Meningitis Research Today is a free monthly online journal that collates and summarizes the latest research about Meningitis, including details on viral, bacterial, spinal, symptoms, treatment.

A chromosomally integrated bacteriophage in invasive meningococci.

Bille E, Zahar JR, Perrin A, Morelle S, Kriz P, Jolley KA, Maiden MC, Dervin C, Nassif X, Tinsley CR

Institut National de la Santé et de la Recherche Medicale U570, Faculté de Médecine Necker, 75015 Paris, France.

Cerebrospinal meningitis is a feared disease that can cause the death of a previously healthy individual within hours. Paradoxically, the causative agent, Neisseria meningitidis, is a common inhabitant of the human nasopharynx, and as such, may be considered a normal, commensal organism. Only in a small proportion of colonized people do the bacteria invade the bloodstream, from where they can cross the blood-brain barrier to cause meningitis. Furthermore, most meningococcal disease is caused by bacteria belonging to only a few of the phylogenetic groups among the large number that constitute the population structure of this genetically variable organism. However, the genetic basis for the differences in pathogenic potential remains elusive. By performing whole genome comparisons of a large collection of meningococcal isolates of defined pathogenic potential we brought to light a meningococcal prophage present in disease-causing bacteria. The phage, of the filamentous family, excises from the chromosome and is secreted from the bacteria via the type IV pilin secretin. Therefore, this element, by spreading among the population, may promote the development of new epidemic clones of N. meningitidis that are capable of breaking the normal commensal relationship with humans and causing invasive disease.

Published 21 June 2005 in J Exp Med, 201(12): 1905-13.
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