Older Adult Consumer Knowledge, Attitudes, and Self-Reported Storage Practices of Ready-to-Eat Food Products and Risks Associated with Listeriosis.

Consumer implementation of recommended food safety practices, specifically relating to time and temperature control of ready-to-eat (RTE) food products associated with listeriosis are crucial. This is particularly the case for at-risk consumers such as older adults, given the increased listeriosis incidence reported internationally among adults aged ≥60 years. However, data detailing older adults' cognitive risk factors associated with listeriosis are lacking. Combining data about knowledge, self-reported practices, and attitudes can achieve a cumulative multilayered in-depth understanding of consumer food safety behavior and cognition. This study aims to ascertain older adults' cognition and behavior in relation to domestic food handling and storage practices that may increase the risks associated with L. monocytogenes. Older adults (≥60 years) (n = 100) participated in an interview and questionnaire to determine knowledge, self-reported practices, and attitudes toward recommended practices. Although the majority (79%) had positive attitudes toward refrigeration, 84% were unaware of recommended temperatures (5°C) and 65% self-reported "never" checking their refrigerator temperature. Although most (72%) knew that "use-by" dates indicate food safety and 62% reported "always" taking note, neutral attitudes were held, with 67% believing it was safe to eat food beyond use-by dates and 57% reporting doing so. Attitudes toward consuming foods within the recommended 2 days of opening were neutral, with 55% aware of recommendations and , 84% reporting that they consume RTE foods beyond recommendations. Although knowledgeable of some key practices, older adults self-reported potentially unsafe practices when storing RTE foods at home, which may increase risks associated with L. monocytogenes. This study has determined that older adults' food safety cognition may affect their behaviors; understanding consumer food safety cognition is essential for developing targeted food safety education.

Immune changes during acute cold/restraint stress-induced inhibition of host resistance to Listeria.

Experiments were conducted to delineate the cellular changes modulated by acute cold/restraint stress (ACRS), a physical and psychological stressor, in response to a Listeria monocytogenes(LM) infection. In addition to wild type (WT) BALB/c mice, CD4-deficient (CD4-/-) BALB/c mice, which have no effective adaptive immunity, were used to determine the involvement of adaptive versus innate immunity. ACRS-induced suppression of host resistance to LM was not observed in CD4-/- mice, suggesting the involvement of CD4+T cells in the acute cold/restraint stress (ACRS)-induced inhibition. The in vivo splenic leukocyte phenotypes and activities of WT BALB/c mice after infection and in vitro lymphocyte responses to heat-killed LM (HKLM) also were examined. There were no significant differences in the numbers of splenic T and B lymphocytes, natural killer cells, macrophages, or neutrophils between nonstressed and ACRS-treated WT mice. However, higher levels of activated T cells and non-T lymphocytes were observed in the ACRS-treated mice; beta-adrenergic receptor (beta-ADR) antagonists (propranolol and atenolol) eliminated these elevated levels of activation, as well as the ACRS-induced suppression of host resistance. ACRS and control mice also had equivalent activation of macrophages. With in vitro HKLM stimulation, splenocytes from ACRS-treated mice produced significantly higher levels of IFNgamma and slightly higher levels of IL-6 in comparison with the nonstressed mice, although equivalent levels of lymphocyte proliferation were obtained. Additionally, ACRS-treated mice showed comparable elevation of serum nitric oxide after infection, indicating macrophage bactericidal activity similar to nonstressed mice. Thus, it appears that ACRS inhibits host resistance through regulatory CD4+ T cells and/or effector cell functions downstream of CD4+ T cell activation, as well as through beta-ADR signaling, in that blockage of these receptors appears to aid host defenses by means other than elevation of helper T cell activity. Because CD4 T cell deficiency and beta-ADR blockage produced equivalent effects, beta-ADR+ CD4+ T cells may have a negative role on host defenses after ACRS.

Suppression of host resistance to Listeria monocytogenes by acute cold/restraint stress: lack of direct IL-6 involvement.

We conducted kinetic studies to evaluate the effects of acute cold/restraint stress (ACRS) on both primary and secondary host resistance to Listeria monocytogenes (LM). The involvement of IL-6 also was investigated using IL-6 knockout (KO) mice on the BALB/c background. ACRS dramatically increased the serum corticosterone levels, indicating that ACRS activated the hypothalamic-pituitary-adrenal (HPA) axis. ACRS significantly inhibited host resistance to LM during a primary but not a secondary LM infection. During the primary infection, ACRS caused a significant delay in clearance of LM, loss of body weight, reduced food/water intake, and elevated levels of pro-inflammatory cytokines (IL-6, IL-1beta, and TNFalpha) and IFNgamma. ACRS IL-6 KO mice showed higher LM burdens than did IL-6 KO controls, suggesting that IL-6 is not required for the ACRS-impairment of host resistance. Elevated levels of IL-1beta and TNFalpha may compensate for the absence of IL-6 and maintain the ACRS-induced impairment, in that the serum and splenic IL-1beta and TNFalpha levels were significantly higher in infected ACRS IL-6 KO mice, but not in control IL-6 KO mice, as compared to respective wild type controls. ACRS appears to inhibit IL-6 independent mechanisms associated with innate immunity and/or the development of adaptive immunity, but these reactions are unable to modulate the more efficient secondary immune responses.

Musical auditory hallucinosis from Listeria rhombencephalitis.

BACKGROUND: Complex auditory hallucinations have rarely been reported in cases of brainstem stroke or tumor. METHOD: Case study. RESULTS: A patient with acute Listeria rhombencephalitis complained of formed musical auditory hallucinations on the side of recent sensorineural deafness. MRI revealed an abscess in the middle cerebellar peduncule with extensive surrounding edema. CONCLUSIONS: Disruption of brainstem auditory pathways may cause complex auditory hallucinations. Potential pathogenetic mechanisms are discussed and a diagnostic approach is proposed.