ABSTRACT
368 streptococcal strains from udder secretions of cattle (Sc. agalactiae, Sc. dysgalactiae, Sc. uberis) and 191 streptococcal isolates from horse specimens (Sc. equi ssp. zooepidemicus, Sc. equi ssp. equi) originating from different agricultural regions in Germany (Lower Saxony, in particular the region of Weser-Ems, Bavaria, Altmark) were investigated for their sensitivity to 4 beta-lactam antibiotics (benzylpenicillin, ampicillin, oxacillin, cefotaxime). Two different test methods were applied: the agar diffusion test for determination of the diameter of the zone of inhibition and the E-test for determination of the minimal inhibitory concentration (MIC). According to the evaluation code of DIN 58,940, 98% to 100% of the isolates from the cow udder as well as of the Streptococcus strains from horses were sensitive to the four antibiotics tested. Only Sc. uberis was less sensitive to benzylpenicillin (79.7%) and Oxacillin (83.2%). The strains from different agricultural regions did not differ from each other concerning their sensitivity to beta-lactams. The results of the two methods of sensitivity testing were in satisfactory agreement: Compared to the MIC reference values, misclassifications occurred in the agar diffusion test only at an error rate of between 1.62% (for ampicillin) and 5.21% (for benzylpenicillin).
Subject(s)
Anti-Bacterial Agents/pharmacology , Mammary Glands, Animal/microbiology , Streptococcus/drug effects , Ampicillin/pharmacology , Animals , Cattle , Cefotaxime/pharmacology , Female , Germany , Horses , Mammary Glands, Animal/metabolism , Microbial Sensitivity Tests/methods , Oxacillin/pharmacology , Penicillin G/pharmacology , Streptococcus/isolation & purificationABSTRACT
Antibiograms received from veterinary laboratories during the 1990-1994 period were recorded and evaluated with the aid of a computer program. Based on 70 tables giving information about th most important pathogens, the resistance behaviour of E. coli in cattle, swine, chicken, and turkey, that of Pasteurella haemolytica and P. multocida in cattle and swine and that of Staphylococcus aureus and Streptococcus agalactiae in cattle have been in synoptic form. Attention is drawn to the increase in resistance to enrofloxacin shown by E. coli, particularly in turkeys.
Subject(s)
Animals, Domestic , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Bacterial Infections/veterinary , Animals , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Bacterial Infections/microbiology , Cattle , Chickens , Drug Resistance, Microbial , Germany , Swine , TurkeysABSTRACT
On the basis of results of sensitivity tests carried out in 1992 by means of a standardized agar diffusion test according to DIN 58,940 by 28 laboratories performing routine diagnosis, frequency of resistance was evaluated in the form of rank orders. For "calculated" chemotherapy, the choice of the substance to be applied is determined by the sensitivity of the presumptive pathogen, if laboratory results relating to the agent are (still) lacking. Evaluation of the pathogens tested (clostridia, E. coli, pasteurellas, salmonellas, staphylococci, streptococci) has made it evident that, due to a wide distribution of resistance factors against benzylpenicillins, tetracyclines, chloramphenicol, streptomycin, macrolides and sulfonamides, the range of antibiotics for the (uncontrolled) first application has become even narrower. A testing of the pathogen in the antibiogram remains an urgent necessity.
Subject(s)
Animals, Domestic/microbiology , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Bacterial Infections/veterinary , Animals , Bacterial Infections/microbiology , Drug Resistance, Microbial , Microbial Sensitivity Tests/veterinaryABSTRACT
The national strategy for the use of chemotherapeutics under which there is a distinction between therapeutics and growth promoters for all uses (human medicine, veterinary medicine, animal nutrition) has resulted in a distinct reduction of the selection pressure and a decrease of the OTC resistance among Enterobacteriaceae in the eastern German Länder (formerly GDR) due to a reduction of OTC feeding after 1981 and the final prohibition in 1983. In the following years Enterobacteriaceae were investigated as infectious pathogens for humans and animals using antibiograms. On the one hand, the OTC resistance of porcine and bovine E. coli strains decreased only by 27% and 17%, respectively, during the 1980 to 1988 period, on the other, the OTC resistance of bovine S. typhimurium dropped by 65%, porcine S. typhimurium by 50%, bovine S. dublin by 50%, porcine S. choleraesuis by 30% to a resistance level of about 13% (1989) demonstrating a reduced pressure of resistance. At the same time, OTC resistance became diminished from 50% and 70%, respectively, to 30% also in Enterobacteriaceae (E. coli, Klebsiella) and enterococci isolated from urine and wound infections of patients in the non-agricultural population although therapeutic habits had remained unchanged. The results shown point to a spreading of resistance plasmids which has to be expected far beyond the field of OTC use, for example after the use of antibacterial growth promoters in livestock farming. Control measures should be introduced.
