The effect of the timing of exposure to Campylobacter jejuni on the gut microbiome and inflammatory responses of broiler chickens

Background Campylobacters are an unwelcome member of the poultry gut microbiota in terms of food safety. The objective of this study was to compare the microbiota, inflammatory responses, and zootechnical parameters of broiler chickens not exposed to Campylobacter jejuni with those exposed either early at 6 days old or at the age commercial broiler chicken flocks are frequently observed to become colonized at 20 days old. Results Birds infected with Campylobacter at 20 days became cecal colonized within 2 days of exposure, whereas birds infected at 6 days of age did not show complete colonization of the sample cohort until 9 days post-infection. All birds sampled thereafter were colonized until the end of the study at 35 days (mean 6.1 log10 CFU per g of cecal contents). The cecal microbiota of birds infected with Campylobacter were significantly different to age-matched non-infected controls at 2 days post-infection but generally the composition of the cecal microbiota were more affected by bird age as the time post infection increased. The effects of Campylobacter colonization on the cecal microbiota were associated with reductions in the relative abundance of OTUs within the taxonomic family Lactobacillaceae and the Clostridium cluster XIVa. Specific members of the Lachnospiraceae and Ruminococcaceae families exhibit transient shifts in microbial community populations dependent upon the age at which the birds become colonized by C. jejuni. Analysis of ileal and cecal chemokine/cytokine gene expression revealed increases in IL-6, IL-17A and Il-17F consistent with a Th17 response but the persistence of the response was dependent on the stage/time of C. jejuni colonization that coincide with significant reductions in the abundance of Clostridium cluster XIVa. Conclusions This study combines microbiome data, cytokine/chemokine gene expression with intestinal villus and crypt measurements to compare chickens colonized early or late in the rearing cycle to provide insights into the process and outcomes of Campylobacter colonization. Early colonization results in a transient growth rate reduction and pro-inflammatory response but persistent modification of the cecal microbiota. Late colonization produces pro-inflammatory responses with changes in the cecal microbiota that will endure in market ready chickens

NADPH oxidase-derived H2O2 subverts pathogen signaling by oxidative phosphotyrosine conversion to PB-DOPA

Strengthening the host immune system to fully exploit its potential as antimicrobial defense is vital in countering antibiotic resistance. Chemical compounds released during bidirectional host–pathogen cross-talk, which follows a sensing-response paradigm, can serve as protective mediators. A potent, diffusible messenger is hydrogen peroxide (H(2)O(2)), but its consequences on extracellular pathogens are unknown. Here we show that H(2)O(2), released by the host on pathogen contact, subverts the tyrosine signaling network of a number of bacteria accustomed to low-oxygen environments. This defense mechanism uses heme-containing bacterial enzymes with peroxidase-like activity to facilitate phosphotyrosine (p-Tyr) oxidation. An intrabacterial reaction converts p-Tyr to protein-bound dopa (PB-DOPA) via a tyrosinyl radical intermediate, thereby altering antioxidant defense and inactivating enzymes involved in polysaccharide biosynthesis and metabolism. Disruption of bacterial signaling by DOPA modification reveals an infection containment strategy that weakens bacterial fitness and could be a blueprint for antivirulence approaches

Relationship of Fear of Death and Level of Self-Esteem in College Students

Self-esteem and death anxiety instruments were administered to a total of 383 undergraduates; black and white, males and females were included in the sample. Consistent with previous data, higher scores on death anxiety were shown by female subjects. Black males displayed significantly higher self-esteem scores. An analysis of subgroups low and high in self-esteem produced support for a negative relationship between level of self-esteem and death anxiety. </jats:p

Socio-Economic, Academic, and Support Factors in Relation to the Academic Performance of on-Probation Students

In higher education, academic probation is a serious issue that often results from the complex interactions of several different causes. This quantitative research evaluates the social, academic, and support aspects related to students being placed on probation and their academic performance level. The study involved 69 undergraduate students through purposive sampling who were on academic probation at one of the institutions in Ozamiz City. The researchers used the descriptive-correlational research design, Family Affluence Scale Learning, Study Strategies Inventory, and the Social Support Questionnaire were instruments used in the study. Mean, standard deviation, frequency, Percentage, and Pearson Product-Moment Correlation Coefficient were the statistical tools used. The results indicate that work and academic responsibilities, classroom involvement, teaching effectiveness, and support factors have significantly impacted students on probation. These students consistently exhibit poor academic performance, with the greatest difficulties arising in General Education, followed by Major subjects, and then Professional Education. The connection between socioeconomic factors and academic performance was generally found to be insignificant. Additionally, there was no significant relationship between socioeconomic factors and support factors, nor between academic and support factors