[A case of post-operative cerebral abscess caused by multidrug-resistant Acinetobacter baumannii-possibly originating abroad, and poorly susceptible to colistin].

We report a case of post-neurosurgical meningitis, subdural empyema, and cerebral abscess caused by multidrug-resistant Acinetobacter baumannii (MRAB) poorly susceptible to colistin. A 49-year-old man was transferred to our hospital after surgical treatment for putaminal hemorrhage in a foreign country hospital. Several examinations revealed surgical site infection (SSI). From cerebro-spinal fluid examination via ventricular drainage, MRAB was recovered. The minimum inhibitory concentration (MIC) of colistin was 2 µg/mL. Intravenous administration of colistin with ceftazidime and rifampicin was started, with intrathecal colistin administration, based on the results of a Break-point Checkerboard examination, and resulted in effective infection control. Nosocomial infection by MRAB has become an emergent problem in many countries. In Japan, several outbreak accidents caused by MRAB have been reported so far. In this case, genetic analysis revealed that the pathogen had originated from a foreign country, and the prevalence of colistin-resistant pathogens has also increased in these countries. Besides adequate isolation precautions, strategies for post-neurosurgical SSI management and establishment of effective treatments are necessary against neurosurgical SSIs caused by colistin-resistant MRAB.

A case of meningitis due to Neisseria subflava after ventriculostomy.

Surgical site infection (SSI) is an emerging problem in all fields of surgery, as well as in neurosurgery, with numerous strategies against SSI initiated in many countries. In this report, we describe a case of SSI caused by Neisseria subflava a month after ventriculostomy placement for acute hydrocephalus. A 53-year old man was referred to our hospital, and was diagnosed with a thalamic hemorrhage with ventricular rupture. Bilateral ventriculostomies were performed on the day of presentation. After intensive care for the acute stage, an SSI at the left ventriculostomy site was recognized on the 39th hospital day. The installed reservoir and ventricular tube was removed on the 40th hospital day. The CSF cell count was 2064/3, and N. subflava was recovered from the CSF culture. N. subflava is a common inhabitant found in the human upper respiratory tract, and is reported to be a rare cause of meningitis. There is one case report of meningitis caused by N. subflava transmitted during myelography from medical staff who did not wear facemasks during the procedure. Meningitis caused by N. subflava is rare, and transmission via a medical procedure is extremely rare. Although reported to be only rarely pathogenic, we must recognize that N. subflava can indeed be pathogenic, and can in rare cases be the cause of postoperative meningitis.