Antibiogram and Biofilm Formation of Bacteria Causing Prosthetic Joint Infections Isolated From Assiut University Hospital

Antibiogram and Biofilm Formation of Bacteria Causing Prosthetic Joint Infections Isolated From Assiut University Hospital

1. Setting of antibiogram in orthopedic department
2. Evaluate the production of biofilm in bacteria isolated from specimens phenotypically and genotypically.

Increased use of total joint arthroplasties will naturally result in a related increase in the number of prosthetic joint infections (PJIs).

PJI is a disastrous complication of orthopedic surgery, frequently leading to prolonged morbidity and increased mortality. Moreover, therapy for PJI is associated with enormous costs.

PJI results from numerous factors that lead to inability of periprosthetic immune cells to protect implant surfaces and tissues from bacterial colonization.

The most destabilizing factor is the ability of bacteria to adhere to and survive on virtually all natural and synthetic surfaces.

Once firmly attached to the surface of an implant, the microorganisms initiate "biofilm" formation, which is a complex of microbial cells embedded in an extracellular matrix composed of proteins, extracellular DNA, and exopolysaccharides, providing protection for bacteria and making them extremely resistant to the immune system and antibiotic.

An ineffective empiric antibiotic regimen can be harmful to patients while unnecessary broad-spectrum antibiotics lead to increased resistance. However, healthcare providers often select an antibiotic regimen before bacterial antibiotic sensitivities are available.

The Clinical and Laboratory of Standards Institute publishes the M39 Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test Data; Approved Guideline, which is a referenced guideline on how to create antibiograms.

The antibiogram has multiple uses, including providing guidance for empiric antibiotic therapy, monitoring changes in resistance over time, assisting in formulary decisions and supports antimicrobial stewardship programs to reduce multidrug resistant organisms and the risks of adverse drug events.

1. Inclusion criteria:

   • Age above 18 years old
   • no intraarticular surgery of the respective joint prior to the index surgery.

2. Exclusion criteria:

   • Age below 18 years old
   • If the patient had any intraarticular surgery prior to the primary arthroplasty in the respective joint.