scholarly journals Exfoliative toxin plasmids of bacteriophage group 2 Staphylococcus aureus: sequence homology

1980 ◽  
Vol 30 (2) ◽  
pp. 601-606
Author(s):  
R L Warren
Keyword(s):  
Staphylococcus Aureus ◽  
Sequence Homology ◽  
Gel Electrophoresis ◽  
Deoxyribonucleic Acid ◽  
Agarose Gel ◽  
Agarose Gel Electrophoresis ◽  
Phage Group ◽  
Exfoliative Toxin ◽  
Group 3 ◽  
Group 2

The plasmid contents of seven exfoliative toxin-producing strains of phage group 2 Staphylococcus aureus were analyzed by agarose gel electrophoresis and deoxyribonucleic acid-deoxyribonucleic acid hybridization. All strains were found to contain a large plasmid with a molecular weight of 27 X 10(6) except for strain RW1005. A comparison of the restriction endonuclease cleavage products by agarose gel electrophoresis showed that the number and size distribution of the fragments of all these Tox plasmids were similar, except for pRW002, which appeared to contain two deletions. Deoxyribonucleic acid-deoxyribonucleic acid hybridization studies confirmed that these plasmids were related to a plasmid which carried the genes for exfoliative toxin B and bacteriocin R1 biosynthesis and that they shared some sequence homology with the penicillinase plasmid pI258 isolated from a phage group 3 S. aureus.

scholarly journals Use of plasmid profiles in epidemiologic surveillance of disease outbreaks and in tracing the transmission of antibiotic resistance.

1988 ◽  
Vol 1 (2) ◽  
pp. 228-243 ◽  
Author(s):  
L W Mayer
Keyword(s):  
Antibiotic Resistance ◽  
Gel Electrophoresis ◽  
Deoxyribonucleic Acid ◽  
Disease Outbreaks ◽  
Molecular Size ◽  
Plasmid Profile ◽  
Agarose Gel ◽  
Agarose Gel Electrophoresis ◽  
Bacterial Strains ◽  
Epidemiologic Surveillance

Plasmids are circular deoxyribonucleic acid molecules that exist in bacteria, usually independent of the chromosome. The study of plasmids is important to medical microbiology because plasmids can encode genes for antibiotic resistance or virulence factors. Plasmids can also serve as markers of various bacterial strains when a typing system referred to as plasmid profiling, or plasmid fingerprinting is used. In these methods partially purified plasma deoxyribonucleic acid species are separated according to molecular size by agarose gel electrophoresis. In a second procedure, plasmid deoxyribonucleic acid which has been cleaved by restriction endonucleases can be separated by agarose gel electrophoresis and the resulting pattern of fragments can be used to verify the identity of bacterial isolates. Because many species of bacteria contain plasmids, plasmid profile typing has been used to investigate outbreaks of many bacterial diseases and to trace inter- and intra-species spread of antibiotic resistance.

DNA-mediated transformation in mutants of phage group 2 Staphylococcus aureus

1980 ◽  
Vol 26 (8) ◽  
pp. 938-951 ◽  
Author(s):  
Scott M. Martin ◽  
Marvin Rogolsky
Keyword(s):  
Staphylococcus Aureus ◽  
Cross Resistance ◽  
Antibiotic Resistant ◽  
Phage Group ◽  
Group 3 ◽  
Group 2 ◽  
First Time ◽  
Logarithmic Growth ◽  
Infusion Agar ◽  
Group 1

A large pool of antibiotic resistant and auxotrophic mutants was isolated from the Staphylococcus aureus phage group 2 strains UT0002-19 and UT0017 by (1) antibiotic gradient plates, (2) trimethoprim selection, and (3) nitrosoguanidine mutagenesis, which sometimes was coupled by enrichment with either penicillin or methicillin. Strain UT0002-19 has a chromosomal determinant for exfoliative toxin (ET), which causes "scalded skin syndrome" in man. A few mutants were isolated from the phage group 1 strain UT0080, which also produces ET. Two transformation regimens, called the broth and plate methods, were devised for the phage group 2 strains. They employed 80α as helper phage, and recipient cells were incubated with transforming DNA in the presence of Ca2+. Strain UT0080 was transformed using phage 55 as helper. Maximum competence of the phage group 2 strains occurred during early logarithmic growth in trypticase soy broth, but cells grown overnight on heart infusion agar were also competent. Transformation frequencies of all markers ranged from 10−6 to 10−8. For phage 80α, a multiplicity of infection of 4 was optimal in transforming a mutant of strain UT0002-19. Transformation of gly, lin, met, ole, rif, and ser markers in S. aureus is reported for the first time. Ery and ole markers in all three strains exhibited cross-resistance. Mapping studies, similar to those performed by DNA-mediated transformation in the phage group 3 strain 8325, can now be commenced for phage group 2 strains of S. aureus in order to elucidate the molecular genetics of this medically important bacterium.

Luminography – an Alternative Assay for Detection of von Willebrand Factor Multimers

1988 ◽  
Vol 60 (02) ◽  
pp. 133-136 ◽  
Author(s):  
R Schneppenheim ◽  
H Plendl ◽  
U Budde
Keyword(s):  
Von Willebrand Factor ◽  
Gel Electrophoresis ◽  
Detection Methods ◽  
Agarose Gel ◽  
Agarose Gel Electrophoresis ◽  
Luminescence Assay ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryA luminescence assay was adapted for detection of von Willebrand factor multimers subsequent to SDS-agarose gel electrophoresis and electroblotting onto nitrocellulose. The method is as fast as chromogenic detection methods and appears to be as sensitive as autoradiography without the disadvantages of the latter.

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