Minimum inhibitory concentrations of tulathromycin against respiratory bacterial pathogens isolated from clinical cases in European cattle and swine and variability arising from changes in in vitro methodology.
The in vitro activity of tulathromycin was evaluated against common bovine and porcine respiratory pathogens collected from outbreaks of clinical disease across eight European countries from 1998 to 2001. Minimum inhibitory concentrations (MICs) for one isolate of each bacterial species from each outbreak were determined using a broth microdilution technique. The lowest concentrations inhibiting the growth of 90% of isolates (MIC90) for tulathromycin were 2 microg/ml for Mannheimia (Pasteurella) haemolytica, 1 microg/ml for Pasteurella multocida (bovine), and 2 microg/ml for Pasteurella multocida (porcine) and ranged from 0.5 to 4 microg/ml for Histophilus somni (Haemophilus somnus) and from 4 to 16 microg/ml for Actinobacillus pleuropneumoniae. Isolates were retested in the presence of serum. The activity of tulathromycin against fastidious organisms was affected by culture conditions, and MICs were reduced in the presence of serum.
Godinho
Kevin S
KS
Veterinary Medicine Research and Development, Pfizer Ltd, Sandwich, Kent, UK.
Keane
Sue G
SG
Nanjiani
Ian A
IA
Benchaoui
Hafid A
HA
Sunderland
Simon J
SJ
Jones
M Anne
MA
Weatherley
Andrew J
AJ
Gootz
Thomas D
TD
Rowan
Tim G
TG
D016977:Actinobacillus pleuropneumoniae / Q000187:drug effects / Q000302:isolation & purification; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002417:Cattle; D004187:Disaccharides / Q000494:pharmacology* / Q000627:therapeutic use; D005060:Europe / Q000453:epidemiology; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D044138:Haemophilus somnus / Q000187:drug effects / Q000302:isolation & purification; D006571:Heterocyclic Compounds / Q000494:pharmacology* / Q000627:therapeutic use; D066298:In Vitro Techniques; D016978:Mannheimia haemolytica / Q000187:drug effects / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D016979:Pasteurella multocida / Q000187:drug effects / Q000302:isolation & purification; D012766:Pasteurellosis, Pneumonic / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D013552:Swine; D013553:Swine Diseases / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D018942:Macrolides
D000900:Anti-Bacterial Agents; D004187:Disaccharides; D006571:Heterocyclic Compounds; C485204:tulathromycin; D018942:Macrolides