CEA Nursing Practice Exam

Which gram-negative rod is least likely to cause a urinary tract infection?

1. Escherichia Coli

2. Proteus Mirabilis

3. Enterococcus

4. Klebsiella Oxytoca

The correct answer is: Enterococcus

The correct answer is Enterococcus, and this is due to the specific characteristics of the bacteria involved in urinary tract infections (UTIs). Enterococcus is a genus of bacteria that, while capable of causing infections in certain circumstances, is not the primary pathogen associated with UTIs. It is more commonly implicated in infections such as endocarditis and can occasionally be involved in more complicated urinary tract infections, particularly in hospitalized or immunocompromised patients, but it is less frequent in otherwise healthy individuals. In contrast, Escherichia coli is the leading cause of uncomplicated UTIs, accounting for a significant majority of cases. Proteus mirabilis can also be a known cause of UTIs, often associated with indwelling catheters, while Klebsiella oxytoca can contribute to both complicated and uncomplicated urinary infections. Therefore, these gram-negative rods have a strong association with urinary tract infections, whereas Enterococcus is less commonly the cause in typical scenarios. This distinction highlights the bacteriological dynamics of UTIs and demonstrates why Enterococcus stands out as the least likely of the options presented to cause these infections.