Community-acquired meningitis in adults due to E. coli is a rare entity. The main risk factors are alcoholism, cirrhosis, neoplasic diseases, diabetes mellitus, and treatment with immunosuppressive agents [3–7]. Others cases occur frequently in neurosurgery and are usually associated with multi-drug resistant strains [8–11]. In our observation, the patient had no risk factors except a chronic alcoholism and perhaps his dog as animal pet.
In Europe, there is an increasing in 3rd generation cephalosporin resistant E. coli isolates in both hospital setting and the community. CTX-M ESBL is the most common genetic support of resistance in these strains . In our case report, we suspected this mechanism. The spread of E. coli producing ESBL is now well- identified .
Blood stream infections due to E. coli in adults are often related to underlying urinary or bilary tract or other intra-abdominal infections. Vascular infections and meningitis due to E. coli are exceedingly rare and few cases isolated have been reported [14–16]. Diabetes mellitus, previous fluoroquinolone use, recurrent urinary tract infection, previous hospital admission and older age in male patients have been identified as risk factors for infection of ESBL-producing E. coli . Recently, Ewers and al. suggested the possibility of inter-species transmission of multiresistant strains of E. coli from human to animal and vice versa .
The current guidelines for the management of gram negative bacilli (GNB) related meningitis are well codified and recommend the use of a 3rd generation cephalosporins ± gentamicin. Alternative therapies are Cefepime, meropenem, aztreonam, fluoroquinolone, and trimethoprim-sulfamethoxazole [1, 2]. In our case report, meropenem (in association with ciprofloxacin) was used because of the lower risk of seizures compared to imipenem [19, 20]. Mortality associated with GNB related meningitis varied from 25 to 100% [7, 21]. Lu et al. identified several risk factors for mortality associated to GNB related meningitis: inappropriate initial treatment, septic shock, initial level of consciousness, hyperosmolar hyperglycemic coma, disseminated intravascular coagulation, high CSF lactate levels and leucocytosis. In the multiple logistic regression analysis, only appropriate antimicrobial therapy and septic shock were strongly associated with mortality even after adjusting for other potentially confounding factors . Inappropriate treatment and septic shock were initially present in our patient. The presence of a concomitant aortic mycotic aneurysm was an additional factor of mortality.
Only two cases of mycotic aneurysm in patient presenting initially bacterial meningitis have been reported [22, 23]. The first case is a 65-year old woman with ruptured mycotic aneurysm in a patient with pneumococcal meningitis, who died on week later. The second case is a 57 year-old man with a history of CFS fistula and multiple neurosurgical treatment, who developed meningitis complicated with endocarditis and thoracic aortic infection. No bacteria were identified in this second case. The patient was successfully treated with endovascular prosthesis. In the present case report, multiple mycotic aneurysms were suspected because of the sustained bacteremia, the atypical and multiple foci of vascular infection, the normality of the first abdominal CT scan and the rapid evolution of aneurysm. the aortic involvement may be the result of infection of the aortic wall.