tilmicosin and Actinobacillus-Infections

Porcine infectious pleuropneumonia caused by Actinobacillus pleuropneumoniae (App) is one of the most serious infectious diseases in pigs and has brought huge economic losses to the world pig industry. The aim of this trial was to evaluate the effect of enteric-coated tilmicosin granule in the treatment and control of artificial infection of App.. Sixty Duroc and Yorkshire crossbred pigs (50 of which were artificially infected) were divided into six groups: BCG (Blank control group), ICG (Infection-only control group), HDG (High-dose enteric-coated tilmicosin granules), MDG (Medium-dose enteric-coated tilmicosin granules), LDG (Low-dose enteric-coated tilmicosin granules) and TPG (Tilmicosin premix drug control group). The cure rate, mortality, clinical respiratory score, body temperature score, weight gain, lung score and so on were recorded.. The cure rate of HDG and MDG was as high as 90%, the mortality was 10%, and the clinical signs recovered quickly.. The results showed that enteric-coated tilmicosin granules had obvious therapeutic effect on artificial infection, which could reduce the damage caused by the disease and reduce the mortality.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Female; Male; Sus scrofa; Swine; Swine Diseases; Tablets, Enteric-Coated; Tylosin

To determine the effects of oral administration of tilmicosin in piglets experimentally infected with Actinobacillus pleuropneumoniae.. Forty 3-week-old specific-pathogen free piglets.. Piglets were assigned to 1 of 4 groups as follows: 1) uninfected sham-treated control piglets; 2) infected untreated piglets that were intratracheally inoculated with 10(7) CFUs of A pleuropneumoniae; 3) infected treated piglets that were intratracheally inoculated with A pleuropneumoniae and received tilmicosin in feed (400 ppm [microg/g]) for 7 days prior to inoculation; or 4) infected treated piglets that were intratracheally inoculated with A pleuropneumoniae and received chlortetracycline (CTC) in feed (1100 ppm [microg/gl) for 7 days prior to inoculation. Bronchoalveolar lavage (BAL) fluid and lung tissue specimens of piglets for each group were evaluated at 3 or 24 hours after inoculation. For each time point, 4 to 6 piglets/group were studied.. Feeding of CTC and tilmicosin decreased bacterial load in lungs of infected piglets. Tilmicosin delivered in feed, but not CTC, enhanced apoptosis in porcine BAL fluid leukocytes. This was associated with a decrease in LTB4 concentrations in BAL fluid of tilmicosin-treated piglets, compared with untreated and CTC-treated piglets, and also with a significant decrease in the number of pulmonary lesions. Tilmicosin inhibited infection-induced increases in rectal temperatures, as measured in untreated and CTC-treated piglets. Pulmonary neutrophil infiltration and prostaglandin E2 concentrations in the BAL fluid were not significantly different among groups at any time.. Oral administration of tilmicosin to infected piglets induces apoptosis in BAL fluid leukocytes and decreases BAL fluid LTB4 concentrations and inflammatory lung lesions.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animal Feed; Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Dinoprostone; Leukocytes; Leukotriene B4; Macrolides; Peroxidase; Phagocytosis; Pneumonia, Bacterial; Swine; Swine Diseases; Tylosin

The efficacy of tilmicosin administered in the feed to control Actinobacillus pleuropneumoniae infections in pigs was evaluated through a multisite, multitrial study. For each of 6 trials, 48 pigs (stratified by weight and sex) were randomly assigned to 6 to 8 pens. Medicated feed containing tilmicosin (200 g/t) and unmedicated feed were randomly assigned at the pen level and were provided ad libitum from day -7 to trial termination (day 14). Seeder pigs (inoculated intranasally with A. pleuropneumoniae serotype 1 and showing signs of clinical disease) were introduced to each pen on day 0. Rates of death, gross lesions, and culture of A. pleuropneumoniae at necropsy, clinical scores, average daily gain in weight, and average body temperature were compared between the medicated and unmedicated pigs. Compared with the unmedicated pigs, significantly fewer (P < 0.05) pigs given tilmicosin had lesions typical of A. pleuropneumoniae or had A. pleuropneumoniae isolated from their tissues at necropsy. Together with a significant reduction (P < 0.05) in the average percentage of pneumonic lung involvement (both visually and by weight), there were reductions in the numbers of pigs with moderate and severe pneumonic lung lesions and with A. pleuropneumoniae associated mortality. With tilmicosin treatment, the average daily weight gain, daily temperature, abdominal appearance, attitude, and respiration were also significantly better (P < 0.05). The results of this study demonstrate the in vivo effectiveness of tilmicosin (200 g/t) in controlling pleuropneumonia among swine experimentally infected with A. pleuropneumoniae.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Administration, Oral; Animal Feed; Animals; Female; Macrolides; Male; Quebec; Swine; Swine Diseases; Treatment Outcome; Tylosin

A double-blind randomized clinical trial was carried out to investigate the efficacy of tilmicosin (Pulmotil premix) for the treatment of a clinical outbreak of Actinobacillus pleuropneumoniae infection in growing-finishing pigs. The effects of tilmicosin administration in the feed at 400 mg/kg and an injection therapy of clinically diseased pigs with long-acting oxytetracycline (Terramycine LA) at 20 mg/kg bodyweight were compared. Both groups, totalling 147 pigs, were compared during a medication period of 15 days and a post-medication period of 11 days by means of different clinical and performance parameters. During the medication period, the tilmicosin group showed a significant advantage with respect to the number of new disease cases (P < 0.01), and a non-significant advantage regarding the number of removed pigs (P = 0.16), the number of sick pigs that recovered (P = 0.27) and the time to recovery (P = 0.42). During the post-medication period, the pigs of the tilmicosin group showed numerical non-significant benefits (P > 0.05) with respect to the clinical parameters. During the overall study period (26 days), the average daily gain and the feed conversion ratio were both significantly (P < 0.01) better in pigs from the tilmicosin group compared with pigs from the oxytetracycline group. This study demonstrated that in-feed medication of tilmicosin at a dosage of 400 mg/kg is efficacious for the treatment of a clinical respiratory disease outbreak of A. pleuropneumoniae infection in growing-finishing pigs. Compared with oxytetracycline injection of clinically diseased pigs, the tilmicosin treatment is particularly beneficial in the prevention of new disease cases while increasing or maintaining the performance of the pigs.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animal Feed; Animals; Anti-Bacterial Agents; Belgium; Disease Outbreaks; Dose-Response Relationship, Drug; Double-Blind Method; Female; Macrolides; Male; Swine; Swine Diseases; Time Factors; Tylosin

To determine the effective dosage of tilmicosin phosphate when fed to pigs for the control of pneumonia attributable to Actinobacillus pleuropneumoniae.. Randomized complete block design, with initial weight as the blocking factor.. Seeder pigs were used to infect clinically normal male and female pigs weighing between 13.6 and 36.3 kg at each of 4 trials.. Five doses of tilmicosin phosphate (0, 100, 200, 300, and 400 micrograms/g) were fed to pigs for 21 days. Pigs received experimental feeds 7 days before the seeder pigs were placed into pens. Feeding continued for an additional 14 days, with seeder pigs removed 3 to 8 days after placement. All pigs were euthanatized and necropsied, with lung bacterial flora and percentages of pneumonic involvement determined.. Improvement in clinical impression score, daily rectal temperature, and weight gain were seen for all doses of tilmicosin, compared with controls. For the same variables, tilmicosin administered at 200 to 400 micrograms/g resulted in improvements over the 100 micrograms/g dose.. Data indicate that tilmicosin phosphate fed to pigs at 200 to 400 micrograms/g is effective in controlling and preventing A pleuropneumoniae-induced pneumonia, when administered in feed for 21 days.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animal Feed; Animals; Anti-Bacterial Agents; Body Temperature; Dose-Response Relationship, Drug; Female; Food, Fortified; Macrolides; Male; Pneumonia, Bacterial; Swine; Swine Diseases; Tylosin; Weight Gain

To determine and evaluate the efficacy of the dose range of tilmicosin phosphate fed to pigs for control of pneumonia attributable to Actinobacillus pleuropneumoniae during episodes of clinical disease in commercial herds.. 12 trials were run in 9 geographic locations in herds with a history of pneumonia caused by A pleuropneumoniae.. Clinically normal male and female pigs of various body weights.. Two doses of tilmicosin phosphate (200 and 400 micrograms/g) and a 0 dose were administered in the feed for 21 days. Variables for determining efficacy were daily independent composite clinical impression score, individual pig weight, mortality, percentage of pneumonic involvement, and frequency of isolation of bacterial pathogens.. Medicated pigs had significantly lower mortality attributed to pneumonia than did nonmedicated pigs. In trials with confirmed pneumonia caused by A pleuropneumoniae or Pasteurella multocida, weight gain, feed conversion, and clinical impression scores were significantly improved in the pigs receiving 200 or 400 micrograms/g of tilmicosin, compared with nonmedicated pigs.. The clinical field trials reported here confirm that tilmicosin in the feed at 200 micrograms/g is effective for control of swine pneumonia attributable to A pleuropneumoniae or P multocida.. Under the moderate natural challenge conditions encountered, tilmicosin at 400 micrograms/g was not different from tilmicosin at 200 micrograms/g.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animal Feed; Animals; Anti-Bacterial Agents; Dose-Response Relationship, Drug; Female; Food, Fortified; Macrolides; Male; Pasteurella Infections; Pasteurella multocida; Pneumonia, Bacterial; Swine; Swine Diseases; Tylosin

The aim of this study was to evaluate the efficacy of in-feed medication with tilmicosin phosphate in order to eliminate or reduce the carriage of Actinobacillus pleuropneumoniae in the tonsils of carrier pigs. Two groups of 6 carrier animals received either a non-medicated feed (control group) or feed medicated with 400 ppm of tilmicosin phosphate (treated group) for 30 d. Three sentinel pigs were then introduced in each group and left for 29 d. The presence of A. pleuropneumoniae in tonsils was monitored using several techniques, including polymerase chain reaction (PCR). At the end of the treatment all of the control animals, but only 1 treated pig, were positive by PCR from tonsillar surface material. However, at necropsy, all control and most treated animals, as well as 1 sentinel animal, in both groups were positive by PCR from whole tonsils. In conclusion, under the experimental conditions, in-feed treatment with 400 ppm of tilmicosin phosphate significantly reduced the presence of A. pleuropneumoniae on the surface of tonsils but was unable to completely eliminate the organism from deeper tonsillar tissues and to prevent bacterial shedding by carrier animals.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Carrier State; Macrolides; Palatine Tonsil; Random Allocation; Swine; Swine Diseases; Treatment Outcome; Tylosin

Tilmicosin is a novel macrolide antibiotic developed for exclusive use in veterinary medicine. Tilmicosin has been approved as a feed premix to control porcine respiratory disease associated with Pasteurella multocida and Actinobacillus pleuropneumoniae. The development of antimicrobial susceptibility testing guidelines for tilmicosin was predicated on the relationship of clinical efficacy studies that demonstrated a favorable therapeutic outcome, on pharmacokinetic data, and on in vitro test data, as recommended by the National Committee for Clinical Laboratory Standards (NCCLS). The approved breakpoints for the minimum inhibitory concentration dilution testing for both species are resistant, > or = 32 microg/ml, and susceptible, < or = 16 microg/ml. The zone of inhibition interpretive criteria for disk diffusion testing with a 15-microg tilmicosin disk are resistant, < or = 10 mm, and susceptible, > or = 11 mm.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Diffusion; Drug Resistance, Bacterial; Erythromycin; Macrolides; Microbial Sensitivity Tests; Pasteurella Infections; Pasteurella multocida; Swine; Swine Diseases; Tylosin

The present study was aimed at scrutinizing the efficacy of oral antimicrobial treatments at experimental challenge using a strain of Actinobacillus pleuropneumoniae serotype 2 known to cause severe disease. SPF pigs aged 10 weeks were infected intranasally and the antimicrobial treatments were initiated 5 h prior to that exposure. Several antimicrobial drugs, as well as the length of the treatment period, were elucidated. The outcome of the challenge was monitored by registration of clinical symptoms, weight gains and the development of serum antibodies to A. pleuropneumoniae. At necropsy, the magnitude of pathological lesions in the respiratory tract and the rate of reisolation of the infective strain were recorded. Animals that became diseased displayed a decreased growth rate caused, to a large extent, by a reduced feed intake. The performance with respect to daily weight gain and feed conversion corresponded well with the clinical signs developed and serologic reactions, as well as with the findings made at necropsy. The results obtained among pigs treated with enrofloxacin, but also with florfenicol or chlortetracycline, were superior to those of pigs treated with penicillin, tiamulin or tilmicosin. A positive effect was obtained using a strategic in-feed medication against infection with A. pleuropneumoniae. Provided that the drug used is effective against the target microbe, initiating treatment prior to infection appeared to be more important than the length of the treatment. It should, however, be remembered that A. pleuropneumoniae was reisolated from all but one medicated group following an experimental challenge given after initiating the medication. Consequently medical treatment as described did not eradicate the microbe.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Administration, Oral; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Chlortetracycline; Diterpenes; Enrofloxacin; Fluoroquinolones; Macrolides; Penicillin V; Quinolones; Swine; Swine Diseases; Thiamphenicol; Tylosin

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Australia; Macrolides; Microbial Sensitivity Tests; Pasteurella Infections; Pasteurella multocida; Swine; Swine Diseases; Tylosin

Sixty one strains of Pasteurella multocida and 35 strains of Actinobacillus pleuropneumoniae isolated from pneumonic lesions of porcine lungs during the period from 1985 to 1989 in Japan were tested for antibiotic susceptibility to chlortetracycline (CTC), thiamphenicol (TP), tylosin (TS), acetylisovaleryl-tylosin (AIV-TS), tilmicosin (TMS), mirosamycin (MRM). Most strains of both species were sensitive to CTC, TP and TMS. Growth of fifty-one strains (83.6%) and forty-six strains (75.4%) of P. multocida were inhibited with 3.13 micrograms/ml of CTC and 0.78 micrograms/ml of TP, respectively. TS showed low activity against almost all strains (MIC > or = 6.25 micrograms/ml). Fifty-eight (95.1%), twenty-three (37.7%) and fifty (82%) of P. multocida showed MICs of > or = 6.25 micrograms/ml against AIV-TS, TMS and MRM, respectively. The MICs of A. pleuropneumoniae against CTC were less than 1.56 micrograms/ml. Thirty-two strains (91.4%) and 33 strains (94.3%) of A. pleuropneumoniae were inhibited with 3.13 micrograms/ml of TP and TMS respectively. However, TS, AIV-TS and MRM showed low activity against all of A. pleuropneumoniae (MIC > or = 6.25 micrograms/ml). Three different resistance patterns were observed in P. multocida and two in A. pleuropneumoniae isolates, respectively.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Japan; Macrolides; Microbial Sensitivity Tests; Pasteurella Infections; Pasteurella multocida; Pneumonia, Bacterial; Serotyping; Swine; Swine Diseases; Tylosin