Hypersaline Lake Urmia: a potential hotspot for microbial genomic variation

Lake Urmia located in Iran is a hypersaline environment with a salinity of about 27% (w/v). Metagenomic analyses of water samples collected from six locations in the lake exhibited a microbial community dominated by representatives of the family Haloferacaceae (69.8%), mainly those affiliated to only two genera, Haloquadratum (59.3%) and Halonotius (9.1%). Similar to other hypersaline lakes, the bacterial community was dominated by Salinibacter ruber (23.3%). Genomic variation analysis by inspecting single nucleotide variations (SNVs) and insertions/deletions (INDELs) exhibited a high level of SNVs and insertions, most likely through transformation for abundant taxa in the Lake Urmia community. We suggest that the extreme conditions of Lake Urmia and specifically its high ionic concentrations could potentially increase the SNVs and insertions, which can consequently hamper the assembly and genome reconstruction from metagenomic reads of Lake Urmia

Genomic fingerprints of Escherichia coli strains isolated from surface water in Alborz province, Iran

Abstract Background Consistent use of suitable diagnostic methods is essential to evaluate the genomic diversity of E. coli strains. Advance of efficient methods to discriminate the causes of E. coli in aquatic environments is important. This study aimed to describe the strain diversity of an E. coli population retrieved from surface water. Methods One hundred water samples were drawn within a period of 1 year, from May 2012 to May 2013, and E. coli bacteria have been isolated from water samples. The genomic diversity analysis of 100 isolates of E. coli (one isolate per sample) has been carried out with the use of the ERIC-PCR fingerprinting method. Results Overall, our data indicated that complex fingerprint patterns have been obtained for totally of the isolates. Highest number of strains were in E4 (20 strains with more than 20% similarity) and lowest number of strains were in E3 (5 strains) group. In addition, there was no similarity in E1 (9 strains), E8 (10 strains) and E9 (7 strains) clusters. Conclusion Therefore, the occurrence of potential pathogenic E. coli and diversity of E. coli strains in surface water in Alborz province, Iran could pose a possible risk to animal health and human if not disinfected well