) The E. coli infection damages the reproductive epithelium, causing a breach in the tight junctions and allowing invasion by the Candida albicans.
B) The E. coli infection induces adhesion molecule expression on the reproductive epithelium, allowing attachment of the yeast.
C) The antibiotic treatment kills all strains of fungi present in the reproductive tract, except the Candida albicans.
D) The E. coli infection causes gastrointestinal distress leading to diarrhea.
E) The antibiotics kill many of the commensal organisms in the reproductive tract, allowing overgrowth of the fungus.

Answer 1

The common complication of a vaginal yeast infection after antibiotic treatment for a UTI is due to the antibiotics killing the commensal organisms, allowing Candida albicans to overgrow. The natural balance is disrupted, allowing the opportunistic fungus to cause symptoms of a yeast infection.

Step-by-step explanation:

Women with urinary tract infections (UTIs) caused by Escherichia coli (E. coli) are generally treated with a course of antibiotics. A common complication of antibiotic treatment is the occurrence of a vaginal yeast infection caused by Candida albicans, an organism that is normally present in very low numbers in the human vaginal tract. This complication occurs because the antibiotics kill many of the commensal organisms in the reproductive tract, allowing overgrowth of the fungus.

Lactobacilli in the vagina typically inhibit the growth of other organisms, including bacteria and Candida, but disruptions, such as antibiotic therapy, can allow Candida to increase in numbers, resulting in a yeast infection. Symptoms of this infection include inflammation, pruritus (itching), a thick white or yellow discharge, and odor. Candida albicans is commonly found in the normal, healthy microbiota and typically only causes disease in the female reproductive tract under conditions that compromise the host's defenses.