Antimicrobial treatment of Erysipelatoclostridium ramosum invasive infections: a systematic review

ABSTRACT The aim of this systematic review was to determine the causal role of Erysipelatoclostridium ramosum in specific invasive infections in humans, and to assess the clinical outcome of antibiotic therapy used to treat them. Several electronic databases were systematically searched for clinical trials, observational studies or individual cases on patients of any age and gender with a systemic inflammatory response syndrome (SIRS) due to E. ramosum isolated from body fluids or tissues in which it is not normally present. Only reports identifying E. ramosum as the only microorganism isolated from a patient with SIRS were included. This systematic review included 15 studies reporting 19 individual cases in which E. ramosum caused invasive infections in various tissues, mainly in immunocompromised patients. E. ramosum was most often isolated by blood cultures and identified by specific biochemical tests. Severe infections caused by E. ramosum were in most cases effectively treated with antibiotics, except in two patients, one of whom died. More than one isolate of E. ramosum exhibited 100% susceptibility to metronidazole, amoxicillin/clavulanate and piperacillin/tazobactam. On the other hand, individual resistance of this bacterium to penicillin, ciprofloxacin, clindamycin, imipenem and ertapenem was reported. This systematic review confirmed the clinical relevance of E. ramosum as a cause of a number of severe infections mainly in immunocompromised inpatients. Metronidazole and meropenem appear to be the antibiotics of choice that should be used in combination or as monotherapy to treat E. ramosum infections, depending on the type and severity of the infection.