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Polymicrobial and Monomicrobial Infections after Spinal Surgery: A Retrospective Study to Determine which Infection
Shaoqiang Liu1,2, Qiang Qi1, Zhongqiang Chen1
1Department of Orthopedics, Peking University Third Hospital, Beijing, China.
Study Design:
A retrospective clinical review.
Purpose:
To investigate the difference in clinical manifestations and severity between polymicrobial and monomicrobial infections after spinal surgery.
Overview Of Literature:
Surgical site infections (SSIs) after spinal surgery are a major diagnostic and therapeutic challenge for spinal surgeons. Polymicrobial infections after spinal surgery seem to result in poorer outcomes than monomicrobial infections because of complementary resistance to antibiotics. However, comparison of the clinical manifestations and severity between polymicrobial and monomicrobial infections are limited.
Methods:
Sixty-seven patients with SSIs after spinal surgery were studied: 20 patients with polymicrobial infections and 47 with monomicrobial infections. Pathogenic bacteria identified were counted and classified. Age, sex, and body mass index were compared between the two groups to identify homogeneity. The groups were compared for clinical manifestations by surgical site, postoperative time to infection, infection site, incisional drainage, incisional swelling, incisional pain, neurological signs, temperature, white blood cell count, and the percentage of neutrophils. Finally, the groups were compared for severity by hospital stay, number of rehospitalizations, number of debridements, duration of antibiotics administration, number of antibiotics administered, and implant removal.
Results:
Polymicrobial infections comprised 29.9% of SSIs after spinal surgery, and most polymicrobial infections (70.0%) were caused by two species of bacteria only. There was no difference between the groups in terms of clinical manifestations and severity. In total, 96 bacterial strains were isolated from the spinal wounds: 60 strains were gram-positive and 36 were gram-negative pathogenic bacteria. Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Enterobacter cloacae were cultured in order of the frequency of appearance.
Conclusions:
Most polymicrobial infections were caused by two bacterial species after spinal surgery. There was no difference in clinical manifestations or severity between polymicrobial and monomicrobial infections.
Insights
This study found no significant differences in clinical manifestations or severity between polymicrobial and monomicrobial surgical site infections following spinal surgery. Most polymicrobial infections were caused by only two bacterial species.
Area of Science:
- Spinal surgery outcomes
- Infectious disease research
- Bacteriology
Background:
- Surgical site infections (SSIs) post-spinal surgery pose diagnostic and therapeutic challenges.
- Polymicrobial SSIs may lead to worse outcomes due to antibiotic resistance, but comparative data are limited.
Purpose of the Study:
- To investigate differences in clinical manifestations and severity between polymicrobial and monomicrobial infections after spinal surgery.
Main Methods:
- Retrospective review of 67 patients with SSIs post-spinal surgery (20 polymicrobial, 47 monomicrobial).
- Comparison of clinical manifestations (e.g., pain, swelling, fever) and severity indicators (e.g., hospital stay, rehospitalizations, debridements).
- Bacterial identification and classification, including Gram-positive and Gram-negative strains.
Main Results:
- Polymicrobial infections constituted 29.9% of SSIs, with 70% involving two bacterial species.
- No significant differences were observed in clinical manifestations or severity between polymicrobial and monomicrobial infection groups.
- Commonly isolated bacteria included *Staphylococcus aureus*, *Staphylococcus epidermidis*, *Escherichia coli*, and *Enterobacter cloacae*.
Conclusions:
- The majority of polymicrobial spinal SSIs are caused by two bacterial species.
- Clinical presentation and severity do not differ significantly between polymicrobial and monomicrobial infections after spinal surgery.
