To evaluate the growth/survival of natural flora and Aeromonas hydrophila on refrigerated normal low (pork) and high (turkey) pH meats packaged in modified atmospheres, A. hydrophila was inoculated onto fresh pork and turkey meat slices. Inoculated and control samples were packaged in modified atmospheres (100% N-2, 20/80 and 40/60 CO2/O-2) or in air in plastic bags and kept at I and 7 degreesC. Samples packaged in air showed a similar microbiological pattern to that usually observed in fresh meat stored aerobically Packaging in modified atmosphere produced a strong inhibition of bacterial growth at 1 degreesC, particularly in samples stored in CO2/O-2 enriched atmospheres. Aeromonas hydrophila grew on turkey and pork meat stored in 100% N-2 at I and 7 degrees C. Likewise, growth of this bacterium was detected on turkey stored in 20/80 CO2/O-2 at 7 degreesC. No growth was observed in 40/60 CO2/O-2 in any meat at both temperatures assayed (C) 2000 Academic Press.