Growth of Salmonella choleraesuis subspecies diarizonae serovar 61 : k : 1,5,(7) in broth and fresh mutton

Three serovars of Salmonella choleraesuis (IIIb 61:k: 1,5,(7), Enteritidis and Dublin) were grown in broths of pH 5.5 and 6.2 and incubated at 4, 6, 8 or 12 degrees C. Growth in the broth, measured by means of an increase of absorbance, was not observed below 8 degrees C. At 8 and 12 degrees C, the maximum growth rate (mu(max)), lag period and maximum absorbance level (max (abs)) varied according to serovar and pH. In general, serovar IIIb 61:k:1, 5,(7) and serovar Enteritidis grew better than serovar Dublin. The effect o f pH on lag period, seen for serovar IIIb 61:k:1,5,(7) and serovar Enteriti dis at 8 degrees C, was absent at 12 degrees C, while the effect of pH rega rding the mu(max) and the max(abs) was observed also at 12 degrees C. Furth ermore, the growth serovar IIIb 61:k: 1,5,(7) in normal and dark, firm and dry meat at 8 degrees C with ambient air in competition with the natural mi crobial flora was tested in minced meat and chops. Slow growth of serovar I IIb 61:k:1,5,(7) was observed in minced meat. The low virulence and the ord inary growth capabilities indicate that serovar mb 61:k:1,5,(7) will probab ly not represent a serious hazard to the public health. (C) 2000 Elsevier S cience B.V. All rights reserved.