Antibiotic Resistance and Hly Plasmids in Serotypes of
            <i>Escherichia coli</i>
            Associated with Porcine Enteric Disease

Jørgensen, Sigrid Tue; Poulsen, Anna-Lise

doi:10.1128/aac.9.1.6

Cited by 11 publications

(4 citation statements)

References 16 publications

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“…Except for a rare report of colicin transfer (15), Hly is transmitted independently of Col and R factors. Hly can also possess fi+ (fertility inhibition) characteristics (54,71,89,91,92) and its introduction into an F' recipient often results in the cells becoming resistant to infection by the F-specific bacteriophage MS2.…”

Section: Genetic Aspectsmentioning

confidence: 99%

Escherichia coli alpha-hemolysin: characteristics and probable role in pathogenicity.

Cavalieri¹,

Bohach²,

Snyder³

1984

Microbiological Reviews

170

106

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HISTORICAL PERSPECTIVE Kayser in 1903 reported that some E. (oli cultures lysed erythrocytes (RBC) (55). He noted that the culture supernatants retained hemolytic activity after being filtered through a Chamberland filter. Dudgeon and Pulvertaft in 1927 also reported hemolytic activity in E. coli cultures (19) but could not demonstrate hemolysin in culture filtrates. They assumed that all activity was associated with the E. coli cell. Several other reports confirmed the existence of cell-associated hemolytic activity (2, 19, 20, 51, 81, 86). Kayser's report of a filterable hemolysin was confirmed in 1960 when Lovell and Rees (64) obtained a bacteria-free hemolysin preparation by filtration of cultures grown in alkaline meat infusion broth. Smith in 1963 was the first to clearly differentiate cellbound and cell-free hemolysin in cultures of E. (oli grown in alkaline meat extract broth (88). He showed that under the same growth conditions some hemolytic strains of E. coli produce cell-free and cell-bound hemolysin simultaneously. Cell-bound hemolysin was not neutralized by antiserum prepared against the cell-free hemolysin, indicating that the two hemolysins might be different. Smith designated the cell-bound hemolytic factor as P-hemolysin and the cell-free factor as oa-hemolysin (AH). This was perhaps an unfortunate designation and has caused some confusion since both the ot-and ,-hemolysins cause 3-hemolysis (clear zone of lysis) around colonies on blood agar plates. Walton and Smith (113) found a third hemolysin (yhemolysin) produced by mutants resistant to nalidixic acid. Hemolysin production by these mutants is enhanced by growth in nalidixic acid. Unlike the cxand 3-hemolysins, the 326

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Section: Genetic Aspectsmentioning

confidence: 99%

Escherichia coli alpha-hemolysin: characteristics and probable role in pathogenicity.

Cavalieri¹,

Bohach²,

Snyder³

1984

Microbiological Reviews

170

106

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“…α-hemolysin plasmids are frequently found in STEC strains producing Stx2e, agents of edema disease in pigs [ 40 ], and in ETEC strains producing heat-stable enterotoxin causing diarrhea in dogs [ 10 ]. The α- hly plasmid pEO5 is closely associated with EPEC O26 strains as diarrheal agents of human infants and calves [ 21 , 41 ].…”

Section: Discussionmentioning

confidence: 99%

Common origin of plasmid encoded alpha-hemolysin genes in Escherichia coli

Burgos

Beutin

2010

BMC Microbiology

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BackgroundAlpha (α)-hemolysin is a pore forming cytolysin and serves as a virulence factor in intestinal and extraintestinal pathogenic strains of E. coli. It was suggested that the genes encoding α-hemolysin (hlyCABD) which can be found on the chromosome and plasmid, were acquired through horizontal gene transfer. Plasmid-encoded α-hly is associated with certain enterotoxigenic (ETEC), shigatoxigenic (STEC) and enteropathogenic E. coli (EPEC) strains. In uropathogenic E. coli (UPEC), the α-hly genes are located on chromosomal pathogenicity islands. Previous work suggested that plasmid and chromosomally encoded α-hly may have evolved independently. This was explored in our study.ResultsWe have investigated 11 α-hly plasmids from animal and human ETEC, STEC and EPEC strains. The size of α-hly plasmids ranges from 48-157 kb and eight plasmids are conjugative. The regulatory gene (hlyR) located upstream of the hlyCABD gene operon and an IS911 element located downstream of hlyD are conserved. Chromosomally-encoded α-hly operons lack the hlyR and IS911 elements. The DNA sequence of hlyC and hlyA divided the plasmid- and chromosomally-encoded α-hemolysins into two clusters. The plasmid-encoded α-hly genes could be further divided into three groups based on the insertion of IS1 and IS2 in the regulatory region upstream of the α-hly operon. Transcription of the hlyA gene was higher than the housekeeping icdA gene in all strains (rq 4.8 to 143.2). Nucleotide sequence analysis of a chromosomally located α-hly determinant in Enterobacter cloacae strain indicates that it originates from an E. coli α-hly plasmid.ConclusionOur data indicate that plasmids encoding α-hly in E. coli descended from a common ancestor independent of the plasmid size and the origin of the strains. Conjugative plasmids could contribute to the spread of the α-hly determinant to Enterobacter cloacae. The presence of IS-elements flanking the plasmid-encoded α-hly indicate that they might be mobile genetic elements.

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“…Strains, plasmids, and bacteriophages. The organisms consisted of 19 naturally occurring Cm-resistant strains, 15 of which have been mentioned in a previous publication (9). The source as well as details of the isolation procedure was reported in the same paper.…”

Section: Methodsmentioning

confidence: 99%

Chloramphenicol Resistance Plasmids in Escherichia coli Isolated from Diseased Piglets

Jørgensen¹

1978

Antimicrob Agents Chemother

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The plasmids in 19 chloramphenicol-resistant Escherichia coli strains of three pig pathogenic antigen types were studied in conjugation and transduction experiments. The plasmids had identical resistance patterns: streptomycin, spectinomycin, sulfonamides, and chloramphenicol (Sm, Sp, Su, Cm) and belonged to IncFII. One plasmid carried ampicillin resistance in addition. Restriction enzyme analysis of the deoxyribonucleic acid from five of the plasmids originating from the same herd showed that their digestion patterns with EcoRI were indistinguishable. EcoRI cleaved the deoxyribonucleic acid of a sixth plasmid from the same herd and displayed nine of the ten bands of the other five plasmids plus an additional six. It appears that the five plasmids with identical restriction patterns have a common origin and may be copies of the same plasmid from which the sixth may have developed. Four strains carried two plasmids each. In two of these strains, a plasmid with a tetracycline marker (Tc), or possibly the tetracycline marker alone, recombined frequently with the Sm Sp Su Cm plasmid without destroying any known function of the latter. The possibility that Tc is carried on a translocation sequence is discussed.

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Antibiotic Resistance and Hly Plasmids in Serotypes of Escherichia coli Associated with Porcine Enteric Disease

Cited by 11 publications

References 16 publications

Escherichia coli alpha-hemolysin: characteristics and probable role in pathogenicity.

Escherichia coli alpha-hemolysin: characteristics and probable role in pathogenicity.

Common origin of plasmid encoded alpha-hemolysin genes in Escherichia coli

Chloramphenicol Resistance Plasmids in Escherichia coli Isolated from Diseased Piglets

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