Chlorine Inactivation of Salmonella Kentucky Isolated from Chicken Carcasses: Evaluation of Strain Variation

Abstract

The current study was undertaken to evaluate chlorine resistance among strains of Salmonella Kentucky isolated from chicken carcasses. Selected strains (n = 8) were exposed to 30 ppm of chlorine in 10% buffered peptone water (pH 7.4) for 0 to 10 min at 4°C and 150 rpm. The initial level (mean ± SD) of Salmonella Kentucky was 6.18 ± 0.09 log CFU/ml and did not differ (P > 0.05) among strains. A two-way analysis of variance indicated that the level of Salmonella Kentucky in chlorinated water was affected (P < 0.05) by a time by strain interaction. Differences among strains increased as a function of chlorine exposure time. After 10 min of chlorine exposure, the most resistant strain (SK145) was 5.63 ± 0.54 log CFU/ml, whereas the least resistant strain (SK275) was 3.07 ± 0.29 log CFU/ml. Significant differences in chlorine resistance were observed for most strain comparisons. Death of Salmonella Kentucky was nonlinear over time and fitted well to a power law model with a shape parameter of 0.34 (concave upward). Time (minutes) for a 1-log reduction of Salmonella Kentucky differed (P < 0.05) among strains: >10 min for SK145, 6.0 min for SK254, 1.5 min for SK179, and 0.3 to 0.65 min for other strains. Results of this study indicate that strain is an important variable to include in models that predict changes in levels of Salmonella Kentucky in chlorinated water.

Campylobacter through poultry processing: selection and survival

“…This suggests that the Campylobacter isolate used in testing is an important variable to be considered when assessing the effect of intervention steps in poultry processing. This is in agreement with other reports using Salmonella Kentucky and S. Typhimurium which concluded that the strain of Salmonella is an important independent variable for inclusion in models (Mohamed et al, 2015;Oscar et al, 2013). Differences in inactivation curve shape were noted for some CCs.…”

Role of Free-Ranging Synanthropic Egyptian Geese (Alopochen aegyptiaca) as Natural Host Reservoirs for Salmonella spp. in Germany

“…Different former investigations tested much higher chlorine concentrations to disinfect different organic material such as carcasses or seeds contaminated with Salmonella spp. with more or less success [57,58]. All authors reported on the chlorine resistance of different Salmonella strains, thereby demanding future detailed investigations on disinfection strategies.…”

“…Which organic material is disinfected by chlorination seems to be decisive, but in contrast the temperature seems to have no influence on Salmonella survival [57,[59][60][61]. Organic materials with high protein contents are prone to promote bacterial survival, as especially amino acids (aa) are binding free chlorine molecules, thus reducing their ability to kill bacteria [58]. Salmonella spp.…”