Spectra of central nervous system melioidosis

Multi-systemic melioidosis in a patient with type 2 diabetes in non-endemic areas: A case report and review of literature

BACKGROUND

Melioidosis, an infectious disease caused by Burkholderia pseudomallei (B. pseudomallei), occurs endemically in Southeast Asia and Northern Australia and is a serious opportunistic infection associated with a high mortality rate.

CASE SUMMARY

A 58-year-old woman presented with scattered erythema on the skin of her limbs, followed by fever and seizures. B. pseudomallei was isolated successively from the patient's urine, blood, and pus. Magnetic resonance imaging showed abscess formation involving the right forehead and the right frontal region. Subsequently, abscess resection and drainage were performed. The patient showed no signs of relapse after 4 months of follow-up visits post-treatment.

CONCLUSION

We present here a unique case of multi-systemic melioidosis that occurs in non-endemic regions in a patient who had no recent travel history. Hence, it is critical to enhance awareness of melioidosis in non-endemic regions.

Cycle-Inhibiting Factor Is Associated with Burkholderia pseudomallei Invasion in Human Neuronal Cells

Burkholderia pseudomallei is a pathogenic bacterium that causes human melioidosis, which is associated with a high mortality rate. However, the underlying mechanisms of B. pseudomallei pathogenesis are largely unknown. In this study, we examined the infection of human neuronal SH-Sy5y cells by several clinically relevant B. pseudomallei strains. We found that all tested B. pseudomallei strains can invade SH-Sy5y cells, undergo intracellular replication, cause actin-tail formation, and form multinucleated giant cells. Additionally, a deletion mutant of B. pseudomallei cycle-inhibiting factor (cif) was constructed that exhibited reduced invasion in SH-Sy5y cells. Complementation of cif restored invasion of the B. pseudomallei cif-deleted mutant. Our findings enhance understanding of B. pseudomallei pathogenicity in terms of the virulence factor Cif and demonstrate the function of Cif in neurological melioidosis. This may eventually lead to the discovery of novel targets for treatment and a strategy to control the disease.

L. AK, Rohitha CS, Elenjickal GX, T. V. S, Thomas SG. Cerebral venous sinus thrombosis as a complication of cranial melioidosis – a rare case report

Cerebral venous sinus thrombosis is a rare complication of cranial melioidosis. We report a case of an adult male who presented with skull osteomyelitis, transverse sinus thrombosis and multiple brain abscesses. His blood cultures grew Burkholderia pseudomallei . The patient finally succumbed after multiple recurrences of the infection despite surgical excision of the osteomyelitic bone and the recommended antibiotic treatment. The management of cerebral venous sinus thrombosis in patients with cranial melioidosis is discussed along with a brief review of the literature.

Isolated Myelitis and Intramedullary Spinal Cord Abscess in Melioidosis-A Case Report

Neuromelioidosis is a severe tropical infection with high morbidity and mortality. Isolated myelitis is an extremely rare manifestation of melioidosis which may evade diagnosis. We report a 69-year-old diabetic male patient who presented with acute flaccid paraplegia and longitudinally extensive myelitis and no systemic symptoms. MRI of spinal cord showed lower dorsal cord and conus T2 hyperintensity and microabscesses with dural enhancement. The diagnosis was clinched with blood culture growing Burkholderia pseudomallei. He rapidly developed colitis, septicemia and multiorgan dysfunction and succumbed to the illness in spite of antibiotics and aggressive supportive care. The case highlights that melioidosis should be considered as a differential diagnosis of infectious myelitis, especially in the tropics. Presence of a neutrophilic blood and cerebrospinal fluid picture and microabscesses in spinal cord are important diagnostic clues. The outcome is dismal unless the diagnosis is considered early in the disease course and managed expeditiously with sensitive antibiotics.

Cerebral abscess and calvarial osteomyelitis caused by Burkholderia pseudomallei in a renal transplant recipient

Melioidosis is an infection of humans caused by the saprophytic bacterium Burkholderia (previously Pseudomonas) pseudomallei. We present a patient of cerebral abscess and calvarial osteomyelitis caused by B. pseudomallei in a renal transplant recipient. We treated the patient with ceftazidime for 3 weeks, followed by trimethoprim-sulfamethoxazole (TMP-SMX) for 6 months. The superficial abscess reduced in size at the end of first month and subsided gradually. A repeat MRI showed reduction in intracranial abscess. The patient had no neurological deficit.

Fatal deep venous thrombosis and pulmonary embolism secondary to melioidosis in China: case report and literature review

BACKGROUND

Burkholderia pseudomallei is a gram-negative bacterium and the causative pathogen of melioidosis, which manifests a variety ranges of infection symptoms. However, deep venous thrombosis (DVT) and pulmonary embolism (PE) secondary to bacteremic melioidosis are rarely documented in the literature. Herein, we reported a fatal case of melioidosis combined with DVT and PE.

CASE PRESENTATION

A 54-year-old male construction worker and farmer with a history of diabetes was febrile, painful in left thigh, swelling in left lower limb, with chest tightness and shortness of breath for 4 days. He was later diagnosed as DVT of left lower extremity and PE. The culture of his blood, sputum and bone marrow samples grew B. pseudomallei. The subject was administrated with antibiotics (levofloxacin, cefoperazone/tazobactam, and imipenem) according to antimicrobial susceptibility testing and low molecular heparin for venous thrombosis. However, even after appropriate treatment, the patient deteriorated rapidly, and died 2 weeks after admission.

CONCLUSIONS

This study enhanced awareness of the risk of B. pseudomallei bloodstream infection in those with diabetes. If a patient has predisposing factors of melioidosis, when DVT is suspected, active investigation and multiple therapeutic interventions should be implemented immediately to reduce mortality rate.

Cranial Melioidosis Presenting as Osteomyelitis and/or Extra-Axial Abscess: Literature Review

BACKGROUND

Central nervous system (CNS) melioidosis is rare. Clinical presentations depend on the region of endemicity. Despite treatment, neurologic disease has relatively high mortality rates. Less than 80 cases of CNS involvement have been reported.

METHODS

A literature review was performed by searching online databases for melioidosis presenting as osteomyelitis or scalp/extra-axial abscess (OSEAA). In addition, 3 similar cases managed at my institute have been presented.

RESULTS

Including this report of 3 cases, 20 additional cases have been reported. Of these, 12 cases (60%) were from India. The mean age of patients was 45.5 years (range, 29-74 years), and none were in the pediatric age group. Patients in the fifth to sixth decades were most frequently affected. The male to female ratio was 5.3:1. Eleven patients had predisposing factors. Fever, headache, and scalp swelling were the most common features. Five cases had history of previous melioid infection. Seven cases had systemic disease. Debridement was performed in 11 cases. The average intensive phase treatment duration was 4.6 weeks (range, 2-8 weeks) and 5.5 months (range, 3-12 months) for the maintenance phase. Mean follow-up duration was 13.5 months (range, 2 weeks-40 months). Two deaths (10%) were reported, and 1 case of residual frontal abscess had relapse.

CONCLUSIONS

Cranial melioidosis presenting as OSEAA is associated with good outcome, in contrast with other neurologic presentations. Intensive phase for at least 2-3 weeks followed by maintenance phase for 3-6 months is the standard treatment, similar to other melioid presentations. A high degree of suspicion and accurate identification of the organism is crucial. Patients need to be monitored for recurrences, both clinically and radiologically.

Melioidosis with a subdural collection - a case report

BACKGROUND

Melioidosis is an infection caused by Burkholderia pseudomallei, which is more prevalent in the tropics and leads to significant morbidity and mortality. It characteristically produces widespread caseous lesions and abscesses, and can present with varied clinical manifestations. Melioidosis involving the central nervous system is uncommon.

CASE PRESENTATION

A 42-year-old Sri Lankan male with type 2 diabetes presented with a febrile illness of 6 days with headache and constitutional symptoms. Clinical examination was unremarkable. Four days later, he developed focal seizures involving the left leg and numbness of the left side. Initial laboratory investigations were suggestive of a bacterial infection. Blood culture was reported as positive for a Pseudomonas species, which was resistant to gentamicin. Contrast enhanced CT and MRI scans of the brain showed a subdural collection in the right fronto-temporo-parietal region with possible abscess formation. Melioidosis antibody testing using indirect hemagglutination method was reactive with a titre more than 1/10,240. He was treated with intravenous meropenem and oral co-trimoxazole for 8 weeks (Intensive phase). The subdural collection was managed conservatively, and seizures were treated with oral antiepileptics. At 7 weeks, follow-up contrast enhanced MRI showed improvement of the subdural collection, and inflammatory markers had normalized. He was discharged after 8 weeks, and treated with oral co-trimoxazole and doxycycline for 6 months (eradication phase). At 6 months follow-up, the patient is asymptomatic.

CONCLUSIONS

Cerebral melioidosis is an unusual presentation of melioidosis where the diagnosis can be easily missed. Knowledge of the protean manifestations of melioidosis is of paramount importance in order to detect and treat this potentially fatal infection appropriately, especially in tropical countries where the disease is endemic.

The Tunnel Sign Revisited: A Novel Observation of Cerebral Melioidosis Mimicking Sparganosis

The tunnel sign has been described as a specific feature of cerebral sparganosis. We present a case of a 55-year-old gentleman found to have cerebral melioidosis and with initial imaging mimicking the appearance of sparganosis. This suggests that the tunnel sign in brain abscesses may be specific for infection by Burkholderia Pseudomallei, Spirometra Mansoni or Listeria Monocytogenes.

Neuromelioidosis Masquerading as Acute Demyelinating Encephalomyelitis

BACKGROUND

Neuromelioidosis is a rare conduction, which is difficult to diagnose and treat.

CASE CHARACTERISTICS

Preadolescent girl presenting with prolonged fever, acute ascending paralysis and encephalopathy.

OUTCOME

Neuromelioidiosis was confirmed on brain biopsy culture. Patient improved with an intensive antibiotic regimen.

MESSAGE

Neuromelioidosis can mimic acute demyelinating encephalomyelitis clinically and radiologically.

Central nervous system melioidosis in the pediatric age group: review

PURPOSE

Melioidosis is a potentially fatal infectious disease caused by Burkholderia pseudomallei. Neurologic involvement in pediatric age group is very rare, and only a handful of cases have been reported in literature. We sought to provide a systematic review of pediatric neurologic melioidosis.

METHODS

Literature review was performed to analyze reported cases of pediatric neurologic melioidosis (≤16 years) by searching online database (PubMed/MEDLINE).

RESULTS

Twenty-seven cases were analyzed. Mean age was 6.7 years (range 2 days-14 years) and around 50% were older children (>5 years). Cranial nerve palsies and fever were most common presenting features. Major manifestations were meningoencephalitis in 16 (59%) and cerebral abscesses in eight (29%) cases. Abscesses were mostly located in parietal lobe. Among older children, abscesses were common than meningeal disease, while being converse for neonates. Mean follow-up duration was 11.5 months. Ten cases showed good to excellent outcome, while eight cases had fair (incomplete recovery) outcomes. The overall mortality rate was 18.5% (5/27) and tends to decrease with age. Among the five deaths, 4 (80%) had septicemia or pneumonia.

CONCLUSIONS

Pediatric neurologic melioidosis is very rare. Meningoencephalitis is the most common presentation. Mortality is the highest in neonates. Ceftazidime appears to be the drug of choice in intensive phase, although the best drug in maintenance phase cannot be commented upon, especially in very young children.

Neuromelioidosis: a series of seven cases in Hainan province, China

Melioidosis, which is caused by Burkholderia pseudomallei, is predominately a disease of tropical climates and is especially widespread in south-east Asia and northern Australia. Melioidosis affecting the central nervous system has a low incidence but a high mortality. We present seven cases of neuromelioidosis and analyze the disease characteristics and imaging features. Typical clinical features of this disease included high fever and headache. Five patients had an irregular fever with a temperature ≥ 39℃. Peripheral blood leukocytes and the neutrophil ratio were raised in all patients. On computed tomography and magnetic resonance imaging the disease mainly manifested as intracerebral single or multiple nodules, as well as ring and flake-like enhancements with rapid lesion progression. This study demonstrated the importance of imaging examination in the clinical evaluation and diagnosis of neuromelioidosis.

Central Nervous System Melioidosis Mimics Malignancy: A Case Report and Literature Review

BACKGROUND

Central nervous system (CNS) melioidosis is notorious because of the difficulty in bacteria eradication and the destruction of brain structures. Early manifestation of CNS melioidosis mimics malignancy or stroke. We present a case of CNS melioidosis that initially manifested as malignancy.

CASE DESCRIPTION

A 30-year-old man presented with sudden onset of left limb weakness and seizure. Computed tomography of the brain showed a low-density lesion over the right parietal lobe, and magnetic resonance imaging showed a well-enhanced lobulated lesion. Neuronavigation-guided open surgery was performed but failed to find a malignancy. The patient presented 3 days later with sudden loss of consciousness, pupil dilation, and high fever. Emergent craniectomy was performed for severe right hemisphere swelling with midline shift. After craniectomy, pus was found in the previous operative field. Burkholderia pseudomallei was cultured from pus and blood samples 1 week after collection. The brain lesion developed into an organized abscess and led to mass effect and ventriculitis. Extraventricular drainage and débridement was performed repeatedly accompanied by systemic and intraventricular antibiotic administration. After 4 months of treatment, the patient achieved a complete consciousness recover while left hemiparesis.

CONCLUSIONS

CNS melioidosis requires accurate pathogen identification and appropriate long-term antibiotic treatment for eradication of bacteria and prevention of relapse. Débridement and adequate drainage provide better infection control and outcome.

An intriguing case of locked jaw secondary to melioidosis

A 56-year-old woman presented with fever, pain and restriction of movement of the right temporomandibular joint. She was premorbidly diagnosed to have type 2 diabetes mellitus and rheumatoid arthritis. Local examination revealed a poorly demarcated severely tender, erythematous swelling in the right preauricular region. All haematological and biochemical investigations were within normal limits. MRI of the neck revealed the presence of a masticator space infection with intramuscular abscess involving the masseter and the temporalis muscles along with intracranial extension. Osteomyelitic changes were detected in the right mandibular condyle, temporal bone and in the temporomandibular joint. Melioidosis was suspected due to this unique clinical presentation of an abscess at an unusual and atypical site. Blood cultures identified the Gram-negative bacilli Burkholderia pseudomallei, which established the diagnosis of Melioidosis. Remarkable improvement was attained with antibiotics meropenem and cotrimoxazole, deferring the need for any surgical intervention.

Neuromelioidosis: Craniospinal MRI Findings in Burkholderia pseudomallei Infection

PURPOSE

To investigate magnetic resonance imaging (MRI) findings of central nervous system (CNS) infection with Burkholderia pseudomallei.

METHODS

Retrospective analysis of 10 patients (5 male and 5 female, age range from 13 to 69 years) with CNS melioidosis confirmed on culture of blood, sputum, cerebrospinal fluid, brain biopsy, and postmortem brain tissue. Clinical data were collected and MRI brain and/or spine were independently reviewed.

RESULTS

Seven patients with brain parenchymal or intramedullary spinal cord lesions demonstrated rim-enhancing microabscesses with propensity for white matter tracts including the corticospinal tracts, corpus callosum, and cerebellar peduncles. Three of these 7 patients also showed thickening and enhancement of the trigeminal nerves with contiguous spread to brain stem trigeminal nuclei. Three patients had isolated extraaxial disease with findings including meningeal enhancement, extradural abscess, skull osteomyelitis, and scalp abscess.

CONCLUSION

Spread of microabscesses along white matter tracts and frequent trigeminal nerve involvement are unique imaging characteristics of CNS melioidosis. These findings may provide insight into potential mechanisms for B. pseuodomallei entry into the CNS through direct axonal transport in cranial nerves bypassing the blood brain barrier. Prompt recognition of the neuroimaging features of this potentially fatal infection may allow for early microbiological culture and treatment.

Induction of mouse melioidosis with meningitis by CD11b+ phagocytic cells harboring intracellular B. pseudomallei as a Trojan horse

BACKGROUND

Approximately 3-5% of patients with melioidosis manifest CNS symptoms; however, the clinical data regarding neurological melioidosis are limited.

METHODS AND FINDINGS

We established a mouse model of melioidosis with meningitis characterized by neutrophil infiltration into the meninges histologically and B. pseudomallei in the cerebrospinal fluid (CSF) by bacteriological culturing methods. As the disease progresses, the bacteria successively colonize the spleen, liver, bone marrow (BM) and brain and invade splenic and BM cells by days 2 and 6 post-infection, respectively. The predominant cell types intracellularly infected with B. pseudomallei were splenic and BM CD11b(+) populations. The CD11b(+)Ly6C(high) inflamed monocytes, CD11b(+)Ly6C(low) resident monocytes, CD11b(+)Ly6G(+) neutrophils, CD11b(+)F4/80(+) macrophages and CD11b(+)CD19(+) B cells were expanded in the spleen and BM during the progression of melioidosis. After adoptive transfer of CD11b populations harboring B. pseudomallei, the infected CD11b(+) cells induced bacterial colonization in the brain, whereas CD11b(-) cells only partially induced colonization; extracellular (free) B. pseudomallei were unable to colonize the brain. CD62L (selectin) was absent on splenic CD11b(+) cells on day 4 but was expressed on day 10 post-infection. Adoptive transfer of CD11b(+) cells expressing CD62L (harvested on day 10 post-infection) resulted in meningitis in the recipients, but transfer of CD11b(+) CD62L-negative cells did not.

CONCLUSIONS/SIGNIFICANCE

We suggest that B. pseudomallei-infected CD11b(+) selectin-expressing cells act as a Trojan horse and are able to transmigrate across endothelial cells, resulting in melioidosis with meningitis.

Cerebral melioidosis for the first time in the western hemisphere

This report is the first published case of cerebral melioidosis in the western hemisphere. In this paper the authors review the literature on neurological melioidosis and its presentation and treatment in endemic areas, describe the clinical course of this unique case of a presentation of the disease with cranial abscess in the US, review the pathological and radiological findings associated with this seminal case, and put forth recommendations for recognizing and treating possible future instances of the disease within the western hemisphere.

Melioidosis and the vacuum-assisted closure device: a rare cause of a discharging neck wound, and a new approach to management

OBJECTIVE

We report a case of melioidosis presenting as a discharging neck abscess, and we describe the use of a vacuum-assisted closure device in its management.

METHOD

We report the case of a 44-year-old, Afro-Caribbean woman with melioidosis. We also present the results of a literature search using the search terms 'melioidosis', 'Burkholderia pseudomallei' and 'vacuum-assisted closure device'.

RESULTS

Microbiological analysis identified the causative organism as being the bacterium Burkholderia pseudomallei, and its antimicrobial sensitivities to imipenem and ciprofloxacin. A vacuum-assisted closure device was used to manage the patient's melioidosis of the neck; we believe this is the first report of such treatment.

CONCLUSIONS

Melioidosis is rare in the UK and western world; however, exposure can occur during travel to endemic areas. We therefore draw attention to this infection as part of the differential diagnosis of a neck abscess. We propose the use of vacuum-assisted closure devices as useful adjuncts to the management of discharging neck wounds.