Human Listerial Meningitis: Reported from Karachi, Pakistan

One hundred and twenty clinical samples comprising of cerebrospinal fluid (CSF) and blood of 60 patients showing symptoms of meningitis were screened for the presence of L. monocytogenes. One out of 60 CSF samples was found to harbor L. monocytogenes, incidence being 1.66%. This sample was procured from an 18 year old girl. Symptoms were indicative of meningitis or meningoencephalitis. There was no history of immunosuppressive therapy or any other underlying disease. The pathogen seems to have been transmitted through food. Organism was confirmed as L. monocytogenes by cultural, biochemical and serological tests recommended for identification of Listeria. Antibiotic susceptibility test showed that the organism was sensitive to penicillin, ampicillin, gentamicin and tetracycline. Ampicillin and gentamicin demonstrated a synergistic effect. The patient did not suffer from bacterimia as L. monocytogenes was not found in her blood. Blood samples of other patients were also negative in this respect. A comprehensive review of literature indicates that this is the first report of listerial meningitis from this region. The need of through screening is emphasized.