Comparing clinical effects of marbofloxacin and gamithromycin in goat kids with pneumonia The aim of this study was to compare the clinical efficacy of a single-dose of gamithromycin (GM) or marbofloxacin (MR) in kids with naturally occurring pneumonia. Thirty-six kids, aged 2-2.5 months, with body weight ranging from 12 kg to 18 kg were presented with clinical signs of pneumonia. The most
Pharmacokinetics and pharmacodynamics of gamithromycin in pulmonary epithelial lining fluid in naturally occurring bovine respiratory disease in multisource commingled feedlot cattle. The objectives of this study were to determine (i) whether an association exists between individual pharmacokinetic parameters and treatment outcome when feeder cattle were diagnosed with bovine respiratory disease (BRD) and treated with gamithromycin (Zactran(®) ) at the label dose and (ii) whether there was a stronger association between treatment outcome and gamithromycin concentration in plasma or in the pulmonary epithelial lining fluid (PELF) effect compartment. The study design was a prospective, blinded, randomized clinical trial utilizing three groups of 60 (362-592 lb) steers/bulls randomly allocated
Immunomodulatory properties of gamithromycin and ketoprofen in lipopolysaccharide-challenged calves with emphasis on the acute-phase response. Macrolide antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) have been reported to be modulators of the innate immune response, irrespectively of their antimicrobial and anti-inflammatory actions. Therefore, it was our objective to evaluate whether the macrolide gamithromycin (GAM) and the NSAID ketoprofen (KETO) attenuate the acute-phase response in calves, and whether their combined administration is beneficial due to synergistic and/or additive effects. To this end, both drugs, as well as their combination, were studied in a previously developed inflammation model, i.e., the induction of an acute-phase response by an intravenous
Efficacy of gamithromycin for the treatment of foals with mild to moderate bronchopneumonia. Gamithromycin is active in vitro against the bacterial agents most commonly associated with bronchopneumonia in older foals. However, the clinical efficacy and safety of this drug have not been investigated. Gamithromycin is effective for the treatment of bronchopneumonia in foals. One hundred and twenty -one foals on a farm endemic for infections caused by Rhodococcus equi. In a controlled, randomized, and double blinded clinical trial, foals with ultrasonographic evidence of pulmonary abscesses (abscess score 8.0-20 cm) were randomly allocated in 3 treatment groups: (1) gamithromycin IM q7 days (n = 40); (2) azithromycin with rifampin, PO q24h (n = 40); or (3) no antimicrobial treatment (controls
Synovial fluid pharmacokinetics of tulathromycin, gamithromycin and florfenicol after a single subcutaneous dose in cattle Deep digital septic conditions represent some of the most refractory causes of severe lameness in cattle. The objective of this study was to determine the distribution of tulathromycin, gamithromycin and florfenicol into the synovial fluid of the metatarsophalangeal (MTP points up to 240 hours post-injection, and samples were analyzed for drug concentration. In synovial fluid, florfenicol pharmacokinetic parameters estimates were: mean Tmax 7 +/- 2 hours, mean t½ 64.9 +/- 20.1 hours and mean AUC0-inf 154.0 +/- 26.2 ug*h/mL. Gamithromycin synovial fluid pharmacokinetic parameters estimates were: mean Tmax 8 hours, mean t½ 77.9 +/- 30.0 hours, and AUC0-inf 6.5 +/- 2.9 ug
Field study of the comparative efficacy of gamithromycin and tulathromycin for the control of undifferentiated bovine respiratory disease complex in beef feedlot calves at high risk of developing respiratory tract disease. To compare the efficacy of gamithromycin with that of tulathromycin for control of undifferentiated bovine respiratory disease complex (BRDC) in feedlot calves. 2,529 weaned crossbred beef calves. At each of 2 feedlots, calves at risk of developing BRDC were administered a single dose of gamithromycin (6.0 mg/kg, SC; n = 1,263) or tulathromycin (2.5 mg/kg, SC; 1,266) metaphylactically. Health (BRDC morbidity, mortality, case-fatality, and retreatment rates) and performance (average daily gain, dry matter intake, and feed-to-gain ratio) outcomes were compared between
Field study of the comparative efficacy of gamithromycin and tulathromycin for the treatment of undifferentiated bovine respiratory disease complex in beef feedlot calves. To compare the efficacy of gamithromycin with that of tulathromycin for the treatment of undifferentiated bovine respiratory disease complex (BRDC) in feedlot calves. 1,049 weaned crossbred beef calves. At each of 6 feedlots , newly arrived calves with BRDC were administered a single dose of gamithromycin (6.0 mg/kg, SC; n = 523) or tulathromycin (2.5 mg/kg, SC; 526). Case-fatality and BRDC retreatment rates during the first 120 days after treatment, final body weight, and average daily gain (ADG), were compared between treatments. At 2 feedlots, calves were assigned clinical scores for 10 days after treatment to determine
neither revealed a macrolide resistance gene nor a macrolide resistance-mediating mutation. The isolates from 2008 and 2019 were resistant to erythromycin, tilmicosin, tildipirosin, tulathromycin and gamithromycin and showed either only the A2058G mutation in all six 23S rRNA operons or the chromosomally located macrolide resistance genes msr(E) and mph(E), respectively. The isolate from 2021 was resistant to erythromycin, tulathromycin, gamithromycin and tylosin and carried a novel integrative and conjugative element of 64 966 bp, designated Tn7730, in its chromosomal DNA. It harboured the macrolide resistance genes mef(C), mph(G) and estT, the lincosamide resistance gene lnu(H), and the tetracycline resistance gene tet(Y), the last two were detected for the first time in P. multocida. Macrolide
. haemolytica identified as being highly resistant (MICs >64 mg/L) to the macrolides erythromycin, gamithromycin, tilmicosin, tildipirosin and tulathromycin were screened by multiplex PCR for the previously identified resistance genes erm(42), msr(E) and mph(E). Strains lacking these determinants were analysed by genome sequencing and primer extension on the rRNAs. Macrolide resistance in one M. haemolytica
on strains that are negative for erm(42), msr(E), and mph(E). The multiplex system has been tested on more than 40 selected isolates of P. multocida and M. haemolytica and correlated with MICs for the veterinary macrolides tulathromycin and tilmicosin, and the newer compounds gamithromycin and tildipirosin. The multiplex PCR system gives a rapid and robustly accurate determination of macrolide resistance
Demonstration of the metaphylactic use of gamithromycin against bacterial pathogens associated with bovine respiratory disease in a multicentre farm trial. On five commercial cattle rearing sites across Europe, a total of 802 young cattle at high risk of developing bovine respiratory disease (BRD) associated with the bacterial pathogens Mannheimia haemolytica or Pasteurella multocida and/or Mycoplasma bovis were enrolled into a multicentre, controlled field trial. Half were treated with a single dose of gamithromycin at 6 mg/kg bodyweight by subcutaneous injection and half received an injection of a saline placebo as the control. All animals were observed daily for 14 days for signs of BRD as defined by set criteria. The proportion of metaphylactic preventive treatment successes, defined
Determination of the duration of antibacterial efficacy following administration of gamithromycin using a bovine Mannheimia haemolytica challenge model. The antibacterial efficacy of gamithromycin administered once 1, 5, or 10 days prior to a challenge infection with Mannheimia haemolytica serotype A1 was evaluated. Forty calves were randomly allocated on day -11, restricted by body weight , to one of three treatment groups given gamithromycin at 6 mg/kg of body weight 10, 5, or 1 days before challenge or to an untreated control group. M. haemolytica A1 challenge infections were induced on day 0 by depositing 7.4 × 10(7) CFU at the bifurcation of the main bronchus using a bronchoscope. Clinical observations were made daily from the day of allocation to day 10, when necropsy was scheduled
(enrofloxacin 2.5 μg/ml; marbofloxacin 5 μg/ml) were observed against one strain (MycSu17) and extremely high MIC values of macrolides and lincomycin (tilmicosin, tulathromycin and lincomycin >64 μg/ml; gamithromycin 64 μg/ml; tylosin 32 μg/ml and tylvalosin 2 μg/ml) were determined against another, outlier strain (MycSu18). Amino acid changes in the genes gyrA (Gly81Ala; Ala83Val; Glu87Gly, according