The use of nucleosides and arginine as alternative energy sources by coagulase-negative staphylococci in view of meat fermentation

The ability of coagulase-negative staphylococci (CNS) to use alternative energy sources in meat may
partially explain their occurrence in fermented meats. Of 61 CNS strains tested, all metabolized adenosine
and inosine in a meat simulation medium (MSM). The ability to catabolize arginine via the arginine
deiminase (ADI) pathway varied between strains. All tested strains of Staphylococcus carnosus and
Staphylococcus epidermidis possessed an arcA gene and showed ADI activity, whereas other species, such
as Staphylococcus equorum and Staphylococcus succinus, did not. Arginine catabolic mobile elements
(ACME), as in the positive control S. epidermidis ATCC 12228, were uncommon and only found in
Staphylococcus xylosus 3PA6 (sausage isolate) and Staphylococcus chromogenes G222 (teat apex isolate).
Monoculture experiments were performed in MSM with S. carnosus 833 and SS3-4, S. xylosus G211, and
S. epidermidis ATCC 12228 and 2S7-4. At all pH values tested (5.3, 5.8, and 6.5), the strains of S. carnosus
catabolized arginine faster than the strains of S. xylosus and S. epidermidis. Only at pH 6.5 could a low ADI
activity be found for S. xylosus G211. Increased ADI activity occurred in the case of the ACME-positive
S. epidermidis ATCC 12228, when compared to the ACME-negative S. epidermidis 2S7-4.

Publication year:2014

Keywords:staphylococci, fermented meat, arginine, adenosine, inosine