title: Use of a proposed antimicrobial susceptibility testing method for Haemophilus parasuis.
abstract: The aim of this study was to examine the antimicrobial susceptibility of 97 Haemophilus parasuis cultured from Australian pigs. As there is no existing standard antimicrobial susceptibility technique available for H. parasuis, methods utilising the supplemented media, BA/SN for disc diffusion and test medium broth (TMB) for a microdilution technique, were initially evaluated with the reference strains recommended by the Clinical and Laboratory Standards Institute. The results of the media evaluation suggested that BA/SN and TMB can be used as suitable media for susceptibility testing of H. parasuis. The proposed microdilution technique was then used with 97 H. parasuis isolates and nine antimicrobial agents. The study found that Australian isolates showed elevated minimum inhibitory concentrations (MICs) for ampicillin (1%), penicillin (2%), erythromycin (7%), tulathromycin (9%), tilmicosin (22%), tetracycline (31%) and trimethoprim-sulfamethoxazole (40%). This study has described potential antimicrobial susceptibility methods for H. parasuis and has detected a low percentage of Australian H. parasuis isolates with elevated antimicrobial MICs.
authors.affiliation: The University of Queensland, School of Veterinary Science, Gatton, Qld, 4343, Australia. Electronic address: d.dayao@uq.edu.au.
authors.forename: Denise Ann E
authors.initials: DA
authors.lastname: Dayao
authors.affiliation: Department of Agriculture Fisheries and Forestry, EcoSciences Precinct, Dutton Park, Qld, 4102, Australia; The University of Queensland, School of Agriculture and Food Sciences, St Lucia, Qld, 4072, Australia.
authors.forename: Marco
authors.initials: M
authors.lastname: Kienzle
authors.affiliation: The University of Queensland, School of Veterinary Science, Gatton, Qld, 4343, Australia.
authors.forename: Justine S
authors.initials: JS
authors.lastname: Gibson
authors.affiliation: The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, EcoSciences Precinct, Dutton Park, Qld, 4102, Australia.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Blackall
authors.affiliation: The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, EcoSciences Precinct, Dutton Park, Qld, 4102, Australia.
authors.forename: Conny
authors.initials: C
authors.lastname: Turni
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001431:Bacteriological Techniques / Q000662:veterinary*; D024881:Drug Resistance, Bacterial; D044137:Haemophilus parasuis / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests / Q000592:standards
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antimicrobial susceptibility testing; BA/SN; Glässer's disease; Haemophilus parasuis; Test medium broth (TMB)