Phylogenetic diversity and temporal variation in the Spirochaeta populations from two Mediterranean microbial mats

Spirochetes represent one of the bacterial groups often observed in hydrogen- sulfide-rich layers from coastal microbial mats. However, relatively few spirochetes from these microbial mats have been described and characterized. We have used 16S rDNA phylogenetic analysis to investigate the spirochetal diversity of microbial mats from two different geographic locations in the western Mediterranean (Ebro Delta, Spain, and Camargue, France). Samples from each delta was monitored in the spring and winter over 1 to 2 year’s duration. In the sequence analysis of 332 clones derived from samples of both deltas, 42 novel phylotypes of not-yet-cultivated spirochetes belonging to the genus Spirochaeta were detected. None of the phylotypes were identified as known culturable species of Spirochaeta or previously identified phylotyepes cloned from other hypersaline microbial mat such as Guerrero Negro. Eight of the phylotypes were common to Ebro and Camargue mats, two of them, IF058 and LL066 are present both in spring and winter. Some phylotypes appeared to show seasonal variation, i.e. they were found only in the spring, but not in the winter. On the other hand, Ebro and Camargue phylotypes compared with phylotypes from Guerrero Negro grouped according to the vertical gradient of oxygen and sulfide in the mat. Some phylotypes, such as LH073, IE028, LH042 or LG013 are harbored in low H2S or H2S-O2 interface zone. In contrast, major phylotypes were detected presumably in deeper layers and they are likely to be strict anaerobes and high tolerance to H2S. The presence of spirochetes in different located microbial mats suggests that constitutes a very diverse and stable population involved in a well-integrated “symbiosis” (i.e., permanent physiological cooperation) with other guild-populations in the mats to maintain a coordinated functional and stable community

The Strengths and Difficulties Questionnaire in the Nordic countries

Background: The Strengths and Difficulties Questionnaire (SDQ) has been translated into the different Nordic languages between 1996 and 2003. During the past few years, SDQs have been completed for nearly 100,000 children and adolescents in population-based studies as well as in clinical samples. The largest studies have been performed in Norway and Denmark, and in these countries the diagnostic interview DAWBA has also been used in conjunction with the SDQ. Aims: In addition to a brief overview of past and ongoing SDQ work in Sweden, Finland, Norway, Denmark, and Iceland, we present scale means and standard deviations from selected community studies with comparable age groups, including parental reports for 7, 9 and 11 year-old children and self-reports of 13 and 15 year-olds. Conclusions: The descriptive statistics suggest that the distributions of SDQ scores are very similar across the Nordic countries. Further collaborative efforts in establishing norms and evaluating the validity of the SDQ as a screening instrument are encouraged