Dietary supplementation with ferric tyrosine improves zootechnical performance and reduces caecal Campylobacter spp. load in broilers.

1. The objective of this study was to evaluate the effect of ferric tyrosine on the reduction of Campylobacter spp. and zootechnical performance in broilers exposed to Campylobacter spp. using a natural challenge model to simulate commercial conditions. Additionally, the minimum inhibitory concentrations (MICs) of ferric tyrosine against common enteropathogens were evaluated. 2. At the start of the trial, 840 healthy male 1-d-old birds (Ross 308) were randomly allocated to 6 replicate pens of 35 birds each and fed diets containing different concentrations of ferric tyrosine (0, 0.02, 0.05 and 0.2 g/kg) in mash form for 42 d. 3. Broilers fed diets containing ferric tyrosine showed significantly higher body weight at d 42 and weight gain compared to the control group. However, birds fed ferric tyrosine ate significantly more than the control birds so significant improvements in feed conversion rate were not observed. 4. Microbiological analyses of caecal samples collected on d 42 of the study showed, per gram of sample, 2-3 log10 reduction in Campylobacter spp. and 1 log10 reduction in Escherichia coli in the groups fed diets containing ferric tyrosine compared to the control. 5. The MICs of ferric tyrosine was >400 mg/l for C. jejuni and >200 mg/l for E. coli and Salmonella enterica, indicating that ferric tyrosine did not exert antimicrobial activity. 6. The results showed that birds fed ferric tyrosine grew faster and consumed more feed compared to the control group, indicating potential benefits of faster time to reach slaughter weight with no significant reduction on feed efficiency. Moreover, ferric tyrosine significantly reduced caecal Campylobacter spp. and E. coli indicating potential as a non-antibiotic feed additive to lower the risk of infections transmitted through the food chain.

TYPLEX® Chelate, a novel feed additive, inhibits Campylobacter jejuni biofilm formation and cecal colonization in broiler chickens.

Reducing Campylobacter spp. carriage in poultry is challenging, but essential to control this major cause of human bacterial gastroenteritis worldwide. Although much is known about the mechanisms and route of Campylobacter spp. colonization in poultry, the literature is scarce on antibiotic-free solutions to combat Campylobacter spp. colonization in poultry. In vitro and in vivo studies were conducted to investigate the role of TYPLEX® Chelate (ferric tyrosine), a novel feed additive, in inhibiting Campylobacter jejuni (C. jejuni) biofilm formation and reducing C. jejuni and Escherichia coli (E. coli) colonization in broiler chickens at market age. In an in vitro study, the inhibitory effect on C. jejuni biofilm formation using a plastic bead assay was investigated. The results demonstrated that TYPLEX® Chelate significantly reduces biofilm formation. In an in vivo study, 800 broilers (one d old) were randomly allocated to 4 dietary treatments in a randomized block design, each having 10 replicate pens with 20 birds per pen. At d 21, all birds were challenged with C. jejuni via seeded litter. At d 42, cecal samples were collected and tested for volatile fatty acid (VFA) concentrations and C. jejuni and E. coli counts. The results showed that TYPLEX® Chelate reduced the carriage of C. jejuni and E. coli in poultry by 2 and 1 log10 per gram cecal sample, respectively, and increased cecal VFA concentrations. These findings support TYPLEX® Chelate as a novel non-antibiotic feed additive that may help produce poultry with a lower public health risk of Campylobacteriosis.

A new method to visualize the Helicobacter pylori-associated Lewis(b)-binding adhesin utilizing SDS-digested freeze-fracture replica labeling.

Freeze-fracture replica labeling has become a versatile tool to visualize both membrane components and other cell structures using SDS-replica cleaning before specific immunogold labeling of proteins or lipids. We report here for the first time the adoption and optimization of the method to studies of bacterial envelopes, as applied to structural analysis of the distribution of the unique BabA-adhesin of the gastric pathogen Helicobacter pylori. BabA is important for bacterial adherence to the human epithelial cell lining of the stomach. The adhesin was found to be distributed all over the bacterial cell surfaces. Our results suggest that the SDS-replica labeling allows assessment of protein localization to distinct cell compartments and analysis of co-localization with neighboring membrane structures.

Age-related changes in antral endocrine cells in mice.

Antral endocrine cells in four age groups of mice, namely prepubertal (1 month old), young (3 months old), ageing (12 months old) and senescent (24 months old), were detected by immunocytochemistry and quantified by computerized image analysis. A statistical difference was detected between the different age groups regarding the numbers of gastrin-, somatostatin-, and serotonin-immunoreactive cells. The number of gastrin-immunoreactive cells significantly increased between 1 and 12 months, whereas they became significantly fewer between 12 and 24 months. Somatostatin-immunoreactive cell number increased significantly in 1-, 12- and 24-month-old mice, compared with young mice (3 months old). The number of serotonin-immunoreactive cells also increased significantly in 1- and 12-month-old mice as compared with young mice. There was a statistical difference between different age-groups regarding the cell secretory index (CSI) of somatostatin- and gastrin-immunoreactive cells, the CSI of both somatostatin- and serotonin-immunoreactive cells increased significantly in 1-, 12-, and 24-month-old mice, compared with young mice. There was no statistical difference between the different age-groups regarding the CSI of gastrin-immunoreactive cells, nor between males and females regarding the number and CSI of all the endocrine cell types investigated. It is suggested that the large number of somatostatin-immunoreactive cells in ageing and senescent mice might have an impact on the gastric delay seen in the elderly. It was concluded also that the changes in the antral endocrine cells could be involved in the development of dysfunction of the gastrointestinal tract inherent in ageing, or could be secondary to structural and functional changes in the alimentary tract caused by ageing.

Colonic endocrine cells in patients with carcinoma of the colon.

OBJECTIVE: To investigate the colonic endocrine cells in patients with colon carcinoma in order to establish a possible abnormality. PATIENTS: Twelve patients with colon adenocarcinoma (eight women and four men; mean age 69 years; range 52-88 years) were studied. As controls, macroscopically and histologically normal tissues from the colon of 12 patients (eight women and four men; mean age 66 years; range 34-86 years) were examined. These patients suffered from polyps, prolapsus, chronic diverticulitis, volvulus or haemorrhoids. METHODS: Macroscopically and histologically normal tissues from the colon of the patients, about 10 cm from the tumour, and of the controls were examined. Endocrine cells were immunostained with the avidin-biotin-complex method, and were quantified by computer image analysis using an automatic standard sequence analysis operation. Three parameters were used: (1) the number of endocrine cells per mm3 of epithelial cells; (2) the cell secretory index (CSI); and (3) the nuclear volume. RESULTS: The numbers of somatostatin- and serotonin-immunoreactive cells were significantly reduced in patients with colon carcinoma (P = 0.03 and 0.009, respectively). There was no difference between patients and controls regarding the numbers of PYY-, PP-, and enteroglucagon-immunoreactive cells. The CSI of somatostatin- and serotonin-immunoreactive cells were significantly decreased. There was no difference in the CSI between the patients and controls regarding PYY-, PP- or enteroglucagon-immunoreactive cells. The nuclear volumes of PYY- and enteroglucagon-immunoreactive cells increased significantly in the patients. The nuclear volume of PP-, somatostatin- and serotonin cells did not differ from those of the controls. CONCLUSION: The present results support the assumption that a disturbance in the colonic neuroendocrine system occurs in patients with colon carcinoma, which might affect the development of the tumour. The decrease in the number and CSI of somatostatin cells may account for the decrease of the colonic content of this peptide observed previously in these patients. The decrease in the number and CSI of serotonin-immunoreactive cells in patients with colon adenocarcinoma might be a method by which the body defends itself against this mitogenic substance.

Effect of ageing on colonic endocrine cell population in mouse.

BACKGROUND: Dysmotility in the gastrointestinal tract increases with age. Colonic endocrine cells play an important role in regulating intestinal secretion and motility. The objective was to study possible age-related changes in the colonic endocrine cells of an animal model. METHODS: The colonic endocrine cells in four different age groups of mice were investigated by immunocytochemistry and quantified by computerized image analysis. The ages of these groups were 1, 3, 12 and 24 months old. RESULTS: The numbers of peptide YY (PYY), enteroglucagon and serotonin immunoreactive (IR) cells in 1-month-old mice were significantly increased compared with those of 3-month-old mice. Similarly, the numbers of these cells were significantly greater in 12- and 24-month-old mice than in 3-month-old mice. The cell secretory index (CSI) of enteroglucagon and serotonin IR cells was higher in 1-, 12- and 24-month-old mice than in 3-month-old mice. There was no significant difference between the different age groups regarding the CSI of PYY IR cells, nor was there any statistical difference between females and males in all endocrine cell types regarding numbers and CSI. CONCLUSION: It is suggested that the increase in colonic endocrine cells prior to puberty might reflect the role of gut hormones in the development of the gastrointestinal tract. It is speculated further that the increase in colonic endocrine cells with ageing may compensate for increased receptor resistance and/or weakened response of effector organs. It is suggested that the increase in numbers and unchanged CSI of PYY cells with advancing age may be responsible for the slow colonic transit and constipation, both of which increase with age.

Image analysis of the duodenal endocrine cells in mice with particular regard to optical densitometry.

The endocrine cells in the murine proximal duodenum have been investigated by means of immunohistochemistry and computerized image analysis. Five endocrine cell types were identified, namely secretin-, gastric inhibitory polypeptide (GIP)-, gastrin-CCK-, somatostatin- and serotonin immunoreactive cells. The number of endocrine cells/mm3 epithelial cells was estimated and the cell secretory index (CSI) for different endocrine cell types was determined. Furthermore, the optical density of the cellular immunoreactivity and the immunoreactive area in the cell were determined and an index, cell immunoreactivity content was estimated as the optical density multiplied by the immunoreactive area. It has been suggested that the use of this index might better reflect the cellular peptide/amine content than does the CSI. Serotonin-immunoreactive cells were the predominant endocrine cell type, followed by gastrin/CCK-immunoreactive cells. The numbers of secretin-, GIP- and somatostatin immunoreactive cells were almost identical. All endocrine cell types were present both in crypts and in villi, but were, more numerous in the crypts, except for secretin which was more frequent in the villi.