Cerebral abscess caused by Citrobacter koseri: A case report and review of the literature

To the Editors: Intracranial abscesses are uncommon in the newborn and have not been reported in a pair of twins. We describe Citrobacter meningitis complicated by multiple brain abscesses. These dizygotic twins were born by normal delivery, following induced labor at 37 weeks gestation. The babies were healthy at birth, weighing 2.18 kg and 2.30 kg. Perinatally, there were no prolonged ruptures of membranes, maternal fever, or illness. The twins were bottle-fed on formula and discharged home on day five. Twin 1 presented with a temperature of 37.8°C and a history of jerky movements on day 21 of life. Cerebrospinal fluid (CSF) analysis from lumbar puncture showed elevated white cell count of 5250 × 106/L (90% polymorphs, 10% lymphocytes). No organism was seen on Gram stain but culture yielded scanty growth of Citrobacter koseri. No organism was isolated from blood cultures. Twin 2 was asymptomatic but also had CSF obtained which showed 30 × 106/L white blood cells. No organism was isolated from the CSF or blood. Both babies were empirically treated with intravenous cefotaxime. Despite in vitro susceptibility of the organism to cefotaxime, both babies developed brain abscesses, evident on brain imaging at the end of the first week of treatment (Fig., Supplemental Digital Content 1, https://links.lww.com/INF/A260 and Fig., Supplemental Digital Content 2, https://links.lww.com/INF/A261). Intravenous meropenem was added in the second week but the abscesses continued to increase in size. On day 22 of antibiotic treatment the abscesses were drained by stereotactic needle aspiration; pus from the frontal abscesses in twin 2 grew Citrobacter koseri. Both babies remained clinically well throughout their hospitalization. Echocardiograms did not show cardiac abnormality to account for possible cerebral embolizsation. Four weeks of intravenous meropenem was completed and the babies were discharged home on further 3 months therapy for oral ciprofloxacin. At 4 months of age both babies were neurologically normal with resolution of cerebral abscesses on CT scans but persistence of a porencephalic cyst in twin 1 (Fig., Supplemental Digital Content 1, https://links.lww.com/INF/A260 and Fig., Supplemental Digital Content 2, https://links.lww.com/INF/A261). Citrobacter species are anaerobic Gram negative rods found infrequently as normal inhabitants of the intestinal tract of human and animals.1Citrobacter accounts for up to 4% of neonatal meningitis cases,2Citrobacter koseri (formerly Citrobacter diversus) being the most common species implicated.3 Newborns can acquire colonization at the time of passage through the birth canal of a colonized mother.4Citrobacter infection almost always results in meningitis but the mechanism for the neurotropism of this organism is not fully understood. Meningitis leads to intracerebral abscesses in 75% of cases.3 Case-fatality rate for Citrobacter meningitis of 30% has been observed, with at least 50% of surviving infants having neurologic sequelae.3 As our case demonstrates, bacteria can be cultured from abscesses despite systemic antibiotics, and also despite good concentration of antibiotics within the cavity.5 Neurosurgical management is therefore advocated: goals of abscess aspiration include removal of the mass effect, and reduction of the bacterial load thereby improving the local environment for systemic antibiotics to have their effect. This case report also highlights the increased risk of infection in the asymptomatic twin of an affected infant. Onajite Etuwewe, MB ChB, MRCPCH Department of Paediatric Infectious Diseases and Immunology Richa Kulshrestha, MB BS, MRCPCH Department of Neurology Meharpal Sangra, FRCS Department of Neurosurgery Andrew Riordan, MD, DTM&H, MRCP(UK), FRCPCH Department of Paediatric Infectious Diseases and Immunology Alder Hey Children's NHS Foundation Trust Liverpool, United Kingdom

SummaryBackgroundBrain abscesses are very rarely diagnosed in neonates, but if present, they are associated with a high risk of severe complications and mortality. In neonates, brain abscesses can be detected on transfontanelle ultrasonography, in which they appear as hyperechogenic lesions surrounded by a hypoechogenic border.Case ReportWe present a female neonate, born in the 28th week of gestation, with birth weight of 950 grams, who was born in an ambulance by spontaneous vaginal vertex delivery. No signs of infection were present until the 35th day of hospitalization, when a sudden and serious deterioration in the patient’s condition was observed due to late-onset sepsis. Cranial US, performed on the 40th day of life, revealed hyperechogenic lesions with a hypoechogenic halo in the right frontal lobe, which could correspond to brain abscesses. These lesions were caused by Citrobacter koseri septicaemia, identified by transfontanelle ultrasonography, and confirmed on magnetic resonance imaging. The patient recovered and was discharged on the 91th day of life (39 PCA) with a recommendation of permanent neurological surveillance.ConclusionsUltrasonography of the central nervous system can reveal inflammatory changes and developing brain abscesses. In neonates, magnetic resonance imaging should be performed as the method of choice for confirming brain abscesses.

Citrobacter koseri is a gram-negative bacillus that causes mostly meningitis and brain abscesses in neonates and infants. However, brain abscess caused by Citrobacter koseri infection in an adult is extremely rare, and only 2 cases have been described. Here, we reported a 73-year-old male presenting with a 3-week headache. A history of diabetes mellitus was noted. The images revealed a brain abscess in the left frontal lobe and pus culture confirmed the growth of Citrobacter koseri. The clinical symptoms improved completely postoperatively.

SummaryBrain abscess in neonates is rare but remains a severe, life-threatening complication of meningitis with significant morbidity and mortality. While Citrobacter koseri and Citrobacter freundii are commonly implicated in brain-abscess formation, Citrobacter sedlakii is an uncommon causative pathogen. To date, only two cases of neonatal brain abscess caused by C. sedlakii have been reported in the literature. Early diagnosis, timely surgical intervention and prompt antibiotic therapy are critical to achieving a favourable outcome. A third case of a C. sedlakii brain abscess in a preterm infant, presenting in 2024 to a tertiary-care hospital in Oman, is reported together with a brief review of the literature.

PP-129. Sepsis, meningitis and cerebral abscesses by Citrobacter koseri — Case report

Citrobacter koseri (C. koseri) is a Gram-negative, motile, non-spore-forming facultative anaerobic bacillus belonging to the Enterobacteriaceae family. C. koseri typically utilizes citrate as the sole carbon source and constitutes part of the normal gastrointestinal flora in humans and animals. As an opportunistic pathogen, C. koseri infections are mainly observed in neonates, elderly individuals, and immunocompromised hosts. C. koseri has been one of the main etiological agents of neonatal meningitis and cerebral abscess. In recent years, an increasing number of cases have been reported in adults with severe infections caused by C. koseri. Here, we report for the first time a clinical case of concurrent C. koseri intra-abdominal infection in a patient with severe asthma and provide a brief review of the relevant literature. With this report, we hope to increase awareness and alertness among clinicians to the possibility of concurrent infection of gut commensal bacteria in asthmatic patients requiring long-term oral corticosteroid administration.

Congenital dermal sinus(CDS)is a rare entity of spinal dysraphism, caused by the focal failure of disjunction leading to adhesion between the cutaneous and neural ectoderm. Some reports found that tumors, such as dermoid and epidermoid cysts, meningitis and subdural abscess are often complicated by CDS. A 1-year-old girl was referred to our department for CDS with a dermoid cyst complicated by brain and subdural abscesses. Diffusion weighted imaging and gadolinium-diethylenetriamine penta-aceticacid administration revealed ring-enhancing lesions, suggesting brain abscess, in the left temporal lobe, and subdural abscesses on the bilateral middle cranial bases. T1-and T2-weighted lumbar magnetic resonance imaging revealed CDS. With a preoperative diagnosis of CDS with brain and subdural abscesses, resection of CDS was performed after draining the brain abscess twice. The CDS extended into the spinal canal and it was completely exercised. We then performed sub-total resection of the dermoid cyst in the subdural space. Recent reports showed that dermoid cysts are related to CDS infection and deterioration of the infection, as seen in this case. Complication of dermoid cysts is an important consideration during CDS treatment. While the mechanism of the development of brain abscess in CDS patients has been unclear, this rare but important case revealed the mechanism to be the direct spread of inflammation via CDS.

Background:Intracranial infections are a rare complication of therapeutic neuroendovascular procedures.Case Description:We present a case of a 72-year-old female with multiple unilateral cerebral hemisphere abscesses after endovascular embolization of a right paraophthalmic aneurysm and also provide a comprehensive review of the literature on cerebral abscesses following neurovascular embolization.Conclusion:Infection following coil embolization of cerebral aneurysm is rare. However, it is likely to increase in the setting of increased used of neuroendovascular techniques in the future. Therefore, we suggest that extreme care is taken to ensure proper asepsis during embolization, and a high index of suspicion is maintained in patients with predisposing characteristics (large hemorrhage, ischemia, recurrent endovascular procedures, right-to-left shunt, and concomitant infection). Given the fact that the majority of abscesses occurred in patients who have had ruptured aneurysms, we suggest consideration is given to prophylactic intraprocedural intravenous antibiotics use as seen with open aneurysm treatment.

The authors reviewed six cases of multiple brain abscesses that were treated at King Khalid University Hospital (KKUH) over an eight year period. This represented 22% of the total brain abscesses treated during the same period. The series is unusual in that the infective pathogens were fungi (Fonsecaea pedrosoi) in two patients (33%) and an aerobic actinomycete (Nocardia asteroides) in one patient (16%). Two patients treated elsewhere with antibiotics empirically for one month died at three and 28 days following admission. The poor outcome was probably related t the delay in obtaining a microbiological diagnosis and commencing the appropriate antimicrobial therapy. The importance of early identification of the pathogen in patients with multiple brain abscesses is stressed.

Favorable outcome in cerebral abscesses caused by Citrobacter koseri in a newborn infant

Strongyloides Hyperinfection Syndrome causing fatal meningitis and septicemia by Citrobacter koseri

Nocardia brain abscess is relatively rare, accounting for about 1–2% of all brain abscesses, and its mortality rate is three times higher than of other types of bacterial brain abscesses; thus, early diagnosis and treatment are essential. Nocardia brain abscess generally occurs in immunodeficient patients. We report a case of Nocardia farcinica brain abscess in a multiple myeloma patient treated with proteasome inhibitor (bortezomib and ixazomib), cyclophosphamide, and corticosteroid. The patient was treated with ceftriaxone and trimethoprim-sulfamethoxazole, together with drainage of the brain abscess. Regular brain MRI follow-ups showed that intracranial lesions were gradually absorbed and improved.

BackgroundAn intracranial abscess secondary to medication‐related osteonecrosis of the jaw (MRONJ) is a rare condition that can spread to the skull through continuous structures.Case presentationA 71‐year‐old man with an intracranial epidural abscess caused by MRONJ in the maxilla. Because it is refractory to conservative treatment, inflammation had spread from sphenoid sinusitis, resulting in an intracranial abscess, and then antibiotic therapy and surgical drainage contributed to successful outcomes.ConclusionIntracranial abscess should be suspected when MRONJ extends to the adjacent structure, causing sudden headache and loss of consciousness. Early surgical intervention should be considered to reduce the risk of necrosis progressing.

Although cerebral otogenic abscess is a rare complication of chronic otitis media, it is the second most frequent complication after otogenic meningitis. This paper presents a case of cerebral otogenic abscess in the temporal lobe, in a patient who suffered from suppurative chronic otitis media.

The objective of our study is to report a rare complication of halo pin insertion associated with an epileptic seizure and brain abscess, and to discuss the diagnostic and therapeutic approach to its management. The treatment of unstable cervical spine injuries with a halo vest is an established procedure. Complications of pin penetration such as brain abscess and seizure are rare, and need to be urgently treated. Intracranial abscess and seizure associated with the use of the halo device is an unusual complication, and only a few cases have been reported in the literature. A 21-year-old male had a halo vest placed for the management of an odontoid type II fracture, which he sustained from a motor vehicle accident. Ten weeks after halo ring placement he complained of headaches which relieved by analgesics. After 2 weeks he was admitted at the emergency unit in an unconscious condition after a generalized tonic-clonic seizure. The halo pins were displaced during the seizure and were removed at his admission. No drainage was noted from the pin sites, and a Philadelphia cervical collar was applied. A brain CT and MRI revealed intracranial penetration of both posterior pins and a brain abscess in the right parietal lobe. Computed tomography of the cervical spine revealed stable fusion of the odontoid fracture. Cultures from the pin sites were negative; however, intravenous wide spectrum antibiotic treatment was administered to the patient immediately for 4 weeks followed by oral antibiotics for additional 2 weeks. Anti-epileptic medication was also started at his admission. The patient was discharged from the hospital in 6 weeks without symptoms, continuing anti-epileptic medication. On the follow-up visits he had fully recovered without any neurologic sequelae. In conclusion, complications of halo pin penetration are rare which need immediate intervention. Any neurologic or infectious, local or generalized, symptom need to be investigated urgently with available imaging techniques and treated promptly. Pin over-tightening may cause bone penetration and possible deep cranial infection with serious complications.