An Accurate Method for Estimating Sizes of Small and Large Plasmids and DNA Fragments by Gel Electrophoresis

Rochelle, Paul A.; Fry, John C.; Day, Martin J.; Bale, M. J.

doi:10.1099/00221287-132-1-53

Cited by 69 publications

(64 citation statements)

References 18 publications

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“…Gels were stained in 2 mg/ml ethidium bromide (Sigma, Brondb, Denmark), illuminated with ultraviolet light at 254 nm using an UV transilluminator (UVP, model TS-40, San Gabriel, CA, USA) and photographed with a Polaroid Land Camera (Polaroid, MP-4, SigmaAldrig, Broenby, Denmark). Plasmid mobilities were calculated relative to the reference plasmids in E. coli strains V517 (Macrina, 1978) and 39R861 (Threlfall et al, 1986), and sizes were estimated in accordance with the methods of Rochelle et al (1986). Coiled covalently closed and open circular DNA molecules were differentiated according to Hintermann et al (1981).…”

Section: Methodsmentioning

confidence: 99%

Multi-locus sequence typing and plasmid profile characterization of avian pathogenicEscherichia coliassociated with increased mortality in free-range layer flocks

et al. 2011

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Avian pathogenic Escherichia coli strains originating from 10 free-range layer flocks were characterized by multi-locus sequence typing and plasmid profile analysis to investigate their phylogenetic relationship and diversity, respectively. In addition to colibacillosis, all flocks tested positive for antibodies against avian metapneumovirus (aMPV) during production, and six of the flocks were concurrently affected by histomonosis. Accumulated average mortality for flocks concurrently affected by colibacillosis and histomonosis made up 17.4%, while the average mortality for E. coli-infected flocks was 16.5%. A total of eight different sequence types (STs) and 47 different plasmid profiles were demonstrated among the E. coli isolates. Within each flock between one and four different STs and between three and 13 different plasmid profiles were demonstrated. A statistical significant difference in STs and plasmid profile diversity of the population of E. coli was not demonstrated between flocks affected by histomonosis compared with histomonosis-free flocks. Only minor clonal diversity was demonstrated for each flock, and in all but one flock colibacillosis started before antibodies against aMPV were detected. All isolates, except two, carried plasmids greater than 100 kb, but only a single plasmid replicon type, IncFIB, was demonstrated, suggesting plasmids representing this type might represent a common pathogenicity factor for the different STs of E. coli. Within each flock a clonal tendency was observed, indicating that only certain clones of E. coli possess a significant pathogenic potential. These clones act as primary rather than secondary pathogens, resulting in colibacillosis without predisposing factors, including histomonosis and aMPV.

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Section: Methodsmentioning

confidence: 99%

Multi-locus sequence typing and plasmid profile characterization of avian pathogenicEscherichia coliassociated with increased mortality in free-range layer flocks

et al. 2011

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“…Visualization was made by staining with ethidium bromide (Sigma, 2 pg ml-' distilled water or 3 pg ml-' gel) followed by exposure to UV-light (254 nm) (Olsen et al 1990). Approximate molecular size of the plasmids was estimated from the migration patterns of supercoiled plasmids in 2 reference strains of Escherichia coli, V517 (Macrina et al 1978) and 39R861 (Threlfall et al 1986), using the regression equation recommended by Rochelle et al (1985).…”

Section: Lysis Of Dnamentioning

confidence: 99%

Characterization of isolates of Flavobacterium psychrophilum associated with coldwater disease or rainbow trout fry syndrome:phenotypic and genomic studies

Lorenzen¹,

Dalsgaard²,

Bernardet³

1997

Dis. Aquat. Org.

107

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Isolates of Flavobacterium psychrophiluln (formerly Cytophaga psychrophila and Flexlbacter psychrophilus) mainly originating from clinical outbreaks of either coldwater disease (CWD) or rainbow trout fry syndrome (RTFS) were studied for selected biochemical, physiological, rnorphological and genomic characteristics, and compared with previously characterized French and American strains. DNA hybridization studies showed that the Danish isolates were highly related to the type strain, F. psychrophilum NCIMB 1 9 4 7~ Plasmid profiling of Danish isolates and those from other European countries revealed differences, which might be related to differences in pathogenicity. European ~solates originating from clinical outbreaks of either RTFS or CWD usually harboured one plasmid of 3.2 kb, whereas isolates originating from fish with different or no disease slgns had other profiles. Phenotypically, the Danish isolates appeared very homogeneous and shared most characteristics with the type strain, and with French and American strains studied by other authors. Further studies on the importance of the plasmids and the proteolytic activities of the bacterium might help in elucidating possible virulence factors.

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“…Plasmid mobilities were calculated relative to reference plasmids in E. coli 39R361 (Threlfall et al, 1986) and E. coli V517 (Macrina et al, 1978) according to a previously reported method for size estimation (Rochelle et al, 1985).…”

Section: Plasmid Dna Analysismentioning

confidence: 99%

Phenotypic and genotypic characters of isolates ofPasteurella multocidaobtained from back‐yard poultry and from two outbreaks of avian cholera in avifauna in Denmark

Christensen¹,

Dietz

Bisgaard³

1998

Avian Pathology

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Two outbreaks of fowl cholera in the avifauna in Denmark, affecting primarily eiders but also cormorants, gulls and oyster-catchers were shown to be caused by the same clone of Pasteurella multocida ssp. multocida by restriction enzyme analysis (REA) and ribotyping, using the enzymes HpaII and HhaI and phenotypic characterization. This observation indicated spread by migratory birds. It was shown that the outbreak clone was closely related to isolates of Pasteurella multocida ssp. multocida obtained from back-yard poultry in Denmark, including chickens, pheasants, turkeys and ducks. The only detectable difference between the outbreak clone and some of these strains concerned the size of one fragment. These results indicate a possible exchange of P. multocida ssp. multocida between populations of wild birds and back-yard poultry.Among the DNA fingerprinting methods used, restriction enzyme analysis offered the highest discrimination among thirty strains obtained from back-yard poultry. The restriction enzymes HpaII and HhaI generated almost the same number of profile types, 17 and 15 respectively, but only HpaII differentiated the outbreak clone from the group of closely related strains isolated from back-yard poultry. Ribotyping, using the same enzymes, resulted in 12 and 10 different profile types, respectively. The outbreak isolates did not harbour any plasmids, while six out of the 30 strains originating from back-yard poultry (20%) carried a cryptic plasmid of approximately 3.4 kb.

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An Accurate Method for Estimating Sizes of Small and Large Plasmids and DNA Fragments by Gel Electrophoresis

Cited by 69 publications

References 18 publications

Multi-locus sequence typing and plasmid profile characterization of avian pathogenicEscherichia coliassociated with increased mortality in free-range layer flocks

Multi-locus sequence typing and plasmid profile characterization of avian pathogenicEscherichia coliassociated with increased mortality in free-range layer flocks

Characterization of isolates of Flavobacterium psychrophilum associated with coldwater disease or rainbow trout fry syndrome:phenotypic and genomic studies

Phenotypic and genotypic characters of isolates ofPasteurella multocidaobtained from back‐yard poultry and from two outbreaks of avian cholera in avifauna in Denmark

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