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Different Behavior and Response of Staphylococcus Epidermidis and Streptococcus Pneumoniae to a Ventriculoperitoneal
Vahid Heidari1, Zohreh Habibi, Ahmadreza Hojjati Marvasti
1Department of Neurosurgery, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran.
Background:
Pneumococcal shunt infection is a rare event. There is no consensus on the therapeutic management of this kind of shunt infection according to literature reviews, and it seems to be different from infection with Staphylococcus epidermidis. We studied 2 shunted patients with pneumococcal meningitis, both of whom were treated with only antibiotics. The management of these cases seems to be different from that of shunt catheter infection due to these bacteria. We conducted a laboratory study to show the different behavior of pneumococcus compared to S. epidermidis regarding shunt catheter colonization.
Materials And Methods:
S. epidermidis and Streptococcus pneumoniae bacteria isolated from the cerebrospinal fluid of meningitis patients were incubated in sterile media. Forty-five segments of shunt catheter from silicone material were placed in 45 separate media of S. epidermidis and pneumococcus. Then each catheter was washed and cultured in blood chocolate agar growth medium in separate petri dishes via the roll plate method. The dishes were extracted from the incubator and the colony count was calculated after 72 h.
Results:
The colony count was obviously different between the 2 bacteria groups, with a higher count related to S. epidermidis dishes. The colony count of the pneumococcal petri dishes was 25-35,000 (mean 14,337) and for dishes with S. epidermidis it was 14,000-100,000 (mean 50,125) (p = 0.001).
Conclusion:
The adherence of pneumococcus to shunt catheters seems to be much less than that of S. epidermidis, which produced a very low colony count when incubated with the catheter in the medium culture. S. pneumoniae meningitis in shunted patients can be managed successfully with only antibiotics. This approach can prevent problems related to the several additional surgeries required for shunt removal, a new shunt insertion, and the management of high intracranial pressure.
Insights
Pneumococcal shunt infections show less bacterial adherence to catheters than Staphylococcus epidermidis, suggesting antibiotics alone may successfully treat Streptococcus pneumoniae meningitis in shunted patients.
Area of Science:
- Neuroscience
- Infectious Diseases
- Biomaterials Science
Background:
- Pneumococcal shunt infection is rare and its management differs from Staphylococcus epidermidis infections.
- Literature reviews indicate no consensus on treating pneumococcal shunt infections.
- This study investigates the distinct behavior of Streptococcus pneumoniae compared to Staphylococcus epidermidis in shunt catheter colonization.
Purpose of the Study:
- To compare the adherence of Streptococcus pneumoniae and Staphylococcus epidermidis to silicone shunt catheters.
- To evaluate the efficacy of antibiotic-only treatment for pneumococcal meningitis in shunted patients.
Main Methods:
- Isolated Streptococcus pneumoniae and Staphylococcus epidermidis from cerebrospinal fluid.
- Incubated 45 silicone shunt catheter segments with each bacterium in sterile media.
- Cultured washed catheter segments and quantified bacterial colonies after 72 hours.
Main Results:
- Significantly lower bacterial colony counts for Streptococcus pneumoniae (mean 14,337) compared to Staphylococcus epidermidis (mean 50,125) (p = 0.001).
- Demonstrated reduced adherence of pneumococcus to shunt catheters.
- Observed a higher adherence of S. epidermidis to the shunt material.
Conclusions:
- Pneumococcus exhibits significantly less adherence to shunt catheters than S. epidermidis.
- Antibiotic monotherapy may be a successful treatment for Streptococcus pneumoniae meningitis in shunted patients.
- This approach avoids risks associated with shunt removal and replacement surgeries.
