oxytetracycline--anhydrous and Haemophilus-Infections

Three field trials were conducted in a large commercial feedlot in Saskatchewan to determine the prevalence of Haemophilus somnus in calves and to evaluate the efficacy of prophylactic mass medication with long-acting oxytetracycline on day 17 (1990, n = 1336), day 11 (1991, n = 4372), or day 8 (1992, n = 5632) postarrival. Hemophilosis accounted for > 40% of the mortality in feedlot calves each year. Haemophilus somnus was cultured from the blood of one febrile calf on day 1 (0.1%, n = 895), but it was not cultured from nasal swabs on day 1 or day 11 (n = 881) or from blood samples on day 11 (n = 883). Similarly, it was not cultured from nasal swabs or blood samples from sick calves first treated for bovine respiratory disease (BRD) (n = 219). Serological titers to H. somnus increased (p < 0.05) in unvaccinated calves from day 1 (Geometric mean titer = 11,846) to day 96 (Geometric mean titer = 63,712), indicating natural infection following feedlot entry. Calves that relapsed twice with BRD or died from BRD +/- hemophilosis had significantly (p < 0.06) lower titers to H. somnus on days 1 and 96 than those that did not relapse twice or die. Postarrival mass medication with long-acting oxytetracycline did not reduce (p > 0.05) the risk of hemophilosis mortality. However, it reduced (p < 0.05) the risk of BRD treatment by 14% and the risk of BRD mortality by 71%. Additional epidemiological studies of H. somnus are needed so that we can develop strategic medication and vaccination programs to reduce losses from hemophilosis.

Topics: Animals; Cattle; Cattle Diseases; Haemophilus Infections; Injections, Intramuscular; Lung Diseases; Male; Oxytetracycline; Pilot Projects; Prevalence; Saskatchewan

In a study of the diagnosis and treatment of Corynebacterium vaginale (Haemophilus vaginalis) vaginitis in 30 patients, clinical and microscopical findings were compared with laboratory cultures. The study also included a double-blind randomised trial of treatment regimens including placebo therapy. Laboratory cultures of C. vaginale corresponded well with clinical findings, and we suggest that C. vaginale vaginitis can be reliably diagnosed with clinical and microscopical findings. Tetracycline was effective in half the patients treated, whereas all but 1 of the 17 patients eventually treated with metronidazole were cured. The apparent discrepancy between in-vitro sensitivity and in-vitro efficacy of metronidazole in this condition is discussed.

Topics: Adolescent; Adult; Clinical Trials as Topic; Double-Blind Method; Drug Resistance, Microbial; Female; Gardnerella vaginalis; Haemophilus Infections; Humans; Metronidazole; Oxytetracycline; Vaginitis

Routine screening for sexually transmitted diseases in new patients attending the Genitourinary Clinic in Stoke-on-Trent includes a culture for Mycoplasma hominis (MH) and Ureaplasma urealyticum (UU). A retrospective study was carried out on 400 female patients to ascertain whether there were any significant differences between the group positive for MH and UU and the negative control group. The positive group were found to be younger on average, but to have similar sexual histories to the negative control group. An association was found between the presence of genital mycoplasmas and Gardnerella vaginalis. An odourous vaginal discharge was more common in the positive group. Erythromycin was ineffective in eradicating the organisms in 62.5% of patients with MH, and 70% of those with UU. Continuing work is required to identify those women in whom the presence of MH or UU could have pathogenic effects. Treatment regimens for this group of women need to be carefully reassessed, in the light of increasing antibiotic resistance.

Topics: Adult; Age Factors; Amines; Candidiasis, Vulvovaginal; Erythromycin; Female; Gardnerella vaginalis; Genital Diseases, Female; Haemophilus Infections; Humans; Mycoplasma; Mycoplasma Infections; Mycoplasmatales Infections; Oxytetracycline; Retrospective Studies; Ureaplasma

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

A long-acting oxytetracycline formulation was evaluated for control of rhinitis induced experimentally in pigs with a capsular type A, toxin-negative, low-passage strain of Pasteurella multocida. The pigs were 6 to 7 weeks old and were naturally infected with Haemophilus parasuis. The H parasuis infection was thought to predispose to establishment of P multocida in the nasal cavity. A long-acting oxytetracycline formulation was given IM at the rate of 20 mg/kg, 4 times at 5-day intervals. Medication reduced (P less than 0.05) the severity of turbinate atrophy and the proportion of pigs with P multocida and H parasuis in their nasal cavities. Numbers of colonies of P multocida and H parasuis isolated were also less in medicated pigs.

Topics: Animals; Haemophilus Infections; Oxytetracycline; Pasteurella Infections; Rhinitis, Atrophic; Swine; Swine Diseases

Topics: Ampicillin; Anti-Bacterial Agents; Floxacillin; Gentamicins; Haemophilus Infections; Haemophilus influenzae; Humans; Klebsiella Infections; Klebsiella pneumoniae; Mycoplasma Infections; Oxytetracycline; Penicillin G; Penicillin Resistance; Pneumonia; Streptococcal Infections

Topics: Arthritis; Arthritis, Reactive; Female; Haemophilus Infections; Humans; Hypersensitivity; Inclusion Bodies; Male; Mycoplasma Infections; Mycoses; Oxytetracycline; Tetracycline; Trichomonas vaginalis; Urethritis; Uveitis

Topics: Chloramphenicol; Chlortetracycline; Demeclocycline; Drug Resistance, Microbial; Haemophilus Infections; Humans; Methacycline; Oxytetracycline; Rolitetracycline; Salmonella Infections; Tetracycline