title: Antimicrobial susceptibility pattern of Helicobacter suis strains.
abstract: Helicobacter suis is a very fastidious porcine gastric pathogen, which is also considered to be of zoonotic importance. In vitro antimicrobial susceptibility cannot be determined using standard assays, as this agent only grows in a biphasic medium with an acidic pH. Therefore, a combined agar and broth dilution method was used to analyse the activity of nine antimicrobial agents against nine H. suis isolates. After 48 h microaerobic incubation, minimal inhibitory concentrations (MICs) were determined by software-assisted calculation of bacterial growth. Only for enrofloxacin a bimodal distribution of MICs was demonstrated, indicating acquired resistance in one strain, which showed an AGT→AGG (Ser→Arg) substitution at codon 99 of gyrA. In conclusion, the assay developed here is suitable for determination of the antimicrobial susceptibility of H. suis isolates, although activity of acid sensitive antimicrobial agents may be higher than predicted from MIC endpoints.
authors: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. miet.vermoote@ugent.be
authors: Miet
authors: M
authors: Vermoote
authors: Frank
authors: F
authors: Pasmans
authors: Bram
authors: B
authors: Flahou
authors: Kim
authors: K
authors: Van Deun
authors: Richard
authors: R
authors: Ducatelle
authors: Freddy
authors: F
authors: Haesebrouck
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D000077422:Enrofloxacin; D024841:Fluoroquinolones / Q000494:pharmacology; D018247:Helicobacter heilmannii / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D013552:Swine
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D000077422:Enrofloxacin