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The purpose of this work was to determine the extent of microbial metabolic potential for polychlorinated biphenyls (PCBs) in soils that have had no previous exposure to this class of xenobiotic pollutants. Soil and sediment samples of distinct characteristics from six sites in Germany were used to inoculate PCB oil (Aroclor 1242) microdroplets. All samples yielded multispecies biofilms, as revealed by single-strand conformation polymorphism (SSCP) analyses of polymerase chain reaction (PCR) analysis of 16S rRNA genes, and sequence analysis of the main amplicons. Microbes representing 20 different operational taxonomic units (OTUs) were identified in the biofilms, but only a few were common to all biofilms, namely those closely related to Aquabacterium sp., Caulobacter sp., Imtechium assamiensis, Nevskia ramosa, Parvibaculum lavamentivorans and Burkholderia sp. The PCB biofilm communities were always distinct from control biofilms developing from the same samples in the absence of PCB. All PCB droplet-grown biofilms degraded multiple PCB congeners but differed in the congener spectra they degraded. These findings reveal that microbial potential to degrade PCBs is widespread in soils that have not been subjected to PCB contamination, and that this potential is characteristic of consortia of very diverse phylogenetic composition. [ABSTRACT FROM AUTHOR]

The presumptive metabolically active members of a bacterial community in a moorland soil in Germany, highly polluted with polychlorinated biphenyls (PCBs), were identified by sequencing of cloned reverse transcription–polymerase chain reaction (RT–PCR) amplification products of 16S rRNA generated from total RNA extracts. Analysis of the 16S rRNA clone library revealed a considerable diversity of metabolically active bacteria in the soil, despite the acidic pH and high concentrations of PCBs. Cloned sequence types clustered within the Proteobacteria (34% alpha-, 33% beta- and 7% gamma-subclasses), the Holophaga –Acidobacterium phylum (14%), the Actinobacteria (6.5%) and the Planctomycetales (2%). Three cloned sequence types were not affiliated to any described phylogenetic group. An unusual feature of this soil was the abundance of sequence types within the beta-subclass of the Proteobacteria , most of which were similar to the 16S rRNA gene sequences of species from only two genera, Burkholderia and Variovorax . Three other numerous 16S rRNA sequence types were similar to the sequences of Sphingomonas species, members of the Rhodopila globiformis group and Acidobacterium capsulatum . Some of the sequence types retrieved were similar to the 16S rRNA sequences of bacterial isolates able to degrade a variety of organic pollutants, including PCBs. As the PCB contamination is the major source of measurable carbon in this soil, some of the 16S rRNA sequence types detected and presumed to represent the metabolically active members of the community indicate the organisms likely to be involved, directly or indirectly, in the utilization of the PCBs as carbon and energy sources. [ABSTRACT FROM AUTHOR]

Aims: Recent work has been focused on causes of and risk factors for rhythm management device infections. The aim of this study was to elucidate whether patients may be asymptomatic carriers of bacteria on their rhythm management device, possibly allowing later manifestation of infection., Methods and Results: A total of 108 devices were changed for battery depletion between April 2005 and February 2006 in asymptomatic patients who were examined for evidence of bacterial DNA on the device and in the surrounding tissue using single strand conformation polymorphism analysis (SSCP). Follow-up was for 23.4 months. In 47.2% of the patients, bacterial DNA was demonstrated on the device, which had been in place for 64.1 months. The sequences identified bacterial strains that are untypical for clinical device infections. Staphylococci were demonstrated in only 3.7% of the patients and they became symptomatic within the observation interval; all others remained asymptomatic. The known risk factors for device infections did not correlate with the demonstration of bacterial DNA in this population. Common cohabitation was identified among the strains found., Conclusion: A large proportion of patients carry bacteria on their pacemaker or implantable cardioverter defibrillator asymptomatically. The strains found differ from those commonly seen in clinically evident device infections. Common risk factors for device infection did not correlate with the presence of DNA.