First report of Neisseria meningitidis intermediately resistant to penicillin in Croatia

Neisseria meningitidis is one of the leading causes of bacterial meningitis and sepsis in Croatia. Meningococcal strains with decreased susceptibility to penicillin (MIC > 0.12 mg/ml) have been reported worldwide since 1985. Here we report the first identification of an isolate intermediately resistant to penicillin in Croatia. An 8-month-old male child presented to the Emergency Department at University Hospital for Infectious Diseases, Zagreb, Croatia, with a 2-day history of fever (>39 degree C). The child was somnolent, with characteristic meningeal signs and petechia on its scrotum and entire extremities. The white blood cell count was 5,800/mm super(3), with 51 segmented neutrophils and 32 lymphocytes. The cerebrospinal fluid (CSF) contained 92,416 cells/mm super(3), the protein concentration was 2,040 mg/liter, and the glucose concentration was 0.3 mmol/liter. Gram-negative diplococci were visible on a Gram-stained smear, and latex agglutination performed on the CSF was positive for N. meningitidis serogroup B (Slidex meningite-Kit 5; bioMerieux, Marcy-l'Etoile, France). Ceftriaxone therapy was instituted, and household contacts were treated with rifampin.