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[Infection of a cerebrospinal fluid shunt system by Bacillus circulans and Bacillus larvae]
A Roncoroni1, M Rivas, J Smayevsky
1CEMIC, Buenos Aires, Argentina.
Abstract:
A two episodes case of CSF ventriculo-atrial shunt infection due to B. circulans and B. larvae is presented. B. circulans was first isolated from 4 blood cultures and CSF (shunt valve tap). The patient showed a brain damage syndrome reversible with antibiotic treatment. Lethal toxin production was demonstrated for the B. circulans strain in a mouse model. This strain was found to be a variant of Gordon's description as it produced urease and was tolerant to 7% NaCl. The patient recovered after cefotaxime, cotrimoxazole and rifampicin treatment. A second infection due to B. larvae was detected two months later. The shunt system was removed due to obstruction and a scanning electron microscopy study was performed. Confluent masses of white blood cells and rods were observed on the inner surface of the catheter. As for as we know, this is the first case of human infection due to B. larvae.
Insights
This study reports two rare cases of cerebrospinal fluid (CSF) shunt infections in a single patient, first by Bacillus circulans and then by Bacillus larvae. Both infections were successfully treated with antibiotics, highlighting the importance of identifying these unusual pathogens.
Area of Science:
- Infectious Diseases
- Microbiology
- Neurosurgery
Background:
- Central nervous system (CNS) infections pose significant challenges, particularly in patients with cerebrospinal fluid (CSF) shunts.
- Bacillus species are uncommon causes of human infections, especially in the context of neurosurgical devices.
Observation:
- A patient experienced two distinct episodes of shunt infection: first with Bacillus circulans, causing reversible brain damage, and subsequently with Bacillus larvae.
- Bacillus circulans strain exhibited urease production and high salt tolerance, deviating from known descriptions.
- Scanning electron microscopy revealed extensive bacterial and host cell presence within the removed shunt catheter.
Findings:
- Bacillus circulans infection was successfully treated with cefotaxime, cotrimoxazole, and rifampicin.
- The second infection, caused by Bacillus larvae, marks the first reported case of human infection by this organism.
- The study demonstrates the potential for lethal toxin production by Bacillus circulans in a murine model.
Implications:
- This case series expands the known spectrum of Bacillus species causing human infections, particularly shunt-related ones.
- Early identification and appropriate antibiotic therapy are crucial for managing these rare but potentially severe infections.
- Further research into the pathogenicity and treatment of Bacillus species in CNS infections is warranted.