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Biomedical subjects

C Schneitz

Publications and source records attributed to C Schneitz.

17 recordsLinked to original sources
PubMed1999

Efficacy of a commercial competitive exclusion product against Campylobacter jejuni.

1. Newly-hatched broiler chicks were treated orally with a commercial competitive exclusion product (Broilact) in 3 replicate trials 2. After 24 h the treated chicks and untreated control chicks were challenged orally with approximately 10(4) cfu of Campylobacter jejuni. 3. The caeca of the birds were examined quantitatively for campylobacter 12 d after the challenge. 4. In 3 separate trials, the treatment prevented or reduced colonisation of the challenge organisms in the caeca. The percentage of colonised birds varied from 0% to 62% in the treated groups and was 100% in the control groups. The average number of campylobacter was considerably lower in the treated groups than in the control groups.

Administration, Oral↗
PubMed1998

Comparison of two different types of competitive exclusion products.

The efficacy of two different types of commercial competitive exclusion (CE) products against Salmonella was studied in three chicken assay trials. Chicks were treated on the day of hatch and challenged one day later either with Salm. infantis (Trials 1 and 2) or a combination of Salm. infantis and Salm. enteritidis (Trial 3). The caeca of the birds were examined for Salmonella five days after challenge. The mean logarithmic counts of Salmonella were from 3.4 to 5.7 in the groups treated with product. A derived from the whole caecal contents of an adult bird, from 0.0 to 1.2 in the groups treated with product B, a highly selected product that does not contain any clostridia, and from 6.3 to 7.6 in the control groups. None of the challenge organisms superseded the other in Trial 3, and neither did the double challenge affect the protective capacity of the treatment materials.

Animals↗
PubMed1998

Effect of BROILACT on the physicochemical conditions and nutrient digestibility in the gastrointestinal tract of broilers.

The effect of the competitive exclusion (CE) product BROILACT on Salmonella colonization, nutrient digestibility, and the ME of the feed and the production of volatile fatty acids in the chicken gut was evaluated. The ileal viscosity and the fecal dry matter content were also determined. Newly hatched broiler chicks were given BROILACT orally either once on the day of hatch or five times during a period of 2 wk. Samples were taken at 12 and 31 d of age. In the beginning of the study and 2 wk later, chicks from each treatment group were taken to separate facilities to be challenged with Salmonella. Five and 4 d later, the chicks were killed and their intestines were examined for Salmonella. The results of the present study show that BROILACT protected the chicks against Salmonella, decreased the viscosity of the ileal contents, and increased the fecal dry matter content, and increased the ME value of the feed by 1.6% and the concentration of propionic acid in the cecal contents.

Animals↗
PubMed1996

Efficacy of a commercial competitive exclusion product against a chicken pathogenic Escherichia coli and E coli O157:H7.

The prevention of caecal colonisation of chicks by a poultry pathogenic Escherichia coli O20:K-:H8 and the human pathogenic E coli O157:H7 was studied in vivo in four one-week laboratory trials. Chicks were treated with a competitive exclusion product on the day of hatch and challenged one day later. The poultry pathogenic serotype showed higher levels of caecal colonisation than the human pathogenic serotype, but the protection against both pathogens was highly significant.

Animals↗
PubMed1993

Adhesion of Lactobacillus acidophilus to avian intestinal epithelial cells mediated by the crystalline bacterial cell surface layer (S-layer).

Lactobacillus acidophilus was isolated from washed and homogenized walls of the crop and caecum of an adult fowl. A strain that adhered well in the Fuller adhesion test was subcultured until colonies on Lactobacillus Selective agar changed from rough to smooth. This coincided with a change from aggregate to planktonic growth in liquid medium and a marked loss of ability to adhere. ultrastructure of cells from both types of culture was studied by electron microscopy. An S-layer formed the outermost part of the cell wall in the strongly-adherent strain, whereas this layer was covered with polymerized material or was absent in strains that lacked the ability to adhere, or those with reduced adherence.

Animals↗
PubMed1992

Efficacy of different microbial preparations for controlling Salmonella colonisation in chicks and turkey poults by competitive exclusion.

1. Control by competitive exclusion of intestinal colonisation by Salmonella infantis was studied in domestic chicks and turkey poults given a commercial product developed for use with chickens, compared with two similar preparations containing intestinal microorganisms from turkeys. 2. Each type of material protected both avian species when given orally before challenge; the degree of protection depended at least as much on the type of preparation as its host origin.

Animals↗
PubMed1992

Use of competitive exclusion to protect newly-hatched chicks against intestinal colonisation and invasion by Salmonella enteritidis PT4.

1. The recommended dose of a commercial competitive exclusion (CE) product (BROILACT) was given orally to newly-hatched broiler chicks to protect them against oral challenge by Salmonella enteritidis PT4. 2. In 5 replicate trials, half of the birds thus treated and half from untreated control groups were examined for salmonellas at 5 d and the other half at 12 d after challenge. 3. Caecal contents were examined quantitatively while heart, liver and spleen samples were examined qualitatively by enrichment. 4. The treatment effectively prevented both colonisation of the caeca and invasion of the other organs by S. enteritidis PT4; the average number of salmonellas was less than 10 colony forming units (cfu)/g of caecal contents in the treated birds and more than 10 million cfu/g in the untreated birds. 5. Infection of organs other than the caeca was completely prevented by protective treatment, whereas 38% of the untreated birds were still infected at the end of the trial.

Animal Husbandry↗
PubMed1992

Research note: automated droplet application of a competitive exclusion preparation.

An automatic dosing cabinet similar to that used for infectious bronchitis vaccination was used to treat newly hatched chicks with a commercial competitive exclusion product, BROILACT. Randomly selected boxes of treated and untreated (control) chicks were taken to the laboratory and challenged with either Salmonella infantis or Salmonella enteritidis (PT4) using the seeder bird technique. Three experiments were carried out with each serotype. Twelve days after challenge, the ceca of the chicks and, in one experiment, also pooled samples of other organs were examined for Salmonella. Automatic droplet application of BROILACT protected the chicks effectively in all six trials. The average number of Salmonella was about 10 cfu/g of cecal contents in the treated groups and 1,000,000 cfu/g in control groups. The pooled organ samples were found to be free from Salmonella in the treated groups whereas virtually all organs from the control groups tested positive for Salmonella.

Animals↗
PubMed1992

Factors affecting the incidence of necrotic enteritis, caecal carriage of Clostridium perfringens and bird performance in broiler chicks.

Two trials were conducted to study the effects of a competitive exclusion (CE) product BROILACT and the anticoccidial narasin on the incidence of necrotic enteritis (NE), the numbers of Clostridium perfringens (CP) in the caeca of broiler chicks and the performance of the birds. In trial 1 the effects of type of protein and partial replacement of a narasin containing diet with whole wheat were also studied. All groups of chicks were studied up to the point of slaughter at 43 days of age and after evisceration in a processing plant to determine slaughter yield. In trial 1, statistically significant results included the following: CE-treatment reduced total mortality, and incidence of NE, on diet containing animal but not vegetable protein. Caecal carriage of CP was also reduced, while slaughter yield increased. Narasin reduced caecal carriage of CP and increased both growth rate and slaughter yield in both trials. Whole wheat replacement improved feed conversion but reduced bird growth rate. In trial 2, both CE-treatment and narasin influenced feed intake, CE-treatment significantly only at days 22 and 44. Narasin improved feed conversion until 5 weeks of age and CE-treatment did so until 22 days of age. In both trials, there was also an interaction effect indicating that CE-treatment increased slaughter yield for birds that were not fed narasin.

Animal Feed↗
PubMed1991

Pilot-scale testing of the competitive exclusion method in chickens.

1. The efficacy of a commercial competitive exclusion (CE) product, BROILACT, was tested in pilot-scale trials involving groups of 100 broiler chicks. 2. Each group was challenged with Salmonella infantis through contact with infected seeder birds and numbers of salmonellae in the caecal contents were determined weekly. 3. The performance of the birds was also monitored over a 5-week period. 4. The results showed a gradual decline of the infection, even in the untreated groups, and a dose-dependent response to treatment. 5. The treatment had no significant effect on the performance of the birds.

Animals↗
PubMed1981

The anaerobically cultured cecal flora of adult fowls that protects chickens from Salmonella infections.

In this work we have analyzed the bacterial composition of anaerobically cultured cecal contents (mixed broth culture) of adult fowls previously shown able to protect 1 day old chickens from oral Salmonella infections. All four cultures studied in this paper gave complete protection against Salmonella infantis when used undiluted or in the 10(-2) dilution and at least some protection in the 10(-4) dilution. The total aerobic as well as anaerobic counts on the nonselective medium used (VLMH) were of the order of 10(8) viable organisms/ml indicating that the mixed broth culture consisted predominantly of facultative organisms. From a total of 239 colonies isolated on the basis of colony morphology 66 were obligate anaerobes and 173 facultative anaerobic or microaerophilic species. Isolates were selected from each medium. They were grouped and tentatively classified on the basis of their ability to grow on selective media, their colony and cell morphology. Gram stain and products formed from glucose fermentation (obligate anaerobes). Further characterization was performed using conventional carbohydrate fermentation and biochemical tests. However only a minor fraction of the anaerobic isolates could be identified as being identical to known species. The most numerous species were E. coli and various Lactobacilli which were still found in the highest dilution (10(-8)) of the broths. Fecal streptococci were the next most frequent, isolated at the 10(-7) dilution. The obligate anaerobes isolated included Gram-positive cocci and Gram-positive and -negative rods tentatively classified as Eubacteria, Propionibacteria, Clostridia, Fusobacteria and Bacteroides. A large number of them were isolated from the 10(-6) dilution and some species of Eubacteria and Clostridia could only be recovered from the 10(-3) or 10(-4) dilutions.

Anaerobiosis↗
PubMed1980

Combined therapy of Salmonella infection in chickens by antimicrobial agents followed by cultured cecal bacteria.

Week-old chickens infected with Salmonella infantis when one day old were treated with antimicrobial drugs either given alone or followed by peroral inoculation of bacterial culture. The bacteria were derived from the cecal contents of adult chickens. The antimicrobial drugs used were: neomycin, neomycin plus oxytetracycline, neomycin plus polymyxin, and sulfadiazine plus trimethoprim. The combined therapy with oxytetracycline plus neomycin and bacterial culture seemed to be the most effective, although the efficacy varied between the parallel trials. Sulfadiazine plus trimethoprim followed by treatment with the bacterial culture decreased the infection rate. The bacterial culture alone also had a slight anti-salmonella effect. When only antimicrobials were given, salmonellae rapidly reappeared in the intestines when the therapy was stopped.

Animals↗
PubMedDate not supplied

The competitive exclusion concept: development and future.

The origin of the competitive exclusion (CE) concept in controlling a Salmonella infantis outbreak in poultry in 1971 and the subsequent development of a commercial treatment product are described. The possible role of CE in salmonella control, current status of the concept and theories relating to the bacteria involved and mechanisms of protection are reviewed. Some observations are made on the need for methodological development and possibilities for extending the scope of CE to other pathogens and types of domestic animal.

Animals↗
PubMedDate not supplied

Competitive exclusion in the young bird: challenge models, administration and reciprocal protection.

The competitive exclusion (CE) concept has been tested against both non-invasive and invasive salmonella serotypes. Studies with different challenge models indicate that CE treatment is likely to protect the young bird against all serotypes that are capable of intestinal colonization. Spray or 'droplet' application of the CE-treatment material was compared with administration in the first drinking water. Both methods gave a similar degree of protection against Salmonella infantis. A study was made to compare protection of newly hatched chicks and turkey poults by the one commercial CE product Broilact, and two similar preparations involving intestinal microorganisms from an adult turkey. Each preparation protected both avian species when administered orally prior to challenge, but the degree of protection obtained varied with the type of preparation and its host origin.

Animals↗
PubMedDate not supplied

Effect of a commerical competitive exclusion product on the colonization of Salmonella infantis in day-old pheasant chicks.

One-day-of-age pheasant chicks were treated orally with the competitive exclusion product Broilact in three replicate trials. The following day the treated chicks and untreated control chicks were challenged likewise with approximately 10(3) colony-forming units (cfu) of Salmonella infantis. Five days after challenge the cecal contents of the birds were examined quantitatively and by enrichment for S. infantis. In all three trials Broilact effectively reduced colonization of the challenge organism, the mean infection factor (IF) value (the logarithmic number of colony forming units of salmonella organisms per gram of cecal contents) for the treated groups being 2.9 and that for the salmonella control groups 8.4. Mortality during the 1 week rearing period was 5.0% in the Broilact treated groups and 8.5% in the salmonella control groups.

Animals↗
PubMedDate not supplied

Reduced incidence of Clostridium perfringens-associated lesions and improved performance in broiler chickens treated with normal intestinal bacteria from adult fowl.

The dosing of young chicks with cultures of normal gut flora has been termed "competitive exclusion" (CE). This study was undertaken to examine, under field conditions, the effect of CE treatment on counts of intestinal Clostridium perfringens (CP) and on the occurrence of CP-associated disease in broiler chickens. A farm having recurrent CP-associated health problems was selected as study site. The study comprised four broiler houses, with one treated and one untreated flock per house. Treated birds were sprayed with the CE product Broilact upon arrival at the farm. All flocks were offered feed containing the ionophorous anticoccidial agent narasin. The feed did not contain growth promoters. Treatment was associated with positive but statistically nonsignificant effects on gut health. Delayed intestinal proliferation of CP and delayed appearance of CP-associated gut lesions were found in CE-treated flocks. This delay was associated with improved production performance at slaughter.

Animal Feed↗