ABSTRACT
We report here the genome sequences of two strains of Escherichia coli (ECA-B and ECC-M) that cause bovine mastitis. These strains are known to be associated with persistent and transient mastitis; strain ECA-B causes a transient infection, and ECC-M leads to a persistent infection.
GENOME ANNOUNCEMENT
Intramammary infection (IMI) caused by Escherichia coli in cattle results in a significant burden to animal health and milk production worldwide. Bacterial swimming and swarming of E. coli, in vitro, has been shown to correlate with persistent IMI (1, 2). Proteomic analysis of strains associated with persistent versus transient IMI were assessed previously (1). To further characterize E. coli strains that cause transient or persistent IMI, representative transient (ECA-B) and persistent (ECC-M) strains were sequenced. These strains were originally described by Dogan et al. (2).
Strains were grown to late-log phase in LB medium (10 g Bacto tryptone, 5 g Bacto yeast extract, 5 g NaCl, and 1 liter deionized water) at 37°C. Purified DNA was submitted to the Iowa State University Sequencing Core Lab (Ames, IA, USA) for sequencing using the TruSeq library preparation kit (Illumina, Inc., San Diego, CA, USA) and sequenced using a MiSeq version 3 reagent kit (600 cycles; Illumina, Inc.) on a MiSeq instrument (Illumina, Inc.) according to the manufacturer’s directions. Reads were de novo assembled using Seqman NGen de novo assembler (Lasergene version 12.1; DNAstar, Madison, WI, USA).
Sequencing and assembly of ECA-B resulted in 84 contigs with a maximum length of 467,915 bp, an N50 of 220,891 bp, and an N90 of 44,226 bp. Assembly of ECC-M resulted in 78 contigs with a maximum contig length of 557,037 bp, an N50 of 265,012, and an N90 of 88,795.
Accession number(s).
This whole-genome shotgun sequencing project has been deposited at DDBJ/ENA/GenBank under the accession numbers NHTF00000000 (ECA-B) and NHZH00000000 (ECC-M).
ACKNOWLEDGMENTS
Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendations or endorsement by the U.S. Department of Agriculture.
This work was funded by the U. S. Department of Agriculture (grants 5030-32000-222 and 5030-32000-115).
Footnotes
Citation Thacker TC, Lippolis JD, Brunelle BW, Casey TA, Reinhardt TA, Sacco RE, Holman DB. 2017. Genome sequences of Escherichia coli strains that cause persistent and transient mastitis. Genome Announc 5:e00775-17. https://doi.org/10.1128/genomeA.00775-17.
REFERENCES
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