Solobacterium

Abstract: Solobacterium moorei, the only species in the genus Solobacterium, is a Gram-positive, non-spore-forming, strict anaerobic, short to long bacillus. It has rarely been documented to cause blood stream infections. Here we report the first case of bacteremia caused by S.moorei in China. A 61-year-old male presented to Peking Union Medical College Hospital (Beijing) with thrombotic thrombocytopenic purpura (TTP) and several other underlying diseases. He also had persistent coma accompanied by intermittent convulsions, halitosis, and intermittent fever. Blood cultures taken when the patient had a high fever were positive, with the anaerobic bottle yielding an organism identified as S.moorei by 16S rRNA gene sequencing, whilst the aerobic bottle grew Streptococcus mitis. After replacement of venous pipeline, and empirical use of vancomycin and meropenem, the patient’s body temperature and white blood cell count returned to normal. Unfortunately, the patient died of severe TTP. This is the first case report of S. moorei isolation from blood stream in China. 16S rRNA gene sequencing is the only method that can identify S. moorei. Blood cultures must be taken before administration of antibiotics, and anaerobic culture should be considered for such rare pathogens in patients with oral diseases and immune deficiency.

Abstract: Solobacterium moorei is an anaerobic Gram-positive bacillus present within the oral and the intestinal microbiota that has rarely been described in human infections. Besides its role in halitosis and oral infections, S. moorei is considered to be an opportunistic pathogen causing mainly bloodstream and surgical wound infections. We performed a retrospective study of 27 cases of infections involving S. moorei in two French university hospitals between 2006 and 2021 with the aim of increasing our knowledge of this unrecognized opportunistic pathogen. We also reviewed all the data available in the literature and in genetic and metagenomic sequence databases. In addition to previously reported infections, S. moorei had been isolated from various sites and involved in intra-abdominal, osteoarticular, and cerebral infections more rarely or not previously reported. Although mostly involved in polymicrobial infections, in seven cases, it was the only pathogen recovered. Not included in all mass spectrometry databases, its identification can require 16S rRNA gene sequencing. High susceptibility to antibiotics (apart from rifampicin, moxifloxacin, and clindamycin; 91.3%, 11.8%, and 4.3% of resistant strains, respectively) has been noted. Our global search strategy revealed S. moorei to be human-associated, widely distributed in the human microbiota, including the vaginal and skin microbiota, which may be other sources for infection in addition to the oral and gut microbiota.

Abstract: Objective To analyze the microbial profiles of the tongue dorsa in halitosis patients.Methods The samples from the dorsal tongue surface were taken from 7 halitosis patients and 4 control subjects without halitosis.16S rRNA genes of bacteria from the samples were amplified by PCR with universally conserved bacterial primers,cloned into Escherichia coli and sequenced.Phylogenetic trees were constructed by software CLUSTALⅩ 1.83 and TREEVIEW.Results A total of 212 isolates and phylotypes were identified from the 11 subjects,42 species (including 9 uncultured species) were found in subjects with halitosis,while 23 species (including 7 uncultured species) were found in control subjects.Streptococcus sp was the most popular species in both groups.The detection rate of TM7 phylum sp was the highest in subjects with halitosis,followed by Veillonella dispar and Solobacterium moorei.Conclusion The biodiversity of the tongue dorsa of subjects with halitosis was higher than that of subjects without halitosis.TM7 phylum sp,Veillonella dispar,Solobacterium moorei may be related to halitosis.