Listeria monocytogenes is a pathogen of significant concern in many ready to eat foods due to its ability to survive and multiply even under significant environmental stresses. Listeriosis in humans is a concern, especially to high-risk populations such as those who are immunocompromised or pregnant, due to the high rates of morbidity and mortality. Whole genome sequencing has become a routine part of assessing L. monocytogenes isolated from patients, and the frequency of different genetic subtypes associated with listeriosis is now being reported. The recent abundance of genome sequences for L. monocytogenes has provided a wealth of information regarding the variation in core and accessory genomic elements. Newly described accessory genomic regions have been linked to greater virulence capabilities as well as greater resistance to environmental stressors such as sanitizers commonly used in food processing facilities. This review will provide a summary of our current understanding of stress response and virulence phenotypes of L. monocytogenes, within the context of the genetic diversity of the pathogen.

Untreated biological soil amendments of animal origin (BSAAO) are commonly used as biological fertilizers but can harbor foodborne pathogens like Salmonella enterica, leading to potential transfer from soils to fruits and vegetables intended for human consumption. Heat-treated poultry pellets (HTPP) can provide produce growers with a slow-release fertilizer with a minimized risk of pathogen contamination. Little is known about the impact of HTPP-amended soil on the survival of Salmonella enterica. The contributions of RpoS and formation of viable but nonculturable cells to Salmonella survival in soils are also inadequately understood. We quantified the survival of Salmonella enterica subsp. enterica serovar Newport wild-type (WT) and rpoS-deficient (ΔrpoS mutant) strains in HTPP-amended and unamended soil with or without spinach plants over 91 days using culture and quantitative PCR methods with propidium monoazide (PMA-qPCR). Simulated “splash” transfer of S. Newport from soil to spinach was evaluated at 35 and 63 days postinoculation (dpi). The S. Newport WT and ΔrpoS mutant reached the limit of detection, 1.0 log CFU/g (dry weight), in unamended soil after 35 days, whereas 2 to 4 log CFU/g (dry weight) was observed for both WT and ΔrpoS mutant strains at 91 dpi in HTPP-amended soil. S. Newport levels in soils determined by PMA-qPCR and plate count methods were similar (P > 0.05). HTPP-amended soils supported higher levels of S. Newport transfer to and survival on spinach leaves for longer periods of time than did unamended soils (P < 0.05). Salmonella Newport introduced to HTPP-amended soils survived for longer periods and was more likely to transfer to and persist on spinach plants than was S. Newport introduced to unamended soils. IMPORTANCE Heat-treated poultry pellets (HTPP) often are used by fruit and vegetable growers as a slow-release fertilizer. However, contamination of soil on farms may occur through contaminated irrigation water or scat from wild animals. Here, we show that the presence of HTPP in soil led to increased S. Newport survival in soil and to greater likelihood of its transfer to and survival on spinach plants. There were no significant differences in survival durations of WT and ΔrpoS mutant isolates of S. Newport. The statistically similar populations recovered by plate count and estimated by PMA-qPCR for both strains in the amended and unamended soils in this study indicate that all viable populations of S. Newport in soils were culturable.

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Electroacupuncture (EA) relieves visceral hypersensitivity (VH) with underlying inflammatory bowel diseases. However, the mechanism by which EA treats ileitis-induced VH is not clearly known. To assess the effects of EA on ileitis-induced VH and confirm whether EA attenuates VH through spinal PAR-2 activation and CGRP release, goats received an injection of 2,4,6-trinitro-benzenesulfonic-acid (TNBS) solution into the ileal wall. TNBS-injected goats were allocated into VH, Sham acupuncture (Sham-A) and EA groups, while goats treated with saline instead of TNBS solution were used as the control. Goats in EA group received EA at bilateral Hou-San-Li acupoints for 0.5 h at 7 days and thereafter repeated every 3 days for 6 times. Goats in the Sham-A group were inserted with needles for 0.5 h at the aforementioned acupoints without any hand manipulation and electric stimulation. Visceromotor responses to colorectal distension, an indicator of VH, were recorded by electromyography. The terminal ileum and thoracic spinal cord (T 11) were sampled for evaluating ileitis at days 7 and 22, and distribution and expression-levels of PAR-2, CGRP and c-Fos on day 22. TNBStreated-goats exhibited apparent transmural-ileitis on day 7, microscopically low-grade ileitis on day 22 and VH at days 7-22. Goats of Sham-A, VH or EA group showed higher (P < 0.01) VH at days 7-22 than the Control-goats. EA-treated goats exhibited lower (P < 0.01) VH as compared with Sham-A or VH group. Immunoreactive-cells and expression-levels of spinal PAR-2, CGRP and c-Fos in the EA group were greater (P < 0.01) than those in the Control group, but less (P < 0.01) than those in Sham-A and VH groups on day 22. Downregulation of spinal PAR-2 and CGRP levels by EA attenuates the ileitis and resultant VH. Inflammatory bowel diseases (IBDs) are chronic, immune-mediated and remittent-relapsing gastrointestinal inflammation. Crohn's disease (CD) and ulcerative colitis (UC) are the predominant clinical types of IBDs and their resultant symptoms include diarrhea, nausea, weight loss, abdominal pain and visceral hypersensitivity (VH) 1,2. There are two-thirds of IBD patients suffering from VH during their acute flares and remission 3,4. The persistent nature of VH impairs the patient's quality of life and consumes huge medical resources throughout the world. The environmental stress, inflammation and traumatic injuries trigger the development of VH. However, its underlying mechanism is not completely understood. A G-protein coupled receptor, PAR-2, is activated due to proteolytic cleavage of trypsin, tryptase and cathepsin-S 5-7. Over the years, studies have reported that the PAR-2 activation on resident mast cells, neutrophils or macrophages initiates for the release of inflammatory mediators, i.e., cytokines, chemokines and prostaglandins, which triggers the production of neurogenic mediators, i.e., substance-P (SP) and calcitonin gene-related peptide (CGRP) from the enteric neurons as well as afferent nerves to elicit eventually the VH 8-10. Cenac et al. 11 infu...

The total of thirteen different avocado (Persea americana Mill.) genotypes were collected for evaluating the fruit characteristics in the laboratory of Agricultural Research Station, Pakhribas during November 2017. The fully matured fruits from the farmer's field at Patle, Dhankuta were collected. The criteria for selecting the genotypes were fruit weight, fruit length, fruit diameter, seed weight, pulp weight, pulp to fruit ratio and the seed weight percentage. The result suggests the potentiality of the genotypes PAKAV002 and PAKAV010 in most of the evaluated characters as compared to the tested genotypes. The genotypes PAKAV008 and PAKAV007 were disliked as they have 32.59% and 28.39% of seed weight to the total fruit weight. The genotypes PAKAV002 and PAKAV010 had the average fruit weight ranging (307.1 g and 346.8 g), maximum of pulp to fruit ratio 62.34% and 56.97%. Similarly, genotypes PAKAV010 (11.425%), PAKAV013 (11.96%) and PAKAV002 (14.47%) had low seed weight to the total fruit weight which is regarded important factor for avocado selection and evaluation. This result shows that the genotypes PAKAV002 and PAKAV010 should be further evaluated for fruit characteristics and the quality.