title: Antimicrobial susceptibility, plasmid profiles and haemocin activities of Avibacterium paragallinarum strains.
abstract: In this study, 18 Avibacterium paragallinarum isolates collected in Taiwan from 1990 to 2003 were serotyped and tested for resistance to antimicrobial agents. Serotyping revealed that 13 isolates were Page serovar A and 5 isolates were Page serovar C. More than 75% of the isolates were resistant to neomycin, streptomycin and erythromycin. The most common resistance pattern (15 isolates, 83.3%) was neomycin-streptomycin. Furthermore, 88.9% of the isolates were resistant to two or more antibiotics. About 72% of isolates contained plasmids (pYMH5 and/or pA14). Plasmid pYMH5 encoded functional streptomycin, sulfonamide, kanamycin and neomycin resistance genes and revealed significant homology to a broad host-range plasmid, pLS88. Plasmid pA14 encoded a putative MglA protein and RNase II, both of which might be associated with virulence. Furthermore, seven isolates showed haemocin activity. Plasmid pYMH5 is the first multidrug-resistance plasmid reported in A. paragallinarum and it may facilitate the spread of antibiotic-resistance genes between bacteria. The putative virulence plasmid pA14 and haemocin-like activity in A. paragallinarum indicate two possible mechanisms which might be responsible for the pathogenesis.
authors.affiliation: Department of Biological Science and Technology, China Medical University, 91, Hsueh-Shih Road, Taichung 404, Taiwan. yuanmh@mail.cmu.edu.tw
authors.forename: Yuan-Man
authors.initials: YM
authors.lastname: Hsu
authors.forename: Happy K
authors.initials: HK
authors.lastname: Shieh
authors.forename: Wei-Hao
authors.initials: WH
authors.lastname: Chen
authors.forename: Tsung-Yu
authors.initials: TY
authors.lastname: Sun
authors.forename: Jia-Hsiang
authors.initials: JH
authors.lastname: Shiang
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000378:metabolism*; D001483:Base Sequence; D002645:Chickens; D015169:Colony Count, Microbial / Q000662:veterinary; D004269:DNA, Bacterial / Q000737:chemistry; D004196:Disease Outbreaks / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005784:Gene Amplification; D006192:Haemophilus Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary; D044134:Haemophilus paragallinarum / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity*; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D010957:Plasmids / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011201:Poultry Diseases / Q000453:epidemiology / Q000382:microbiology; D012703:Serotyping / Q000662:veterinary; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D004269:DNA, Bacterial; C030520:haemocin