Statistical significance of branching was selleck chemical verified by bootstrapping. The scale bar represents a 5% estimated sequence divergence, and reference sequences were obtained from the GenBank Database. Table 1 Distribution and abundance of 16S rRNA gene sequences in the clone library Organism No. of clones Unclassified Firmicutes 1 Clostridiales   Clostridium 114 Dorea 1 Ruminococcus 2 Subdoligranulum 1    Unclassified Clostridiaceae 34 Unclassified Clostridiales 8 Total 161 Table 2 Polar bear 16S rRNA gene clones

representing 17 valid phylotypes Phylotype Genbank acc. no. Size (bp) No. of clones Nearest valid relative Sequence similarity (%) PBF_d7 FJ375870 1439 67 Clostridium perfringens (CP000246) 99.9 PBF_b25 FJ375795 1466 35 Clostridium sordellii (DQ978216) 99.5 PBF_c44 FJ375859 1438 18 Clostridium sardiniense (AB161368) 98.5 PBM_b9 FJ375922 1427 8 Clostridium hiranonis (AB023971) 98.2 PBF_b17 FJ375788 1402 7 Clostridium colicanis (AJ420008) 99.8 PBM_b1 FJ375916 1433 5 Clostridium glycolicum (X76750) 98.3 PBM_a8 FJ375915 1430 5 Clostridium bartlettii (AY438672) 96.6 PBF_c29 FJ375847 1444 3 Clostridium paraputrificum (AY442815) 99.7 PBF_b21 FJ375792 1452

2 Clostridium perfringens (CP000246) 99.5 PBF_b32 FJ375802 1372 2 Ruminococcus hansenii (M59114) 95.3 Stem Cells antagonist PBF_b47 FJ375816 1464 2 Clostridium sordellii (DQ978216) 98.3 PBM_b18 FJ375928 1459 2 Ruminococcus gnavus (X94967) 99.4 PBM_b10 FJ375923 1460 1 Clostridium sordellii (DQ978215) 99.5 PBF_d3 FJ375866 1436 1 Clostridium perfringens (Y12669) 99.5 PBF_d10 FJ375873 1453 1 Clostridium disporicum (Y18176) 98.3 PBF_b35 FJ375805 1488 1 Firmicutes bacterium (AF157051) 95.1 PBM_a2 FJ375911 1431 1 Unclassified bacterium (DQ057466) 96.6 Total   161     Aerobic heterotrophic cell counts and β-lactamase activity The Astemizole aerobic heterotrophic cell counts ranged from 5.0 × 104 to 1.6 × 106 cfu/ml for the rectum swabs, and from 4.0 × 103 to 1.0 × 105 cfu/g for the faeces samples (Table 3 and 4). The coliform counts for the faeces samples ranged from 3.2 × 103 to 8.0 × 104 cfu/g. There was no growth of ampicillin

resistant bacteria in the faeces samples. For the rectal swabs, the proportion of ampr bacteria ranged between 3% and 44% (Table 3). A total of 144 randomly selected ampr isolates cultivated from rectal swab samples were tested for β-lactamase activity by the nitrocefin test and all isolates showed β-lactamase activity. Table 3 Aerobic heterotrophic, coliform, and ampicillin resistant cells counts (cfu/ml) in rectum swabs from polar bears in Svalbard Polar bear no. Aerobic heterotrophic cellsa Ampr aerobic heterotrophic cellsb % c 1 5.0 × 104 (± 5.0 × 103) 1.6 × 103 (± 6.3 × 102) 3 2 NC 1.0 × 104 (± 1.6 × 103) – 3 NC NC – 5 1.6 × 106(± 2.0 × 105) 8.0 × 105 (± 1.0 × 105) 44 aMean values are based on nine replicates. bMean values are based on three replicates.