Microbial quality of ostrich carcasses produced at an export-approved South African abattoir.

The aim of this study was to evaluate the microbial quality of ostrich carcasses produced in a South African export-approved ostrich abattoir. Ninety surface samples were collected from 30 ostrich carcasses at three processing points in the abattoir: after skinning, after evisceration, and after chilling. Samples were evaluated for aerobic plate counts, for levels of Pseudomonas spp., Enterobacteriaceae, and Staphylococcus aureus, and for the presence of Escherichia coli. Surface counts (means +/- standard deviations) at postskinning, postevisceration, and postchilling processing points were, respectively, 4.32 +/- 0.62, 4.21 +/- 0.63, and 4.57 +/- 0.48 log CFU/cm2 for total aerobes; 2.82 +/- 1.65, 2.86 +/- 1.53, and 3.75 +/- 0.94 log CFU/ cm2 for Pseudomonas spp.; 2.89 +/- 0.78, 2.90 +/- 0.53, and 2.38 +/- 0.67 log CFU/cm2 for S. aureus; and 2.55 +/- 1.53, 2.78 +/- 1.31, and 2.73 +/- 1.46 log CFU/cm2 for Enterobacteriaceae. Statistically significant differences were detected between the counts for the postskinning and postchilling processing points and between the counts for the postevisceration and postchilling processing points for total aerobes, Pseudomonas spp., and S. aureus. Of practical significance was the increase in Pseudomonas spp. counts on samples collected after chilling. Seventeen of 90 samples (18.8%) tested positive for E. coli. Counts for E. coli-positive samples ranged from 1.0 to 3.79 log CFU/cm2, with a mean count of 2.15 +/- 0.94 log CFU/cm2. The majority of the samples testing positive for E. coli were collected after evisceration.

Bacterial populations associated with the dirty area of a South African poultry abattoir.

Bacterial populations associated with three sample types from the neck region of poultry carcasses in the dirty area of an abattoir were characterized. Sample types before and after scalding were skin only, feathers only, and a skin and feather combination. The neck skin of carcasses after the defeathering processing stage was also sampled. Bacterial populations associated with water from the scald tank, rubber fingers at the exit of the defeathering machine, and air in the dirty area were also characterized. Bacterial colonies (751) were randomly isolated from yeast extract-supplemented tryptone soya agar plates exhibiting 30 to 300 colonies. Micrococcus spp. were isolated in the highest proportion from pre-and postscalded carcass samples (63.5 to 86.1% of isolates), regardless of the sample type. Conversely, Enterobacteriaceae (40.3%), Acinetobacter (19.4%), and Aeromonas/Vibrio (12.5%) species predominated on neck skin samples taken from mechanically defeathered carcasses. Isolates from the rubber fingers were, however, predominantly Micrococcus spp. (94.4%). Bacterial groups isolated in the highest proportion from scald tank water samples were Micrococcus spp. (38.3%), species of Enterobacteriaceae (29.1%), and lactic acid bacteria (17.0%). Corynebacterium spp., species of Enterobacteriaceae, and Micrococcus spp. were dominant on air settle plates.

Large-scale purification of the mycotoxins aflatoxin B1, B2 and G1.

The isolation and purification of gram quantities of the important mycotoxins aflatoxin B1, B2 and G1 are described. The method involves final purification on a Waters Prep LC-500 instrument, loaded with silica cartridges, and elution with chloroform.