Nosocomial Escherichia coli meningitis in adults: Report of four cases and literature review
A 44-year-old Pakistani male patient, admitted to the trauma intensive care unit after having a sustained severe head injury and forearm fracture caused by a car accident. He had immediate loss of consciousness and cranial computed tomography (CT) showed multiple skull fractures involving left frontal bone extending downward to involve the roof of orbit bone, base of the skull and anterior cranial fossa. On the following days the patient improved, he became semiconscious, but cerebrospinal fluid (CSF) leak was noted. On the fifteenth day of admission, patient developed fever with deterioration in his consciousness level. Neurological examination revealed unconscious patient, however, examination for meningeal signs was not possible due to patient's condition. CSF examination showed 6675 leucocytes/μl with 80% neutrophils, a protein level of 230 mg/dl and a glucose level of 34.2 mg/dl. Direct examination of CSF showed Gram-negative rods, and cultures yielded extended spectrum beta lactamase (ESBL) Escherichia coli, sensitive to meropenem, gentamycin and piperacillin-tazobactam. Production of ESBL was determined by disk testing in our clinical microbiology laboratory according to the Clinical and Laboratory Standards Institute performance standards M100-S20. MICs of third generation cephalosporins and of amoxicillin–clavulanate were used as confirmatory criteria of ESBL production detected by the BD Phoenix system. Isolates recorded as possible ESBL producers by the BD Phoenix system were prospectively tested for ESBL production by using combined discs method (BD Sensi-Disc) using ceftazidime (30 μg), cefotaxime (30 μg) with and without clavulanic acid (10 μg). An increase in the inhibition zone diameter ≥5 mm in the presence of clavulanic acid was considered confirmation of ESBL production. Blood cultures were negative. Cranial CT showed parenchymal changes consistent with cerebritis. The patient was treated initially with ceftriaxone (4 g/day), which was shifted to meropenem upon receipt of culture results. The treatment continued for 3 weeks after which the patient improved and discharged from the intensive care unit without any sequela other than his primary illness.