Prevalence and pathogenicity of Aeromonas spp., Escherichia coli and Salmonella spp. in fresh, chilled and frozen beef frankfurters.

摘要

Sausage samples were collected on the day of production from a meat processing plant. From a batch, 24 samples were collected and 2 were subjected to analysis on that day itself. Ten samples were stored at 4-7 degrees C and 2 samples each were tested on alternate days up to 10th day. Twelve samples were stored frozen at -20 degrees C and 2 each were tested at 15 days interval up to 90th day. Study was repeated on samples collected from 6 batches and a total of 144 samples were analysed. Study revealed that 25.0, 23.3 and 9.7% of fresh, chilled and frozen samples, respectively had Aeromonas spp.; 3 species of Aeromonas isolated were A. hydrophila, A. sobria and A. caviae. Single isolate of A. hydrophila obtained from the chilled samples was hemolytic and hemagglutinating. Seventy five % each of A. sobria and A. caviae from chilled samples were hemolytic and 25% each were hemagglutinating. Among A. sobria isolates, 33.3% and 66.7%, respectively were hemolytic and hemagglutinating. Fifty % isolates of A. caviae were hemolytic and hemagglutinating. Escherichia coli was present only in chilled samples (21.7%). Serotyping revealed that 84.6% of isolates belonged to O< sub>2 serotype coming under enterohemorrhagic group. Among these isolates 61.5% was Congo red binding indicating their invasive nature. Salmonella was absent in all the fresh, chilled and frozen samples tested.