What is the most common cause of prosthetic graft infection: Staphylococcus (Staph) epidermidis, Staphylococcus (Staph) aureus, Escherichia (E) coli, or Streptococcus (Strep) faecalis?

From the Guidelines

The most common cause of prosthetic graft infection is Staphylococcus epidermidis (option a). This coagulase-negative staphylococcal species is particularly problematic for prosthetic materials because it produces a biofilm that adheres to synthetic surfaces, as noted in a study published in the International Journal of Oral Science 1. The biofilm formation allows the bacteria to colonize the graft material, making these infections difficult to treat with antibiotics alone. S. epidermidis is part of normal skin flora, which explains why it commonly contaminates prosthetic grafts during implantation. While Staphylococcus aureus is also a significant cause of graft infections, particularly in early postoperative infections, S. epidermidis remains the predominant pathogen overall, as supported by guidelines from the Infectious Diseases Society of America 1.

Some key points to consider in the management of prosthetic graft infections include:

• The importance of prompt diagnosis and treatment to prevent complications and improve outcomes
• The use of appropriate antibiotics, such as vancomycin, and surgical intervention, which may include graft removal in severe cases
• Prevention strategies, including meticulous surgical technique, appropriate perioperative antibiotic prophylaxis, and minimizing operative time
• The potential for biofilm formation and the challenges it poses in treating these infections, as discussed in a study published in Clinical Infectious Diseases 1

It's worth noting that while other organisms, such as Escherichia coli and Streptococcus faecalis, can also cause prosthetic graft infections, S. epidermidis is the most common and problematic pathogen in this context, as highlighted in a study published in Circulation 1. Therefore, Staphylococcus epidermidis (option a) is the most likely cause of prosthetic graft infection.

From the Research

Prosthetic Graft Infection Causes

• The most common cause of prosthetic graft infection is Staphylococcus epidermidis, as stated in studies 2, 3, 4, 5
• Staphylococcus aureus is also a common cause of prosthetic graft infection, as mentioned in study 4
• Other causes of prosthetic graft infection, such as Escherichia coli and Streptococcus faecalis, are not as commonly cited in the provided studies

Common Pathogens

• Staphylococcus epidermidis is the causative organism in over 50% of prosthetic graft infection cases, as highlighted in study 3
• Staphylococcus aureus is also a significant pathogen, with methicillin-sensitive Staphylococcus aureus being the second most common pathogen isolated in study 4

Prevention and Treatment

• Sound surgical technique, use of prophylactic antibiotics, and avoidance of a groin incision are emphasized as important factors in preventing graft infection, as stated in study 3
• The use of mupirocin-soaked grafts and perioperative intraperitoneal vancomycin prophylaxis can be effective in preventing prosthetic graft infection, as shown in studies 2, 5