Medical imaging Early and massive tissue necrosis is a specific feature of<unk>  brain infection. The early stage of the disease predominates in the white matter, causing cerebritis; the later stage is marked with necrotic cavities in multiple locations. The cavities are initially square in shape and not tense, but when pus forms and collects in these cavities, they tend to become more rounded in shape; a persisting cavity leads to septated ventriculitis that may result in multicyctic hydrocephalus. Early, cerebritis is seen, and multiple large cavities can be seen in the late stage of the disease; abscesses formation, contraction of the cavities, and hydrocephalus due to ventriculitis are observed in the late follow up. Pathology Macroscopic findings include purulent exudates, opaque leptomeninges (thinning of meninges), pus, and ventriculitis/ ependymitis. Microbiology In samples collected from cerebrospinal fluid,<unk>  grows well on an any ordinary medium; they produce unpigmented, colorless mucoid colonies. If incubated for 24 hours in other media such as indole, citrate, and adonitol,<unk>  will be positive, hydrogen sulfide negative in Kligers’ iron agar, negative results in lactose, salicin, and sucrose broth as well. Histology<unk>  may be identified in the walls of congested vessels, presence of the cavities resulting from the infection do not develop well-formed fibrotic wall. Differential diagnosis The differential diagnosis of<unk>  brain abscesses can be confused with other related diseases, so diagnostic imaging is important to confirm this bacterium. The significant feature of<unk>  is the necrotic cavity which cannot be misidentified as earlier ischemic or hemorrhagic insult or other mass lesions; congential/neonatal tumors are uncommon (choroid plexus papillomas, craniopharyngiomas, teratomas); even when they present, they are different from the inflammatory ring of a cerebral infection. Early cerebritis should not be mistaken for normal, immature white matter, nor for cicatricial leukomalacia.
Citrobacter koseri
Escherichia coli
Enterobacter cloacae
Klebsiella oxytoca
Enteroaggregative Escherichia coli
Escherichia coli O121
Escherichia coli O157:H7
Proteus mirabilis