Genetic diversity of Escherichia coli in gut microbiota of patients with Crohn's disease discovered using metagenomic and genomic analyses.

BACKGROUND: Crohn's disease is associated with gut dysbiosis. Independent studies have shown an increase in the abundance of certain bacterial species, particularly Escherichia coli with the adherent-invasive pathotype, in the gut. The role of these species in this disease needs to be elucidated. METHODS: We performed a metagenomic study investigating the gut microbiota of patients with Crohn's disease. A metagenomic reconstruction of the consensus genome content of the species was used to assess the genetic variability. RESULTS: The abnormal shifts in the microbial community structures in Crohn's disease were heterogeneous among the patients. The metagenomic data suggested the existence of multiple E. coli strains within individual patients. We discovered that the genetic diversity of the species was high and that only a few samples manifested similarity to the adherent-invasive varieties. The other species demonstrated genetic diversity comparable to that observed in the healthy subjects. Our results were supported by a comparison of the sequenced genomes of isolates from the same microbiota samples and a meta-analysis of published gut metagenomes. CONCLUSIONS: The genomic diversity of Crohn's disease-associated E. coli within and among the patients paves the way towards an understanding of the microbial mechanisms underlying the onset and progression of the Crohn's disease and the development of new strategies for the prevention and treatment of this disease.

Transoral Removal of Ventrally Located Meningiomas of the Craniovertebral Junction.

BACKGROUND: Surgical treatment of ventral pathologic lesions of the craniovertebral junction and upper cervical spine is extremely difficult due to limited accessibility, as well as the difficulty of performing surgical manipulations in a deep, narrow wound in conditions of restricted surgical freedom and angle of attack. METHODS: In this article we present 2 clinical cases in which the transoral approach was used to treat ventral meningiomas of the craniovertebral junction. Endoscopic assistance and an original method of anterior atlantooccipital stabilization were used. RESULTS: Subtotal removal in the first case and complete removal of the tumor in the second case were achieved. In the first case, an unsuccessful attempt of anterior stabilization was made. In the second case, there were no indications for instrumentation (anterior or posterior) as local bone autograft fusion between the condyles and lateral masses of C1 was effectively carried out. CONCLUSIONS: Previously, the transoral approach garnered interest only from a historical point of view, but with technical progress it has acquired a "second life." Novel surgical techniques allow for a more radical resection of named tumors, as well as lower morbidity and invasiveness of the surgical procedures, which, in the long term, leads to lower complication rates.