Detection of methanogens in peri-appendicular abscesses: Report of four cases.

The aetiology of appendicular abscess is predominantly microbial with aerobic and anaerobic bacteria from gut flora. In this study, by using specific laboratory tools, we co-detected Methanobrevibacter oralis and Methanobrevibacter smithii among a mixture of enterobacteria including Escherichia coli, Enterococcus faecium and Enterococcus avium in four unrelated cases of postoperative appendiceal abscesses. These unprecedented observations raise a question on the role of methanogens in peri-appendicular abscesses, supporting antibiotics as an alternative therapeutic option for appendicitis, including antibiotics active against methanogens such as metronidazole or fusidic acid.