Microbiology: A Systems Approach 4th Edition by Marjorie Kelly Cowan

Exercise 9

Critical thinking is the ability to reason and solve problems using facts and concepts. These questions can be approached from a number of angles and, in most cases, they do not have a single correct answer.
A farmer working on a piece of machinery gets his shirtsleeve caught in a moving piece of the equipment. His shirt is sliced, and a sharp blade covered in mud slices through his upper arm. He attempts to control the bleeding and immediately seeks medical attention. After 3 days, he develops a fever and his arm becomes extremely swollen and painful. Pulling back the bandages, he finds that the wound has become blackened and is leaking a bloody fluid. Microscopic analysis of the fluid reveals the presence of gram-positive bacilli.
a. Discuss what condition the patient is suffering from and the likely causative agent of this infection
b. Explain how the patient contracted this pathogenic microbe, and what virulence factors contributed to the pathogenesis seen at the wound site.
c. In addition to antibiotics, the physician prescribes hyperbaric therapy. Describe what this treatment involves and how it could be therapeutic to this patient.