Staphylococcal Aureus Infection, Surgical Site Infection (SSI)
Conditions
Keywords
MRSA, Biofilm, Probiotics, Antimicrobial resistance
Brief summary
Staphylococcus aureus are Gram-positive cocci that asymptomatically colonize the skin and mucosal surfaces of approximately 20-30% of healthy individuals . Although they commonly exist as a harmless commensal organisms, S. aureus are one of the most clinically significant opportunistic pathogens, causing a wide range of community and healthcare-associated infections. These infections vary from superficial skin and soft tissue infections to severe invasive diseases, including bacteremia, infective endocarditis, pneumonia, osteomyelitis, and device-associated infections .
Detailed description
The global emergence and dissemination of methicillin-resistant Staphylococcus aureus (MRSA) have further complicated the treatment of these infections because of its resistance to β-lactam antibiotics and many other antimicrobial agents, leading to increased morbidity, mortality, prolonged hospitalization, and substantial healthcare costs worldwide. The pathogenicity of Staphylococcus aureus is largely attributed to its diverse virulence factors, which facilitate bacterial adhesion, tissue invasion, immune evasion, and persistence within the host. These virulence determinants include microbial surface components recognizing adhesive matrix molecule, extracellular enzymes, cytotoxins, superantigens, and immune evasion proteins, all of which contribute to successful colonization and disease progression . Among these virulence factors, biofilm formation is considered one of the most important determinants of S. aureus pathogenicity. Biofilms are highly organized bacterial communities embedded within a self-produced extracellular polymeric matrix (EPS). This matrix enhances bacterial adherence to both biotic and abiotic surfaces while protecting the bacteria from host immune defenses and antimicrobial agents . Consequently, biofilm-associated infections are often characterized by persistent infection, failure in treatment , and increased antimicrobial resistance, Therefore, disrupting biofilm formation has become a key target for developing novel therapeutic strategies. Probiotics have attracted increasing attention as promising addition to conventional antimicrobial therapy because of their ability to inhibit pathogenic microorganisms, interfere with biofilm formation, and modulate bacterial virulence . Many of these beneficial effects are mediated by probiotic-derived cell-free supernatants (CFS), which contain a variety of bioactive compounds, including organic acids, bacteriocins, hydrogen peroxide, biosurfactants, and other antimicrobial metabolites. Several studies have demonstrated that probiotic-derived CFS can inhibit Staphylococcus aureus biofilm formation and suppress the expression of virulence-associated genes, thereby reducing bacterial pathogenicity . Surgical site infections (SSIs) represent a major healthcare burden in Egyptian hospitals, with reported prevalence rates ranging from 9% to 26% among postoperative patients .
Interventions
* Direct smear with Gram stain to identify the morphology of Staphylococcus aureus. * culture of the samples on different culture media such as nutrient agar, blood agar, and Mannitol salt agar.
biochemical reactions: catalase test will be done to confirm diagnosis of Staphylococcus aureus.
Antibiotic sensitivity test will be done using different antibiotics according to CLSI 2026.
Assessment of the expression of selected biofilm-related genes (icaA and fnbA) and antibiotic resistance-related genes (mecA and femA) using quantitative real-time PCR (qRT-PCR) before and after treatment with probiotic cell-free supernatant (CFS).
Sponsors
Study design
Eligibility
Inclusion criteria
* Patients of any age diagnosed with postoperative SSIs. * Clinical isolates from SSIs identified as MRSA.
Exclusion criteria
* Any microorganism isolated from SSIs other than MRSA. * Prior administration of postoperative antibiotics
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The effect of Probiotic cell-free supernatant (CFS) on the expression of the biofilm-associated genes icaA and fnbA in clinical MRSA isolates.. | December 2026- to March 2027 |
| The number of clinical Staphylococcus aureus isolates from SSIs and determine their antimicrobial susceptibility patterns to identify methicillin-resistant Staphylococcus aureus (MRSA). | September 2026 to January 2027 |
| The effect of Probiotic cell-free supernatant (CFS) on the expression of the antibiotic resistance-associated genes mecA and femA in clinical MRSA isolates | March 2027 to June 2027 |