Optimization of DNA extraction from dental remains.

Efficient DNA extraction procedures is a critical step involved in the process of successful DNA analysis of such samples. Various protocols have been devised for the genomic DNA extraction from human tissues and forensic stains, such as dental tissue that is the skeletal part that better preserves DNA over time. However DNA recovery is low and protocols require labor-intensive and time-consuming step prior to isolating genetic material. Herein, we describe an extremely fast procedure of DNA extraction from teeth compared to classical method. Sixteen teeth of 100-year-old human remains were divided into two groups of 8 teeth and we compared DNA yield, in term of quantity and quality, starting from two different sample preparation steps. Specifically, teeth of group 1 were treated with a classic technique based on several steps of pulverization and decalcification, while teeth of group 2 were processed following a new procedure to withdraw dental pulp. In the next phase, the samples of both group underwent the same procedure of extraction, quantification and DNA profile analysis. Our findings provide an alternative protocol to obtain a higher amount of good quality DNA in a fast time procedure, helpful for forensic and anthropological studies.

Biofilm's Role in Chronic Cholesteatomatous Otitis Media: A Pilot Study.

Cholesteatoma is a destructive lesion involving the temporal bone, which may induce severe complications due to its expansion and erosion of adjacent structures. Bacterial biofilm plays a crucial role in the pathogenesis of many otolaryngologic inflammatory/infectious chronic diseases. In this pilot study, we investigated, by means of cultural examination and with scanning electron microscope, the presence of bacterial biofilm in a series of samples from the epitympanic and mastoid region in patients affected by cholesteatoma and from the promontory region in patients with healthy mucosa who were undergoing to stapes surgery. The preliminary data support the association between biofilm and cholesteatoma (81.3% of the cases) and allow us to hypothesize that keratinized matrix of cholesteatoma may represent the ideal substrate for biofilm colonization and survival; this finding is consistent with the clinical course of aural cholesteatoma, characterized by recurrent exacerbations and recalcitrant course.

Damage to ciliated epithelium in chronic rhinosinusitis: what is the role of bacterial biofilms?

OBJECTIVES: We assess the association between the presence of biofilms and cilial damage in patients with chronic rhinosinusitis (CRS), describe the microorganisms associated with samples that exhibited cilial loss and biofilms, and demonstrate the absence of ciliary injury and biofilms in similarly prepared "normal" controls. METHODS: We examined samples of ethmoid mucosa obtained from 24 patients who underwent functional endoscopic sinus surgery for CRS. Samples from a control group (20 healthy subjects) were also examined. The specimens were divided into 2 fragments; the first was processed for bacterial cultures, and the second was subjected to scanning electron microscopy. Statistical analysis was performed. RESULTS: All CRS samples had positive bacterial cultures. The scanning electron microscopy analysis showed bacterial biofilms in 10 of the 24 specimens. A marked destruction of the epithelium was observed in samples positive for biofilms (p < 0.001), and the presence of Haemophilus influenzae was associated with ciliary abnormalities (partial damage in 55.6% and absence of cilia in 50%; p = 0.041). CONCLUSIONS: The high percentage of biofilms in our specimens confirms the association between biofilms and CRS. Our data support the hypothesis that biofilm formation represents the latter phase of an inflammatory process that leads to complete epithelial destruction.