Case Study – Chapter 21 Respiratory System Infectious
A 35-year-old Hispanic man presented to his family physician with fever which had persisted over 4 days. He had no history of fevers lasting this long. He had contracted tuberculosis when he was 17, but he had no family history of TB. He had taken no medications. He was a smoker and occasionally drank alcohol. He described to his doctor that 2 days prior, he suddenly developed chills and a sore throat with a fever (39.4 °C). A rapid test for influenza was negative. He was prescribed acetaminophen, however the fever persisted, and the man returned to his family physician the next day. Blood tests were done which showed that his white blood cell (WBC) count was elevated (>12,000 U/L) along with other tests that indicated inflammation. Although an oral cephalosporin was prescribed, his fever did not improve, and he was subsequently admitted to the hospital.
On admission, laboratory tests showed a high WBC count among other tests that showed inflammation. Rapid antigen tests for influenza, pneumococcus, and mycoplasma were negative. A sputum was also collected for culture for general and acid-fast bacilli. He was initially diagnosed with bronchopneumonia. Intravenous administration of levofloxacin (LVFX, 600 mg/day) and ampicillin/sulbactam (ABPC/SBT, 7 g/day) was started.
On the second day after admission, the patient’s temperature began to subside. The sputum smear was negative for acid-fast bacilli; however, catalase negative, beta-hemolytic, Gram-positive cocci in chains were detected in the blood cultures and sputum cultures. Other biochemical tests showed susceptibility to Taxo-A, CAMP test negative, positive PYR ,and negative Na hippurate.
- What is the diagnosis of this patient?
- Sepsis due to bacterial infection
- Bacterial bronchopneumonia and bacteremia
- Upper respiratory bacterial infection
- Generalized viral infection
- What agent do you think is causing this problem?
- Streptococcus pyogenes
- Staphylococcus agalactiae
- Streptococcus pneumoniae
- Mycobacterium tuberculosis
- One of the main differences between Streptococcus agalactiae and Streptococcus viridans is ___.
- They are both resistant to Taxo P.
- Hemolysis: S. agalactiae is beta hemolytic and S. viridans is alpha hemolytic.
- S. agalactiae is PYR positive whereas S. viridans is PYR negative.
- S. viridans has a capsule and S. agalactiae does not.
- Which group of antibiotics is most appropriate when treating this type of infection?
- Those that target cell wall synthesis such as penicillins and cephalosporins.
- Those that target protein synthesis such as neomycin.
- Those that target cell membrane integrity such as the polymyxins.
- Any of the above would be ideal.
- Complications that may arise due to an infection such as this include:
- Carditis, damaged heart valves, and glomerulonephritis