ABSTRACT
This case study describes the isolation ofa multiresistant strain ofBrachyspira hyodysenteriae in April 2007 in a Dutch sow herd with recurrent diarrhoea. Examination of faecal samples taken from 7-month-old breeding gilts with diarrhoea revealed the presence of resistance against tiamulin, lincomycin, tylosin, doxycycline, and tylvalosin (the active substance in Aivlosin) in four of five samples. Tiamulin resistance has not been reported in The Netherlands before. The repeated use of tiamulin on the affected farm was assumed to be the main cause of the development of resistance to the drug. The farmer was advised to adopt a medication strategy and to implement management practices that would prevent an ongoing cycle of infection on the farm. It is important that the Dutch swine industry appreciates that tiamulin-resistant strains of B. hyodysenteriae may be found on other farms as well. The appropriate and prudent use of antibiotics is essential in order to prevent the development of resistance against the last option left to cure B. hyodysenteriae infections: valnemulin.
Subject(s)
Anti-Bacterial Agents/pharmacology , Brachyspira hyodysenteriae/drug effects , Drug Resistance, Multiple, Bacterial , Gram-Negative Bacterial Infections/veterinary , Swine Diseases/drug therapy , Animals , Anti-Bacterial Agents/therapeutic use , Brachyspira hyodysenteriae/isolation & purification , Colony Count, Microbial/veterinary , Diarrhea/drug therapy , Diarrhea/epidemiology , Diarrhea/microbiology , Diarrhea/veterinary , Diterpenes/pharmacology , Diterpenes/therapeutic use , Dose-Response Relationship, Drug , Female , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/epidemiology , Gram-Negative Bacterial Infections/microbiology , Male , Microbial Sensitivity Tests/veterinary , Netherlands/epidemiology , Prevalence , Swine , Swine Diseases/epidemiology , Swine Diseases/microbiology , Treatment OutcomeABSTRACT
Intrathecal (IT) administration of acetyl cholinesterase inhibitors produces analgesia through a muscarinic action. The addition of IT cholinergic agonists to IT opioids or alpha 2-adrenergic agonists results in enhanced analgesic effects, but it is not clear whether these interactions are synergistic, additive, or less than additive. Dose-response curves for hot plate and tail immersion tests were established for IT neostigmine, physostigmine, and echothiophate in rats. Dose-response curves for hot plate testing were established for IT morphine and clonidine. The effect of maximally effective doses of each of the three cholinergic drugs on hot plate testing was plotted over time. Isobolographic analysis was performed for hot plate testing using neostigmine-morphine and neostigmine-clonidine combinations. The three cholinesterase inhibitors produced profound analgesia on hot plate testing but incomplete analgesia using the tail immersion test. Duration of analgesia on hot plate testing ranged from 45 min for physostigmine to more than 24 h for echothiophate. IT administration of combinations of neostigmine plus morphine and neostigmine plus clonidine both produced significantly more profound analgesia than the calculated additive effects and are, therefore, synergistic in their actions.
Subject(s)
Analgesia/methods , Cholinesterase Inhibitors/administration & dosage , Clonidine/administration & dosage , Morphine/administration & dosage , Animals , Dose-Response Relationship, Drug , Drug Synergism , Injections, Spinal , Male , Pain Measurement/drug effects , Rats , Rats, Sprague-DawleyABSTRACT
Intraoperative radiation therapy (IORT) research is limited by the lack of small-animal models. We have implanted B16 melanoma into mouse kidneys, which we subsequently operated upon and irradiated with beta rays from a 90Sr ophthalmic applicator. The IORT has effectively prolonged survival and produced some cures. The strategy should be applicable to other murine tumors and to other internal implantation sites.
