Microbial Growth and Urinary Tract Infections
Discouraging Growth
Read this case file, and complete the activities thatfollow.
Twenty-five-year-old Lisa visited the doctor’s office where Iwork, complaining of symptoms of a urinary tract infection. Hersymptoms included burning discomfort during urination and increasedfrequency of urination. Lisa has had numerous infections of theurinary tract within the past year for which she had beenprescribed antibiotics. Although the antibiotics cleared up theinfections quickly, Lisa was frustrated with the frequency of heruncomfortable urinary symptoms. Lisa asked me how she could preventurinary tract infections in the future. “Well,†I said. “There area few things you can do to decrease the number of infections you’vebeen having. The first is to make sure that you are drinking plentyof water. Another thing you can do is drink cranberry juice daily.There are chemicals in cranberry juice that block the attachment ofbacteria to the urinary tract. I’ve also read that the juice willhelp to create a more acidic environment in your bladder and willhopefully discourage the growth of bacteria.\"
Environmental factors influence the ability of microbes tosurvive and flourish. The body is normally maintained in a narrowpH range. Secretion of alkaline or acidic urine via the kidneys isone of the mechanisms used by the body to maintain normal pH. Mostbacteria involved in UTIs (urinary tract infections) make the urinemore alkaline by splitting urea into ammonia and other alkalineproducts. Cranberry juice keeps the urine acidic, making urine aless hospitable environment to bacteria attempting to gain afoothold in the bladder. Temperature is another environmentalfactor that influences microbial growth. Fever is thought to be thebody’s natural response to invasion by bacteria, or the body’s wayof making the internal environment less favorable for the growth ofbacteria. Fever raises the core body temperature as much as 2°C to3°C above normal. Some bacteria cannot tolerate highertemperatures, preferring a lower body temperature to multiply.
1. In the case, the patient is treated with antibiotics for herUTIs. Which type of organism must the physician suspect is causingher infections?
Bacterium
Virus
Fungus
Prion
2. The physician suggests that Lisa consume cranberry juice toprevent her recurrent UTIs, due to the fact that the juice makesthe urinary tract more ______.
alkaline
basic
acidic
mucoid
3. The physician informs Lisa that cranberry juice appears toreduce the ability of microbes to attach to the urinary tract.Which structures are used for attachment in microbes causingUTIs?
Cilia
Fimbriae
Endospores
Pseudopods
4. Most bacteria associated with UTIs make the urine more_______, creating an environment favorable for their growth.
viscous
alkaline
mucoid
acidic
5. Which of the following signs in the patient would indicatethat their body is fighting the microbes causing the UTI?
