ISOLATION OF TRICARBOXYLIC ACID TRANSPORT-NEGATIVE MUTANTS OF SALMONELLA TYPHIMURIUM

Regulation of branched-chain amino acid biosynthesis in Salmonella typhimurium: isolation of regulatory mutants.

5',5',5'-Trifluoro-dl-leucine inhibited the activity of alpha-isopropylmalate synthetase (the initial enzyme unique to leucine biosynthesis) as well as the growth of Salmonella typhimurium. Mutants of S. typhimurium resistant to the analogue were isolated and characterized. In most cases, they overproduced and excreted leucine or leucine, valine, and isoleucine as a result of an alteration in t...

Proline Mutants of Salmonella Typhimurium.

CCORDING to previous analyses of 16 proline-requiring mutants of SalmonA d l a typhimurium, made genetically by NIELSEN (DEMEREC et al. 1954) and biochemically by JSANAZIR (1956; DEMEREC et al. 1955), the mutants fell into at least three groups. Recently, the number of proline-requiring mutants in our collection was increased to more than 200, and useful new techniques were devised or adapted f...

Salmonella typhimurium proline mutants.

Isolation and Detection of Virulence factors of Salmonella typhimurium and Salmonella enteritidis

Plasmids play an important role in the virulence and antibiotic resistance of Salmonella. Salmonella carry plasmids having different size and number. Plasmid profile analysis of single isolates of Salmonella typhimurium and Salmonella enteritidis revealed the presence of 4- plasmid profiles. Salmonella serovars produce several Type III secretions including Sop-E and Sop –B. Soap E is detected b...

6-Aminonicotinamide-resistant mutants of Salmonella typhimurium.

Resistance to the nicotinamide analog 6-aminonicotinamide has been used to identify the following three new classes of mutants in pyridine nucleotide metabolism. (i) pncX mutants have Tn10 insertion mutations near the pncA locus which reduce but do not eliminate the pncA product, nicotinamide deamidase. (ii) nadB (6-aminonicotinamide-resistant) mutants have dominant alleles of the nadB gene, wh...