Cryptococcal pathogenic mechanisms: a dangerous trip from the environment to the brain

Cryptococcus neoformans is an opportunistic pathogenic yeast that causes serious infections, most commonly of the central nervous system (CNS). C. neoformans is mainly found in the environment and acquired by inhalation. It could be metaphorically imagined that cryptococcal disease is a "journey" for the microorganism that starts in the environment, where this yeast loads its suitcase with virulence traits. C. neoformans first encounters the infected mammalian host in the lungs, a site in which it must choose the right elements from its "virulence suitcase" to survive the pulmonary immune response. However, the lung is often only the first stop in this journey, and in some individuals the fungal trip continues to the brain. To enter the brain, C. neoformans must "open" the main barrier that protects this organ, the blood brain barrier (BBB). Once in the brain, C. neoformans expresses a distinct set of protective attributes that confers a strong neurotropism and the ability to cause brain colonisation. In summary, C. neoformans is a unique fungal pathogen as shown in its ability to survive in the face of multiple stress factors and to express virulence factors that contribute to the development of disease.

Actinomicosis diseminada con compromiso de sistema nervioso central / Disseminated actinomycosis with central nervous system involvement

Resumen La actinomicosis diseminada es muy infrecuente, así como la afección del sistema nervioso central (SNC) asociada, con mortalidad de hasta 28%. Sus manifestaciones pueden ser similares a cuadros infecciosos de otras etiologías, por lo que el conocimiento de la entidad aumenta la sospecha clínica y permite brindar un tratamiento oportuno. Se presenta el caso clínico de un adulto con edema en una extremidad superior como manifestación de una tromboflebitis y una lesión abscedada axilar, en que se confirmó una infección por actinomicetos. Presentó una diseminación hematógena con compromiso de SNC, de evolución fatal.

Actinomycosis is very rare, as well as the central nervous system (CNS) condition associated with it, presenting a mortality up to 28%. Its manifestations could be similar to infectious conditions from other etiologies, thus, having a better understanding of the entity increases clinical suspicion and also it can provide a timely treatment. The clinical case of an adult with edema in an upper extremity is presented as a manifestation of thrombophlebitis and an abscessed axillary lesion, in which actinomycetes infection was confirmed. He presented a haematogenous spread with CNS involvement, with fatal ending.

Diagnostic and prognostic value of procalcitonin for early intracranial infection after craniotomy

Intracranial infection is a common clinical complication after craniotomy. We aimed to explore the diagnostic and prognostic value of dynamic changing procalcitonin (PCT) in early intracranial infection after craniotomy. A prospective study was performed on 93 patients suspected of intracranial infection after craniotomy. Routine peripheral venous blood was collected on the day of admission, and C reactive protein (CRP) and PCT levels were measured. Cerebrospinal fluid (CSF) was collected for routine biochemical, PCT and culture assessment. Serum and CSF analysis continued on days 1, 2, 3, 5, 7, 9, and 11. The patients were divided into intracranial infection group and non-intracranial infection group; intracranial infection group was further divided into infection controlled group and infection uncontrolled group. Thirty-five patients were confirmed with intracranial infection after craniotomy according to the diagnostic criteria. The serum and cerebrospinal fluid PCT levels in the infected group were significantly higher than the non-infected group on day 1 (P<0.05, P<0.01). The area under curve of receiver operating characteristics was 0.803 for CSF PCT in diagnosing intracranial infection. The diagnostic sensitivity and specificity of CSF PCT was superior to other indicators. The serum and CSF PCT levels have potential value in the early diagnosis of intracranial infection after craniotomy. Since CSF PCT levels have higher sensitivity and specificity, dynamic changes in this parameter could be used for early detection of intracranial infection after craniotomy, combined with other biochemical indicators.

Neurolisteriosis en adultos: a propósito de seis casos clínicos / Neurolisteriosis in adults: report of six clinical cases

INTRODUCCION: Listeria monocytogenes tiene una especial predilección por infectar el sistema nervioso central y sus cubiertas meningeas. Afecta a pacientes que se encuentran en edades extremas de la vida, pacientes con deficiencia en su inmunidad celular y adultos sanos. La forma mas común de manifestarse es la meningitis aguda, aunque puede expresarse como cerebritis, encefalitis de tronco (romboencefalitis), y excepcionalmente mielitis. CASUISTICA: Se presentan y comentan seis casos clinicos de neurolisteriosis, cinco en adultos sanos, con sus hallazgos imagenológicos y licuorales. RESULTADOS: Tres de los pacientes se presentaron como meningitis aguda, uno como meningoencefalitis, otro como cerebritis y el restante como romboencefalitis. Se destaca el carácter turbio o ligeramente turbio del líquido cefalo-raquideo (LCR), la glucorraquia normal detectada en tres de los casos y el diagnostico realizado en cinco de los casos por cultivo del LCR. Se comenta la resonancia magnética singular del caso de la romboencefalitis con microabscesos en tronco. Todos los pacientes tuvieron evolución satisfactoria con tratamiento antibiotico. CONCLUSION: La neurolisteriosis debe ser un diagnostico a tener en cuenta no solo en pacientes inmunocomprometidos o en edades extremas de la vida. Debe también tenerse en cuenta en pacientes adultos jóvenes sanos procedentes de regiones donde las condiciones sanitarias son precarias y no existe un adecuado control en la elaboración de alimentos.

Clinical profile of neurobrucellosis--a report on 12 cases from Bikaner (north-west India).

OBJECTIVE: To study the spectrum of neurobrucellosis in a prospective study at Bikaner which is supposed to be uncommon in India. METHOD: This study was done on admitted patients of brucellosis from June 1996 to June 1999 in whom the diagnosis was done by history of exposure to animals, fever and arthralgia and demonstration of brucella antibody titres in serum 1:160. CSF examination was done in all the patients. All cases were treated by combination of doxycycline 100 mg twice daily, rifampicin 900 mg daily for 6-8 weeks and injection streptomycin 0.75 to 1 gm i.m. per day for initial 14 days. Detailed neurological examination and antibody titres of serum and CSF again measured at the end of treatment. RESULTS: Twelve out of 92 patients revealed evidence of neurobrucellosis in which four cases were of meningoencephalitis, two cases of myelitis leading to spastic paraparesis, five cases of polyradiculoneuropathy and one case of polyneuroradiculomyeloencephalopathy. The treatment regimen used was associated with a high cure rate and significant reduction in antibody titres in serum and CSF. CONCLUSION: Neurobrucellosis is an uncommon but serious manifestation affecting central and peripheral nervous system. The clinical profile of the disease mimicks closely to commonly seen neurological infective diseases like tubercular meningitis, viral encephalitis, aseptic meningitis, cerebral malaria and viral encephalopathy. Serum and CSF testing for brucella antibody titre is an important test for the diagnosis. Blood culture is not an ideal test for neurobrucellosis because of low yield and longer time required for the diagnosis. High degree of suspicion is prudent for the diagnosis. High degree of cure rate can be achieved by treatment with present regimen in a disease which is otherwise having high mortality and morbidity.