Single-Cell Genomics and the Oral Microbiome.

The human oral cavity is one of the first environments where microbes have been discovered and studied since the dawn of microbiology. Nevertheless, approximately 200 types of bacteria from the oral microbiota have remained uncultured in the laboratory. Some are associated with a healthy oral microbial community, while others are linked to oral diseases, from dental caries to gum disease. Single-cell genomics has enabled inferences on the physiology, virulence, and evolution of such uncultured microorganisms and has further enabled isolation and cultivation of several novel oral bacteria, including the discovery of novel interspecies interactions. This review summarizes some of the more recent advances in this field, which is rapidly moving toward physiologic characterization of single cells and ultimately cultivation of the yet uncultured. A combination of traditional microbiological approaches with genomic-based physiologic predictions and isolation strategies may lead to the oral microbiome being the first complex microbial community to have all its members cultivable in the laboratory. Studying the biology of the individual microbes when in association with other members of the community, in controlled laboratory conditions and in vivo, should lead to a better understanding of oral dysbiosis and its prevention and reversion.

Primary anastomosis without colonic lavage for the obstructed left colon.

INTRODUCTION: Resection, on-table lavage (OTL) and primary anastomosis is the treatment of choice for the obstructed left colon. OTL is time-consuming, requires considerable mobilisation/bowel handling, an enterotomy and potentially exposes the patient to mesenteric vascular injury, faecal contamination and a prolonged ileus. We have assessed outcome following primary resection and anastomosis without prior lavage. PATIENTS AND METHODS: Twenty-four consecutive, obstructed patients underwent splenic flexure mobilisation and high anterior resection (concomitant small bowel resection in 2) with primary side-to-side colorectal anastomosis without either prior lavage or covering stoma. Outcome was audited. RESULTS: Twenty-four patients, 17 female aged 48-92 years (median. 76 years) presented with left-sided obstruction due to carcinoma (Dukes' B [3], C [6], D [1]) or chronic diverticulitis (14). Median operative time was 85 min (range, 40-105 min). Colonic ileus resolved on day 2 (29%) and day 3 (58%). Median hospital stay was 7 days (range, 6-72 days); 92% discharged by day 10. There were no deaths or re-admissions. A return to theatre followed a reactionary haemorrhage in one. This latter patient's anastomosis leaked on day 4 (no faecal contamination) and was converted to an end stoma. Urinary and wound infections were seen in two. Late complications comprised two anastomotic strictures; both responded to balloon dilatation at 5 months. CONCLUSIONS: Resection and primary anastomosis without on-table lavage is an easy, practical, predictable and safe treatment option for left-sided colonic obstruction with minimal complications.