The aim of this study was to evaluate the physiological effects of tylosin in rats. Tylosin was administered orally to pubertal male and female rats at concentrations of 0.005, 0.2, 10 and 200 mg/kg b.w. for 6 weeks. The overall body and organ weights were recorded. Serum levels of immunoglobulins, haematological values, histopathological lesions in different organs, and gene expression profiles in pituitary glands were investigated. The mean platelet volume was increased, and the monocyte count was decreased significantly in both male and female rats treated with tylosin. Compared to the untreated control, alanine transaminase in both types of rats and total serum bilirubin in female rats were increased significantly with the administration of tylosin (200 mg/kg), however, lactate dehydrogenase in female rats was decreased. The levels of immunoglobulin M were reduced in both male and female rats but immunoglobulin G levels were significantly reduced only in female rats which were treated with tylosin. Cell proliferation- and adhesion-associated genes were expressed more but apoptosis gene expressions were decreased in the pituitary gland of tylosin-treated rats. In conclusion, this study revealed that the use of tylosin at therapeutic dosage is possibly not completely safe.
- MeSH
- antibakteriální látky klasifikace škodlivé účinky toxicita MeSH
- hodnocení léčiv * metody veterinární MeSH
- nežádoucí účinky léčiv veterinární MeSH
- potkani Wistar metabolismus MeSH
- testy toxicity metody veterinární MeSH
- tylosin * aplikace a dávkování škodlivé účinky toxicita MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- klinická studie MeSH
- práce podpořená grantem MeSH
To evaluate the microbiological safety of tilmicosin on human intestinal microflora, four chemostat models of healthy human colonic ecosystems were exposed to tilmicosin (0, 0.436, 4.36, and 43.6 μg/mL) for 7 days. Prior to and during drug exposure, three microbiological endpoints were monitored daily including short-chain fatty acids, bacterial counts and macrolide susceptibility. Colonization resistance of each community was determined by 3 successive daily challenges of Salmonella typhimurium. Genes associated with virulence and macrolide resistance in Enterococcus faecalis were determined by PCR. Transcriptional expression of the virulence gene (gelE) in E. faecalis was determined by real-time RT-PCR. Our results showed that different concentrations of tilmicosin did not disrupt the colonization resistance in each chemostat. During exposure to 4.36 and 43.6 μg/mL tilmicosin, the Bacteroides fragilis population was significantly decreased while the proportion of resistant Enterococci increased. After long-term exposure to the highest concentration (43.6 μg/mL) of tilmicosin, the gelE gene was significantly up-regulated in the high-level macrolide resistant strains that also contained the ermB resistance gene. This study was the first of its kind to evaluate the microbiological toxicity of tilmicosin using a chemostat model. These findings also provide new insight into the co-occurrence of macrolide resistance and virulence in E. faecalis under tilmicosin selective pressure.
- MeSH
- antibakteriální látky škodlivé účinky MeSH
- Bacteroides fragilis účinky léků genetika MeSH
- bakteriální geny genetika MeSH
- Enterococcus faecalis účinky léků genetika MeSH
- feces mikrobiologie MeSH
- kolon mikrobiologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti metody MeSH
- Salmonella typhimurium účinky léků genetika MeSH
- střevní mikroflóra účinky léků genetika MeSH
- tylosin škodlivé účinky analogy a deriváty MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The influence of specific and non-specific antibiotic pressure on in vivo spread of macrolide-lincosamide-streptogramin B (MLSB) resistance was evaluated in this study. Chickens repeatedly inoculated with Enterococcus faecalis harbouring the plasmid pAMβ1 carrying the erm(B) gene were perorally treated for one week with tylosin, lincomycin (both specific antibiotic pressure) and chlortetracycline (non-specific antibiotic pressure). Antibiotic non-treated but E. faecalis inoculated chickens served as a control. To quantify the erm(B) gene and characterise intestinal microflora, faecal DNA was analysed by qPCR and 454-pyrosequencing. Under the pressure of antibiotics, a significant increase in erm(B) was observed by qPCR. However, at the final stage of the experiment, an increase in erm(B) was also observed in two out of five non-treated chickens. In chickens treated with tylosin and chlortetracycline, the increase in erm(B) was accompanied by an increase in enterococci. However, E. faecalis was at the limit of detection in all animals. This suggests that the erm(B) gene spread among the gut microbiota other than E. faecalis. Pyrosequencing results indicated that, depending on the particular antibiotic pressure, different bacteria could be responsible for the spread of MLSB resistance. Different species of MLSB-resistant enterococci and streptococci were isolated from cloacal swabs during and after the treatment. PFGE analysis of MLSB-resistant enterococci revealed four clones, all differing from the challenge strain. All of the MLSB-resistant isolates harboured a plasmid of the same size as pAMβ1. This study has shown that MLSB resistance may spread within the gut microbiota under specific and non-specific pressure and even in the absence of any antimicrobial pressure. Finally, depending on the particular antibiotic pressure, different bacterial species seems to be involved in the spread of MLSB resistance.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence genetika MeSH
- chlortetracyklin farmakologie MeSH
- DNA primery genetika MeSH
- druhová specificita MeSH
- Enterococcus faecalis účinky léků genetika MeSH
- feces mikrobiologie MeSH
- grampozitivní bakteriální infekce veterinární MeSH
- kur domácí * MeSH
- linkosamidy farmakologie MeSH
- makrolidy farmakologie MeSH
- methyltransferasy genetika MeSH
- mikrobiální testy citlivosti MeSH
- molekulární sekvence - údaje MeSH
- nemoci drůbeže mikrobiologie MeSH
- neparametrická statistika MeSH
- plazmidy genetika MeSH
- polymerázová řetězová reakce veterinární MeSH
- přenos genů horizontální genetika MeSH
- pulzní gelová elektroforéza veterinární MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- streptogramin B farmakologie MeSH
- tylosin farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- Ko-amoxicilin, Sultamicilin,
- MeSH
- antibakteriální látky aplikace a dávkování farmakologie terapeutické užití MeSH
- azithromycin aplikace a dávkování farmakologie terapeutické užití MeSH
- bakteriální infekce farmakoterapie MeSH
- bakteriální léková rezistence MeSH
- dítě MeSH
- fixní kombinace léků MeSH
- klarithromycin aplikace a dávkování farmakologie terapeutické užití MeSH
- kombinace amoxicilinu a kyseliny klavulanové aplikace a dávkování farmakologie terapeutické užití MeSH
- lékové předpisy MeSH
- lidé MeSH
- makrolidy MeSH
- sulbaktam aplikace a dávkování farmakologie terapeutické užití MeSH
- tylosin analogy a deriváty MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
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.
- MeSH
- Actinobacillus pleuropneumoniae účinky léků izolace a purifikace MeSH
- amoxicilin farmakologie MeSH
- ampicilin farmakologie MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální geny MeSH
- diterpeny farmakologie MeSH
- kyselina klavulanová farmakologie MeSH
- mikrobiální testy citlivosti MeSH
- nemoci prasat epidemiologie mikrobiologie MeSH
- prasata mikrobiologie MeSH
- tetracyklin farmakologie MeSH
- thiamfenikol analogy a deriváty farmakologie MeSH
- tylosin analogy a deriváty farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- chromatografie iontoměničová MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- gelová chromatografie MeSH
- izoenzymy chemie izolace a purifikace metabolismus MeSH
- oxidoreduktasy aminokyselin chemie izolace a purifikace metabolismus MeSH
- Streptomyces enzymologie MeSH
- tylosin biosyntéza MeSH
- Publikační typ
- srovnávací studie MeSH
