PC1208: Paenibacillus Thiaminolyticus Meningitis and Diffuse Cerebritis in a Healthy Two Week Old Term Infant

Introduction: The genus Paenibacillus comprises bacterial species relevant to humans, animals, plants, and the environment. They are a facultatively anaerobic endospore-forming, rod-shaped bacteria thought to be Gram-positive to Gram-variable. Within agriculture, they have been known to promote crop growth. Recent literature suggests that Paenibacilli has become a rare human pathogen with potentially fatal outcomes, particularly in immunocompromised adults and premature infants. Here we present a case report of Paenibacillus meningitis in a previously healthy two week old infant with a more favorable outcome.

Case Description: A two week old term infant presented to the emergency department with a one-day history of fever, decreased activity, and decreased oral intake. On initial examination, the infant was febrile, tachycardic, and reported to be sleepy but easily arousable. A comprehensive sepsis work-up was initiated, which demonstrated bandemia and cerebrospinal fluid cytology findings concerning for infection. She was started on antibiotics and admitted to the pediatric floor. Subsequently, the infant developed upper extremity twitching; confirmed to be seizures on electroencephalogram. She was started on anti-epileptic medication. Blood culture and CSF culture at 24 hours showed gram negative rods; later reported to be pan-sensitive Paenibacillus thiaminolyticus species. MRI brain showed diffuse early cerebritis with focal petechial hemorrhages seen in frontal lobes and left parieto-occipital lobe with surrounding edema. The patient remained vitally stable and demonstrated clinical improvement on antibiotics and anti-epileptic medication. Repeat cerebrospinal fluid culture was negative and she was discharged home to continue anti-epileptic medication. At one month follow up, the patient continued to do well but did have electroencephalogram findings consistent with multifocal epilepsy.

Discussion: Paenibacillus species are occasionally isolated from wounds, gingiva, blood, urine, and cerebrospinal fluid. In healthy adults, Paenibacillus is reported as a contaminant not requiring treatment. Paenibacillus thiaminolytis is very rarely reported in infants. A study in Uganda involving infants with post infection hydrocephalus found that Paenibacillus thiaminolytis infection was presumably involved in the clinical course of the patients. Another case of Paenibacillus thiaminolytis in the United States was reported in a premature infant who had an unfavorable outcome. There continues to be paucity of literature on Paenibacillus infection which has thus far only been reported on case-to-case basis.

Conclusion: Paenibacillus species is a rare infection in infants, and despite early recognition of illness, adequate antibiotic coverage and aggressive supportive care, providers should be aware that extensive brain damage and neurologic deficits may be a consequence of this infection.