Replica plating and indirect selection of bacterial mutants: isolation of preadaptive mutants in bacteria by sib selection.

Isolation of Pre-Adaptive Mutants in Bacteria by Sib Selection.

IN VITRO TECHNIQUES COUPLED WITH IRRADIATION FOR SELECTION OF BASMATI RICE MUTANTS BE'ITER ADAPTED TO SALINE ENVIRONMENTS

Among different doses of gamma rays, 1.5 kR induced 71.84% callus in Basrnati rice in amodified MS medium and 2% redifferentiation under anon-saline environment, 20% callusing response with 7.5%,2.8% and 2.5% redifferentiation was induced by 2.0 kR at electrical conductivity (EC) of 4,s and 6 dS.m of NaCl respectively, in regeneration medium. A non-irradiated non-saline environment reveale...

A novel strategy to isolate cell-envelope mutants resistant to phage infection: bacteriophage mEp213 requires lipopolysaccharides in addition to FhuA to enter Escherichia coli K-12.

We have developed a direct and efficient strategy, based on a three-step method, to select bacterial cell-envelope mutants resistant to bacteriophage infection. Escherichia coli K-12 strain W3110 underwent classical transposon mutagenesis followed by replica plating and selection for mutants resistant to infection by coliphage mEp213. To verify that phage resistance was due to mutations in the ...

Study of Organic Solvent Tolerance and Increased Antibiotic Resistance Properties in E. coli gyrA Mutants

   Ciprofloxacin is one of the most widely used antibiotics for the treatment of several infections caused by Gram-negative bacteria, like E. coli. Changes in gyrA, encoding GyrA subunit of DNA gyrase, cause the resistance to ciprofloxacin. Some ciprofloxacin resistant gyrA mutants acquired constitutive expression of marRAB operon due to the gaining mutations in marR, a repressor of this operon...

Study of Mutations in the DNA gyrase gyrA Gene of Escherichia coli

Quinolones are a large and widely consumed class of synthetic drugs. Expanded-spectrum quinolones, like ciprofloxacin are highly effective against Gram-negative bacteria, especially Escherichia coli. In E. coli the major target for quinolones is DNA gyrase. This enzyme is composed of two subunits, GyrA and GyrB encoding by gyrA and gyrB, respectively. Mutations in either of these genes cause qu...