oxytetracycline--anhydrous and Poultry-Diseases

Staphylococcus aureus is an important human and veterinary pathogen that causes economic loss in the poultry industry. This study aimed to compare therapeutic efficacy of 4 commonly used antibiotics in poultry on S. aureus-induced arthritis in broilers. Sixty broilers, 8 weeks of age, were assigned at random into 7 groups as follows: (1) negative control (n = 5); (2) vehicle control (n = 5); (3) sulfadiazine-trimethoprim, 250 ml/1000 l drinking water (n = 10); (4) oxytetracycline 20%, 1 mg/l drinking water (n = 10); (5) florfenicol 10%, 1/1000 v/v in drinking water (n = 10); (6) enrofloxacin 10%, 1/1000 v/v in drinking water (n = 10) and (7) positive control (n = 10). Birds in group 2 were injected with 1 ml of sterile TSB medium into the right tibiotarsal joint on d 0 while other birds (except group 1) were challenged with 1 ml of 1.2 × 10(10) CFU/ml suspension of S. aureus bacteria. Antibiotic therapy was started from d 4 post challenge and continued for 5 d. At the end, birds were weighed and clinical severity of arthritis was determined. After blood collection, birds were slaughtered and tibiotarsal and hip joints were evaluated grossly. The content of inflammatory exudates of tibiotarsal joint and the degree of femoral head necrosis were recorded. Mucin clot test and histopathological evaluation were performed on right tibiotarsal joint. Serum interleukin 6 was also assayed. Sulfadiazine-trimethoprim had higher therapeutic efficiency with regard to most of the assayed criteria, whereas none of the antibiotics significantly affected femoral head necrosis and body weight. These data will help clinicians to have better antibiotic choice in field conditions.

Topics: Animals; Anti-Bacterial Agents; Arthritis; Chickens; Drug Combinations; Enrofloxacin; Female; Fluoroquinolones; Male; Oxytetracycline; Poultry Diseases; Staphylococcal Infections; Staphylococcus aureus; Sulfadiazine; Thiamphenicol; Treatment Outcome; Trimethoprim

Contamination of feeds with mycotoxins is a worldwide problem and mycotoxin-detoxifying agents are used to decrease their negative effect. The European Food Safety Authority recently stated guidelines and end-points for the efficacy testing of detoxifiers. Our study revealed that plasma concentrations of deoxynivalenol and deepoxy-deoxynivalenol were too low to assess efficacy of 2 commercially available mycotoxin-detoxifying agents against deoxynivalenol after 3 wk of continuous feeding of this mycotoxin at concentrations of 2.44±0.70 mg/kg of feed and 7.54±2.20 mg/kg of feed in broilers. This correlates with the poor absorption of deoxynivalenol in poultry. A safety study with 2 commercially available detoxifying agents and veterinary drugs showed innovative results with regard to the pharmacokinetics of 2 antibiotics after oral dosing in the drinking water. The plasma and kidney tissue concentrations of oxytetracycline were significantly higher in broilers receiving a biotransforming agent in the feed compared with control birds. For amoxicillin, the plasma concentrations were significantly higher for broilers receiving an adsorbing agent in comparison to birds receiving the biotransforming agent, but not to the control group. Mycotoxin-detoxifying agents can thus interact with the oral bioavailability of antibiotics depending on the antibiotic and detoxifying agent, with possible adverse effects on the health of animals and humans.

Topics: Amoxicillin; Animals; Anti-Bacterial Agents; Bile; Body Weight; Chickens; Eating; Europe; Female; Male; Oxytetracycline; Poultry Diseases; Trichothecenes

Topics: Animals; Anti-Bacterial Agents; Anti-Infective Agents; Lincomycin; Microbial Sensitivity Tests; Mycoplasma Infections; Mycoplasma iowae; Oxytetracycline; Poultry Diseases; Spectinomycin

To determine the prevalence of indicator bacteria resistant to antimicrobials among poultry in three Southeast Asian countries (Vietnam, Indonesia and Thailand), we examined the antimicrobial susceptibilities of commensal bacteria isolated from chickens. In total, 125, 117 and 180 isolates of Escherichia coli, Enterococcus faecalis and Enterococcus faecium, respectively, were used to test for antimicrobial susceptibility. Bacterial resistance to antimicrobial treatment was most frequently observed with oxytetracycline with a prevalence of 73.6% (E. coli), 69.2% (E. faecalis) and 92.2% (E. faecium). Resistance to fluoroquinolones, which are critically important medicines, was also frequently observed in E. coli (48.8%), E. faecalis (17.9%) and E. faecium (82.8%). The prevalence of indicator bacteria resistant to most of the antimicrobials tested in these countries was higher than those for developed countries. The factors underlying antimicrobial resistance may include inappropriate and/or excessive use of antimicrobials. These results highlight the need for monitoring the emergence and prevalence of antimicrobial resistance in developing countries.

Topics: Animals; Asia, Southeastern; Chickens; Drug Resistance, Microbial; Enterococcus faecalis; Enterococcus faecium; Epidemiological Monitoring; Escherichia coli; Fluoroquinolones; Gram-Positive Bacterial Infections; Oxytetracycline; Poultry Diseases; Prevalence; Species Specificity

Antimicrobials administered to laying hens may be distributed into egg white or yolk, indicating the importance of evaluating withdrawal times (WDTs) of the pharmaceutical formulations. In the present study, oxytetracycline and tylosin's WDTs were estimated. The concentration and depletion of these molecules in eggs were linked to their pharmacokinetic and physicochemical properties. Twenty-seven Leghorn hens were used: 12 treated with oxytetracycline, 12 treated with tylosin, and 3 remained as an untreated control group. After completion of therapies, eggs were collected daily and drug concentrations in egg white and yolk were assessed. The yolk was used as the target tissue to evaluate the WDT; the results were 9 and 3 days for oxytetracycline and tylosin, respectively. In particular, oxytetracycline has a good oral bioavailability, a moderate apparent volume of distribution, a molecular weight of 460 g/mol, and is lightly liposoluble. Tylosin, a hydrosoluble compound, with a molecular weight of 916 g/mol, has a low oral bioavailability and a low apparent volume of distribution, too. Present results suggest that the WDTs of the studied antimicrobials are strongly influenced by their oral bioavailability, the distribution, and the molecular weight and solubility, and that these properties also influence the distribution between the egg yolk and white.

Topics: Administration, Oral; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Chickens; Drug Residues; Eggs; Female; Oviparity; Oxytetracycline; Poultry Diseases; Time Factors; Tylosin

An experiment was performed to compare the microbiological efficacy of four treatments (oxytetracycline, trimethoprim-sulphonamide, amoxicillin (AMX) or enrofloxacin (ENR)) to control experimental colibacillosis induced by an avian pathogenic Escherichia coli (APEC) with reduced susceptibility to fluoroquinolones. The protocol was also developed in order to study resistance gene transfer. Broilers were first orally inoculated with multiresistant E. coli bearing plasmid genes conferring resistance to fluoroquinolones (qnr), cephalosporins (blaCTX-M or blaFOX), tetracycline or trimethoprim-sulphonamide. They were then inoculated in their air sacs with the APEC and treated as soon as symptoms appeared. Internal organs from dead or sacrificed birds were cultivated on non-supplemented or supplemented media. The inoculated O78 APEC was recovered significantly less frequently in ENR treated group (26%) compared to untreated group (47%). This was not true for other treated groups. Isolates obtained on non-supplemented media had the same susceptibility profile as the inoculated APEC. However, one isolate from the AMX-treated group obtained on AMX-supplemented media was resistant to AMX only, and one isolate from the same group obtained on ENR-supplemented media, showed a resistance profile suggesting acquisition of one of the multiresistance plasmids present in the intestinal microbiota. Molecular analysis performed on this multiresistant isolate confirmed the presence of a conjugative plasmid with qnr and blaCTX-M resistance genes. Thus, the experiment illustrated the emergence of resistant isolates in internal organs, probably via acquisition of a plasmid from the intestinal microbiota.

Topics: Amoxicillin; Animals; Anti-Bacterial Agents; Chickens; Drug Resistance, Bacterial; Drug Therapy, Combination; Enrofloxacin; Escherichia coli; Escherichia coli Infections; Fluoroquinolones; Oxytetracycline; Poultry Diseases

In the combat against bacterial resistance, there is a clear need to check the use of antibiotics in animal husbandry, including poultry breeding. The use of chicken feathers as a tool for the detection of use of antibiotics was investigated. An extraction method for the analysis of oxytetracycline (OTC) from feathers was developed and was tested by using incurred feathers obtained from a controlled animal treatment study. The use of McIlvain-ethylenediaminetetraacetic acid buffer only in combination with acetone gave the highest extraction yield, indicating the need of an organic solvent for feather extraction. By using the developed method, it was found that after a withdrawal time, the OTC concentration in feathers is in the mg kg⁻¹ range, far higher than that in muscle and liver tissue. Based on the analysis of individual segments of feathers from OTC-treated chicken, evidence was found supporting the hypothesis of secretion of antibiotics through the uropygial gland and external spread over feathers by grooming behaviour. It was also found that part of the administered OTC is built into the feather rachis. Finally, we provide the first evidence that the analysis of individual segments of the rachis can be used as a tool to discriminate among different treatment strategies, for example, therapeutic versus subtherapeutic. As a result, we concluded that the analysis of feathers is an extremely valuable tool in residue analysis of antibiotics.

Topics: Administration, Oral; Analytic Sample Preparation Methods; Animals; Animals, Inbred Strains; Anti-Bacterial Agents; Antibiotic Prophylaxis; Chickens; Dose-Response Relationship, Drug; Feathers; Liver; Muscles; Netherlands; Oxytetracycline; Poultry Diseases; Random Allocation; Substance Abuse Detection; Tissue Distribution

Development of antibiotic resistance in the microbiota of farm animals and spread of antibiotic-resistant bacteria in the agricultural sector not only threaten veterinary use of antibiotics, but jeopardize human health care as well. The effects of exposure to antibiotics on spread and development of antibiotic resistance in Escherichia coli from the chicken gut were studied. Groups of 15 pullets each were exposed under strictly controlled conditions to a 2-day course of amoxicillin, oxytetracycline, or enrofloxacin, added to the drinking water either at full therapeutic dose, 75% of that, or at the carry-over level of 2.5%. During treatment and for 12 days afterwards, the minimal inhibitory concentration (MIC) for the applied antibiotics of E. coli strains isolated from cloacal swabs was measured. The full therapeutic dose yielded the highest percentage of resistant strains during and immediately after exposure. After 12 days without antibiotics, only strains from chickens that were given amoxicillin were significantly more often resistant than the untreated control. Strains isolated from pullets exposed to carry-over concentrations were only for a few days more often resistant than those from the control. These results suggest that, if chickens must be treated with antibiotics, a short intensive therapy is preferable. Even short-term exposure to carry-over levels of antibiotics can be a risk for public health, as also under those circumstances some selection for resistance takes place.

Topics: Amoxicillin; Animals; Anti-Bacterial Agents; Chickens; Drug Resistance, Multiple, Bacterial; Enrofloxacin; Escherichia coli; Female; Fluoroquinolones; Gastrointestinal Tract; Humans; Male; Microbial Sensitivity Tests; Netherlands; Oxytetracycline; Poultry Diseases; Public Health; Specific Pathogen-Free Organisms; Time Factors

This study determined the prevalence and antimicrobial susceptibility of Salmonella isolated from broiler flocks in Japan. Caecal dropping samples were collected from 288 broiler flocks between November 2007 and February 2010. Salmonella was prevalent in 248 (86·1%) broiler flocks. The top three serovars were S. Infantis, S. Manhattan and S. Schwarzengrund. S. Infantis was found in all regions tested in this study. However, S. Manhattan and S. Schwarzengrund were frequently found only in the western part of Japan. High antimicrobial resistance rates were observed against oxytetracycline (90·2%), dihydrostreptomycin (86·7%) and ampicillin (36·5%), and 258 (90·5%) of 285 isolates were resistant to two or more antimicrobial agents. Interestingly, 26·3% of isolates were resistant to ceftiofur, especially 38·1% of S. Infantis isolates, although its use in broilers has not been approved in Japan. This study showed that Salmonella is highly prevalent (86·1%) in Japanese broiler flocks, that 90·5% of Salmonella isolates were multidrug-resistant, and that S. Infantis frequently exhibited resistance to cephalosporin antimicrobial agents.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Cephalosporins; Chickens; Dihydrostreptomycin Sulfate; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Feces; Japan; Microbial Sensitivity Tests; Oxytetracycline; Poultry Diseases; Salmonella enterica; Salmonella Infections, Animal

The clinical and microbial efficacy of antimicrobial treatments of avian colibacillosis was studied, using an experimental model on chickens previously inoculated with multiresistant commensal Escherichia coli strains. One E. coli with pMG252 plasmid containing bla(FOX5) and qnrA1 genes and another E. coli with pMG298 plasmid containing bla(CTX-M15) and qnrB1 genes were first orally inoculated to chickens Both isolates were also resistant to chloramphenicol, sulphamethoxazole, trimethoprim, streptomycin, gentamicin, kanamycin, and tetracycline. The birds were then experimentally infected with an avian pathogenic E. coli (APEC), via the air sac. Treatments (oxytetracycline (OTC), trimethoprim-sulfadimethoxin (SXT), amoxicillin (AMX) or enrofloxacin (ENR) were then offered at the therapeutic doses. Symptoms, lesions in dead or sacrificed birds, and isolation and characterization of APEC from internal organs were studied. Results showed that OTC, SXT or ENR treatments could control the pathology. AMX worsened the disease, possibly due to endotoxin shock. All APEC re-isolated from internal organs showed the same antimicrobial susceptibility as the APEC inoculated strain, except for one APEC isolate from an infected OTC-treated bird, which acquired tetracycline resistance only, and one APEC isolate recovered from the air sacs of a chicken in the infected SXT-treated group, which acquired the pMG252 plasmid and became multi-resistant. Thus three antimicrobials could control the disease but the experimental model enabled, to our knowledge, the first observation of plasmid transfer from a bacterium of the intestinal tract to a pathogenic isolate from the respiratory tract.

Topics: Amoxicillin; Animals; Anti-Bacterial Agents; Chickens; Drug Resistance, Bacterial; Enrofloxacin; Escherichia coli; Escherichia coli Infections; Female; Fluoroquinolones; Male; Oxytetracycline; Plasmids; Poultry Diseases; Sulfadimethoxine; Trimethoprim

To investigate the effects of rearing practices of commercial broiler chickens on the incidence of antimicrobial resistance in commensal Escherichia coli isolates, fecal E. coli isolates obtained in 4 farms were screened for anitimicrobial resistance. Ten E. coli isolates were recovered from each of the fecal samples collected from 10 birds in the farms at the ages of 2 days, 14-17 days, and 47-50 days. In 2 out of the 4 farms, no antimicrobials were used during the rearing period. In the other two farms, following collection of the fecal samples at 14 and 15 days of age, oxytetracycline (OTC), sulfadimethoxine (SDMX), and tylosin were given to birds on one farm and SDMX was used in the other. Isolates resistant to ampicillin and OTC that were obtained from an untreated flock at different sampling times were closely related to each other by pulsed-field gel electrophoresis patterns (PFGE) of XbaI-digested chromosomal DNA. PFGE analysis together with in vitro conjugation experiments suggested that diversity of resistance phenotypes within a clone may be resulted from the acquisition and loss of R-plasmids in an untreated and a treated flock. The numbers of resistance phenotypes observed among fecal isolates increased during the growth of the chickens in all the farms. The results in the present study suggest that persistence of commensal E. coli strains resistant to antimicrobials even in the absence of antimicrobial administration. It is also hypothesized that horizontal transmission of resistance determinants resulted in the emergence of different resistance phenotypes in those farms.

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Chickens; DNA, Bacterial; Drug Resistance, Multiple, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Feces; Microbial Sensitivity Tests; Oxytetracycline; Plasmids; Poultry Diseases; Sulfadimethoxine; Tylosin

We investigated for dynamics of Campylobacter clones on 2 different managerial broiler farms. Campylobacter isolates were differentiated by resistance typing and molecular typing methods. On farm I, the same C. jejuni clones resistant to fluoroquinolone and oxytetracycline were isolated after one and half years again and another susceptible clone was invaded. The susceptible clone was isolated again after half year. Broiler flocks on the farm may be repeatedly infected with a few C. jejuni clones. On farm II, new clones including antimicrobial resistant one, were often invaded. The change of predominant C. jejuni clone in each flock on both the farms was observed, in the absence of antimicrobial selective pressure.

Topics: Animals; Anti-Bacterial Agents; Campylobacter Infections; Campylobacter jejuni; Chickens; Colony Count, Microbial; Drug Resistance, Bacterial; Drug Resistance, Multiple, Bacterial; Fluoroquinolones; Japan; Microbial Sensitivity Tests; Oxytetracycline; Poultry Diseases

The purpose of the present study was to compare the ability of enrofloxacin, oxytetracycline, and sulfadimethoxine to reduce morbidity and mortality caused by Escherichia coli (colibacillosis) in broiler chickens. The chickens were raised in 80 pens (20 birds per pen) with 20 pens representing each treatment group under simulated commercial conditions that produced a colibacillosis challenge scenario. Each group of 20 randomized pens (replicates) was given one of four water treatments. Chickens that received enrofloxacin had significantly less mortality (P < 0.01), lower average gross pathology (colibacillosis) scores (P < 0.01), and better feed-conversion ratios (P < 0.05) than did chickens that received either oxytetracycline or no medication. Chickens that received enrofloxacin had significantly less mortality and lower pathology scores than those that received sulfadimethoxine and numerically lower feed conversion than the sulfadimethoxine group. Results from the present study show that enrofloxacin is superior to oxytetracycline and sulfadimethoxine for the control of morbidity and mortality caused by E. coli in broiler chickens. Our findings will help veterinarians choose and prescribe the most efficacious antimicrobial when treating colibacillosis.

Topics: Air Sacs; Analysis of Variance; Animals; Anti-Bacterial Agents; Body Weight; Chickens; Enrofloxacin; Escherichia coli Infections; Fluoroquinolones; Oxytetracycline; Poultry Diseases; Quinolones; Sulfadimethoxine; Treatment Outcome

A Mycoplasma synoviae (MS)-free flock of broiler breeders was housed for brooding and rearing on an MS endemic farm. PCR revealed that the flock became infected within nine weeks. At 22 weeks the flock was transferred to a clean and disinfected house on a previously depopulated farm. The birds were then subjected to three treatments with fluoroquinolones due to recurrent Escherichia coli peritonitis and from the 32 weeks of age they received 600 ppm of oxytetracycline hydrochloride continuously in the feed. Monitoring by PCR showed a decrease in MS positive birds after 34 weeks of age and MS may have been eradicated as judged by consistent negative results in PCR. We conclude that intensive antibiotic treatments supported by adequate biosecurity could clear MS from infected broiler breeders.

Topics: Animal Husbandry; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Brazil; Chickens; Disease Outbreaks; Escherichia coli Infections; Female; Fluoroquinolones; Hygiene; Male; Mycoplasma; Mycoplasma Infections; Oxytetracycline; Peritonitis; Polymerase Chain Reaction; Poultry Diseases

This study describes the influence of bioptivet GB on minimum inhibitory concentrations (MIC) for oxytetracycline (OTC) of the intestinal E. coli flora of young broiler chickens after oral administration at a dosage equivalent to a prophylactic course of treatment. From day 6 until day 15 one group of 50 birds received a diet containing 124 ppm OTC, another group of 75 birds served as non medicated control. Investigated E. coli had been isolated from cloacal swabs and from caecal contents. MIC of 1581 E. coli strains were determined by agar dilution test procedures. MIC of OTC for the investigated strains were either > or = 128 micrograms/ml (resistant) or < or = 4 micrograms/ml (susceptible). Even from undosed birds resistant strains were isolated frequently, especially from samples of caecal contents. Administration of bioptivet GB resulted in a statistically significant increase in the average MIC. Statistically higher average MIC were recorded among isolates from cloacal swabs only during application of the drug. For strains from caecal contents this could be demonstrated until the end of the experiment.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Chickens; Escherichia coli; Escherichia coli Infections; Intestines; Microbial Sensitivity Tests; Oxytetracycline; Poultry Diseases; Tetracycline Resistance

The efficacy of treatment with single dose administration of 5 drugs at different dosages to layer hens naturally infected with Mycoplasma gallisepticum was studied. The drugs were tiamulin, which was administered orally, tylosin (parenterally and orally), spiramycin (orally), long-acting oxytetracycline (parenterally) and tylosindihydrostreptomycin (parenterally). Cure was assessed by the absence of nasal discharge. The cure rate was significantly higher (P less than 0.05) in treated hens than in untreated hens, as early as 1 day after treatment. Remission for 33 days was achieved in 60% of hens treated with 100 mg oxytetracycline, in 100% of hens treated with 100 mg or 200 mg spiramycin, in 92% and 85% of hens treated with 100 mg tylosin, parenterally and orally, and in 89% and 88% of birds given 100 mg tiamulin and tylosin-dihydrostreptomycin, respectively.

Topics: Administration, Oral; Animals; Chickens; Dihydrostreptomycin Sulfate; Diterpenes; Drug Therapy, Combination; Injections, Intramuscular; Mycoplasma Infections; Oxytetracycline; Poultry Diseases; Spiramycin; Tylosin

Chickens were orally inoculated with Salmonella typhimurium and fed rations medicated with either 200 g/ton neomycin sulfate, 200 g/ton oxytetracycline, or a combination of 200 g/ton neomycin sulfate plus 200 g/ton oxytetracycline for 16 days. The incidence of salmonellosis was lower in chickens fed the combined antibiotics, and the numbers of viable S. typhimurium in feces were significantly fewer than in chickens receiving only one antibiotic. Chickens fed the combination also gained significantly more weight on less feed than those fed only one antibiotic.

Topics: Animals; Body Weight; Chickens; Drug Combinations; Drug Synergism; Feces; Food Additives; Male; Neomycin; Oxytetracycline; Poultry Diseases; Salmonella Infections, Animal; Salmonella typhimurium

Turkeys were given oxytetracycline (OTC) as a feed supplement at levels of 0 g, 50 g, and 200 g OTC per ton of feed. After 8, 16, and 18 weeks the birds were sacrificed and bacteria were isolated from heart blood and liver tissue. When these isolates were tested for resistance against eight antibiotics, a direct correlation was observed between the level of supplement and the level of antibiotic resistance in the bacterial isolates. In postmortem studies on the livers from birds consuming both levels of OTC, an increase in the occurrence of lesions was observed. The livers from control birds appeared to have more granulomas.

Topics: Animal Feed; Animals; Drug Resistance, Microbial; Food, Fortified; Liver; Liver Diseases; Male; Oxytetracycline; Poultry; Poultry Diseases; Turkeys

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.

Topics: Animals; Cecum; Chickens; Intestines; Neomycin; Oxytetracycline; Polymyxins; Poultry Diseases; Salmonella Infections; Salmonella Infections, Animal

Topics: Animal Feed; Animals; Bacterial Vaccines; Borrelia; Borrelia Infections; Chickens; Drug Evaluation, Preclinical; Erythromycin; Furazolidone; Oxytetracycline; Poultry Diseases; Spectinomycin

The efficacy of short antimicrobial therapy was examined in chicks infected with S. infantis on the day of hatching. An attempt was made to prevent the reappearance of salmonellae by treating the chicks with a culture of cecal microflora to re-establish the normal intestinal flora. The following drugs were used: neomycin/polymyxin, oxytetracyline/neomycin, dihydrostreptomycin, furazolidone, and trimethoprim/sulphadiazine. The oxytetracycline/neomycin therapy was most effective, but reappearance of the infection was not avoided. Combined therapy with other antimicrobials and the culture reduced the number of infected chicks compared with the respective control groups. A slight reduction was also found when the culture was used alone without any preceding antimicrobial treatment.

Topics: Animals; Anti-Bacterial Agents; Cecum; Chickens; Neomycin; Oxytetracycline; Poultry Diseases; Salmonella; Salmonella Infections, Animal

Topics: Animals; Drug Resistance, Microbial; Oxytetracycline; Pasteurella; Pasteurella Infections; Poultry Diseases; Turkeys

Features of the anticoccidial activity of nicarbazin, amprolium, zoalene, sulphadimidine, diaveridine, Darvisul, spiramycin, chloramphenicol and oxytetracycline have been re-investigated both in vivo and in cell culture using Eimeria tenella. Of the drugs studied, only spiramycin was appreciably coccidiocidal, although nicarbazin and amprolium showed possibly slower coccidiocidal activity. In order to show activity against a particular stage in the life-cycle, higher concentrations of drug than those usually recommended for field usage had in most cases to be used. Under these conditions, parasites were usually inhibited as multinucleate 1st generation schizonts. With delayed medication, effects against 2nd generation parasites were in most cases found, and in many cases, although the parasites never matured to give viable merozoites, the large degenerating forms produced were able to cause extensive tissue destruction and haemorrhage. Methodology in this type of study is discussed in relation to more active and more recent anticoccidials, and some further experiments with robenidine reported.

Topics: Amprolium; Animals; Cells, Cultured; Chickens; Chloramphenicol; Coccidiosis; Coccidiostats; Dinitolmide; Eimeria; Leucomycins; Nicarbazin; Oxytetracycline; Poultry Diseases; Robenidine; Sulfaquinoxaline

Pseudomonas aeruginosa was isolated from the viscera of diseased and dead birds (young and adult chickens) as well as from 9 poultry houses on seven farms. Its typing was performed on the basis of the blue-green coloration of the cultures, their hemolytic activity, the pleasant odour of lime-tree, the growth in culturing at 42 degrees C, the presence of the pyocianin pigment, and the positive results of the cytochromoxidase test after Gaby and Hadley and the biochemical test after Kovacs. The pathogenicity of the agent was demonstrated through the experimental parenteral infection of chicks, albino mice, and guinea pigs. Pseudomonas aeruginosa cultures showed weak sensitivity and good resistance to the various drugs tested. Most active proved streptomycin, kanamycin, and spectam.

Topics: Ampicillin; Animals; Chickens; Chloramphenicol; Drug Combinations; Furazolidone; Guinea Pigs; Kanamycin; Mice; Oleandomycin; Oxytetracycline; Penicillin Resistance; Penicillins; Poultry Diseases; Pseudomonas aeruginosa; Pseudomonas Infections; Spectinomycin; Streptomycin; Sulfadiazine; Sulfamerazine; Sulfathiazoles

A natural occuring outbreak of aflatoxicosis was observed in Bobwhite quail chicks while on a brooding experiment. A slight reduction in effects was noted for birds which received Tylan in the water from 0-3 days and Terramycin from 0-35 days of age. No symptoms of aflatoxicosis were observed in birds which received a product (FloxAid) containing two antibiotics and eight vitamins from 0-14 days. It is postulated that the primary mode of protection was via the water soluble vitamin D content of the product with possibly some protection from vitamins A, E and K.

Topics: Aflatoxins; Animals; Cholecalciferol; Choline; Folic Acid; Housing, Animal; Leucomycins; Oxytetracycline; Penicillin G Procaine; Poultry Diseases; Pyridoxine; Quail; Streptomycin; Vitamin A; Vitamin B 12; Vitamin E; Vitamin K

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Chickens; Chloramphenicol; Drug Resistance, Microbial; Escherichia coli; Extrachromosomal Inheritance; Feces; Furazolidone; Humans; Intestines; Oxytetracycline; Poultry Diseases; Public Health; R Factors; Salmonella; Salmonella Infections; Salmonella Infections, Animal; Salmonella Phages; Salmonella typhimurium; Shigella; Swine; Tetracycline

Topics: Animals; Anti-Bacterial Agents; Chickens; Clostridium; Clostridium Infections; Intestinal Absorption; Oxytetracycline; Penicillin G; Poultry Diseases

Topics: Ampicillin; Animals; Anti-Bacterial Agents; Chickens; Chloramphenicol; Chlortetracycline; Furazolidone; Morpholines; Neomycin; Nitrofurans; Oxazoles; Oxytetracycline; Poultry Diseases; Rectum; Salmonella Infections, Animal; Salmonella typhimurium; Sulfamethazine

Topics: Animals; Anti-Bacterial Agents; Cell-Free System; Cells, Cultured; Chick Embryo; Chickens; Chlortetracycline; Dihydrostreptomycin Sulfate; Erythromycin; Fibroblasts; Herpesviridae; Marek Disease; Mycoplasma Infections; Neomycin; Oxytetracycline; Penicillin G; Poultry Diseases; Spectinomycin; Turkeys; Viral Plaque Assay; Viral Vaccines

Topics: Administration, Oral; Animal Feed; Animals; Anti-Infective Agents; Bacterial Infections; Ducks; Escherichia coli Infections; Female; Furazolidone; Male; Oxytetracycline; Pasteurella Infections; Poultry Diseases; Pyrimidines; Quinoxalines; Salmonella Infections, Animal; Sulfadimethoxine; Sulfonamides

Topics: Air Sacs; Animal Feed; Animals; Autopsy; Body Weight; Chickens; Chloramphenicol; Escherichia coli Infections; Furazolidone; Nitrofurans; Oxytetracycline; Poultry Diseases; Sulfonamides; Time Factors

Topics: Animals; Anti-Bacterial Agents; Ascaridia; Ascaridiasis; Chickens; Dose-Response Relationship, Drug; Oxytetracycline; Poultry Diseases

Topics: Animals; Anti-Bacterial Agents; Bacitracin; Body Weight; Chloramphenicol; Chlortetracycline; Embryo, Nonmammalian; Enteritis; Intestines; Microbial Sensitivity Tests; Neomycin; Oxytetracycline; Penicillins; Poultry Diseases; Staining and Labeling; Streptomycin; Turkeys; Viruses

Topics: Administration, Oral; Animals; Bacterial Infections; Chickens; Oxytetracycline; Poultry Diseases; Solutions

Topics: Animals; Anti-Infective Agents, Local; Beak; Brain; Chickens; Congenital Abnormalities; Eye Abnormalities; Hindlimb; Oxytetracycline; Poultry Diseases

Topics: Animal Feed; Animals; Chickens; Food Additives; Oxytetracycline; Poultry Diseases

Topics: Aerosols; Animals; Chickens; Injections; Oxytetracycline; Poultry Diseases

Topics: Animals; Anti-Infective Agents, Local; Antifungal Agents; Chickens; Hydantoins; Iodides; Oxytetracycline; Pasteurella Infections; Polyvinyls; Poultry Diseases; Sulfathiazoles

Topics: Animals; Chickens; Chlortetracycline; Oxytetracycline; Poultry Diseases; Protozoan Infections; Protozoan Infections, Animal; Tetracycline

Topics: Animals; Coccidiosis; Dietary Proteins; Intestinal Diseases, Parasitic; Oxytetracycline; Poultry Diseases

Topics: Animals; Dihydrostreptomycin Sulfate; Oxytetracycline; Penicillins; Poultry Diseases; Sepsis; Serositis

Topics: Animals; Anti-Bacterial Agents; Chickens; Chlortetracycline; Dihydrostreptomycin Sulfate; Drug Synergism; Mycoplasma Infections; Oxytetracycline; Poultry Diseases; Sulfates; Tetracycline

Topics: Acridines; Animals; Antiprotozoal Agents; Apicomplexa; Chickens; Chlortetracycline; Oxytetracycline; Poultry Diseases; Protozoan Infections; Protozoan Infections, Animal; Tetracycline

Topics: Animals; Chickens; Eggs; Hot Temperature; Humidity; Oxytetracycline; Poultry Diseases; Stress, Physiological

Topics: Animals; Chickens; Dactinomycin; Immunity; Orthomyxoviridae Infections; Oxytetracycline; Pasteurella Infections; Poultry Diseases

Topics: Animals; Chlortetracycline; Coccidiosis; Eimeria; Leucomycins; Oxytetracycline; Poultry Diseases

Topics: Animals; Epidemics; Humans; Occupational Diseases; Oxytetracycline; Pneumonia; Pneumonia, Viral; Poultry Diseases; Psittacosis; Radiography, Thoracic

Topics: Animals; Carnivora; Chickens; Disease; Horse Diseases; Horses; Meat; Oxytetracycline; Poultry; Poultry Diseases