Question 1

Which of the following is a major virulence factor of Enterohemorrhagic Escherichia coli (EHEC) O157:H7 that allows it to cause severe disease in humans?

Accepted Answer

Presence of virulence plasmids encoding for fimbriae, adhesins, and exotoxins

Question 2

A patient presents with bloody diarrhea after eating undercooked ground beef. Laboratory tests confirm infection with E. coli O157:H7. Which complication should the physician be most concerned about developing?

Accepted Answer

Hemolytic uremic syndrome, which can lead to kidney failure

Question 3

Which of the following best describes the transmission route for urinary tract infections (UTIs) caused by Escherichia coli?

Accepted Answer

Contamination of the urinary tract with fecal bacteria

Question 4

A urine sample from a patient with suspected UTI shows $$\u003e100,000$$ bacteria per milliliter. Which clinical feature does this finding most directly support?

Accepted Answer

Cloudiness of urine due to bacteriuria

Question 5

Which of the following is NOT a recommended prevention strategy for urinary tract infections in females?

Accepted Answer

Unnecessarily using spermicides

Question 6

Syphilis, caused by Treponema pallidum, is characterized by a primary stage lesion called a chancre. Which of the following best describes this lesion?

Accepted Answer

A firm, round, painless sore that heals without treatment

Question 7

A patient with untreated syphilis develops neurological symptoms and gummas 15 years after initial infection. Which stage of syphilis is this?

Accepted Answer

Tertiary stage

Question 8

Which of the following statements about Chlamydia trachomatis is TRUE?

Accepted Answer

It has a unique developmental cycle with elementary and reticulate bodies

Question 9

Trachoma, caused by Chlamydia trachomatis, is a leading cause of blindness worldwide. What is the primary mechanism by which trachoma leads to blindness?

Accepted Answer

Scarring of the conjunctiva causing the eyelashes to turn in and abrade the cornea

Question 10

Which of the following is a common clinical feature of urinary tract infections that distinguishes them from other infections?

Accepted Answer

Dysuria, or painful burning urination

Question 11

A sexually active woman presents with frequent urination and cloudy urine. Which organism is most likely responsible for her symptoms?

Accepted Answer

Escherichia coli

Question 12

Which of the following is a recommended first-line antibiotic for treating uncomplicated urinary tract infections?

Accepted Answer

Trimethoprim/sulfamethoxazole

Question 13

Which of the following groups is at increased risk for urinary tract infections?

Accepted Answer

Elderly men with prostatic enlargement

Question 14

Which virulence factor allows Treponema pallidum to spread between cells during infection?

Accepted Answer

Hyaluronidase

Question 15

A newborn develops conjunctivitis after passing through the birth canal of an infected mother. Which pathogen is most likely responsible?

Accepted Answer

Chlamydia trachomatis

Question 16

Which of the following best explains why spermicides increase the risk of urinary tract infections?

Accepted Answer

They kill normal urinary tract flora, allowing colonization by pathogenic bacteria

Question 17

Which of the following is a key difference between the elementary body (EB) and reticulate body (RB) forms of Chlamydia trachomatis?

Accepted Answer

EB is infectious and survives outside cells; RB is noninfective and replicates inside cells

Question 18

A patient with secondary syphilis presents with a rash on the palms and soles and swollen lymph nodes. What is the most likely next stage if the infection is left untreated?

Accepted Answer

Latent stage, which is clinically inactive and can last for years

Question 19

Which of the following is a major cause of nontraumatic blindness worldwide and is associated with poor hygiene and sanitation?

Accepted Answer

Trachoma caused by Chlamydia trachomatis

Bacterial Pathogens: Epidemiology, Virulence, Clinical Features, and Prevention part 2

Guida di studio - Domande di pratica

Study guide - Flashcard