title: Interaction of pH and NaCl on enumeration of heat-stressed Staphylococcus aureus.
abstract: The effect of pH level and NaCl concentrations, alone and in combination, on the enumeration of unstressed and heat-stressed cells of three strains of Staphylococcus aureus was determined. A definite narrowing of the optimum pH range for enumeration of both unstressed and heat-stressed cells was observed as the NaCl concentration was increased from 0.0 to 7.5%. Counts of unstressed cells diminished only slightly with increases in NaCl, whereas heat-stressed cells showed a marked sensitivity to NaCl concentrations of 4% and above, regardless of the pH level. Because of this sensitivity to NaCl, recoveries were far poorer than with unstressed cells at NaCl concentrations of 4% and above.
mesh_terms: D000704:Analysis of Variance; D001431:Bacteriological Techniques; D002452:Cell Count; D003470:Culture Media; D004352:Drug Resistance, Microbial; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D012965:Sodium Chloride / Q000494:pharmacology*; D013210:Staphylococcus / Q000187:drug effects / Q000302:isolation & purification*
chemical_list: D003470:Culture Media; D012965:Sodium Chloride