In vitro activities of spectinomycin and comparator agents against Pasteurella multocida and Mannheimia haemolytica from respiratory tract infections of cattle
Objectives: Prior to the renewal of spectinomycin licensing for veterinary uses in Germany, 154 Pasteurella multocida and 148 Mannheimia haemolytica strains from respiratory tract infections in cattle were investigated for their MICs of spectinomycin and other antimicrobial agents. The data obtained...
Saved in:
Published in | Journal of antimicrobial chemotherapy Vol. 53; no. 2; pp. 379 - 382 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Oxford
Oxford University Press
01.02.2004
Oxford Publishing Limited (England) |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Objectives: Prior to the renewal of spectinomycin licensing for veterinary uses in Germany, 154 Pasteurella multocida and 148 Mannheimia haemolytica strains from respiratory tract infections in cattle were investigated for their MICs of spectinomycin and other antimicrobial agents. The data obtained should serve as a baseline from which to judge the future development of resistance. Moreover, the in vitro activity of spectinomycin in comparison with other antimicrobials should be assessed. Methods: MIC determination for all 302 strains was performed by the broth dilution method and evaluated according to NCCLS standards. MIC50 and MIC90 values were calculated. Strains resistant to spectinomycin were subjected to PCR assays for genes known to mediate spectinomycin resistance in Gram-negative and Gram-positive bacteria. Results: With the exception of resistance to sulfamethoxazole in P. multocida and M. haemolytica, and resistance to ampicillin in M. haemolytica, an overall low level of resistance was detected. A total of 93.5% of the P. multocida and 98.6% of the M. haemolytica strains were susceptible to spectinomycin, with MIC90s of 32 mg/L. PCR analysis showed that none of the spectinomycin-resistant strains carried any of the aadA gene subtypes, nor the genes spc or aad(9). Conclusions: Prior to the renewal of spectinomycin, only a small number of spectinomycin-resistant strains was detected among bovine P. multocida and M. haemolytica. The genes responsible for spectinomycin resistance in these strains seemed to be different from those so far known to occur in other Gram-negative and Gram-positive bacteria. |
---|---|
Bibliography: | istex:47034BA99E7368F89E639DA14CE61B005CD3A1EA local:dkh059 ark:/67375/HXZ-10V5MG1V-Z Received 15 July 2003; returned 1 October 2003; revised 3 November 2003; accepted 6 November 2003 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0305-7453 1460-2091 1460-2091 |
DOI: | 10.1093/jac/dkh059 |