The Nature of Arginine Auxotrophy in Cutaneous Populations of Staphylococci

L-Arginine was required for growth by a high percentage of strains of Staphylococcus species that were niche-specific and/or host-specific, but was usually not required for growth by species showing a wide host range. Growth stimulation patterns with arginine intermediates indicated that most of the auxotrophic strains had blocks in an early step(s) in arginine biosynthesis. These strains were designated phenotypically as Arg(CHG) according to the Salmonella typhimurium classification scheme. Staphylococcus simulans strains appeared to be either ArgA or Arg I. The ArgI strains of S. simulans and S. capitis had moderate to high ornithine carbamoyltransferase (EC 2.1.3.3) activities and therefore could not be designated as argI mutants. ArgI strains in other species had no or very low ornithine carbamoyltransferase activities. All of the natural Staphylococcus auxotrophs tested grew in the presence of L-citrulline and had moderate to high argininosuccinase (EC 4.3.2.1) activities. Arginine auxotrophs of species with a wide host range were often capable of reverting to arginine-independent or complete prototrophic growth, whereas auxotrophs of species that tended to be niche-specific and/or host-specific were incapable of reversion to arginine-independence, even in the presence of various mutagens. A relationship between the nature of arginine auxotrophy and habitat is suggested.