tiamulin and florfenicol

The clinical efficacy of tulathromycin in the treatment of natural outbreaks of swine respiratory disease (SRD) was evaluated at five European sites. Pigs (1 to 6 months of age) exhibiting clinical signs of SRD were treated intramuscularly with tulathromycin (n = 247) at 2.5 mg/kg on day 0 versus either tiamulin (n = 102) at 15 mg/kg on days 0, 1, and 2 (Germany, the Netherlands, and the United Kingdom) or florfenicol (n = 20) at 15 mg/kg on days 0 and 2 (France). Actinobacillus pleuropneumoniae, Pasteurella multocida, and Mycoplasma hyopneumoniae infections were the most frequently diagnosed pathogens. For both tulathromycin-treated animals and those treated with tiamulin or florfenicol, there were significant (P = .0001) reductions in mean rectal temperature and the severity of abnormal clinical signs on days 2 and 10 compared with day 0. There were no significant differences (P > .05) between treatments in average daily weight gain. Tulathromycin was found to be safe and highly effective in the treatment of natural outbreaks of SRD.

Topics: Animals; Anti-Bacterial Agents; Disaccharides; Disease Outbreaks; Diterpenes; Europe; Heterocyclic Compounds; Injections, Intramuscular; Pasteurellosis, Pneumonic; Severity of Illness Index; Swine; Swine Diseases; Thiamphenicol; Treatment Outcome

Mycoplasma synoviae (MS) is a highly prevalent bacterial species in poultry causing disease and severe economic losses. Antibiotic treatment is one of the control strategies that can be applied to contain clinical outbreaks in MS-free flocks, especially because this bacterium can be transmitted in ovo. It becomes, then, very important for veterinarians to know the antibiotic susceptibility of the circulating strains in order to choose the most appropriate first-line antibiotic molecule as a proactive role in fighting antibiotic resistance. We evaluated the Minimum Inhibitory Concentrations (MICs) of enrofloxacin, oxytetracycline, doxycycline, erythromycin, tylosin, tilmicosin, spiramycin, tiamulin, florfenicol and lincomycin for MS isolates collected between 2012 and 2017 in Italy. A total of 154 MS isolates from different poultry commercial categories (broiler, layer, and turkey sectors) was tested using commercial MIC plates. All MS isolates showed very high MIC values of erythromycin (MIC90 ≥8 μg/mL) and enrofloxacin (MIC90 ≥16 μg/mL). MIC values of doxycycline and oxytetracycline obtained were superimposable to each other with only a one-fold dilution difference. Discrepancies between MIC values of tylosin and tilmicosin were observed. Interestingly, seven isolates showed very high MIC values of lincomycin and tilmicosin, but not all of them showed very high MIC values of tylosin. Most of the MS isolates showed low MIC values of spiramycin, but seven strains showed a MIC ≥16 μg/mL. In the observation period, the frequency of the different MIC classes varied dependently on the tested antibiotic. Interestingly, tilmicosin MICs clearly showed a time-dependent progressive shift towards high-concentration classes, indicative of an on-going selection process among MS isolates. Until standardized breakpoints become available to facilitate data interpretation, it will be fundamental to continue studying MIC value fluctuations in the meantime in order to create a significant database that would facilitate veterinarians in selecting the proper drug for treating this impactful Mycoplasma.

Topics: Animals; Anti-Bacterial Agents; Bacterial Proteins; Diterpenes; Doxycycline; Enrofloxacin; Erythromycin; Italy; Lectins; Lincomycin; Microbial Sensitivity Tests; Mycoplasma synoviae; Oxytetracycline; Poultry; Spiramycin; Thiamphenicol; Tylosin

The cfr gene was identified in three linezolid-resistant USA300 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected over a 3-day period at a New York City medical center in 2011 as part of a routine surveillance program. Each isolate possessed a plasmid containing a pSCFS3-like cfr gene environment. Transformation of the cfr-bearing plasmids into the S. aureus ATCC 29213 background recapitulated the expected Cfr antibiogram, including resistance to linezolid, tiamulin, clindamycin, and florfenicol and susceptibility to tedizolid.

Topics: Acetamides; Anti-Bacterial Agents; Bacterial Proteins; Clindamycin; Diterpenes; Drug Resistance, Multiple, Bacterial; Gene Transfer Techniques; Humans; Linezolid; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Molecular Sequence Data; New York; Organophosphates; Oxazoles; Oxazolidinones; Plasmids; Staphylococcal Infections; Thiamphenicol

Limited data regarding the susceptibility of Actinobacillus pleuropneumoniae to antimicrobials has been published during recent years. Accordingly, the aim of the present study was to investigate the distribution of MICs for the isolates of A. pleuropneumoniae from diseased pigs in the Czech Republic between 2007 and 2009. A total of 242 isolates were tested for susceptibility to 16 antimicrobial agents by a broth microdilution method. A low degree of resistance was observed for florfenicol (0.8%), amoxicillin and clavulanic acid (0.8%), tilmicosin (1.2%), tiamulin (1.7%) and ampicillin (3.3%), whereas resistance to tetracycline was detected more frequently, 23.9% of isolates. Interestingly, resistance to florfenicol has not yet been reported in any study investigating antimicrobial resistance of A. pleuropneumoniae. By PCR the presence of the floR gene was confirmed in all florfenicol resistant isolates.

Topics: Actinobacillus pleuropneumoniae; Amoxicillin; Ampicillin; Animals; Anti-Bacterial Agents; Clavulanic Acid; Czech Republic; Diterpenes; Genes, Bacterial; Microbial Sensitivity Tests; Swine; Swine Diseases; Tetracycline; Thiamphenicol; Tylosin

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

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