Question

A 75-year-old man is admitted to the hospital for a severe urinary tract infection. A catheter is put in place and he is given a regimen of the appropriate antibiotics. The infection initially begins to respond to the antibiotics as the bacterial count of the urine sample shows a decrease in number. After a number of days in the hospital with the catheter still in place the bacterial numbers begin to rise again Assuming the type of antibiotic and the initial dosage was correct, what may be the explanation for the resurgence of the infection? What action(s) may be taken to bring the infection back under control without radically changing the antibiotic treatment in place?

Answer 1

The patient had been antibiotics for a long time. The bacteria causing the infection would be exposed to the antibiotic for a long time. Although, most bacteria would be killed by the antibiotic, a few bacteria would become resistant to the antibiotic. Antibiotic resistance is the ability of the bacteria to gain strategies to inactivate the antibiotic and be able to grow in presence of the antibiotic. These bacteria would grow over time. As the antibiotic is ineffective against the pathogen, there will be resurgence of the infection in the elderly patient.

Another major reason for resurgence of infection would be the catheter use. Hospitals are a reservoir of antibiotic resistant and other pathogenic strains of bacteria. These bacteria may enter the patient’s body via the catheter and cause reinfection or UTIs again. Using the same catheter for longer duration enhances the risk of reinfection. If the reinfection is due to the use of the same catheter, the catheter must be replaced periodically with new catheter. This will prevent fresh bacteria from invading the patient. Thus, the patient will now respond to the same antibiotics and will be cured. However, if the resurgence is due too antibiotic resistance, then just replacing the catheter may not work. In such cases, the antibiotic resistant bacteria must be isolated and characterized to identify which other antibiotics it is susceptible to it. These new antibiotics should be used to treat the infection.