Complete Genome Sequence of the Triclosan- and Multidrug-Resistant Pseudomonas aeruginosa Strain B10W Isolated from Municipal Wastewater.

Here, we report the complete genome sequence of the triclosan- and multidrug-resistant Pseudomonas aeruginosa strain B10W, obtained from municipal wastewater in Hawaii. The bacterium has a 6.7-Mb genome, contains 6,391 coding sequences and 78 RNAs, with an average G+C content of 66.2 mol%.

GENOME ANNOUNCEMENT

Pseudomonas aeruginosa is an important opportunistic pathogen that exhibits high intrinsic resistance to biocides and antibiotics (1). Triclosan is a biocide widely used in both clinical and consumer product settings (2). Recent identification of a cellular target of triclosan, the enoyl-acyl carrier protein reductase (ENR) (FabI) (3, 4), has cast significant doubt on its usage as a biocide. Previous studies have shown that P. aeruginosa is intrinsically resistant to triclosan due to the activities of multiple efflux pumps (5) and the presence of an alternative ENR, FabV, that is highly resistant to triclosan (6).

P. aeruginosa is ubiquitously present in the environment, including municipal wastewater (7). Although the biogeography of fluorescent Pseudomonas strains from soils has been examined in some detail (8), few studies have examined environmental P. aeruginosa isolates (9). The Pseudomonas aeruginosa strain B10W was isolated from municipal wastewater collected in Honolulu, Hawaii, USA, using LB agar supplemented with triclosan (10 μg/mL). Antibiotic susceptibility tests showed that this bacterium exhibited resistance to tetracycline (20 µg/mL), chloramphenicol (10 μg/mL), kanamycin (100 μg/mL), ampicillin (100 μg/mL), and nalidixic acid (20 μg/mL). The B10W genomic DNA was extracted from overnight culture using a GenElute bacterial genomic DNA kit (Sigma). The genomic DNA was subjected to PacBio SMRT cell sequencing. The sequence reads were assembled into a single 6.7-Mb contig using HGAP assembly 3. The contig was verified as circular using Gepard version 1.3.1. The circular contig was reassembled to polish the assembly. The mean sequencing coverage was 118.8-fold, with accuracy greater than 99.99%.

The automated annotation of the B10W genome was performed using the RASTtk server (10), which predicted 6,391 coding sequences, including 78 RNAs. Several multidrug efflux pumps of the resistance nodulation cell division (RND) family, which were previously detected in P. aeruginosa strains, were detected in the B10W genome. These included MexAB-OprM, MexCD-OprJ, and MexEF-OprN (11). The MexJK (12) and TriABC-OpmH (13) efflux pumps, however, were not detected. Other efflux pumps detected include CmeABC, which was previously found in Campylobacter jejuni (14), and the CzcC superfamily for heavy metal resistance, which was frequently detected in soil bacteria (15). Sequence-based searches done using the Resfinder (16) detected five acquired resistance genes in the B10W genome, encoding resistance to chloramphenicol, aminoglycoside, beta-lactams, and fosfomycin.

Accession number(s).

The complete nucleotide sequence of the P. aeruginosa strain B10W genome was deposited in GenBank under accession number CP017969.