Antibiotic Resistance in Diabetic Patient
Antibiotic Resistance Develops in a Diabetic Patient Case Study
Vancomycin-resistant Staphylococcus aureus (VRSA) was isolated from the exit site of a dialysis catheter in a 40-year-old diabetic with a history of peripheral vascular disease, chronic renal failure, and chronic foot ulcers. A few months earlier, the patient’s gangrenous toe had been amputated. Following that surgery, the patient developed bacteremia with methicillin-resistant S. aureus from an infected hemodialysis graft. Vancomycin, rifampin, and graft removal successfully treated the infection.
A few months later, when the catheter exit site infection appeared, the area was cultured and the catheter removed, successfully treating the infection. A week later, the patient’s chronic foot ulcer again appeared infected. Vancomycin-resistant Enterococcus faecalis (VRE) and Klebsiella oxytoca were cultured from the ulcer. The patient recovered after wound care and systemic treatment with trimethoprim/sulfamethoxazole.
Analysis of the VRSA isolate revealed that it contained the van A gene for vancomycin resistance and the mec A gene for oxacillin resistance.
–How do you think the Staphylococcus aureus strain ended up with the gene for vancomycin resistance?
–What is one possible mechanism for genetic transfer of antibiotic resistance from one organism to another?
