Efficacy of combinations of lactic acid and potassium sorbate against Listeria monocytogenes in chicken stored under modified atmospheres
FOOD MICROBIOLOGY
Authors: Gonzalez-Fandos, Elena; Martinez-Laorden, Alba; Perez-Arnedo, Iratxe
Abstract
The combined effect of lactic acid and potassium sorbate on the growth of L. monocytogenes on chicken legs packaged under modified atmospheres (MAP) and stored at 4 degrees C was evaluated. An extended lag phase and a lower maximum growth rate for psychrotrophs and mesophiles was found in those samples packaged in 20% CO2/80%N-2 and washed with different combinations of lactic acid and potassium sorbate compared to those non-treated with organic acids. Legs packaged in 20%C(O)2/80%N-2 and washed with 3.75% lactic acid 3.75% potassium sorbate showed a significant (p < 0.05) reduction in L. monocytogenes compared to untreated chicken legs packaged in MAP, which were approximately 2.63 log units lower in the first ones after 8 days of storage. Moreover, this treatment was the most effective in decreasing the maximum growth rate of L. monocytogenes. The chicken legs packaged in atmospheres containing 20%CO2/80%N-2, had an extended shelf life, but these atmospheres were not able to reduce L. monocytogenes, thus underlining the need for preventive measures so as to control this pathogen. The immersion of chicken legs in a solution containing 3.75% lactic acid 3.75% potassium sorbate can reduce L monocytogenes populations on fresh chicken packaged in a modified atmosphere.
Xenophagy in cancer
SEMINARS IN CANCER BIOLOGY
Authors: Ammanathan, Veena; Vats, Somya; Abraham, Irine Maria; Manjithaya, Ravi
Abstract
Macroautophagy (herein autophagy) is an intracellular pathway in which cytoplasmic components are captured by double-membrane vesicles (autophagosomes) that eventually fuse with lysosomes to degrade the cargo. Basal levels of autophagy in all eukaryotic cells maintain cellular homeostasis and under conditions of stress, organelles and proteins not essential for survival are degraded. Apart from these functions, cargoes like aggregated proteins, damaged organelles and intracellular pathogens, which are otherwise harmful to cells, are also selectively captured by autophagy and are destined for degradation. In terms of infectious diseases, pathogens are cleared by a specific form of autophagy known as xenophagy. This lysosomal mediated degradation of pathogens also increases the antigen presentation of cells thereby inducing a further immune response. The process of xenophagy provides a broad spectrum of defense mechanism to capture bacterial, viral and protozoan pathogens. However, pathogens have developed ingenious mechanisms to modulate xenophagy to enhance their intracellular survival. Meanwhile, certain pathogens also induce deleterious effects such as chronic inflammation and overexpression of oncogenes in the host system. This over time can increase the susceptibility of the host for tumorigenesis. Hence targeting tumor through anti-microbial mechanisms like xenophagy could be a novel strategy for combinatorial anti-cancer therapy. The recent developments in understanding the role of xenophagy in combating cancer causing pathogens will be discussed in this review.