tiamulin and Bacterial-Infections

Tiamulin hydrogen fumarate is a semisynthetic derivative of the diterpene antibiotic pleuromutilin used in poultry medicine to treat mainly Mycoplasma- and Brachyspira-related diseases. Its use over 30 yr has not generally increased the development of resistance to these pathogens but occasionally resistant isolates are encountered. Tiamulin administered at therapeutic levels is relatively quickly absorbed, metabolized in the liver, and eliminated from the body of the bird after a withdrawal period of 72 h, and as a result, meat products can be safely consumed. A zero withdrawal period for eggs has been granted in several European Union states. When administered with different drugs, tiamulin has been shown to have an enhanced activity with the tetracyclines. There is a strong interaction, even death, with the ionophore anticoccidials monensin, narasin, and salinomycin when tiamulin is used at therapeutic levels, but this is dose-related and low doses do not interact. It is thought to be caused by the preferential metabolism of tiamulin in the liver resulting in a build up of the ionophore leading to clinical signs of overdosage. Tiamulin shows a milder interaction, such as temporary growth depression, with maduramicin and semduramicin but is compatible with lasalocid. Although tiamulin shows small benefits in improving performance in healthy animals, its main production benefit is in the face of infection, as a true therapeutic antibiotic.

Topics: Animals; Anti-Bacterial Agents; Bacterial Infections; Diterpenes; Poultry; Poultry Diseases

In order to investigate the effects of tiamulin, neomycin, tetracycline, fluorophenicol, penicillin G, Linco-Spectin (0.15 mg mL(-1) lincomycin + 0.3 mg mL(-1) spectinomycin), erythromycin and oxytetracycline on controlling bacterial contaminations of the river buffalo semen, 120 mL diluted buffalo bull semen (diluted by tris-egg yolk extender) was divided into 5 mL tubes after initial evaluation and before (control sample) and at 0, 2, 6, 12 and 24 h after adding each of the above antibiotics at the recommended dose (D) and twice the recommended dose (Dx2) to the semen samples, each sample was cultured 4 times on Muller-Hinton agar medium and the results were recorded after 18 h incubation at 37 degrees C. Tiamulin, tetracycline, neomycin and fluorophenicol were ineffective. Oxytetracycline was effective in both D and Dx2 (p < 0.001). Penicillin G in both D and Dx2 was effective (p < 0.001). Linco-Spectin was effective, though not significant, in D at 2 h and in Dx2 at 0 h only. Erythromycin in D was not significantly effective, but, in Dx2 was effective (p < 0.001). Duration of the antibiotic exposure had no significant effect on the antibiotic potentials except for Linco-Spectin at 2 h (p < 0.014). The biochemical tests identified the contaminant bacteria as being a member of Arcanobacter (Corynebacterium) sp. In the next step, the semen sample of the same bull was taken, semen quality tests were carried out and the semen was diluted with the same extender (tris-egg yolk) + 7% glycerol, containing a double dose (Dx2) of these antibiotics and semen quality tests were carried out immediately after dilution, 18 h after storage at 4 degrees C and after the semen was packed in the straws, frozen in liquid nitrogen (-196 degrees C) and later thawed in 37 degrees C water bath to investigate whether these antibiotics have any adverse effect on the spermatozoa during the process of freezing and thawing. The comparison of the results with those of the control group (the sample undergone the same process without adding antibiotics) indicated that oxytetracycline adversely affected sperm motility at 0 and 18 h, all the antibiotics had a lower percentage of sperm abnormal morphology than the control at 0 and 18 h, except for Linco-Spectin at 18 h and after freezing-thawing and tetracycline after freezing and thawing the sample which were the same as the control. Sperm viability was not affected by antibiotics before and after freezing. It was concluded that oxytetr

Topics: Animals; Anti-Bacterial Agents; Bacterial Infections; Buffaloes; Diterpenes; Erythromycin; Lincomycin; Male; Neomycin; Oxytetracycline; Penicillin G; Semen; Spectinomycin; Temperature; Tetracycline; Thiamphenicol

Tiamulin is a pleuromutilin derivative used in veterinary practice for the control and specific therapy of infections in swine. This report summarizes studies to establish standardized susceptibility testing methods, interpretive criteria, and reagent details for use in veterinary methods recently developed by the National Committee for Clinical Laboratory Standards (NCCLS) (standards M31-A and M37-A, NCCLS, Wayne, Pa., 1999). A total of 636 fastidious and nonfastidious animal and human pathogens were processed by using media and procedures described by the NCCLS. Tiamulin disk diffusion tests used a 30-microg disk concentration, and the proposed MIC breakpoints corresponding to levels achievable in animal target tissues (lung) were < or =4 microg/ml for susceptibility and > or =32 microg/ml for resistance. Correlate zone diameters for specific nonfastidious species were as follows: for Pasteurella multocida and staphylococci tested on Mueller-Hinton agar, susceptibility at > or =19 mm and resistance at < or =11 mm, and for Actinobacillus suis, Erysipelothrix rhusiopathiae, and Streptococcus suis tested on enriched chocolate Mueller-Hinton agar, susceptibility at > or =16 mm and resistance at < or =8 mm. When Actinobacillus pleuropneumoniae was tested, a susceptibility breakpoint of < or =16 microg/ml (> or =9 mm) was suggested for veterinary fastidious medium broth and enriched chocolate Mueller-Hinton agar. Absolute categorical agreement between NCCLS dilution and disk diffusion test results with these criteria ranged from 90.5 to 96.2%. Tiamulin susceptibility testing methods appear to be accurate in their categorical classification for indicated species, and their availability will allow immediate testing of animal isolates to guide therapy via appropriate levels of dosing and to monitor the development of resistance for agents in this unique class.

Topics: Anti-Bacterial Agents; Bacteria; Bacterial Infections; Diterpenes; Humans; Microbial Sensitivity Tests; Veterinary Medicine

In vitro and in vivo test were carried out with tiamulin and gram-negative bacterial pathogens of fish. Determination of minimum inhibitory concentration for 51 strains of seven species of gram-negative bacterial pathogens showed that only strains of Vibrio anguillarum were sensitive at 1.6-6.25 ppm, while the rest of test strains required 25- greater than 100 ppm. Control of infection was not achieved when tiamulin was fed for 14 days at 5 or 50 mg/kg to rainbow trout (Salmo gairdneri) experimentally infected with Yersinia ruckeri.

Topics: Aeromonas; Animals; Anti-Bacterial Agents; Bacterial Infections; Diterpenes; Enterobacteriaceae; Fish Diseases; Fishes; Gram-Negative Bacteria; Pseudomonas fluorescens; Trout; Vibrio; Yersinia; Yersinia Infections

The antibacterial effects of a combination of tiamulin and chlortetracycline in vitro against a number of field isolates of Pasteurella multocida, Haemophilus pleuropneumoniae and Bordetella bronchiseptica were examined. There was a marked synergism between the two antibiotics against all eight isolates of P multocida, against seven of nine isolates of H pleuropneumoniae and against the single strain of B bronchiseptica tested. Two field trials were carried out on a herd with a history of complicated enzootic pneumonia where the presence of Mycoplasma hyopneumoniae and P multocida had been established and subsequently the presence of H pleuropneumoniae was discovered. Feed containing tiamulin at 100 ppm combined with chlortetracycline at 300 ppm was given for seven days to pigs affected with pneumonia, and the results were compared with untreated controls and pigs receiving chlortetracycline at 300 ppm. There was a follow-up observation period of three weeks when all groups received unmedicated feed. During the medication period the combination treated groups showed a statistically significant increase in average daily weight gain of 156 g (20.4 per cent) and in feed conversion efficiency of 0.576 (20.8 per cent) and a numerical improvement in average disease score in comparison with the untreated controls. These improvements were approximately double those observed in the groups treated with 300 ppm chlortetracycline which showed improvements of 93 g (12.2 per cent) in average daily gain and 0.301 (10.9 per cent) in feed conversion efficiency. During the following three weeks most of the initial gains were lost, probably owing to the reinfection of the treated groups by the untreated controls.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Bacterial Infections; Chlortetracycline; Diterpenes; Drug Synergism; Drug Therapy, Combination; Microbial Sensitivity Tests; Pneumonia; Pneumonia of Swine, Mycoplasmal; Swine; Swine Diseases

The effects of tylosin tartrate and tiamutilin were examined in pneumonias induced experimentally in neonatal piglets with a homogenate of pneumonic pig lung, obtained from pigs with naturally acquired enzootic pneumonia. The homogenate contained mycoplasmas, including Mycoplasma hyopneumoniae (M suipneumoniae) and M hyorhinis, and certain bacteria and viruses. The experimental pneumonias generally resembled mycoplasmal pneumonia histologically but were complicated by aspiration pneumonia in some animals. both tylosin tartrate (50 mg/kg) and tiamutilin (10 mg/kg) administered orally twice daily for 10 days, beginning 14 days after intranasal infection, significantly reduced the incidence and severity of macroscopical pneumonic lung lesions. M hyopneumoniae could be isolated from the lungs of the unmedicated piglets, but not from drug-treated piglets. The numbers of M hyorhinis, Acholeplasma granularum, Haemophilus parasuis, Pasteurella multocida and P haemolytica in the lung tissue of the infected piglets were significantly reduced by drug therapy. The role of bacterial in the experimental infection appeared to be that of secondary invaders.

Topics: Animals; Anti-Bacterial Agents; Bacterial Infections; Diterpenes; Drug Therapy, Combination; Leucomycins; Pneumonia; Pneumonia of Swine, Mycoplasmal; Pneumonia, Aspiration; Pneumonia, Viral; Swine; Swine Diseases; Tylosin