oxytetracycline--anhydrous and Pleuropneumonia

Therapeutic management of contagious caprine pleuroneumonia (CCPP) involves mostly the use of oxytetracycline followed by enrofloxacin and rarely tylosin. In many parts of the world including India, the former antibiotics are commonly available than the latter. Therefore, prolonged use of the same leads to the development of antibiotic resistance and decreased efficacy of drug. Besides, inflammatory and allergic pathogenesis of CCPP envisages combination therapy. In this study, we evaluated the effectiveness of the combination therapy using different antibiotics (oxytetracycyline @ 10: group I, enrofloxacin @ 5 group II, and tylosin: group III, @ 10 mg/kg body weight), along with anti-inflammatory (meloxicam @ 0.5 mg/kg) and anti-allergic (pheneramine maleate @ 1.0 mg/kg) drugs. These drugs were given intramuscularly at the interval of 48 h for four times in three test groups (n = 10) of Pashmina goats, viz. groups I, II, and III, respectively, affected with CCPP. Group IV (n = 10) was kept as healthy control when group V (n = 10) treated with oxytetracycline @ 10 mg/kg alone was used as positive control. Clinical signs, clinical parameters, pro-inflammatory cytokine (tumor necrosis factor alpha (TNF-α)), and oxidative stress indices (total oxidant status (TOS), total antioxidant status (TAS)) were evaluated at hours 0, 48, 96, and 144 of experimental trial. Tylosin-based combination therapy resulted in a rapid and favorable recovery resulting in restoration of normal body temperature (102.46 ± 0.31 °F), respiration rate (16.30 ± 0.79 per minute), and heart rate (89.50 ± 2.63 per minute) compared to the oxytetracycline (102.95 ± 0.13, 21.30 ± 1.12, 86.00 ± 2.33, respectively) and enrofloxacin (102.97 ± 0.19, 21.00 ± 1.25, 90.00 ± 2.58, respectively) treated groups. By hour 144, all the groups showed restoration of clinical parameters of normal health and diminishing signs of CCPP, viz. fever, dyspnea, coughing, nasal discharge, weakness, and pleurodynia. Significant (P ≤ 0.05) decrease in levels of TNF-α and non-significant (P > 0.05) decrease in levels of TOS and an increase in levels of TAS were noted from hour 0 to 144 in all the test groups. Within the groups, no significant (P > 0.05) change was noted in TNF-α, TOS, and TAS levels; however, TNF-α levels were comparatively lower in group III. Hematological parameters did not differ significantly (P > 0.05). From these findings, it can be inferred that tylosin-based combination therapy is relatively be

Topics: Animals; Anti-Allergic Agents; Anti-Bacterial Agents; Anti-Inflammatory Agents, Non-Steroidal; Drug Therapy, Combination; Enrofloxacin; Female; Goat Diseases; Goats; India; Meloxicam; Oxytetracycline; Pheniramine; Pleuropneumonia; Pleuropneumonia, Contagious; Pneumonia, Mycoplasma; Tylosin

Actinobacillus pleuropneumoniae (App) is a Gram-negative bacterium that causes porcine pleuropneumonia, leading to economic losses in the swine industry. Due to bacterial resistance to antibiotics, new treatments for this disease are currently being sought. Lactoferrin (Lf) is an innate immune system glycoprotein of mammals that is microbiostatic and microbicidal and affects several bacterial virulence factors. The aim of this study was to investigate whether bovine iron-free Lf (BapoLf) has an effect on the growth and virulence of App. Two serotype 1 strains (reference strain S4074 and the isolate BC52) and a serotype 7 reference strain (WF83) were analyzed. First, the ability of App to grow in iron-charged BLf was discarded because in vivo, BapoLf sequesters iron and could be a potential source of this element favoring the infection. The minimum inhibitory concentration of BapoLf was 14.62, 11.78 and 10.56 µM for the strain BC52, S4074 and WF83, respectively. A subinhibitory concentration (0.8 µM) was tested by assessing App adhesion to porcine buccal epithelial cells, biofilm production, and the secretion and function of toxins and proteases. Decrease in adhesion (24-42 %) was found in the serotype 1 strains. Biofilm production decreased (27 %) for only the strain 4074 of serotype 1. Interestingly, biofilm was decreased (60-70 %) in the three strains by BholoLf. Hemolysis of erythrocytes and toxicity towards HeLa cells were not affected by BapoLf. In contrast, proteolytic activity in all strains was suppressed in the presence of BapoLf. Finally, oxytetracycline produced synergistic effect with BapoLf against App. Our results suggest that BapoLf affects the growth and several of the virulence factors in App.

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Apoproteins; Bacterial Adhesion; Bacterial Toxins; Biofilms; Cattle; Drug Synergism; HeLa Cells; Humans; Iron; Lactoferrin; Oxytetracycline; Pleuropneumonia; Swine; Swine Diseases; Virulence

The prophylactic effect of in-feed medication with oxytetracycline was tested by using an Actinobacillus pleuropneumoniae aerosol challenge model. Groups of 10 conventional pigs were provided with feed containing 400, 800, 1200 or 1600 mg oxytetracycline/kg and fed ad libitum. After six days of medication the pigs were challenged and clinical signs were recorded. Two groups of four unmedicated pigs served as controls and were euthanased 36 to 48 hours after challenge and dissected. The feed medication was continued for nine days after the challenge, and the different treatment groups were then moved to separate accommodation where they were mixed with seronegative tracer pigs. The steady state concentrations of oxytetracycline in the pigs' serum after six days medication with feed containing 400, 800, 1200 or 1600 mg oxytetracycline/kg ranged from 0.07 to 0.13, 0.21 to 0.46, 0.27 to 0.46 and 0.35 to 0.56 microgram/ml, respectively. One of the eight unmedicated control pigs died, and the other seven showed signs of pleuropneumonia post mortem. Medication with feed containing 400 mg and 800 mg oxytetracycline/kg failed to prevent pleuropneumonia in the challenged pigs, and the mortality rates in these groups were two out of 10 and one out of nine pigs, respectively. All the pigs given feed containing 1200 and 1600 mg oxytetracycline/kg survived and only two of the pigs in the first treatment group showed mild clinical signs. No clinical signs were observed in the tracer pigs which were mixed with the pigs medicated with 400, 800 or 1200 mg oxytetracycline/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Actinobacillus Infections; Actinobacillus pleuropneumoniae; Aerosols; Animal Feed; Animals; Netherlands; Oxytetracycline; Pleuropneumonia; Swine; Swine Diseases

In the present study the feed and water consumption and pharmacokinetic parameters of orally administered oxytetracycline were compared in clinically healthy pigs and in the same pigs following a challenge with Actinobacillus (Haemophilus) pleuropneumoniae toxins. Endobronchial challenge with A. pleuropneumniae toxins was accompanied by anorexia, increased lassitude, labored breathing, fever, and increased white blood cell counts. Pleuropneumonia was evident in all pigs on autopsy. Following the challenge, both feed and water consumption were markedly reduced. In contrast to recommendations in the literature, it is concluded that drugs should not be administered to pneumonic pigs via water. In healthy pigs the oral bioavailability of oxytetracycline (50 mg/kg), given on an empty stomach, was 4.8% and the elimination half-life (t1/2 beta) was 5.92 h. After challenge, the pigs showed great variation in oxytetracycline plasma concentrations. In addition, the mean computed elimination rate constant (beta), t1/2 beta, the area under the plasma concentration-time curve (AUC), and clearance in pneumonic pigs differed significantly (P less than .05) from the values found in healthy pigs. The elimination half-life (t1/2 beta), AUC, and volume of distribution (Vd area) were increased. In diseased pigs the mean of maximum plasma concentrations (.87 micrograms/ml) was reached after 7 h, in contrast to 1.74 h (1.87 micrograms/ml) in the healthy pigs.

Topics: Actinobacillus Infections; Administration, Oral; Animals; Biological Availability; Body Temperature; Drinking; Eating; Half-Life; Male; Oxytetracycline; Pleuropneumonia; Swine; Swine Diseases

These experiments tested the hypothesis that long-acting oxytetracycline (oxytetracycline-LA) was more effective than regular oxytetracycline in preventing porcine pleuropneumonia when administered either 24 or 48 h prior to experimental challenge with virulent strains of Actinobacillus pleuropneumoniae. Two experiments (1 and 2) were conducted using growing pigs (average weight 12-15 kg). Antibiotic treatments were administered once intramuscularly at 20 mg/kg body weight; controls received an equivalent volume of saline. Clinical signs were recorded over seven days, and mortality rates and pathological lesions were analyzed using analysis of variance. Serum oxytetracycline levels were compared 48 and 72 h postinjection. All pigs developed clinical disease following experimental infection. Actinobacillus pleuropneumoniae was recovered from 42% of experiment 1 pigs and all of experiment 2 pigs. The data showed that both oxytetracycline and oxytetracycline-LA given at the same dose protected pigs against experimental infection when given 24 h prior to challenge, and there was no difference between the efficacy of the two drugs in this experiment. When administered 48 h prior to challenge, only oxytetracycline-LA reduced the clinical signs and pathological changes following A. pleuropneumoniae challenge. Between 48 and 72 h postinjection, oxytetracycline-LA blood levels were significantly greater compared to oxytetracycline-treated pigs.

Topics: Actinobacillus Infections; Analysis of Variance; Animals; Delayed-Action Preparations; Haemophilus Infections; Oxytetracycline; Pleuropneumonia; Random Allocation; Specific Pathogen-Free Organisms; Swine; Swine Diseases

Topics: Adult; Aged; Aniline Compounds; Bronchiectasis; Bronchitis; Bronchopneumonia; Female; Humans; Lung Abscess; Lung Diseases; Male; Middle Aged; Oxytetracycline; Pleuropneumonia; Quaternary Ammonium Compounds; Respiratory Tract Infections; Toluene

Topics: Adolescent; Bronchial Fistula; Bronchoscopy; Chlortetracycline; Drainage; Humans; Liver Abscess; Liver Function Tests; Lung Abscess; Oxytetracycline; Pleuropneumonia; Staphylococcal Infections; Streptomycin; Surgical Procedures, Operative