Enzymatic phosphatization of fish scales-a pathway for fish fossilization.

Phosphatized fish fossils occur in various locations worldwide. Although these fossils have been intensively studied over the past decades they remain a matter of ongoing research. The mechanism of the permineralization reaction itself remains still debated in the community. The mineralization in apatite of a whole fish requires a substantial amount of phosphate which is scarce in seawater, so the origin of the excess is unknown. Previous research has shown that alkaline phosphatase, a ubiquitous enzyme, can increase the phosphate content in vitro in a medium to the degree of saturation concerning apatite. We applied this principle to an experimental setup where fish scales were exposed to commercial bovine alkaline phosphatase. We analyzed the samples with SEM and TEM and found that apatite crystals had formed on the remaining soft tissue. A comparison of these newly formed apatite crystals with fish fossils from the Solnhofen and Santana fossil deposits showed striking similarities. Both are made up of almost identically sized and shaped nano-apatites. This suggests a common formation process: the spontaneous precipitation from an oversaturated solution. The excess activity of alkaline phosphatase could explain that effect. Therefore, our findings could provide insight into the formation of well-preserved fossils.

Complicated sea urchin-induced wound infection caused by Vibrioalginolyticus and Staphylococcus lugdunensis in a 14-year-old boy.

INTRODUCTION: Wound infections with Vibrio alginolyticus, a Gram-negative bacterium found in all temperate oceans, are rarely reported. However, a rising incidence of wound infections caused by V. alginolyticus requires better knowledge about this infectious agent. CASE PRESENTATION: We report the case of a 14-year-old boy suffering from a wound infection caused by V. alginolyticus and Staphylococcus lugdunensis after stepping on a sea urchin. Despite wound debridement and antibiotic therapy with cefaclor, the lesion did not heal over several weeks. After identification of the pathogens and antibiotic-susceptibility testing, antibiotic therapy was switched to ciprofloxacin, followed by trimethoprim/sulfamethoxazole. Two months after the accident the wound was re-epithelialized. Follow up after 6 months revealed a painful scar. CONCLUSION: Non-cholera vibrios like V. alginolyticus should be considered as possible causative agents in seawater-contaminated wounds. S. lugdunensis is a relevant pathogen in mixed wound infections. Early microbiological diagnosis and antibiotic-susceptibility testing is crucial to prevent therapeutic failure.

MAKERGAUL: an innovative MAK2-based model and software for real-time PCR quantification.

OBJECTIVES: Gene expression analysis by quantitative PCR is a standard laboratory technique for RNA quantification with high accuracy. In particular real-time PCR techniques using SYBR Green and melting curve analysis allowing verification of specific product amplification have become a well accepted laboratory technique for rapid and high throughput gene expression quantification. However, the software that is applied for quantification is somewhat circuitous and needs actually above average manual operation. DESIGN AND METHODS: We here developed a novel, simple to handle open source software package (i.e., MAKERGAUL) for quantification of gene expression data obtained by real time PCR technology. RESULTS: The developed software was evaluated with an already well characterized real time PCR data set and the performance parameters (i.e., absolute bias, linearity, reproducibility, and resolution) of the algorithm that are the basis of our calculation procedure compared and ranked with those of other implemented and well-established algorithms. It shows good quantification performance with reduced requirements in computing power. CONCLUSIONS: We conclude that MAKERGAUL is a convenient and easy to handle software allowing accurate and fast expression data analysis.