The effect of a commercial UV disinfection system on the bacterial load of shell eggs

Aims: To study the effect of UV irradiation on the bacterial load of shell eggs and of a roller conveyor belt. Methods and Results: The natural bacterial load on the eggshell of clean eggs was significantly reduced by a standard UV treatment of 4.7 s; from 4.47 to 3.57 log CFU per eggshell. For very dirty eggs no significant reduction was observed. Eggs inoculated with Escherichia coli and Staphylococcus aureus (4.74 and 4.64 log CFU per eggshell respectively) passed the conveyor belt and were exposed to UV for 4.7 and 18.8 s. The reduction of both inoculated bacteria on the eggshell was comparable and significant for both exposure times (3 and 4 log CFU per eggshell). Escherichia coli was reduced but still detectable on the conveyor rollers. The internal bacterial contamination of eggs filled up with diluent containing E. coli or S. aureus was not influenced by UV irradiation. Conclusions: There is a significant lethal effect of UV irradiation on the bacterial contamination of clean eggshells and recent shell contamination, contamination of rollers can be controlled and the internal contamination of eggs is not reduced. Significance and Impact of the Study: The penetration of UV into organic material appears to be poor and UV disinfection can be used as an alternative for egg washin

Surface decontamination treatments for improving the safety of meat and poultry

The microbiological safety of raw beef and poultry products continue to be one of the major concerns of the meat industry. In 2011, an estimated 9.4 million illnesses, 55,961 hospitalizations, and 1,351 deaths were attributed to known foodborne pathogens in the USA including Norovirus caused the most illnesses; nontyphoidal Salmonella spp., norovirus, Campylobacter spp., and Toxoplasma gondii caused the most hospitalizations; and nontyphoidal Salmonella spp., T. gondii, Listeriamonocytogenes, and norovirus caused the most deaths [Scallan et al. (Emerg Infect Dis 17:7–15, 2011)]. Several factors influence the incidence of pathogens in the meat and poultry food supply, some of the more important factors are livestock production practices that may inadvertently foster pathogen contamination; the emergence of “new” and antibiotic-resistant pathogens in the environment; increased manipulation and handling and accelerated processing of carcasses and raw materials; modification of traditional processing practices and greater complexity of manufacturing procedures and equipment; a more complex distribution and food preparation system that increases the risk of foodborne disease; more discriminate and selective pathogen detection methods to improve confirmation and trace-back of contaminated product; and consumer habits that represent inappropriate food handling and preparation practices [Keeton and Eddy (Preharvest and postharvest food safety—contemporary issues and future directions. Blackwell, Ames, 2004)]. The surface decontamination treatments of meat and poultry could improve the safety of these products and help to reduce foodborne illnesses. Details of some surface decontamination treatments of raw meat and poultry are discussed in this review. © 2014, Springer Science+Business Media New York

STAT3-dependent VEGF production from keratinocytes abrogates dendritic cell activation and migration by arsenic: a plausible regional mechanism of immunosuppression in arsenical cancers

[[abstract]]Arsenic remains an important environmental hazard that causes several human cancers. Arsenic-induced Bowen’s disease (As-BD), a skin carcinoma in situ, is the most common arsenical cancer. While great strides have been made in our understanding of arsenic carcinogenesis, how host immunity contributes to this process remains unknown. Patients with As-BD have an impaired contact hypersensitivity response. Although impaired T cell activation has been well-documented in arsenical cancers, how dendritic cell (DC), the key cell regulating innate immunity, regulates the immune response in arsenical cancers remains unclear. Using myeloid derived DC (MDDC) from patients with As-BD and normal controls as well as bone marrow derived DC (BMDC) from mice fed with or without arsenic, we measured the migration of DC. As-BD patients showed an impaired CCL21-mediated MDDC migration in vitro. Arsenic-fed mice had defective DC migration towards popliteal lymph nodes when injected with allogenic BMDCs via foot pad. Using skin from As-BD and normal controls, we found an increased expression of STAT3, a transcriptional factor contributing to impaired DC activation. Arsenic induced STAT3 activation and the production of VEGF in keratinocytes. The increase in VEGF was blocked by inhibiting STAT3 with RNA interference or pharmaceutically with JSI-124. While VEGF by itself minimally induced the expression of CD86 and MHC-II in MDDC, arsenic induced-MDDC activation was abolished by VEGF pretreatment. We concluded that the STAT3-VEGF axis in keratinocytes inhibits DC migration in the microenvironment of As-BD, indicating that cellular interactions play an important role in regulating the disease course of arsenical cancers