Whole-Genome Sequence of Escherichia coli Serotype O157:H7 Strain PA20

Abstract

Escherichia coli serotype O157:H7 strain PA20 is a Pennsylvania Department of Health clinical isolate. It has been used to study biofilm formation in O157:H7 clinical isolates, where the high incidence of prophage insertions in the mlrA transcription factor disrupts traditional csgD biofilm regulation. Here, we report the complete PA20 genome sequence.

Sulfamethoxazole – Trimethoprim represses csgD but maintains virulence genes at 30°C in a clinical Escherichia coli O157:H7 isolate

“…Such an inversion would miss-pair the Att sites on opposing ends of the chimeric Sp4 and Sp14 and prevent circularization, consistent with the results here. Interestingly, a second inversion with termini in Sp9 and Sp12 was also predicted in that study [ 46 ] but our finding of circularized forms of Sp9 here refutes that conclusion. There was also no product generated in our study by outward facing primers located on the ends of SpLE4, indicating no excision and amplification of the LEE EPA1 (primers in S1 Table ; results not shown).…”

“…Unlike Sakai, circularized forms of Sp4 and Sp14 were not detected in PA20. Though an unambiguous assembly was not possible, the recently published complete genome sequence of strain PA20 [ 46 ] predicts that a large chromosomal inversion had occurred between prophage elements Sp4 and Sp14. Such an inversion would miss-pair the Att sites on opposing ends of the chimeric Sp4 and Sp14 and prevent circularization, consistent with the results here.…”

“…coli serotype O157:H7 PA20 is a Stx1+/Stx2+ clinical isolate from the PA Department of Health that has been studied extensively in our laboratory [ 35 , 38 , 45 ]. The entire genome sequence of strain PA20 was recently reported, deposited in GenBank [GenBank Accession # CP017669 (genome) and CP017670 (plasmid)] [ 46 ], and showed strong similarity to strain Sakai. NEB 5-alpha (New England Biolabs, Inc) and One Shot PIR1 (Invitrogen) were used as E .…”

Escherichia coli Serotype O157:H7 PA20R2R Complete Genome Sequence

“…Although clinical strains can carry both modifications, strains with only prophage insertions are clearly better adapted for transitioning back to the environment ( 5 ). We previously reported a strong biofilm-producing strain, 20R2R, isolated during agar passage of strain PA20, a clinical isolate with wild-type rpoS and a prophage in mlrA ( 6 , 7 ). Partial 20R2R characterization revealed excision of the prophage from the parental mlrA making strain 20R2R a valuable strain for studying genetic responses of O157:H7 transitioning between the host and environment ( 8 ).…”

Sulfamethoxazole – Trimethoprim Represses csgD but Maintains Virulence Genes at 30°C in a Clinical Escherichia coli O157:H7 Isolate

“…coli serotype O157:H7 PA20 is a Stx1+/Stx2+ clinical isolate from the PA Department of Health that has been studied extensively in our laboratory [35,38,45]. The entire genome sequence of strain PA20 was recently reported, deposited in GenBank [GenBank Accession # CP017669 (genome) and CP017670 (plasmid)] [46], and showed strong similarity to strain Sakai. NEB 5-alpha (New England Biolabs, Inc) and One Shot PIR1 (Invitrogen) were used as E. coli host strains for www.videleaf.com intermediary cloning steps.…”