Draft Genome Sequence of Two Sphingopyxis sp. Strains, Dominant Members of the Bacterial Community Associated with a Drinking Water Distribution System Simulator

We report the draft genomes of two Sphingopyxis sp. strains isolated from a chloraminated drinking water distribution system simulator. Both strains are ubiquitous residents and early colonizers of water distribution systems. Genomic annotation identified a class 1 integron (intI1) gene associated with sulfonamide (sul1) and puromycin (pac) antibiotic resistance genes.

Genomic DNA was extracted using the Ultra-Clean DNA microbial isolation kit (MoBio Laboratories, Solana Beach, CA) and sequenced by rapid mode sequencing on the HiSeq 2500 platform (Illumina Inc., San Diego, CA) using a paired-end 125 bp Nextera XT DNA library. Prior to assembly, libraries were (i) cleaned from contaminants (adapters, phiX, artifacts, and human), (ii) error corrected via Tadpole, (iii) normalized to Յ100ϫ, (iv) removed of low (Ͻ6ϫ) coverage reads, and (v) filtered to a minimum length read of 125 nucleotides (nt). Reads were processed using the software package BBMap v35.34 (http://sourceforge.net/projects /bbmap) and de novo assembly with SPAdes v3.5.0 (16). The draft genomes of strains H107 and H115 consist of 57 and 63 contigs for a total of 4,308,137 and 4,493,891 bp with a GϩC content of 64.84 and 64.33%, respectively. Genome assemblies were annotated with Prokka v1.10 (17) available as an application in Illumina BaseSpace Labs. The genome sequence of strain H107 contains 4,244 genes, 4,191 coding sequences (CDSs), 3 rRNAs, and 50 tRNAs, and strain H115 contains 4,327 genes, 4,277 CDSs, 3 rRNAs, and 47 tRNAs.
Genomic annotation of the environmental H115 strain confirmed the presence of the class 1 integrase (intl1) gene associated with the dihydropteroate synthase (sul1) gene, encoding resistance to sulfonamide (23). In addition, sul1 gene was found linked to the puromycin-N-acetyltransferase (pac) gene. The pac gene encodes resistance to puromycin, an aminonucleoside antibiotic whose mode of action is distinct from the dihydropteroate synthase (24). Class 1 integrons are often embedded in plasmids and transposons, facilitating the lateral transfer of antibiotic resistance genes among bacteria (25).
Nucleotide sequence accession numbers. The whole-genome shotgun project has been deposited in DDBJ/ENA/GenBank under the accession numbers LNSJ00000000 and LNSA00000000. The versions described in this paper are the first versions, LNSJ01000000 and LNSA01000000.

ACKNOWLEDGMENTS
We thank Jonathan Pressman and David Wahman for valuable discussions and assistance for this project.
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