Co-existence of physiologically similar sulfate-reducing bacteria in a full-scale sulfidogenic bioreactor fed with a single organic electron donor

A combination of culture-dependent and independent methods was used to study the co-existence of different sulfate-reducing bacteria (SRB) in an upflow anaerobic sludge bed reactor treating sulfate-rich wastewater. The wastewater was fed with ethanol as an external electron donor. Twenty six strains of SRB were randomly picked and isolated from the highest serial dilution that showed growth (i.e. 108). Repetitive enterobacterial palindromic polymerase chain reaction and whole cell protein profiling revealed a low genetic diversity, with only two genotypes among the 26 strains obtained in the pure culture. The low genetic diversity suggests the absence of micro-niches within the reactor, which might be due to a low spatial and temporal micro-heterogeneity. The total 16S rDNA sequencing of two representative strains L3 and L7 indicated a close relatedness to the genus Desulfovibrio. The two strains differed in as many as five physiological traits, which might allow them to occupy distinct niches and thus co-exist within the same habitat. Whole cell hybridisation with fluorescently labeled oligonucleotide probes was performed to characterise the SRB community in the reactor. The isolated strains Desulfovibrio L3 and Desulfovibrio L7 were the most dominant SRB, representing 30–35% and 25–35%, respectively, of the total SRB community. Desulfobulbus-like bacteria contributed for 20–25%, and the Desulfobacca acetoxidans-specific probe targeted approximately 15–20% of the total SRB. The whole cell hybridisation results thus revealed a consortium of four different species of SRB that can be enriched and maintained on a single energy source in a full-scale sulfidogenic reactor

Minimal and mild paediatric brain injury: A 3-year cohort of consecutive presentations

OBJECTIVE: To determine the number of children with minimal and mild traumatic brain injury (TBI) and their demographic factors, causes, associated signs/symptoms and management. METHODS: A cross-sectional analysis of consecutive presentations to a tertiary paediatric centre. RESULTS: There were 2043 presentations of minimal and mild TBI over 3 years (minimal TBI = 79.7% [n = 1628]; mild TBI = 20.3% [n = 415]). Mean age was 5.12 years (SD = 5.14) with children ≤3 years comprising 53.2% (n = 1086). There was a bimodal distribution in mild TBI with peaks at 0-2 and 13-15 years. The male-to-female ratio was 1.6:1. Only 34.6% of GCS scores were documented. Falls caused most injury. Overall, 6.3% (n = 129) required hospital admission and 29.1% (n = 594) were reviewed clinically. CONCLUSION: Minimal and mild TBI is common, representing a significant burden on individuals, families and healthcare providers. High rates of follow-up impact on the healthcare system and warrant further investigation.Remo Nunzio Russo, James Rice, Phei Ming Chern, Jeremy Rafto