Bacteriology of Spontaneous Intra-Abdominal Abscess in Patients with Crohn Disease in China: Risk of Extended-Spectrum Beta-Lactamase-Producing Bacteria

Background: Crohn disease (CD) has its own features and the etiology is believed to be related to the gastrointestinal flora, which are the cause of most intra-abdominal infections. However, few experiences have been reported regarding the specific bacteriology of spontaneous intra-abdominal abscess (IAA) in CD patients and related risk factors. In the present study, we aim to investigate the bacteriology of IAA in CD and the associated risk factors. Methods: Retrospective study on 97 CD patients suffering from IAA was performed from January 2007 to December 2012. Microbiologic information of pus cultures was pooled, and logistic regression was applied to examine the possible factors affecting the incidence of common organisms and the bacteria producing extended-spectrum beta-lactamase (ESBL). Results: Of the 97 patients recruited, 151 aerobic bacteria were cultured from the pus of IAA. The leading bacteria were Escherichia coli (57.7%), Klebsiella pneumoniae (19.6%) and Enterococcus faecium (18.6%). Extended-spectrum beta-lactamase-producing bacteria were more commonly found among CD patients receiving immunosuppressant. Conclusions: Broad-spectrum antibiotics are recommended for treating IAA in CD. Empirical antibiotic coverage against ESBL-producing bacteria in patients receiving immunosuppressive therapy is advocated. Considering the predominance of Enterococcus faecium, it may be advisable to use more effective antibiotics when gram-positive cocci are suspected.