Increase in microbial contamination of defeathering machinery in a poultry processing plant after changes in the method of processing

Bacterial contamination on rubber picker fingers before, during, and after processing

Numbers of bacteria on rubber picker fingers collected from processing plants for 3 industrial processors were assessed in 3 separate trials for each plant. After 5 d in use, picker fingers were removed from the front, center, and back of an inline picker, including locations to the right and left of the processing line. Assessment indicated that the levels of bacteria present immediately after processing vary widely. Bacterial density on picker finger sections ranged from log(10) cfu = 0 to 5.41 in 2 of the 3 processing plants from which picker fingers were obtained. Higher counts (ranging from log(10) cfu = 3.23 to 7.33) were assessed on picker fingers from a third plant. The effect of location of fingers in the picker machine on bacterial counts was tested in 2 trials at each of 2 processing plants. There was no difference between the counts on fingers collected from the right or left of the picker machine for either plant. There was a difference (P < 0.05) among the counts on fingers collected in the forward direction, from front, center, and exit end, for 1 of the plants. No bacterial growth occurred in samples from new rubber picker fingers obtained from any of the processors. On rubber fingers with initially lower bacterial counts, microbial growth increased when incubated without additional disinfectant treatment. The bacterial population on used fingers incubated for 3 d significantly increased (P < 0.05) above that of bacteria on inline fingers. These results indicate that intervention early in the picking process could enhance sanitation practices and pathogen control.

Characterization of Staphylococcus aureus isolated from poultry meat in Spain

Ninety-six Staphylococcus aureus isolates from retail chicken carcasses in Spain were characterized using cultural and biochemical tests. The strains were phage typed with the international bacteriophage set for typing S. aureus of human origin. Eighty-eight (91.7%) strains were of the poultry ecovar. Strains of human ecovar were not found. These facts are congruent with findings of other authors. Ninety (93.7%) strains were phage typeable. Lysis by phages of Group III was the most frequent with 66 (68.7%) sensitive strains. Twenty-eight (29.2%) strains were sensitive at 100 routine test dilution (RTD) and only 16 (16.7%) at RTD. By using reversed phage typing, we managed to increase the number of phage typeable strains by 46 (47.9%). More than one S. aureus phage type was detected in 14 (35%) carcasses, which emphasizes the convenience of subtyping several S. aureus isolates from the same food sample in epidemiological studies. Two phage patterns (75/84 and 6/1030/ W57) were the most common. The S. aureus isolates were closely related, as 78 strains showed the most common or indistinguishable (<2 phage reaction differences) phage patterns.