Journal of Clinical and Diagnostic Research. 2011 June, Vol-5(3): 608-609 608 608 INTRODUCTION Listeria monocytogenes is a gram positive intracellular pathogen which is associated with a number of clinical entities like septicaemia, abortions, stillbirth, meningitis and meningoencephalitis. The infections by this psychrotrophic organism are commonly seen in pregnant women, newborns, the elderly, in immunocompromised people and in individuals who are in frequent contact with animals [1]. Neonatal infections which are caused by Listeria spp in Asia are quite under reported [2]. A low index of clinical suspicion and the absence of pathognomic clinical features often contribute to this. We illustrate through a case report of late neonatal sepsis, the importance of the identification of Listeria monocytogenes from CSF and blood and its theraupetic implications. CASE REPORT A 2.74 kg, full term, female baby was delivered by an emergency lower segment caesarean section (LSCS) at our hospital. The Apgar scores were 8 at 1 minute and 9 at 5 minutes. The infant progressed fairly until 14 days, after which she developed fever, showed a poor feeding pattern and presented with abnormal movements. On general examination, the patient showed high grade fever, poor feeding with the regurgitation of milk, a vacant stare and a pulse rate of 140/minute. The central nervous system examination showed hypertonia, exaggerated deep tendon reflexes without clonus and tonic posturing with seizures. The patient showed respiratory distress and so, was immediately admitted to the Neonatal Intensive Care Unit (NICU). The patient’s mother was a 22-year-old primi gravida who had presented at 39 weeks of SADIA KHAN, S. SUJATHA, B.N. HARISH, IRA PRAHARAJ, S.C. PARIJA ABSTRACT Introduction: Listeria monocytogenes is an uncommon cause of bacterial meningitis in neonates. Infections due to this organism in neonates can be categorized as an early onset or a late onset disease. While the early onset neonatal listeriosis is due to an in utero infection, the late onset form primarily occurs due to exposure to the organism during vaginal delivery. Case Presentation: Here, we report a 2 week old female child who presented with late onset meningitis due to Listeria monocytogenes and responded adequately to appropriate antimicrobial therapy. Conclusion: Physicians should always consider Listeria as a possible aetiological agent of meningitis in paediatric patients, regardless of their age or immunological status in a developing country. Cephalosporins which are the most commonly used antimicrobials in bacterial meningitis,are unlikely to elicit a favourable response in such cases. Neonatal Meningitis due to Listeria Monocytogenes: A Case Report from Southern India Key Words: Listeria, Neonatal meningitis Case Report Microbiology Section gestation with non progression of labour, as a result of which she was taken up for an emergency caesarean section. The mother did not give any history of fever or any history which was suggestive of any focus of infection. The baby was breast fed till the 14th day of life, when she presented to the paediatric emergency. Laboratory investigations of the infant on admission showed a white blood cell count of 1.2 x 10 9 /l units. The haemoglobin levels and the platelet counts were within normal limits. The cerebrospinal fluid (CSF) showed a glucose concentration of 0.74g/l and a protein concentration of 0.68g/l. The blood glucose level was 0.98g/dl. The gram staining of the CSF showed plenty of polymorphonuclear leucocytes, but no bacteria were visualized. The CSF was inoculated on 5% sheep blood agar, chocolate agar and MaConkey agar. The blood agar was incubated in a CO 2 incubator, while the other media were incubated for 24 hours in ambient air at 37°C. The blood agar showed large colonies with a Narrow zone of β (beta) hemolysis, which was more evident when the colonies were removed. Corresponding growth was seen in chocolate agar, while there was no growth in MaConkey agar. Further tests showed the isolate to be a catalase positive, oxidase negative, gram positive rod, with a tumbling motility at 25°C and non motile at 37°C. Based on the above findings, the organism was presumptively identified as Listeria spp and it was subcultured on Polymyxin Acriflavine Lithium Chloride Ceftazidime Esculin Mannitol Agar (PALCAM) agar, which is a selective medium for Listeria spp. The next day, black colonies which were characteristic of the Listeria spp were seen. Standard biochemical tests showed the organism to be Listeria monocytogenes. Antimicrobial Susceptibility tests which KEY MESSAGE n It is important to differentiate meningitis due to Listeria monocytogenes from other causes as cephalosporins, the most commonly used antibiotics in bacterial meningitis are unlikely to elicit a favourable response in such cases.