Bacteria in heart and lungs of young chicks

AIMS: The purpose of these experiments was to determine whether the heart and lungs of young chicks harboured bacteria. METHODS AND RESULTS: Samples of the heart and lungs were aseptically removed from chicks on scheduled sampling days. Experiment 1 showed that of the 360 birds evaluated during the late embryonic and early post-hatching periods, only 10.8% harboured bacteria in the heart, lungs, and heart and lungs simultaneously. Experiment 2 suggested that bacteria in these organs were transient. Twenty-three bacterial species were found in the hearts whereas 30 were found in the lungs. Experiment 3 showed that only 1.4% of embryos harboured bacteria in the yolk, albumen, heart and lungs whereas 12.9% of the embryos had bacteria in the air cell. CONCLUSIONS: During the post-hatching period, there was a higher incidence of bacterial isolation in the heart and lungs, whilst during the embryonic development period, there was a lower incidence of bacterial isolation from these two organs. Results suggested that the heart and lungs do not have a residual bacterial flora; rather, opportunistic bacteria occasionally pass through these tissues. SIGNIFICANCE AND IMPACT OF THE STUDY: These experiments proved that bacteria could be isolated in the heart and lungs of healthy chicks reared from E17 to 3 weeks of age.     

Fe3+ transport by brush-border membrane vesicles isolated from normal and hypoxic mouse duodenum and ileum

Studies of 59Fe3+ uptake by brush-border membrane vesicles prepared from mouse duodenum have indicated that uptake represents transport across the brush-border membrane which is rate-limited by the membrane-transfer step (Simpson, R.J. and Peters, T.J. (1984) Biochim. Biophys. Acta 772, 220-226). Further studies presented here reveal that the uptake rate represents the net influx rate for Fe3+ and is independent of Na+ in the medium and of the method of vesicle preparation. Uptake by brush-border membrane vesicles prepared from mouse distal ileum also represents predominantly transport and is higher than that observed with duodenal brush-border membrane vesicles. Studies of the initial uptake rate by vesicles prepared from normal and hypoxic mouse intestine demonstrated an increase in Fe3+ transport in duodenal vesicles only.     

Distribution of 3-hydroxy-3-methylglutaryl-CoA reductase in isolated villus and crypt cells of chick duodenum, jejunum and ileum

3-Hydroxy-3-methylglutaryl-CoA reductase (EC 1.1.1.34), the major rate-limiting enzyme of cholesterogenesis, was studied in epithelial cells isolated in a villus to crypt gradient from chick duodenum, jejunum and ileum, in order to resolve the apparent controversy that exists on the anatomical localization of sterol synthesis in the intestine. Consistent separation was demonstrated by using the marker enzymes alkaline phosphatase, specific to the villus cells, and thymidine kinase, specific to the crypt cells. No relative difference in stability was observed, as shown by the equal distribution of acid phosphatase. Cells were 90-95 per cent viable. The highest specific activity of reductase was located in the microsomal fraction (41 per cent of the total). The mitochondria had lower specific activity (8 per cent of the total). The distribution of reductase activity in epithelial cells of the villus-crypt axis was also studied. The specific activity in each cell fraction from chick duodenum was clearly lower than that in jejunum and ileum. The jejunal and ileal crypt regions showed lower specific activity than the villus cells. About 70 per cent of total reductase activity was found in cells from the upper and the mid villus fraction in each intestinal segment.     

3-Hydroxy-3-methylglutaryl-CoA reductase, mevalonate-5-pyrophosphate decarboxylase and acyl-CoA: cholesterol acyl-transferase from mucosa scrapings and isolated enterocytes from chick duodenum, jejunum and ileum

3-Hydroxy-3-methylglutaryl-CoA reductase, mevalonate-5-pyrophosphate decarboxylase and acyl-CoA: cholesterol acyltransferase activities were assayed in mucosal scrapings and isolated enterocytes from chick duodenum, jejunum and ileum. Maximal reductase and decarboxylase specific activities were found in ileum and jejunum, while ileum exhibited the minimal acyltransferase specific activity. The isolated epithelial cells showed levels of reductase and acyltransferase specific activities higher than those found in mucosa scrapings, probably due to the contact of these microsomal proteins with proteolytic enzymes during homogenization of the mucosa. However, no protecting effect of the trypsin inhibitor (2mg/ml) could be observed on reductase activity in mucosa scrapings. The cytosolic location of decarboxylase may account for the similar levels of specific activities found in mucosa scrapings and isolated enterocytes.     

Influence of diet and monensin on development of anaerobic fungi in the rumen, duodenum, cecum, and feces of cows.

Three cows with fistulated rumens, duodenums, and ceca were fed five different diets: lucerne hay, lucerne hay plus whey (40:60), lucerne hay plus beets (50:50), corn silage plus monensin (40 ppm [40 g/kg] of dry matter intake), and lucerne hay plus monensin (80 ppm of dry matter intake). The fungal population was observed in the rumen, duodenum, cecum, and rectum and varied with diet; it was most abundant with lucerne hay alone and with corn silage plus monensin. The proportion of particles colonized by fungi in the duodenum, the cecum, and feces was measured by microscopic observation and varied from 5 to 50%, depending on the diet. The further sporangia attached to the plant particles were from the rumen, the more likely they were to be devoid of spores. Results confirmed the influence of diet on the development of the ruminal fungal population and showed that monensin does not eliminate these microorganisms. They also confirmed the presence of anaerobic fungi in the ruminant intestine. It is likely that anaerobic fungi leave the rumen attached to plant particles. However, large colonies of nonrhizoidal-type fungi were observed in cecum samples and in feces; at these sites, environmental conditions are perhaps more favorable for this type of fungus than they are in the rumen.     

Genomic diversity and relatedness of bifidobacteria isolated from a porcine cecum

This study initially involved the isolation of a number of bifidobacteria from either the lumen or the epithelium of a porcine cecum. A total of 160 isolates were selected at random on MRS plates containing cysteine hydrochloride (0.5 g/liter) and mupirocin (50 mg/liter). All were identified as bifidobacteria based on fructose-6-phosphate phosphoketolase activity. Following genomic digestion with the restriction enzyme XbaI and pulsed-field gel electrophoresis (PFGE), the isolates produced 15 distinct macro-restriction patterns. Several of the PFGE patterns differed by only 1, 2, or 3 DNA fragments and were grouped as related patterns into seven PFGE types, termed A through G. The related patterns appeared to show genomic plasticity within the isolates arising from chromosomal mutations or possibly horizontal transfer of plasmids. The relative frequency of each PFGE type was maintained within each cecal sample, with PFGE type E representing approximately 50% of the isolates. Randomly amplified polymorphic DNA PCR, cell morphology, whole-cell protein profiling, 16S ribosomal DNA sequencing, and DNA-DNA hybridization were used to determine if the seven apparently unrelated PFGE types represented genetically distinct isolates. Four groups were identified: PFGE types A, C/D/G, B/E, and F, and these appeared to represent Bifidobacterium minimum, Bifidobacterium pseudolongum subsp. pseudolongum, and Bifidobacterium pseudolongum subsp. globosum and two new species, respectively. The data demonstrate the presence of considerable genomic diversity within a relatively simple bifidobacteria population, consisting of 15 distinct strains representing four groups, which was maintained throughout the porcine cecal contents and epithelial layer.     

Extrinsic control of the release of galanin and VIP from intrinsic nerves of isolated, perfused, porcine ileum.

By immunohistochemistry galanin-like immunoreactivity and vasoactive intestinal polypeptide (VIP)-like immunoreactivity were found in nerve cell bodies mostly in the submucous plexus and in nerve fibres in the mucosa, submucosa and muscularis including the myenteric plexus of the porcine ileum and were found to co-exist in most of these structures. Using isolated, perfused porcine ileum we studied the release of galanin and VIP in response to electrical stimulation of the mixed periarterial nerves or to intraarterial infusions of different neuroactive agents. Nerve stimulation (4-10 Hz) inhibited the basal release of galanin and VIP from the ileum (to 69 +/- 6 and 62 +/- 6% of basal release). After infusion of the alpha-adrenergic blocker, phentolamine, (10(-6) M) electrical stimulation increased the release of both galanin and VIP (to 140 +/- 12 and 133 +/- 13% of basal output). This increase was abolished by atropine (10(-6) M) and by hexamethonium (3.10(-5) M). Infusion of norepinephrine (10(-6) M) inhibited, whereas acetylcholine (10(-6) M) stimulated the release of both peptides. The effect of the latter was abolished by atropine. The inhibitory effect of nerve stimulation was not influenced by atropine. Our results suggest that the galanin- and VIP-producing intrinsic neurons receive inhibitory signals by noradrenergic nerve fibers and stimulatory signals mediated by cholinergic nerves, possibly via a cholinergic interneuron.     

Bacteria divert resources from growth for magellanic penguin chicks

The influence of bacteria on the growth of their wild avian hosts is unknown. We tested experimentally whether administration of a wide‐spectrum antibiotic (cephalosporine) during early development of magellanic penguin (Spheniscus magellanicus) chicks had any effect on their growth rates in the wild. Chicks that were injected in two occasions with cephalosporine grew faster than control untreated chicks. The positive effect of medication on nestling growth disappeared after the treatment ceased, did not alter haematological indices indicative of health status, had no influence on chick survival until near independence and was related to a changed bacterial composition of the faecal microbiota of treated chicks when compared with that from control chicks. These results were similar to those obtained for poultry with antimicrobials promoting growth and chick nutrient assimilation rates. Gram‐positive bacilli in the diphtheroid genus Corynebacterium are likely candidates to cause decreased growth rates in magellanic penguin chicks.     

Transferrin in isolated cells from rat duodenum and jejunum

Mucosal transferrin was determined as transferrin-like immunoreactivity (TLIR) by means of a 2-site immunoradiometric assay (IRMA). Scraped-off mucosal tissue as well as isolated mucosal cells from the duodenum and jejunum of normal and iron-deficient rats before and after a washing procedure were examined. In iron-deficient rats there was about twice as much TLIR in scraped-off mucosal tissue as in the untreated animals. In the duodenum and jejunum of normal and iron-deficient rats, TLIR contents of the isolated cells in the magnitude of 320-510 ng/mg dry weight were found. Washing isolated cells three times in ice-cold Hank's solution resulted in a nearly tenfold decrease of TLIR content in all groups. In contrast the cells' RNA content remained unchanged.     

Genome sequence of Lactobacillus amylovorus GRL1118, isolated from pig ileum

Lactobacillus amylovorus is a common member of the beneficial microbiota present in the pig gastrointestinal tract. Here, we report the genome sequence of the surface layer (S-layer) protein-carrying and potentially probiotic strain L. amylovorus GRL1118, which was isolated from porcine ileum and which shows strong adherence to pig intestinal epithelial cells.     

Mechanism of the serotonin effect on motility of the duodenum,ileum, and jejunum in awake rabbits

I. v. administration of serotonin to alert rabbits produced a phasic change of contractile activity of duodenum, ileum, and jejunum including excitatory and inhibitory components. It is shown that stimulation of the small bowel motility is caused by serotonin activation of non-cholinergic excitatory mechanism with participation of effector cholinergic neurones. The initial suppression of the motility is caused by participation of nonadrenergic noncholinergic inhibitory mechanism, and the secondary inhibition of contractile activity of a small bowel with serotonin has an adrenergic nature.     

Digestion of mucin polysaccharides in vitro by bacteria isolated from the rabbit cecum

The chemical composition of mucin prepared from rabbit small intestines was compared with that of commercial pig gastric mucin. Changes in carbohydrate structure of both mucins after degradation by rabbit cecal bacteria were monitored with the periodic acid-Schiff's reaction (PAS), gas-liquid chromatography, and blood group serology. Out of 220 bacterial isolates from the rabbit cecal microflora, 37 were able to remove more than 25% of PAS-reactive mucin material from pig gastric mucin, which was more easily digested than the rabbit preparation.Bacteroides spp. were most active in mucin digestion, but nonmucinolytic cecal isolates could also use the oligosaccharides likely to be released by this activity.     

Influence of diet and monensin on development of anaerobic fungi in the rumen, duodenum, cecum, and feces of cows

Three cows with fistulated rumens, duodenums, and ceca were fed five different diets: lucerne hay, lucerne hay plus whey (40:60), lucerne hay plus beets (50:50), corn silage plus monensin (40 ppm [40 g/kg] of dry matter intake), and lucerne hay plus monensin (80 ppm of dry matter intake). The fungal population was observed in the rumen, duodenum, cecum, and rectum and varied with diet; it was most abundant with lucerne hay alone and with corn silage plus monensin. The proportion of particles colonized by fungi in the duodenum, the cecum, and feces was measured by microscopic observation and varied from 5 to 50%, depending on the diet. The further sporangia attached to the plant particles were from the rumen, the more likely they were to be devoid of spores. Results confirmed the influence of diet on the development of the ruminal fungal population and showed that monensin does not eliminate these microorganisms. They also confirmed the presence of anaerobic fungi in the ruminant intestine. It is likely that anaerobic fungi leave the rumen attached to plant particles. However, large colonies of nonrhizoidal-type fungi were observed in cecum samples and in feces; at these sites, environmental conditions are perhaps more favorable for this type of fungus than they are in the rumen.     

Preparation of microvillus membrane vesicles from the intestine of embryonic and young chicks

1. A procedure is described for the isolation of microvillus membranes from 19-day old embryonic, newly hatched, and 2-day old chicken intestine. 2. The magnesium concentration of epithelial cell homogenates is shown to be a crucial factor in obtaining membranes of equal purity from the three age groups. 3. Microvillus membranes are purified 20-25 fold over the original homogenate and form vesicles which are tightly sealed based on the Na+-dependent accumulation of glucose to levels four to five times equilibrium values. 4. These membrane preparations should prove useful in future studies concerning the embryonic and neonatal development of microvillus enzymes and nutrient transport systems in the chicken.     

Preparation and properties of isolated epithelial intestinal cells from chicken cecum and jejunum

The isolating agents, one enzymatic (hyaluronidase) and two chemical (sodium citrate and EDTA) have been used to search for the best technique to prepare suspensions of viable cells from chicken cecum and jejunum. Viability of enterocytes was assessed in terms of cell membrane integrity (trypan blue exclusion test), metabolic activity (oxygen uptake, lactate production and ATP content) and monosaccharide cumulative capacity. Results show that: In both cecum and jejunum, membrane integrity is better in cells harvested with citrate than those isolated with hyaluronidase or EDTA; The best metabolic status was found in cecal cells isolated with citrate and in jejunal cells obtained with hyaluronidase; The capacity to support alpha-methyl-D-glucoside gradients is highest in the cells harvested with citrate. The citrate-containing isolation medium is thus considered to yield epithelial cell suspensions with the best functional conditions.