Antimicrobial susceptibility, plasmid profiles and haemocin activities of Avibacterium paragallinarum strains.
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.
Hsu
Yuan-Man
YM
Department of Biological Science and Technology, China Medical University, 91, Hsueh-Shih Road, Taichung 404, Taiwan. yuanmh@mail.cmu.edu.tw
Shieh
Happy K
HK
Chen
Wei-Hao
WH
Sun
Tsung-Yu
TY
Shiang
Jia-Hsiang
JH
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
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D004269:DNA, Bacterial; C030520:haemocin