Category Archives: Uncategorized

PlosOne

We spend the majority of our lives indoors where we are constantly exposed to bacteria residing on surfaces. However, the diversity of these surface-associated communities is largely unknown. We explored the biogeographical patterns exhibited by bacteria across ten surfaces within each of twelve public restrooms. Using high-throughput barcoded pyrosequencing of the 16 S rRNA gene, we identified 19 bacterial phyla across all surfaces. Most sequences belonged to four phyla: Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria. The communities clustered into three general categories: those found on surfaces associated with toilets, those on the restroom floor, and those found on surfaces routinely touched with hands. On toilet surfaces, gut-associated taxa were more prevalent, suggesting fecal contamination of these surfaces. Floor surfaces were the most diverse of all communities and contained several taxa commonly found in soils. Skin-associated bacteria, especially the Propionibacteriaceae, dominated surfaces routinely touched with our hands. Certain taxa were more common in female than in male restrooms as vagina-associated Lactobacillaceae were widely distributed in female restrooms, likely from urine contamination. Use of the SourceTracker algorithm confirmed many of our taxonomic observations as human skin was the primary source of bacteria on restroom surfaces. Overall, these results demonstrate that restroom surfaces host relatively diverse microbial communities dominated by human-associated bacteria with clear linkages between communities on or in different body sites and those communities found on restroom surfaces. More generally, this work is relevant to the public health field as we show that human-associated microbes are commonly found on restroom surfaces suggesting that bacterial pathogens could readily be transmitted between individuals by the touching of surfaces. Furthermore, we demonstrate that we can use high-throughput analyses of bacterial communities to determine sources of bacteria on indoor surfaces, an approach which could be used to track pathogen transmission and test the efficacy of hygiene practices.

Wiley Online Library 

The study aimed to determine genetic diversity of a collection of New Zealand Cronobacter isolates collected from different sources and their ability to form a biofilm on different materials under different conditions. Isolates were screened for the presence of biofilm associated genes. Furthermore, suppression subtractive hybridization (SSH) was used to identify unique genes, present in a C. sakazakii strain (isolate ES191) which forms a stronger biofilm than the reference strain C. sakazakii BAA894. Results indicated that New Zealand Cronobacter spp. strains were genetically diverse. Biofilm formation was both temperature and nutrient dependent and varied widely within and between clinical, dairy, and environmental isolates. Moreover, C. akazakii adhered more to polyvinyl chloride followed by silicone, polyurethane and stainless steel and all the isolates harbored biofilm related genes. Of the 72 PCR products sequenced from the SSH library, 16 unique gene sequences were identified, of which nine were expressed only in ES191 and were found to be involved in hypothetical protein, energy production, and virulence. This study suggests the choice of enteral neonatal feeding tube material could dramatically influence the attachment, growth, and biofilm formation of C. sakazakii.

Devon on Line

The number of potentially-lethal blood infections caused by E. Coli in Devon has increased more than the national average in one year.

Across Devon there were 918 cases of E. Coli infecting the blood stream – called bacteraemia – in 2016/17.

That was a 10% increase on the 836 cases recorded the year before.

Bacteraemia is a serious infection that occurs when bacteria get into the bloodstream. It may lead to sepsis and can be fatal.

E. Coli is a blanket name given to several species of bacteria – in the same way that humans all belong to the same species but are not identical to each other.